Safety shield for syringe

Abstract

If the syringe is removed from the injection site prematurely, the needle will not be exposed. The syringe includes a housing with a longitudinal axis. The housing accommodates a medication container containing a medication. A hole is provided at a distal end of the housing for receiving a portion of a needle operably coupled to the medication container. At least a distal portion of the housing is surrounded by a safety shield. The safety shield advances from a retracted position distally relative to the housing to an advanced position that protects the needle. An advancement spring is disposed between the housing and the safety shield. The advancement spring advances the safety shield from the retracted position to the advanced position and is locked to the housing and the safety shield when the safety shield is in the advanced position, thereby preventing the safety shield from returning to the retracted position.

Description

Technical Field

[0001] This application claims priority based on U.S. Provisional Patent Application No. 63 / 174,722, filed on April 14, 2021, the disclosure of which is incorporated herein by reference.

[0002] This application relates to a syringe configured to prevent injury by protecting a hypodermic needle, and a method related thereto.

Background Art

[0003] Syringes such as manual syringes and auto-injectors use hypodermic needles to deliver drugs subcutaneously. Since used hypodermic needles can become a breeding ground for harmful pathogens, syringes must be handled with care and discarded safely. Even if not used correctly or discarded correctly, they can cause injury and may become a source of disease infection.

[0004] Syringes equipped with safety shields are known. The safety shield is configured to protect the hypodermic needle and prevent injury by being placed after injection. However, such a safety shield and the mechanism for placing it can be mechanically complex. As a result, the manufacture and assembly of such syringes can be costly. Furthermore, since the mechanism for placing the safety shield is complex and prone to failure, the effectiveness in preventing injury is reduced.

[0005] Conventional syringes, especially auto-injectors, have another problem. That is, it may be difficult for the user or medical staff to know whether the correct dose of the drug has been completely administered to the patient. This is dangerous. The dose of the drug administered to the patient can be too low (if the injection is incomplete and the user is not aware of it), or too high (if a new dose of the drug is administered again because the injection is incomplete).

[0006] These problems are particularly widespread in auto-injectors used at home. This is because such auto-injectors are generally used by patients (rather than medical staff). Therefore, the risk of misuse is even higher.

[0007] One type of known auto-injector includes a safety mechanism configured as follows. This safety mechanism protects the tip of the hypodermic needle after use by retracting the syringe barrel to house the hypodermic needle into the housing of the syringe when a predetermined amount of drug has been administered. However, if the safety mechanism fails to retract the hypodermic needle properly, the used auto-injector will not be safe. Furthermore, since the safety mechanism retracts the syringe barrel after the injection is completed, the protection of the hypodermic needle is only carried out after the injection is completed.

[0008] As already mentioned, there are also known auto-injectors that include a safety shield and are configured to advance it after use of the auto-injector.

[0009] All of the above types of auto-injectors do not expose the hypodermic needle after the injection is completed. However, in any system, if the syringe is removed from the injection site earlier than expected (for example, before the injection is completed) and there is no indication as to whether the required amount of drug has been administered to the patient, the hypodermic needle may be exposed. Furthermore, the above types of auto-injectors may indicate successful administration after use even if, as a result of being removed from the patient earlier than expected, less than the total amount to be administered subcutaneously has actually been administered. Therefore, there is a need for an improved syringe. SUMMARY OF THE INVENTION

[0010] One embodiment of the invention provides the following syringe. This syringe includes a housing, a safety shield, and a forward spring. The housing is configured to accommodate a drug container containing a drug. The housing has a long axis, and at the tip of the housing, there is an opening for passing a part of the needle operably coupled to the drug container. The safety shield surrounds at least the tip portion of the housing and is configured to move from a retracted position to a forward position on the tip side with respect to the housing to protect the needle. The forward spring is disposed between the housing and the safety shield and is configured to move the safety shield from the retracted position to the forward position and, when the safety shield is in the forward position, to be constrained (locked) between the housing and the safety shield to prevent the safety shield from returning to the retracted position.

[0011] Since the forward spring functions not only as a means for positioning the safety shield but also as a means for locking the safety shield, this syringe is mechanically simple. Therefore, the manufacturing cost is low and the assembly is easy. Further, since both the means for positioning the safety shield and the means for locking it have a small number of components, the possibility of malfunction is low. The forward spring may be a coil spring.

[0012] Hereinafter, the tip of a component means the end of the component that is closer to the injection site during use of the syringe. On the other hand, the proximal end of a component means the end of the component that is farther from the injection site during use of the syringe. Movement in the tip direction means approaching the injection site during use of the syringe, and movement in the proximal direction means moving away from the injection site during use of the syringe.

[0013] Furthermore, the above syringe may include a handle portion attached to the housing and may include drive components for performing an injection. Alternatively, the housing may be configured to be attached to a handle portion that includes drive components for performing an injection. For example, the syringe according to the above embodiment may be formed as a disposable component attached to a reusable handle portion.

[0014] The above syringe may or may not have a medicine container installed inside it.

[0015] The above safety shield may include a sleeve that surrounds at least the tip of the housing. The sleeve may be substantially a closed tube. The proximal end of this tube may be open (for example, there is a wall at the tip but not at the proximal end). Alternatively, the sleeve may include a wall with an opening at the tip. This opening allows the needle to pass through during injection.

[0016] The housing may include a first locking surface, and the safety shield may include a second locking surface. The second locking surface is arranged to face the first locking surface when the safety shield is in the forward position. The forward spring is configured to prevent the safety shield from returning to the retracted position by being locked between the first locking surface and the second locking surface when the safety shield is in the forward position. For example, at least a part of the forward spring may be configured to act as a wedge between the first locking surface and the second locking surface when the safety shield is in the forward position.

[0017] The first locking surface may include a shoulder facing the tip side of the housing, and the second locking surface may include a surface facing the proximal end side of the housing. The second locking surface may be located on the inner surface of the safety shield. A ridge in the direction of the long axis of the housing may extend from the surface facing the proximal end side of the second locking surface in the tip direction. The safety shield (especially its ridge) may be configured to radially compress the forward spring when the safety shield is in the retracted position. The forward spring may be configured to expand radially when it passes through the second locking surface while the safety shield is advancing. Due to this radial expansion, as described above, the forward spring is locked between the first locking surface and the second locking surface.

[0018] The advancing spring may comprise a base end portion of a first diameter and a tip end portion of a second diameter that is narrower than the first diameter. The base end portion is configured to be locked to the housing and the safety shield when the safety shield is in the advanced position. When the safety shield is in the retracted position, the base end portion of the advancing spring may be compressed to a third diameter that is narrower than the first diameter, and when the safety shield is in the advanced position, the advancing spring may be arranged to expand to the first diameter. The safety shield (e.g., its ridge) may be configured to compress the base end portion of the advancing spring to the third diameter when in the retracted position.

[0019] One of the housing and the safety shield may include a retaining tab and the other may include a one-way receiving portion. The retaining tab may be configured to slide over the one-way receiving portion during assembly of the syringe and to contact the one-way receiving portion during advancement of the safety shield so as to prevent the safety shield from separating from the housing. Thus, the retaining tab and the one-way receiving portion can be easily incorporated into the syringe (e.g., by sliding the safety shield in the proximal direction over the housing), and separation of the safety shield from the housing can be prevented when the safety shield is advanced in the distal direction.

[0020] The one-way receiving portion may include an inclined surface arranged to facilitate the retaining tab passing over the one-way receiving portion during assembly of the syringe and a standing cliff surface arranged to prevent the retaining tab passing over the one-way receiving portion during advancement of the safety shield. The inclined surface faces in the distal direction and the cliff surface faces in the proximal direction. Further, the one-way receiving portion may include a cantilevered arm. The inclined surface and the cliff surface may be located at the free end of the arm. In some embodiments, the housing may include the one-way receiving portion and the safety shield may include the retaining tab. In such embodiments, the retaining tab may include a protrusion extending in the circumferential direction. The syringe may include a plurality of, e.g., two, three, or four, cantilevered arms. In this case, the arms may be arranged at equal intervals in the radial direction.

[0021] The housing and the safety shield may be provided with a groove in the direction of the long axis. The groove may be configured such that a ridge extending in the direction of the long axis fits therein. Thereby, rotation of the safety shield with respect to the housing is prevented.

[0022] The syringe may further include a releasable locking mechanism configured to lock the safety shield in the retracted position when it fits into the safety shield.

[0023] The syringe may further include a needle hub (in particular, the connection with the drug container is operable) coupled to the needle and the drug container. The needle hub may be slidably received in the housing. The needle hub may be movable between a first position (retracted position) away from the hole of the housing and a second position (injection position) extending into the hole of the housing with respect to the housing. The needle hub may be configured to release the safety shield by disengaging from the locking mechanism at the second position (injection position).

[0024] For example, the locking mechanism may include a latch surface connected to one of the safety shield and the housing and a flexible latch arm connected to the other. The latch arm may be configured to lock the safety shield in the retracted position by fitting into the latch surface. The needle hub may be configured to release the safety shield by disengaging the latch arm from the latch surface at the second position (injection position).

[0025] The syringe may include a return spring arranged to apply a force towards the first position (retracted position) with respect to the drug container and the needle hub. The return spring may be located between the housing and the drug container. The return spring may be a coil spring. During injection, the needle hub may be movable to the second position (injection position) by the action of, for example, a drive component or a plunger. Further, the syringe may be configured to return the needle hub to the first position (retracted position) following completion of the injection.

[0026] The needle hub may be configured to return to the first position (retracted position) by the action of the return spring in response to the completion of one dose. Thereby, the safety shield may be locked in the retracted position. However, if the syringe is removed from the injection site before the completion of one dose, even if one dose is completed after the removal, the safety shield moves to the forward position before the needle hub returns to the first position (retracted position). The syringe may perform both the first method (return the drug container to the first position (retracted position) in response to the completion of one dose) and the second method (advance the safety shield) in response to being removed from the injection site earlier than planned. Therefore, the activated state of the safety shield indicates that one dose has been administered. For example, the syringe has the following display states. ○ The first display state. It indicates that the syringe has been removed from the injection site after one dose has been completely administered. For example, it indicates that the timing of removing the syringe from the injection site is not earlier than planned. ○ The second display state. It indicates that the timing of removing the syringe from the injection site is earlier than planned and only an incomplete amount has been administered. ○ The third display state. It indicates that the syringe has been removed from the injection site before one dose has been completely administered. For example, it indicates that the timing of removing the syringe from the injection site is earlier than planned.

[0027] The first display state may be the first state after injection of the syringe. The third display state may be the second state after injection of the syringe. The second display state may be a precursor of the second state after injection. These three display states may be visually distinguishable from each other. For example, the syringe may be configured such that when the needle hub moves from the second position (injection position) to the first position (retracted position), the first visible display is exposed. Further, the syringe may be configured such that when the safety shield advances, the second visible display is exposed.

[0028] In another embodiment of the invention, the following syringe is provided. This syringe includes a housing, a safety shield, and a forward spring. The housing is configured to accommodate a medicine container containing medicine and a needle for attaching to the medicine container. The housing has a major axis, and at the proximal end of the housing, there is an opening for passing the needle attached to the medicine container. The safety shield surrounds at least the proximal end portion of the housing and is configured to move forward from a retracted position to a forward position that protects the needle toward the proximal side with respect to the housing. The forward spring is disposed between the housing and the safety shield and is configured to move the safety shield forward. One of the housing and the safety shield is provided with a retaining tab, and the other is provided with a one-way receiving portion. The one-way receiving portion is configured to slide over the retaining tab during the assembly of the syringe and to contact the retaining tab during the forward movement of the safety shield, thereby preventing the safety shield from separating from the housing.

[0029] It will be understood by those skilled in the art that the members described with respect to the features of the above two embodiments can be combined with each other.

[0030] In another embodiment of the invention, the following syringe is provided. This syringe includes a housing, a safety shield, and a forward spring. The housing is configured to accommodate a medicine container. At the distal end of the housing, there is an opening for passing the needle attached to the medicine container. The safety shield surrounds at least the distal end portion of the housing and is configured to move forward from a retracted position to a forward position that protects the needle toward the distal side with respect to the housing. The forward spring is disposed between the housing and the safety shield and is configured to move the safety shield forward from the retracted position to the forward position. The safety shield has a latch surface, and the housing has a flexible latch arm. The latch arm is configured to fit into the latch surface of the safety shield to lock the safety shield in the retracted position and to be releasable from the latch surface during injection.

[0031] As will be understood by the reader, the members described with respect to this embodiment are at least combinable with the members of the embodiment first described.

[0032] The housing may be arranged to accommodate the medicine container and the needle hub. The needle hub is attached to the needle and coupled to the medicine container. Further, the housing may be arranged such that the medicine container and the needle hub are movable between a first position and a second position with respect to the housing. In the first position (retracted position), the needle hub is away from the hole of the housing. In the second position (injection position), the needle hub passes through the hole of the housing. The needle hub may be configured to disengage the latch arm from the latch surface in the second position (injection position).

[0033] In another embodiment of the invention, a method of manufacturing a syringe is provided. This method includes the step of providing a housing having a major axis, the step of providing a safety shield that surrounds at least the tip of the housing and is movable from a retracted position to a forward position that protects the needle toward the tip side with respect to the housing, the step of disposing a forward spring between the housing and the safety shield and configuring the forward spring to advance the safety shield and is provided with. The forward spring is configured to prevent the safety shield from returning to the retracted position by being locked to the housing and the safety shield when the safety shield is in the forward position.

[0034] For example, the method according to this embodiment may be a method of manufacturing a syringe according to any of the above embodiments. Further, this method may include the step of disposing the forward spring inside the safety shield before sliding the safety shield on the housing.

Brief Description of the Drawings

[0035] The invention will be described in more detail in connection with examples of many embodiments shown in the following drawings. However, these drawings do not limit the invention.

[0036]

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[0037] Throughout the detailed description of the invention, the same reference numerals are used for the same parts and the same elements.

Embodiments for Carrying Out the Invention

[0038] The invention disclosed in this specification is directed to syringes, parts for syringes, and methods of assembling or manufacturing them in general. In a first aspect, the invention provides a power pack. This power pack may form part of a drive device. In a second aspect, the invention provides a braking mechanism for a syringe that weakens the power obtained from the power pack. In a third aspect, the invention provides a connecting device for a syringe that connects a needle hub to a drug cartridge. In a fourth aspect, the invention provides a passive safety shield for a syringe that protects the user from the exposed tip of the injection needle.

[0039] The aspects of the invention will be described in order below. These aspects can be implemented independently of each other or in combination. This will become apparent from the following detailed description. For example, any of the embodiments of the power pack described below can be combined with any of the braking mechanisms described in this specification. The power pack may be used without a braking mechanism.

[0040] Similarly, the braking mechanisms described below may be used with a power pack different from those described in this specification. The power pack and the brake (damper) can be used independently of each other, but further advantages will be obtained if the power pack described in this specification is installed in a syringe in combination with the braking mechanism described below. In particular, the power pack according to the invention disclosed in this specification can accommodate a larger driving spring than conventional syringes. The power of the larger driving spring may be weakened using the braking mechanism described in this specification as required.

[0041] The power packs and / or braking mechanisms described in this specification provide additional advantages when incorporated into a syringe equipped with the passive safety shields disclosed in this specification. Additionally, from other aspects of the invention disclosed in this specification, the provision of the safety shield may be provided alone. The provision of the safety shield according to the invention disclosed in this specification may be utilized, as required, in syringes of the types configured as follows. This syringe extends the needle from the housing during injection to administer a single dose of medicine from the needle and then retracts the used needle.

[0042] Finally, it will also be understood that the connecting devices described in this specification may be utilized independently of the syringes described in this specification. The connecting devices described in this specification can be utilized with any device or component provided that the medicine container has a partition configured to be penetrated by the needle. The connecting devices described in this specification can be utilized independently of the other aspects described below, but it will be understood that further advantages can be obtained if combined with one or more of the other aspects disclosed in this specification. In particular, the connecting devices described in this specification can provide additional advantages when combined with the provision of the passive safety shields described below.

[0043] Embodiments according to each of the above aspects will now be described, namely, syringes including examples of power packs, examples of braking mechanisms, examples of connecting devices, and examples of safety shield mechanisms.

[0044] FIG. 1 is a cross-sectional view of a syringe 1001 according to the invention disclosed in this specification. The syringe 1001 includes a handle 1003 at the proximal end and a cover 1006 at the distal end. The handle 1003 houses a drive device 1016 (including a drive spring 1017) and a plunger rod 1015. The distal direction is the direction towards the needle-side end of the syringe, as indicated by arrow A. The proximal direction is opposite to the distal direction and is indicated by arrow B.

[0045] The syringe 1001 shown in FIG. 1 is in a storage state. In this state, the cover 1006 hides the tip of the syringe 1001. The cover 1006 is removable from the syringe 1001 together with the needle cap 1005 and the needle shield 1004, thereby exposing the tip of the syringe 1001. The tip of the syringe 1001 contains a medicine container 1007. The medicine container 1007 is sealed at its proximal end by a plunger 1013 and at its distal end by a partition wall 1008. Medicine M is stored in the medicine container 1007. A needle hub 1011 is coupled to the distal end of the medicine container 1007, and a hypodermic needle 1009 is attached to the needle hub 1011. The needle hub 1011 is translatable with respect to the medicine container 1007. Therefore, when using the syringe 1001, the partition wall 1008 can be penetrated by the hypodermic needle 1009 to establish a flow path between the medicine container 1007 and the hypodermic needle 1009, and injection can be performed. The embodiments disclosed in this specification describe a syringe provided with a cartridge sealed by a partition wall as a medicine container, but it will be understood that some embodiments may replace the container sealed by the partition wall with a syringe barrel with a needle.

[0046] Continuing to refer to FIG. 1, in the state of the syringe shown, the tip of the hypodermic needle 1009 is retracted from the foremost end of the housing 1023. A safety shield 1019 is also provided around the tip of the housing 1023. The safety shield 1019 can be advanced with respect to the housing 1023 after injection depending on the situation.

[0047] Continuing to refer to FIG. 1, the housing 1023 may be removable from the handle 1003. In this case, the housing 1023 and its contents (i.e., the tip of the syringe 1001) can be disposable.

[0048] To perform an injection, the user first removes the cover 1006 from the syringe 1001 (together with the needle cap 1005 and the needle shield 1004). The user then places the tip of the safety shield 1019 on the desired injection site and activates the drive device 1016. When the drive device 1016 is activated, the plunger rod 1015 advances in the tip direction by the action of the driving spring 101. As a result, the needle hub 1011 and the medicine container 1007 advance, so that the hypodermic needle 1009 pierces the injection site. As the plunger rod 1015 continues to advance, the medicine container 1007 further advances, so that the partition wall 1008 is penetrated by the hypodermic needle 1009. Finally, the plunger 1013 advances toward the partition wall 1008 in the medicine container 1007, so that the medicine is discharged from the medicine container 1007 through the hypodermic needle 1009. In this way, the injection is performed. When the plunger rod 1015 reaches the end, the driving spring 1017 separates from the plunger rod 1015, so that the return spring 1021 can operate to retract the medicine container 1007, the needle hub 1011, and the hypodermic needle 1009 in the proximal direction. As a result, the hypodermic needle 1009 retracts and returns into the housing 1023, so that the safety of the syringe 1001 after the injection is completed is ensured. Depending on the situation, the safety shield 1019 advances with respect to the housing 1023 by the action of the forward spring 1025. As a result, the safety shield 1019 becomes a further protective layer.

[0049] FIG. 2 is an external view of the syringe 1001 in FIG. 1, showing the state before injection with the cover 1006 removed in preparation for use. In this state, the housing 1023 and the safety shield 1019 are exposed in preparation for use. As shown in FIG. 2, the syringe 1001 includes a proximal end 1a and a distal end 1b. The distal end 1b may be removable from the proximal end 1a. Among the embodiments, there may be those in which the distal end 1b is disposable and the proximal end 1a is reusable. That is, while the tip portion (including the needle) of the syringe is configured to be usable only once, the base portion (including the drive device) of the syringe may be reusable many times by being connected to a new tip portion each time the syringe is used next. In addition, both the base portion and the tip portion of the syringe may be disposable or reusable.

[0050] [Power pack] Hereinafter, the power pack according to the first aspect of the invention disclosed in this specification will be described.

[0051] The drive device 1016 shown in FIGS. 1 and 2 includes a power pack. This power pack is configured to move the medicine container 1007 and the plunger rod 1015 in the distal direction by the action of the drive spring 1017.

[0052] Generally speaking, the power pack includes a drive spring 1017 installed in the housing 1023, and is configured to be a power source for moving the plunger rod 1015 and the medicine container 1007 in the distal direction to perform an injection. The drive spring 1017 is coupled to the plunger rod 1015 through a mechanism (movement prohibition mechanism, details of which will be described later) that releasably prohibits movement. The movement prohibition mechanism is configured to maintain the drive spring 1017 in a state fitted to the plunger rod 1015 during injection (thereby, the medicine container 1007 and / or the plunger rod 1015 move in the distal direction by the action of the drive spring 1017). The movement prohibition mechanism is further configured to release the plunger rod 1015 from the action of the drive spring after one dose of medicine has been administered from the medicine container 1007.

[0053] The power pack will be described below using the syringe 1001 shown in FIG. 1 as an example. However, it will be understood that the power pack described in this specification can be used with any syringe in which it is desirable for the plunger rod 1015 to be separated from the drive spring 1017.

[0054] FIG. 1 shows the drive spring 1017 in the syringe in the storage state. As shown in FIG. 1, before use of the syringe, the drive spring 1017 is compressed and is in a state (accumulation state) of storing the elastic potential energy for driving the syringe 1001. The drive spring 1017 may be kept in the accumulation state until the syringe 1001 is activated. When the syringe 1001 is activated, the drive spring 1017 can shift to the extended state, and in the process, the plunger rod 1015 of the syringe 1001 is moved.

[0055] The power transmitted by the extension of the drive spring 1017 in the syringe 1001 is generally inversely proportional to the extension of the spring 1017. To ensure that the power is transmitted to the drive spring 1017 over the entire length of the trajectory of the plunger rod 1015, the plunger rod 1015 may be allowed to finish moving while the drive spring 1017 is still somewhat compressed. Therefore, until the drug container 1007 and / or the plunger rod 1015 is released from the action of the drive spring 1017 during injection, the drive spring 1017 holds the drug container 1007 in the tip position within the housing 1023. This may often be undesirable. This is because it may make it difficult to retract the drug container 1007 within the housing 1023 after the injection is completed.

[0056] As will be understood by reading the following more detailed description, the power pack according to the invention disclosed in this specification causes the driving spring 1017 to reliably transmit power to the plunger rod 1015 during injection to administer one dose of medicine, and then subsequently, the driving spring 1017 can be removed from the plunger rod 1015 at the end of its trajectory. As a result, when the injection is completed, the plunger rod 1015 (and the medicine container 1007) does not remain at the tip of the syringe 1001.

[0057] Hereinafter, embodiments of the power pack will be described in more detail with reference to FIGS. 3A - 13.

[0058] FIGS. 3A - 11B show a first embodiment of a syringe 1001 equipped with a power pack 1030 according to the invention disclosed in this specification. FIG. 3A is a cross-sectional view along the long axis of the syringe 1001. FIG. 3B is another cross-sectional view of the syringe 1001. This is a view rotated 45° around the long axis L of the syringe 1001 from the position shown in FIG. 3A. FIGS. 3A and 3B show the storage state of the syringe 1001 before injection. FIGS. 4 - 8 show the following state of the syringe 1001 of FIGS. 3A and 3B. The power pack 1030 advances the plunger rod 1015 and the medicine container 1007 forward in the housing 1023 in the tip direction, releases the plunger rod 1015 from the action of the driving spring 1017, and makes the medicine container 1007 retractable with respect to the housing 1023.

[0059] First, referring to FIG. 3A, the power pack 1030 includes a driving spring 1017 and a movement prohibiting mechanism 1036. The movement prohibiting mechanism 1036 is configured to fit the driving spring 1017 onto the plunger rod 1015. The power pack 1030 is disposed in the proximal housing 1032. The proximal housing 1032 is movably attached within the handle 1003 of the syringe 1001. The handle 1003 also houses an activator 1034. Further details thereof will be described with reference to FIGS. 3B, 12, and 13.

[0060] A spiral coil spring is adopted as the driving spring 1017. This coil spring is coaxially arranged with the plunger rod 1015 and the movement prohibition mechanism 1036. The movement prohibition mechanism 1036 includes a latch mechanism 1038 and a storage cylinder 1044. The latch mechanism 1038 includes a latch 1040 and a protruding portion 1042.

[0061] As shown in FIG. 3A, the plunger rod 1015 may be a composite member composed of a plurality of different parts. Alternatively, the plunger rod 1015 may be an integrally formed product. As shown in FIG. 3A, the proximal end side portion of the main body of the plunger rod 1015 may be hollow. However, this does not prevent the plunger rod 1015 from being substantially a solid material.

[0062] The latch mechanism 1038 is configured to fit the plunger rod 1015 into the driving spring 1017 and is also configured to maintain the driving spring 1017 in an accumulated state until the syringe 1001 is ready for use. At least a part of the latch mechanism 1038 is housed in the cavity inside the driving spring 1017. Since the latch mechanism 1038 is located inside the driving spring 1017, the diameter of the driving spring 1017 can be made larger than when the driving spring 1017 is arranged inside the movement prohibition mechanism 1036. The larger the driving spring 1017 used, the stronger the power can be transmitted to the plunger rod 1015, so that strong power can be transmitted to the plunger rod 1015 throughout the injection, that is, until the driving spring 1017 finishes extending.

[0063] As shown in FIG. 3A, the latch 1040 included in the latch mechanism 1038 is fixed to the protruding portion 1042. Therefore, the latch 1040 and the protruding portion 1042 can move together under the action of the driving spring 1017. The latch mechanism 1038 may be formed as an integrally formed product (including both the latch and the protruding portion), or may be formed by fitting the latch 1040 and the protruding portion 1042, which are separate parts, to each other.

[0064] The latch 1040 includes a fitting portion 1046. The fitting portion 1046 is configured to fit the latch 1040 onto the plunger rod 1015. The fitting portion 1046 is in the form of one arm (or multiple arms). This arm has a latch surface (shown in FIGS. 10A and 10B). The latch surface is configured to engage with the latch surface 1050 of the plunger rod 1015. The arm of the fitting portion 1046 is clearly shown in FIG. 10A and is labeled with reference number 1052.

[0065] The arm 1052 of the fitting portion 1046 can be bent from the position where it engages with the latch surface 1050 of the plunger rod 1015 (as shown in FIG. 3A) in the outer circumferential direction to a position where it no longer engages with the latch surface 1050. However, when the latch mechanism 1038 is in the movement prohibited position as shown in FIG. 3B, the storage cylinder 1044 prevents the fitting portion 1046 from bending outward. This will be further explained later.

[0066] As shown in FIGS. 3A and 3B, the storage cylinder 1044 is accommodated between the fitting portion 1046 and the protruding portion 1042. The storage cylinder 1044 includes a substantially cylindrical body. At least a part of the body forms a locking sleeve 1054. The locking sleeve 1054 is configured to surround the arm 1052 of the fitting portion 1046 when the latch mechanism 1038 is in the positions shown in FIGS. 3A and 3B. Thereby, the arm 1052 is prevented from bending in the outer circumferential direction (or its bending is restricted), so that the fitting portion 1046 is kept in a state of being fitted onto the plunger rod 1015. This position of the latch mechanism 1038 (i.e., the position where the arm of the fitting portion 1046 does not come off the plunger rod 1015) is the movement prohibited position. Due to this engagement, the latch mechanism 1038 can releasably couple the driving spring 1017 to the plunger rod 1015 and transmit the power from the driving spring 1017 to the plunger rod 1015.

[0067] The storage cylinder 1044 also has one or more recesses 1064. These recesses 1064 may be through holes or bottomed recesses, and the arm 1052 of the fitting portion 1046 can bend and enter the space formed by them, so that it can be disengaged from the plunger rod 1015. The latch 1040 is slidably attached to the storage cylinder 1044. When the storage cylinder 1044 reaches a predetermined position, the locking sleeve 1054 and the arm 1052 of the fitting portion 1046 can move relative to each other. At this position, one or more recesses 1064 of the storage cylinder 1044 are assigned to the free end of the arm 1052 of the fitting portion 1046, and the arm 1052 can bend outward. This position of the latch mechanism 1038 is the movement permission position.

[0068] The operation of the movement prohibition mechanism 1036 during the injection process will be described in more detail later with reference to FIGS. 4-8.

[0069] Moving to FIG. 3B, the latch mechanism 1038 may also be hooked on the activator 1034 until the syringe 1001 is activated, keeping the driving spring 1017 in a stored state. The latch 1040 of the latch mechanism 1038 includes at least one engaging element 1056. The engaging element 1056 keeps the driving spring 1017 in a stored state by being releasably fixed in the handle 1003.

[0070] The engaging element 1056 may include a plurality of arms 1058 whose free ends extend in the proximal direction. The arms 1058 may include a latch surface configured to be hooked on the latch surface of the activator 1034. The arms 1058 may be kept in a position where they are hooked on the latch surface of the activator 1034 by the proximal housing 1032.

[0071] When the tip of the driving spring 1017 presses the tip-side flange 1072 of the protruding portion 1042 of the latch mechanism 1038, the latch mechanism 1038 is fixed to the base end of the proximal housing 1032. Thereby, it is prevented that the tip of the driving spring 1017 extends at too early a timing.

[0072] As can also be seen from FIGS. 3A and 3B, the proximal end of the driving spring 1017 presses against the adjacent surface 1073 of the proximal housing 1032. Thus, the driving spring 1017 in the accumulated state is compressed between the distal flange 1072 of the protruding portion 1042 and the proximal adjacent surface 1073 of the proximal housing 1032.

[0073] The proximal housing 1032 may be configured to move between a non-actuated position and an actuated position with respect to the actuator 1034. The arm 1058 of the engaging element 1056 may be configured to be released from a state of being constrained between the proximal housing 1032 and the actuator 1034 by the relative movement between the proximal housing 1032 and the actuator 1034. Thereby, the driving spring 1017 extends in the distal direction and moves the latch mechanism 1038 in the distal direction. The syringe 1001 may include a spring 1075 installed between the proximal housing 1032 and the actuator 1034. The spring 1075 is configured to apply a force to the proximal housing 1032 in the distal direction (i.e., toward the non-actuated position). At the initial stage of injection (as will be described later), the force applied by the user to the syringe 1001 overcomes the force of the spring 1075, moves the proximal housing 1032 proximally with respect to the actuator 1034, and releases the arm 1058 from the engagement between the proximal housing 1032 and the actuator 1034. The interaction between the engaging element 1056 and the actuator 1034 will be described in more detail later with reference to FIGS. 10A - 10C.

[0074] It will be understood that the latch mechanism 1038 may be configured in various different ways. For example, the fitting portion 1046 of the latch 1040 may be provided with only one arm 1052 configured to couple the latch mechanism 1038 to the plunger rod 1015, or may be provided with a plurality as shown. The plurality of arms 1052 may be arranged to form a pair facing each other across the diameter of the syringe 1001, or may be arranged at intervals in the circumferential direction around the major axis L of the syringe 1001.

[0075] Similarly, the latching element 1056 of the latch 1040 may include only one arm 1058 configured to latch the actuator 1034, or may include a plurality of arms as shown. The plurality of arms 1058 may be arranged in pairs facing each other across the diameter of the syringe 1001, or may be arranged circumferentially spaced apart around the long axis L of the syringe 1001. The latching mechanism 1038 may be formed of an elastically deformable material such as a metal material or an elastically deformable polymer.

[0076] The operation of the latching mechanism 1038 during injection will be described in more detail.

[0077] First, as shown in the syringe 1001 of FIG. 4, the cover 1006 (shown in FIG. 1) is removed from the syringe 1001 shown in FIGS. 3A and 3B. The syringe 1001 is placed at the injection site in the state before injection shown in FIG. 4, and the safety shield 1019 is pressed against the injection site.

[0078] As shown in FIG. 5, by the operation of pressing the safety shield 1019 against the injection site, the housing 1023 and the drive device 1016 (including the power pack 1030 and the proximal housing 1032) move toward the proximal side with respect to the handle 1003 inside the handle 1003 (compressing the spring 1075). It will be understood that the movement of the housing 1023 toward the proximal side with respect to the handle 1003 is equivalent to the movement of the handle 1003 toward the distal side with respect to the housing 1023. In other words, since the actuator 1034 is fixed with respect to the handle 1003, when the proximal housing 1032 moves backward with respect to the handle 1003, the actuator 1034 moves from the non-actuated position to the actuated position toward the distal side with respect to the proximal housing 1032. As a result, the latching element 1056 is released from the state of being constrained between the proximal housing 1032 and the actuator 1034.

[0079] The retraction of the proximal housing 1032 in the described embodiment occurs when the user presses the syringe 1001 against the injection site. By this operation, the housing 1023 moves toward the proximal side with respect to the handle 1003. The retraction of the housing 1023 further causes the proximal housing 1032 to move in conjunction through the intermediate housing 1084. However, those skilled in the art will understand that other configurations are possible. For example, the proximal housing and the intermediate housing may be formed as an integrally molded product. Additionally, each of the proximal housing and / or the intermediate housing may be formed from a plurality of parts.

[0080] As shown in FIG. 6, when the syringe 1001 is activated, the driving spring 1017 extends and moves the plunger rod 1015 in the distal direction. When the plunger rod 1015 moves in the distal direction, the medicine container 1007 moves in the distal direction and pierces the needle 1009 into the injection site. Even after the medicine container 1007 has completely moved in the distal direction, the plunger rod 1015 continues to advance (moves toward the distal side with respect to the medicine container 1007), so that the medicine for one dose is discharged from the medicine container 1007 through the needle 1009.

[0081] As can be understood from FIGS. 4-6, at this stage of the injection, since the storage cylinder 1044 moves together with the latch mechanism 1038, the locking sleeve 1054 holds the arm 1052 of the fitting portion 1046 at the position where the latch surface 1050 is hooked on the plunger rod 1015.

[0082] When the storage cylinder 1044 has finished moving as far as it can in the distal direction, it contacts and stops at the adjacent surface 1062 provided on the housing 1023 (see FIG. 7). In the shown embodiment, the adjacent surface 1062 is provided on the intermediate housing 1084. The intermediate housing 1084 is configured to fit into the proximal housing 1032. However, those skilled in the art will understand that the adjacent surface 1062 may be provided on another component such as the housing 1023 or the handle 1003.

[0083] Even after the storage cylinder 1044 reaches the adjacent surface 1062, the latch mechanism 1038 continues to move forward toward the distal end side with respect to the storage cylinder 1044 (as shown in FIG. 7). Due to this forward movement, the arm 1052 of the fitting portion 1046 escapes from the contact state with the locking sleeve 1054 and fits into the recess 1064, i.e., the hole, of the storage cylinder 1044. At this position, the locking sleeve 1054 no longer holds the arm 1052 of the fitting portion 1046 in a state of being caught by the latch surface of the plunger rod 1015, so the arm 1052 bends outward to release the plunger rod 1015. As a result, the movement prohibition mechanism 1036 (shown in FIG. 3A and consisting of the storage cylinder 1044 and the latch mechanism 1038) moves from the movement prohibition position to the movement permission position, separating the plunger rod 1015 from the latch mechanism 1038 and allowing it to escape from the action of the driving spring 1017.

[0084] As shown in FIG. 7, since both the latch surfaces of the plunger rod 1015 and the arm 1052 of the fitting portion 1046 are inclined, the force of the latch 1040 (in the distal direction) pressing the plunger rod 1015 pushes the arm 1052 outward. The only thing that prevents the bending of the arm 1052 due to this force is the locking sleeve 1054 of the storage cylinder 1044. Therefore, after the arm 1052 fits into the recess 1064, the force of the driving spring 1017 pushes the arm 1052 away from the plunger rod 1015, so the plunger rod 1015 is released from the action of the driving spring 1017.

[0085] Finally, as shown in FIG. 8, in a state where the plunger rod 1015 is released from the action of the driving spring 1017, the medicine container 1007 may retract into the used syringe 1001, for example, due to the action of the return spring 1021. The mechanism capable of retracting the medicine container 1007 into the housing 1023 will be described in more detail with reference to FIGS. 47a - 47F.

[0086] The power pack according to the invention disclosed in this specification enables the driving spring to transmit power to the plunger rod through the movement prohibition mechanism by the above method. The movement prohibition mechanism is configured to be able to release the physical connection between the driving spring and the plunger rod. In the initial movement prohibition state, when the driving spring extends, it moves the plunger rod with that force. In the next movement permission state, since the movement prohibition mechanism releases the force of the driving spring from the plunger rod, the plunger rod can then move freely without being fixed by the power of the driving spring.

[0087] Moving on to FIG. 9, the components of the power pack 1030 described with reference to FIGS. 3A - 8 are shown in more detail by the exploded assembly drawing. As shown in FIG. 9, the proximal housing 1032 can be coaxially combined with the driving spring 1017, the latch mechanism 1038 (including the latch 1040 and the overhang portion 1042), the storage cylinder 1044, and the plunger rod 1015. The size of the driving spring 1017 is designed to be equal to or less than the inner diameter of the proximal housing 1032. The size of the overhang portion 1042 is designed to be equal to or less than the inner diameter of the coiled driving spring 1017. The latch 1040 is sized to fit (be inserted) into the overhang portion 1042 with the storage cylinder 1044 positioned between the latch 1040 and the overhang portion 1042. Finally, the size of the plunger rod 1015 is designed to be equal to or less than the inner diameter of the latch 1040.

[0088] The proximal housing 1032 is movably attached to the actuator 1034. The spring 1075 is configured to apply a force to the proximal housing 1032 in the distal direction (towards the non - activation position). In other words, since the spring 1075 is positioned between the proximal housing 1032 and the actuator 1034, it applies a force to the proximal housing 1032 and the actuator 1034 to move them away from each other.

[0089] The storage cylinder 1044 is fitted to the latch mechanism 1038 so as to slide between the latch 1040 and the protruding portion 1042. However, since the latch 1040 and the protruding portion 1042 are pressed radially against the storage cylinder 1044 and caught, the friction between the latch mechanism 1038 and the storage cylinder 1044 prevents the latch mechanism 1038 from sliding in the direction of the long axis of the housing 1023 with respect to the storage cylinder 1044. Since an interference fit is thus achieved between the storage cylinder 1044 and the latch mechanism 1038, sufficient friction is obtained to suppress the latch mechanism 1038 and the storage cylinder 1044 from sliding relative to each other in the direction of the long axis of the housing 1023 when the proximal housing 1032 moves in the distal direction during storage of the syringe 1001 or at the initial stage of its use. However, this friction is weak enough to slide the latch mechanism 1038 relative to the storage cylinder 1044 when the storage cylinder 1044 contacts an adjacent surface (shown by reference numeral 1062 in FIG. 7).

[0090] In this exploded view (FIG. 9), the arm forming the fitting portion 1046 of the latch 1040 can be clearly seen. The arm forming the catching element 1056 of the latch 1040 can also be clearly seen. In FIG. 10A, for the purpose of clearly distinguishing those arms, the arm of the fitting portion 1046 is assigned the reference numeral 1052, and the arm of the catching element 1056 is assigned the reference numeral 1058. In FIG. 9, the latch surfaces at the free ends of these arms can also be seen, as well as the latch surfaces of the plunger rod 1015 associated therewith. However, the reference numerals for the latch surfaces are attached to FIG. 10A for the purpose of making those latch surfaces clear. This is because FIG. 10A shows the latch surfaces of the arms more clearly. In the illustrated embodiment, the latch surface of the plunger rod 1015 is formed as an annular rib 1060 extending circumferentially around the plunger rod 1015. However, it will be understood by those skilled in the art that the continuously circumferential rib 1060 may be replaced by a plurality of discrete latch surfaces.

[0091] The force applied to the plunger by the driving spring is removed when the plunger reaches the end of the track, but this force may be more precisely controlled using a braking mechanism. The braking mechanism is shown in FIGS. 15 - 29. The braking mechanism will be described in more detail later with reference to those drawings.

[0092] Moving on to FIGS. 10A and 10B, two examples of the latch configuration are shown. FIG. 10A shows an example 1040 of the latch shown in FIG. 9. The latch 1040 includes four arms 1058 forming a latching element 1056 and four arms 1052 forming a fitting portion 1046.

[0093] The arms 1058 forming the latching element 1056 extend their free ends from the body 1066 of the latch 1040 in the proximal direction. A locking hook 1068 is provided at the free end of each arm 1058 or on the way thereto. The locking hook 1068 is a portion of the latch 1040 that is constrained between the proximal housing 1032 and the actuator 1034. The constraint of the locking hook 1068 by these will be described in more detail when referring to FIGS. 11A and 11B.

[0094] The arms 1052 forming the fitting portion 1046 extend their free ends from the body 1066 of the latch 1040 in the distal direction. A shoulder 1070 is formed at the free end of each arm 1052 or on the way thereto, and a latch surface 1051 is disposed thereon.

[0095] In the example shown in FIG. 10A, the latching element 1056 includes four arms 1058 and the fitting portion 1046 includes four arms 1052. These arms 1058 and 1052 are alternately arranged at intervals around the body 1066, and the arms 1058 of the latching element 1056 are circumferentially shifted by 45° each from the arms 1052 of the fitting portion 1046.

[0096] Arms 1052 and 1058 are configured to bend during injection to release their respective latch surfaces. In particular, arms 1052 and 1058 may be formed of an elastically deformable material.

[0097] FIG. 10B shows a modification of the latch 1040 shown in FIG. 10A. The latch 1040' in FIG. 10B includes two arms 1058' of the engaging element 1056 and two arms 1052' of the fitting portion 1046. The arms 1058' of the engaging element 1056 face each other with the diameter of the latch 1040 therebetween. The arms 1052' of the fitting portion 1046 face each other with the diameter of the latch 1040 therebetween. Arms 1058' and 1052' are offset from each other in the circumferential direction. Arms 1058' and 1052' may be in any combination of numbers and are not limited to the specific example shown in the drawing. For example, six arms 1058' and 1052' may be provided each, and two arms of the engaging element may be provided while four arms of the fitting portion may be provided.

[0098] FIG. 10C shows the overhanging portion 1042 of the latch 1040 alone. The overhanging portion 1042 includes a tip-side flange 1072. The tip-side flange 1072 extends in the outer circumferential direction, and its surface fits into and contacts the driving spring 1017, thereby transmitting the force of the driving spring 1017 to the latch mechanism 1038. The overhanging portion 1042 includes a sleeve 1074. The sleeve 1074 extends from the tip-side flange 1072 in the base end direction to a wall-like flange 1076. The wall-like flange 1076 includes at least one wall 1078 that extends in the inner circumferential direction from the sleeve 1074. When the latch 1040 is fitted into the overhanging portion 1042, the arms 1058 of the engaging element 1056 of the latch 1040 pass between the walls 1078, so that the walls 1078 compress the main body 1066 of the latch 1040. Thereby, the force of the driving spring 1017 is transmitted to the latch 104 and further transmitted to the rib 1060 of the plunger rod 1015 through the arm 1052 of the fitting portion 1046.

[0099] In the embodiment shown in FIG. 10C, the castellated flange 1076 includes four walls 1078, and four spaces are provided therebetween. Four arms 1058 of the engaging element 1056 can pass through those spaces. It will be understood that the number of walls 1078 (and the number of spaces therebetween) can be adjusted according to the number of arms 1058 of the engaging element 1056 provided on the latch 1040. It will also be understood by those skilled in the art that the number of arms does not necessarily have to be equal to the number of spaces, and there may be more spaces than arms.

[0100] Moving on to FIGS. 11A and 11B, the operation of the actuator 1034 for releasing the latch 1040 will be described in more detail.

[0101] FIG. 11A is a cross-sectional view of the proximal end of the drive device 1016. When the syringe 1001 is in the storage state, the engaging portion 1046 of the latch 1040 is constrained between the proximal housing 1032 in the non-activated position and the actuator 1034.

[0102] As seen in FIG. 11A, the arms 1058 of the engaging element 1056 extend through holes at the proximal end of the proximal housing 1032. The retaining cap 1080 prevents the locking hook 1068 of the arm 1058 from moving in the outer circumferential direction. The retaining cap 1080 covers the proximal end of the proximal housing 1032. However, it will be understood that the main body of the proximal housing 1032 itself may be sized to prevent the arm 1058 from bending outward.

[0103] When the actuator 1034 is in the non-activated position shown in FIG. 11A, the cover surface 1082 of the actuator 1034 prevents the arm 1058 from bending inward. The shape of the locking hook 1068 prevents the arm 1058 from sliding in the direction of its major axis with respect to the proximal housing 1032. Thus, when the actuator 1034 is in the non-activated position shown in FIG. 11A, the arm 1058 is constrained between the proximal housing 1032 and the actuator 1034, preventing the forward movement of the latch mechanism 1038 and keeping the driving spring 1017 in a compressed state.

[0104] The proximal housing 1032 is maintained at a distal position (non-actuated position) with respect to the actuator 1034 by a spring 1075 (shown schematically in FIGS. 11A and 11B). When the user presses the syringe 1001 against the injection site for the purpose of actuating the syringe 1001, the housing 1023 moves proximally with respect to the handle 1003. Subsequently, the proximal housing 1032 moves proximally inside the handle 1003, compressing the spring 1075.

[0105] FIG. 11B shows the proximal housing 1032 in the actuated position. (When the syringe 1001 is pressed against the injection site, at the actuated position, the proximal housing 1032 has moved proximally with respect to the actuator 1034.) At this position, the cover surface 1082 of the actuator 1034 has moved distally with respect to the proximal housing 1032 (compressing the spring 1075), and the locking hook 1068 of the arm 1058 faces the hole 1083, i.e., the recess, of the actuator 1034. When the actuator 1034 is in this position, the arm 1058 can bend freely inward (into the recess), so that the locking hook 1068 disengages from the retaining cap 1080 (i.e., the proximal housing 1032), enabling the latching mechanism 1038 to be advanced by the action of the driving spring 1017.

[0106] The movement inhibiting mechanism is releasable as described above and is configured to release the plunger rod 1015 from the action of the driving spring 1017. It will be understood that this movement inhibiting mechanism may be of a different form. Another embodiment shown in FIG. 12 shows the state of the syringe 2001 before injection. The syringe 2001, similar to the above configuration, includes a handle 2003, a housing 2023, and a safety shield 2019. The syringe 2001 also includes a drive device 2016. The drive device 2016 includes a power pack disposed inside the proximal housing 2032. The power pack includes a driving spring 2017, and the driving spring 2017 is configured to be releasably coupled to the plunger rod 2015 by a movement inhibiting mechanism 2036.

[0107] The movement prohibition mechanism 2036 shown in FIG. 12 includes a storage cylinder 2044 and a latch mechanism 2038. The latch mechanism 2038 is configured to releasably couple a plunger rod 2015 and a driving spring 2017.

[0108] Similar to the above-described embodiment, the latch mechanism 2038 includes a latch 2040 and a protruding portion 2042. The latch 2040 is configured to engage with the latch surface of the plunger rod 2015. The protruding portion 2042 includes a flange that is pressed by the driving spring 2017.

[0109] The configuration of the latch mechanism shown in FIG. 12 is different from the configuration described with reference to FIGS. 3A-11B, but the manner of operation is the same as described below.

[0110] The latch mechanism 2038 includes a fitting portion 2046. The fitting portion 2046 is configured to releasably fit onto the plunger rod 2015 by a bendable arm. The arm is configured to engage with the latch surface of the plunger rod 2015. The latch mechanism 2038 also includes a catching element 2056. The catching element 2056 is configured to releasably hold the latch mechanism 2038 at the proximal end of the syringe 2001 while keeping the driving spring 2017 in an accumulated state by interaction with an activator.

[0111] The movement prohibition mechanism 2036 also includes a storage cylinder 2044. The storage cylinder 2044 holds the arm on the latch surface of the plunger rod 2015 by preventing the arm of the fitting portion 2046 from bending outward. The storage cylinder 2044 shown in FIG. 12 is different from the storage cylinder having a cylindrical main body including a recess (into which the arm of the fitting portion can bend), and includes a locking sleeve 2054. The locking sleeve 2054 is a portion with a first inner diameter and keeps the arm of the fitting portion 2046 in a state of being hooked on the plunger rod 2015. On the tip side of the locking sleeve 2054, the inner diameter of the storage cylinder 2044 is widened (with respect to the locking sleeve 2054), and a space for the arm of the fitting portion 2046 to bend in the outer peripheral direction is formed. The storage cylinder 2044 also includes a pressing surface 2092 on the tip side with respect to the locking sleeve 2054. When the storage cylinder 2044 is moved toward the base end side with respect to the latch mechanism 2038, the pressing surface 2092 acts such that the arm of the fitting portion 2046 moves and disengages from the plunger rod 2015.

[0112] As described below, the syringe 2001 operates in the same manner as the syringe 1001.

[0113] At the start of injection, the syringe 2001 is placed at the injection site and the safety shield 2019 is pressed against the skin. The operation of pressing the safety shield 2019 against the injection site retracts the housing 2023 and the drive device 2016 within the handle 2003, and compresses a starter (not shown) between the drive device 2016 and the handle 2003 to activate the syringe 2001. That is, the syringe 2001 is activated by the starter releasing the driving spring 2017 from the stored state. When the syringe 2001 is activated, the driving spring 2017 extends and moves the plunger rod 2015 in the tip direction.

[0114] The syringe 2001 includes a movement prohibition mechanism 2036, and the movement prohibition mechanism 2036 includes a latch mechanism 2038 and a storage cylinder 2044. The movement prohibition mechanism 2036 shown in FIG. 12 operates in the same manner as the movement prohibition mechanism 1036 described with reference to FIG. 3A.

[0115] In the first stage of injection (when the movement prohibition mechanism is in the "movement prohibited" state), the locking sleeve 2054 with a relatively narrow inner diameter keeps the fitting portion 2046 of the latch 2040 hooked on the plunger rod 2015. However, unlike the storage cylinder 2044 of the syringe 2001 shown in FIG. 12 (as in the above-described embodiment explained with reference to FIGS. 3-10), which has an overall cylindrical main body including a recess for the arm of the fitting portion 2046 to bend, it includes a compression surface 2092. The compression surface 2092 applies a force in the outer circumferential direction to the fitting portion 2046 by bending the arm of the fitting portion 2046 toward the inside of the portion of the storage cylinder 2044 having a diameter larger than that of the locking sleeve 2054, and is configured to actively remove the fitting portion 2046 from the plunger rod 2015. The compression surface 2092 may be configured as a plurality of arms or a conical inclined surface. When the storage cylinder 2044 reaches the adjacent surface 2062 of the housing (since the latch mechanism 2038 continues to move forward), it slides with respect to the latch mechanism 2038 and pushes the fitting portion 2046 away from the plunger rod 2015. The fitting portion 2046 is initially kept hooked on the plunger rod 2015 and then is actively removed from the plunger rod 2015. Therefore, until it is disengaged from the plunger rod 2015, it may be configured to be locked to or firmly hooked on the plunger rod 2015. Thus, the latch mechanism 2038 can be reliably hooked on the plunger rod 2015 and reliably removed from the plunger rod 2015.

[0116] Therefore, in one aspect of the invention disclosed in this specification, the storage cylinder has a compression surface, and the compression surface is configured to push the arm of the fitting portion in the outer circumferential direction to remove it from the plunger rod. In another aspect of the invention, the compression surface may include a plurality of arms or a conical inclined surface. It will also be understood that these features may be combined with the above-described locking sleeve.

[0117] FIG. 13 shows another syringe 3001. The syringe 3001 includes a handle 3003 disposed at the proximal end, a housing 3023, and a cover 3006 disposed at the distal end. The handle 3003 houses a driving device 3016, and the driving device 3016 includes a driving spring 3017 and a forward spring 3099. The driving spring 3017 provides power for discharging the drug from the drug container 3007. However, it does not provide the power to move the drug container 3007 in the distal direction, that is, the power to pierce the skin with the needle, and these powers are provided by another forward spring 3099. When the syringe 3001 is activated, the driving spring 3017 remains in a compressed state, while the forward spring 3099 is released from the compressed state.

[0118] The syringe 3001 can be activated by pressing the safety shield 3019 against the injection site, that is, the skin. By pressing the safety shield 3019 against the injection site, the housing 3023 and the driving device 3016 retreat within the handle 3003, and by releasing the forward spring 3099 from the compressed state, the syringe 3001 is activated.

[0119] When the syringe 3001 is activated, the forward spring 3099 extends and moves the plunger rod 3015 in the tip direction. Due to the action of the forward spring 3099, the plunger rod 3015 moves in the tip direction together with the driving spring 3017. The driving spring 3017 is maintained in the compressed state shown in Fig. 13 between the tip-side adjacent surface 3097 and the base-end-side adjacent surface 3095 (which are arranged at regular intervals). When the forward spring 3099 moves a predetermined distance (which is sufficient to move the medicine container 3007 completely forward but insufficient for drug discharge), the tip-side adjacent surface 3097 is released from a fixed position with respect to the base-end-side adjacent surface 3095, so that the driving spring 3017 is no longer constrained in the compressed state. When the tip-side adjacent surface 3097 is released from the base-end-side adjacent surface 3095, the driving spring 3017 presses the tip-side adjacent surface 3097 and moves it in the tip direction, and then moves the plunger rod 3015 in the tip direction. Thus, after the forward spring 3099 moves the medicine container 3007 to the injection position, the driving spring 3017 becomes extendable, so that power is applied to the plunger rod 3015 to move through the movement prohibition mechanism 3036. The driving spring 3017 is disconnected from the plunger rod 3015 by the releasable movement prohibition mechanism 3036 when it is fully extended or before that. The movement prohibition mechanism 3036 may be the same as the above-mentioned 1036 and 2036, or may be other mechanisms.

[0120] When the plunger rod 3015 moves in the tip direction to the end point of the track (i.e., when all the medicine is administered), the movement prohibition mechanism 3036 can release the plunger rod 3015 from the power of the driving spring 3017.

[0121] The distance by which the forward spring 3099 extends until the driving spring 3017 becomes extendable may be determined as the distance required to move the medicine container 3007 and the needle from the stored position to the fully usable position. In some cases, that distance may be between 10 mm and 20 mm in the tip direction, for example, 18 mm.

[0122] By providing the forward spring 3099 and the driving spring 3017 separately, the power required for the forward movement of the needle is weakened. However, the purpose is not limited to this. For example, using a powerful driving spring for both moving the needle in the tip direction and piercing the injection site and for drug administration may make the user uncomfortable depending on the situation. As a result of using the forward spring 3099 which is weaker than the driving spring 3017, while the needle can be gently advanced in the syringe, drug administration can also be performed quickly.

[0123] Therefore, in one aspect of the invention, the syringe comprises the following. A housing having a long axis. A driving spring installed in the housing. The driving spring has a tip, a base end on the opposite side of the tip along the long axis of the housing, and a cavity formed inside. A plunger at least part of which is installed in the drug container. A plunger rod attached to the plunger. A forward spring. It has a tip and a base end on the opposite side of the tip along the long axis of the housing. An activation mechanism configured to keep both the driving spring and the forward spring in a compressed state. The activation mechanism is also configured as follows. After the syringe is activated, first, the forward spring is released from the compressed state to move the drug container to the tip position by the forward spring, and then, the driving spring is released from the compressed state to move the plunger in the drug container by the driving spring to discharge the drug from the syringe barrel.

[0124] In another aspect of the invention, the syringe comprises a movement prohibition mechanism. The movement prohibition mechanism includes the following. A latch mechanism at least part of which is housed in the cavity inside the driving spring. The latch mechanism includes at least one fitting portion configured to fit releasably onto the plunger rod and is configured to move in the tip direction of the syringe by the action of the driving spring. ○ A storage cylinder fitted into the latch mechanism. ○ The latch mechanism is configured to move from a movement prohibition position to a movement permission position with respect to the storage cylinder. - At the movement prohibited position, the storage cylinder keeps the fitting part of the latch mechanism in a state of being fitted to the plunger, so that the extension of the driving spring moves the latch mechanism and the storage cylinder to discharge the medicine from the syringe barrel. - At the movement permitted position, the storage cylinder does not keep the fitting part in a state of being fitted to the plunger.

[0125] In another aspect of the invention, at least a part of the forward spring is housed in the cavity inside the driving spring. In yet another aspect of the invention, when the forward spring is in a compressed state, its entirety is housed in the cavity inside the driving spring.

[0126] In another aspect of the invention, the starting mechanism is configured as follows. After the forward spring extends a predetermined distance in the tip direction, the driving spring is released. If necessary, the predetermined distance is between 10 mm and 20 mm, for example 18 mm.

[0127] Figure 14 shows a method for assembling a syringe equipped with a power pack. The method will be described below.

[0128] In step 101, a housing having a long axis is provided. In step 103, a driving spring is installed inside the housing. The driving spring has a tip and a base end on the opposite side of the tip along the long axis of the housing. The driving spring forms a cavity inside. In steps 105 and 107, at least a part of the plunger is installed in the medicine container, and a plunger rod is fitted into the plunger. In step 109, a latch mechanism is fitted into a storage cylinder to form a movement prohibition mechanism. The latch mechanism has at least one fitting portion. In step 111, at least a part of the latch mechanism is installed in the cavity of the driving spring, and the fitting portion is releasably fitted to the plunger. In step 113, by arranging the storage cylinder in the movement prohibition mechanism, the fitting portion is kept in a state of being fitted to the plunger. The elongation of the driving spring moves the latch mechanism and the storage cylinder in the tip direction, discharging the medicine from the syringe barrel. The storage cylinder is configured to move from a movement prohibition position to a movement permission position. At the movement permission position, the storage cylinder does not keep the fitting portion in a state of being fitted to the plunger. In some cases, in step 115, the tip and the base end of the driving spring may be compressed to put the driving spring in a compressed state, and the latch mechanism may be configured to keep the driving spring in the compressed state. It will be understood by the reader that the above steps can be executed in any order.

[0129] As described above, the syringe related to the first aspect of the invention disclosed in this specification has been described. However, the embodiments of the invention can also be said to relate to a power pack for a syringe or a power pack for a driving device of a syringe. The power pack according to the invention disclosed in this specification may be incorporated into a syringe configured to automatically advance a medicine container with a needle to an injection position and automatically discharge a single dose of medicine. In particular, the power pack may be used for the following types of auto-injectors. The auto-injector advances the medicine container to discharge a single dose of medicine and automatically retracts the medicine container relative to the housing after use.

[0130] The power packs described in this specification may be combined with one or more braking mechanisms, connection devices, and passive safety shields. Each will be described in more detail below.

[0131] [Braking mechanism] The invention disclosed in this specification also provides an example of a braking mechanism configured to weaken the force of the drive device of a syringe. The braking mechanism according to that invention will be described below in combination with the above example of the drive device. However, it will be understood that the braking mechanism does not have to be used together with the above drive device. On the contrary, the following braking mechanism can also be incorporated into other syringes having a drive device that, although different from the above drive device, needs to or would advantageously weaken at least a part of the power.

[0132] The syringes of FIGS. 1 and 2 can be equipped with the following braking mechanism. This braking mechanism is configured to weaken at least a part of the initial power of the driving spring when the syringe is activated to perform an injection.

[0133] Generally speaking, the braking mechanism includes a damper, and the damper is configured to be press-fitted to the first component of the drive device. The drive device is configured to transmit power from the driving spring to the plunger installed in the medicine container, so as to cause the driving spring to perform an injection for the user. As will be described in more detail below with reference to FIGS. 15-28, the damper and the component of the drive device into which it is fitted (hereinafter collectively referred to as the "first drive component") can be in various different forms. The damper is described in connection with many examples of the syringes described in this specification, but it will be understood that it may also be incorporated into other syringes.

[0134] FIG. 15 is an enlarged cross-sectional view of the proximal end portion of the syringe 1001 shown in FIGS. 1 and 2. This enlarged view shows the drive device 1016 of FIG. 1 together with the handle 1003, but it is separated from the rest of the syringe 1001 shown in FIG. 1.

[0135] The drive device 1016 (see FIG. 1) includes a power pack 1030, a housing (previously referred to as the proximal housing 1032), and an actuator 1034. The structures and operations of these components will be described in more detail with reference to FIGS. 3A - 14, but briefly, the power pack 1030 includes a drive spring 1017 and the movement prohibition mechanism 1036 (described above with reference to FIGS. 3 - 10). The movement prohibition mechanism 1036 is configured to couple the drive spring 1017 to the plunger rod 1015. The movement prohibition mechanism 1036 includes a latch 1040 configured to fit onto the plunger rod 1015 and the actuator 1034, and an overhang portion 1042 configured to fit onto the drive spring 1017. The overhang portion 1042 is coupled to the latch 1040 and thereby coupled to the plunger rod 1015. In this way, the drive spring 1017 is configured to transmit power to the plunger rod 1015 through the latch 1040 and the overhang portion 1042.

[0136] As shown in FIG. 15, the drive device 1016 also includes a braking mechanism. The braking mechanism is configured to weaken the initial force of the drive spring 1017 when the drive spring 1017 is released from the stored state shown in FIG. 15.

[0137] The braking mechanism according to the invention disclosed in this specification includes a damper 1200. The damper 1200 is fixed to the housing 1032 and is configured to be press - fitted onto the surface of the first drive component. The first drive component is configured to move in the longitudinal axis direction relative to the proximal housing 1032 during injection. In the embodiment described below, the first drive component is formed as a hollow plunger rod 1015.

[0138] The damper 1200 can be fixed by a pin 1202 inside the housing 1032 of the syringe 1001. Throughout the disclosure of this specification, the housing to which the damper is fixed is a housing inside the syringe, such as the proximal housing 1032 of the syringe 1001. Additionally, the damper 1200 may be fixed to a housing outside the syringe, such as the handle 1003. When the damper 1200 is fixed inside the housing of the syringe, when the driving spring 1017 is released at the start of injection, the driving components will surely move relative to the damper 1200.

[0139] The pin 1202 extends along the long axis L of the housing and includes a head and a shaft. The shaft extends through the hole 1204 in the proximal housing 1032. When the head of the pin 1202 contacts the shoulder surrounding the edge of the hole 1204 in the proximal housing 1032, it forms a stopper. This stopper fixes the pin 1202 so that it does not move in the direction of the long axis relative to the proximal housing 1032. The pin 1202 includes a screw on the shaft. This screw is configured to engage with the screw hole at the proximal end of the damper 1200 (see Fig. 16c) to fix the pin 1202 to the damper 1200, thereby fixing the damper 1200 inside the housing of the syringe 1001. The pin 1202 may be manufactured from plastite (registered trademark) or other suitably rigid material to fix the damper 1200 in place.

[0140] The embodiments described below show that the pin fixes the damper in place, but it will be understood that the fixture may have a different form from the pin. For example, the fixture may be a flange of the housing that forms a stopper for the corresponding part of the damper, an adhesive that attaches the damper to the housing, and / or a mechanical locking mechanism disposed between a part of the damper and a part of the housing. The mechanical locking mechanism includes, for example, a rotary lock and a snap lock. Additionally, the damper may be integrally formed with the proximal housing (or handle). In this case, the fixture is not required.

[0141] The damper 1200 is disposed coaxially with the first driving component within the proximal housing 1032. The damper 1200 is also disposed coaxially with the latch 1040, the overhang portion 1042, and the pin 1202 about its long axis L.

[0142] When the syringe 1001 is in the stored state (as shown in FIG. 15), the damper 1200 is installed within the longitudinal hole 1206 formed in the plunger rod 1015. The plunger rod 1015 has a substantially tubular structure and includes a substantially cylindrical enclosure. The hollow portion of this enclosure accommodates the damper 1200 as the longitudinal hole 1206. The longitudinal hole 1206 is partitioned by an inner wall 1208 and is configured (in terms of size, shape, and position) to accommodate at least a portion of the damper 1200 through an opening 1210.

[0143] Only the proximal end portion of the plunger rod 1015 is shown in FIG. 15. A connection portion 1212 can be seen at the tip of the shown portion. The connection portion 1212 is configured to be connected to the distal end portion of the plunger rod 1015 (see FIG. 1). Although the plunger rod 1015 shown in this specification includes a plurality of components, it will be understood that the plunger rod 1015 may be an integrally formed product including a hollow portion at the proximal end.

[0144] As shown in FIG. 15, the damper 1200 includes a braking member 1214. The braking member 1214 is configured to be press-fitted onto the inner wall 1208 of the plunger rod 1015 while the plunger rod 1015 moves relative to the damper 1200. The braking member 1214 has a maximum outer diameter wider than the maximum outer diameter of the main body of the damper 1200.

[0145] The braking member 1214 is formed as a strip or ring of an elastically deformable material and is configured to contact at least a part of the inner wall 1208 of the longitudinal hole 1206 during injection. The maximum outer diameter of the braking member 1214 is wider than the minimum inner diameter of the longitudinal hole 1206. The inner diameter of the longitudinal hole 1206 may be constant in its longitudinal direction (in this case, the inner diameter of the longitudinal hole 1206 is always narrower than the outer diameter of the braking member 1214 before deformation), or it may vary (in this case, the inner diameter of the longitudinal hole 1206 is narrower than the outer diameter of the braking member 1214 only in a part in the longitudinal direction of the longitudinal hole 1206). This will be understood.

[0146] Since the inner diameter of at least a part of the longitudinal hole 1206 is surely narrower than the outer diameter of the braking member 1214, during at least a part of the injection period, the deformable material of the braking member 1214 is crushed against the inner wall 1208 of the longitudinal hole 1206. Due to this crushing, an interference fit is formed between the damper 1200 and the plunger rod 1015, so that even when the driving spring 1017 acts, it is difficult for the plunger rod 1015 to move toward the proximal side with respect to the damper 1200 (however, it is not impossible to move).

[0147] Due to the interference fit between the damper 1200 and the first driving component (here, the plunger rod 1015), the frictional force between the damper 1200 and the plunger rod 1015 resists the force of the driving spring 1017, so that the force of the driving spring 1017 is weakened in at least a part of the section where the driving spring 1017 extends.

[0148] Hereinafter, the damper 1200 will be described in more detail with reference to FIGS. 16a - 16c, and the plunger rod 1015 will be described in more detail with reference to FIGS. 17a and 17b.

[0149] The interaction between the damper 1200 and the plunger rod 1015 along the orbit of the plunger rod 1015 will be described in more detail with reference to FIGS. 18a - 18e and FIG. 19.

[0150] FIG. 16a is an isometric view of the damper 1200 of FIG. 15, and FIG. 16b is an enlarged view thereof. FIG. 16c shows a cross-section of the damper 1200 taken along a plane along the major axis L shown in FIG. 15.

[0151] As shown in FIGS. 16a and 16b, the damper 1200 includes an elongated body 1200a and a deformable braking member 1214. The braking member 1214 surrounds the head 1200b of the damper 1200. In this sense, the damper 1200 can also be said to be a mandrel. The body 1200a can be manufactured from nylon (registered trademark) resin or other suitably rigid materials. The braking member 1214 can be manufactured from silicone or other elastomer or elastically deformable materials.

[0152] As shown in FIGS. 16a and 16b, the body 1200a of the damper 1200 includes a positioning portion 1216 at the proximal end. The positioning portion 1216 is for placing the proximal end of the damper 1200 into the groove of the proximal housing 1032. In the illustrated embodiment, the positioning portion 1216 has a hexagonal prism. This prism is for placing one end of the damper 1200 into the hexagonal seat of the proximal housing 1032 shown in FIG. 15. The positioning portion 1216 includes an annular flange on the tip side of the proximal end of the damper 1200. This flange is provided with a surface for coupling to the shoulder surrounding the seat of the proximal housing 1032. The positioning portion 1216 and the flange make it easier to place the damper 1200 into the proximal housing 1032 and align it with the major axis L during the assembly of the syringe 1001.

[0153] The head 1200b is located at the tip of the damper 1200 or on the way thereto. The head 1200b and the positioning portion 1216 are connected by a shaft extending between them. As seen in FIG. 16b, the head 1200b has a larger diameter than either the elongated body 1200a of the shaft or the positioning portion 1216.

[0154] The head 1200b of the damper 1200 supports the braking member 1214. By installing the braking member 1214 at the tip of the damper 1200, the distance that the braking member 1214 moves while being fitted into the inner wall 1208 of the longitudinal hole 1206 of the plunger rod 1015 can be maximized.

[0155] As described above, an elastic deformable material band surrounding the head 1200b (or a part thereof) of the damper 1200 can be attached to the braking member 1214. The braking member 1214 may be overmolded on the head 1200b of the damper 1200.

[0156] In the configuration shown in FIG. 16b, the head 1200b includes two circumferential grooves 1218a, 1218b that are spaced apart in the longitudinal direction thereof. A circumferential ridge 1220 is formed between these grooves 1218a, 1218b. Although two grooves 1218a, 1218b are shown, the number of grooves included in the head 1200b may be any number, such as one, three, four, etc.

[0157] As shown in FIGS. 16a, 16b, and 16c, the braking member 1214 includes an annular cylinder. Since the inner peripheral surface of this cylinder has a contour that matches the outer peripheral surface contour of the head 1200b of the damper 1200, it fits precisely into the circumferential grooves 1218a, 1218b and on the circumferential ridge 1220. The contour of the inner peripheral surface of this cylinder is a portion that is supplemented if necessary to fit the braking member 1214 onto the head 1200b and stably mount it around. With this configuration, even when a shearing force associated with friction acts on the braking member 1214 in any direction parallel to the major axis L, the head 1200b can hold the braking member 1214 in place. In FIG. 16c, the state where the braking member 1214 and the head 1200b are fitted to each other can be seen more clearly. FIG. 16c is a cross-sectional view of the braking member 1214 mounted in the grooves 1218a, 1218b and on the ridge 1220 of the head 1200b. Since the inner peripheral surface of the braking member 1214 has a contour that matches the contours of the grooves 1218a, 1218b and the ridge 1220 that form the surface of the head 1200b, it fits securely and precisely into them.

[0158] As shown in FIGS. 16b and 16c, the braking member 1214 includes grooves 1222 extending along the outer peripheral surface. These grooves 1222 form two bands 1224a, 1224b that extend circumferentially on the outer peripheral surface of the braking member 1214 (see FIG. 16a). Since the outer diameters C1 of the bands 1224a, 1224b are larger than the outer diameter C2 of the head 1200b of the damper 1200, the bands 1224a, 1224b project to the farthest from the axis of the damper 1200 and are configured to fit into the inner wall 1208 of the longitudinal hole 1206 of the plunger rod 1015 in the damper 1200. The only parts of the damper 1200 that can fit into the inner wall 1208 of the longitudinal hole 1206 are the braking member 1214 and the head 1200b. As a result, no matter where the plunger rod 1015 is in the syringe 1001, the damper 1200 only fits onto a part of the inner wall 1208, so the friction between the damper 1200 and the plunger rod 1015 is better controlled.

[0159] Figure 16c is a cross-sectional view of the damper 1200. As shown in Figure 16c, the damper 1200 has a hole 1226. The hole 1226 will be described in more detail below. The hole 1226 is configured to accommodate a pin 1202 (shown in Figure 15) that fixes the damper 1200 inside the housing. The damper 1200 also includes a socket 1228. The socket 1228 is hexagonal if necessary and is configured to receive the head of a tool (such as a hex wrench) for attaching the pin 1202 to the damper 1200. Although the pin may be fixed to the damper without using a socket configured to receive a tool, the above configuration would be more convenient. This is because the position of the braking member 1214 and the position of the damper 1200 within the elongated proximal housing 1032 make the outer surface of the damper 1200 difficult to grasp.

[0160] In the manufacture of the damper 1200 of Figures 16a, 16b, and 16c, the braking member 1214 can be overmolded onto the head 1200b. This strengthens the mechanical connection between the braking member 1214 and the main body 1200a of the damper 1200 more than other means (such as installing an O-ring in a groove), which helps to securely attach the braking member 1214 to the main body 1200a. Thereby, variations in the performance of the damper can be suppressed, and the manufacturing and / or assembly costs can be reduced, for example, by suppressing the need for quality control or by simplifying quality control.

[0161] In the configuration shown in Figures 16a - 16c, the grooves 1218a, 1218b and the ridge 1220 of the damper 1200 extend circumferentially around the head 1200b to form a continuous annulus without breaks. Thus, the braking member 1214 includes a continuous ring whose inner circumferential contour matches the outer circumferential contour of the head 1200b of the damper 1200. However, it will be understood that this configuration may be changed such that the annulus formed by the grooves 1218a, 1218b, and / or the ridge 1220 includes breaks, and accordingly, the inner circumferential surface of the braking member 1214 may also be changed.

[0162] Furthermore, in the illustrated embodiment, there are two circumferential grooves included in the damper 1200, and there is one circumferential ridge formed therebetween. However, those skilled in the art will understand that other configurations are possible. For example, three circumferential grooves may be provided, and circumferential ridges may be provided to separate every two adjacent grooves. Further, only one circumferential groove may be provided, and a part of the braking member may be installed therein.

[0163] As understood, the damper 1200 is fixed in the housing of the syringe 1001 by an interference fit between the plunger rod 1015 and the damper 1200, so that the damper 1200 can function as a brake when the driving spring 1017 moves other components relative to the housing. For that purpose, the fixture is arranged to prevent relative movement between the damper 1200 and the housing at least in a direction parallel to the long axis of the housing.

[0164] Hereinafter, the plunger rod 1015 shown in FIG. 15 will be described in more detail with reference to FIGS. 17a and 17b. FIG. 17a is an isometric view of the base end portion of the plunger rod 1015 in FIG. 15. (The complete plunger rod 1015 including the base end portion and the tip end portion is shown in FIG. 1.) FIG. 17b is a cross-sectional view of the base end portion of the plunger rod 1015 taken along a plane along the long axis L. As shown in FIG. 17a, the inner wall 1208 forms a longitudinal hole 1206. The longitudinal hole 1206 extends over the entire length of the base end portion of the plunger rod 1015. The base end portion of the plunger rod 1015 is provided with a snap-fit connection portion 1230 at the tip. This connection portion 1230 connects between the base end portion and the tip end portion of the plunger rod 1015 together with the snap-fit connector at the tip end portion of the plunger rod 1015 (shown in FIG. 1).

[0165] As shown in Fig. 17b, five portions with different inner diameters are arranged in the vertical hole 1206. Generally speaking, these five portions include a tip section 1232 with a first inner diameter d1, an intermediate section 1234 with a second inner diameter d2, and a base end section 1236 with a third inner diameter d3. Transition sections 1238 and 1240 are provided between these portions. The first transition section 1238 connects the tip section 1232 to the intermediate section 1234, and the second transition section 1240 connects the intermediate section 1234 to the base end section 1236.

[0166] As understood from Fig. 17b, since the inner diameter of the vertical hole 1206 changes along its length direction, by changing the amount of compression of the braking member 1214 while the plunger rod 1015 advances relative to the braking member 1214, the braking force applied by the damper 1200 during injection can be changed.

[0167] When the driving spring 1017 is in the stored state, the head 1200b of the damper 1200 is located in the tip section 1232 (shown in Fig. 15). When the plunger rod 1015 advances relative to the damper 1200, the braking member 1214 moves from the tip section 1232 through the intermediate section 1234 to the base end section 1236.

[0168] The inner diameter d2 of the intermediate section 1234 is smaller than either the inner diameter d1 of the tip section 1232 or the inner diameter d3 of the base section 1236. When the head 1200b of the damper 1200 is positioned within the intermediate section 1234, the braking member 1214 is compressed. As a result, the amount of compression of the braking member 1214 by the inner wall 1208 of the longitudinal hole 1206 increases, so the perpendicular resistance force between the braking member 1214 and the inner wall 1208 is strengthened. Therefore, when the driving spring 1017 moves the plunger rod 1015 relative to the damper 1200, the friction between the inner wall 1208 and the braking member 1214 is strengthened. When the braking member 1214 is positioned in the tip section 1232 of the longitudinal hole 1206 (for example, while the syringe 1001 is being stored), or when it is positioned in the base section 1236 of the longitudinal hole 1206 (for example, when the plunger rod 1015 advances and moves the medicine container to the injection position), the braking member 1214 is located in the wider portion of the longitudinal hole 1206, so the inner wall 1208 of the longitudinal hole 1206 is not compressed (or the amount of compression decreases). In this way, when the plunger rod 1015 starts moving relative to the damper 1200 and when it finishes moving, the braking force applied by the braking mechanism can be removed (or weakened). Moreover, the tip section 1232 provides a space in which the braking member 1214 can remain in an uncompressed state during storage and before use of the syringe 1001. Therefore, compared with a syringe in which the braking member is continuously compressed during the storage period, the braking function and its reliability can be improved in the syringe 1001.

[0169] By changing the diameter of each section of the longitudinal hole 1206 with respect to the outer diameter of the braking member 1214, the braking force of the damper 1200 can be changed as the plunger rod 1015 advances relative to the damper 1200. Furthermore, by changing the length and / or diameter for each of the above sections, the distance by which the force associated with the extension of the driving spring 1017 is weakened can also be changed.

[0170] In the above-described embodiment, the minimum inner diameter of the vertical hole 1206 is wider than the outer diameter of the rigid head 1200b of the damper 1200. However, the inner diameter of at least one section of the vertical hole 1206 (here, the intermediate section 1234) is equal to or less than the outer diameter of the braking member 1214 before deformation. By narrowing the inner diameter of at least a part of the plunger rod 1015 to be less than the outer diameter of the braking member 1214 before deformation, a frictional force that weakens the force of the driving spring 1017 is generated.

[0171] It will be understood that each section of the vertical hole 1206 shown in FIG. 17b may be changed. For example, in the embodiment of FIG. 17b, there is only one section (intermediate section 1234) whose inner diameter is smaller than the outer diameter of the braking member 1214. However, the inner diameters of a plurality of sections of the vertical hole 1206 may be smaller than the outer diameter of the braking member 1214. Further, in the above-described embodiment, the vertical hole 1206 is divided into five sections, but the number of sections may be more or less than these. For example, the inner diameter of the vertical hole 1206 may be substantially constant along the length direction, and when the plunger rod 1015 moves forward with respect to the damper 1200, the braking force of the damper 1200 may be substantially constant. The transition sections 1238 and 1240 may be omitted, and instead, a step may be provided between sections with different diameters. A vertical hole that gradually tapers smoothly from one end to the other end may be provided in the plunger rod. These changes and other changes will be apparent to those skilled in the art in view of the disclosure of this specification.

[0172] In an embodiment of the invention, at the initial stage of the movement of the plunger rod 1015, the damper 1200 weakens the force of the driving spring 1017. However, the period during which the damper 1200 weakens the force of the driving spring 1017 may be a period before the injection needle is inserted and / or during the period when the injection needle is inserted, and also a period during which the plunger rod 1015 moves before a large amount of medicine flows from the medicine container 1007 through the injection needle. Note that when the flow of the medicine in the injection needle is restricted, a pressure that pushes back the flow acts. Therefore, weakening the force of the driving spring 1017 by the damper 1200 may not be necessary while the medicine is being administered through the hole of the injection needle. Therefore, weakening the force of the driving spring 1017 by the damper 1200 at the initial stage of the operation of the syringe may not be necessary in a later period (for example, after the insertion of the injection needle).

[0173] Hereinafter, with reference to FIGS. 18a-18e, the interaction between the damper 1200 and the plunger rod 1015 when the plunger rod 1015 shown in FIG. 15 advances with respect to the damper 1200 will be described in more detail.

[0174] FIGS. 18a-18e are cross-sectional views of the plunger rod 1015 and the damper 1200 taken along a plane along the major axis L. FIG. 18a shows the damper 1200 in a state where the head 1200b is located in the tip section 1232 of the longitudinal hole 1206. FIGS. 18b-18e show the damper 1200 when the plunger rod 1015 advances to the position closest to the tip with respect to the damper 1200 during injection.

[0175] As shown in Fig. 18a, until injection is started (by releasing the driving spring 1017), the head 1200b of the damper 1200 is located in the distal section 1232 of the longitudinal hole 1206 together with the braking member 1214. As described above, since the inner diameter of this section 1232 is wider than the outer diameter of the braking member 1214, the braking member 1214 does not contact the inner wall 1208 of the longitudinal hole 1206 (i.e., is not compressed by the inner wall 1208) (see Figs. 17a and 17b). As a result of this arrangement, the catching of the braking member 1214 on the inner wall 1208 of the longitudinal hole 1206 is limited (or does not exist), so the frictional force between the plunger rod 1015 and the damper 1200 is weak (or has been removed).

[0176] Fig. 18b shows the position of the plunger rod 1015 relative to the damper 1200 when the head 1200b of the damper 1200 straddles the first transition section 1238 of the longitudinal hole 1206 and reaches at least a part of the intermediate section 1234. At this position, since the inner diameter of the longitudinal hole 1206 is narrower than the outer diameter of the braking member 1214 (before deformation), the base end portion of the braking member 1214 is compressed by the inner wall 1208 of the longitudinal hole 1206. On the other hand, since the tip end portion of the braking member 1214 is still located in the distal section 1232 of the longitudinal hole 1206, it is not compressed by the inner wall 1208 of the longitudinal hole 1206 (or the amount of compression is smaller than that of the base end portion). As a result, the catching of the braking member 1214 on the inner wall 1208 of the longitudinal hole 1206 increases, so the frictional force between the plunger rod 1015 and the braking member 1214 is of medium strength.

[0177] Fig. 18c shows the relative position between the damper 1200 and the plunger rod 1015 when the plunger rod 1015 of Fig. 15 further advances relative to the damper 1200 and the head 1200b of the damper 1200 is located in the intermediate section 1234 of the longitudinal hole 1206. At this position, the braking member 1214 is compressed by the inner wall 1208 of the longitudinal hole 1206 over its entire length. As a result, the frictional force between the plunger rod 1015 and the braking member 1214 due to the catching of the braking member 1214 on the inner wall 1208 of the longitudinal hole 1206 is strong.

[0178] As shown in FIG. 18d, when the plunger rod 1015 continues to move toward the tip side with respect to the damper 1200, a part of the head 1200b of the damper 1200 is located in the intermediate section 1234 of the vertical hole 1206 (where the braking member is compressed), and another part straddles the second transition section 1240 and is located in the base end section 1236 (where the braking member is not compressed or the amount of compression is small). At this position, as in the position shown in FIG. 18b, only the tip of the braking member 1214 remains in the narrower intermediate section 1234, so only a part of the braking member 1214 is compressed. As a result, the frictional force between the plunger rod 1015 and the braking member 1214 due to the catching of a part of the braking member 1214 on the inner wall 1208 of the vertical hole 1206 returns to a medium strength.

[0179] Finally, referring to FIG. 18e, when the plunger rod 1015 reaches the position closest to the tip with respect to the damper 1200, the head 1200b of the damper 1200 is located in the base end section 1236 of the vertical hole 1206. Since the inner diameter of the base end section 1236 of the vertical hole 1206 is larger than the outer diameter of the braking member 1214, the braking member 1214 is not compressed by the inner wall 1208 of the vertical hole 1206. As a result, the catching of the braking member 1214 on the inner wall 1208 of the vertical hole 1206 is limited (or does not exist), so the frictional force between the plunger rod 1015 and the damper 1200 is weak (or removed).

[0180] Considering the above, the tip section 1232 of the vertical hole 1206 may be referred to as the "damper storage area". When disposed in this area, the braking member 1214 is in an uncompressed state (see Fig. 18a). The state where the damper 1200 is at this position relative to the plunger rod 1015 corresponds to the storage state of the syringe. In this state, the syringe 1001 is before activation, and the driving spring 1017 is compressed. The tip section 1232 of the vertical hole 1206 is configured to accommodate the head 1200b of the damper 1200 so that the damper 1200 and the plunger rod 1015 are hardly or not caught at all. This configuration would be convenient. When assembling the syringe 1001, when inserting the damper 1200 into the tip of the plunger rod 1015 to assemble the braking mechanism, it is not necessary to overcome the strong friction associated with the catch between the braking member 1214 and the plunger rod 1015.

[0181] The intermediate section 1234 may be referred to as the "damper compression area". When disposed in this area, the braking member 1214 is in a compressed state. At this stage, since the braking member 1214 is compressed to the maximum, the force of the driving spring 1017 immediately after the activation of the syringe is weakened. Thereby, the impact that the medicine container exerts on the components inside the syringe can be minimized. Separately or in addition thereto, it is possible to avoid a strong impact that startles the user or vibrations that cause an unexpected mistake by the user.

[0182] The base end section 1236 may be referred to as the "non-braking area". When disposed in this area, the braking member 1214 is almost or completely disengaged from the compressed state. It would be convenient to provide the non-braking area at the base end of the vertical hole 1206. This is because the force of the driving spring 1017 is only weakened in the section of the orbit of the driving spring 1017 where the force is the strongest and the medicine container 1007 is advanced to the injection position (for example, the initial section of the movement). Further, (if necessary, a tapered transition section may be provided between the base end section 1236 and the intermediate section 1234 and) the base end section may be expanded. This is because it is convenient for retracting the plunger rod 1015 relative to the damper 1200 after the completion of the injection.

[0183] The plunger rod 1015 shown in FIGS. 15-18e has a longitudinal hole 1206 with a varying inner diameter, but it will be understood that the inner diameter of this longitudinal hole may be substantially constant. In this longitudinal hole, the braking member 1214 catches on the inner wall of the longitudinal hole over substantially the entire length of the section where the plunger rod 1015 moves relative to the damper 1200. Although an example of such an embodiment is not shown in the drawings, it will be understood that simply replacing the plunger rod 1015 shown in FIGS. 18a-18e with a plunger rod having a substantially cylindrical hole with a constant inner diameter would suffice.

[0184] As will be described below with reference to FIG. 19, other configurations in which the damper is housed within a hollow plunger rod are also disclosed.

[0185] FIG. 19 is a cross-sectional view of a further embodiment of the invention disclosed in this specification. The embodiment shown in FIG. 19 is similar to the above-described embodiment. As can be seen in FIG. 19, the syringe 4001 includes a drive device 4016. The drive device 4016 includes a proximal housing 4032, and the proximal housing 4032 houses a drive spring 4017, a latch 4040, an overhang 4042, and an activator 4034. Similar to the above-described embodiment, both the latch 4040 and the overhang 4042 transmit power from the drive spring 4017 to the plunger rod 4015. The plunger rod 4015 includes a longitudinal hole 4206, i.e., a hollow portion, at its proximal end.

[0186] Unlike the embodiment described with reference to FIG. 15, the first drive component 4015 in the embodiment of FIG. 19 has two portions with different inner diameters, a distal portion 4232 and a proximal portion 4236. They are configured to house the damper 2400 according to the extended state of the plunger rod 4015. The second inner diameter of the proximal portion 4236 is wider than the first inner diameter of the distal portion 4232.

[0187] The damper 4200 in FIG. 19 is also different from the damper 1200 in FIG. 15. The damper 1200 in FIG. 15 includes only one braking member 1214 configured such that the contour of the inner peripheral surface matches the contour of the outer peripheral surface of the head 1200b. On the other hand, the damper 4200 in FIG. 19 includes a plurality of annular grooves in the head 4200b, and each groove is configured to accommodate one O-ring therein. The damper 4200 also includes a main body portion 4200a that supports the head 4200b.

[0188] Three circumferential grooves 4218a, 4218b, 4218c are provided in the head 4200b of the damper 4200 shown in FIG. 19. Three braking members 4214a, 4214b, 4214c (each formed as one O-ring) are separately installed in the circumferential grooves 4218a, 4218b, 4218c one by one. When the head 4200b is correctly placed, the outer diameters of the braking members 4214a, 4214b, 4214c are wider than the outer diameter of the head 4200b.

[0189] The damper 4200 in FIG. 19 operates in the same manner as the damper 1200 in FIG. 15. At the position shown in FIG. 19, since the inner diameter of the tip portion 4232 of the vertical hole 4206 is narrower than the outer diameters of the braking members 4214a, 4214b, 4214c of the damper 4200, the braking members 4214a, 4214b, 4214c are compressed by the inner wall 4208 of the vertical hole 4206. As a result, a strong frictional force is generated between the plunger rod 4015 and the damper 4200 due to the engagement of the braking members 4214a, 4214b, 4214c with the inner wall 4208 of the vertical hole 4206.

[0190] When the braking members 4214a, 4214b, 4214c are installed in the base end portion 4236 of the vertical hole 4206, since the base end portion 4236 has a large diameter, the braking members 4214a, 4214b, 4214c are no longer compressed (or the amount of compression is small). As a result, the engagement of the braking members 4214a, 4214b, 4214c with the inner wall 4208 of the vertical hole 4206 is restricted (or does not exist), so the frictional force between the plunger rod 4015 and the damper 4200 is weak (or removed).

[0191] A feature of the plunger rod 4015 of FIG. 19 not seen in the embodiment of FIG. 15 is the plug 4242. The plug 4242 is in the form of a cap that closes the longitudinal hole 4206 at the tip of the tip portion 4232 of the longitudinal hole 4206. The plug 4242 forms a surface adjacent to the end of the head 4200b of the damper 4200 during the assembly of the syringe, and prevents the first drive component 4015 from retreating too far when one injection is completed and the first drive component 4015 returns to its original position. It will be understood that the plug 4242 may be omitted from this embodiment or, if necessary, added to the embodiment of FIG. 15. The plug 4242 also helps to prevent the damper 4200 from interfering with other components of the syringe, such as a PCB or the like disposed between the damper and the plunger.

[0192] It will be understood that the damper and the plunger rod are not limited to the types shown in FIGS. 15 and 19, i.e., those in which the damper catches on the inner wall of the longitudinal hole provided in the plunger rod. According to the invention disclosed in this specification, it is also possible to configure the damper to catch on other drive components.

[0193] The power pack is also not limited to that shown in FIGS. 15 and 19, and a member similar to the overhang of the latch may directly transmit the force of the driving spring to the first drive component without using the latch. This modification and other modifications will become apparent from the following description with respect to FIGS. 20 - 28d.

[0194] FIG. 20 is a cross-sectional view of an embodiment of the invention. In this embodiment, the damper 5200 is configured to directly catch on a component (other than the plunger rod) of the drive device. FIG. 20 shows a configuration similar to the configurations shown in FIGS. 15 and 19. In this configuration, the drive device includes a driving spring 5017 and a damper 5200. The damper 5200 is configured to weaken at least the initial elongation of the driving spring 5017.

[0195] Unlike the embodiment described with reference to FIG. 15, the damper 5200 of the embodiment of FIG. 20 does not have an enlarged head. More specifically, the body of the damper 5200 shown in FIG. 20 is a rod having a substantially uniform diameter over substantially its entire length. However, there are two circumferential grooves 5218a, 5218b around the tip of the damper 5200. The grooves 5218a, 5218b each accommodate one braking member 5214a, 5214b. The two braking members 5214a, 5214b have the same shape as the O-ring described with reference to FIG. 19.

[0196] Unlike the embodiment described with reference to FIG. 15, the drive component in which the damper 5200 is fitted is the sleeve 5015. Since the sleeve 5015 is coupled to the drive spring 5017, it functions as a first drive component moved by the drive spring 5017. The sleeve 5015 may form part of the plunger rod of the syringe.

[0197] The sleeve 5015 has a single longitudinal hole. This longitudinal hole is somewhat similar to the longitudinal hole of the above-described plunger rod and is configured to accommodate the damper 5200. The inner wall of the longitudinal hole is configured such that the damper 5200 is press-fitted.

[0198] As seen in FIG. 20, the longitudinal hole of the sleeve 5015 has three sections. A tip section 5232 of the first diameter, a base section 5236 of the second diameter wider than the first diameter, and a tapered transition section 5238 sandwiched between the tip section 5232 and the base section 5236. Similar to the above-described embodiment, in the sleeve 5015, the inner diameter of at least one section is narrower than the outer diameter of the braking members 5214a, 5214b. In the shown embodiment, since the inner diameter of the tip section 5232 is wider than the outer diameter of the braking members 5214a, 5214b, the tip section 5232 can be called a damper storage area. Since the inner diameter of the base section 5236 is narrower than the outer diameter of the braking members 5214a, 5214b, the base section 5236 can be called a damper compression area.

[0199] Unlike the first drive component shown in FIGS. 15 and 19, the drive component (sleeve 5015 in this embodiment) is not coupled to the drive spring 5017 via a latch mechanism. Instead, the first drive component fits into a drive sleeve 5042 that has the same shape as the overhang portion 1042 of the latch mechanism described above. The drive sleeve 5042 (similar in shape to the overhang portion 1042) has a tip-side flange 5072, which is pressed against the drive spring 5017. Since the sleeve 5015 fits into the drive sleeve 5042, when the drive sleeve 5042 moves in the tip direction due to the action of the drive spring 5017, the sleeve 5015 moves in the tip direction together with the drive sleeve 5042.

[0200] Sleeve 5015 and / or the drive sleeve 5042 may be configured to transmit power to a plunger rod (not shown). The plunger rod is configured to move the plunger in the tip direction within the medicine container to discharge one dose of medicine. Therefore, the tip of the sleeve 5015 may include a positioning member (for example, an annular flange that is one step higher), which may be fitted to a corresponding member at the proximal end of the plunger rod.

[0201] The above embodiment includes a longitudinal hole whose inner diameter changes along the length direction. Thereby, as the drive spring extends, the compression amount (and thus the braking force) of the braking member can be changed. However, it will be understood that the inner diameter may be constant along the length direction of the longitudinal hole. Thereby, even when the longitudinal hole moves toward the tip side with respect to the damper, the braking force remains substantially constant.

[0202] Turning to FIG. 21, another embodiment of the invention disclosed in this specification will be described. FIG. 21 shows a plunger rod 6015. The plunger rod 6015 has a plurality of grooves 6250a, 6250b, 6250c extending in a direction substantially along the major axis. These grooves 6250a, 6250b, 6250c may be along the major axis, that is, parallel to the major axis. As will be described in more detail below, the grooves 6250a, 6250b, 6250c reduce the surface area of the wall of the longitudinal hole that contacts the braking member. In the space thus formed, the braking member can be deformed so as to weaken the compressive force received from the wall of the longitudinal hole. Therefore, the frictional force between the damper and the first driving component is weakened in the surface area of the first driving component in which the damper is fitted.

[0203] FIG. 21 is in particular a cross-sectional view of a modified example 7015 of the plunger rod of FIGS. 17a and 17b. FIG. 22a is a cross-sectional view taken along line A-A' of FIG. 21. FIG. 22b is a cross-sectional view taken along line B-B' of FIG. 21. FIG. 22c is a cross-sectional view taken along line C-C' of FIG. 21. FIG. 22d is a cross-sectional view taken along line D-D' of FIG. 21.

[0204] Figure 21 shows essentially the same as the first driving component shown in FIGS. 17a and 17b, but is different in the following points. As shown in FIG. 21, the intermediate section 6234 of the longitudinal hole 6206 (located between the tip section 6232 and the base section 6236) includes a plurality of grooves 6250a, 6250b, 6250c on the inner surface. The grooves 6250a, 6250b, 6250c extend parallel to the major axis L of the plunger rod 6015. Each of the grooves 6250a, 6250b, 6250c extends in the direction of the major axis L from the base to the tip of the intermediate section 6234. The first groove 6250a extends over substantially the entire intermediate section 6234 and has a termination before the tip of the intermediate section 6234. The second groove 6250b is circumferentially separated from the first groove 6250a and has a length that is approximately 2 / 3 of the length of the intermediate section 6234. The third groove 6250c is circumferentially separated from both the first groove 6250a and the second groove 6250b and has a length that is approximately 1 / 2 of the length of the intermediate section 6234. The first groove 6250a, the second groove 6250b, and the third groove 6250c are arranged in the following order on the circumference of the intermediate section 6234: the first groove, the second groove, the third groove, the second groove, the first groove, the first groove, the second groove, the third groove, the second groove, the first groove.

[0205] As shown in FIG. 22a, the first cross-section A-A' of the plunger rod 6015 in FIG. 21 is between the tip of the intermediate section 6234 and the end of the first groove 6250a and does not include any of the grooves 6250a, 6250b, 6250c. As shown in FIG. 22b, the second cross-section B-B' of the plunger rod 6015 in FIG. 21 is between the end of the first groove 6250a and the end of the second groove 6250b and includes only the first groove 6250a. As shown in FIG. 22c, the third cross-section C-C' of the plunger rod 6015 in FIG. 21 is between the end of the second groove 6250b and the end of the third groove 6250c and includes only the first groove 6250a and the second groove 6250b. As shown in FIG. 22d, the fourth cross-section D-D' of the plunger rod 6015 in FIG. 21 is between the end of the third groove 6250c and the base of the intermediate section 6234 and includes all of the first groove 6250a, the second groove 6250b, and the third groove 6250c.

[0206] Thus, as the distance from the tip to the base end of the intermediate section 6234 increases, the number of grooves 6250a, 6250b, 6250c per unit circumference of the intermediate section 6234 increases. Therefore, within the intermediate section 6234, as the plunger rod 6015 advances and the damper's braking member moves from the tip to the base end of the intermediate portion 6234, the surface area of the plunger rod 6015 that contacts the braking member decreases. As a result, as the plunger rod 6015 advances, the contact area between the damper and the inner wall of the plunger rod 6015 decreases. In other words, the proportion of the inner wall to the groove decreases towards the base end. Therefore, as the plunger rod 6015 advances, the frictional force between the damper and the plunger rod 6015 weakens step by step.

[0207] In the embodiment shown in FIG. 21, there are 10 grooves in the intermediate portion. However, it will be understood that the total number of grooves, as well as the number of grooves for different lengths, can be changed. Further, in this embodiment, it is described that grooves are provided in a driving component whose inner diameter changes along the longitudinal direction, but grooves may be provided in something other than this configuration.

[0208] Although this embodiment is described with respect to the plunger rod, it will be understood that the above grooves may be incorporated into the sleeve 5015 of FIG. 20, or may be incorporated into other driving components configured to move relative to the damper. Further, in the above description, the grooves are on the inner wall of the plunger rod, but the embodiment is not limited thereto. For example, as described in the following part of this specification, when the damper is annular (see, for example, FIG. 27), and a first driving component is disposed inside the damper, grooves may be formed on the outer peripheral surface of the first driving component arranged to catch on the damper. Separately from or in addition to that, there may be grooves in the portion of the damper arranged to fit onto the first driving component.

[0209] Next, turning to FIGS. 23-24b, the braking mechanism according to the invention disclosed in this specification may include a damper having a plurality of deformable elongated plate-like members (splines or ridges). The splines extend in the longitudinal direction of the damper (i.e., substantially parallel to the long axis of the syringe) and are arranged to be compressed by a first driving component such as a plunger rod or other components of the driving device. The first driving component may include a compression ring configured to compress the splines. As can be understood from the disclosure of this specification, it is possible to control the strength of the frictional force between the damper and the first driving component by using the splines provided on the portion of the damper arranged to fit onto the first driving component. Similar to the above-described grooves, the friction between the damper and the first driving component may be increased or decreased by changing the length, width, or thickness of the splines, or by changing the number of splines per unit circumference.

[0210] More specifically, as shown in FIG. 23, some embodiments include a damper 7200 arranged coaxially with the first driving component. In this embodiment, the first driving component is in the form of a sleeve 7015 similar to the sleeve 5015 of FIG. 19. Similar to the embodiment shown in FIG. 19, the sleeve 7015 is coupled to a driving sleeve 7252. The driving sleeve 7252 is provided with a tip-side flange 7072 against which a driving spring 7017 can be compressed. As in the embodiment shown in FIG. 20, the damper 7200 is fixed in the housing by a pin 7202. The pin 7202 is fastened to the damper 7200.

[0211] As shown in FIG. 23, the sleeve 7015 includes a longitudinal hole 7206. The longitudinal hole 7206 is configured to accommodate at least a part of the damper 7200. The sleeve 7015 also includes a compression ring 7254 at or near the proximal end of the longitudinal hole 7206. The compression ring 7254 is made of a material (such as metal) that does not deform under the force received from the damper 7200 when the sleeve 7015 advances relative to the damper 7200 during injection. The compression ring 7254 is located at the proximal end of the sleeve 7015 and occupies only a part of the longitudinal direction of the sleeve 7015.

[0212] The damper 7200 has a plurality of splines 7256 extending in the direction of the major axis on its outer surface. The splines 7256 extend from the tip of the damper 7200 over a part of its body in the direction of the major axis. The splines 7256 protrude radially from the outer peripheral surface of the body of the damper 7200 and are arranged at intervals around its body. Due to the splines 7256 extending in the outer peripheral direction, the diameter of the damper 7200 is larger than the diameter of the cylindrical rod located at the tip of the damper 7200. This diameter (the "spline diameter") is also wider than the minimum inner diameter of the compression ring 7254.

[0213] Except for the proximal end, the splines 7256 have substantially constant height in the longitudinal direction and are inclined so as to approach the body of the damper 7200 as they approach the proximal end. The outer diameter of the splines 7256 is wider than the minimum inner diameter of the compression ring 7254. Since at least the splines 7256 of the damper 7200 are formed of an elastically deformable material, the splines 7256 can be compressed by the inner surface of the compression ring 7254. The splines 7256 may be formed of an elastomer, such as a thermoplastic elastomer.

[0214] As shown in FIG. 23, one end of the compression ring 7254 is inclined from a diameter wider than the spline diameter to a diameter narrower than the spline diameter. As a result, the compression ring 7254 divides the vertical hole 7206 into a damper storage area at the tip side of the compression ring 7254, a damper compression area formed by the compression ring 7254, and a non-braking area at the base end side of the compression ring 7254. The inner diameter of the vertical hole 7206 may be constant and wider than the outer diameter of the spline 7256 extending along the body of the damper 7200 (regardless of the position relative to the compression ring 7254). The spline 7256 in FIG. 23 is clearly visible in FIG. 24a (perspective view of the damper in FIG. 23).

[0215] Referring further to FIG. 23, when the syringe is in the storage state (the driving spring is fully compressed), the sleeve 7015 is in a position where it has fully retracted relative to the damper 7200, and the damper storage area at the tip accommodates the portion of the damper 7200 including the spline 7256. Since the outer diameter of the spline 7256 is narrower than the inner diameter of the sleeve 7015 and the outer diameter of the body of the damper 7200 is narrower than the minimum inner diameter of the compression ring 7254, the damper 7200 and the inner wall of the first driving component 7015 do not get caught.

[0216] During the operation of the syringe, when the first driving component 7015 advances relative to the damper 7200 by the force of the driving spring 7017, the spline 7256 is pushed into the compression ring 7254. While the outer diameter of the spline 7256 is wider than the minimum inner diameter of the compression ring 7254, since the spline 7256 is elastically deformable, the spline 7256 is caught by the compression ring 7254 and compressed. A vertical resistance force accompanying the deformation of the spline 7256 is applied to the compression ring 7254. Thus, a frictional force is generated between the damper 7200 and the sleeve 7015. Similar to other embodiments, this frictional force acts to weaken the force applied to the plunger rod and / or the drug container by the driving spring 7017.

[0217] The splines may have different shapes, which will be described below with reference to FIGS. 24a and 24b. As already described, FIG. 24a is a perspective view of the damper 7200 of FIG. 23. As can be seen in this figure, the splines 7256 of the damper 7200 have a constant length, with the starting and ending points aligned in the longitudinal direction and distributed circumferentially around the body of the damper 7200. With this arrangement, when the portion of the damper 7200 including the splines 7256 passes through the compression ring 7254, a substantially constant braking force can be obtained.

[0218] FIG. 24b shows another embodiment 7200' of the damper. The damper 7200' is provided with splines 7256a, 7256b, and 7256c having different lengths. As shown in FIG. 24b, due to the different lengths of the splines 7256a, 7256b, and 7256c, when the sleeve 7015 provided with the compression ring 7254 moves forward with respect to the damper 7200', the braking force applied by the braking mechanism can be changed.

[0219] The splines 7256 shown in FIG. 24a each extend approximately the same distance from the tip to the base of the damper 7200. Therefore, while the driving component 7015 moves with respect to the damper 7200, the frictional force between the compression ring 7254 and the damper 7200 is substantially constant throughout. On the other hand, in the embodiment shown in FIG. 24b, similar to changing the frictional force between the plunger rod 6015 and the damper by utilizing the different lengths of the grooves in the embodiment of FIG. 21, due to the different lengths of the splines 7256a, 7256b, and 7256c, the frictional force between the first driving component 7015 and the damper 7200' changes while the first driving component 7015 moves forward with respect to the damper 7200'.

[0220] FIG. 24b shows in particular the following. The first spline 7256a of the damper 7200' extends over the entire length of the tip of the damper 7200'. Since the second spline 7256b has a length that is approximately 3 / 4 of the length of the tip of the damper 7200', its end terminates approximately 1 / 4 of the length of the tip from the tip of the damper 7200'. Since the third spline 7256c has a length that is approximately 1 / 3 of the length of the tip of the damper 7200', its end terminates approximately 2 / 3 of the length of the tip from the tip of the damper 7200'.

[0221] In short, the splines 7256a, 7256b, 7256c are arranged such that the contact area between the splines 7256a, 7256b, 7256c and the compression ring 7015 changes while the damper 7200' passes through the compression ring 7015. In an embodiment, the plurality of splines includes at least one of the first spline 7256a and the second spline 7256b. The first spline 7256a and the second spline 7256b each extend only over a part of the damper 7200'. The first spline 7256a and the second spline 7256b have different lengths (i.e., dimensions measured along the long axis L of the damper 7200' and the syringe 1001). Separately from or in addition to that, at least one spline may vary its width along its longitudinal direction. Separately from or in addition to that, the above-mentioned "spline diameter" may vary according to the position along the longitudinal direction of the damper.

[0222] Since the lengths of the splines 7256a, 7256b, and 7256c are different, the density of the splines varies according to the distance along the major axis direction of the damper 7200’, so that the contact area per unit length changes. As a result, the braking force changes while the first driving component 7015 moves forward from the position where it has fully retracted to the extended position. At any position of the damper 7200’, the denser the splines, the wider the contact area between the damper 7200’ and the first driving component 7015, and thus the stronger the braking force. In other words, as the tip of the damper is approached, the proportion of the splines to the outer surface of the damper decreases, so that the braking force weakens. Conversely, if the splines are of the same length, a uniform braking force can be obtained along the longitudinal direction of the damper.

[0223] In any of the above dampers, the width of the spline (the dimension measured along the circumferential direction of the damper surrounding the major axis of the syringe) is constant. Additionally, one or more splines may vary in width along the longitudinal direction. The change in the width may be gradual, and the spline may taper along the longitudinal direction. Or the width may change stepwise along the longitudinal direction. Also by this, the contact area between the damper and the first driving component changes along the longitudinal direction of the damper.

[0224] The spline diameter may be uniform along the longitudinal direction of the damper. Additionally, the spline diameter may change along the longitudinal direction of the damper. The change in the spline diameter may be gradual, and the spline may taper along the longitudinal direction of the damper. Or the spline diameter may change stepwise along the longitudinal direction of the spline. Due to the change in the spline diameter, when the spline passes through the compression ring, the vertical resistance between the damper and the first driving component changes. Therefore, as the first driving component moves forward, the frictional force changes, so that the degree to which the force of the driving spring is weakened changes.

[0225] The above-described spline and groove are arranged parallel to the longitudinal direction of the damper, but the invention disclosed in this specification is not limited thereto. For example, the groove may be arranged spirally on the damper, or the spline may be arranged spirally on the first driving component. Even in this arrangement, similar to the above, the attributes of the spline or groove (i.e., width, length, radial position, or density) may vary as a function of the longitudinal position. By changing the contact area and / or the vertical resistance force between the damper and the first driving component with a spiral spline or groove, a desired change may be caused in the frictional force. However, it is easier to manufacture by providing the first driving component with a spline extending in its longitudinal axis direction.

[0226] Furthermore, the above-described embodiment includes a damper in which a spline is formed, and the damper is configured to interact with a sleeve that forms part of the drive device. However, it will be understood that a compression ring may be provided on a part of the plunger rod, such as the plunger rod 1015 in FIG. 15.

[0227] In yet another embodiment of the invention disclosed in this specification, the braking mechanism may be configured as follows to vary the frictional force between the first driving component and the damper. A compressive force is applied to the fixed damper by a tube, and the compressive force is varied by changing the wall thickness of the tube along its longitudinal direction. The structure of this embodiment is somewhat different from the above-described embodiment, but as will be explained below, the underlying principle (i.e., changing the compressive force applied by the damper and the driving component) is the same. In short, in these embodiments, the first driving component may be formed as an attached driving member including a compression sleeve. The compression sleeve has a constant inner diameter along its longitudinal direction, but its wall thickness varies. The compression sleeve may be integrally formed with the driving component configured to advance in the tip direction by the action of the driving spring, or may be another component coupled to the component. A damper is arranged inside the compression sleeve and fitted to the inner surface of the compression sleeve.

[0228] FIG. 25 is an isometric cross-sectional view of a braking mechanism including a first drive component 8015. The first drive component 8015 is formed of a main body 8015a, a compression ring 8015b, a damper 8200, and a pin 8202.

[0229] The damper 8200 includes a main body 8200a and a ferrule 8200b. The main body 8200a tapers such that its outer diameter decreases towards both ends and includes a threaded hole for accommodating the pin 8202. A portion with the maximum outer diameter is formed between both ends of the main body 8200a, and its outer diameter is wider than the outer diameter of the pin 8202. The ferrule 8200b is an annular member formed on the outside of the main body 8200a. The ferrule 8200b plastically deforms when it enters the compression sleeve 8015b, thereby weakening the force of the driving spring. The ferrule 8200b may be formed of metal, injection-molded resin, or other plastically deformable (i.e., substantially non-elastic-deformable) material. The ferrule 8200b may be harder and stronger than the compression sleeve 8015b.

[0230] The ferrule 8200b surrounds the main body 8200a and has an outer diameter wider than that of the main body 8200a, thus forming a surface that contacts the inner wall of the drive component in the same manner as the braking members of other embodiments disclosed in this specification. In the illustrated embodiment, the ferrule 8200b is attached on the main body 8200a, but it will be understood that if the outer diameter of the ferrule is wider than the outer diameter of the pin 8202, the main body may be omitted and the ferrule may be directly attached to the pin 8202.

[0231] Referring further to FIG. 25, the first driving component 8015 includes a main body 8015a and a compression sleeve 8015b. The main body 8015a is a substantially cylindrical member and is provided with an annular ring 8260. The annular ring 8260 is formed with a shoulder facing in the tip direction, and the shoulder is pressed by the shoulder 8262 of the compression sleeve 8015b. By these shoulders being adjacent to each other, the main body 8015a is prevented from moving toward the tip side with respect to the compression sleeve 8015b. Therefore, it is ensured that the main body 8015a and the compression sleeve 8015b move together (at least in the tip direction) under the action of the driving spring.

[0232] The compression sleeve 8015b is an elongated tubular shape extending from the shoulder in the base end direction, and a ferrule 8200b can be disposed therein. Hereinafter, the compression sleeve 8015b will be described in more detail with reference to FIGS. 26a-26c.

[0233] FIG. 26a is an end view of the compression sleeve 8015b. As shown in FIG. 26a, the cross-section of the compression sleeve 8015b is substantially an annular ring.

[0234] FIG. 26b is a side view of the compression sleeve 8015b. As shown in this figure, the compression sleeve 8015b includes a storage portion 8264 (a shoulder 8262 facing in the base end direction is formed at its base end) and a compression portion 8266 (extending from the storage portion 8264 toward the open base end). As seen in FIG. 26b, the outer diameter of the compression portion 8266 gradually decreases from the maximum value at the tip to the minimum value at the base end.

[0235] FIG. 26c is a cross-sectional view taken along the plane F-F' shown in FIG. 26a. As shown in FIG. 26c, the inner diameter d of the compression portion 8266 c is constant. The outer diameter of the compression portion 8266 is the first outer diameter d at the tip (the end closer to the storage portion 8264) d to the second outer diameter d at the base end (the end farther from the storage portion 8264) pSince it gradually decreases until [a certain point], the thickness of the wall 8268 of the compression part 8266 gradually decreases along its longitudinal direction, from the maximum value at the tip to the minimum value at the base end.

[0236] Due to the change in the wall thickness of the compression sleeve 8015b, the hoop stress (circumferential stress) between the damper and the first driving component changes as a function of the position of the first driving component relative to the damper. The change in the hoop stress changes the vertical resistance between the first driving component and the damper. As a result, since the degree of interference fit between the compression sleeve 8015b and the damper changes, the degree to which the force of the driving spring applied to the plunger and / or the medicine container is weakened changes.

[0237] In the embodiment, it is described that the damper is arranged inside the first driving component, but the invention disclosed in this specification is not limited to that arrangement. For example, the braking of the driving spring may be realized using a damper as follows. This damper is annular and surrounds the first driving component, generating frictional force at various stages of the forward movement of the first driving component to weaken the force of the driving spring.

[0238] FIG. 27 is a cross-sectional view of Example 2001 of a syringe (described with reference to FIG. 12). In this syringe 2001, an annular damper 2200 is arranged around the first driving component and fits on the outer peripheral surface of the first driving component. FIG. 27 shows the base end portion of the syringe 2001 described with reference to FIG. 12.

[0239] The annular damper 2200 shown in Fig. 27 is formed as an O-ring, installed in the vertical hole of the proximal housing 2032, and coupled to the proximal housing 2032 so as not to move in the direction of the major axis of the proximal housing 2032. The annular damper 2200 surrounds the outer wall of the first driving component formed as the latch 2040 and fits onto its outer wall. When the annular damper 2200 is not receiving force, its inner diameter is slightly narrower than the outer diameter of the outer wall of the first driving component (latch 2040). The first driving component (latch 2040) is coupled to the driving spring 2017 by a driving sleeve formed as the overhanging portion 2042. Therefore, when the annular damper 2200 surrounds the first driving component (latch 2040), a perpendicular resistance force is applied to the outer peripheral surface of the first driving component (latch 2040). As a result, a frictional force is generated between the annular damper 2200 and the first driving component (latch 2040), resisting the force of the driving spring 2017.

[0240] In Fig. 27, the latch 2040 is arranged so as to always remain in contact with the annular damper 2200 during the operation of the syringe. That is, since the outer diameter of the latch 2040 is substantially uniform, the braking force does not depend on the position of the first driving component. However, the embodiments of the invention are not limited to this. For example, due to the changing outer diameter of the latch 2040, the annular damper 2200 may apply perpendicular resistance forces of different strengths to the first driving component 2015 at various stages during the period when the driving spring 2017 extends. Separately or in addition to that, due to the changing outer diameter of the latch 2040, during the period when the driving spring 2017 extends, there may be stages where the annular damper 2200 and the latch 2040 are in contact and stages where they are not in contact. By changing the outer diameter of the sleeve in this way, the frictional force can be changed in various patterns. Those patterns include, but are not limited to, any of those described in this specification.

[0241] In the embodiments of the invention, it is described that a fixed damper applies a frictional force to a component moved by a driving spring, but the inventor recognizes that other means of weakening the force of the driving spring are also possible. For example, FIGS. 28a-28d show various different configurations of an elastomer that directly contacts a driving spring in a compressed state. Each elastomer is arranged to resist the extension of the driving spring, i.e., so that only one turn of the spring can advance at a time.

[0242] FIG. 28a shows an elastomer formed as an elastomer sheath 18a surrounding a driving spring 17a in a fully compressed state. The elastomer sheath 18a has an inner diameter that is narrower than the outer diameter of the driving spring 17a when not under force. The elastomer sheath 18a is also longer than the driving spring 17a in a fully compressed state. Therefore, when the elastomer sheath 18a is expanded to surround the driving spring 17a and the ends of the elastomer sheath 18a extended to the outside of both ends of the driving spring 17a apply a compressive force to the driving spring 17a by their contraction, the elastomer sheath 18a effectively wraps around the driving spring 17a. Therefore, an axial force (i.e., a force in a direction parallel to the axis of the driving spring 17a) is applied to one turn at each end of the driving spring 17a. This force applied by the elastomer sheath 18a prevents all turns of the driving spring 17a from extending at once. Only one turn is released from the end of the elastomer sheath 18a at a time. When one turn is released, the axial force of the elastomer sheath 18a is applied to the next turn, resisting the extension of that turn. Thereafter, it is a repetition of that.

[0243] FIG. 28b shows an elastomer inner tube 18b that functions substantially the same as the elastomer sheath 18a of FIG. 28a. The elastomer inner tube 18b is also positioned coaxially with the driving spring 17b. However, the elastomer inner tube 18b is formed inside the driving spring 17b. The elastomer inner tube 18b has an outer diameter that is wider than the inner diameter of the driving spring 17b and is longer than the driving spring 17b in a compressed state, so both ends apply an axial force to both ends of the driving spring 17b. Thereby, the same effect as the effect described with reference to FIG. 28a is obtained.

[0244] Figure 28c shows a rigid support tube 18c that is coaxially arranged with and surrounds the driving spring 17c. The support tube 18c supports an elastomeric ridge 188c on the inner surface at one end thereof. The elastomeric ridge 188c extends circumferentially along the inner peripheral surface of the support tube 18c. Since the inner diameter of the elastomeric ridge 188c is narrower than the outer diameter of the driving spring 17c, the elastomeric ridge 188c applies an axial force to the end of the driving spring 17c and resists the elongation of the first coil. When the first coil is released from the end of the support tube 18c, the elastomeric ridge 188c applies an axial force to the next coil. Thereafter, it is repeated.

[0245] Figure 28d shows a configuration similar to that of Figure 28c. However, the support tube 18d included in the configuration is arranged inside the driving spring 17d, and the elastomeric ridge 188d extends circumferentially along the outer peripheral surface at one end of the support tube 18d. Since the outer diameter of the elastomeric ridge 188d is wider than the inner diameter of the driving spring 17d, the driving spring 17d receives an axial force from the elastomeric ridge 188d when each coil of the driving spring 17d is sequentially released from the end of the support tube 18d. Therefore, also with this configuration, the above-described effect that the coils of the driving spring 17d are released one by one can be obtained.

[0246] Figure 29 shows a method of manufacturing a syringe according to the invention disclosed in this specification. In step 201, a housing having a major axis is prepared. In step 203, a damper is attached to the housing so as not to translate along the major axis with respect to the housing. In step 205, a driving spring is installed in the housing. In step 207, a first driving component is installed in the housing. Thereby, the damper is coaxially arranged inside the first driving component, and the damper and the first driving component are configured to be press-fitted so that the first driving component moves along the major axis with respect to the damper by the driving spring. As an additional step, in step 209, a deformable braking member may be overmolded on an elongated member (for example, a mandrel) forming the damper.

[0247] As will be understood by the reader, the above steps can be performed in any order. This method may further include the step of providing any of the features previously described for the embodiments shown in FIGS. 15 - 28d.

[0248] According to the description of the device disclosed in this specification, a certain method for braking a driving spring within a syringe is provided. This method includes the following steps. - Advancing the medicine container from the retracted position to the extended position relative to the syringe housing using the driving spring. The driving spring transmits power to the medicine container through the first driving component. - Moving the first driving component relative to the damper. The damper is arranged coaxially with respect to the first driving component. - During the movement of the first driving component relative to the damper, causing an interference fit between the surface of the first driving component and the damper.

[0249] As will be understood from the description of the above embodiments, by adjusting the normal force and / or the coefficient of kinetic friction between the damper and the first driving component, the frictional force between these components is adjusted. The normal force depends on the way the damper and the first driving component are fitted, and / or the elasticity or rigidity of either component, and / or the amount of displacement of a part of either component (which is usually proportional to its restoring force in the case of an elastomer). The coefficient of kinetic friction depends on the contact area between the damper and the first driving component, and / or the coefficient of kinetic friction per unit contact area.

[0250] As will be understood by those skilled in the art from the described embodiments, the cross-section of the damper or the braking member is uniform. However, the invention disclosed in this specification is not limited thereto. For example, by having various cross-sections of the damper, the normal force between the damper and the first driving component may vary according to the position of the damper relative to the compression region of the first driving component. By this means, the degree of weakening of the force of the driving spring can also be varied according to the relative position between the damper and the first driving component.

[0251] In the above detailed description, a system and method for weakening power in a syringe having a specific mechanism for inserting and removing a needle were described. However, it will be understood by those skilled in the art that the invention is not limited to the use of the syringe examples described in this specification. Rather, for other dosing devices, one or more advantages of the invention can be obtained. This will be apparent to those skilled in the art in view of the above detailed description.

[0252] Although the drive spring has been described, the inventor recognizes that embodiments of the invention can also be described for more general elastic members (the drive spring is only one example thereof).

[0253] Although the case of one damper has been described, the syringe may be provided with a braking mechanism including two or more dampers. Those dampers can weaken the force of the drive spring by acting on each other. Further, although the syringe has been described, embodiments of the invention can be said to relate to both the braking mechanism of the syringe and the braking mechanism for the drive device of the syringe.

[0254] The braking mechanism according to the invention disclosed in this specification may be implemented in a syringe configured to automatically administer a single dose of medicine. In particular, it may be used in an automatic syringe of a type that advances a medicine container to administer a single dose of medicine and automatically retracts the used medicine container relative to the housing.

[0255] The braking mechanism described in this specification may be combined with a power pack according to the above features of the invention and / or with one or more of a connection device and a passive safety shield to be described in more detail below.

[0256] [Connection device] The invention disclosed in this specification also provides an example of a connection device configured to connect a hypodermic needle inside a sealed medicine container.

[0257] Figure 30a is a cross-sectional view of a connection device 1500 for a syringe. The syringe is for drug administration according to the invention disclosed in this specification, such as that shown in FIG. 1. The connection device 1500 shown in FIG. 30a is in a storage state. The connection device 1500 includes a drug container 1007. The drug container 1007 is filled with a drug M and is provided with a cap 1502. The drug container 1007 is sealed by a partition wall 1008. The cap 1502 has a first rib 1504 and a second rib 1506. These ribs 1504, 1506 surround the circumference of the cap 1502 and form a first recess 1508 for positioning therebetween. A seal element 1510 is in contact with the outer surface 1524 of the cap 1502 and is sandwiched between the first rib 1504 and the second rib 1506 in the first recess 1508. The seal element 1510 surrounds the circumference of the cap 1502, is chemically bonded to the cap 1502, and is particularly overmolded. Thereby, the cap 1502 and the seal element 1510 are integrated. The seal element 1510 is made of a flexible material and is crushed between the two ribs 1504, 1506 (while being chemically bonded to the cap 1502).

[0258] The tip of the cap 1502 (including the first rib 1504 and the second rib 1506) and the seal element 1510 are installed in the needle hub 1011. The needle hub 1011 includes a main body 1512 and an elongated portion 1514 extending from the main body 1512. Inside the main body 1512 of the needle hub 1011, the surfaces of the needle hub 1011, the cap 1502, and the seal element 1510 partition a cavity 1516, in which the free end 1518 of the needle 1009 is located. Looking at the inner surface of the needle hub 1011, the needle hub 1011 has a first inner surface 1520. The first inner surface 1520 is circular, extends perpendicular to the needle 1009, and faces the cap 1502. The needle hub 1011 also includes a proximal-side protrusion 1522 extending in the inner circumferential direction toward the needle 1009. The proximal-side protrusion 1522 is annular, extends around the outer peripheral surface of the cap 1502, and is contactable therewith. The proximal-side protrusion 1522 also contacts, optionally, the second rib 1506, particularly the surface on its proximal side. Thus, the needle hub 1011 covers the tip of the cap 1502 (including the first rib 1504, the second rib 1506, and the seal element 1510).

[0259] The needle hub 1011 also has a second inner surface 1528. The second inner surface 1528 is tubular, extends parallel to the needle 1009, and is connected to the first inner surface 1520 and the proximal-side protrusion 1522. Since the needle hub 1011 is made of a rigid material, the soft seal element 1510 is crushed between the first rib 1504 and the second rib 1506 of the cap 1502 and also against the second inner surface 1528 of the needle hub 1011. Accordingly, the space between the outer surface 1524 of the cap 1502 and the second inner surface 1528 of the needle hub 1011 is sealed. This seal is formed by the seal element 1510.

[0260] The needle 1009 penetrates through the first inner surface 1520 and the elongated portion 1514 of the needle hub 1011. The needle 1009 further reaches the tip of the connection device 1500 and contacts a needle shield (corresponding to the needle seal 1004 shown in FIG. 1).

[0261] The needle hub 1011 has an annular protrusion 1526 at the tip of its body 1512. The purpose of this protrusion will be described below with reference to FIG. 30b.

[0262] FIG. 30a shows the first state (the state before injection) of the connection device 1500. In the first state, the free end 1518 of the needle 1009 is held at a position away from the partition wall 1008. FIG. 30b shows the second state of the connection device 1500. In the second state, the needle 1009 penetrates the partition wall 1008. The process by which the connection device 1500 transitions from the first state shown in FIG. 30a to the second state shown in FIG. 30b will be described below.

[0263] The process of performing an injection is described with reference to FIG. 1, so it will be understood by the reader that the same description also applies to this embodiment. As described, during the injection, since the needle hub 1011 and the drug container 1007 advance in the tip direction, the subcutaneous injection needle 1009 pierces the injection site. Since the plunger rod 1015 continues to advance (see FIG. 1), the drug container 1007 further advances and moves relative to the needle hub 1011 to continue sealing between the needle hub 1011, particularly its second inner surface 1528 and the outer surface 1524 of the cap 1502. Thereafter, the needle 1009 penetrates the partition wall 1008, enabling the drug M to be discharged from the drug container 1007 through the subcutaneous injection needle 1009. As the plunger 1013 moves in the drug container 1007 toward the partition wall 1008, the drug M is discharged from the drug container 1007 through the subcutaneous injection needle 1009. Thus, the injection is performed.

[0264] Since the needle hub 1011 advances in the tip direction during the injection, the annular protrusion 1526 of the needle hub 1011 catches on the soft latch arms 1402 (see FIGS. 47a - 47c and the description thereof below) and pushes them radially outward. As a result, the soft latch arms 1402 disengage from the latch surface 1404. Consequently, the safety shield 1019 is no longer locked in the retracted position.

[0265] The following describes other connection devices used in a syringe for drug administration with reference to FIGS. 31a and 31b. The connection device shown in FIG. 31a is similar to those shown in FIGS. 30a and 30b, but different in the following points. First, the seal element 9510 is an O-ring. Similar to the previous one, the seal element 9510 is made of a flexible material. The seal element 9510 is installed in the positioning recess 9508 of the cap 9502 (made of a hard material). The needle hub 9011 (also made of a hard material) also has a similar recess 9530. When the connection device 9500 is held in the first state, that is, the state where the free end of the needle 9009 is separated from the partition wall 9008, the recess 9530 of the needle hub 9011 is aligned with the seal element 9510, which helps to push the seal element 9510 into the positioning recess 9508 of the cap 9502. In this way, a seal is formed between the cap 9502 and the needle hub 9011 by the seal element 9510, and a cavity 9516 is formed.

[0266] As described above, during injection, the drug container 9007 advances (towards the tip side) relative to the needle hub 9011, so the seal between the needle hub 9011 and the cap 9502 is maintained.

[0267] FIG. 31b shows the second state of the connection device 9500 in FIG. 31a. That is, it shows the state when the needle 9009 penetrates the partition wall 9008. The seal element 9510 is crushed against the inner surface of the needle hub 9011 in the first recess 9508 of the cap 9508. The positioning protrusion 9532 of the needle hub 9011 is aligned with and locked in the second positioning recess 9534 of the cap 9502. The second recess 9534 is located adjacent to the first recess 9530. When the connection device 9500 is in the second state, the protrusion 9532 is locked in the second recess 9534, preventing the needle hub 9011 from moving towards the proximal end side relative to the cap 9502 (therefore, the needle 9009 cannot be removed from the drug container 9007).

[0268] FIG. 32a shows a third connection device 10500. The third connection device 10500 includes elements common to the above two connection devices (shown in FIGS. 30a, 30b, 31a, and 31b), but is different in the following points. First, (in the connection devices shown in FIGS. 30a, 30b, 31a, and 31b, the cap was installed inside the needle hub, whereas) the third connection device 10500 is configured such that the needle hub 10011 is installed inside the cap 10502. When the third connection device 10500 is in the first state (the state before injection), a part of the needle hub 10011 is installed inside the cap 10502.

[0269] The partition wall 10008 also has a different shape from the partition walls shown in FIGS. 30a, 30b, 31a, and 31b, and additional functions are added. The partition wall 10008 includes a main part 10008a and an elongated part 10008b. The elongated part 10008b is an annular ridge and forms a cavity 10516. The needle hub 10011 also includes an elongated part 10550.

[0270] The seal element 10510 is formed by a part of the partition wall 10008, particularly the tip of the elongated part 10008b, and is sandwiched between the inner surface of the cap 10502 and the outer surface of the needle hub 10011. Both the cap 10502 and the needle hub 10011 are made of a hard material (which may or may not be the same material). The partition wall 10008 is made of a soft material. Therefore, the annular ridge 10008b of the partition wall 10008 is crushed between the cap 10502 and the needle hub 10011 to form a seal. Thereby, a flow path, that is, the cavity 10516 is formed.

[0271] The cap 10502 includes a first shoulder 10538 and a second shoulder 10540. At each of the shoulders 10538, 10540, the radius of the cap 10502 increases sharply (as going from the tip to the base of the cap 10502). The seal element (i.e., the tip of the partition wall 10008) is crushed between the first shoulder 10538 and the needle hub 10011. In this way, since the seal element is pressed against the clearly shaped part of the cap 10502, a secure seal can be obtained. The part of the cap 10502 located on the base side with respect to the first shoulder 10538 has a larger radius than the tip of the cap 10502, so the movement of the medicine container 10007 and the partition wall 10008 with respect to the needle hub 10011 is not overly restricted. The second shoulder 10540 of the cap 10502 forms a seal by crushing the partition wall 10008.

[0272] The cap 10502 surrounds the tip of the medicine container 10007. The tip of the medicine container 10007 includes a first cylindrical portion 10542 with a first radius and a second cylindrical portion 10544 with a second radius smaller than the first radius. The second cylindrical portion 10544 is farther from the partition wall 10008 than the first cylindrical portion 10542. The cap 10502 is in contact with the first cylindrical portion 10542 of the medicine container 10007 and has a rib 10055 (with a smaller radius compared to the first cylindrical portion 10542) that is locked by the second cylindrical portion 10544. Thereby, the cap 10502 is easily fixed to the medicine container 10007.

[0273] At the tip of the cap 10502, there is a hole for accommodating a part of the needle hub 10011. The cap 10502 includes a protrusion 10546 that protrudes in the inner circumferential direction into this hole. The needle hub 10011 has a protrusion 10566 that catches on the protrusion 10546 of the cap 10502, preventing the needle hub 10011 from moving toward the tip side with respect to the cap 10502 and coming off the cap 10502. The protrusion 10546 of the cap 10502 has a slope, and the tip is thinner than the base end. The needle hub 10011 has a slope 10562, and when the third connecting device 10500 transitions from the first state to the second state as described later, it catches on the slope of the protrusion 10546 of the cap 10502. The needle hub 10011 also has a recess 10554. When the third connecting device 10500 is in the second state, the protrusion 10546 of the cap 10502 is locked in the recess 10554, so after the third connecting device 10500 reaches the second state, the needle hub 10011 cannot move toward the tip side with respect to the cap 10502.

[0274] The needle hub 10011 also has a disk 10556 that spreads in the outer circumferential direction. The disk 10556 has three holes arranged at equal intervals in the circumferential direction of the needle hub 10011. These holes can be seen in Fig. 32c. There are three wing portions 10558 in the holes, and they divide the holes. When the third connecting device 10500 is in the first state, the tip of the cap 10502 is accommodated in the holes, and when the third connecting device 10500 transitions from the first state to the second state, it prevents the twisting of the needle hub 10011 with respect to the cap 10502. This will be explained in more detail later.

[0275] The cap 10502 has three recesses 10560. The recesses 10560 are configured such that when the needle hub 10011 moves toward the base end side with respect to the cap 10502, the three wing portions 10558 of the needle hub 10011 are accommodated.

[0276] While the third connecting device 10500 transitions from the first state to the second state, the medicine container 10007 moves toward the distal end side with respect to the needle hub 10011. At this time, the elongated portion 10550 of the needle hub 10011 is received inside the vertical hole of the partition wall 10008, that is, inside the cavity 10516. A seal element 10510 is pressed against the continuous surface of the elongated portion 10550 of the needle hub 10011 by the cap 10502. Thus, while the third connecting device 10500 transitions from the first state (shown in FIG. 32a) to the second state (shown in FIG. 32b), the seal element 10510 continues to be crushed between the inner surface of the cap 10502 and the outer surface of the needle hub 10011. The fact that the surface of the needle hub 10011 is thus smooth means that the needle hub 10011 is easy to manufacture. The absence of a positioning tool also means that the seal element 10510 is less likely to be damaged when moving over the needle hub 10011.

[0277] When the needle hub 10011 moves further, the slope 10564 of the protrusion 10546 of the cap 10502 rides on the slope 10562 of the needle hub 10011, so the tip of the cap 10502 is expanded by the width of the needle hub 10011. As the needle hub 10011 continues to move toward the proximal end side with respect to the cap 10502, eventually the needle 10009 penetrates the partition wall 10008. A flow path is opened between the medicine container 10007 and the needle 10009, and the medicine M is discharged. When the protrusion 10546 of the cap 10502 reaches a position where it fits into the recess 10554 of the needle hub 10011 (shown in FIG. 32b), the needle hub 10011 cannot move toward the distal end side from that position with respect to the cap 10502.

[0278] FIG. 32c is another view of the third connecting device 10500 when the syringe is in the first state (the state before injection). As shown, the tip of the cap 10502 is received inside the hole of the disk 10556 of the needle hub 10011. The cap 10502 has a recess 10560, and when the needle hub 10011 moves toward the proximal end side with respect to the cap 10502, the wing portion 10558 of the disk 10556 is received in the recess 10560.

[0279] FIG. 33 shows the fourth connection device 11500. The fourth connection device 11500 includes a sealing sleeve 11568 surrounding the cap 11502. The base end of the sealing sleeve 11568 is in contact with the outer surface of the medicine container 11007 and is held in place by a fixing ring 11572 surrounding the medicine container 11007. The fourth connection device 11500 also includes a rigid needle hub 11011. The needle hub 11011 is penetrated by a needle 11009. The needle hub 11011 is in contact with the inner surface at the tip of the sealing sleeve 11568. Seals are formed both between the cap 11502 and the sealing sleeve 11568 and between the needle hub 11011 and the sealing sleeve 11568. The cavity 11570 is partitioned by the needle hub 11011, the sealing sleeve 11568, the cap 11502, and the partition wall 11008. When the fourth connection device 11500 is in the first state (storage state), the free end 11518 of the needle 11009 is located in the cavity 11570.

[0280] When a force in the tip direction is applied to the medicine container 11007, the medicine container 11007 moves toward the tip side with respect to the needle 11009 and the needle hub 11011. As the medicine container 11007 advances, the sealing sleeve 11568 is crushed and bent in the outer peripheral direction, so that the needle 11009 penetrates the partition wall 11008. As a result, the medicine M is discharged through the needle 11009.

[0281] FIG. 34 shows the fifth connection device 12500. Similar to the fourth connection device 11500 shown in FIG. 33, the fifth connection device 12500 also uses a sealing sleeve 12568. The sealing sleeve 12568 surrounds the cap 12502 and spreads in the inner circumferential direction at the base end of the cap 12502. Thereby, the sealing sleeve 12568 is fixed to the cap 12502. A seal is formed between the inner surface of the sealing sleeve 12568 and the outer surface 12574 of the cap 12502.

[0282] The tip of the seal sleeve 12568 is locked to the rigid needle hub 12011. The needle hub 12011 is penetrated by the needle 12009. A seal is formed between the needle hub 12011 and the tip of the seal sleeve 12568.

[0283] The seal sleeve 12568 has a lip 12576 at its tip. The lip 12576 extends around the tip of the seal sleeve 12568. When the syringe is in the first state, the lip 12576 extends in the proximal direction.

[0284] When a force in the distal direction is applied to the drug container 12007, the drug container 12007 moves relative to the needle hub 12011 and the needle 12009. When the drug container 12007 advances, the seal sleeve 12568 (particularly the portion not in contact with the outer surface of the cap 12502) collapses outwardly, the lip 12576 turns inside out and extends in the distal direction, surrounding the tip of the needle hub 12011. Thereby, since the needle hub 12011 is guided, the drug container 12007 is surely moved toward the center. Eventually, the needle 12009 penetrates the partition wall 12508, and the drug M is discharged through the needle 12009.

[0285] Figure 35 shows the sixth connecting device 13500. The sixth connecting device 13500 also uses a seal sleeve 13568. In this configuration, the seal sleeve 13568 surrounds the cap 13502 and expands in the inner circumferential direction at the proximal end of the cap 13502. Thereby, the seal sleeve 13568 is fixed to the cap 13502. There is a ridge at the tip of the seal sleeve 13568, which is locked to the ridge at the proximal end of the needle hub 13011. Thereby, a seal is formed between the seal sleeve 13568 and the needle hub 13011. The needle hub 13011 is made of a rigid material, and the seal sleeve 13568 is made of a flexible material.

[0286] A seal is also formed between the seal sleeve 13568 and the outer surface 13574 of the cap 13502. The cavity 13578 is partitioned by the inner wall of the needle hub 13011 and the cap 13502, and the partition wall 13008. When the sixth connecting device 13500 is in the first state, the free end 13518 of the needle 13009 is located in the cavity 13578.

[0287] When a tip - direction force is applied to the medicine container 13007, the medicine container 13007 moves toward the tip side with respect to the needle 13009 and the needle hub 13011. As the medicine container 13007 advances, the wall 13580 of the needle hub 13011 moves inside the seal sleeve 13568 (particularly, the inner - peripheral side). During this movement, the seal between the seal sleeve 13568 and the outer surface of the needle hub 13011 is maintained. Eventually, since the needle 13009 penetrates the partition wall 13008, the medicine M is discharged through the needle 13009.

[0288] Figure 36 shows the seventh connecting device 14500. The connecting device 14500 in Figure 36 includes a seal element in the form of a stopper 14582 that contacts the cap 14502 of the medicine container 14007. Additionally, the stopper 14582 may contact a first outer cap (not shown) that surrounds the cap 14502. The advantage of using such an outer cap is that for the purpose of using the medicine container 14007 and its cap 14502 together with the seventh connecting device 14500, there is no need to make any modifications to them, to shape them in a specific form, or to provide specific instruments for them. The stopper 14582 is made of a soft material.

[0289] The needle hub 14011 is in contact with the stopper 14582. When the seventh connection device 14500 is in the first state, a part of the needle hub 14011 is located inside the stopper 14582 (i.e., on the inner circumferential side). The needle hub 14011 is made of a rigid material and includes wings 14586 for maintaining stability. A part of the cap 14502, the stopper 14582, and the needle hub 14011 is surrounded by a second outer cap 14588. The second outer cap 14588 has a plurality of vertical holes, and when the seventh connection device 14500 transitions from the first state to the second state, the wings 14586 move through those vertical holes. By locking the wings 14586 in the vertical holes of the second outer cap 14588 in this way, rotation of the needle hub 14011 relative to the stopper 14582 is prevented when the seventh connection device 14500 transitions to the second state. The vertical holes of the second outer cap 14588 are not shown in FIG. 36 but are similar to the vertical holes of the cap 10502 shown in FIG. 32c. The wings 14586 further prevent the needle hub 14011 from going too far in the proximal direction, as will be described later.

[0290] There is a recess 14590 adjacent to the wings 14586 of the needle hub 14011. When the syringe is in the second state, a ridge 14592 located at the tip of the stopper 14582 is locked in the recess 14590.

[0291] (As shown in FIG. 36) In the first state, a seal is formed between the outer surface of the needle hub 14011 and the inner surface of the stopper 14582. The stopper 14582, the needle hub 14011, the tip of the cap 14502, and the partition wall 14008 divide the cavity 14578. When the seventh connection device 14500 is in the first state, the free end 14518 of the needle 14009 is located in the cavity 14578.

[0292] When a force in the distal direction is applied to the medicine container 14007, the medicine container 14007 moves distally with respect to the needle 14009 and the needle hub 14011 (together with the second outer cap 14588 and the stopper 14582). As the medicine container 14007 advances, the proximal end of the needle hub 14011 moves inside the wall 14594 of the stopper 14582 (particularly, the inner circumferential side). During this movement, a seal is maintained between the stopper 14582 and the outer surface of the needle hub 14011. The needle hub 14011 moves with respect to the stopper 14582, and eventually the needle 14009 penetrates the partition wall 14008 and the medicine M is discharged through the needle 14009. As described above, since the wing portion 14586 of the needle hub 14011 fits into the vertical hole of the second outer cap 14588, it eventually abuts against the tip of the stopper 14582. Therefore, further movement of the needle hub 14011 toward the proximal end with respect to the stopper 14582 is prevented. Moreover, since the recess 14590 of the needle hub 14011 is locked to the ridge 14592 of the stopper 14582, the needle hub 14011 is also prevented from returning toward the distal end with respect to the stopper 14582.

[0293] FIG. 37 shows the eighth connection device 15500. The eighth connection device 15500 includes a container 15596. The container 15596 surrounds and houses the proximal end of the needle 15009, the proximal end of the needle hub 15011, the first seal element 15598a, and the second seal element 15598b. The seal elements 15598a and 15598b are formed as two flexible rings. The rings 15598a and 15598b are made of a soft material. On the other hand, the container 15596 is made of a hard material. The first ring 15598a is sandwiched between the inner surface of the container 15596 and the outer surface 15574 of the cap 15502. A seal is formed between the inner surface of the container 15596 and the outer surface 15574 of the cap 15502 by the first ring 15598a. The second ring 15598b is sandwiched between the inner surface of the container 15596 and the outer surface of the needle hub 15011. A seal is formed between the inner surface of the container 15596 and the outer surface of the needle hub 15011 by the second ring 15598b. A cavity 15578 is partitioned by the container 15596, the proximal end of the needle hub 15011, and the inner surface of the tip of the cap 15502, and is sealed by the rings 15598a and 15598b. When the eighth connection device 15500 is in the first state (shown in FIG. 37), the free end 15518 of the needle 15009 is located in the cavity 15578.

[0294] When a force in the distal direction is applied to the medicine container 15007, the medicine container 15007 moves distally with respect to the needle 15009 and the needle hub 15011. As the medicine container 15007 advances, the tip of the container 15596 bends and opens, and moves to the outer peripheral side of the tip of the eighth connection device 15500. While the medicine container 15007 is advancing, the seal between the needle hub 15011 and the container 15596 is maintained (by the second ring 15598b), and the seal between the cap 15502 and the container 15596 is maintained (by the first ring 15598a). Eventually, the needle 15009 penetrates the partition wall 15008 and the medicine M is discharged through the needle 15009.

[0295] Figure 38 shows the ninth connecting device 16500. Similar to what is shown in Figure 35, the ninth connecting device 16500 uses, for example, a seal sleeve 16568. The seal sleeve 16568 is made of a soft material. In this embodiment, the seal sleeve 16568 surrounds the cap 16502 and spreads radially inward at its proximal end. As a result, the seal sleeve 16568 is fixed to the cap 16502. The distal end of the seal sleeve 16568 is sandwiched between the inner surface 16600 of the needle hub 16011 and the outer surface 16574 of the cap 16502. A seal between the cap 16502 and the inner surface 16600 of the needle hub 16011 is formed by the seal sleeve 16568. A cavity 16578 is partitioned by the inner surfaces of the needle hub 16011, the cap 16502, and the partition wall 16008 and is sealed by the seal sleeve 16568. When the eighth connecting device 16500 is in the first state, the free end 16518 of the needle 16009 is located in the cavity 16578.

[0296] The outer surface of the seal sleeve 16568 is provided with a positioning tool. When the ninth connecting device 16500 is in the first state, the positioning tool continues to hold the proximal end of the needle hub 16011. In this case, the positioning tools are ridges 16602a and 16602b. When the ninth connecting device 16500 is in the first state, a ridge 16604 located at the proximal end of the needle hub 16011 is installed between the ridges 16602a and 16602b, so that the needle hub 16011 is held relative to the medicine container 16007.

[0297] When a force in the distal direction is applied to the medicine container 16007, the medicine container 16007 moves distally relative to the needle 16009 and the needle hub 16011, so that the ridge 16604 of the needle hub 16011 overrides the ridge 16602a of the seal sleeve 16568. While the medicine container 16007 is advancing, the seal between the cap 16502 and the inner surface 16600 of the needle hub 16011 is maintained. Eventually, the needle 16009 penetrates the partition wall 16008 and the medicine M is discharged through the needle 16009.

[0298] FIG. 39 shows the tenth connecting device 17500. The tenth connecting device 17500 is mostly the same as that shown in FIG. 34, except for the following differences. The connecting device 17500 in FIG. 39 does not have the lip 12576 shown in FIG. 34. (However, it will be understood that it is possible to incorporate a lip in this embodiment.) Similar to the connecting device in FIG. 34, the connecting device 17500 in FIG. 39 includes a sealing sleeve 17568. In the case of the connecting device 17500 in FIG. 39, the region of the sealing sleeve 17568 that does not contact the outer surface of the cap 17502 (i.e., the region sandwiched between the needle hub 17011 and the cap 17502) has a reduced thickness compared to the portions that contact the cap 17502 and the needle hub 17011 respectively. Thereby, at this position (i.e., the position where the thickness is reduced), the sealing sleeve 17568 is likely to be crushed, which is useful for better control of the components of the tenth connecting device 17500.

[0299] FIG. 40 shows the eleventh connecting device 18500. In the eleventh connecting device 18500, the needle hub 18011 has a female thread 18606 of a square thread. The female thread 18606 is configured to mesh with a male thread formed on a sleeve 18608 that surrounds the cap 18502 of the medicine container 18007. The sleeve 18608 is made of a soft material. When the eleventh connecting device 18500 is in the first state, that is, before the needle 18009 penetrates the partition wall (not shown) of the cap 18502, the male thread of the sleeve 18608 forms a seal with the female thread 18606 of the needle hub 18011.

[0300] When a tip - direction force is applied to the medicine container (not shown), the male thread of the sleeve 18608 and the female thread 18606 of the needle hub 18011 overcome each other, so that the medicine container moves toward the tip side with respect to the needle 18009 and the needle hub 18011. As the medicine container advances, the needle 18009 penetrates the partition wall and the medicine is discharged through the needle 18009.

[0301] FIG. 41 shows the twelfth connecting device 19500. The twelfth connecting device 19500 is the same as that shown in FIG. 30a, but in this case, the seal element 19510 is adhered to the inner surface of the needle hub 19011 instead of the outer surface of the cap 19502. Further, there is only one rib 19610 on the outer surface of the cap 19502 (corresponding to the rib 1504 in FIG. 30a). The seal element 19510 is crushed between the rib 19610 and the proximal end 19612 of the needle hub 19011. In other respects, the operation of the twelfth connecting device 19500 is the same as the operation described with reference to FIGS. 30a and 30b.

[0302] The following will be understood. The rib 19610 may not be present, and instead, the seal element may be prevented from moving toward the proximal end with respect to the needle hub by the friction between the seal element and the cap.

[0303] FIG. 42 shows the thirteenth connecting device 20500. The thirteenth connecting device 20500 is the same as that shown in FIGS. 30a and 30b except for the following points. Instead of a seal element that surrounds the cap 20502 and forms a seal between the cap 20502 and the inner surface of the needle hub 20011, there is a seal element in the form of a sleeve 20614 that surrounds the needle 20009. The sleeve 20614 extends from the inner wall of the needle hub 20011 (perpendicular to the needle 20009 and located at the tip of the needle hub 20011) to the tip of the cap 20502 and faces the needle 20009. In this way, the sleeve 20614 surrounds the needle 20009 and always maintains both the needle 20009 and the region of the partition wall penetrated by the needle 20009 in a sterilized state.

[0304] When a force in the distal direction is applied to the drug container 20007, the drug container 20007 moves distally with respect to the needle 20009 and the needle hub 20011. As the drug container 20007 advances, the sleeve 20614 collapses outward. Eventually, the needle 20009 penetrates the partition wall and the drug M is discharged through the needle 20009.

[0305] In any of the above embodiments, the sealing element may be formed from a malleable elastomer such as Santroprene. In particular, Santroprene 101-73 can be used.

[0306] In any of the above embodiments, the cap and the needle hub may be formed from a rigid polymer such as polypropylene.

[0307] In any of the above embodiments, the needle may be formed from a metal such as stainless steel (e.g., grade 304 or 316).

[0308] Figure 43 is a flowchart showing a method of manufacturing a connecting device for a syringe for drug administration. This method comprises the following steps. In step 301, a drug container with a cap and sealed by a partition is provided. In step 303, a sealing element that contacts the outer surface of the cap of the drug container is provided. In step 305, a needle for penetrating the partition is provided. The sealing element is installed between the outer surface of the cap of the drug container and the inner surface of the needle hub. In step 307, the needle hub is provided. The connecting device is configured to transition from a first state (where the needle is held away from the partition and the free end of the needle is located in a cavity sealed by the sealing element) to a second state (where the needle penetrates the partition). When the connecting device is in the first state, the seal between the inner surface of the needle hub and the outer surface of the cap is formed by the sealing element. That seal is maintained throughout the transition of the connecting device from the first state to the second state and is also maintained when in the second state.

[0309] The connection device according to the invention disclosed in this specification is mountable on a syringe configured to automatically discharge a single dose of medicine. However, it will be understood that the connection device described in this specification may also be mounted on a manual dosing device or a dosing device equipped with electric drive means. Among the embodiments, there may be at least those in which the connection device and the braking mechanism according to the invention disclosed in this specification are used in the following types of auto-injectors. The medicine container is advanced to discharge a single dose of medicine and automatically retracted into the housing after use.

[0310] The connection device described in this specification may be combined with a power pack and / or a braking mechanism according to the above aspect of the invention and / or with a passive safety shield described in detail below.

[0311] [Passive Needle Prick Prevention Means] This specification also discloses examples of safety devices configured to protect the user from needle pricks before, during, and after use of the syringe.

[0312] Figs. 44a and 44b are cross-sectional views of the tip 1b of the syringe 1001 in the state before injection. The cross-section shown in Fig. 44b is perpendicular to the cross-section shown in Fig. 44a. Fig. 44c is a side view of the syringe of Figs. 44a and 44b.

[0313] As shown in FIGS. 44a and 44b, the safety shield 1019 includes a round tube with a closed tip except for the hole 1400. During injection, the hypodermic needle 1009 extends into the hole 1400. The safety shield 1019 surrounds the tip of the housing 1023. FIGS. 44a - 44c show the safety seal 1019 in a retracted position relative to the housing 1023. The safety shield 1019 can be advanced to a forward position that protects the hypodermic needle 1009 toward the tip side relative to the housing 1023. The forward spring 1025 applies a force to the safety shield 1019 toward the forward position. The forward spring 1025 is located between the housing 1023 and the safety shield 1019. The proximal end of the forward spring 1025 applies a force to a shoulder facing the tip side near the tip of the housing 1023, and the distal end of the forward spring 1025 applies a force to the tip of the safety shield 1019. However, in the pre - injection state shown in FIGS. 44a - 44c, the flexible latch arm 1402 of the housing 1023 catches on the latch surface 1404 of the safety shield 1019, preventing the forward movement of the safety shield 1019. Therefore, in the pre - injection state, the safety shield 1019 cannot advance to the forward position even if the forward spring 1025 acts. That is, the flexible latch arm 1402 and the latch surface 1404 are provided with a releasable locking mechanism. In FIGS. 44a - 44c, this mechanism is in a locked state.

[0314] At the proximal end of the housing 1023, there is a hole 1406 for accommodating the medicine container 1007, and at the distal end, there is a hole 1408 for passing through the subcutaneous injection needle 1009 and the tip of the needle hub 1011 during injection. The medicine container 1007 is accommodated in the housing 1023 and is coupled to the needle hub 1011 and the subcutaneous injection needle 1009. In the state before injection shown in FIGS. 44a-44c, the medicine container 1007, the needle hub 1011, and the subcutaneous injection needle 1009 are in the first position (retracted position). They are configured to move from the first position (retracted position) in the distal direction through the housing 1023 and further to the second position (injection position) during injection. The medicine container 1007, the needle hub 1011, and the subcutaneous injection needle 1009 are subjected to a force toward the first position (retracted position) by the return spring 1021. The return spring 1021 is disposed between the housing 1023 and the medicine container 1007. The proximal end of the return spring 1021 applies a force to the shoulder of the medicine container 1007 facing the distal side. The distal end of the return spring 1021 applies a force to the distal end of the housing 1023. The medicine container 1007 is movable to the second position (injection position) by the action of a plunger rod 1015 (not shown in FIGS. 44a-44c). That is, when the plunger rod 1015 operates, it overcomes the force of the return spring 1021 and advances the medicine container 1007 to the second position (injection position). Since the medicine container 1007 is coupled to the needle hub 1011, when the medicine container 1007 advances toward the second position (injection position), the needle hub 1011 (and the subcutaneous injection needle 1009) also advances toward the second position (injection position), so that the subcutaneous injection needle 1009 pierces the injection site. When the medicine container 1007 further advances toward the second position (injection position), the partition wall 1008 is penetrated by the proximal end of the subcutaneous injection needle 1009. Note that in the state before injection, the subcutaneous injection needle 1009 does not penetrate the partition wall 1008, so the sterilized state of the medicine in the medicine container 1007 is maintained.

[0315] The safety shield 1019 includes a first protrusion 1410 on its inner surface, and the housing 1023 includes a second protrusion 1412 on its outer surface. As shown in Fig. 44a, in the state before injection, the first protrusion 1410 and the second protrusion 1412 are adjacent to each other. Thereby, the safety shield 1019 is prevented from further moving toward the proximal end side relative to the housing 1023 than the shown retracted position. Further, when the safety shield 1019 moves forward to the forward position, the first protrusion 1410 contacts the upright cliff surface 1414a facing the proximal end side of the one-way receiving portion 1414. Therefore, the safety shield 1019 cannot move forward beyond the forward position. In other words, by the installation of the first protrusion 1410, the second protrusion 1412, and the one-way receiving portion 1414, the movement of the safety shield 1019 is restricted between the retracted position and the forward position. Moreover, due to the inclined surface 1414b facing the distal end side of the one-way receiving portion 1414, the first protrusion 1410 can overcome the one-way receiving portion 1414 during the assembly of the distal end portion 1b of the syringe 1001. Since the one-way receiving portion 1414 also includes a cantilevered arm 1416, it is more convenient for the assembly of the distal end portion 1b of the syringe 1001. In short, the distal end portion 1b of the syringe 1001 is easy to assemble, but not easy to disassemble or tamper with.

[0316] As shown in Fig. 44c, the housing 1023 further includes an assembly tab 1418 on the outer surface of the proximal end portion. The assembly tab 1418 is configured to fit into the member of the handle 1003 during the assembly of the syringe 1001. Thereby, the distal end portion 1b is fixed to the proximal end portion 1a.

[0317] Fig. 45a is a first perspective view of the safety shield 1019 shown in Fig. 1, where the inner surface of the safety shield 1019 is visible. Fig. 45b is a second perspective view of the safety shield 1019 shown in Fig. 1, where the tip of the safety shield 1019 is visible. Fig. 45c is a perspective view of the housing 1023 shown in Fig. 1.

[0318] FIG. 45a shows one of the two first protrusions 1410. Although not visible in FIG. 45a, the other first protrusion 1410 faces the visible first protrusion 1410. In other words, the safety shield 1019 has two first protrusions 1410, which are installed one by one on the opposite inner surfaces of the safety shield 1019. As shown in FIG. 45a, the first protrusion 1410 is a protrusion extending circumferentially along a part of the inner circumference of the safety shield 1019. One of the two latch surfaces 1404 is also visible at the tip of the safety shield 1019. Although not visible in FIG. 45a, the other latch surface 1404 faces the visible latch surface 1404. In other words, the safety shield 1019 includes two latch surfaces 1404, which are installed one by one on the opposite edges of the hole 1400. Finally, FIG. 45a shows the longitudinal ridges 1420 formed on the inner surface of the safety shield 1019. When the safety shield 1019 is in the retracted position as shown in FIGS. 44a-44c, each of the longitudinal ridges 1420 fits into the longitudinal groove 1422 of the housing 1023.

[0319] As shown in FIG. 45c, the housing 1023 has a shoulder 1424 facing the tip side. The shoulder 1424 includes a plurality of first locking surfaces 1426 facing the tip side. The first locking surfaces 1426 are arranged at the tips of the grooves 1422. Further, each of the longitudinal ridges 1420 has a second locking surface 1428 facing the base end side. That is, each of the longitudinal ridges 1420 extends from the second locking surface 1428 in the tip direction. When the safety shield 1019 is in the advanced position, since the ridge 1420 is located on the tip side of the groove 1422, the first locking surface 1426 and the second locking surface 1428 face each other.

[0320] FIG. 45c shows two latch arms 1402 of the housing 1023 and one of two one-way receivers 1414. As will be understood by the reader, the other one-way receiver 1414 is installed on the opposite side of the housing 1023 from the visible one-way receiver 1414. The two latch arms 1402 are configured to engage with two latch surfaces 1404. The two one-way receivers 1414 are configured to engage with two circumferential protrusions 1410. Finally, two of four assembly tabs 1418 are visible in FIG. 45c.

[0321] Figure 46 is a side view of the forward spring 1025 in its natural (uncompressed) state. As shown, the forward spring 1025 includes a base end portion 1430 and a tip end portion 1432. The base end portion 1430 has a larger diameter than the tip end portion 1432. When the syringe 1001 is assembled, the forward spring 1025 is disposed between the housing 1023 and the safety shield 1019. The forward spring 1025 is further arranged such that the base end portion 1430 contacts the shoulder 1424 of the housing 1023 and the tip end portion 1432 contacts the tip of the safety shield 1019. Thus, when the safety shield 1019 is in the retracted position shown in FIGS. 44a-44c, the forward spring 1025 is in an axially compressed state and applies a force toward the forward position with respect to the safety shield 1019. Further, when the safety shield 1019 is in the retracted position, the base end portion 1430 of the forward spring 1025 is sandwiched between the ridges 1420 and is thus radially compressed by the ridges 1420. As will be described in more detail later, when the safety shield 1019 is in the forward position, the base end portion 1430 of the forward spring 1025 is no longer sandwiched between the ridges 1420 and is thus not radially compressed. The base end portion 1430 of the forward spring 1025 expands radially and acts as a wedge between the first locking surface 1426 and the second locking surface 1428. Therefore, after the safety shield 1019 reaches the forward position, it cannot return to the retracted position. The one-way receiving portion prevents the safety shield 1019 from further moving toward the tip side from the forward position, and the base end portion 1430 of the forward spring 1025 acts as a wedge between the first locking surface 1426 and the second locking surface 1428 to prevent the safety shield 1019 from moving toward the base end. Thus, the safety shield 1019 becomes immovable from the retracted position.

[0322] FIG. 47a shows the storage state of FIG. 1, FIG. 47b shows the state before injection of FIGS. 2, 44a, 44b, and 44c, FIG. 47c shows the first state during injection, FIG. 47D shows the first state after injection, FIG. 47E shows the second state during injection, and FIG. 47F shows the second state after injection. As will be described later, the second state during injection is the state that appears before the second state after injection.

[0323] As described above, in the storage state of FIG. 1, the cover 1006 surrounds the housing 1023 and the safety shield 1019. This state is the storage state shown in FIG. 47a. When the user prepares for injection, the cover 1006 is removed and the housing 1023 and the safety shield 1019 are exposed. This state before injection is shown in FIG. 47b. When the user operates the drive device 1016 to perform an injection, the medicine container 1007 advances toward the tip side with respect to the needle hub 1011, and penetrates the partition wall 1008 with the subcutaneous injection needle 1009. Thereafter, since the medicine container 1007 and the needle hub 1011 move further in the tip direction, the subcutaneous injection needle 1009 pierces the injection site. This state during injection, that is, the state in which the medicine container 1007 and the needle hub 1011 are in the second position (injection position) is shown in FIG. 47c.

[0324] As can be understood from FIGS. 47a - 47c, since the forward spring 1025 is axially compressed, a force is applied to the safety shield 1019 toward the forward position. However, in FIGS. 47a and 6b, the flexible latch arm 1402 is caught by the latch surface 1404, so that the safety shield 1019 advances to the forward position. In other words, the safety shield 1019 is locked in the retracted position in the storage state and the state before injection, but when the needle hub 1011 moves to the second position (injection position) as in the first state during injection shown in FIG. 47c, the flexible latch arm 1402 disengages from the latch surface 1404. Therefore, the safety shield 1019 is no longer locked in the retracted position.

[0325] When the injection is performed correctly, the drive device 1016 completes its operation and discharges all the medicine from the medicine container 1007. At this time, the drive device 1016 separates from the plunger rod 1015. Therefore, the return spring 1021 (which is compressed in the first state during injection shown in Fig. 47c) returns the medicine container 1007 to the first position (retracted position), thus also retracting the subcutaneous injection needle 1009. When the injection is performed correctly by the user, the syringe 1001 is not removed from the injection site until the injection is completely finished and the medicine container 1007 returns to the first position (retracted position). Therefore, in that case, the latch arm 1402 catches onto the latch surface 1404 again before the syringe 1001 is removed from the injection site. Accordingly, the safety shield 1019 is relocked in the retracted position. In other words, if the injection is completed in the first state after injection (i.e., the correct state) shown in Fig. 47D, the needle 1009 has retracted into the housing 1023 (thus being safe), and the safety shield 1019 is not used. As shown in Fig. 47D, when the medicine container 1007 and the needle hub 1011 move in the proximal direction and return to the first position (retracted position), the first indicator band 1434 moves in the proximal direction together with them. The first indicator band 1434 is located between the medicine container 1007 and the housing 1023 and may be green. Therefore, when the medicine container 1007 and the needle hub 1011 return to the first position (retracted position), the first indicator band 1434 becomes visible through the window portion 1436 of the housing 1023. This enables the user to visually recognize that all of the medicine for one dose has been administered through the needle 1009 and that the medicine container 1007 and the needle hub 1011 have returned to the first position (retracted position) normally.

[0326] On the other hand, if the syringe is to be removed from the injection site earlier than planned, or if a malfunction occurs in the mechanism for retracting the needle, after the syringe 1001 transitions to the second state during injection shown in Fig. 47E, it becomes the second state after injection as shown in Fig. 47F.

[0327] In the second state after injection (i.e., the abnormal state), since the operation of the driving device 1016 was incomplete, only an incomplete dose of medicine was discharged from the medicine container 1007. Or, the driving device 1016 did not separate from the plunger rod 1015. In either case, since the needle hub 1011 did not return to the first position (retracted position), the latch arm 1402 remained in a position where it was not locked. In other words, it would never return to the state where the safety shield 1019 was locked. Therefore, when the syringe 1001 was removed from the injection site, the safety shield 1019 could advance to the forward position. The syringe 1001 temporarily entered the second state during injection shown in Fig. 47E. In this state, although the needle 1009 remained in the second position (injection position), the safety shield 1019 in the forward position prevented injury by the needle 1009. Furthermore, since the proximal end 1430 of the forward spring 1025 wedged between the first locking surface 1426 and the second locking surface 1428, the safety shield 1019 could not return to the retracted position. In short, even if the syringe was not used correctly, the safety shield 1019 kept the syringe safe. As can be seen from Fig. 47E, as the safety shield 1019 advanced, the second indicator band 1438 located on the outer surface of the tip of the housing 1023 became visible. Since the advancement of the safety shield 1019 was the result of abnormal use of the syringe, the visibility of the second indicator band 1438 could easily indicate such abnormal use. The second indicator band 1438 may be red.

[0328] Figure 47F shows the second state (i.e., the abnormal state) after injection. In this state, the driving device 1016 has completed its operation and all the medicine has been discharged from the medicine container 1007. Further, since the driving device 1016 has successfully separated from the plunger rod 1015, the return spring 1021 can return the medicine container 1007 to the first position (retracted position) and retract the needle 1009. However, since the syringe 1001 was removed from the injection site before the medicine container 1007 retreated (as described for the second state during injection shown in Figure 47E), the safety shield 1019 is locked in the forward position. Moreover, even though all the medicine has been discharged through the subcutaneous injection needle 1009, since the syringe 1001 was removed from the injection site earlier than planned, the full dose of medicine has not been completely administered to the injection site. As shown in Figure 47F, both the first indicator band 1434 and the second indicator band 1438 are visible. This indicates not only that the full dose of medicine has been completely discharged through the needle 1009 (since the first indicator band 1434 is visible), but also that as a result of the syringe 1001 being removed from the injection site earlier than planned (since the second indicator band 1438 is visible), the full dose of medicine has not been completely administered to the patient.

[0329] That is, Figures 47D - 47F, 48A - 48C show the following states.

[0330] · The first state after injection. This indicates that the syringe 1001 has been used correctly. In this state, the needle 1009 is in the first position (retracted position) and the safety shield 1019 is in the retracted position. This state is shown in Figure 47D. See also Figure 48A. Figure 48A is an external view of the syringe 1001 in the first state after injection. As shown, the first indicator band 1434 is visible.

[0331] · Second state during injection. Indicates that syringe 1001 has been used improperly and dosing through needle 1009 is incomplete. In this state, needle 1009 is in the injection position and safety shield 1019 is in the forward position. This state is shown in FIG. 47E. See also FIG. 48B. FIG. 48B is an external view of syringe 1001 in the second state during injection. As shown, second indicator band 1438 is visible.

[0332] · Second state after injection. Indicates that syringe 1001 has been used improperly and dosing through needle 1009 was complete but dosing to the injection site was incomplete. In this state, needle 1009 is in the first position (retracted position) and safety shield 1019 is in the forward position. This state is shown in FIG. 47F. See also FIG. 48C. FIG. 48C is an external view of syringe 1001 in the second state after injection. As shown, both first indicator band 1434 and second indicator band 1438 are visible.

[0333] In the rare situation where the mechanism for retracting drug container 1007 fails to operate, the second state during injection may be the third state after injection. This is extremely rare. However, even in that case, the needle 1009 is kept safe by safety shield 1019 being in the forward position.

[0334] Figure 49 shows the method of assembling the syringe 1001 of FIG. 1. In step 401, the forward spring 1025 is installed into the safety shield 1019 and fixed in the longitudinal ridge 1420. Thereafter, the tip of the housing 1023 is inserted into the safety shield 1019, and the forward spring 1025 is installed between the housing 1023 and the safety shield 1019. The housing 1023 is advanced in the safety shield 1019 until the protrusion 1410 overrides the one-way receiving portion 1414. Thereby, the safety shield 1019 does not separate from the housing 1023. When the housing 1023 further advances in the safety shield 1019, the flexible latch arm 1402 catches on the latch surface 1404, so that the safety shield 1019 is locked in the retracted position. While this step is being performed, a tool is inserted into the proximal end of the housing 1023, and the distance between the flexible latch arms 1402 may be expanded while the housing 1023 and the safety shield 1019 are being combined. When the tool is removed after the housing 1023 has been further advanced in the safety shield 1019, the flexible latch arm 1402 catches correctly on the latch surface 1404, so that the safety shield 1019 is locked in the retracted position.

[0335] In step 403, the return spring 1021 is inserted into the housing 1023, and subsequently the medicine container 1007 is inserted. Accordingly, the return spring 1021 is sandwiched between the housing 1023 and the medicine container 1007. When the medicine container 1007 is inserted into the housing 1023, the medicine container 1007 may already be attached to the needle hub 1011 and the hypodermic needle 1009. Further, the needle 1009 may already be covered by the needle shield 1004 and the needle cap 1005.

[0336] As will be understood by the reader, steps 401 and 403 may be in reverse order. That is, step 403 may be performed before step 401. When step 403 is performed first, a tool may not be used to expand the flexible latch arm 1402.

[0337] In step 405, the tip portion 1b assembled in steps 401 - 403 is attached to the handle 1003, and the syringe 1001 is completely assembled.

[0338] This specification discloses a number of embodiments according to the inventions related to each item numbered below.

[0339] A1 A housing having a major axis, - A drive spring installed in the housing, having a tip, a base end on the opposite side of the tip of the drive spring along the major axis, and forming a cavity inside, - A plunger at least partially installed in the medicine container, - A plunger rod fitted to the plunger, - A movement prohibition mechanism and being a syringe or a part of a syringe, wherein the movement prohibition mechanism ○ includes at least one fitting portion at least partially housed in the cavity of the drive spring and configured to releasably fit onto the plunger rod, and the latch mechanism is configured to move toward the tip of the drive spring by the action of the drive spring, ○ and a storage cylinder fitted to the latch mechanism and includes, ○ the latch mechanism is configured to move from a movement prohibition position to a movement permission position with respect to the storage cylinder, - In the movement prohibition position, by keeping the storage cylinder in a state where the fitting portion is fitted onto the plunger rod, the extension of the drive spring moves the latch mechanism and the storage cylinder toward the tip of the drive spring to discharge the medicine from the syringe barrel, - In the movement permission position, by not keeping the storage cylinder in a state where the fitting portion is fitted onto the plunger rod, the fitting portion becomes releasable from the plunger characterizing the syringe or a part of a syringe.

[0340] The syringe according to A1, wherein the latch mechanism includes a tip-side flange that contacts the tip of the driving spring.

[0341] The syringe according to A1 or A2, wherein the latch mechanism and the storage cylinder are configured to move toward the tip of the driving spring in a state connected in the direction of the long axis of the housing when the latch mechanism is in the movement prohibition position.

[0342] A4 The housing includes an adjacent portion, and the adjacent portion prevents the storage cylinder from moving beyond the adjacent portion toward the tip side of the driving spring, thereby making the latch mechanism movable toward the tip side of the driving spring with respect to the storage cylinder and moving the latch mechanism from the movement prohibition position to the movement permission position. The syringe according to A3, which is configured as described above.

[0343] The syringe according to any one of A1 to A4, wherein the latch mechanism is configured to move the storage cylinder toward the tip of the driving spring by an interference fit between the latch mechanism and the storage cylinder in the movement prohibition position.

[0344] The syringe according to A5, wherein the latch mechanism is configured to move from the movement prohibition position to the movement permission position when the force applied by the driving spring overcomes the friction between the latch mechanism and the storage cylinder.

[0345] The syringe according to any one of A1 to A4, wherein the latch mechanism is configured to keep the driving spring in a compressed state before activation of the syringe.

[0346] A8 The latch mechanism includes at least one latching element configured to releasably fix to a part of the housing to keep the driving spring in the compressed state. The syringe according to A7.

[0347] A9 The latch mechanism includes an overhanging portion configured to fit into the driving spring, and a latch fitted into the overhanging portion The syringe according to any one of A1 to A8.

[0348] A10 The syringe according to A9, wherein the latch includes the fitting portion, and the overhanging portion includes the engaging element.

[0349] A11 The syringe according to A10, wherein the latch mechanism is an integrally formed product.

[0350] A12 The syringe further includes a handle, the housing is movable in the axial direction relative to the handle from a non-actuated position to an actuated position, and when the housing moves from the non-actuated position to the actuated position, the driving spring is released from the compressed state. The syringe according to A7.

[0351] A13 The syringe according to A12, wherein when the tip of the syringe is pressed against an injectable tissue, the housing moves from the non-actuated position to the actuated position, and the driving spring is configured to be released from the compressed state.

[0352] A14 The syringe further includes a starting spring installed between the housing and the handle and applying a force to the housing toward the non-actuated position The syringe according to A13.

[0353] A15 The syringe according to A13, wherein when the housing is in the non-actuated position, the engaging element is fixed between the housing and the actuator.

[0354] A16 The syringe according to A15, wherein the entire actuator is installed in the handle.

[0355] A17 The syringe according to A16, wherein the starting tool is fixed to the handle so as not to move in the axial direction.

[0356] A18 The syringe according to any one of A1 to A17, wherein the storage cylinder includes a sleeve having at least one hole.

[0357] A19 When the latch mechanism is in the movement prohibition position, the sleeve of the storage cylinder is aligned with the fitting portion in the radial direction, and the fitting portion is kept fitted to the plunger rod. When the latch mechanism is in the movement permission position, the hole of the sleeve is aligned with the fitting portion in the radial direction, and the fitting portion can be bent outward and detached from the plunger rod. The syringe according to A18.

[0358] A20 The driving spring is 1) a single spring configured to move the syringe barrel axially in the housing and 2) discharge the medicine from the syringe barrel The syringe according to any one of A1 to A19.

[0359] A21 A method for manufacturing a syringe or a part of a syringe, comprising: - preparing a housing having a long axis; - installing a driving spring having a tip and a base end and forming a cavity inside the housing along the long axis with the base end on the opposite side of the tip of the driving spring; - installing at least a part of the plunger in the medicine container; - fitting a plunger rod to the plunger; - fitting a latch mechanism including at least one fitting portion to a storage cylinder to form a movement prohibition mechanism; - Installing at least a part of the latch mechanism inside the cavity of the driving spring, and releasably fitting the fitting portion onto the plunger rod; - Placing the storage cylinder at a movement prohibition position that keeps the storage cylinder in a state where the fitting portion is fitted onto the plunger rod, so that the extension of the driving spring can move the latch mechanism and the storage cylinder toward the tip of the driving spring to enable discharging of the medicine from the syringe barrel; comprising; the storage cylinder is configured to move from the movement prohibition position to a movement permission position where the storage cylinder does not keep the fitting portion fitted onto the plunger rod; A manufacturing method characterized by the above.

[0360] A22 Compressing the tip and the base end of the driving spring to a compressed state, and keeping the driving spring in the compressed state by the latch mechanism; The manufacturing method according to A21, further comprising the above.

[0361] B1 A housing having a major axis, - A driving spring installed inside the housing, - A first driving component configured to transmit power from the driving spring to a plunger installed in a medicine container, - A damper coaxially arranged with respect to the first driving component and fixed so as not to move in the direction of the major axis with respect to the housing; a syringe comprising the above; the first driving component is configured to move along the major axis of the housing with respect to the damper by the action of the driving spring; configured as above; the damper is configured to be press-fitted onto the surface of the first driving component while the first driving component moves with respect to the damper; configured as above; A syringe or a part of a syringe characterized by the above.

[0362] B2. The syringe according to B1, wherein the damper is annular.

[0363] B3. The syringe according to B1 or B2, wherein the driving spring is configured to move the medicine container forward from the retracted position to the extended position with respect to the housing.

[0364] B4. The syringe according to B3, wherein the damper is attached to the housing by a pin extending in the direction of the major axis.

[0365] B5. The tip of the damper forms a socket configured to receive the head of a tool for fixing the damper to the pin. The syringe according to B4.

[0366] B6. The damper comprises an elongated body fixed in the housing, and the first driving component comprises an inner wall forming a longitudinal hole, and the damper is configured to be received in the longitudinal hole and fit into the inner wall. The syringe according to any one of B1 to B5.

[0367] B7. The syringe according to any one of B1 to B6, wherein the damper further comprises at least one deformable braking member installed on the body.

[0368] B8. The body comprises a head including at least one circumferential groove at the tip, and the groove is configured such that a complementary-shaped portion of the braking member fits therein. The syringe according to B7.

[0369] B9 The diameter of the longitudinal hole varies along the major axis of the housing to at least two different values, such that as the first driving component moves relative to the damper, the degree of interference fit between the first driving component and the damper changes. The syringe according to B6 or B7.

[0370] B10 The syringe according to any one of B7 to B9, wherein the braking member includes a component that is overmolded.

[0371] B11 The syringe according to any one of B6 to B10, wherein the inner wall of the first driving component is provided with a plurality of grooves extending longitudinally along the inner wall, along the major axis of the housing, or parallel to the major axis.

[0372] B12 The syringe according to B11, wherein the grooves include at least one groove of a first length and at least one groove of a second length different from the first length.

[0373] B13 The syringe according to B11 or B12, wherein the grooves are circumferentially spaced around the major axis of the housing.

[0374] B14 The syringe according to any one of B10 to B13, wherein the proportion of the grooves in the inner wall of the first driving component decreases towards the tip.

[0375] B15 A method of manufacturing a syringe or a part of a syringe, comprising the following steps. Preparing a housing having a major axis. Attaching a damper to the housing and fixing it so as not to translate along the major axis with respect to the housing. Installing a driving spring in the housing. Installing a first driving component in the housing and coaxially arranging the damper in the first driving component. The first driving component is configured to be moved along the long axis of the housing with respect to the damper by the driving spring while being in a press fit state with the damper.

[0376] B16 The damper includes an elongated main body and a deformable braking member, The method according to B15, further comprising the step of overmolding the braking member on the main body to form the damper. as described in B15 which further comprises.

[0377] C1 A mechanism used in a syringe for drug administration, a container containing a drug, having a cap and sealed by a partition wall, a sealing element in contact with the outer surface of the cap of the container, a needle for piercing the partition wall, a needle hub attached to the needle and comprising, the sealing element is installed between the outer surface of the cap of the container and the inner surface of the needle hub, the mechanism is configured to transition from a first state to a second state, in the first state, the needle is separated from the partition wall, and the free end of the needle is located in a cavity sealed by the sealing element, in the second state, the needle penetrates the partition wall, the seal between the inner surface of the needle hub and the outer surface of the cap is formed by the sealing element in the first state and is maintained both during the transition from the first state to the second state and in the second state. A mechanism characterized by this.

[0378] C2 A housing having a long axis and a tip with a hole through which a part of the needle passes, the housing being configured to accommodate a container containing a drug, A safety shield that surrounds at least the tip of the housing and is configured to move from a retracted position to a forward position covering the needle toward the tip side with respect to the housing. A forward spring disposed between the housing and the safety shield and configured to move the safety shield from the retracted position to the forward position. The mechanism according to C1, comprising the above.

[0379] C3 A releasable locking mechanism configured to lock the safety shield in the retracted position by being fitted into the safety shield. The mechanism according to C2, further comprising the above.

[0380] C4 The needle hub is movable between a first position away from the hole of the housing and a second position extending through the hole of the housing with respect to the housing, and is configured to release the safety shield by disengaging from the locking mechanism at the second position. The mechanism according to C3.

[0381] C5 The locking mechanism includes a latch surface connected to one of the safety shield and the housing and a flexible latch arm connected to the other, the latch arm is configured to lock the safety shield in the retracted position by fitting into the latch surface, and the needle hub is configured to disengage the latch arm from the latch surface at the second position. The mechanism according to C3 or C4.

[0382] C6 The forward spring is configured to prevent the safety shield from returning to the retracted position by being locked to the housing and the safety shield when the safety shield is in the forward position. The mechanism according to any one of C2 to C5.

[0383] The mechanism according to any one of C1 to C6, wherein the sealing element is chemically bonded to the outer surface of the cap.

[0384] The mechanism according to any one of C1 to C7, wherein the sealing element is overmolded on the outer surface of the cap.

[0385] The mechanism according to any one of C1 to C6, wherein the sealing element is an O-ring.

[0386] C10 The sealing element includes a first material, the cap includes a second material different from the first material, and the sealing element and the cap are integrally formed as a single molded product by double injection molding. The mechanism according to any one of C1 to C7.

[0387] C11 The needle hub has a first inner surface that extends perpendicular to the needle and faces the cap, a proximal-side protrusion that extends inward toward the needle, and a second inner surface that extends parallel to the needle from the first inner surface to the proximal-side protrusion. and the second inner surface is configured to fit into the sealing element in the first state, during the transition period from the first state to the second state, and in the second state. The mechanism according to any one of C1 to C10.

[0388] C12 The cap includes a first rib and a second rib, and the sealing element is disposed between the first rib and the second rib. The mechanism according to any one of C1 to C11.

[0389] In the first state, the distance between the first rib and the free end of the needle is closer than the distance between the second rib and the free end of the needle, and the proximal-side protrusion of the needle hub is fitted into the second rib of the cap. In the second state, the first inner surface of the needle hub is fitted into the first rib of the cap. The mechanism according to C12.

[0390] C14 The cap has a first recess for positioning in which the sealing element is installed, and in the second state, a second recess for positioning that accommodates the positioning protrusion of the needle hub according to the selection The mechanism according to any one of C1 to C13, including.

[0391] C15 In the first state, the surface of the positioning protrusion of the needle hub is in contact with the sealing element, the mechanism according to C14.

[0392] C16 A method for manufacturing a mechanism used in a syringe for drug administration, comprising the step of preparing the following. a container with a cap and sealed by a partition wall, and a sealing element in contact with the outer surface of the cap of the container, and a needle for penetrating the partition wall and a needle hub in which the sealing element is installed between the outer surface of the cap of the container and its inner surface. The mechanism is configured to transition from a first state to a second state, in the first state, the needle is separated from the partition wall, and the free end of the needle is located in a cavity sealed by the sealing element, in the second state, the needle penetrates the partition wall, The seal between the inner surface of the needle hub and the outer surface of the cap is formed by the sealing element in the first state and is maintained in the transition from the first state to the second state and also in the second state.

[0393] Step of preparing a housing having a long axis; Step of preparing a safety shield that surrounds at least the tip of the housing and is movable from a retracted position to a forward position for protecting the needle toward the tip side with respect to the housing; Step of disposing a forward spring configured to advance the safety shield between the housing and the safety shield; The method for manufacturing the mechanism according to C16, further comprising:

[0394] C18 A releasable locking mechanism configured to lock the safety shield in the retracted position when fitted to the safety shield; The method for manufacturing the mechanism according to C16 or C17, comprising the step of preparing:

[0395] C19 The needle hub is movable between a first position away from the hole of the housing and a second position extending into the hole of the housing with respect to the housing, and in the second position, it is configured to release the safety shield by being disengaged from the locking mechanism. The method for manufacturing the mechanism according to C18; C18

[0396] C20 The locking mechanism includes a latch surface connected to one of the safety shield and the housing and a flexible latch arm connected to the other, the latch arm is configured to lock the safety shield in the retracted position by fitting into the latch surface, and the needle hub is configured to disengage the latch arm from the latch surface in the second position. The method for manufacturing the mechanism according to C18 or C19;

[0397] The forward spring is configured to prevent the safety shield from returning to the retracted position by being locked between the housing and the safety shield when the safety shield is in the forward position, and is a method for manufacturing the mechanism according to any one of C17 to C20.

[0398] The step of preparing the seal element includes the step of chemically bonding the seal element to the outer surface of the cap, and is a method for manufacturing the mechanism according to any one of C16 to C21.

[0399] The step of preparing the seal element includes the step of overmolding the seal element onto the outer surface of the cap, and is a method for manufacturing the mechanism according to any one of C16 to C22.

[0400] The seal element includes a first material, and the cap includes a second material different from the first material, and is a method for manufacturing the mechanism according to any one of C16 to C23.

[0401] The step of chemically bonding includes the step of performing double injection molding, and is a method for manufacturing the mechanism according to C22.

[0402] The seal element is an O-ring, and is a method for manufacturing the mechanism according to any one of C16 to C21 or C24.

[0403] A housing configured to accommodate a medicine container containing medicine, having a long axis, and having a hole at the tip for passing a part of a needle operably coupled to the medicine container, and A safety shield that surrounds at least the tip of the housing and is configured to move forward from a retracted position to a forward position that protects the needle with respect to the housing toward the tip side, and A forward spring that is disposed between the housing and the safety shield, is configured to advance the safety shield from the retracted position to the advanced position, and prevents the safety shield from returning to the retracted position by being locked to the housing and the safety shield when the safety shield is in the advanced position, and A syringe, or a part of a syringe, comprising the same.

[0404] D2 The housing includes a first locking surface, and the safety shield includes a second locking surface. The second locking surface is disposed to face the first locking surface when the safety shield is in the advanced position. The forward spring is configured to prevent the safety shield from returning to the retracted position by being locked to the first locking surface and the second locking surface when the safety shield is in the advanced position. The syringe according to D1.

[0405] D3 The first locking surface includes a shoulder facing the distal end side of the housing. The second locking surface includes a shoulder facing the proximal end side of the housing, and ridges extending in the direction of the major axis extend from the shoulder in the distal direction. The ridges in the direction of the major axis are configured to radially compress the forward spring when the safety shield is in the retracted position. The forward spring is configured to expand radially when it passes through the second locking surface while the safety shield is advancing. The syringe according to D2.

[0406] D4 The forward spring includes a base end portion having a first diameter and a tip end portion having a second diameter smaller than the first diameter. The base end portion is configured to be locked to the housing and the safety shield when the safety shield is in the advanced position. The syringe according to any one of D1 to D3.

[0407] D5 When the safety shield is in the retracted position, the proximal end portion of the forward spring is compressed to a third diameter that is narrower than the first diameter, and when the safety shield is in the advanced position, the forward spring is arranged to expand to the first diameter. The syringe according to D4.

[0408] D6 One of the housing and the safety shield includes a retaining tab, and the other includes a one-way receiving portion, and the retaining tab is configured to slide over the one-way receiving portion during assembly of the syringe and to contact the one-way receiving portion during advancement of the safety shield, thereby preventing the safety shield from separating from the housing. The syringe according to any one of D1 to D3.

[0409] D7 The one-way receiving portion includes, a slope arranged to facilitate the retaining tab passing over the one-way receiving portion during assembly of the syringe, and a vertical cliff surface arranged to prevent the retaining tab from passing over the one-way receiving portion during advancement of the safety shield and includes. The syringe according to D6.

[0410] D8 The syringe according to D7, wherein the one-way receiving portion further includes a cantilevered arm.

[0411] D9 The syringe according to any one of D6 to D8, wherein the housing includes the one-way receiving portion and the safety shield includes the retaining tab.

[0412] D10 The syringe according to D9, wherein the retaining tab includes a protrusion that extends in the circumferential direction.

[0413] A releasable locking mechanism configured to lock the safety shield in the retracted position when fitted to the safety shield The syringe according to any one of D1 to D10, further comprising

[0414] D12 A needle hub coupled to the needle and the drug container further comprising wherein the needle hub is movable between a first position away from the hole in the housing, and a second position extending into the hole in the housing and is configured such that the needle hub releases the safety shield by disengaging from the locking mechanism in the second position The syringe according to D11

[0415] D13 The locking mechanism includes a latch surface connected to one of the safety shield and the housing, and a flexible latch arm connected to the other, wherein the latch arm is configured to lock the safety shield in the retracted position by fitting into the latch surface and the needle hub is configured to disengage the latch arm from the latch surface in the second position The syringe according to D12

[0416] D14 A return spring arranged to apply a force towards the first position to the drug container and the needle hub The syringe according to any one of D11 to D13, further comprising

[0417] D15 The syringe according to D14, wherein the return spring includes a coil spring and is located between the housing and the drug container

[0418] D16 The syringe according to any one of D1 to D15, wherein the forward spring includes a coil spring ​

[0419] A method for manufacturing a D17 syringe, comprising: providing a housing having a major axis; providing a safety shield that surrounds at least the tip of the housing and is movable from a retracted position to a forward position that protects the needle toward the tip side with respect to the housing; disposing a forward spring between the housing and the safety shield and configuring the forward spring to advance the safety shield; and the forward spring is configured to prevent the safety shield from returning to the retracted position by being locked between the housing and the safety shield when the safety shield is in the forward position. A method characterized by the above.

[0420] D18 One of the housing and the safety shield includes a retaining tab, and the other includes a one-way receiving portion. The method according to D17, further comprising sliding the safety shield on the housing toward the retracted position, allowing the retaining tab to cross the one-way receiving portion, and locking the safety shield behind the one-way receiving portion to prevent the safety shield from being separated from the housing.

[0421]

[0421] D19 The method according to D18, further comprising disposing the forward spring into the safety shield before sliding the safety shield on the housing.

[0422] A housing configured to accommodate a drug container containing a drug, the housing having a major axis and having a hole at the tip for passing a part of a needle operably coupled to the drug container; - It is installed inside the housing, has a tip and a base end located on the opposite side of the tip along the long axis of the housing, and forms a cavity inside, which is a driving spring, - A plunger with at least a part installed in the medicine container, - A plunger rod fitted to the plunger is a syringe equipped with a movement prohibition mechanism, a braking mechanism, a safety shield mechanism, a medicine container connection device and further includes one or more of a) The movement prohibition mechanism includes at least one fitting portion that is at least partially accommodated in the cavity of the driving spring and is configured to be releasably fitted to the plunger rod, and a latch mechanism configured to move in the tip direction by the action of the driving spring, a storage cylinder fitted to the latch mechanism and includes the latch mechanism is configured to move from a movement prohibition position to a movement permission position with respect to the storage cylinder, at the movement prohibition position, the storage cylinder holds the fitting portion of the latch mechanism in a state of being fitted to the plunger rod, and the extension of the driving spring moves the latch mechanism and the storage cylinder in the tip direction to discharge the medicine from the syringe barrel, at the movement permission position, the storage cylinder does not hold the fitting portion of the latch mechanism in a state of being fitted to the plunger rod, so the fitting portion can be removed from the plunger, b) The braking mechanism is provided as the plunger rod as needed, and is a first driving component configured to transmit power from the driving spring to the plunger installed in the medicine container, a damper coaxially arranged with the first driving component and fixed so as not to move in the long axis direction with respect to the housing and includes The first driving component is configured to move along the long axis of the housing with respect to the damper by the action of the driving spring. The damper is configured to be press-fitted onto the surface of the first driving component while the first driving component moves with respect to the damper. c) The safety shield mechanism includes a safety shield that surrounds at least the tip of the housing and is configured to move from a retracted position to a forward position that protects the needle toward the tip side with respect to the housing. a forward spring that is disposed between the housing and the safety shield and is configured to move the safety shield from the retracted position to the forward position. and the forward spring is configured such that when the safety shield is in the forward position, it is locked between the housing and the safety shield so as not to return the safety shield to the retracted position. d) The medicine container connecting device includes a medicine container that contains the medicine, has a cap, and is sealed by a partition wall, a seal element that contacts the outer surface of the cap of the medicine container, a needle for penetrating the partition wall, and a needle hub to which the needle is attached and in which the seal element is installed between the inner surface and the outer surface of the cap of the medicine container. and the medicine container connecting device is configured to shift from a first state to a second state. In the first state, the needle is separated from the partition wall and the free end of the needle is positioned in a cavity sealed by the seal element. In the second state, the needle penetrates the partition wall. The seal between the inner surface of the needle hub and the outer surface of the cap is formed by the seal element in the first state, is maintained during the shift from the first state to the second state, and is also maintained in the second state. A syringe characterized by the above.

[0423] The terms "proximal direction" and "distal direction" are used for convenience in the interpretation of the drawings and should not be construed as limiting the invention. The term "distal direction" means the direction toward the injection site (i.e., the tip of the needle for contacting the patient at the injection site), and the term "proximal direction" means the direction away from the injection site. The term "comprising" should be construed to mean "including but not limited to" and does not exclude the presence of members not recited. When the term "annular" is used, it should not be construed as being limited only to circular, but should be construed to mean any shape with an unbroken circumference. The term "in the direction of the major axis" should be construed to mean along the axis on which the needle is disposed. Similarly, the "radial direction" means a direction perpendicular to the major axis of the needle. The outer peripheral direction means the direction away from the needle, and the inner peripheral direction should be construed as the direction toward the needle.

[0424] The embodiments described above and shown in the accompanying drawings are given as examples in which the invention is effective and are not intended to limit the scope of the invention. Without departing from the invention disclosed in this specification, it is also possible to make changes to the embodiments, replace the components of the embodiments with functionally and structurally equivalent ones, or combine the configurations of different embodiments.

Claims

1. A housing configured to relatively movably accommodate a medicine container containing medicine between a retracted position and an injection position, having a major axis, and having a hole at a tip for passing a part of a needle operably coupled to the medicine container, A return spring disposed between the medicine container and the housing and configured to retract the medicine container from the injection position to the retracted position with respect to the housing, A power pack configured to move the medicine container from the retracted position to the injection position against the force of the return spring and to release the medicine container at the injection position when one dose of medicine from the medicine container is completed, A safety shield surrounding at least the tip of the housing and configured to advance from the retracted position to a forward position on the tip side with respect to the housing to protect the needle, A forward spring disposed between the housing and the safety shield and configured to advance the safety shield from the retracted position to the forward position and to prevent the safety shield from returning to the retracted position by being locked between the housing and the safety shield when the safety shield is in the forward position A syringe comprising the above.

2. The housing has a first locking surface, and the safety shield has a second locking surface, The second locking surface is disposed to face the first locking surface when the safety shield is in the forward position, The forward spring is configured to prevent the safety shield from returning to the retracted position by being locked between the first locking surface and the second locking surface when the safety shield is in the forward position, The syringe according to Claim 1.

3. The first locking surface includes a shoulder facing the tip side of the housing, The second locking surface includes a surface facing the base end side of the housing, and a ridge in the direction of the major axis extends from the surface in the tip direction, The ridge in the direction of the major axis is configured to radially compress the forward spring when the safety shield is in the retracted position, The forward spring is configured to expand radially when passing through the second locking surface while the safety shield is advancing, The syringe according to Claim 2.

4. The forward spring has a base end portion that is a first diameter in the non-compressed state and a tip end portion that is a second diameter narrower than the first diameter in the non-compressed state, The base end portion is configured to be locked to the housing and the safety shield when the safety shield is in the forward position. The syringe according to claim 1.

5. When the safety shield is in the retracted position, the base end portion of the forward spring is compressed to a third diameter narrower than the first diameter. When the safety shield is in the forward position, the forward spring is arranged to expand to the first diameter. The syringe according to claim 4.

6. One of the housing and the safety shield includes a retaining tab, and the other includes a one-way receiving portion. The retaining tab During the assembly of the syringe, slides over the one-way receiving portion. During the forward movement of the safety shield, by contacting the one-way receiving portion, prevents the safety shield from separating from the housing. It is configured as follows. The syringe according to claim 1.

7. The one-way receiving portion During the assembly of the syringe, is arranged with an inclined surface that is convenient for the one-way receiving portion to overcome the retaining tab, During the forward movement of the safety shield, is arranged with a vertical cliff surface that prevents the one-way receiving portion from overcoming the retaining tab. including The syringe according to claim 6.

8. The syringe according to claim 7, wherein the one-way receiving portion further includes a cantilevered arm.

9. The syringe according to claim 6, wherein the housing includes the one-way receiving portion and the safety shield includes the retaining tab.

10. The syringe according to claim 9, wherein the retaining tab includes a protrusion that extends in the circumferential direction.

11. A releasable locking mechanism configured to lock the safety shield in the retracted position when fitted to the safety shield. The syringe according to claim 1, further comprising.

12. A needle hub coupled to the needle and the drug container. further comprising The needle hub is relative to the housing. A first position away from the hole in the housing, A second position extending into the hole in the housing. is movable between The needle hub is configured to release the safety shield by disengaging from the locking mechanism in the second position. The syringe according to claim 11.

13. The locking mechanism includes a latch surface connected to one of the safety shield and the housing, and a flexible latch arm connected to the other, wherein the latch arm is configured to lock the safety shield in the retracted position by fitting into the latch surface, and the needle hub is configured to disengage the latch arm from the latch surface in the second position. The syringe according to claim 12. **Claim 14** A return spring arranged to apply a force to the medicine container and the needle hub toward the first position, the syringe according to claim 12, further comprising. **Claim 15** The syringe according to claim 14, wherein the return spring includes a coil spring and is located between the housing and the medicine container. **Claim 16** The syringe according to claim 1, wherein the forward spring includes a coil spring.

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