Auto-injectors

Abstract

An auto-injector for receiving and activating a syringe includes a housing for receiving the syringe. The housing includes a body and a door movable between a first position and a second position. The syringe is receivable within the housing when the door is in the first position. The auto-injector includes at least one biasing device configured to bias the door from the first position toward the second position or from the second position toward the first position. The auto-injector includes a plunger driver configured to drive a plunger forward within the auto-injector upon activation of the auto-injector to activate the syringe received within the auto-injector, the plunger driver further configured to prime when the door is moved in the direction biased by the biasing device.

Description

[Technical Field]

[0001] The present invention relates to an auto-injector for use with a syringe. The present invention relates to a safety auto-injector and / or an auto-injector for use with a safety syringe, but need not be limited thereto. [Background technology]

[0002] Safety syringes typically have some form of safety mechanism to protect medical personnel from the hypodermic needle of the syringe after it has been injected into a patient. Exemplary safety syringes may have a sheath to cover the needle after use of the syringe. Other exemplary syringes may have a retractable needle within the syringe barrel.

[0003] Safety syringes are broadly divided into "active" and "passive" safety syringes. Active safety syringes typically require some action by the syringe user to engage the safety mechanism and / or deploy the sheath. This action may occur after or when the needle is removed from the patient. Passive safety syringes typically engage the safety mechanism and / or deploy the sheath without any specific action by the user, i.e., no action beyond that normally taken to use the syringe.

[0004] An auto-injector is a device for receiving a syringe and driving the syringe plunger of the syringe into the syringe barrel without the application of force by the user. Typically, an auto-injector has a plunger driver and a drive spring arranged to provide the force to drive the syringe plunger into the barrel. The drive spring and plunger driver may be activated by activation of a button or other release mechanism on the auto-injector. A safety auto-injector may have a shroud that can be deployed into a position covering the needle of a syringe received within the auto-injector before or after use of the syringe. The auto-injector shroud can be deployed under force applied by the shroud spring.

[0005] The force exerted by the drive spring typically depends on the viscosity of the medication in the barrel. The more viscous the medication, the greater the force that the drive spring must exert during firing. Thus, manual priming of an auto-injector with a high force drive spring can be difficult if the force required to prime is too high for a typical auto-injector user. Summary of the Invention [Problem to be solved by the invention]

[0006] There is a need for improved auto-injectors and methods for priming. [Means for solving the problem]

[0007] According to an aspect of the present invention, there is provided an auto-injector for receiving and activating a syringe, the auto-injector comprising: a housing for receiving the syringe, the syringe having a body and a door movable between a first position and a second position, the syringe being receivable within the housing when the door is in the first position; at least one biasing device configured to bias the door from the first position towards the second position or from the second position towards the first position; and a plunger driver configured to drive a plunger forward within the auto-injector upon actuation of the auto-injector to actuate the syringe received within the auto-injector, the plunger driver further configured to prime when the door is moved in a direction in which the biasing device biases the door.

[0008] The biasing device assists the user in priming the automatic injection device by providing an auxiliary force.

[0009] Optionally, the plunger driver includes one or more first springs.

[0010] Optionally, any or each of the one or more first springs comprises a tension spring.

[0011] Optionally, the biasing device comprises one or more second springs.

[0012] Optionally, the body and the door are hingedly connected, and the automatic injector includes a fill link between the body and the door, the connection of the fill link to the body and / or the connection of the fill link to the door being a slidable connection configured to slide when the door moves between the first and second positions, and the fill link configured to couple to a plunger driver for priming during movement of the door.

[0013] Optionally, any or each of the one or more second springs comprises a torsion spring.

[0014] Optionally, a torsion spring is coupled to the door and the body.

[0015] Optionally, the body and door are configured to twist the torsion spring during an opening or closing operation of the door.

[0016] Optionally, the torsion spring is configured to apply a torque to the door hinge to bias the door.

[0017] Optionally, any or each of the one or more second springs comprises a tension spring and / or a compression spring.

[0018] Optionally, the body and the door are connected by a sliding means, and the automatic injector includes a fill link between the body and the door, the connection of the fill link to the body and / or the connection of the fill link to the door being a slidable connection configured to slide as the door moves between the first position and the second position, and the fill link configured to couple to a plunger driver for priming during movement of the door.

[0019] Optionally, the second position of the door comprises a closed position of the door.

[0020] Optionally, moving the door to the second position comprises closing the door.

[0021] Optionally, the portion of the fill link that connects to the door is fixed in position and the portion of the fill link that connects to the body is slidable.

[0022] Optionally, the connection of the fill link to the door is positioned at a point up to one-half, one-third, or one-quarter of the length of the door from the door hinge.

[0023] Optionally, the connection of the body and the fill link to the door is configured such that the maximum angle between the plane of the body and the fill link is up to 45 degrees during (i) movement of the door to the first position and (ii) movement of the door to the second position.

[0024] Optionally, the drive force of the plunger driver is in the range of 30 Newtons to 50 Newtons.

[0025] Optionally, the fill link includes a shuttle configured to move along the shuttle guide to provide a slidable connection to the body of the fill link.

[0026] Optionally, the shuttle includes a first priming portion coupled to the plunger driver and configured to move along the shuttle guide when the door is moved in a direction opposite to the direction in which the biasing device biases the door.

[0027] Optionally, the body and / or the first priming portion includes a latch configured to hold the first priming portion in a predetermined position after the door is moved in a direction opposite to the direction in which the biasing device biases the door.

[0028] Optionally, the shuttle includes a second priming portion configured to move along the shuttle guide in a direction in which the door is biased to prime with the plunger driver.

[0029] Optionally, the first priming portion and the second priming portion are configured to move together along the shuttle guide when the door moves in a direction opposite to the direction in which the biasing device biases the door, and the first priming portion and the second priming portion are separable such that the second priming portion separates from the first priming portion to move along the shuttle guide when the door moves in the direction in which the door is biased.

[0030] Exemplary embodiments are disclosed herein with reference to the accompanying drawings. [Brief explanation of the drawings]

[0031] [Figure 1a] FIG. 1a shows a perspective view of an auto-injector. [Figure 1b] FIG. 1b shows a perspective view of the auto-injector. [Figure 2a] FIG. 2a shows a close-up view of the actuator of the auto-injector. [Figure 2b] FIG. 2b shows a close-up view of the actuator of the auto-injector. [Figure 3] FIG. 3 shows a perspective view of an auto-injector undergoing priming. [Figure 4a] FIG. 4a shows a perspective view of the auto-injector after priming. [Figure 4b] FIG. 4b shows a perspective view of the auto-injector in operation. [Figure 5a] FIG. 5a shows a perspective view of an auto-injector undergoing priming and firing. [Figure 5b] FIG. 5b shows a perspective view of the auto-injector undergoing priming and firing. [Figure 5c] FIG. 5c shows a perspective view of the auto-injector undergoing priming and firing. [Figure 5d]FIG. 5d shows a perspective view of the auto-injector undergoing priming and firing. DETAILED DESCRIPTION OF THE INVENTION

[0032] In general, disclosed herein are exemplary methods and devices for an auto-injector. The term "auto-injector" is used herein and may be considered to encompass both auto-injectors and safety auto-injectors, where appropriate. Auto-injectors can be configured to accept and actuate standard syringes (i.e., non-safety syringes) and / or safety syringes.

[0033] In the following embodiments, the terms "forward" and "front" refer to the end of the injection device or a component thereof that faces the patient. In other words, the front end of the injection device is the end that is proximal to the injection site during use. Similarly, the term "rear" refers to the non-patient end of the injection device assembly or a component thereof. In other words, the term "rear" means away from or far away from the injection site during use. Furthermore, the term "longitudinal" is used to encompass directions along or parallel to the longitudinal axis of the injection device.

[0034] Features of the exemplary configurations disclosed herein are described as being "coupled" to other features. This term encompasses any coupling, whether one-to-one or in any manner adapted, that results in the coupled features working together in any direction. The term "coupled" also encompasses any one of the following: connection of features to one another, contact of one feature to another, and engagement of one feature with another; such coupling may be direct or indirect, i.e., using a third feature between the two features.

[0035] Generally, the present invention aims to assist a user in priming an auto-injector by using a biasing device that provides an assisting force. A user can prime the plunger driver of an auto-injector by applying a force to the plunger driver. This can be done, for example, by opening or closing the door of the auto-injector. The biasing device can include any mechanism that applies a force in a direction that assists the user when the user applies a force to prime the plunger driver. The biasing device is sometimes referred to as a priming assist or priming assist mechanism. An auto-injector can be considered primed when the plunger driver moves the syringe plunger, thereby placing the auto-injector in a suitable configuration for delivering a medication.

[0036] 1a and 1b show perspective views of an exemplary auto-injector for receiving and activating a syringe (not shown). The exemplary auto-injector is shown in the open position.

[0037] The auto-injector 100 further comprises a housing comprising several components. In the configuration of FIG. 1a, the housing comprises a body 101 and a hinged door 102. The hinged door 102 is operable from an unprimed position to a priming position. The hinged door 102 is in the unprimed position in FIGS. 1a and 1b. That is, in the exemplary configuration of FIGS. 1a and 1b, the open position of the hinged door 102 is the unprimed position, and the closed position is the priming position. In other exemplary configurations, the unprimed position may occur when the hinged door 102 is closed, or may be anywhere between the closed and fully open positions of the hinged door 102. For the remainder of this description, the hinged door 102 is considered open when in the unprimed position.

[0038] A syringe (not shown) is receivable within the housing, for example, within the body 101, when the hinged door 102 is in the non-priming position. The body 101 and the hinged door 102 are connected by a hinge 103. Thus, the door 102 is rotatable relative to the body 101. In Figures 1a and 1b, the hinge is located at the rear end of the body 101 and the hinged door 102. In other configurations, the hinge 103 can be positioned at a location further forward of one or both of the hinged door 102 and the body 101.

[0039] At least one fill link 104 is connected between the body 101 and the hinged door 102. In the example of Figures 1a and 1b, two fill links 104 are shown. The connection 105 of the fill link 104 to the body 101 is a slidable connection configured to slide during movement of the hinged door 102 between an open position and a closed position, and thus between a primed position and a non-primed position. The connection 106 between the hinged door 102 and the fill link 104 is fixed with respect to its position on the hinged door 102. The connection 106 between the fill link 104 and the hinged door 102 is rotatable. Connection 106 is at one point on hinged door 102, such that when hinged door 102 is open, connection 106 is behind hinge 103 and when hinged door 102 is closed, connection 106 is in front of hinge 103, i.e., connection 106 rotates about the hinge during opening and closing of hinged door 102. In other arrangements, connection 106 may be slidable and / or connection 105 may be fixed in position.

[0040] Optionally, the hinged door 102 includes a gripping feature, which in the illustrated example includes an ergonomic handle 107. The gripping feature may include any feature that allows a user greater movement when pulling the hinged door 102 open and / or pushing the hinged door 102 closed. For example, the gripping feature may include any type of handle, lip, flange, or gripping surface for a user to open and / or close the hinged door 102.

[0041] The auto-injector 100 further includes a plunger driver 108. The plunger driver 108 is configured to drive the plunger of a syringe received within the auto-injector 100 forward to dispense fluid from the syringe. In the exemplary configuration shown in FIGS. 1a and 1b, the plunger driver includes at least one spring or other biasing member, which may be a tension spring, a compression spring, or a torsion spring, but in the illustrated example includes a tension spring. The illustrated exemplary plunger driver 108 includes two springs, which in the illustrated example are tension springs.

[0042] The auto-injector 100 further includes at least one biasing device 109 configured to bias the hinged door 102 toward the priming position. As described below, the biasing device 109 assists in priming the plunger driver 108 of the auto-injector 100 by providing an auxiliary force to help the user move the hinged door 102 to the primed position, ready to fire.

[0043] The biasing device 109 may comprise one or more springs, which may be tension, compression, torsion, or other types of springs. In the example of FIGS. 1a and 1b, the biasing device 109 comprises two torsion springs coupled to the hinged door 102 and the body 101 about a hinge 103. Relative movement between the hinged door 102 and the body 101 about the hinge 103 twists the torsion springs during opening and / or closing of the hinged door 102. In the example of FIGS. 1a and 1b, to load a syringe into the auto-injector 100, opening the hinged door 102 primes the torsion springs. The torsion springs 109 are primed when the hinged door 102 is in the non-priming position. The torsion spring acts on the hinged door 102 and provides a torque to bias the hinged door 102 toward the priming position (in this case, the closed position).

[0044] 2a and 2b show close-up views of a torsion spring 109 in a configuration where the biasing device comprises the torsion spring 109 at the hinge 103 between the hinged door 102 and the main body 101. A first end 109a of the torsion spring 109 may be coupled to the hinged door 102. The first end 109a may be coupled by engaging with a pocket or ledge 110a formed in, on, or connected to the hinged door 102. A second end 109b of the torsion spring 109 may be coupled to the main body 101. The second end 109b may be coupled by engaging with a pocket or ledge 110b formed in, on, or connected to the main body 101. The torsion spring 109 comprises a helical structure between the first end 109a and the second end 109b. The opening of the helical structure due to the relative rotation of the first and second ends 109a, 109b stores energy in the torsion spring, which is biased toward tightening the helical structure. In the exemplary arrangement of Figures 2a and 2b, the torsion spring is biased toward closing the hinged door 102, and therefore, toward the primed position.

[0045] 2a and 2b show only one torsion spring, the configuration described above can be replicated for the torsion spring on the opposite side of the auto-injector 100.

[0046] The connection portion 105 is configured to couple to the plunger driver 108 for priming during a priming operation of the hinged door 102. That is, in the example shown in Figures 1a and 1b, when the hinged door is closed, the slidable connection portion 105 slides forward along the body 101, thereby tensioning the tension spring of the plunger driver 108. The plunger driver 108 may include a single spring or multiple springs.

[0047] In the example of FIGS. 1a and 1b, opening the hinged door 102 causes the plunger driver 108 to move rearward without priming. Thus, the opening action of the hinged door 102 allows the syringe to be loaded into the auto-injector 100 before priming. Prior to closing the hinged door 102, one end of the plunger driver's tension spring is held in a predetermined position relative to the body 101. Closing the hinged door 102 pushes the filler link 104 forward via its connection 106. In turn, because the filler link 104 is coupled via a slidable connection 105 to the body 101 and to the opposite end of the tension spring, it slides along the body 101, thereby extending the tension spring of the plunger driver 108, as will be described below in FIG. 3.

[0048] The fill link 104, via connections 105, 106 to the body 101 and hinge door 102, converts the arcuate movement of the hinge door 102 into a linear force (forward in this example) on the plunger driver 108 to prime the door as it opens. The positioning of the connection 106 on the hinge door 102 and / or the length of the fill link 104 determine the level of mechanical advantage provided to the user by this mechanism. Thus, it is easier for the user to prime the plunger driver 108 during a priming operation of the hinge door. The longer the fill link 104 and / or the closer the connection 106 is positioned to the hinge 103, the shallower the maximum angle the fill link 104 forms with the body 101 during a priming operation of the hinge door 102. A shallower angle provides a greater mechanical advantage, allowing the plunger driver 108 to prime more easily. This allows for the use of a higher force spring in plunger driver 108. However, it should be noted that there is a trade-off between having a shallower angle to increase the mechanical advantage and having a steeper angle to increase the forward translation of connection portion 105, at the expense of reduced mechanical advantage.

[0049] Thus, in an exemplary configuration, the connection 106 may be positioned, for example, at a point from the hinge of the hinged door 102, for example, half, a third, a quarter, or even a smaller fraction of the length of the hinged door 102.

[0050] In an exemplary configuration, the positions of the body 101, connection 106, and / or hinged door 102 are configured such that the maximum angle between the plane of the body 101 and the filler link 104 is up to 45 degrees during opening and / or closing of the hinged door 102. Typically, the maximum angle of the filler link 104 will be achieved when the hinged door 102 is perpendicular to the body 101. Other maximum angles are possible; for example, the maximum angle may be up to 35 degrees, 25 degrees, or 15 degrees.

[0051] FIG. 3 shows a perspective view of the auto-injector 100 during priming. As described above, the priming action of the hinged door 102 pushes the forward end of the filler link 104 forward via the connection 106 to the filler link 104. The filler link 104 then slides along the body 101 via the slidable connection 105 to the body 101, thereby priming the plunger driver 108. The biasing device 109 is configured to assist in moving the hinged door 102 to the priming position. More specifically, when the hinged door 102 is opened and primed, the torsion spring of the biasing device 109 exerts a rotational force on the hinged door 102, biasing it toward the primed (in this case, closed) position. This assists the user in priming the plunger driver 108. In other words, the torsion spring is configured to store energy delivered by a user when opening the hinged door 102, and then release the stored energy to assist the user in closing the hinged door 102.

[0052] Figure 4a shows a primed view of the underside of the auto-injector 100 with the hinged door 102 in the primed position and the plunger driver 108 primed. The plunger driver 108 is held in the primed state by the fill link 104, whose position is maintained by the primed position of the hinged door 102. In the example of Figure 4a, the two tension springs are fully extended.

[0053] FIG. 4b shows a perspective view of the underside of the auto-injector 100 during actuation. The plunger driver 108 is configured to, upon actuation, drive a plunger forward within the auto-injector 100, thereby actuating a syringe received in the auto-injector 100. In the example of FIG. 4b, multiple tension springs in the plunger driver 108 cooperate to provide the forward force necessary to inject the medication in the attached syringe into a patient. To accomplish this, the plunger can be coupled to the plunger driver 108. In contrast to known devices in which the maximum drive spring strength is typically limited to the force a user can reasonably apply during an unassisted priming operation, the present invention includes a biasing device 109 that provides an assisted force during priming. In this manner, the plunger driver 108 can include a high force spring and, therefore, can provide a higher drive force during actuation. For example, the plunger driver can provide a drive force to the plunger in the range of 30 Newtons to 50 Newtons. In some arrangements, the maximum force a user must apply at any point to prime the plunger driver 108 may be low, for example, in the range of 3 Newtons to 25 Newtons. Preferably, the maximum force a user must apply at any point to prime the plunger driver is between 3 Newtons and 7 Newtons, and more preferably, the maximum force a user must apply at any point to prime the plunger driver is 5 Newtons.

[0054] Further optional features and components will now be described with reference to Figures 1b, 4a and 4b.

[0055] The filler link 104 can be coupled to a shuttle 111. The shuttle 111 can be slidable along the body 101 and configured to move along a shuttle guide 112. A connection 106 can be between the filler link 104 and the shuttle 111 and can be rotatable. In some arrangements, the shuttle 111 provides a slidable connection of the filler link 104 to the body 101.

[0056] Shuttle 111 includes first priming portion 113 and second priming portion 114. A tension spring of plunger driver 108 is connected between first priming portion 113 and second priming portion 114. First priming portion 113 and second priming portion 114 are configured to move together along shuttle guide 112 toward hinge 103 upon opening of hinged door 102. Because the tension spring is connected between the first priming portion and second priming portion, this movement does not prime plunger driver 108.

[0057] Body 101 and / or first priming portion 113 may include a latch configured to hold first priming portion 113 in position on shuttle guide 112 after hinged door 102 is opened. First priming portion 113 and second priming portion 114 are separable after hinged door 102 is opened. Second priming portion 114 is configured to move along shuttle guide 112 away from hinge 103 when hinged door 102 is closed. A tension spring is connected between first priming portion 113 and second priming portion 114 such that the tension spring of plunger driver 108 primes as second priming portion 114 moves forward.

[0058] As described above, first priming portion 113 and second priming portion 114 are configured together to move along shuttle guide 112 when hinged door 102 is open, and first priming portion 113 and second priming portion 114 are separable such that second priming portion 114 separates from first priming portion 113 and moves along shuttle guide 112 when hinged door 102 is closed. This separated state is shown in FIG. 4a.

[0059] Upon firing, for example, caused by pressing the front end of the auto-injector 100 against the patient's skin, the first priming portion 113 is released from its latch and moves forward along the shuttle guide 112 under the force of the plunger driver 108. In the example of FIGS. 4a and 4b, a tension spring pulls the first priming portion 113 of the shuttle 111 forward. As shown in FIGS. 4a and 4b, the shuttle guide 112 is coupled to the plunger driver 108 such that its movement follows a path determined by the shuttle guide 112. The first priming portion 113 is coupled to the syringe plunger of the syringe, thus driving the syringe plunger forward within the syringe barrel.

[0060] The auto-injector 100 may also include a shroud that at least partially covers and extends forwardly beyond the forward end of the syringe needle when the syringe is loaded into the auto-injector and prior to use. If present, the shroud may be configured to release a latch and fire the device upon rearward movement, such as caused by pressing the shroud against the patient's skin. Other contemplated firing mechanisms include a side button or a rear button.

[0061] The auto-injector 100 may also include a ratchet operable during the closing of the hinged door 102 to prevent the force applied by the plunger driver 108 from moving the hinged door in an open direction. Referring to FIG. 3 , when the door 102 is moved to the closed position and primed with the plunger driver 108, the plunger driver 108 exerts an opposing force against the closing hinged door 102. If the user does not maintain force on the hinged door 102 while closing before the hinged door 102 is fully closed, the hinged door 102 will return and open. The ratchet prevents this from happening by moving the hinged door 102 in the closed direction but preventing the hinged door 102 from moving in the open direction. The ratchet is configured to be operable only after the user first opens the door so as not to interfere with the user's ability to open the hinged door 102 to load a syringe into the body 101.

[0062] Those skilled in the art will be able to envision other assemblies, auto-injectors, and features thereof without departing from the scope of the appended claims. In particular, it is noted that one or more features included in one or more of the drawings may be integrated into an auto-injector shown in another drawing, as would be understood by one of ordinary skill in the art.

[0063] For example, while the biasing device 109 is described above as including one or more torsion springs around the hinge 103, the biasing device 109 may additionally and / or alternatively include one or more tension springs and / or one or more compression springs. Similar to torsion springs, tension or compression springs can assist a user in priming (e.g., closing) the hinged door 102 by biasing the hinged door 102 toward the primed position. In one example, a first end of a compression spring may be connected to the body 101 behind the shuttle 111. This connection of the first end to the body 101 is fixed in position. A second end is coupled directly or indirectly to the fill link 104, which may include a connection to the shuttle 111. When the hinged door 102 opens, the fill link 104 slides rearward, compressing the compression spring. The compression spring then exerts a force on the fill link 104, urging it toward the front end of the device and thus the hinged door 102 to the primed, closed position. During the priming (e.g., closing) of the hinged door 102, the additional forward force provided by the compression spring reduces the force a user must apply to prime the auto-injector 100. The above configuration may be adapted to accommodate a tension spring by connecting a first end of the spring to the body 101 at a location forward of the shuttle 111. Thus, the tension spring is extended during the opening of the door 102.

[0064] In another example, the auto-injector can be configured such that a biasing device 109, comprising either a torsion spring or one or more tension springs and / or one or more compression springs, biases the door toward an open position. In such a configuration, the priming action of the door is the opening of the door. The plunger driver of such an auto-injector can be affixed to a first end of the auto-injector remote from the hinge. The second priming portion 114 is configured to move along the shuttle guide 112 toward the hinge 103 upon opening of the hinged door 102. This action primes the plunger driver 108 because the tension spring is affixed away from the hinge end. The body 101 and / or the first priming portion 113 can include a latch configured to hold the first priming portion 113 in position on the shuttle guide 112 after the hinged door 102 is opened.

[0065] Upon firing, triggered, for example, by pressing the front end of the auto-injector 100 on the patient's skin, the first priming portion 113 is released from its latch and moves forward along the shuttle guide 112 under the force of the plunger driver 108. As previously described, the tension spring pulls the first priming portion 113 of the shuttle 111 forward. The shuttle guide 112 is coupled to the plunger driver 108 such that its movement follows a path determined by the shuttle guide 112. The first priming portion 113 is coupled to the syringe plunger of the syringe, thus driving the syringe plunger forward into the syringe barrel.

[0066] While the present invention has been described with reference to a hinged door, it will be appreciated that other door configurations are possible. For example, the body and door may have a slidable connection, as shown in the exemplary auto-injector 200 of FIGS. 5a-5d. Such an auto-injector 200 would function similarly to that described above with reference to FIGS. 1-4. The body 201 and door 202 may be connected by any suitable means, for example, a protrusion from the door 202 may be received within the body 201. As in the exemplary configuration of FIGS. 1-4, a fill link may be provided between the body and the door. The fill link may be configured to slide as the door 202 moves between the first and second positions, as shown in the transition between FIGS. 5b and 5c. The fill link may be configured to couple to the plunger driver of the auto-injector 200 to prime the plunger driver during door movement. As in the example of FIGS. 1-4, a biasing device is configured to bias the door from the first position toward the second position or from the second position toward the first position. In either case, the biasing device may comprise a spring, for example a tension spring or a compression spring.

[0067] In the exemplary configuration of FIGS. 5a-5d, the first position of the auto-injector is an open position, and the injector 203 can be loaded into the auto-injector 200 when the auto-injector 200 is in the open position. After the injector 203 is loaded, the door can be moved toward a second position, in this case a closed position. The auto-injector can then be fired by pressing the front end against the surface of the user's skin or by another firing mechanism, such as a button. It is envisioned that the plunger driver of the exemplary auto-injector of FIGS. 5a-5d can be primed upon either or both of the door opening and closing actions, and the biasing device can be configured to assist in priming the plunger driver accordingly. It will be appreciated that the advantages provided by the biasing device as described herein are realized in all of the above configurations. The present disclosure also includes the following inventions. The first aspect is 1. An automatic injector for receiving and activating a syringe, comprising: The auto-injector comprises: a housing for receiving the syringe, the housing comprising a body and a door operable to a first position and a second position, the syringe being receivable within the housing when the door is in the first position; at least one biasing device configured to bias the door from the first position toward the second position or from the second position toward the first position; a plunger driver configured to drive a plunger forward within the auto-injector upon actuation of the auto-injector to actuate a syringe received within the auto-injector, the plunger driver configured to further prime the plunger driver when the door is moved in a direction that biases the door by the biasing device. The second aspect is The auto-injector of the first aspect, wherein the plunger driver comprises one or more first springs. The third aspect is The auto-injector of the second aspect, wherein any or each of the one or more first springs comprises a tension spring. The fourth aspect is The automatic injector according to any one of the first to third aspects, wherein the biasing device includes one or more second springs. The fifth aspect is The automatic injector of any one of the first to fourth aspects, wherein the body and the door are connected by a hinge, and the automatic injector has a filler link between the body and the door, and the connection of the filler link to the body and / or the connection of the filler link to the door is a slidable connection configured to slide when the door moves between the first position and the second position, and the filler link is configured to connect to the plunger driver for priming during movement of the door. The sixth aspect is The automatic injector of the fifth aspect when referring to the fourth aspect, wherein any or each of the one or more second springs comprises a torsion spring. A seventh aspect is The automatic injector of a sixth aspect, wherein the torsion spring is coupled to the door and the body. The eighth aspect is The automatic injector according to a seventh aspect, wherein the body and the door are configured to twist the torsion spring during an opening or closing operation of the door. A ninth aspect is The automatic injector according to any one of the sixth to eighth aspects, wherein the torsion spring is configured to apply a torque to the hinge of the door to bias the door. A tenth aspect is The automatic injector of a fourth aspect, wherein any or each of the one or more second springs comprises a tension spring and / or a compression spring. An eleventh aspect is The automatic injector of a tenth aspect, wherein the body and the door are connected by a sliding means, and the automatic injector has a filling link between the body and the door, and the connection portion of the filling link to the body and / or the connection portion of the filling link to the door is a slidable connection configured to be slidable when the door moves between the first position and the second position, and the filling link is configured to be coupled to the plunger driver for priming during movement of the door. A twelfth aspect is The automatic injector according to any one of the first to eleventh aspects, wherein the second position of the door comprises a closed position of the door. A thirteenth aspect is In the automatic injector according to any one of the first to twelfth aspects, the movement of the door to the second position comprises the closing operation of the door. A fourteenth aspect is This is an automatic injector according to any one of the fifth to ninth or eleventh aspects, or the twelfth or thirteenth aspect when the fifth or eleventh aspect is cited, wherein the connection portion of the filling link to the door is positionally fixed and the connection portion of the filling link to the main body is slidable. A fifteenth aspect is The automatic injector of any one of the fifth to ninth aspects, wherein the connection of the filling link to the door is positioned at a point from the door hinge to a point up to halfway, one-third, or one-quarter of the length of the door. A sixteenth aspect is An automatic injector according to any one of the fifth to ninth aspects, wherein the connection of the body and the filling link to the door is configured such that the maximum angle between the plane of the body and the filling link is a maximum of 45 degrees during (i) movement of the door to the first position and (ii) movement of the door to the second position. A seventeenth aspect is In the automatic injector according to any one of the first to sixteenth aspects, the driving force of the plunger driver is in the range of 30 Newtons to 50 Newtons. The eighteenth aspect is The automatic injector of any one of the fifth to ninth aspects or the eleventh aspect, or the twelfth to seventeenth aspects when referring to the fifth or eleventh aspect, wherein the filling link comprises a shuttle configured to move along a shuttle guide to provide a slidable connection of the filling link to the body. A nineteenth aspect is An automatic injector according to an eighteenth aspect, wherein the shuttle comprises a first priming portion coupled to the plunger driver and configured to move along the shuttle guide when the door is moved in a direction opposite to the direction in which the biasing device biases the door. The twentieth aspect is A nineteenth aspect of the automatic injector, wherein the main body and / or the first priming portion comprises a latch configured to hold the first priming portion in a predetermined position after the door is moved in a direction opposite to the direction in which the biasing device biases the door. A twenty-first aspect is The automatic injector of the 19th or 20th aspect is characterized in that the shuttle comprises a second priming portion configured to move along the shuttle guide in a direction in which the door is biased to prime with the plunger driver. A twenty-second aspect is 21. An automatic injector according to claim 21, wherein the first priming portion and the second priming portion are configured to move together along the shuttle guide when the door moves in a direction opposite to the direction in which the biasing device biases the door, and the first priming portion and the second priming portion are separable such that the second priming portion separates from the first priming portion and moves along the shuttle guide when the door moves in the direction in which the door is biased.

Claims

1. 1. An automatic injector for receiving and activating a syringe, comprising: The auto-injector comprises: a housing for receiving the syringe, the housing comprising a body and a door operable to a first position and a second position, the syringe being receivable within the housing when the door is in the first position; at least one biasing device configured to bias the door from the first position toward the second position or from the second position toward the first position; a plunger driver configured to drive a plunger forward within the auto-injector upon actuation of the auto-injector to actuate a syringe received within the auto-injector, the plunger driver configured to further prime when the door is moved in a direction that biases the door by the biasing device; the body and the door are hingedly connected, the automatic injector further comprising a fill link between the body and the door, the fill link being connected to the body and / or the fill link being a slidable connection configured to slide when the door moves between the first position and the second position, the fill link being configured to couple to the plunger driver for priming during movement of the door; the filler link comprising a shuttle configured to move along a shuttle guide to provide a slidable connection of the filler link to the body; the shuttle comprises a first priming portion coupled to the plunger driver and configured to move along the shuttle guide when the door is moved in a direction opposite to the direction in which the biasing device biases the door.

2. 10. The automatic injector of claim 1, wherein the plunger driver comprises one or more first springs.

3. 3. The automatic injector of claim 2, wherein any or each of the one or more first springs comprises a tension spring.

4. The automatic injector of any one of claims 1 to 3, wherein the biasing device comprises one or more second springs.

5. 5. The automatic injector of claim 4, wherein any or each of the one or more second springs comprises a torsion spring.

6. 6. The automatic injector of claim 5, wherein the torsion spring is coupled to the door and the body.

7. 7. The automatic injector of claim 6, wherein the body and the door are configured to twist the torsion spring during an opening or closing operation of the door.

8. The automatic injector of any one of claims 5 to 7, wherein the torsion spring is configured to apply a torque to the hinge of the door to bias the door.

9. 5. The automatic injector of claim 4, wherein any or each of the one or more second springs comprises a tension spring and / or a compression spring.

10. 10. The automatic injector of claim 9, wherein the body and the door are connected by a sliding means, and the automatic injector has a fill link between the body and the door, and the connection of the fill link to the body and / or the connection of the fill link to the door is a slidable connection configured to be slidable as the door moves between the first position and the second position, and the fill link is configured to couple to the plunger driver for priming during movement of the door.

11. The automatic injector of any one of claims 1 to 10, wherein the second position of the door comprises a closed position of the door.

12. 8. The automatic injector of claim 7, wherein the movement of the door to the second position comprises the closing movement of the door.

13. 13. The automatic injector of any one of claims 5 to 8 or 10, or any of claims 11 to 12 when dependent on claim 10, wherein the connection of the filler link to the door is positionally fixed and the connection of the filler link to the body is slidable.

14. 9. The automatic injector of claim 5, wherein the connection of the filler link to the door is positioned at a point up to halfway, one-third, or one-quarter of the length of the door from the door hinge.

15. 9. The automatic injector of claim 5, wherein the connection of the body and the filler link to the door is configured such that the maximum angle between the plane of the body and the filler link is up to 45 degrees during (i) movement of the door to the first position and (ii) movement of the door to the second position.

16. 16. The automatic injector of any one of claims 1 to 15, wherein the driving force of the plunger driver is in the range of 30 to 50 Newtons.

17. 2. The automatic injector of claim 1, wherein the body and / or the first priming portion comprises a latch configured to hold the first priming portion in a predetermined position after the door is moved in a direction opposite to the direction in which the biasing device biases the door.

18. 20. The automatic injector of claim 1 or 17, wherein the shuttle comprises a second priming portion configured to move along the shuttle guide in a direction in which the door is biased to prime with the plunger driver.

19. 19. The automatic injector of claim 18, wherein the first priming portion and the second priming portion are configured to move together along the shuttle guide when the door moves in a direction opposite to the direction in which the biasing device biases the door, and the first priming portion and the second priming portion are separable such that the second priming portion separates from the first priming portion to move along the shuttle guide when the door moves in the direction in which the door is biased.

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