Device for dosing the administration of an injectable product

Abstract

Device for controlling the dosing of an injectable substance, comprising: a) a housing (1, 5) in which a container (2) for storing the substance is placed; b) a piston (3) which, when moved in the direction of filling, squeezes the substance out of the container (2) through the outlet opening (4) of the container (2); c) a rack (10) having a first row of teeth (11) and a second row of teeth (12) which moves the piston (3) in the direction of dosing; d) a drive member (20) which is movable with respect to the housing (1, 5) in the same direction as and opposite to the direction of filling and which, when moved in the same direction as the direction of dosing, operates the rack (10); and e) a blocking device (6) which, in cooperation with one of the tooth rows (11, 12), prevents the rack (10) from moving in a direction opposite to the direction of the filling relative to the housing (1, 5) and allows the rack (10) to move in a direction corresponding to the direction of the filling.The second set of teeth (12) includes an extended tooth gap (17a) into which a blocking device (7) cooperating with the second set of teeth (12) engages when the rack (10) is in the initial state prior to setting a first dose amount. The second set of teeth (12) includes an extended tooth gap (19a) into which an actuating device (22) cooperating with the second set of teeth (12) engages when the rack (10) is in the initial state prior to setting a first dose amount.

Description

The description is 10 pages long (including 2 pages of illustrations). HU 224 123 B1 d) a drive member (20) which is movable with respect to the housing (1, 5) in the same direction as and opposite to the direction of filling and which, when moved in the same direction as the direction of feeding, operates the rack (10); and e) a blocking device (6) which, in cooperation with one of the tooth rows (11, 12), prevents the rack (10) from moving in a direction opposite to the direction of the filling with respect to the housing (1, 5) and allows the rack (10) to move in a direction consistent with the direction of the filling. The second set of teeth (12) includes an extended tooth gap (17a) into which a blocking device (7) cooperating with the second set of teeth (12) engages when the rack (10) is in its initial state prior to setting a first dose amount. The second set of teeth (12) includes an extended tooth gap (19a) into which an actuator (22) cooperating with the second set of teeth (12) engages when the rack (10) is in its initial state prior to setting a first dose amount. The invention relates to a device for controlling the dosing of injectable substances. The device designated as the subject of the invention is known, for example, from WO 97 / 36626. The device described therein comprises a housing in which a container is formed for the material. The container has a piston, which, when moved in the direction of filling, squeezes the material out of the container through an outlet opening. The piston is moved in the direction of filling by a rack tensioned to the piston. The rack has a row of teeth. The housing also comprises a drive member which can be moved in and against the direction of filling, the drive member moving the rack in the direction of filling. The actuating means of the drive member engage in the teeth of the rack. During movement, only one of the actuating means is tensioned against the back of one of the teeth of the row of teeth.To adjust the amount of material dispensed with one piston stroke, the drive member is manually set to the starting position by moving it against the direction of filling and pulling it back by the amount of the amount to be dispensed, so that the actuator of the drive member slides elastically along the toothed row. The backward movement of the rack is prevented by blocking devices, which ensure that the rack does not move relative to the housing. The blocking devices cooperate with one of the toothed rows of the rack in such a way that they prevent the rack from moving against the direction of filling and, by elastically releasing, they allow the rack to move in the direction of filling. When the rack is moved, the blocking devices do not fit completely into the toothed slots of the toothed row at the same time. Only one blocking device always fits into a toothed slot, while the other is elastically deflected, resting against the side of a tooth. Alternating interlocking during movement in the direction of filling is advantageous in terms of precise and safe dosing control, but in the case of prolonged standstill, problems with dosing accuracy may arise due to material fatigue of the deflecting blocking or actuating devices. The aim of our invention is to provide a device that allows precise dosing of injectable materials to be controlled with great certainty, even in the case of long downtimes. The object of our invention is achieved as set forth in the claims. The device according to the invention for controlling the dosing of an injectable substance, which comprises a container for storing the substance arranged in a housing, a piston which, when moved in the direction of filling, squeezes the substance out of the container through an outlet opening, a rack having a first row of teeth and a second row of teeth which moves the piston in the direction of dosing, a driving member which is movable within the housing in the same direction as and opposite to the direction of filling and which, when moved in the direction of dosing, operates the rack, a blocking device which, in cooperation with one of the rows of teeth, prevents the rack from moving in the opposite direction of filling and allows the rack to move in the same direction as the direction of filling. Preferably, at least two blocking devices are used, which do not simultaneously fully engage in the tooth gaps of the tooth row. Only one of the blocking devices is always engaged in a tooth gap, while the other is flexibly pushed aside so that it rests on the side of a tooth, perpendicular to the direction of filling. In the solution according to the invention, at least one of the at least two rows of teeth of the rack comprises an extended tooth gap into which the locking means cooperating with the row of teeth is inserted when the rack assumes an initial position prior to a first adjustment. The driving member and the rack are in an initial position relative to each other after assembly, until a first adjustment, (i.e. in the initial position, each of the at least two locking means engages in a tooth gap. By maintaining an advantageous alternating engagement for the adjustment, fatigue of the material of the locking means is avoided. Preferably, to prevent displacement, at least two actuators are connected to the drive member, each of which cooperates with one of the tooth rows, such that only one of the at least two actuators is tensioned in the direction of loading against the tooth of the rack when the drive member is moved in the direction of loading, while the other elastically yields on the side of a tooth. The elastic yielding of the actuator enables the drive member to be attached to the rack. HU 224 123 Moving it in the direction opposite to the direction of charge, relative to Β1. In the solution according to the invention, one of the at least two rows of teeth of the rack comprises an extended tooth gap into which the actuator cooperating with that row of teeth fits when the rack assumes the initial position prior to a first adjustment. In this way, fatigue of the material of the actuator is prevented. An extended tooth gap is a tooth gap that is longer in the direction of the filling than the other regularly formed tooth gaps of the tooth row, which are hereinafter referred to as regular tooth gaps. When blocking, a blocking device or, when fitting, an operating device engages in the extended tooth gap over a longer area than in regularly formed tooth gaps of the same depth. The engagement is in any case more complete, compared to the case where the blocking or operating device engages in a regular tooth gap in the starting position. The engagement is called complete engagement when the blocking or operating device engages in the tooth gap directly up to the root of the tooth, or when a blocking or operating device extends into the rack to the same extent as in the blocking or fitting position. It is particularly advantageous in the initial position to provide an extended tooth gap for one of the at least two locking means in the at least two rows of teeth, as well as for one of the at least two actuating means. The extended tooth gap for the locking means and the extended tooth gap for the actuating means can be provided within one row of teeth. However, it is also possible to provide one extended tooth gap in one row of teeth and the other extended tooth gap in the other row of teeth. The toothing of the rack is preferably designed as a sawtooth, where the teeth taper in a wedge-shaped manner in the direction of the filling. The shape of the blocking and operating means is preferably adapted to the tooth design so that their displacement is prevented as little as possible by friction when the rack is moved in the direction of the filling, and movement opposite to the direction of the filling can be safely stopped only by a forced fit. In principle, however, the toothing may also have a different design, provided that it meets the requirements for the possibility of movement in the direction of the filling and the prevention of movement opposite to the direction of the filling. The rows of teeth can be arranged opposite or next to each other on the rack, but in principle they can be arranged in any part of the rack, according to the height difference of the blocking and / or operating devices. However, it is advisable to arrange the operating devices at the same height, and the alternating engagement is achieved by shifting the row of teeth by a fraction of a tooth distance. It is advisable to arrange the blocking devices in a similar manner, at the same height. The actuating means and the blocking means operate in a similar manner to perform the respective function, engaging a tooth ridge of the rack to actuate or block the rack, and allowing the rack to be retracted or advanced by elastic release. The actuating and blocking means may be of the same or different design. To ensure the elastic release, a tongue is formed perpendicular to the direction of movement of the rack. It is also possible to use a cam that can be moved perpendicularly against the elastic return forces. In one embodiment of the invention, the rack has a third row of teeth, in which a third locking device is engaged, such that the third locking device does not engage in the tooth gap of the rack simultaneously with the other at least two locking devices. Preferably, a fourth row of teeth is also formed at the same height on the rack, in which a fourth locking device is engaged. In the solution according to the invention, the third row of teeth - and if there is a fourth row of teeth, then the fourth row of teeth as well - comprises an extended tooth gap, in which the corresponding locking device is engaged in the initial position of the rack. In a preferred embodiment, when a third set of teeth is used, the drive member advantageously comprises a third actuating means. The third actuating means of the drive member does not engage the tooth gap of the rack at the same time as the other two actuating means of the drive member when the rack teeth are tensioned during movement in the direction of filling. The three actuating means are engaged alternately. If a fourth set of teeth is also provided, the drive member advantageously comprises a fourth actuating means. This makes it possible to control the alternating engagement of the blocking and / or actuating means particularly finely and to prevent material fatigue. In one embodiment, the at least two blocking means are connected to at least two rows of teeth of the rack, while the two actuating means of the drive member are connected to two other rows of teeth of the rack. The actuating means and blocking means arranged alternately around the rack thus make it possible to shorten the length of the rack and consequently the length of the device. The blocking means and the actuating means can be formed at the same height with respect to the direction of filling. The alternating connection of the blocking means and the actuating means is ensured in this case as well. The present invention relates to both a dosing device with and without extended teeth. The advantageous embodiments of our invention are described in detail based on the attached figures. Figure 1 shows an injection device comprising a rack with four rows of teeth. Figures 2 and 3 show the rack in detail, with the engagement of the locking and actuating devices. HU 224 123 B1 The injection device comprises a housing consisting of a front housing sleeve and a rear housing sleeve 5 firmly connected thereto. The front housing sleeve 1 is used to receive an ampoule. The ampoule 2 contains a liquid active ingredient, for example insulin. The ampoule 2 also comprises a piston 3. By moving the piston 3 towards the ampoule outlet opening 4, the piston forces the substance in the ampoule through the ampoule outlet opening 4 and into the injection needle N. The front housing sleeve 1 is protected by a cap K. The needle N is also protected by a needle cap. The piston 3 is moved in the direction of filling by a drive device located in the rear housing sleeve 5. The drive device comprises a drive member 20 and a rack 10 which is in direct contact with the piston 3, the driven member. The drive member 20 is arranged in the rear housing sleeve 5 so as to be linearly movable in the direction of filling of the piston 3 and in the opposite direction. To prevent displacement, a cover 25 protrudes from the rear part of the housing in connection with the drive member 20. Connected to the rear housing sleeve 5, to prevent displacement, a sleeve-type dosing member 30 is provided, which is rotatable about a common longitudinal axis. By twisting the dosing member 30, the maximum dose travel distance that the drive member 20 and the rack 10 can cover in the filling direction is set, and thus the maximum amount of material that can be injected during an injection. Therefore, the dosing member 30 has a front sleeve part 31 spirally surrounding it, i.e. the front sleeve part 31 can be gradually adjusted downwards along the circumference with respect to the longitudinal axis of the injection device from a first position. The dosing member 30 can be designed in accordance with the dosing member described in WO 97 / 36625 and can cooperate with the drive member 20 during dosing in the manner described therein. The dosing takes place in the first position of the drive member 20 with respect to the direction of filling, where a collar or cam 26 projecting radially from the outer surface of the drive member 20 comes into contact with the barrier formed in the rear housing sleeve 5. In this first position of the drive member 20, the dosing member 30 is twisted relative to the rear housing sleeve 5 until the position corresponding to the desired dose quantity is reached. At this time, a free dose space is created between another collar or cam 27 projecting similarly from the outer surface of the drive member 20 and the front surface of the dosing member 30 opposite the other collar or cam 27. The drive member 20 can be retracted in the opposite direction of the filling, to an extent corresponding to the dose space, with respect to the rear housing sleeve 5, and thus also with respect to the piston 3. The drive member 20 is retracted by manually pulling the cover 25. The dose space corresponds to the amount of the next dose to be administered. When the drive member 20 is retracted, the rack 10 remains in the slidable position assumed with respect to the housing during feeding. Its movement opposite to the direction of filling is prevented by the blocking means 6 and 8 formed on the rear housing sleeve 5. The blocking means 6 and 8 are locking cams formed at the front end of a resiliently yielding tongue and which extend radially inward from the tongue towards the rack 10. Each of the blocking means 6 and 8 cooperates with a row of teeth of the rack 10 opposite it so as to allow the rack 10 to be moved in the direction of filling and to prevent its movement in the direction opposite to the direction of filling by means of a positive engagement. The rack 10 is a bar with a rectangular cross-section, on all four sides of which a row of saw-tooth-like teeth is formed in the direction of filling. In Figure 2, two rows of teeth, 11 and 13, formed on opposite sides of the rack 10, opposite the blocking devices 6 and . In addition to the two rows of teeth, 11 and 13, the rack 10 also contains two further rows of teeth formed on the other two opposite sides, one of which is shown with the item number 14 in Figure 1. Each of the teeth 15 of the rows of teeth of the rack 10 are wedge-shaped in the direction of filling, in the embodiment according to our example the side of the teeth is an inclined plane. The back of each of the teeth 15 is flat and perpendicular to the direction of filling, i.e. to the longitudinal axis of the injection device and the rack 10. The regular tooth gaps of the tooth row are marked with 16 item numbers. The four rows of teeth have the same tooth spacing. The individual rows of teeth are arranged so that the tooth spacing is offset from each other in the direction of the filling. The offset between the rows of teeth is determined by the 2nd and 3rd We can see it in Figure 3, labeled a, b, and c. The blocking devices 6 and 8, as well as the blocking devices 7 and 8 opposite the tooth rows 12 and 14, cooperating with them, are formed at the same height with respect to the direction of filling, at an angular distance of 90° from each other. Due to the offset between the tooth rows, only one of the blocking devices 6-9 always engages completely in the tooth gap 16 of the opposite tooth row when the rack 10 is moved forward. Each of the other three blocking devices is located on the side of the tooth 15 of the opposite tooth row, tilted away from the rack 10. When the rack 10 is moved in the direction of filling, the blocking devices 6-9 engage completely in the opposite tooth row one after the other, i.e. the blocking devices engage alternately. The elastic engagement of each blocking device in the tooth slots of the rack 10 prevents the rack 10 from moving in a direction opposite to the direction of loading. The rack 10 is moved by the drive member 20 in the direction of the filling. Therefore, the drive member 20 ends in four wedge-shaped tongues in the direction of the filling, from the ends of which locking cams protrude radially inward. The operating means 21 and 23 formed opposite each other can be seen in Figure 1. In the embodiment according to our example, the operating means and the blocking means are similar in shape and function, each being a locking cam formed on a resiliently yielding tongue. When the drive member 20 is moved in the direction of the filling, one of the operating means is tensioned against the back of one of the teeth 15 of the tooth row opposite it, thus forcing the rack 10 to move in the direction of the filling. When the drive member 20 is moved in the opposite direction to the direction of loading, the actuating device is released and the teeth 15 are wedge-shaped. HU 224 123 Due to the design of Β1, the actuator slides along the tooth row of the rack 10 blocked by the blocking device. The actuators are pointed in the direction of the filling and at the same time never engage in the regular tooth slots 16 of the rack 10. In Figures 1-3 the device is shown in its initial state, where the rack 10 is in the rearmost position with respect to the rear housing sleeve 5 and the drive member 20. The rear housing sleeve 5 in the initial state received from the manufacturer is fully equipped with the rack 10 and the drive member 20, including the cover 25 and the dosing member 30. The initial state therefore corresponds to the storage state of the injection device, in particular with respect to the drive means and the dosing means. In our example, the injection device is a disposable pen. However, it can be made reusable by simple modifications, for example by replacing the ampoule. When using the injection device containing 2 ampoules, in the initial state, the user sets the amount to be administered during the first injection. To do this, the dosing member 30 is screwed to the rotation position corresponding to the desired dose amount. In this rotated position, the cam 27 of the drive member 20 forms the free dosage space from the opposite front surface of the dosing member 30. In the initial state, only the blocking device 6 contacts the back of one of the teeth of the tooth row 11. The blocking devices 7, 8 and 9 are in a non-contacting, rest position with respect to the tooth rack 10 before closing, but in the initial position they fit into the extended tooth gap 17a, 17b and 17c, which is longer than the regular tooth gap 16. Of the actuating devices, only the actuating device 21 contacts the back of a tooth in the initial position. The actuators 22, 23 and 24 are in a rest, non-contact position in the tooth slots opposite them, i.e. they are not deflected in the initial state.Each of the tooth rows 12, 13 and 14 contains a tooth in front of the tooth gaps 17a, 17b and 17c. These teeth define the tooth gaps 17a, 17b and 17c in the direction of filling and serve exclusively for the functional testing of the injection device. Immediately after the assembly of the device, the rack 10 is pushed into the starting position by means of the blocking devices 6-9 arranged in a circle around it. The drive member 20 is retracted from its forward position with respect to the rear housing sleeve 5 by manually pulling the cover 25. When the drive member 20 is retracted, the actuating means 21 and 24 slide along the opposite row of teeth of the rack 10, the movement of which is prevented by the blocking means 6. During injection, the driving member 20 and the rack 10 are moved by pressing the cover 25 a distance corresponding to one dose in the direction of filling, the rack 10 thus pushes the piston 3 in the ampoule 2 towards the outlet opening 4 to discharge the material. In the initial position, as shown in the figures, only the operating device 21 is in contact with the back of one of the teeth of the rack 10. In our example, the actuating means of the drive member 20 are arranged behind the blocking means with respect to the direction of loading. The circular arrangement of the blocking means and the actuating means is such that, despite their own elastic restoring force, they can be bent radially outwards from the rack 10 in accordance with the configuration of the teeth in the tooth row of the rack 10. In the embodiment according to our example, each of the blocking means and each of the actuating means is arranged at the same height with respect to the direction of loading, while the tooth rows of the rack 10 are arranged offset relative to each other so that the regular tooth gaps 16 in the tooth row are arranged at different heights with respect to the direction of loading. As a result, only one blocking means or actuating means is always engaged in one of the regular tooth gaps 16.An implementation is also conceivable where the blocking devices and the operating devices are arranged offset from each other, i.e. at different heights with respect to the direction of filling, in which case the tooth rows of the rack 10 are at the same level. The solution we propose is advantageous during production. If the rack 10 is provided with four rows of teeth, the length of the drive means and the metering means can be reduced while maintaining the alternating engagement by arranging all the blocking means and all the actuating means at the same level with respect to the direction of filling. This is achieved by having two blocking means, for example, blocking means 6 and 8, engaged in two of the four rows of teeth of the rack 10, and at the same height, the two actuating means of the drive member 20 engaged in the other two rows of teeth. By arranging the blocking means and the actuating means in pairs, the advantages of the alternating engagement can be maintained by appropriately shifting the rows of teeth or the blocking and actuating means. In the initial position shown in the figures, which is also the storage state, in the case of individual components of the injection device, in particular the rack 10, the drive member 20 and the blocking devices 6-9 arranged in the rear housing sleeve 5, there is a risk of material fatigue in those blocking devices and those actuating devices which do not fit into the tooth gaps 16 in the initial position, i.e. when they are at least partially or, as we have seen in our example, completely independent of them. These blocking devices and actuating devices are bent in the initial position. During the bending, the actuating and blocking devices are elastically distorted. If this state lasts for a long time, we cannot guarantee with complete certainty that they will bend back elastically during operation, i.e. they may not be able to fit onto the back of a tooth. Therefore, the rack 10 includes extended tooth slots into which the blocking means and the actuating means can fit, which do not contact the back of the teeth of the rack 10 when the injection device is in the initial state. Figures 2 and 3 are presented together. On all four sides of the rack 10, starting from the end directly opposite the piston 3, the same HU 224 123 Β1 is formed with a sawtooth-like tooth row of the same shape and with the same tooth spacing. These are the tooth rows 11,12, 13 and 14 in the figures. The first tooth row 11 contains 15 teeth following one another, with regular spacings, without gaps. In the initial position shown in the figures, the blocking device 6 and the actuator device 21 placed behind it fit into a regular tooth gap 16 each, when viewed from the direction of the filling, so that they contact the back of the teeth. Moving in the direction of rotation around the rack 10, the second row of teeth 12 following the first row of teeth 11 is It is shown in Figure 2. The second row of teeth 12 is formed in a similar manner to the first row of teeth 11, except for the following. Firstly, the teeth 15 of the second row of teeth 12 are offset along the rack 10 in the direction of the charge by a fraction of a tooth gap, namely a distance d. This offset, as well as the positioning of the blocking devices 6 and 7 at the same height, results in only one of the blocking devices 6 and 7 being fully engaged at any one time. Secondly, the second row of teeth includes an extended tooth gap 17a around its end facing the piston, into which the blocking device 7 fits in the initial state. Thus, the blocking device 7, which would deviate from the rack 10 in the initial position if the second row of teeth 12 were perfectly regular, fits completely beyond the normal extent of the second row of teeth 12 thanks to the extended tooth gap 17a. In this way, the tongue forming the blocking means 7 is not subject to elastic deflection in the initial state. A further difference is that the second row of teeth 12 includes another extended tooth gap 18a behind the extended tooth gap 17a, as seen from the piston 3. In the initial position, the second actuator 22 of the drive member 20 rests undistorted in this extended tooth gap 18a. The engagement sequence of the actuators 21 and 22 is the same as the engagement sequence of the locking devices 6 and 7. Moving in the direction of rotation around the rack 10, we can see the longitudinal section of the next, third row of teeth 13 in Figure 3. The third row of teeth 13 includes an extended tooth gap 17b and an extended tooth gap 18b, into which the third locking device 8 and the third operating device 23 fit in the rest position, i.e. in the initial state without distortion. Moving in the direction of rotation around the rack 10, the third row of teeth is followed by the fourth row of teeth 14. Similarly to the second row of teeth 12 and the third row of teeth 13, the fourth row of teeth 14 also includes an extended tooth gap 17c and an extended tooth gap 18c, into which the fourth blocking device 9 and the fourth operating device 24 fit in the initial position, without the tongue carrying them being subjected to a distorting effect. The extended teeth 17a, 17b and 17c are formed at the same height, corresponding to the blocking means 7, 8 and 9, for engagement with them in the initial position. The same applies to the extended tooth gaps 18a, 18b and 18c, which are formed at the same height on the rack 10 with respect to the direction of filling. The extended teeth gaps 17a and 18a are formed in different ways. The extended tooth gap 17a is formed by omitting one tooth when the rack 10 is cast into a mold, or by removing one tooth 15 after casting. When forming the extended tooth gap 18a, only a part of a tooth is removed, or a tooth is only partially cast out, so that the second actuator 22 engaging in the extended tooth gap 18a is located closer to the back of the tooth closest to the opposite direction of the filling in the second tooth row 12 than the first actuator 21 is to the back of the tooth closest to the opposite direction of the filling in the first tooth row 11. In the second tooth row 12, the back of the tooth closing the extended tooth gap 18a is closer to the piston 3 than the back of the tooth closing the tooth gap 16 in the first tooth row 11 in the starting position. Thus, when the drive member 20 leaves the starting position to dispense the first dose, the second actuator 22 rests on the back of the tooth in front of the first actuator 21. A detailed drawing of the area around the extended tooth gap 18b of the third tooth row 13 is shown below Figure 3. The extended tooth gap 18b is formed in such a way that the middle one of three consecutive teeth does not protrude as much from the rack as the two regular teeth 15 adjacent to it. The middle tooth 19 is truncated. With this design, the operating device 23 is located in the starting position resting on the side of the tooth 19b, at most slightly bent, preferably without bending. In this way, the back of the truncated tooth 19b is located in the thus formed extended tooth gap 18b, at the height of the rack 10 where a tooth back would be located anyway if all the teeth of the tooth row 13 were designed in a perfectly similar way. The operating device 23 can fit into the extended tooth gap 18b in a length L.For actuators 22 and 24, the extended tooth gaps 18a and 18c are formed in a similar manner to the extended tooth gap 18b, except that the length L is shorter than that of the extended tooth gap 18b. The blocking means 6-9 do not penetrate as far into the tooth gaps 16 as the actuating means 21-24 when they are fully closed to the rack 10. The extended tooth gaps 18a, 18b and 18c can be formed in the same way, simply omitting one tooth, i.e. they can be formed in the same way as the extended tooth gaps formed for the blocking means. The extended tooth gaps 17a, 17b and 17c can be formed by retaining a truncated tooth, preferably in a similar manner to the extended tooth gaps 18a, 18b and 18c. The formation methods HU 224 123 Β1 are interchangeable. However, the implementation of extended tooth gaps for the blocking devices and the operating devices as in our example is the practical solution. In the initial position, the first blocking means 6 prevents the rack 10 from moving in the opposite direction to the direction of filling. In this initial position, the quantity to be dispensed during the next injection is first selected using the dosing member 30 shown in Figure 1. The drive member 20 is then retracted to the extent corresponding to the desired quantity, whereby the actuators 21-24 slide along the teeth 15 of the opposing gear train, and the displacement of the gear trains ensures that the actuators 21-24 engage in regular alternating engagement, resulting in several closing processes taking place within one tooth gap for each actuator. In the rearmost position of the drive member 20 defined by the dosing member 30, it can be guaranteed with much greater certainty that at least one of the actuators 21-24 will engage than in the case where only one gear train and one actuator are used.Accordingly, the same applies to the connection of the tooth rows and the blocking means 6-9. When the drive member 20 is moved against the direction of filling, and likewise when the rack 10 is moved in the direction of filling, the actuating means and the blocking means each engage alternately and each locks into an extended tooth gap in the starting position. Immediately after the starting position, the actuating means 23 cooperates with the third tooth row 13. Due to the simple shape of the extended tooth gaps 17a, 17b and 17c, the blocking means 6 of the blocking means is the first to come into blocking engagement when the rack 10 is moved for the first feed.

Claims

1. Device for controlling the dosing of an injectable substance, comprising: a) a housing (1, 5) in which a container (2) storing the substance is placed; b) a piston (3) which, when moved in the direction of filling, is designed to squeeze the substance out of the container (2) through its outlet opening (4); c) a rack (10) having a first row of teeth (11) and a second row of teeth (12) and moving the piston (3) in the direction of dosing; d) a drive member (20) which is movable relative to the housing (1, 5) in the same direction as and opposite to the direction of filling and which operates the rack (10) when moved in the same direction as the direction of dosing;and e) at least two blocking means (6, 7) cooperating separately with one of the tooth rows (11, 12) and preventing the movement of the rack (10) in the opposite direction to the direction of filling relative to the housing (1, 5) and allowing the movement of the rack (10) in the same direction as the direction of filling by elastic release, which are not simultaneously engaged in the tooth slots (16) of the tooth rows (11, 12) when the rack (10) is moved, characterized in that f) the second tooth row (12) comprises an extended tooth slot (17a) into which the blocking means (7) cooperating with the second tooth row (12) is engaged when the rack (10) is in the initial state prior to setting a first dose amount.; 2. Device according to claim 1, characterized in that a tooth gap, which is formed in the tooth row (12) directly behind the extended tooth gap (17a), when viewed from the piston (3), is the tooth gap (16) of the at least two tooth sets (11, 12) next to which one of the at least two blocking means (6, 7) engages.

3. Device according to claim 1 or 2, characterized in that the rack (10) comprises a third row of teeth (13) to which a third blocking device (8) is connected, and when the rack (10) is moved, the third blocking device (8) does not fully engage in a tooth slot (16) of the rack (10) simultaneously with the other at least two blocking devices (6, 7).

4. Device according to the preceding claim, characterized in that the third row of teeth (13) also comprises an extended tooth gap (17b) in which the third blocking device (8) cooperating with the third row of teeth (13) engages when the rack (10) is in the initial state prior to setting a first dose amount.

5. The device according to claim 3 or 4, characterized in that the rack (10) comprises a fourth row of teeth (14) to which a fourth blocking device (9) is connected, and when the rack (10) is moved, the fourth blocking device (9) does not fully engage in a tooth slot (16) of the rack (10) simultaneously with the other at least two blocking devices (6, 7), and preferably not simultaneously with the third blocking device (8).

6. Device according to the preceding claim, characterized in that the fourth row of teeth (14) also comprises an extended tooth gap (17c), in which a fourth blocking device (9) cooperating with the fourth row of teeth (14) engages when the rack (10) is in the initial state prior to setting a first dose amount.

7. Device for controlling the dosing of an injectable substance, comprising: a) a housing (1, 5) in which a container (2) storing the substance is placed; b) a piston (3) which, when moved in the direction of filling, is designed to squeeze the substance out of the container (2) through its outlet opening (4); c) a rack (10) having a first row of teeth (11) and a second row of teeth (12) and moving the piston (3) in the dosing direction;HU 224 123 Β1 d) a drive member (20) movable in the same direction as and opposite to the direction of the filling relative to the housing (1,5), to which at least two actuating devices (21,22) preventing displacement are connected, each of which is designed to cooperate separately with one of the tooth rows (11,12) so that when the drive member (20) is moved, only one of the at least two actuating devices (21,22) is tensioned against a tooth (15) of the rack (10) in the direction of the filling, while the other is pressed against the side of a tooth with elastic release, the actuating devices (21,22) being designed to enable the movement of the drive member (20) opposite to the direction of the filling with elastic release; e) a blocking device (6) cooperating with one of the tooth rows (11, 12), which is designed to prevent the rack (10) from moving in a direction opposite to the direction of the filling and to allow the rack (10) to move in a direction in line with the direction of the filling, relative to the housing (1, 5);characterized in that f) the second row of teeth (12) comprises an extended tooth gap (19a) into which an actuating means (22) cooperating with the second row of teeth (12) engages when the rack (10) is in an initial state prior to setting a first dose amount.; 8. Device according to the preceding claim, characterized in that a tooth slot (16), which is formed in the tooth row (12) directly behind the extended tooth slot (18a), viewed from the piston (3), is the next tooth slot of the at least two tooth rows (11, 12) in which one of the at least two actuating means (21, 22) is engaged.

9. The device according to any one of the preceding two claims, characterized in that the rack (10) comprises a third row of teeth (13), to which a third actuating means (23) of the driving member (20) is connected such that when the driving member (20) is moved, only one of the actuating means (21, 22, 23) is tensioned against a tooth (15) of the rack (10) in the direction of the filling, and the actuating means (21, 22, 23) are designed to allow the movement of the driving member (20) in the direction opposite to the direction of the filling with elastic release, and the third row of teeth (13) of the rack (10) comprises an extended tooth gap (18b), into which an actuating means (23) cooperating with the third row of teeth (13) is connected when the rack (10) is moved from its starting position. is in condition.

10. The device according to the preceding claim, characterized in that the rack (10) comprises a fourth row of teeth (14), to which a fourth actuating means (24) of the driving member (20) is connected such that when the driving member (20) is moved, only one of the actuating means (21, 22, 23, 24) is tensioned against a tooth (15) of the rack (10) in the direction of the filling, and the actuating means (21, 22, 23, 24) are designed to allow the movement of the driving member (20) in the direction opposite to the direction of the filling with elastic release, and the fourth row of teeth (14) of the rack (10) comprises an extended tooth gap (18c), in which an actuating means (24) cooperating with the fourth row of teeth (14) is connected when the rack is moved. (10) is in the initial state.