Injection Device
First Claim
1. A releasable drive coupling for an injection device comprising:
- a first drive element having a first projecting flexible arm; and
a second drive element capable of sliding relative to the first drive element and having;
a drive surface adapted to receive the first flexible arm, to allow axial loads to be transmitted from one drive element to the other; and
a second projecting flexible arm so positioned relative to the drive surface that inward flexing of the second flexible arm causes it to act upon the first flexible arm and flex the latter to a point at which it is no longer received by the drive surface, at which point the first and second drive elements are free to slide relative to one another and the drive coupling is thus disengaged.
2 Assignments
0 Petitions
Accused Products
Abstract
An injection device (210) is described. A housing (212) receives a syringe and includes a return spring (226) for biasing the syringe from an extended position in which its needle (218) extends from the housing (212) to a retracted position in which the it does not. A drive spring (230) acts on a first drive element (232) and a second drive element (234) acts upon the syringe to advance it from its retracted position to its extended position and discharge its contents through the needle. The first drive element (232) is capable of movement relative to the second (234) once a nominal decoupling position has been reached. A release mechanism is activated when the first drive element (234) is further advanced to a nominal release position, to release the syringe (214) from the action of the drive spring (230), whereupon the return spring (226) restores the syringe (214) to its retracted position. Decoupling of the drive elements is achieved with a particular form of releasable drive coupling using two pairs of overlying flexible arms (235, 247). A particular form of release mechanism that also uses flexible arms (233) is also envisaged.
112 Citations
31 Claims
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1. A releasable drive coupling for an injection device comprising:
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a first drive element having a first projecting flexible arm; and a second drive element capable of sliding relative to the first drive element and having; a drive surface adapted to receive the first flexible arm, to allow axial loads to be transmitted from one drive element to the other; and a second projecting flexible arm so positioned relative to the drive surface that inward flexing of the second flexible arm causes it to act upon the first flexible arm and flex the latter to a point at which it is no longer received by the drive surface, at which point the first and second drive elements are free to slide relative to one another and the drive coupling is thus disengaged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. An injection device comprising:
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a housing adapted to receive a syringe having a discharge nozzle, the housing including means for biasing the syringe from an extended position in which the discharge nozzle extends from the housing to a retracted position in which the discharge nozzle is contained within the housing; an actuator; first and second drive elements, of which the first is acted upon by the actuator and in turn acts upon the second, and the second acts upon the syringe to discharge its contents through the discharge nozzle, the first drive element being capable of movement relative to the second when the first is acted upon by the actuator and the second is restrained by the syringe; of the actuator and the first drive element, one comprises a flexible arm that engages with a drive surface on the other, allowing the actuator to act upon the first drive element and preventing the former from moving relative to the latter; and the second drive element comprises a stop that prevents the flexible arm disengaging from the drive surface until the first drive element has been advanced to a nominal release position relative to the second, whereupon the flexible arm disengages from the drive surface, allowing the actuator to move relative to the first drive element and thus releasing the syringe from the action of the actuator, whereupon the biasing means restores the syringe to its retracted position. - View Dependent Claims (19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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20. An injection device comprising:
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a housing adapted to receive a syringe having a discharge nozzle, the housing including means for biasing the syringe from an extended position in which the discharge nozzle extends from the housing to a retracted position in which the discharge nozzle is contained within the housing; an actuator; a drive, acted upon by the actuator and acting upon the syringe to discharge its contents through the discharge nozzle; and of the actuator and the drive, one comprises a flexible arm that engages with a drive surface on the other, allowing the actuator to act upon the drive and preventing the former from moving relative to the latter; in which the flexible arm is prevented from disengaging from the drive surface until the drive has been advanced to a nominal release position, whereupon the flexible arm disengages from the drive surface, allowing the actuator to move relative to the drive and thus releasing the syringe from the action of the actuator, whereupon the biasing means restores the syringe to its retracted position.
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Specification