Injection devices
First Claim
1. An injection device comprising an elongate body in which is housed a charged capsule with a needle at the forward end of the capsule and a plunger projecting from the rear end of the capsule, coil spring means arranged between the rear end of the body and a drive member that receives the rear end of the plunger and which spring means, when released from compression, act through the drive member on the plunger to push the plunger forwards and thereby carry out an injection, and a release mechanism for the drive member including a sleeve over part of the body and slidable longitudinally thereof between rearward and forward positions, and a trigger carried by said body and accessible through an aperture in said sleeve, the sleeve being initially in said rearward position where it holds the trigger inoperable and in retaining engagement with the drive member but which when shifted to said forward position allows the trigger to be actuated and thus the drive member to be released.
1 Assignment
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Accused Products
Abstract
An injection device holds a syringe in the form of a capsule having a needle projecting from its forward end and a plunger extending from its rear end. The rear end of the plunger received in the drive member, which, when released, is urged forward by a coil spring, thus projecting the needle and expressing the dose. The drive member is held captive in its rearward primed position by a detent provided by the body of the device. A sleeve covering a substantial part of the body can shift longitudinally of it from an initial rearward position to a forward position in which it either disengages the drive member from the detent, or in which a trigger is freed from actuation to release the drive member.
364 Citations
5 Claims
- 1. An injection device comprising an elongate body in which is housed a charged capsule with a needle at the forward end of the capsule and a plunger projecting from the rear end of the capsule, coil spring means arranged between the rear end of the body and a drive member that receives the rear end of the plunger and which spring means, when released from compression, act through the drive member on the plunger to push the plunger forwards and thereby carry out an injection, and a release mechanism for the drive member including a sleeve over part of the body and slidable longitudinally thereof between rearward and forward positions, and a trigger carried by said body and accessible through an aperture in said sleeve, the sleeve being initially in said rearward position where it holds the trigger inoperable and in retaining engagement with the drive member but which when shifted to said forward position allows the trigger to be actuated and thus the drive member to be released.
Specification