Abstract: An injection device including a syringe having a needle, a barrel and a plunger. The device is configured to provide an automatic injection cycle and includes a drive coupling arrangement between a driving spring and the syringe. In operation, a drive force can be selectively transmitted between the respective first and second parts of the drive coupling arrangement depending upon their relative rotational positions such that, when the first and second parts are in a first relative rotational position during the dispensing stage, a driving force is transmitted to the plunger to drive the plunger into the barrel, and, when the first and second parts are in a second relative rotational position during the retraction stage, no force is transmitted to the plunger to allow the plunger and the syringe to retract.

Abstract: An injection device including a syringe having a needle, a barrel and a plunger. The device is configured to provide an automatic injection cycle and includes a drive coupling arrangement between a driving spring and the syringe. In operation, a drive force can be selectively transmitted between the respective first and second parts of the drive coupling arrangement depending upon their relative rotational positions such that, when the first and second parts are in a first relative rotational position during the dispensing stage, a driving force is transmitted to the plunger to drive the plunger into the barrel, and, when the first and second parts are in a second relative rotational position during the retraction stage, no force is transmitted to the plunger to allow the plunger and the syringe to retract.