Abstract: An auto-disable syringe is disclosed which prevents re-use of the syringe whetver dose is delivered on the first use. A restrictor bobbin comprises two elements: a plunger lock 1 and a barrel lock 20 which are relatively freely movable for a limited distance. The barrel lock includes a barb 27 which engages with the barrel interior wall to prevent proximal movement of the barrel lock, whilst the plunger lock includes a barb 6 which engages with the plunger to prevent distal movement of the plunger withy respect to the barrel lock. The plunger lock includes a further barb 9 which is engageable with the plunger to prevent proximal movement of the plunger. A lock release 40 inlcudes a latch tine 53 which, in the syringe as shipped, prevents engagement of the barb 9 with the plunger. After withdrawal of fluid, e.g. a liquid medicament, initial distal movement of the plunger causes the latch 53 to disengage with the barb 9, thereby preventing any further proximal movement of the plunger.

Abstract: An auto-disable syringe is disclosed which prevents re-use of the syringe whetver dose is delivered on the first use. A restrictor bobbin comprises two elements: a plunger lock 1 and a barrel lock 20 which are relatively freely movable for a limited distance. The barrel lock includes a barb 27 which engages with the barrel interior wall to prevent proximal movement of the barrel lock, whilst the plunger lock includes a barb 6 which engages with the plunger to prevent distal movement of the plunger withy respect to the barrel lock. The plunger lock includes a further barb 9 which is engageable with the plunger to prevent proximal movement of the plunger. A lock release 40 inlcudes a latch tine 53 which, in the syringe as shipped, prevents engagement of the barb 9 with the plunger. After withdrawal of fluid, e.g. a liquid medicament, initial distal movement of the plunger causes the latch 53 to disengage with the barb 9, thereby preventing any further proximal movement of the plunger.