Patent ID: 11904143
Assignee: AMGEN INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 13:
14. An actuating mechanism for an injector, the injector comprising a housing having a syringe assembly at least partially disposed within the housing and adapted to being coupled to the actuating mechanism, the actuating mechanism comprising:
a frame member adapted to be disposed within the housing, the frame member having a threaded opening formed between a first surface and a second surface;
a plunger assembly comprising a threaded plunger rod and a plunger face, the threaded plunger rod threadably coupled to the threaded opening of the frame member, the plunger face being disposed near the syringe assembly;
a plunger rod guide coupled to the plunger assembly to maintain alignment between at least the frame member and the plunger assembly;
a torque spring configured to exert a torque and cause relative rotation between at least one of (a) the plunger assembly and the frame member or (b) the plunger rod guide and the frame member; and
a damper mechanism that dampens an effect of the torque spring, the damper mechanism formed by at least one of the frame member, the plunger assembly, and the plunger rod guide;
wherein upon the torque spring exerting a torque, the damper mechanism exerts an opposing force to reduce an impact force between the plunger assembly and the syringe assembly.