INJECTOR Russian patent published in 2003 - IPC

FIELD: medical equipment; applicable for injection of prescribed doses of drugs. SUBSTANCE: injector has body, piston rod with noncircular cross-section and male thread, piston rod drive containing piston rod guide conjugated with piston rod cross-section, and nut which is made for impossible axial motion and conjugated with thread of piston rod for formation of self- locking threaded joint. Means for dose volume setting has nonself-locking threaded joint along which button is located for execution of injections by rotating member for dose volume setting with its protrusion out of body. With axial return of button for performance of injection, this axial motion transforms into rotation of one of members of piston drive relative to the other. Single-directed joint between nut member and piston rod guide allows rotation in one direction which provides for piston rod motion to distal direction. Joint has initial resistance which is to be overcome before rotation and being sufficiently large for counteraction of torques during dose volume setting. EFFECT: higher accuracy in dose volume setting due to convenient cancellation of improperly set dose volume. 8 cl, 17 dwg