Injection device

Abstract

Abstract 664,044. Hypodermic syringes. BECTON DICKINSON & CO. Feb. 9, 1949 [March 2, 1948], No. 3591/49. Class 81 (ii) A device for hypodermically injecting medicament without the aid of a skin-piercing needle has a medicament receiving chamber, the medicament in which is expelled by means imparted with potential energy by rotation of a further member, the said potential energy being released during expulsion of medicament. A compression spring 14 is housed at the rear end of the device between a cup 13 disposed within the casing 5 and a cap 16 which on being screwed into position compresses the spring 14. The cup 13 is maintained in position by the engagement of racks 26 mounted on the cup 13 with gear wheels 25 mounted on a shaft 23 which passes transversely through slots 28 in the cup and the casing and is controlled by a button 24 outside the casing. A shaft 20 secured to the inner face of the cap 16 is provided with a worm 21 at its free end which engages with a worm wheel also mounted on the shaft 23. As the cap 16 is rotated the worm wheel turns and the cup 13 is accordingly moved to compress the spring 14. When an injection is to be made the compressed spring 14 is released by pushing the button 24 on the shaft 23 inwards against a spring 27 with the consequent disengagement of the gear wheels 25 with the racks 26. The compression spring 14, on release pushes the cup 13 forwardly. A plunger 12 attached to the base of the cup 13 moves through a cylinder 11 at the forward end of which it engages a stopper 10 of an ampoule 8. The stopper is pushed within the ampoule 8 with the consequent ejection of medicament through the stopper piercing cannula 7 in the cap 6 at the front of the device.

Inventors

No inventors recorded.

Bibliographic Details