GB933975A — Operating mechanism for automatic hypodermic syringes

USPTO Abstract

933,975. Hypodermic syringes. ASTRA, APOTEKARNES KEMISKA FABRIKER A. B. Feb. 6, 1691 [Feb. 16, 1960; Aug. 31, 1960], No. 4385/61. Class 81(2). Operating mechanism for a hypodermic syringe comprises resilient tongues 3 longitudinally arranged in the syringe body and engaging a spring-loaded rod 6, one end 8 of the syringe body being movable longitudinally of the syringe on release of a retaining device to engage the tongues so that they release the rod for effecting an injection. A unit for threaded attachment to a hypodermic syringe comprises a cylindrical portion 1 having at its rear four flexible tongues 3. Heels 13 on the tongues engage a flange 5 at the rear of a rod 6 which is loaded by a surrounding spring 7. In use a cap 8 is slid forwardly along the cylindrical portion so that projections 9 in the cap move the tongues outwardly to release the rod. The rod is then projected forwardly by the spring to operate the syringe. A detachable split ring 11 which is located between the edge of the cap in inoperative position and a rib 14 prevents inadvertent operation of the device. Specifications 789,029 and 933,976 are referred to.