| 摘要 |
1,041,920. Hypodermic syringes. S. J. SARNOFF. Oct. 19, 1964 [Oct. 18, 1963], No. 42484/64. Heading A5R. A hypodermic syringe comprises an injector gun having a plunger 28 which is projected in a barrel 26 by a spring 46 on releasing a detent 38, a cartridge holder 10, and a quick-action coupling means 22 connecting the holder and the gun by simple relative axial movement. The plunger 28 is slidable within the barrel 26 to the forward end of which a cartridge holder 10, comprising a head 14 and rearwardly directed fingers 18, is secured by a sleeve 22 which compresses the fingers about the barrel. At the rear end, the barrel has a threaded plug 34 having a pair of rearwardly directed stepped fingers 70 which co-operate with an abutment 42 projecting inwardly from the rear of an outer sleeve 30 which is slidable on the barrel. The plunger is slidable within the plug 34 and the abutment 42 and carries a spring detent 38. A compression spring 46 which bears against the plug and a collar 44 on the plunger is compressed on retracting the plunger, which is locked in retracted position by engagement between the detent and the plug. The plunger is released for ejecting medicament from the cartridge 52 by pressing the outer sleeve against a spring 40 forwardly relative to the barrel so that the abutment causes disengagement of the detent with the plug. The spring 46 projects the plunger and the piston 50 of the cartridge. The barrel is rotatable relative to the outer sleeve between a position in which a stepped portion 76 of each of the plug fingers engages the abutment, to prevent relative sliding movement of the barrel and the outer sleeve, and a position in which the plug fingers are aligned with recesses 74 on each side of the abutment, to permit relative sliding movement of the barrel and the outer sleeve for releasing the plunger. The relative angular positions of the barrel and outer sleeve are determined by the selective engagement of blocks 80 with pairs of opposed flat surfaces 88, 90 on the barrel having arcuate shoulders 92, 94. The speed at which the plunger is projected is adjusted by rotation of a ring 104 having an aperture of varying width which occludes an opening 102 in the forward portion of the barrel to a variable extent. |
