GB577206A - Hypodermic syringe - Google Patents

Abstract

577,206. Hypodermic syringes. LOCKHART, M. L. Sept. 7, 1943, No. 14638. [Class 81 (ii)] In a hypodermic syringe comprising a medicament receptacle 10, Fig. 3, closed by a piston 12, the needle 34 is enclosed in a container 16 to one end of which the medicament receptacle is telescopically fitted and sealed in the position shown, and the other end is closed at 48, the closure being punctured by the needle on relative movement of the two telescoping parts. The tubes 10 and 16 may be made of glass or transparent plastic material and the closure may consist of a thin layer of the plastic material or a rubber cap. The piston, which may be grooved as shown in Fig. 6, is made of rubber or similar material impregnated with wax or other lubricant and is provided with a socket 26 to receive the inner pointed end of the needle 34. A stop tube 40 limits the downward movement of the needle so that on further telescopic movement the piston 12 is punctured, and finally the medicament ejected through the needle. The open end of the medicament tube may be slotted at 24 and formd with a bead 22 to engage in a groove 30 in the needle tube, the joint being sealed by wax. Alternatively the joint may be effected by means shown in Figs. 6 and 7, in which projections 21 slide through grooves 27 and are held between shoulders 25 and projections 23, until released by relative rotation of the telescoping parts. To prevent backward movement of the needle a leaf spring element 29, Figs. 6 and 9, may be attached to the needle between two washers and is formed so as to wedge against the needle tube and to co-act with a ridge 35. When a solid and a liquid are to be kept separate until just before injection, the upper end of the tube 10 may be closed by a hollow plug 52, Fig. 5, made for example of rubber, and containing the solid sealed from the liquid by a stopper 60. On pressure at 58 the stopper 60 is pushed out by a rod 56.