GB573167A - Improvements in or relating to medical syringes - Google Patents

Abstract

573,167. Medical syringes. EVERETT, S. J. Dec. 1, 1943, Nos. 20089/43, 123/44, 10059/44, and 15162/44. [Class 81 (ii)] A medical syringe having a glass barrel is reinforced at the forward end by means of a closely fitting permanent outer cover. As shown in Fig. 1, the syringe includes a barrel 1 formed with an integral glass front closure 2 having a glass nozzle 3. A thin metal cover 4 surrounding the nozzle 3, front closure member 2, and lower end of the barrel 1, is secured in position by a thin cushion 5 of solder. The cover may be made of stainless steel or brass and affixed alternatively by means of powdered ceramic or glass, or by direct welding. The cover may also be made of synthetic resin and fixed by an adhesive. In a modification, the front closure member, made of glass or ceramic, fits into the end of the barrel, and the parts are held together solely by the cover with a solder cushion, or in addition joined at their cylindrical surfaces of contact by welding or by means of a fit. In another modification the cover comprises a metal band, which is soldered about the forward end of the barrel, the latter being fixed by compression between the tightly fitting closure member and the metal band. In a further modification, the metal ring may be slightly tapered internally and shrunk directly on the correspondingly tapered end of the barrel. In all cases, materials of similar thermal expansion are selected to minimise strains set up during manufacture and sterilisation at high temperatures. Specification 557,363 is referred to.