Improvements in ampoule hypodermic syringes

140,755. Spahlinger, H. March 27, 1919, [Convention date]. Pumps, syringes, and like appliances.-An ampoule syringe, in which the fluid to be injected is separated from the needle and is held in a transparent container, comprises a glass tube a with a piston plug b having a capillary passage c in communication with the needle c. A hood f of transparent or opaque material protects the needle and may be integral with the part b or held by a joint cover l. A stiletto g traverses the needle e and passage c, and serves to perforate a diaphragm h when it is desired to use the fluid d which is injected by removing the joint cover m and pushing the tube a in the direction of the needle. Fluid tightness and easy movement are facilitated by a joint k consisting of a mixture of paraffin and oil placed between the piston b and the tube a. The diaphragm h may be replaced by a plug of a material insoluble in the fluid. In modifications, the plug b may be hollow and closed at the junction with the needle by an insoluble plug. In another construction, the hollow plug may be formed with an inturned tube, and the liquid is then contained in the annulus thus formed. In these modifications, the needle is protected by a closely-fitting removable sheath.