FR2286657A1 - Double effect syringe for animal vaccination - with disc valve in piston and inlet for successive doses - Google Patents

Abstract

Double effect syringe, esp. for vaccination of animals, is connected to a recipient filled with vaccine for the successive vaccination of a relatively large number of animals. It comprises a head to which the needle if fixed, A delivery valve is interposed between the head and the base of the cylinder, it consists of a disc, fitted with a central tail with a protuberance, which is applied elastically to the external face of the piston. When the user exerts traction on the head of the piston rod, the valve prevents any return of the vaccine while a fresh does of vaccine enters the cylinder through the orifice. No penetration of air into the syringe is possible during this operation. To inject a dose of vaccine, the user has only to extert pressure on the piston head in descending this closes the valve disc while the vaccine in the cylinder is ejected through the central orifice. The operation is simple and prevents intrusion of air, avoiding deterioration of the injected vaccine.