Check valve for use with a syringe

Claim 1

A valve for use in sealing a fluid supply while permitting selective withdrawal of the fluid, comprising: a tubular side wall defining a first end, a supply end, a tube interior and a tube exterior; a diaphragm connected to said side wall and extending across said tube interior to close said interior, said diaphragm being located along said tube interior remote from said supply end and said first end; said diaphragm defining a slit therein extending diametrically across said diaphragm; said diaphragm defining a concave surface thereon toward said first end; housing means for securing said side wall and disposed in sealing contact with said side wall for sealing said supply end from said tube exterior, said housing means surrounding and enclosing said supply end and defining a port extending through said housing means and communicating with said supply end, said housing means terminating in contact with said side wall remote from said first end to expose said first end; a flange defined about said side wall at said supply end, said housing means defining a groove therein for containing said flange, whereby said side wall is secured into said housing means; said housing means including: an inlet portion closing said supply end of said tubular side wall and disposed against said flange, said port extending through said inlet portion to open into said tube interior; and a retaining portion connected to said inlet portion and having a central opening for passage of said tubular side wall therethrough; said inlet portion and said retaining portion being connected together to define said groove for containing said flange.