Valved cannula assembly

Claim 1

In a valved cannula assembly for use with inserted instruments, the valved cannula assembly including a cannula sleeve, a valve housing having an internal open area, a flapper valve assembly having a plugging member adapted to be moved by said inserted instruments, a seating gasket and an axial bore for insertion and removal of said instruments, where the seating gasket in combination with the plugging member of the flapper valve assembly or an inserted instrument creates a seal in the axial bore, the improvement comprising the combination of: an annular seating gasket having a relatively thin cross-section and a central opening sized slightly smaller than said axial bore; a gasket receiving member positioned within said valve housing, said gasket receiving member having a relatively planar distal end with a central aperture positioned thereon, said gasket receiving member having said flapper valve assembly mounted on said distal end within said internal open area of said valve housing, whereby said plugging member extends through said central aperture to contact said central opening of said seating gasket; an annular gasket retaining collar having a recess adapted to receive said seating gasket and retain said seating gasket in fixed position against said distal end of said gasket receiving member whereby said distal end is between said seating gasket and said flapper valve assembly; and a plugging member abutting said gasket retaining collar and connected to said gasket receiving member whereby said gasket retaining collar is retained in a fixed position against said distal end of said gasket receiving member.