Drain closure assembly

Claim 1

A drain closure assembly comprising: a socket member adapted to extend at least partially within the drain to be closed and defining a through opening for permitting a liquid to flow into said drain, said socket member including a sealing surface; a stopper member of a flexible material and having a substantially dome-shaped configuration substantially entirely across the entire surface thereof, an edge of said stopper member engaging the sealing surface of said socket member in a sealing relationship to inhibit a flow of liquid into said drain when said stopper member is in a closed position; means, including a support member secured to said stopper member and slideable relative to said socket member, for supporting said stopper member in cooperation with said socket member in a position extending over said opening and in engagement with said socket member to seal said opening; said stopper member being structurally adapted to flex to an inverted position out of engagement with said sealing surface of said socket member in response to an external force acting on said stopper member to release said seal and to flex from said inverted position back to said substantially dome-shaped configuration in response to an additional external force acting therein without accompanying axial movement of said support means; means for urging said stopper member in a direction away from said socket member when said external force is released; and means for limiting the movement of said support member when said stopper means is urged from said socket member.