Patent ID: 8157114

Claim:
A container having a hollow interior defined by a wall and at least one closed end, including: a plunger mounted within the interior of the container for reciprocal movement toward and away from the closed end, the plunger having a threaded opening, and an outer peripheral edge adjacent an inner side of the wall, wherein a surface of the outer peripheral edge of the plunger is concave and facilitates an elastic deformation of the outer peripheral edge against the inner side of the wall; a threaded shank mounted within the interior of the container and cooperates with the threaded opening of said plunger, wherein said plunger frictionally engages the inner side of the wall to militate against the free rotation of said plunger about said shank; a manually operated member attached to the threaded shank to affect rotary motion of the shank relative to the plunger whereby rotary motion of the member causes linear movement of the plunger within the interior of the container; and a support formed on the inner side of the wall, wherein said plunger and said support cooperate to militate against movement of said plunger toward the closed end.