Device for evacuating air from a container

Claim 1

In a device, for evacuating air from a container having an opening, of the kind comprising (a) a cover provided with a sealing surface to sealingly engage part of said container which surrounds said opening, said cover having an opening which is closable by means of a valve, and (b) a separable evacuating pump having a cylinder for connection to said cover for evacuating air from said container, the improvement that: (i) said pump has a plunger including a circular part having an annular sealing lip which is frustoconical and diverges in the direction of movement of the plunger to cause suction, said plunger being made from a resilient plastics material and having such wall-thickness that said sealing lip during the suction stroke is resiliently pressed against the internal face of said cylinder, and during a compression stroke may be deformed by air pressure such that air may pass out of the cylinder between said lip and the cylinder wall; (ii) said pump cylinder is made from a resilient plastics material; (iii) said pump cylinder has at a free end thereof in a thin annular lip; (iv) said cover has on an upper face thereof an annular flange surrounding said opening of the cover, said annular flange serving to sealingly cooperate with said thin annular lip of the pump cylinder when said pump is pressed axially against the cover; to provide centering of the pump cylinder in relation to the cover and sealing therewith in two planes substantially perpendicular to each other; (v) wherein said valve has a valve member with a ball-shaped part having a downwardly directed stem to pass with clearance through an opening of a wall of the cover, and two projections projecting from said stem in two opposite directions, said projections being normally located below said wall, the distance between the ends of said projections exceeding the diameter of the hole in the cover so as to prevent unintended removal of said valve, said wall in which said hole is provided having a substantially planar upper surface, said opening being cylindrical and having a comparatively narrow dimension compared to said ball-shaped part such that a major part of said ball-shaped part remains easily accessible above said wall, said valve member being made from a material having such resiliently yielding properties that said ball-shaped part can provide sufficient sealing against said wall surrounding said opening of the cover mainly by linear contact, whereas the projections may be yieldingly deformed for insertion and removal of the valve.