Manually operated pump for the delivery under pressure of liquid substances

Claim 1

A manually operable pump for the delivery under pressure in micronized form of a liquid stored within a container on which the pump is mounted, comprising: an elongated hollow body having a metering chamber formed therein, said metering chamber being bounded in part by an inner wall of said hollow body; a tube for carrying said liquid to be dispensed into said metering chamber; a one-way valve operably disposed between said tube and said metering chamber; an elongated stem coaxially disposed in said hollow body and axially movable with respect thereto, an upper end of said stem projecting outside said hollow body and supporting a nebulizing cap, said stem having an axial passage therein, a channel extending between said axial passage and an outer surface of said stem communicating said metering chamber and said axial passage, and a stop rib disposed below said channel; spring means reacting between said hollow body and said stem for biasing said stem away from the bottom of said metering chamber; a resilient annular seal member slidingly disposed on said outer surface of said stem within said hollow body, said metering chamber being bounded in part by said seal member, said seal member and said stem being relatively axially displaceable between a first position wherein said seal member abuts said stop rib and blocks said channel and a second position wherein said seal member does not block said channel, said seal member comprising a radially outer lip resiliently sealingly engaging said inner wall of said hollow body in said first and second positions and an inner lip resiliently sealingly engaging said outer surface of said stem in said first and second positions, said outer surface of said stem comprising frusto-conic surface means coaxial with said stem for radially displacing said inner lip of said seal member when said seal member is moved from said first position toward said second position; and means for biasing said seal member toward said first position comprising said frusto-conic surface means and said inner lip of said seal member.