Manually operated liquid dispensing pump

Claim 1

A manually operated pump for the delivery of viscous liquid stored within a container upon which said pump is mounted, said pump comprising: a ring nut mounted on a mouth of said container, said ring nut including a first annular shoulder and an annular seal extending into said container; a pump body comprising a hollow cylinder having an axis and a ring at one end, said ring resting upon said first shoulder of said ring nut for supporting said pump body in the axial direction, said ring having a pressure equalization opening, said hollow cylinder having a second end extending into said container and including an annular internal valve seat and a product drawing tube coaxial with said cylinder and communicating with said cylinder via said valve seat; a ball valve in said second end and engageable with said valve seat; a closure ring mounted on said ring nut and having a center circular opening coaxial with said pump body; a hollow delivery stem extending through said central opening of said closure ring, said hollow stem having a lower end positioned inside said pump body, said lower end of said stem including a first annular projection having a first annular downwardly extending lip, said lower end of said stem and said first lip together defining walls of a first annular concave seat; a shaped body in said pump body, said shaped body having a cylindrical mid-portion and an upper end extending into said hollow stem, said upper end of said shaped body including a delivery passage whereby said liquid may be introduced into said hollow stem at said lower end thereof, said shaped body having a lower end including an annular guide portion having an outer diameter substantially equal to an inner diameter of said hollow cylinder of said pump body, whereby said hollow stem and shaped body are guided in the axial direction, said mid-portion of said shaped body including a second annular projection having a second annular upwardly extending lip, said cylindrical mid-portion and said second lip together defining walls of a second annular concave seat spaced from said first seat by a first distance; conical spring means extending between said ball valve and said lower end of said shaped body for biasing said ball valve into engagement with said valve seat and for biasing said shaped body and said hollow stem in a direction away from said valve seat; and a soft elastic seal positioned in said pump body between said first and second annular concave seats, said seal comprising: (a) an inner cylindrical portion closely surrounding said mid-portion of said shaped body in a slidable manner, the axial height of said inner portion being less than said first distance, whereby said seal is axially movable between a first position in which an upper end of said inner portion is inserted into said first concave seat so as to open said delivery passage of said shaped body, and a second position in which a lower end of said inner portion is inserted into said second concave seat so as to seal said delivery passage of said shaped body, (b) an outer cylindrical portion adjacent the inner cylindrical walls of said hollow cylinder of said pump body, said outer portion having axial ends bent into engagement with said inner cylindrical walls of said hollow cylinder of said pump body so as to form annular seals therewith, and (c) an annular connecting portion connecting said inner and outer cylindrical portions.