초록 ▼

A liquid dispensing pump includes a one-piece piston capable of not only effecting a pumping operation but also an outlet valve opening and closing function upon limited relative axial movement. In one embodiment, the piston reciprocates and forms a valve seat for a container vent opening extending

A liquid dispensing pump includes a one-piece piston capable of not only effecting a pumping operation but also an outlet valve opening and closing function upon limited relative axial movement. In one embodiment, the piston reciprocates and forms a valve seat for a container vent opening extending through a closure cap provided on the pump body, and in another embodiment, the pump cylinder reciprocates and forms a valve seat for opening and closing the container vent opening. The pump chamber defined by the cylinder has a valved inlet which may be formed by a sleeve depending from the piston and an upstanding conduit in the cylinder or may be formed by a ball check valve in the cylinder.

대표청구항 ▼

A liquid dispensing pump, comprising a pump cylinder defining a pump chamber having a valved inlet opening, a reciprocable piston having an annular piston skirt at one end thereof in sliding engagement with the wall of said chamber between upstroke and downstroke positions of said piston, a discharg

A liquid dispensing pump, comprising a pump cylinder defining a pump chamber having a valved inlet opening, a reciprocable piston having an annular piston skirt at one end thereof in sliding engagement with the wall of said chamber between upstroke and downstroke positions of said piston, a discharge head for effecting downstroke movement of said piston, said discharge head having a discharge orifice, and a discharge passage extending through said piston and said head providing communication between said pump chamber and said orifice, said head being in sliding engagement with an opposite end of said piston for limited relative inward and outward shifting movement of said head for opening and closing said discharge passage, said piston having a valve member at said opposite end in engagement with the wall of said discharge passage in said head during the closing of said discharge passage, and said valve member comprising a valve skirt forming an annular opening with an enlarged section in said wall during the opening of said discharge passage, whereby inward depression of said discharge head effects an opening of said passage and moves said piston into said downstroke position, liquid thereby being dispensed from said chamber through said passage and orifice.