Pumps with container vents

Abstract

Exemplary embodiments of pumps, refill units and dispensers are disclosed herein. Some embodiments include a container for holding a fluid and a pump housing secured to the container. The pump housing includes an annular collar for securing the pump housing to the container. The pump housing includes an air chamber and a vent valve located at least partially within the air chamber. One or more air passageways are provided in the collar for providing air to the air chamber. A compressible liquid pump chamber is also located in the housing. The exemplary embodiment includes a liquid inlet valve for allowing liquid to flow from the container into the compressible pump chamber; and a liquid outlet valve located downstream of the pump chamber.

We claim: 
     
         1 . A refill unit comprising:
 an inverted container for holding a fluid;   the inverted container having a neck portion located on the bottom of the inverted container;   a pump housing secured to the neck of the inverted container to pump liquid;   the pump housing having an annular collar for securing to the neck of the inverted container;   an air chamber located within the pump housing;   a vent valve located at least partially within the air chamber;   one or more air passageways in the collar for providing air to the air chamber;   a compressible liquid pump chamber located in the housing;   a liquid inlet valve for allowing liquid to flow from the container into the compressible pump chamber; and   a liquid outlet valve located downstream of the pump chamber.   
     
     
         2 . The refill unit of  claim 1  wherein the vent valve is located adjacent the liquid inlet valve. 
     
     
         3 . The refill unit of  claim 1  further comprising a seat member, wherein the seat member comprises an air passage and a liquid passage, and the vent valve is located proximate the air passage and the liquid inlet valve is located proximate the liquid passage. 
     
     
         4 . The refill unit of  claim 3  wherein the neck of the inverted container is in contact with the seat member. 
     
     
         5 . The refill unit of  claim 3  wherein the seat member further comprises a deflector member for deflecting air entering the container away from the liquid passage in the seat member. 
     
     
         6 . The refill unit of  claim 1  further comprising a compressible air chamber and a mixing chamber, wherein the mixing chamber has an air inlet in fluid communication with the compressible air chamber and a liquid inlet downstream of the liquid outlet valve and in fluid communication with the liquid pump chamber. 
     
     
         7 . The refill unit of  claim 1  further comprising a liquid contained in the inverted container. 
     
     
         8 . The refill unit of  claim 1  wherein the air passage is located between a wall of the collar and a wall of the inverted container. 
     
     
         9 . A refill unit comprising:
 a container for holding a fluid;   a pump housing secured to the container;   the pump housing having an annular collar for securing the pump to the container;   a seat member located at least partially within the annular collar;   an air chamber located within the pump housing below the seat member;   one or more air passageways in the collar for providing air to the air chamber;   a vent valve secured to the seat member for controlling the flow of air from the air chamber into the container;   a compressible liquid pump chamber located in the housing;   a liquid inlet valve secured to the seat member for allowing liquid to flow from the container into the compressible pump chamber; and   a liquid outlet valve located downstream of the pump chamber.   
     
     
         10 . The refill unit of  claim 9  wherein the air passage is located between a wall of the collar and a wall of the container. 
     
     
         11 . The refill unit of  claim 9  wherein the container is in contact with the seat member. 
     
     
         12 . The refill unit of  claim 9  wherein the seat member further comprises a deflector member for deflecting air entering the container away from the liquid passage in the seat member. 
     
     
         13 . The refill unit of  claim 9  wherein the seat member is a single unitary piece. 
     
     
         14 . A refill unit for a dispenser comprising:
 a container for holding a liquid;   a housing secured to the container;   the housing having a opening;   a sleeve inserted in the opening;   a piston movable within the sleeve;   the piston including a sealing member;   a first aperture through a wall of the opening;   the first aperture placing an area between the sleeve and the opening in fluid communication with the interior of the container;   a second aperture through a wall of the sleeve, the aperture located so that the second aperture is closed off by the sealing member when the piston is in a first position; and   wherein when the piston is in a second position, the second aperture is in fluid communication with the atmosphere.   
     
     
         15 . The refill unit of  claim 14  further comprising a one-way valve located proximate the first aperture to allow air to enter the container. 
     
     
         16 . The refill unit of  claim 15  further comprising a vent tube in fluid communication with the first aperture and extending up into the container to a position that is above the top of a fluid fill level. 
     
     
         17 . The refill unit of  claim 14  further comprising one or more sealing members that create an air passage between the sleeve and the opening. 
     
     
         18 . The refill unit of  claim 15  further comprising a third aperture, the third aperture located in the housing between a liquid inlet valve and a liquid outlet valve, the third aperture placing a liquid chamber located at least partially within the sleeve in fluid communication with the interior of the container. 
     
     
         19 . The refill unit of  claim 18  wherein the inlet valve and the outlet valve are stacked on top of each another. 
     
     
         20 . The refill unit of  claim 19  further comprising an outlet nozzle, wherein the outlet nozzle is secured in a fourth aperture of the housing and the outlet nozzle includes a projecting member that retains the stacked inlet valve and the outlet valve. 
     
     
         21 . The refill unit of  claim 14  wherein the sleeve is located in a substantially horizontal orientation and the piston reciprocates back and forth in a substantially horizontal direction. 
     
     
         22 . A refill unit comprising:
 a container for holding a liquid;   a pump housing secured to the container;   the pump housing having a substantially cylindrical valve cavity and a substantially cylindrical pump cavity;   a sleeve located at least partially within the pump cavity;   an aperture between the valve cavity and the pump cavity;   a piston movable horizontally within the sleeve; and   an inlet valve and an outlet valve stacked on each another,
 wherein the inlet and outlet valve are offset from the neck of the container.