Foaming soap dispensers and methods

Abstract

A soap dispenser can be configured to dispense an amount of foam soap. In some embodiments, the dispenser can include a venturi device with an air inlet and a soap inlet. In certain implementations, the dispenser can include a flexible impeller pump. In some such embodiments, the pump can be configured to draw liquid soap through the soap inlet of the venturi device and air through the air inlet of the venturi device. The soap and air can mix to form foam, which can be drawn into the pump and dispensed via a nozzle in communication with the pump. In some embodiments, the dispenser includes a screen, which can modify the texture of the foam.

1 . A soap dispenser comprising:
 a housing;   a reservoir configured to store liquid soap;   an aspirator comprising a first inlet, a second inlet, and an outlet, the first inlet in fluid communication with the reservoir, the second inlet in fluid communication with the ambient environment, the outlet in fluid communication with the first and second inlets via a channel;   a pump disposed in the housing and comprising a body and an impeller, the impeller disposed in an inner cavity of the body, the inner cavity in fluid communication with the aspirator outlet, the pump configured to encourage a flow of liquid soap from the reservoir through the first inlet and to encourage a flow of air from the ambient environment through the second inlet, the channel of the aspirator configured to encourage mixing of the flows of liquid soap and air to generate soap foam; and   a discharge nozzle configured to discharge a portion of the soap foam, the discharge nozzle in fluid communication with the inner cavity of the pump body.   
     
     
         2 . The soap dispenser of  claim 1 , further comprising a valve disposed along a flow path between the reservoir and the aspirator. 
     
     
         3 . The soap dispenser of  claim 1 , wherein the aspirator further comprises a first tapered portion in fluid communication with the channel and a second tapered portion in fluid communication with the channel. 
     
     
         4 . The soap dispenser of  claim 1 , wherein the first inlet and the outlet are generally axially aligned. 
     
     
         5 . The soap dispenser of  claim 1 , wherein a first inlet diameter is larger than a second inlet diameter. 
     
     
         6 . The soap dispenser of  claim 1 , wherein a first inlet diameter is larger than a channel diameter. 
     
     
         7 . The soap dispenser of  claim 1 , wherein the second inlet is generally centered on an axis that is substantially perpendicular to the longitudinal axis of the channel. 
     
     
         8 . The soap dispenser of  claim 1 , wherein the impeller comprises a central body portion and a plurality of flexible arms. 
     
     
         9 . The soap dispenser of  claim 8 , wherein each of the flexible arms comprises a rounded protrusion. 
     
     
         10 . The soap dispenser of  claim 8 , wherein the inner cavity is configured to bend at least one of the flexible arms more than another one of the flexible arms. 
     
     
         11 . The soap dispenser of  claim 1 , wherein the inner cavity comprises a generally eccentric-circular shape. 
     
     
         12 . The soap dispenser of  claim 1 , wherein the impeller comprises a bore. 
     
     
         13 . The soap dispenser of  claim 12 , further comprising an actuation mechanism connected to the impeller bore. 
     
     
         14 . The soap dispenser of  claim 1 , wherein the pump is configured to generate a negative pressure that is less than a pressure at the aspirator outlet. 
     
     
         15 . The soap dispenser of  claim 1 , wherein the pump further comprises an inlet pocket near a pump inlet and an outlet pocket near a pump outlet, the inlet pocket being larger than the outlet pocket. 
     
     
         16 . The soap dispenser of  claim 1 , wherein the pump further comprises a pocket configured to transition between a first configuration and a second configuration, the pocket being larger in the first configuration than in the second configuration. 
     
     
         17 . The soap dispenser of  claim 1 , further comprising a flow-enhancing member in fluid communication with the inner cavity of the pump body, the flow-enhancing member disposed downstream from the pump. 
     
     
         18 . The soap dispenser of  claim 17 , wherein the flow-enhancing member is a screen. 
     
     
         19 . The soap dispenser of  claim 17 , wherein the flow-enhancing member is configured to provide a back pressure. 
     
     
         20 . The soap dispenser of  claim 1 , wherein the discharge nozzle is a duckbill valve. 
     
     
         21 . The soap dispenser of  claim 1 , further comprising a holding chamber disposed downstream of the aspirator, the holding chamber configured to store the soap foam for a period of time. 
     
     
         22 . A method of dispensing foaming liquid soap from a soap dispenser, the method comprising:
 drawing a flow of liquid soap from a reservoir and through a first inlet of an aspirator;   drawing a flow of ambient air through a second inlet of the aspirator;   generating soap foam in a channel of the aspirator;   drawing the soap foam from an aspirator outlet and through an inlet of a pump, the pump comprising a body and an impeller, the impeller disposed in an inner cavity of the body; and   discharging a portion of the soap foam from a nozzle.   
     
     
         23 . The method of  claim 22 , further comprising drawing the soap foam into a holding chamber, the holding chamber disposed downstream from the aspirator. 
     
     
         24 . The method of  claim 23 , further comprising storing the soap foam in the holding chamber for a period of time. 
     
     
         25 . The method of  claim 22 , wherein drawing the flow of liquid soap from the reservoir and through the first inlet comprises drawing the flow of liquid soap through a valve. 
     
     
         26 . The method of  claim 22 , further comprising generating a negative pressure within the aspirator channel relative to ambient. 
     
     
         27 . The method of  claim 22 , further comprising generating a region of pressure near the second inlet that is less than a region of pressure near the first inlet. 
     
     
         28 . The method of  claim 22 , further comprising driving the impeller, the impeller including a central body portion and a plurality of flexible arms. 
     
     
         29 . The method of  claim 28 , wherein driving the impeller comprises moving a pocket between a first configuration and a second configuration, the pocket being larger in the first configuration than in the second configuration. 
     
     
         30 . The method of  claim 28 , wherein driving the impeller comprises moving each of the flexible arms between a first configuration and a second configuration, wherein each of the flexible arms is more bent in the first configuration than in the second configuration. 
     
     
         31 . The method of  claim 22 , further comprising generating a negative pressure within the inner cavity relative to ambient. 
     
     
         32 . The method of  claim 21 , further comprising generating a pressure within the inner cavity that is less than the pressure at the aspirator outlet. 
     
     
         33 . The method of  claim 22 , further comprising discharging the soap foam from an outlet of the pump and through a flow-enhancing member. 
     
     
         34 . The method of  claim 33 , wherein discharging the soap foam through the flow-enhancing member further comprises generating a back pressure.