Foam dispenser having selectively pressurized cartridge

• US 20100270328A1
• Filed: 04/23/2010
• Published: 10/28/2010
• Est. Priority Date: 10/23/2008
• Status: Active Grant

• Current Assignee: GOJO Industries Incorporated
• Original Assignee: GOJO Industries Incorporated
• Inventors: Quinlan, Robert L.
• Granted Patent: US 8,215,521 B2
• Time in Patent Office: Days
• US Class Current: 222/1
• CPC Class Codes: A47K 5/16 with mechanical drive food mixers A47J43/04
• CPC Class Codes: B05B 12/008 integrated in or attached to a discharge apparatus, e.g. a spray gun
• CPC Class Codes: B05B 12/02 for controlling time, or sequence, of delivery
• CPC Class Codes: B05B 12/087 Flow or presssure regulators, i.e. non-electric unitary devices comprising a sensing element, e.g. a piston or a membrane, and a controlling element, e.g. a valve
• CPC Class Codes: B05B 7/0025 with a compressed gas supply

Abstract

A foam dispenser and method of operation of the foam dispenser provides that a cartridge of liquid having an air head is retained in the dispenser and maintained under pressure by an air compressor when at rest, i.e., when the foam dispenser in not being actuated. Air and liquid conduits communicate respectively between the air head and liquid maintained in the cartridge and a foam generating head. Valves selectively close flow through the conduits. In this way, when the foam dispenser is actuated the valves can simply be opened for the appropriate amount of time to advance air and liquid to the foam generating head and dispense foam at a dispensing location.

Claims

1. A method for dispensing foam from a foam dispenser including a dispenser housing;

a cartridge removable and replaceable within the dispenser housing, the cartridge containing a foamable liquid section and an air section;

an air compressor communicating with the air section;

a foam generating head;

an outlet air conduit extending between the air section and the foam generating head;

an air dispensing valve associated with the outlet air conduit to regulate the flow of air therethrough;

an outlet liquid conduit extending between the liquid section and the foam generating head; and

an liquid dispensing valve associated with the outlet liquid conduit to regulate the flow of liquid therethrough, the method comprising the steps of;

maintaining the pressure within the cartridge within a desired dispensing pressure range while the foam dispenser is unactuated, the pressure being generated by the air compressor and establishing a pressure head in the air section of the cartridge to separately force both air and liquid respectively toward the air dispensing valve and the liquid dispensing valve;

maintaining the air dispensing valve and the liquid dispensing valve in a closed position while the foam dispenser is unactuated to prevent flow of air and liquid through their respective outlet air conduits and outlet liquid conduits to the foam generating head; and

upon receiving an actuation request of the foam dispenser, opening the air dispensing valve and the liquid dispensing valve so that air and liquid flow to and through the foam generating head under the pressure established in said step of maintaining the pressure within the cartridge within a desired dispensing pressure range.

2. The method of claim 1, wherein the foam dispenser further includes a vent in communication with the air section in the cartridge, and said step of maintaining the pressure within the cartridge within a desired dispensing pressure range includes:

monitoring the pressure, P, within the cartridge,

comparing the pressure P with the desired dispensing pressure range, P_D, and

if P is greater than P_D, venting the cartridge through the vent, and

if P is less than P_D, adding pressure to the cartridge through the air compressor.

3. The method of claim 2, further comprising the steps of:

when said pressure P is within the desired dispensing pressure range P_D, monitoring an actuation means of the foam dispenser to determine if the foam dispenser has been actuated.

4. The method of claim 3, wherein the actuation means of the foam dispenser includes a hand sensor sensing the presence of a hand at a dispensing location of the foam dispenser, and said step of monitoring an actuation means includes monitoring the hand sensor to determine if a hand is present at the dispensing location.

5. The method of claim 2, wherein P_D is from 2 to 10 psi.

6. The method of claim 1, wherein, in said step of opening the air dispensing valve and the liquid dispensing valve, said valves are open for a time span of from 0.1 to 1.0 seconds.

7. The method of claim 1, wherein, in said step of opening the air dispensing valve and the liquid dispensing valve, said liquid dispensing valve is opened before said air dispensing valve.

8. The method of claim 1, wherein, in said step of opening the air dispensing valve and the liquid dispensing valve, said liquid dispensing valve is opened for a shorter amount of time than said air dispensing valve.

9. The method of claim 1, wherein the air compressor generates a max pressure, Pmax, and said step of maintaining the pressure within the cartridge within a desired dispensing pressure range includes:

monitoring the pressure, P, within the cartridge,

comparing the pressure P with the desired dispensing pressure range, P_D, and

if P is less than P_D, adding pressure to the cartridge through the air compressor, wherein Pmax is within the desired pressure range P_D.