Foam-at-a-distance systems and anti-drip mechanisms for such systems

Patent metadata

Field	Value
Publication number	US-11304572-B2
Application number	US-202016939225-A
Country	US
Kind code	B2
Filing date	Jul 27, 2020
Priority date	Apr 25, 2018
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

Exemplary foam-at-a-distance systems include a spout, a container, and a foam generator having a suck-back mechanism located within the spout. The system includes a liquid pump chamber, an air pump chamber, a liquid conduit and an air conduit. The foam generator has a differential bore housing. The differential bore housing has a first portion with a first inside bore and a second portion with a second inside bore, wherein the first inside bore has a smaller diameter than the second inside bore. A piston having a seal extending from the piston that is in contact with the second inside bore is also included. A mixing chamber is located in the large bore. Movement of the seal in an upstream direction provides negative pressure in the second mixing chamber and draws in fluid from the outlet.

First claim

We claim:

1. A foam-at-a-distance system comprising:
a dispenser housing;
an outlet nozzle;
a container retainable by the dispenser housing;
a foam generator having a suck-back mechanism located proximate the outlet nozzle;
a liquid pump;
an air pump;
a liquid conduit extending upward from the liquid pump to a liquid inlet in the foam generator;
an air conduit extending upward from the air pump to an air inlet in the foam generator;
the foam generator having a housing;
the housing having a first portion with a first inside bore and a second portion with a second inside bore, wherein the first inside bore has a smaller diameter than the second inside bore;
a piston having a first seal in contact with the first inside bore;
a second seal extending from the piston and in contact with the second inside bore;
wherein the second seal prevents air from flowing between the second seal and the second inside bore;
wherein the piston includes a hollow stem;
a first mixing chamber located downstream of the first seal and upstream of the second seal;
the liquid inlet located upstream of the first seal;
an air inlet located downstream of the first seal and upstream of the second seal;
an aperture in the hollow stem placing the first mixing chamber in fluid communication with the interior of the hollow stem;
a second mixing chamber located in the second inside bore;
one or more mix media located downstream of the second mixing chamber; and
an outlet;
wherein movement of the second seal in an upstream direction provides negative pressure in the second mixing chamber and draws in fluid from the outlet.

2. The foam-at-a-distance system of claim 1 wherein the liquid pump and the air pump are portions of a single pump.

3. The foam-at-a-distance system of claim 1 further comprising a seat member located proximate the liquid inlet and the piston comprises a sealing member for sealing against the seat member.

4. The foam-at-a-distance system of claim 1 wherein the second seal is located on a suck-back sleeve.

5. The foam-at-a-distance system of claim 1 wherein the air inlet in the foam generating housing is located in a wall of the large bore.

6. The foam-at-a-distance system of claim 1 wherein the mix media and the outlet lie along an outlet axis and the piston lies along a piston axis and wherein the outlet axis is offset from the piston axis.

7. The foam-at-a-distance system of claim 6 wherein the outlet axis and piston axis form an angle of between about 0 degrees and 90 degrees.

8. A foam-at-a-distance system comprising:
a spout located at an upper position and configured to dispense fluid on a user's hand;
a foam generator having a suck-back mechanism located proximate an end of the spout;
a liquid pump portion;
a container located below the spout in fluid communication with the liquid pump portion;
an air pump portion in fluid communication with ambient air;
a liquid conduit extending upward from the liquid pump portion to a liquid inlet in the foam generator;
an air conduit extending form the air pump portion upward to an air inlet in the foam generator;
the foam generator having a housing;
the housing having a first portion with a first inside bore and a second portion with a second inside bore, wherein the first inside bore has a smaller diameter than the second inside bore;
a piston having a first seal in contact with the first inside bore;
a second seal extending from the piston and in contact with the second inside bore;
wherein the second seal prevents air from flowing between the second seal and the second inside bore;
a first mixing chamber located downstream of the first seal and upstream of the second seal;
the liquid inlet located upstream of the first seal;
the air inlet located downstream of the first seal and upstream of the second seal;
a second mixing chamber located in the second inside bore;
wherein movement of the second seal in an upstream direction provides negative pressure in the second mixing chamber and draws in fluid from the outlet.

9. The foam-at-a-distance system of claim 8 further comprising a seat member located proximate the liquid inlet and the piston comprises a sealing member for sealing against the seat member.

10. The foam-at-a-distance system of claim 8 further comprising a biasing member to bias the piston in the upstream direction.

11. The foam-at-a-distance system of claim 8 wherein the second seal is located on a suck-back sleeve.

12. The foam-at-a-distance system of claim 11 further comprising serrations on the suck-back sleeve.

13. The foam-at-a-distance system of claim 8 wherein a mix media and an outlet lie along an outlet axis and the piston lies along a piston axis and wherein the outlet axis is offset from the piston axis.

14. The foam-at-a-distance system of claim 13 wherein the outlet axis and piston axis form an angle of between about 0 degrees and 90 degrees.

15. A foam dispensing system comprising:
a spout configured for dispensing fluid onto a user's hand;
a container located below the spout;
a foam generator located within the spout;
a liquid pump chamber;
an air pump chamber;
a liquid conduit extending upward to a liquid inlet in the foam generator;
an air conduit extending upward to an air inlet in the foam generator;
a piston;
the piston moving between a first position and a second position;
wherein liquid flowing in through the liquid inlet moves the piston in a first direction;
wherein a biasing member moves the piston in a second direction that is substantially opposite the first direction;
a first piston seal, wherein the first piston seal allows liquid to flow past the first piston seal;
wherein the liquid inlet is located upstream of the first piston seal;
wherein the air inlet is located downstream of the first piston seal;
a second piston seal located downstream of the air inlet;
wherein the second piston seal forms a seal between an inside bore and the piston and wherein air is prevented by the second piston seal from flowing between the second piston seal;
a mixing chamber;
wherein movement of the second piston seal in a downstream direction decreases the mixing chamber volume and movement of the second piston seal in an upstream direction increases the volume of the mixing chamber and draws in fluid from the outlet.

16. The foam dispensing system of claim 15 further comprising a seat member located proximate the liquid inlet and a piston having a liquid inlet wiper seal and a sealing member for sealing against the seat member.

17. The foam dispensing system of claim 15 wherein the first piston seal reciprocates in a first diameter bore and the second sealing member reciprocates in a second diameter bore and wherein the second diameter is greater than the first diameter.

18. The foam dispensing system of claim 15 wherein the second piston seal is located on a suck-back sleeve.

19. The foam dispensing system of claim 18 further comprising serrations on the suck-back sleeve.

20. The foam dispensing system of claim 15 wherein a mix media and an outlet lie along an outlet axis and the piston lies along a piston axis and wherein the outlet axis is offset from the piston axis.

Assignees

• Gojo Ind Inc

Inventors

• Ciavarella Nick E
• Jenkins Dennis K

Classifications

• B05B11/1097

  with means for sucking back the liquid or other fluent material in the nozzle after a dispensing stroke · CPC title

• B05B11/1087

  Combination of liquid and air pumps · CPC title

• B05B11/1052

  Actuation means (locking means therefor B05B11/1059; the dispensing stroke being affected by the stored energy of a spring B05B11/109) · CPC title

• A47K2005/1218

  Table mounted; Dispensers integrated with the mixing tap · CPC title

• B05B12/122

  responsive to presence or shape of target (B05B12/124 takes precedence) · CPC title