Foam device

• US 4,219,159 A
• Filed: 01/05/1979
• Issued: 08/26/1980
• Est. Priority Date: 01/05/1979
• Status: Expired due to Term

• Current Assignee: AFA Products, Inc. (Indesco International, Inc.)
• Original Assignee: The AFA Corporation
• Inventors: Wesner, Walter H.
• Primary Examiner(s): Reeves, Robert B.
• Assistant Examiner(s): Church, Gene A.
• Application Number:
  US06/001,046
• Time in Patent Office: 599 Days
• Field of Search: 239/333, 239/343, 239/370, 239/428.5, 239/432, 169/14, 169/15
• US Class Current: 239/343
• CPC Class Codes: B05B 11/0005 Components or details of single units wherein the flow is effected by a pump B05B11/1042
• CPC Class Codes: B05B 7/0062 including sieves, porous members or the like

Abstract

A very compact foam-generating element for use in conjunction with a trigger-actuated dispenser is characterized by its insensitivity to its manner of attachment to and adjustment on the dispenser and features a combination of foam forming means located upstream of an expansion chamber having a nozzle at its inlet and terminated downstream by screening means, the screening means, expansion chamber and nozzle cooperating to produce a tightly packed, fine textured foam of even consistency by extending the time of treatment of the semi prepared foam received from the foam forming means, the screening means meanwhile adding air and further breaking up the liquid. The foam forming means provides non-contact jetting of the liquid through an aspirating chamber into a foam forming chamber having a diameter or cross section that is substantially the same as that of the aspirating chamber. The diameter or cross section of the expansion chamber preferably is substantially larger than that of the foam forming chamber. In one embodiment the foam-generating element is adapted to fit over the nozzle of a trigger-type dispenser; in another embodiment the element replaces the nozzle altogether; and in further embodiments the element is incorporated within the molded structure of trigger-actuated piston type and bellows type dispensers to form integral foam dispensers.

Claims

1. A foam-generating element which comprises a body adapted at one end to receive liquid pumped from a trigger-type dispenser and at the other end to dispense foamed product, including

(a) a first chamber within the body for mixing said liquid with air,

(b) one or more air passages for introducing air into said first air chamber,

(c) a second chamber adjacent said first chamber, through which the aerated liquid passes, the second chamber being of substantially the same diameter as said first chamber and being provided with means for mixing the foam,

(d) a third chamber adjacent to and of larger diameter than said second chamber and which receives aerated product from said second chamber,

(e) screening means covering the downstream end of said third chamber, through which the product of the third chamber is forced, and

(f) outlet means for dispensing the foamed product.

2. A foam-generating element which comprises a body means adapted at one end to receive liquid pumped from a liquid dispenser and at the other end to dispense foamed product, including

(a) a first chamber within the body means wherein said liquid is mixed with air,

(b) a second chamber adjacent said first chamber through which said aerated liquid passes, the second chamber being of substantially the same cross section as said first chamber,

(c) a third chamber adjacent to and of larger cross section than the second chamber and which receives aerated product from said second chamber,

(d) screening means covering the downstream end of said third chamber and through which the product in the third chamber is forced, and

(e) outlet means for dispensing the foamed product.

3. A foam-generating element which comprises a body means adapted at one end to receive liquid pumped from a liquid dispenser and at the other end to dispense foamed product, including

(a) a first chamber within the body means wherein said liquid is mixed with air,

(b) a second chamber adjacent said first chamber through which said aerated liquid passes, the second chamber being of substantially the same or lesser cross section than said first chamber,

(c) a third chamber adjacent to and of larger cross section than the second chamber and which receives aerated product from said second chamber,

(d) said first, second and third chambers having a common axis, said first chamber including in a wall adjacent said one end of said body means an orifice from which said liquid is pumped in the form of a spray by said dispenser, the axis of said spray of liquid being substantially coincident with said common axis, the cross sections of said first and second chambers transverse of said axis being substantially the same, and transverse of said axis said third chamber having a larger cross section than said second chamber,

(e) screening means covering the downstream end of said third chamber and through which the product in the third chamber is forced, and

(f) outlet means for dispensing the foam product.

4. The foam-generating element of claim 3 in which said first chamber is provided with a plurality of slots in other walls thereof, said slots being wedge-shaped and extending in a direction transverse to said common axis, the narrow edge of said slots being in the inner wall of said first chamber whereby to effect an increase in the velocity and turbulence of the air drawn through said slots into said chamber by the movement of said spray of liquid and facilitation of the mixing of said liquid and air to cause preliminary foaming in said first chamber.

5. A foam-generating element comprising a body means adapted at one end to receive liquid pumped from a trigger-actuated liquid dispenser and at the other end to dispense foamed product, said foam-generating element including within said body means

(a) foam-generating means for mixing air with said liquid to produce foam,

(b) foam enhancing means including an expansion chamber and a nozzle at the inlet to said expansion chamber to receive foam generated by said foam-generating means, said expansion chamber having a downstream opening,

(c) screening means covering the downstream opening of said expansion chamber, and

(d) an outlet conduit for dispensing the foamed product.

6. A foam-generating element as specified in claim 5 wherein said screening means tends to function as an obstacle to induce an upstream flow of a peripheral portion at least of the foam in said expansion chamber, and wherein said expansion chamber includes means for entraining said upstream directed foamed portion with the central downstream flow of foam therein whereby the period of time of foaming action in the expansion chamber for said foamed portion is extended and the quality of the foamed product is improved.

7. A foam-generating element as specified in claim 6 wherein the cross section of said outlet conduit is at least as large as the cross section of the downstream opening of said expansion chamber.

8. A foam-generating element as specified in claim 6 wherein said foam-generating means includes a foam forming chamber, wherein the transverse cross section of said expansion chamber is substantially larger than the transverse cross section of said foam forming chamber, and wherein said expansion chamber includes an upstream extending peripheral portion that encircles said foam forming chamber.

9. A foam-generating element as specified in claim 8 wherein said foam-generating means further includes an aspirating chamber into which air is introduced for mixing with said liquid.

10. A foam-generating element as specified in claim 9 wherein said aspirating chamber includes one or more wedge-shaped sharp-edged radial slots in its walls through which air is introduced for mixing with said liquid.

11. A foam-generating element as specified in claim 10 wherein said foam forming chamber includes interrupter rings formed in the wall thereof for agitating and homogenizing the mixture of liquid and air entering therein from said aspirating chamber.

12. A foam-generating element as specified in claim 9 wherein said aspirating chamber includes an orifice in a wall thereof adjacent said one end of said body means, said orifice having an axis and adapted to form along said axis in said aspirating chamber a spray of liquid, wherein said foam forming chamber has an axis generally coincident with the axis of said orifice, the cross sections of said aspirating chamber and said foam forming chamber transverse to said axis being substantially the same, whereby said spray of liquid passes into said foam forming chamber substantially unimpeded by the interface of said aspirating and foam forming chambers.

13. A foam dispenser comprising

a body member in or to which the other components of the dispenser are retained or secured,

a pump means in said body member for pumping and pressurizing liquid,

inlet and outlet means in said body member for the delivery of liquid to and the discharge of liquid from said pump means, said outlet means including an outlet bore to which liquid pressurized by said pump means is delivered,

trigger means secured to the body member for actuating said pump means, and

a foam-generating element located substantially wholly within said outlet bore, said element comprising a body means adapted at one end to receive liquid pumped by said pump means and at the other end to dispense foamed product.

14. A foam dispenser as specified in claim 13 wherein said body means of said foam-generating element includes foam forming means for mixing air with liquid pumped by said pump means and received at said one end of said foam-generating element to produce foam, an expansion chamber having an upstream opening for receiving foam-generated by said foam-generating means, and having a downstream opening, screening means covering the downstream opening of said expansion chamber, and an outlet conduit for dispensing the foamed product out of the other end of said body means, said outlet conduit receiving foam forced through said screening means from said expansion chamber when said pump means is actuated by said trigger means.

15. A foam dispenser as specified in claim 14 wherein said screening means of said foam-generating element tends to function as an obstacle to induce an upstream flow of a peripheral portion at least of the foam in said expansion chamber, and wherein said expansion chamber includes means for entraining said upstream directed foamed portion with the central downstream flow of foam therein whereby the period of time of foaming action in the expansion chamber for said foamed portion is extended and the quality of the foamed product is improved.

16. A foam dispenser as specified in claim 15 wherein said foam forming means of said foam-generating element includes a foam forming chamber, wherein the transverse cross section of said expansion chamber is substantially larger than the transverse cross section of said foam forming chamber, and wherein said means for entraining said upstream directed foamed portion includes a nozzle formed at the inlet to said expansion chamber.

17. A foam dispenser as specified in claim 16 wherein said foam forming means of said foam-generating element includes an aspirating chamber into which air is introduced for mixing with said liquid.

18. A foam dispenser as specified in claim 17 wherein said aspirating chamber of said foam forming means is formed with one or more wedge-shaped sharp-edged radial slots in its walls through which air is introduced for mixing with said liquid.

19. A foam dispenser as specified in claim 18 wherein said foam forming chamber of said foam-generating means includes interrupter rings formed in the wall thereof for agitating and homogenizing the mixture of liquid and air entering therein from said aspirating chamber.

20. A foam dispenser as specified in claim 13 wherein said pump means includes a variable volume pump chamber, and said inlet and outlet means each include an actuatable control valve means.

21. A foam dispenser as specified in claim 20 wherein said variable volume chamber of said pump means is constituted by a piston and cylinder.

22. A foam dispenser as specified in claim 21 wherein said control valve means in said inlet means comprises a check valve and said control valve means in said outlet means comprises a combination spinner and check valve.

23. A foam dispenser as specified in claim 20 wherein said variable volume chamber of said pump means is constituted by a hollow resilient pump member that is adapted to be compressed and comprises a bellows member having a sealed end, flexible corrugated walls, and an open end in engagement with said body member.

24. A foam dispenser as specified in claim 23 wherein said control valve means of said inlet and outlet means are included within an internal cavity in said body member, said cavity being open on its upper end and closed by a cover plate having means cooperating with said body member to separate said inlet means from said outlet means and including a pliable valve element captured between said cover plate and said body member, said valve element having an inlet portion and an outlet portion each of which portions seals against an individually associated portion of the surface of said cavity to close said inlet means and said outlet means, respectively.

25. A foam dispenser as specified in claim 23 wherein said foam-generating element includes

(a) a first chamber within said body means wherein said liquid pumped by said pump means is mixed with air,

(b) a second chamber adjacent said first chamber through which said aerated liquid passes, said second chamber being of substantially the same diameter as said first chamber,

(c) a third chamber adjcent to and of larger diameter than said second chamber and which receives aerated product from said second chamber,

(d) screening means covering the downstream end of said third chamber and through which the product in the third chamber is forced, and

(e) outlet means for dispensing the foamed product.

26. A foam dispenser as specified in claim 25 wherein said first chamber of said foam-generating element is provided with one or more wedge-shaped slots for introducing air into said chamber, wherein said first and second chambers are cylindrical in form and said first chamber has a diameter that is at least as great as that of said second chamber, and wherein said second chamber is provided with means for agitating or mixing the aerated product of said first chamber.

27. A foam dispenser as specified in claim 26 wherein said body member of said foam dispenser is provided with a slot for introducing air into said first chamber.

28. A foam dispenser as specified in claim 13 including spinner means positioned in said outlet bore between said pump means and said one end of said foam generating element.

29. A foam dispenser as specified in claim 24 including spinner means positioned in said outlet bore between the outlet portion of said valve element and said one end of said foam-generating element, said spinner means being fixed in position.

30. A foam dispenser as specified in claim 29 wherein said spinner means are molded integrally with said body member.