GB2171615A - Foam producing - Google Patents

Abstract

A foam producing dispenser has a nozzle cap (11) with a foaming collar (37) extending outwardly of a wall containing a discharge orifice (22) for producing a foam as foamable product issues from the discharge orifice in a conical spray pattern and impinges against the inner surface of the foaming collar (37) so that foam is produced soley by a turbulence to which the discharged product is subjected. <IMAGE>

Description

SPECIFICATION Foam production method and dispenser This invention relates generally to a method and a manually operated pump for dispensing a foamable product as a foam, and more particularly to such a pump having a nozzle cap for generating foam through turbulance.

Foam dispensers having a foam generating device at the nozzle end are generally disclosed in U.S. Patents 4,219,159 and 4,350,298. In the former, the foam device includes foaming screens as well as an aspirating chamber having aspirating passages for aspirating air to be mixed with the foamable product in the chamber so as to produce a foam upon discharge through the screens. In the latter, air inlet ports are provided for aspirating air, and further provision is made for the product colliding with arms lying in the path of the dispensed product to effect foaming. These arms constitute an obstacle wall with which the spray iiquid from the orifice collides, and a plurality of outlet ports are defined by adjacent arms.

These foam dispensers are, however, rather complex in structure requiring a multiplicity of parts which add substantially to the time and expense of production and assembly. It is therefore desirable to produce a foam dispenser without the need for aspirating passages or foam generating screens, homogenizing elements (as in U.S. 3,709,437) or other means through which the foamable product must pass for producing a foam.

An atomizerforthe spraying of liquid fuel is disclosed in U.S. Patent 1,192,901 in the form of a tip member having a tip chamber of different shapes with a discharge orifice at the base thereof. During the spray, oil issuing from the discharge orifice under high pressure creates a partial vacuum in the tip chamber which creates an atomization of the product as it mixes with air below atmospheric pressure within the chamber. Also, the creation of a partial vacuum within the tip chamber causes an inflow of air over the edge of the tip, which air penetrates a hollow oil cone for effecting a solid cone of atomized oil therein.The side wall of the tip chamber extends to such a distance beyond the transverse plane containing the discharge orifice that the open end or mouth of the chamber is of such a diameter that the outside of the extending cone of oil will not strike the wall. Thus, although this tip member has no air aspirating passages for atomization, the outer edge of the wall of the tip chamber is so positioned that the wall of the cone of atomized oil clears such outer edge so as to form an annular pocket for air between the walls of the tip chamber and the cone of atomized oil.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to produce a manually operated dispensing pump and method for discharging a foam with the use of a foam generating element of simple construction having no air aspirating passages, screens or other obstacles required for generating a foam.

Another object of this invention is to provide such a foam dispenser as having a foaming nozzle cap with a wall containing a discharge orifice, the cap having a foaming collar extending outwardly of such wall, with the collar surrounding the discharge orifice at a given radial distance and having an inner surface terminating a predetermined distance from such wall so that the product issuing through the orifice is subjected to turbulence as the product impinges against such irinersurface of the collar and is thereby emitted as a foam from such inner surface.

A further object of the invention is to provide such a foam dispenser wherein the inner surface of the collar diverges outwardly, is slightly conical or is cylindrical.

Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view of a manually operated dispenser incorporating the foaming nozzle cap according to the invention shown in cross-section; Figure 2 is a sectional view taken substantially along the line 2-2 of Fig. 1; Figure 3 is a cross-sectional view of another embodiment of the foaming nozzle cap of the invention; and Figures 4 and 5 are partial sectional views of still further embodiments of the foaming nozzle cap of the invention.

DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, a trigger operated dispenser, generally designated 10 in Figure 1, has a foaming nozzle cap 11 externally mounted thereto for effecting the dispensing of a foamable product as a foam. It is to be pointed out that dispenser 10 of Figure 1 is for illustrative purposes only since foaming nozzle cap 11 may be provided with other types of trigger operated sprayers such as that of U.S. Patent 4,174,069, or may be employed with vertical action finger pumps of any known type for generating a foam, without departing from the invention.

Basically, dispenser 10 has a pump body 12 which includes a collar 13 to facilitate mounting the dispenser on the neck of a container (not shown) of foamable product to be dispensed. A drip tube 14 extends from the pump body into the container so as to form a product inlet passage controlled by an inlet check valve such as a ball check 15. During the suction stroke of the pump, as assisted by a return spring 16, product enters pump chamber 17 and, upon operation of trigger 18 during the compression stroke, piston 19 compresses the product within chamber 17 which product is discharged under pressure through a valve controlled discharge passage 21 and out through a discharge orifice 22.As in any such manually operated pump, the discharge orifice forms the terminal end of the discharge passage which is valve controlled in some manner either at the pump chamber as in 4,174,069, or adjacent the discharge orifice itself.

Nozzle cap 11 has a skirt 23 with an internal annular groove 24 to facilitate mounting the nozzle cap in place on the pump body as this groove receives an annular flange (not shown) on the pump body when the cap is snap fitted in place. A transverse wall 25 of the nozzle cap contains discharge orifice 22 centrally located therein, and a sleeve 26, lying coaxial with the nozzle cap, surrounds wall 25. This sleeve is supported by an outer wall 27 of the nozzle cap which may be conically shaped as shown. An inwardly directed, annular seal ring 28 on wall 27 may be provided for sealing against a cooperating sleeve (not shown) of the pump body to avoid leakage of product from the nozzle cap.

Sleeve 26 includes a collar 29 extending inwardly of wall 25 and surrounding a part 31 on the pump body which has a pair of arcuate flanges 32,33 so as to define a swirl chamber 30 therebetween adjacent wall 25. Tangential slots 34 and 35 (Fig. 2) are formed between these flanges so that, when fluid is forced into the swirl chamber through these slots, via an axial groove 36 in collar 29, the product is caused to rapidly whiri adjacent discharge orifice 22 so as to produce a vortex or fluid whirling action upon issuing from.the discharge orifice in an outwardly and substantially conical spray pattern.

Sleeve 26 further comprises a foaming collar 37 extending outwardly from wall 25. Inner surface 38 of this collar 37 is spaced a predetermined radial distance from the discharge orifice, and extends outwardly from wall 25 a predetermined distance such that the swirling conical spray issuing from the discharge orifice will impact against this surface 38 which thereby creates a turbulence effect resulting in a foaming of the product as in the manner illustrated in Figure 1. Thus, as the foamable product issues from the discharge orifice, it is directed against surface 38 of the foaming collar causing a fluid flow in which the velocity thereof varies erratically in magnitude and direction such that by this turbulent flow the product issues as a foam from the foaming coilar.No air aspiration passages, screens or homogenizing elements or other obstacles through which the foamable product is forced, are required for the nozzle cap according to the invention.

Surface 38 of the foaming collar may be outwardly flared as shown in Figures 1 and 3, may be cylindrical as at 38a in Figure 4, or slightly conical as at 38b in Figure 5, without departing from the invention.

Nozzle cap 11A of Figure 3 is similar to the aforedescribed nozzle cap except that the swirl chamber at the upstream side of waIl 25 is formed by a pair of arcuate flanges (only one such flange 39 is shown) mounted on the inner surface of wall 25, similarly as disclosed in U.S. Patent 4,174,069. Thus, tangential slots are formed between these flanges which may cooperate with a needle valve (not shown) on the pump body, so that when the foamable product is forced into the swirl chamber through these slots, it is caused to rapidly whirl adjacent discharge orifice 22. Moreover, collar 29 is slightly bulged at its free end as at 41 and may be relatively flexible compared to that of the more rigid remainder of the cap. This bulged end 41 bears against the inner wall of a nipple (not shown) extending from the pump body.

Otherwise, the foamable product is caused to foam after it issues from the discharge orifice in a swirling spray as it impacts against surface 38 of the foaming collar to thereby create a turbulence effect resulting in a foaming of the product, as similarly described with reference to Figure 1.

For the foregoing it can be seen that a foam generating nozzle cap has been devised for dispensing a foamable product as a foam without the need for any air aspirating passages, screens, homogenizing elements or other obstacles through which the product must pass in order to effect a foam as in the prior art. An outwardly extending foaming collar effects the foam discharge according to the invention as a turbulent effect is produced upon the conical mist spray particles impacting againstthewall ofthefoaming collar.

Obviously, many modifications and variations of the present invention are made possible in view of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Claims (9)

1. A manually operated pump for dispensing a foamable product as a foam, comprising, a pump housing having valve controlled inlet and discharge passages defining a discharge path for the foamable product from a supply container through a discharge orifice, the pump being capable of discharging an outwardly diverging spray of the foamable product th rough said discharge orifice, a foaming nozzle cap externally mounted on said pump housing and having a wall containing said discharge orifice, said cap being devoid of any air aspiration passage means, and said cap having a foaming collar extending outwardly of said wall, said collar surrounding said discharge orifice at a predetermined radial distance therefrom and having an inner surface terminating a predetermined distance from said wall such that the product emitted through said orifice is subjected to turbulence as the product impinges against said inner surface of said collar and is thereby emitted as a foam from said surface solely by turbulent effect.

2. The pump according to claim 1, wherein said inner surface of said collar diverges outwardly.

3. The pump according to claim 2, wherein said inner surface of said collar is conical.

4. The pump according to claim 1,wherein said inner surface of said collar is cylindrical.

5. A nozzle cap for effecting a foam discharge of a foamable product from a manually operated dispenser, comprising a cap body adapted to be mounted at the discharge end of the dispenser, said body being devoid of any air aspiration passage means, and said body having a wall containing a discharge orifice, a foaming collar extending outwardly of said wall, said collar surrounding said discharge orifice at a predetermined radial distance therefrom and having an inner surface terminating a predetermined distance from said wall such that foamable product emitted through the discharge orifice is subjected to turbulence as the product impinges against said inner surface of said collar and is thereby emitted as a foam from said surface solely by turbulent effect.

6. The nozzle cap according to claim 5, wherein said inner surface of said collar diverges outwardly.

7. The nozzle cap according to claim 6, wherein said inner surface of said collar is conical.

8. The nozzle cap according to claim 5, wherein said inner surface of said collar is cylindrical.

9. A method of effecting foam discharge of a foamable product through a nozzle cap from a manually operated dispenser, comprising the steps of discharging a spray of the foamable product through a discharge orifice of the nozzle cap, subjecting the spray to turbulence upon leaving said orifice by impinging the spray against a wall of the nozzle cap surrounding the discharge office downstream, thereof to thus produce a foam solely by turbulent effect.