Apparatus for dosing and forming soap foam

An apparatus for forming lather or soap foam for washing and/or shaving purposes comprises an actuation lever which simultaneously serves to drive a piston, a liquid soap-dosing pump and a membrane pump for generating compressed air. A perforated wall of a conduit or line enables blowing the compressed air into a dosed quantity of liquid soap located within a mixing chamber, to thereby form a coarse bubble lather or soap foam which subsequently is blown through a porous body, homogenized and compacted. Different embodiments of the apparatus can be realized and it is particularly suitable for use as a foot actuated structure and for producing hot lather for shaving. A preferred construction contains an intermittently operated heater for preheating the compressed air, to thereby accomplish a particularly effective generation of hot lather. The apparatus has the advantage of increased economy owing to its reduced consumption of liquid soap and can be faultlessly hygienically operated and is especially environmentally protective.

BACKGROUND OF THE INVENTION 
The present invention relates to a new and improved construction of 
apparatus for producing soap foam or lather. 
Generally speaking, the lather producing apparatus of the present 
development is of the type comprising a liquid soap-dosing device which 
can be activated by a lever and further contains therein a source of 
pressurized gas or air, which opens by means of closable orifices or 
openings and/or lines or conduits into a mixing chamber. The lather 
producing apparatus is equipped with at least one supply container or 
reservoir for an aqueous soap solution or liquid soap. Moreover, the 
lather producing apparatus can contain a heater device for producing warm 
lather or soap foam. 
As is well known, soap dispensers of the most different designs are 
employed in public and private washrooms, toilets and the like. Among 
these there are known lather producing soap dispensers employing a 
propellant gas composed of dichlorodifluoromethane (more commonly known 
under the trademark "FREON 12") and the widespread use thereof has been 
restricted because of environmental reasons. 
A lather producing apparatus according to the general type herein above 
described, is known to the art from U.S. Pat. No. 3,712,512, granted Jan. 
23, 1973, wherein, with the aid of an exchangeable pressurized gas flask 
(not air) there is produced, by means of liquid soap a coarse bubble foam 
or lather, within a mixing chamber or compartment which is controlled by a 
float valve. By activating a lever for a random length of time and which 
is mounted at an end thereof and connected with a valve, the lather or 
soap foam flows, in a corresponding quantity, initially through a 
perforated plate arranged forwardly of the valve. This perforated plate 
reduces the size of the bubbles and increases the lather or foam density. 
Thereafter, the soap foam or lather flows through an outlet nozzle. This 
outlet nozzle has arranged forwardly thereof an electrical heating device 
enabling heating-up of the outflowing lather. 
This prior art lather producing apparatus requires a large amount of space, 
and furthermore, the pressurized gas container or flask, must be regularly 
exchanged. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind it is a primary object of the present 
invention to provide a new and improved construction of apparatus for 
dosing and producing lather or soap foam which is not associated with the 
aforementioned drawbacks and limitations of the prior art proposals 
discussed above. 
Another and more specific object of the present invention aims at providing 
a new and improved construction of lather producing apparatus which is 
environmentally protective, has only modest spatial requirements, can be 
employed in a number of different ways and does not require any exchange 
of an exchangeable pressurized or compressed gas source. 
Now in order to implement these and still further objects of the invention, 
which will become more readily apparent as the description proceeds, the 
invention contemplates that the actuation lever is simultaneously provided 
for the drive of a piston arranged in a cylinder compartment or chamber of 
the liquid soap-dosing or dispensing pump and for the compression and 
infeed of the pressurized gas or the pressurized air. 
When the lather producing apparatus of the invention is provided with a 
heater or heating device, then it can be beneficially employed for 
producing warm or hot lather and particularly can be employed during 
shaving. 
According to a further feature of the invention, the piston is constructed 
as a slide for closing and opening of the infeed means for the liquid soap 
to the cylinder compartment and for closing and opening a connection 
opening between the cylinder compartment and the mixing chamber. With this 
design it is possible to limit in portions the maximum dosed quantity. 
There is beneficially possible a reproducible quantity of produced foam, 
following each lever actuation, and independently of the actuation speed 
of the lever. 
The compressed air source can be designed as a membrane pump. With this 
construction there is realized a particularly simple and maintenance-free 
or low maintenance compressed air source. 
It is also possible for the lather producing apparatus to be designed such 
that the axis of the membrane pump extends perpendicular to the axis of 
the piston or, as the case may be, to a line parallel to the axis of the 
piston of the liquid soap-dosing pump. This affords an exceedingly space 
saving construction and produces a kinematically favorable movement course 
in the drive mechanism of both pumps. 
When the membrane pump is equipped with a return spring, there is 
beneficially realized the result that the return movement, and thus, the 
pressure formation with the resultant production of lather, is 
accomplished by the return spring, and therefore is constant and 
independent of the activity of the user or operator of the equipment. 
The dimension of the cylinder of the membrane pump and the stroke of the 
membrane piston is dimensioned in relation to a given dosing volume. 
Hence, there is realized the advantage that there prevails a particularly 
favorable volume ratio between the liquid soap and air, amounting to 
approximately 1:15. 
The cylinder compartment is designed to have a dead space or region, 
possessing a blind hole space or chamber for an air cushion. Hence, there 
is provided a gas spring for the liquid soap and the same produces a rapid 
outflow of the liquid soap from the dosing device into the mixing chamber. 
According to a further facet of the invention the inlet opening or line 
opens into the lower portion of the mixing chamber or compartment. In this 
way the inlet opening or line immerses into the dosed liquid soap, 
advantageously thereby producing an intensified formation of bubbles. 
The wall of the inlet opening or line can be perforated, which, in turn, 
affords the benefit that there are produced a large number of smaller 
bubbles. 
It is also possible to arrange a porous body between the mixing chamber and 
the outlet opening for the lather or soap foam. With this construction the 
bubbles are transformed into a homogeneous lather of high density. 
Between the porous body and the outlet opening there can be provided an 
expansion chamber. The lather which flows through the porous body is 
allowed to freely expand, so that even during a subsequent renewed 
compaction to a smaller outflow cross-sectional area, there is realized a 
uniform high lather quality. 
The expansion chamber or compartment can be contained within an 
exchangeable foam deflection body. This affords advantages in terms of 
fabrication and also in terms of equipment maintenance. 
The actuation lever may be designed as a double-arm lever, whereby there is 
realized the benefit of a multifarious use of the equipment and there are 
needed only low actuation forces. The lever arm for the actuation of the 
membrane or diaphragm pump equipped with spring means, is longer than the 
lever arm used for the drive of the piston of the liquid soap-dosing pump. 
This is associated with the advantage that the force applied during 
actuation is predominantly available for the subsequent compression of the 
air in the membrane pump. 
When the actuation lever possesses a hand grip then the lather producing 
apparatus can be advantageously employed in the private sector. The 
actuation lever can be however provided with a foot pedal or the like, 
ensuring for faultless hygienic conditions even when employing the 
equipment in public toilets or other washrooms used by many different 
people. The actuation lever may possess a cable or other traction element 
or equivalent structure connected with the foot pedal. With this design 
there is realized a convenient mounting and handling of the apparatus and 
likewise can be provided for use in washrooms or the like which are 
heavily frequented by individuals. 
The actuation lever can contain a pneumatic or hydraulic or electromagnetic 
tensioning device, which, in turn, affords a still greater operating 
comfort. 
It is also possible for the lather producing apparatus to contain at least 
one thermostatic and/or electro-optical and/or electrical heating body 
which is electromechanically controlled by the actuation lever. With this 
construction the equipment can be outstandingly employed in barber shops 
and other hairstyling establishments and so forth. By preheating the 
liquid soap and/or the infed air it is possible to optimumly heat the 
lather. 
It is possible to guide through the supply container or reservoir an infeed 
line of a hot water tap location. This provides advantages in terms of 
energy saving. A further design, advantageous from the standpoint of 
saving energy, is to construct the infeed line as a heat exchanger. 
Moreover, the lather producing apparatus can be provided with at least one 
electrical throughflow heater. With this construction there is obtained 
the further advantage that the apparatus can be additionally adapted to 
the momentary field of application.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Describing now the drawings, in FIG. 1 reference character G designates the 
housing of a lather or soap foam dispenser according to a first embodiment 
of the invention. Protruding out of the housing G is an actuation lever 1 
containing a handgrip 1'. Arranged above the housing G is a supply 
container or reservoir V, filled with an aqueous soap solution, also 
referred to herein as liquid soap, the lower portion of which extends into 
the housing G and is connected by means of chamber-like further lateral 
supply containers or pockets (one such pocket being shown in FIG. 5) and 
an infeed means 6 with a cylinder chamber or compartment 4 of a liquid 
soap-dosing pump 3. Within the liquid soap-dosing pump 3 there is arranged 
a piston 2 provided with a substantially cylindrical blind hole bore 2a 
and a piston outlet opening 7'. This piston or piston member 2 is designed 
as a slide-out element and is sealed at one end by means of a suitable 
sealing O-ring 52. Inserted through the end portion 2b of the piston 2 is 
a bearing pin 50 or equivalent structure which is frictionally or 
force-lockingly inserted at both of its ends into a drive bracket 1a or 
equivalent structure. The cylinder chamber or compartment 4 is connected 
by means of a connection opening 7 with a mixing chamber or compartment 8. 
Protruding into the lower portion of the mixing chamber or compartment 8 
is an end of a line or conduit 18, through which flows pressurized air D 
by means of a pressurized or compressed air line 5 and can efflux via the 
openings or apertures 19. 
The pressurized or compressed air is produced within a membrane or 
diaphragm pump 9, through appropriate actuation of the operating or 
actuation lever 1 by application of a force F thereat by the user. The 
cylinder 13 of this membrane pump 9 possesses a membrane or diaphragm 14a 
formed of rubber, which is guided by a membrane piston 14. The membrane or 
diaphragm 14a is centred by a threaded membrane holder 59 upon the 
membrane piston 14. A return or restoring spring 12 is placed about a 
piston rod 14b and urges the membrane piston 14 and also the therewith 
connected actuation elements into the illustrated upper position. 
The membrane piston 14 can move through a maximum stroke H, here shown to 
be in the downward direction, and thus sucks in air by means of an air 
inlet or opening 56 and a flap valve 55 into the cylinder 13. The flap 
valve 55 is formed of, for instance, rubber and is fixed at one end, by 
means of a holder 57, at the cover or top of the cylinder 13. 
Now if the operator no longer activates the actuation lever 1, i.e. there 
is no longer effectual the applied force F, then the membrane piston 14 
moves relatively rapidly, under the action of its restoring spring 12, 
into the upper illustrated position. As a result, the flap valve 55 is 
closed and there is produced a quantity of pressurized or compressed air 
D, which acts by means of the compressed air-line or conduit 5, formed of 
connection channels, upon a ball or spherical element 60 which is 
pre-biased by a valve spring 61 and allows the pressurized air D to flow 
by means of the perforated conduit 18 and its holes or apertures 19 into 
the mixing chamber or compartment 8. 
In the illustrated rest position the cylinder chamber or compartment 4 is 
filled with liquid soap, with the exception of a small, defined dead-space 
chamber or area 15, which essentially is defined by a blind hole space or 
chamber 16. If the actuation lever 1 is activated, then the slide-like 
piston 2 moves up to the end of the cylinder chamber or compartment 4, and 
thus, produces an air cushion 17 by means of the air located in the 
deadspace area 15 and the blind hole space or chamber 16. Consequently, 
the liquid soap is now placed under pressure and such, in the terminal 
position of the piston 2, is forced through the piston outlet opening 7', 
the connection opening 7 and the flap valve 54 which is now consequently 
opened into the mixing chamber 8. 
Now the compressed air D flows, in the described manner, into the mixing 
chamber 8 and, at that location, produces a coarse bubble lather or foam. 
This coarse bubble lather or foam is pressed through a porous body member 
20, a so-called frit or sintered body, and flows through a subsequently 
arranged expansion chamber 21 into a foam deflection body 22 and finally 
through an outlet opening A and then is available at that location in the 
form of a fine, walnut-size lather or soap foam for cleaning purposes or 
otherwise. 
In the embodiment under discussion the axes 10 and 11 of the pistons 14 and 
2 are arranged perpendicular with respect to one another. The force 
transmission from the actuation lever 1, which is designed for instance as 
a double-arm lever, is accomplished by means of the bearing pins 50 and 51 
to a drive bracket 1a and to the piston rod 14b, respectively. 
Moreover, from the illustration of FIG. 1 there are provided closure 
elements 62 for closing the assembly bores and a recess 23 which is used 
for assembly purposes. Additionally, the foam deflection body 22 possesses 
a centering nose 22' as well as an O-ring seal 53. The flap valve 54 or 
equivalent structure may be advantageously formed of a synthetic rubber 
and can be centered at its edge by a partially encircling holder ring 58 
or the like. 
All of the components or parts are fabricated of commercially available 
materials. As the porous body or body member 20 there has been found to be 
suitable a frit formed of PTFE (polytetrafluoroethylene). The membrane or 
diaphragm 14a is preferably a so-called rolling membrane, devoid of any 
fabric, formed on the basis of acrylonitrile-butadiene-caoutchouc, for 
instance available from the German firm Carl Freudenberg, located at 
Reichelheim, West Germany. 
Throughout the description of the remaining Figures of the drawings there 
have been conveniently used the same reference characters to denote the 
same or analogous components. 
Now in FIG. 2 there is shown a fragmentary sectional view which discloses 
in detail the actuation mechanism and its individual elements. The 
actuation lever 1, as mentioned, is a double-arm lever and is provided at 
the outside of its angled or flexed portion 1a' with a respective bearing 
pin 50a, whereas there is mounted internally of such actuation lever 1, 
within a recess 1" shown in FIG. 2a, a drive bracket 1a by means of two 
further respective pins 50'. Extending through the drive bracket 1a is a 
bearing pin 50, by means of which it is possible to transmit forces to the 
piston 2. 
As will be apparent from the drawings, an actuation force F results in a 
rotational movement of the actuation lever 1 through a certain arcuate 
extent, and thus, draws the membrane piston 14, not particularly shown in 
FIG. 2, downwardly by means of its piston rod 14b and the bearing pin 51 
which piercingly extends through such piston rod 14b. At the same time, 
through the action of an appreciably lesser force, transmitted by means of 
the pin 50' and the drive bracket 1a and the further bearing pin 50 to the 
piston 2, this piston or piston member 2 is brought into its front 
terminal position. 
In FIG. 2a there will be additionally apparent the actuation surface 1', 
which is structured for manual actuation of the actuation lever 1. 
Continuing, in FIG. 3 there is illustrated an actuation lever 1b which 
leads to a not particularly here illustrated lather dispenser or apparatus 
which is mounted at a wall, and in relation to the showing of FIGS. 1, 2 
and 2a, is longer and narrower and extends through a brickwork M. In the 
brickwork M there is embedded a guide bushing or sleeve 63. This guide 
bushing 63 possesses a slot 63' for the actuation lever 1b and internally 
thereof there is arranged to be slidable a pin 64 which is domed or arched 
at one side. The pin 64 possesses a blind hole bore 65 into which extends 
the end of the actuation lever 1b and through which piercingly extends a 
rotatable pin 66. Now if a force F is applied in the illustrated manner to 
the pin 64, then the actuation lever 1b is operable in the above-described 
manner. The return of the actuation lever 1b and the pin 64 is 
accomplished, also in this case, by the previously described return or 
restoring spring 12. 
This variant embodiment of lather producing apparatus has the advantage 
that it is capable of being actuated at a location remote from the actual 
apparatus or dispenser. It is particularly suitable for a hygienic 
faultless foot actuation. 
With the embodiment of lather producing apparatus as shown in FIG. 4 there 
are integrated therein two heaters or heating devices 29 and 33, which 
will be discussed more fully hereinafter, serving to form hot lather and 
predominantly being employed for shaving purposes. 
More specifically, a heating element or body 29 is arranged in the 
pressurized air-line or conduit 5 and therefore heats-up the 
throughflowing pressurized or compressed air D before it enters the mixing 
chamber or compartment 8. As a second variant there may be provided a 
throughflow heater 33 which heats-up the outflowing lather. 
Preferably, the heating body 29 and the throughflow heater 33 can be 
operated with a heating potential or voltage UH in the order of twelve to 
twenty-four volts which is not dangerous to the user. In order to turn on 
such voltage UH at the proper point in time there is provided a suitable 
switch, here shown as a microswitch 34. In FIG. 4 the microswitch 34 is 
shown in its switched-off position and its operation is determined by the 
upper end of the actuation lever 1. 
The connection terminals conveniently designated by the positive (+) and 
the negative (-) signs, of course, also can be operated with an 
alternating current voltage and powered by means of thermostatic or 
electronic switches and time-delay elements. Instead of using 
electromechanical switching elements it would also be possible to employ 
electro-optical switching elements, such as conventional light barriers. 
Moreover, the heating means can be turned-on and/or turned-off by relays 
by activating a room lighting system or room ventilation system. 
The heating body or heater 29 has been found to be particularly 
advantageous for the preheating of the air, since such is present in the 
lather in an amount by volume which is approximately 15-fold greater than 
the liquid soap. 
A further variant embodiment for preheating the liquid soap has been shown 
in FIG. 5. The chamber-like structured supply container or reservoir V at 
both side surfaces of the housing G contains an infeed line or infeed 
means 30, or a bypass leading therefrom, which infeed line 30 leads from a 
hot water source B, for instance a boiler, to a hot water tap location 31, 
a water or mixing tap. In order to improve the transfer of heat to the 
liquid soap there is provided a lamella-like heat-exchanger 32 which is 
mounted upon the infeed means 30. 
Moreover, in FIG. 5 there have been symbolically illustrated different 
types of drive mechanisms for a foot actuation of the actuation lever 1. 
An activation or tensioning device 28, which may be pneumatic, hydraulic, 
electrical or electromechanical in nature, is arranged at an inclination 
such that its maximum force F', in the one terminal position of the lever 
1, where the restoring spring 12 is tensioned, develops a maximum torque 
or rotational moment. 
As a further possibility there has been shown at the lower end region of 
the lever 1 the use of a traction cable 25 equipped with a deflection roll 
26. 
A practical exemplary embodiment used in conjunction with an actuation or 
tensioning device 28, responsive to the application of a force or pressure 
P', has been illustrated in FIG. 5a. Here a hydraulic cylinder 28' having 
a foot actuator or pedal 24 is embedded into a brickwork or structure M 
and produces the pressure P' needed for the actuation of the tensioning 
device 28. 
As an alternative to this arrangement there has been shown in FIG. 5b to a 
roller or roll 27 which is mounted in a brickwork or structure M. The 
roller 27 can be rotated by a further foot pedal or actuator 24' and 
produces, by means of the tension or traction cable 25, the force F" in 
the traction cable 25 which is needed for the actuation of the actuation 
lever 1. 
All of the herein disclosed embodiments have low spatial requirements and 
can be integrated into the housings of conventional soap dispensers or 
combined therewith. The molded parts of the apparatus ar advantageously 
fabricated by injection molding from duroplast (commercially available 
thermosetting plastics). 
In order to reduce the force F which must be applied at the actuation lever 
1, it would be possible to pre-bias or pressurize the compressed air also 
by other pneumatic means, such as through the use of CO.sub.2 -cartridges, 
small rotating compressors and so forth. 
By means of the invention it is possible to provide hygienically faultless 
washing and shaving possibilities and in a most economical manner. 
Additionally, in contrast to the heretofore known lather producing 
equipment, with the inventive constructions the consumption of soap or 
liquid soap is appreciably reduced because of the high proportion of air 
in the produced lather, so that, on the one hand, the waste water is 
polluted to a lesser degree and, on the other hand, there does not escape 
into the atmosphere any propellant gas which destroys ozone. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practised 
within the scope of the following claims. Accordingly,