US 2510955 A
Description (OCR text may contain errors)
2 Sheets-Sheet 1' Filed May 5, 1948 E. M. BRQWN LATHERMAKING MACHINE 2 Sheets-Sheet 2 P N7 W H C S GATE A7 MOUTH 0F SPOUT CLOSED M/A/UTES GATE AT MOUTH 0F 5/ 01/7 OPEN June 13, 1950 Filed May 5, 1948 Jim/W EU 5 M Brawn 2 a A D/ 0 C R m MME H w w 6W MAM 6 4 W W A T R R Z P M E V P;/ AOL Patented June 13, 1950 UNITED STATES PATENT QFFICE LATHERMAKING MACHINE Application May 3, 1948, Serial No. 24,836
This invention relates to lathermaking machines of the type used by barbers and exemplified by Patent No. 2,052,569 issued to William Jensen, September 1, 1936.
In lathermaking machines of this type liquid soap is fed from a reservoir into a mixing chamber inwhich a motor driven agitator or beater whips the soap into a lather to be discharged from the mixing chamber through a spout.
When the machine is first started and the mixing bowl contains only liquid it is essential that there be a slight back pressure developed within the mixing chamber. In the absence of such back pressure a long time is required to whip the liquid soap into a lather. However, if the back pressure rises too high the lather begins to back up through the air inlet vent leading to the mixing chamber, and the liquid feed duct which connects the mixing chamber with the reservoir. This, of course, is an undesirable condition, not only because it results in loss of soap but also because it clogs up the air ventand liquid supply duct.
The discharge mouth of the spout has always been provided with a pivoted closure or gate. In the past this gate served two functions. t assured sanitation and provided the means for building up the desired back pressure in the mixing chamber. Hence, the manufacturer instructed the barber to leave this gate closed for a short interval after he started the machine. This would build up the necessary back pressure but the success of the operation depended upon opening the gate before the back pressure rose to the point where the lather and soap backed up into the air vent. As a result there were numerous failures of the machine in service.
Also, the manufacturer found that during the final testing of the machines before shipment there was a fifty percent rejection because of failure to produce lather within the desired time and with the desired consistency over the test period.
It is the purpose of this invention to overcome these objections of past lather-making machines and to effect the desired result in a simple manner which will not alter the general mode of operation or manner of use of the machine.
More specifically it is an object of this invention to provide means. incorporated within the discharge spout which will quickly build up the desired back pressure within the mixing chamber and then maintain it at the optimum level, thus allowing the-manufacturer to instruct the barber to open the gate at the mouth of the discharge spout when he starts the machine.
With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.
The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed in accordance with the best mode so far devised for the practical application of the principles thereof, and in which:
Figure 1 is a top view of a lathermaking ma:- chine of the type to which this invention appertains;
Figure 2 is a cross sectional view therethrough on the plane of the line 2-2 in Figure 1;
Figure 3 is a perspective view of the discharge spout removed from the machine and with the baflie plate therein;
Figure 4 is a perspective view of the baflle plate per se, showing the same in its condition prior to assembly with the discharge spout;
Figure 5 is a graph depicting the rise of pres sure in the mixing chamber as manifested in the discharge spout of the lathermaking machines heretofore in use; and
Figure 6 is a graph depicting the pressure conditions as they exist with this invention.
Referring now particularly to the accompanying drawings, the numeral 5 designates generally a lathermaking machine of the type here involved and which is quite similar to the machine shown in the aforementioned Patent No. 2,052,569 to William Jensen.
It includes a mixing chamber 5 into which liquid soap is fed from a reservoir l through a port 8 and an agitator 9 driven an electric motor I!) and operating within the mixing chamber .to whip the liquid soap into a lather. Air is drawn into the mixing chamber through an air vent I which debouches into the mixing chamber at a point near the axis of the agitator so that the operation thereof draws air down into the mixing chamber. The lather thus formed is discharged from the mixing chamber through a passageway l2, the outer end portion of which projects from the side of the machine to provide a conveniently located discharge spout.
A cover or gate is is pivoted to the front end of the spout to close the same. Heretofore this pivoted cover or gate had to be kept closed during the initial period of mixing to assure building up a slight back pressure in the mixing chamber as heretofore described. With the present invention, however, the cover is provided merely for sanitary reasons and is opened as soon a the operator starts the motor.
The necessary back pressure within the mixing chamber is produced by the Venturi-like efiect of an apertured baille plate or wall 14 which extends transversely across the spout at a distance back from its discharge end. This plate or wall is also spaced a slight distance from the bottom of the spout to provide a drainage passage 15 through which any reliquifled soap flows back into the mixing chamber, a weir H3 at the extreme end of the spout and the fact that the bottom of the spout slopes down and back assures such return flow.
The aperture or opening l'l is in the central portion of the baffle plate or wall [4 and is ap proximately one-third the diameter of the discharge spout. With the aperture about one-third the diameter of the discharge spout, the baille provides a V enturi-like constriction which quickly causes the optimum back pressure to be built up and maintained within the mixing chamber. Another desirable attribute ofthe Venturi-like constriction is that it does not reduce the volumetric flow of lather through the discharge spout. Though the exact dimensions or" the spout and size of the aperture in the bafile plate are, of course, dependent upon such factors as the efficacy of the agitator and the consistency'of the soap, for purposes of illustration the following dimensions apply in one application of the invention: for the inside diameter of the discharge spout, one and one-quarter inches (1%") and for the diameter of the aperture l1 one-half inch For a one and one-quarter inch (1%") diameter discharge spout it was found that an aperture of three-eighths inch /8") Was too constricting and raised the pressure too high, while a five-eighths inch aperture did not provide sufficient back pressure.
The advantage of this invention is clearly depicted by a comparison of the graphs shown in Figures and 6. In the graph of Figure 6, pressure as measured on a manometer at opposite sides of the apertured wall at points A and B (in Figure 2), is plotted against time. The test depicted by this graph employed the one-half inch aperture above referred to and the gate [3 was open. The curve C represents the pressure at the outer side of the apertured wall, point A; while curve F represents the pressure at the inner side of the apertured wall, point B. It will be seen that a substantial pressure differential exists at the opposite sides of the apertured wall and that although the pressure within the mixing chamber (reflected by the pressure at point B) quickly rises to a value conducive to the rapid making of lather, it levels off before an obj ectionally high value is reached. Experience has shown that a back pressure of approximately one to one and one-half inches (1" to 1%) is optimum.
The graph of Figure 5 shows that with the gate closed and with or without the constriction of the apertured wall the pressure in the mixing chamber as manifested by the pressure at point B quickly rises above the desirable value. In this graph curve G represents the pressure at both points A and B when no constriction is present, curve H represents the pressure at point B and I represents the pressure at point A with the constricting wall 14 in place and the gate [3 closed.
Curve E of Figure 6 shows that without the constriction ofiered by the apertured wall and with the gate l3 open, the pressure within the mixing chamber is entirely too low for rapid lathermaking, and With this condition the pressure at point A as represented by curve D, of course, is still lower.
By the use of the Venturi-like constriction afforded by the apertured bailie and the placing of the baflle back from the mouth of the discharge spout the lather stream issues from the spout at about the same rate and thickness or cross sectional size as the barbers have been accustomed to receiving from lathermaking machines. A smaller or slower travelling stream would be regarded as deficient and generally objectionable.
The space within the discharge spout outwardly of the constriction, of course, should be long enough to allow the lather to accumulate therein prior to issuing from the spout, this result being promoted by the presence of the weir l6 and the flow characteristics of lather. Skin friction and a sort of tumblin action characterize this flow.
The baffie plate i 4 preferably is a stamping having an attaching flange l8 about its periphery except at its straight bottom edge l9 which is stiffened by a rib or bead 20. The flange l8 initially is flared as shown in Figure 4 so that when the baflle plate is pressed into position in the discharge spout it makes intimate contact with the walls of the spout. It is then secured in position in any suitable manner as by sweating or soldering the same in place.
From the foregoing description taken in connection with the accompanying drawings it will be readily apparent that this invention provides an important improvement in lathermaking machines and that it is particularly helpful in overcoming a diflicult servicin condition by elimihating the human element which heretofore had to be depended upon to assure satisfactory operation of such machines.
What I claim as my invention is:
1. A barrier positionable inside the discharge spout of a lathermaking machine to maintain a slight back pressure in the mixing chamber of the machine, comprising; a disc stamped from sheet metal and substantially round except for a straight edged portion which forms a chord to the generally circular edge of the disc, said straight edged portion having a reinforcing bead therein; a flange extending about the generally circular edge, said flange being slightly flared; and an aperture in the center of the disc about one-third the diameter of the disc.
2. In a lathermaking machine having a mixing chamber in which an aqueous soap solution is whipped into a lather: a spout leading from the mixing chamber and through which lather is adapted to be discharged from the mixing chamber; and a barrier extending across the spout in spaced relationship to the ends thereof, said barrier having a single aperture therein substantially smaller than the cross sectional area of the spout but large enough to allow a substantial amount of lather to flow therethrough, said apertured barrier providing a Venturi-like constriction in the discharge spout to cause a slight back pressure to build up within the mixing chamber during operation of the machine without reducing the volumetric flow of lather through the discharge spout, and the space within the spout outwardly of the barrier serving as an accumulator so as to assure that the stream of lather issuing from the spout will have a thickness substantially equal to the cross sectional area of the discharge opening at the end of the spout.
3. The structure set forth in claim 2 further characterized by the provision of a drain passage at the bottom of the barrier to allow for return flow of reliquefied soap back to the mixing chamber.
4. The structure set forth in claim 2 further characterized by the fact that the spout has a substantially uniform cross sectional area and that the area of the aperture in the barrier is approximately one-sixth the cross sectional area of the spout.
5. In a lathermaking machine: means defining a mixing chamber in which soap, water and air may be whipped into a lather; a lather discharge spout of substantially uniform cross sectional area leading from the mixing chamber; a power driven agitator in the mixing chamber for combining soap, water and air therein to form lather which accumulates in the chamber and forces its way out through the discharge spout; and means in the spout intermediate the ends thereof defining an abrupt constriction therein having a clear opening substantially smaller than the cross sectional area of the spout but large enough to allow a substantial amount of lather to flow therethrough, said constricting means minimizing the tendency of sudden pressure difierentials at opposite sides of the constricting means to interrupt lather formation in the mixing chamber.
ELLIS M. BROWN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,457,895 Campanella June 5, 1923 1,821,914 Wagener Sept. 1, 1931 1,969,386 Reichenbach Aug. 7, 1934 2,052,569 Jensen Sept. 1, 1936 2,234,631 Gohre Mar. 11, 1941