US2781230A - Solution feed for a cleaning machine - Google Patents

Description

Feb. 12, 1957 c. L. PRITCHARD SOLUTION FEED FOR A CLEANING MACHINE Filed June 14,- 1954 I N V E NTO R Clarence LPr/fchara' United States Patent 2,781,230 SOLUTION FEED FOR A CLEANING MACHINE Clarence L. Pritchard, San Leandro, Califi, assignor to Malsbary Manufacturing Company, Oakland, Calif., a

The present invention relates to improvements in a solution feed for a cleaning machine of the character described in the Malsbary Patent No. 2,295,228, although the principle of the invention may be applied to other purposes.

The cleaning machine is intended generally for cleaning motor vehicles or heavy industrial machinery by means of a strong spray of hot water or steam having a cleaning solution embodied therein.

The machine comprises in its general features, a coil having means for heating the same, means for forcing water with an admixture of a cleaning solution through the coil, a hose connected to the discharge end of the coil and a discharge nozzle with a relatively small orifice at the free end of the hose.

In the patent, it is proposed to use a pump for forcing the water through'the coil, and the solution is fed to the pump from a suitable tank in a separate path and is mixed with the water in the pump.

It is advisable, however, in the interest of economy, and where conditions warrant, to connect the coil directly to a city Water supply, and in that case the feeding of the solution into the water becomes a problem which is the object of the present invention to solve.

In this connection it should be noted that the solution should preferably be fed into the water before it reaches the coil, because the solution has a beneficial effect in maintaining the coil in a clean condition. Since the present invention is directed principally to the solution feed, the parts of the cleaning machine not involved in the understanding of the invention have been omitted from the drawing, for the sake of simplicity.

Further objects and advantages of my invention will appear as the specification proceeds, and the new and useful features of my solution feed will be fully defined in the claims attached hereto.

The preferred form of my invention is illustrated in the accompanying drawing, forming part of this application, in which:

Figure 1 shows, in side elevation, the general layout of the invention;

Figure 2, a top plan view of my solution tank; and 1 Figure 3, a part sectional, part side view of the tank, the section being taken along line 3-3 of Figure 2.

While I have shown only the preferred form of the invention, I wish to have it understood that various changes or modifications may be made within the scope of the claims attached hereto, without departing from the spirit of the invention.

Referring to the drawing in detail, the solution tank 1 may be of any suitable form, and is preferably made cylindrical, and dimensioned to hold approximately one gallon of. the solution. It may be secured to the machine in any suitable manner, and is here shown as being secured upon the side of the coil housing 2 by means of suitable brackets 3.

It should be noted that the location of the tank with respect to the main conduit makes little diiference, since gravity feed forms no part of the invention.

The solution in the tank may be of any suitable mixture of water and cleaning compound, and may be assumed, for the purposes of the present invention, to have approximately the same specific gravity as the water fed through the machine.

In the general operation of the machine, it is intended that the solution be fed into the main flow of Water in a mere trickle, so that one gallon of solution will serve many gallons of water passing through the machine.

The cleaning machine, itself, is represented in the drawing by the conduit 4, which at one end, indicated at 5, is connected to a suitable source of water under considerable pressure, such as a city water supply, and at the other end, indicated at 6, to the heating coil of the cleaning machine. The latter again connects, through a suitable length of hose, with a discharge nozzle, so that the water passes through the coil under pressure and is discharged through the nozzle, either in the form of hot water or of steam, or of a mixture of both steam and water, depending upon results desired.

In the operation of the machine, it is desired that the water be fed at a constant volume, regardless of changes in pressure in the city water supply.

For the purposes of the present invention, I introduce a slight resistance in the conduit, which may take the form of a flap valve 7 pivoted in the conduit, as at 8, and having a light spring 9 bearing against the same and tending to close it. This valve creates a slight pressure differential which is utilized to by-pass a small amount of water from the main flow into the outlet pipe 10 which leads to the top of the tank and connects thereto through the aperture 11 in a cap 12 fitted into the upper end of the tank.

Immediately underneath the cap 12, and secured to the bottom thereof by means of a screw 13, is a bafiie 14 in the form of a disc which has a diameter slightly smaller than the inner diameter of the tank, so that the water entering through the pipe 10 first gently joins the liquid present in the space above the bafiie, and then causes the latter to gently feed around the periphery of the disc to join the liquid below the baffle.

The pipe 10 is provided with a metering valve 15 which may be set to meter out the water drop-wise, in a thin trickle, and I have found that Water thus entering the tank tends to remain on top of the solution in the tank, and does not mix with the latter.

The water merely forms a surface layer, which increases in size as the process is continued and develops into a piston which drives the solution through the aperture 16 in the bottom of the tank at the same rate that the water enters through the top.

The bottom aperture 16 connects through the return pipe 17 with the conduit 4 downstream of the resistance 7. Due to the fact that the water and the solution do not mix in the tank, all of the solution thus discharged into the conduit will be of uniform strength, and the tank will keep feeding solution of original strength until the solution is completely exhausted, and the whole tank is filled with water, at which time it becomes necessary to refill the tank with solution.

The connection 18 between the aperture 16 and the return pipe 17 is equipped with a shut-off valve operable by a handle 19 for disconnecting the tank from the return pipe in case a refill becomes necessary.

The bottom of the tank also has a quick-opening valve 20, which may be removed upon turning the handle through one-quarter of a turn, for effecting a quick draining of the water from the tank.

The top of the tank has a similar quick-opening valve 21 which is shown in detail as comprising a cylindrical a -3 valve-head Z'Z-fitting in an opening '28 in the cap and formed with a pair of tongues 24 adapted for anchoring underneath a pair of lugs 25 when the valve is turned By means bf haadl-esshownat 26; The valve be pulled out eateries of a turn offthfe Ban-ales iii-the appease d-irectioh, and the spelt-mg 23h urea used for re fillin'g th'e tank. a

The cdridui't I is cbhnected t6 the top bf the tank through a T-fitting 27 which is provided with breeder hole controllable through a handle -28 for v'e'iitirig' sue pisses. This venting becomes necessary, after the tank has been filled with solution to its limit and the valve 22*hasbeen rte-applied,- in order "to allow water f ibm the pips 10 to completely fill pockf's'forfiled in the can fietidhs asavetfi soIut-io'h level; V

It'w'fill be noted that the-portion brine bafiie oidisc 14 'dispb'sed underneath the filler hole i'sbent dbwhward; as at 1'4; This is tea the purpose 0? giving some aadi efial else-lance for the solhtiofi-dhring the filling operation; 1

In use, assuming that the tank has been properly filled with solution and that water is forced through the condfi-it 4 under high pressure, the resistance 7 will create a pressure differential which causes a small portion of the water to be lay-passed to the top of the taiik, the extra amount depending upon the setting of the metering valve '15, which is set to deliver a mere dribble of water to the tank. Y i The feeding of water is very gentle,- and the battle aids to efit such a smooth and gradual transfer of the water that the latter does not mix with the solution; but only forms agradually increasing layer of water above the solution with the result that the solution is crowded tliiftigh the conduit 17 into the conduit downstream of the resistance.

Thus, the solution is red into the flow of water at a rate. corresponding to the openingof the metering valve, and since the solution is not mixed with any water,- a solution of uniform strength will be fed into the conduit until the tank is emptied completely.

When all the solution has been fed; the tank is filledwater, and it is necessary: to re-fill the tankwith solution. This operation, the tank is first disconnected from the system by closing the valve 19. i

' Next the bottom valve 20 is removed to allow the water to drain out. This valve is then replaced, and the top valve- 21 is removed to open the filler hole,- whereupon the tank is filled with solutionto its capacity.

Next the va'lve' 21 is replaced, whereupon the metervalve I is operated to' allow the liquid from' the conduit to fill any existing voids, the vent 28 allowingtrappe'd air to" escape.

'Upoh reopening the valve 19 inthe bottom of the tank and proper setting of the metering valve; the tank is n'ov'd ready for further dispensing operations;

While the solution has been described as having ap proximately the same specific gravity as the water, it should be understood that its gravity is slightly higher than that of the water, the chemicals adding about one pound per gallon to the specific gravity.

1 claim:

1. In combination, a conduit having means for passing a liquid therethrough uhder pressure, a resistance in said conduit adapted to slightly impede the flow of the liquid therethrough, a bypass for the conduit including an outlet passage disposed upstream of the resistance, a return passage disposed downstream of the resistance anda tank connecting the; two passages, the tank having a -second liquid therein of approximately the same spe cific gravity the fi' i quid; the "outlet passage having unrestricted conn'ec tank, and the return passage being connected 1 whereby the first liquid is made to cause-the, second liquid to feed into the conduit the outlet and return passages being ceiiiictd fo' thecondtiit closely adjacent the resistance so as to render the inherent pressure drop in the conduit between the passages substantially negligible, n t ars n b n iau dz qm lled a l v ab estate n -y ,it jss i itq mammifimep esur differential i lt' h p sag s, ti e to t ire mfi e san ai s etime; sse fi d we sures, and-being sufficiently slight to cause liquid t ass through the by-pass in a gentle flow, and a Iii ering valve in" the outlet passag and operable to reduce the w wuafith gbx-r 'w v o.

on'duit having means for'pass git underpressure, a resist'ance t: flvli he b f passfor the conduitincluding g St ps re m ffih ta c ae mvia d o e downstr mx fthe x ist and a'tank connecting the twcipass'agels; the tank having 1 a se nd li ui t e n o ,ait fo i l i h S me 5P fi g at y he firs liq th l ass e. Ha in fi ir t' t d' wm Wi lie e of thet n a d e return passage being eon'nected to the bottom thereo'fi whereby the first liquid is'made to cause the second liqeid m fed into the conduit, the" outlet and r'emrn passtg'es bfeing connected to the conduit closely adjacent tl' lsi i sasid a qr ild t e mc t r s e p in thefconduit between" the pas-sage substantially negligible, and resistance being liquid-controlled' and variable in response to liquid pressure to maintain" the I pressure difierential betw en the two passages" due to the resist-'- ance substantially constant for different liquid pressures, and being suff ciently slight to cause Iiquidto pass through the bY-fpass'in a gentle flow, and a metering valve in the outlet passage and operable to reduce the fiow'through' the bypalssfto1 a" trickle", the tank having a; baffle under neatfr the outlet passage discharge toreduce disturbance of th'f liquid in th e tank due to the feed from the outlet passage to a minimum;

References Cited in the fi Ie" of this patent

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