US2835234A - Device for improved cleaning and analysis of engine cooling systems - Google Patents

Description

May 20, 1958 c. H. RASCH ETAL 2,335,234

DEVICE FOR IMPROVED CLEANING AND ANALYSIS OF ENGINE COOLING SYSTEMS Filed May 6, 1955 2 Sheets-Sheet 1 INVENTORS C14 L RAsc/land ALTR SW /N @uuo,

ATTORNE Y8.

May 20, 1958 c. H. RASCH EI'AL 2,335,234

DEVICE FOR IMPROVED CLEANING AND ANALYSIS OF ENGINE COOLING SYSTEMS Filed May 6, 1955 2 Sheets-Sheet 2 IN V EN TORS jf: CARL /7. R145 C H 8/70 M41. TEE SW4 //v ATTORNEYS.

Unite rates Patent DEVICE FOR IMPROVED CLEANING AND ANALYSIS OF ENGINE CBOLING SYSTEMS Carl H. Rasc'h, North Tonawanda, and Walter Swain, Colden, N. Y.

Application May 6, 1955, SerialNo. 506,614

12 Claims. (Cl. 12341.42)

The present invention generally relates to devices and methods used to recondition and analyze the cooling .systems provided in internal combustion engines, or the like, particularly those used for motivating automobiles and other transportation means.

An object of the present invention is to provide animproved device of simple compact construction having means integrated therewith to permit easy detachable connection of the device to engine cooling systems and various pressurized air and water supply arrangements to establish controlled fluid channeling means therebetween for reconditioning such systems.

A further object of the present invention is to provide an improved device as aforesaid having transparent means fitted in predetermined positional relation to its surrounding elements so as to permit visual monitoring of the coolant fluid channelled through the device .to determine the condition of the cooling system and for locating various defects so as to determine the type of repair required to eliminate losses in efliciency in cooling of the engine, all without disconnection or rearrangement after the initial set up, as more particularly described hereinafter.

A still further object of the invention is to provide an improved method of servicing engine cooling systems without removal of the thermostatic by-pass valve means usually provided therein, the method including admittance of a controlled quantity of pressurized water and air into the cooling system at predetermined points of entry therein in relation to the thermostatic by-pass valve means for controlling the coolant fluid temperature and thereby the action of such valve means to selectively channel the path of fluid flow in the system while intermittently agitating the fluid at various temperatures by injecting the pressurized air into various parts of the system as determined by the position of said by-pass valve means.

A still further object of this invention is to provide an improved cast or molded device embodying a combination of fluid fiow control elements sealed for example in a plastic composition casing for holding these elements in correctly alined, leak-proof condition under even rough handling conditions for use accordingto the method of the invention.

A still further object object is to provide a device of the aforesaid type which is especially adapted for use in carrying out the method of the invention and which is simple to manufacture by mass production methods and will result insubstantial savings in materials and labor.

Still further objects and advantages of the present invention will be apparent in view of the specification set forth hereinafter.

In the drawings:

Fig. l is a top plan view showing the preferred form of the device of the present invention;

Fig. 2 is a front elevational view of the-device illustrated in Fig. 1;

Fig. '3 isa sectional elevational view .takenalongthe zline III--IH of Fig.1;

Fig. 4 is a sectional elevational view taken along the line IV-IV of Fig. 1;

Fig. 5 is a side elevational view schematically showing, partly in section, a common form of engine together with a reduced plan view of the device of Fig. 1 connected thereto;

Fig. 6 is a top plan view schematically showing the arrangement of Fig. 5 with the device of Fig. l embodied therein being shown in one operative condition thereof;

Fig. 7 is a reduced top plan view schematically showing the device of Fig. l in another operative condition thereof;

Fig. 8 is a view similar to the arrangement of Fig. 6 schematically showing the device of Fig. 1 embodied therein in another operative condition thereof;

Fig. 9 is .a view similar to Fig. 7 with the device thereof in still another operative condition.

Referring now more particularly to the embodiment of the invention illustrated in the drawings, a tubulartransparent member 1 5 of predetermined diameter is shown to be fitted at its opposite ends in fluid-tight relation into spaced T members 14 arid 16. These T members 14--16 areeach preferably fitted onto the inner end of a pair of threaded nipples 18 and 20 having their respective outer end portions 22 and 24 circumferentially undulated for the purpose of providing a convenient detachable leakproof connection for a pair of flexible hose members .26 and 28, as most clearly shown in Figs. 1 and 2.

The central portion of the T member 14 (Fig. l) is formed into an extended portion 34 provided with an aperture 36 extending therethrough and beingfitted at its outer end onto a threaded nipple member 38. The outer end portion of the nipple 38 is formed into an undulated portion 40 for the purpose of providing a detachable leak-tight connection with a hose member :42 through which will be supplied a suitable source of superatmospheric air pressure for the purposes outlined hereinafter in actual operation of the device of the invention (Figs. 1, 2 and 3).

The central portion of the T member 16 (Fig. .1) "is formed with an extended portion 46 connected by means .of a nipple member 48 to a fluid shut-off valve 50 (Figs.

land 4-) which connects to another nipple member 52 provided at its outer end portion with a suitable hose coupling 54 for detachable connection to a hose 56 through which may be supplied water at normal faucet pressure.

For the purpose of .controliing the circulation of the coolant and flushing fluid bypassed through the flexible ,conduitsZti andZS from the engine cooling system, a fluid circulation control valve 58 (Figs. 1 and 3) will befitted centrally ofthe 'i' member 14 with its valve stem portion 6t) preferably laterally related to the tubular portion 34. In addition, a suitable spring-pressed push-button type air check valve 62 (Figs. 1 and 3) will be fitted in the portion 34 ofthe T member 14 for the purpose of selectively controlling the supply ofpressurized air through thepassage .36 during operation of the device of the presentinvention. This passage 36 will communicate through a passage 64 .(Figs. 1 and 3) and around the valve seated (Fig.3) -in the body of the circulation control valve 58 fitted into the .theabove arrangement the passage 34 will be placed into communication with the engine cooling system through :both the hose connections 26 and 28 with thevalve 58in open position for permitting the operations described l below.

Thus, it 'isa particuiar featureof the present invention .that the.elementstsettforth abovemay be arranged in such Patented May 20, 1958 a manner as to be adapted to be permanently set by casting or molding in a suitable plastic composition body 70, or the like, preferably as shown in Figs. 1, 2, 3 and 4. This member 70 will be provided with a recess 72 (Figs. 1 and 2) for exposing a portion of the transparent'tube for the purpose of providing a transparent means through which the condition and rate of flow of the fluid in the engine cooling system may be observed by an operator of the present device.

The member 70 may be made in any suitable form preferably provided with a planar bottom surface, as most clearly shown in Figs. 3 and 4, onto which may be affixed a hard rubber pad 74 having its bottom face serrated for the purpose of providing a supporting surface which will permit the present device as embodied within the body 70 to be placed upon a planar work surface where it will resist movement thereon due to the high coeflicient of friction of the rubber and the serrated face thereof during operation of this particular form of the invention.

A further feature is that in actual use according to the method of the invention, the hoses 26 and 28 may usually be simply connected to the engine 80 (Figs. 5, 6 and 8) by fitting the hose 26 onto the heater water return connection (not shown) generally provided in the engine water pump, and the hose 28 onto the heater inlet connection 82. For simplicity the hose 26 is schematically shown to be connected by means of a T connection 84 to a radiator fluid return hose connection 86 (Figs. 5, 6 and 8).

Thus, by virtue of the arrangement as embodied within the casing member 70, the selective admittance of water and air under pressure into various parts of the engine 80 will be easily controlled as more particularly set forth hereinafter simply by adjustment of the valves 50, 58 and 62 without requiring any change in the existing arrangement of parts after the initial set up, and therefore resulting in considerable saving of the time required to recondition and test an engine cooling system.

A water inlet connection 88 near the top of the radiator 90 will communicate through a flexible hose 91 with a thermostatic valve housing 92 fitted onto the top of the engine 80 in a manner well known in the art (Figs. 5, 6 and 8). At the bottom of the radiator 90 there is provided a radiator outlet connection 94 for establishing communication, through the hose 86 with the water pump 98 provided at the forward end portion of the engine for forced circulation of the coolant and flushing fluid through the engine cooling system.

As shown in Fig. 5, a thermostatic valve 102 is fitted within the aforesaid housing 92 so that when the heat transfer fluid in the engine water jacket 103 is heated to a certain predetermined temperature this valve will open to permit passage of this fluid through the radiator in the usual manner. The water pump drive shaft is integrally connected to a fan belt pulley 104 and a fan 106 with the fan belt being customarily driven by a pulley 108 mounted on. a shaft 110 that is powered by means of any suitable gear connection to the engine crankshaft.

In operation as schematically indicated in Fig. 6, a cooling system flushing operation will be accomplished by first opening the circulation control valve 58 to permit bypassing of the heat transfer fluid in the engine through the hoses 26 and 28, and then admitting a controlled quantity of water under pressure into the engine cooling system through the valve 50 so as to maintain the temperature of the coolant fluid high enough to keep the thermostatic valve 102 open, the excess fluid during this flushing operaion overflowing out of the radiator in the usual manner. The admittance of this above controlled quantity of water under pressure through the water valve 50 when in its slightly open position of adjustment will cause entry of water into the water jacket 103 (Fig. 5) wherein it will follow various flow patterns and eventually will pass upwardly through the hose 91 into the radiator 90 and out. The system will simultaneously be purged with the pressurized air source by depressing the push-button of the air check valve 62 for the purpose of further agitating the coolant fluid flowing through the cooling system to loosen and break up any encrustments formed on the walls thereof and any sediment, or the like, which may have settled therein.

Another feature of the present invention is that changes in the adjustment of the water shut-off valve 50 will vary the temperature of the coolant fluid in the cooling system of the engine to permit air purging thereof with variations in temperature by simple mechanical control procedures. This has proved to more effectively clean the cooling system by placing more foreign matter in suspension with the coolant fluid for flushing out during the reconditioning operation.

After flushing in the above manner, the system will be easily reverse purged by simply closing the circulation control valve 58 as shown in Fig. 7 whereupon the flow of water through the flexible conduit 26 will be cut off sothat by further opening of the valve 50 the engine temperature may be reduced sufliciently to close the thermostatic by-pass valve 102. In this condition a purge of the system by pressurized air will automatically be effected in the direction of the hose 26 and up through the radiator to further aid the cleaning process, the application of the air being employed for a sufficient duration to blow some water out of the radiator through the opening 112 and the hose 114 connected thereto so as to lower the level of the fluid in the radiator to permit addition of a predetermined quantity of a special alkaline solution, after which the circulating valve 58 will be opened again for the purpose of permitting circulation of this solution for about 20 minutes at a temperature of about F. under the influence of the pressure developed by the water pump 98, or until the change in the color of the solution indicates that the proper amount of chemical activity has occurred. This special alkaline solution may include an inhibited sodium or potassium hydroxide compound with an indicator and surface wetting agent. The indicator will be a chemical agent which will react with the alkaline components in the solution to measure the degree of chemical activity of the latter with any foreign matter in the cooling system by the color change in the solution so that as it passes through the tube 10 it will be visually inspected during the reconditioning operations to gauge the effectiveness thereof and for reasons set forth with more particularity hereinafter.

After circulating the special alkaline solution in the above manner, the system will be flushed out with clear water in substantially the same manner as described above for the initial flushing stage. However, in this latter instance additional reversals of the direction of flow of the water may be required so that substantially all traces of the special alkaline solution will be removed from the cooling system perparatory to continuance of the operation.

At this point some water will again be blown out of the cooling system to make room for the addition of a special acid solution through the radiator filler opening 112 and with the valve 58 open and valve 50 closed (Fig. 9) the fluid in the system will again be circulated for about twenty minutes at a temperature of about 170 F. or until the change in color of the mixture indicates again that the proper amount of chemical activity has occurred. The acid solution may include an inhibited hydrochloric or muriatic acid concentrate with a chemical activity indicator and a surface active wetting agent. Then, the system will again be flushed with water to remove all traces of the acid solution, at which stage the cooling passages should be substantially free of all foreign matter with a resulting increase in the efficiency of engine operation.

Upon completion of the aforesaid process and before any change is made in the mechanical arrangement, clear Water will again be circulated through the cooling system and the device 70 with its circulating valve 58 in open position (Fig. 9) for the purpose of permitting visual monitoring of this water as it flows through the transparent tube 1d. One large oval bubble filled with smoke formed in the water and passing intermittently through the tube 10 will indicate what is commonly termed a blow-by condition in the engine; that is, a burned head gasket or other condition permitting a leak between the combustion and head valve chambers whereby combustion gases escape into the cooling system.

On the other hand, a chain of small interconnected oval bubbles flowing through the tube 10 will indicate a .creeping head condition; that is, a head not sealed onto the engine block due to the retaining bolts having lost their required torque either as a result of engine vibration or warping of the head. However, a chain of small round bubbles flowing through the tube 10 will indicate air leaks in the cooling system, in which event repairs may be made by the various chemical agents available for sealing such leaks. Then, after tightening the head bolts and effecting a chemical seal where air leaks are indicated, further visual observation will indicate whether the trouble has been corrected, and if not, the need for more drastic measures will be apparent.

Furthermore, it will be appreciated that a properly functioning thermostat will cause the circulation through the transparent tube lit to be slow when the coolant is cold and at full flow when it becomes hot for the reason that progressively higher temperatures cause the thermostatic valve to become more fully open and thus progressively increase the quantity of coolant fluid in circulation as is well'known. Thus, if the rate of flow of the circulation of the water through the tube It) is observed not to follow this above pattern, it will indicate a poor or faulty thermostat which should be replaced. In the event of a worn water pump, the observer will note that the circulation of the coolant through the tube 10 will be good when the water is cold and will be slow or will stop when the water is hot. A loose fan belt will be indicated in the event that circulation of water through the transparent tubular member 19 appears to be uneven as by passing therethrough in spurts event after the engine has become warmed up.

Thus, it is believed to be apparent that a still further feature of devices made in accordance with the present invention is that relatively inexperienced garage personnel during the cooling system reconditioning operations may be able to locate and easily repair may defects which may be in such systems as a result of mechanical defects in the engine, or else, to advise the engine owner as to specific repairs that may be needed to place the engine in good running order and thereby saving the owner what might otherwise be a costly repair.

It will be appreciated that another feature of the pres ent invention is that after the initial connections as in the manner noted above no further connections therewith need to be made during the cooling system flushing, cleaning, and analyzing procedures. Thus, there will result considerable savings in time and labor during reconditioning and trouble-shooting operations and for locating any possible defects is engine cooling systems which might cause a loss in efiiciency, or an inoperative condition.

Therefore, while I have particularly described one form of the present invention, it will be appreciated by those skilled in the art that the invention is not so limited but that various modifications and changes may be made therein within the scope of the present invention and the fol- .lowing claims.

.a supply of water under pressure, said device being arranged for detachable connection to the: outer ends of a pair of hose members leading thereto from communication at their opposite ends at spaced points with the interior of said engine cooling system, a passageway provided through said device to establish communication between these outer ends of said hose members, first means at one end of said device communicating with said passageway therein for selective supply of said water under pressure therethrough, second means at the other end of said device also communicating with said passageway therein for selectively supplying said air under pressure therethrough, valve means interposed in said passageway at the juncture thereof with said second means for controlling the flow of fluid through the passageway, and a transparent wall portion being provided in the passageway so as to be integral therewith and being arranged to be visible from one side of said device for permitting visual inspection of the condition of the fluid flowing through said passageway after circulation through the engine cooling system.

2. A unitary coupling device for use in flushing and analyzing engine cooling systems, in combination with an engine cooling system, a supply of pressurized air, and a supply of water under pressure, said device having a first fluid passage therethrough, said first passage includ ing a transparent window portion substantially centrally thereof which is arranged to be visible from one side of said device to permit visual inspection of any fluid pass ing through said passage, a second fluid passage within said device extending from one end of said first passage and out through a side of the device, a third passage within said device extending from the opposite end of said first passage and out through a side of the device, the respective outlets of said passages being provided with detachable hose connection means, a pair of hose members being connected at the opposite ends of said first passage and extending away therefrom for connection to the engine cooling system to establish communication therewith, said supply of pressurized water being connected to the outlet of said second fluid passage, said supply of superatrnospheric air being connected to the outlet of said third passage, an air check valve being embodied in said coupling device third passage, a water shut-oi? valve being embodied in said coupling device in said second fluid passage, and a circulation control valve being embodied in said coupling device at the juncture of said first and third passages, said control valve having air by-pass means to permit passage of pressurized air through one of said hose members even when said circulation control valve is closed, whereby cleaning, flushing and cooling system analysis will be accomplished without rearrangement of the connections prior to completion of the entire operation.

3. A device for use in cleaning and analyzing engine cooling systems comprising, in combination, an engine I cooling system, a supply of pressurized air, a supply of Water under pressure, fluid conduit means provided with a transparent central portion being fitted at one end thereof to a fluid circulation control valve having an upstanding stem portion, the opposite end of said fluid conduit means being fitted to a T member, a pair of spaced substantially parallel tubular portions being provided to extend from said circulation control valve and said T member, respectively, both being in communication with the interiors of their respective body portions and in substantially lateral relation to the stem portion of the former, said supply of pressurized air communicating with thetubular portion fitted into said control valve, said supply of Water under pressure communicating with the other tubular portion, a spring-pressed air check valve for selectively permitting controlled charges of pressurized air into the engine cooling system through the interior passageways of said circulation control valve which will be arranged to permit passage of air in both directions through said control valve when in open position and in only one direction when said control valve is in closed position, a water shut-ofi valve for selectively permitting flow of pressurized water into the engine cooling system, and a casing member, the aforesaid elements being arranged in substantially coplanar relation so that said casing will permanently embody the other elements, said casing having a recess in its upper face to expose said transparent central portion of said fluid conduit means to permit visual examination of the condition of the fluid passing therethrough during an engine cooling system cleaning and analyzing operation.

4. A unitary coupling device in combination with an engine cooling system, said device having a body member provided with transparent fluid conduit means therein having a medial portion thereof exposed to view at one side of said body member, the opposite ends of said conduit means having detachable connection means for communication thereof with said engine cooling system, superatmospheric air supply means provided for communication through an air passage interiorly of said body member which communicates with one end of said conduit means therein for selectively applying charges of air into the cooling system, a fluid circulation control valve being provided in said body member at the juncture of said air passage and transparent fluid conduit means for controlling the flow of fluid and pressurized air thereat, pressurized water supply means being provided for communication through a water passage in said body member which communicates with the opposite end of said transparent fluid conduit means therein for selectively supplying flushing water into said engine cooling system.

5. A composite engine flushing device, in combination with a source of fluid under pressure, a source of air under pressure, and an engine having a coolant fluid circulation system, said device including detachable connection means at its periphery for communication with the interior of said engine cooling fluid circulation system and for selectively channeling said pressurized fluid and air therethrough for circulation in various flow patterns incidental to cleaning and analysis thereof, and transparent connection means embodied within said device and being visible from exteriorly thereof for permitting visual observation of the rate of flow and the condition of the cooling system fluid channeled through said device.

6. A unitary coupling device, in combination with an engine cooling system, a supply of water under pressure, a supply of air under pressure, said device including spaced hose connection portions arranged for detachable connection of the respective ends of a pair of hose members, each of said hose members leading thereto from connection at spaced points of said engine cooling system for communication with the interior thereof, a fluid passage being provided through said device between said spaced hose connection portions, first means in communication with one end of said fluid passage for selectively supplying said water under pressure therethrough, second means in communication with the other end of said fluid passage for selectively supplying said air under pressure therethrough, valve means interposed in said fluid passage at the juncture thereof with said second means for controlling the flow of fluid, and a transparent wall portion in said fluid passage, said Wall portion being arranged to be visible from one side of said device for permitting visual inspection of the condition and rate of flow of the fluid in said fluid passage.

7. A composite engine cooling system coupling and test device, in combination with a coolant circulatory system of an engine, a pressurized air source, and a pressurized water source, said device including a fluid passage therethrough having a transparent Wall portion intermediate the ends thereof to permit visual inspection of the condition of any fluid passing beneath the inside face thereof, first detachable connection means at opposite ends of said fluid passage for establishing communication With said coolant circulatory system of said engine,

, with a coolant circulatory system of an engine, said device comprising a body member having a fluid passage therethrough, a wall portion of said body member intermediate the ends of said fluid passage forming a part thereof and being transparent, detachable connection means at the opposite ends of said fluid passage being in communication with said coolant circulatory system of said engine, superatmospheric air supply means provided for communication through an air passage interiorly of said body member which communicates with one side of said fluid passage therein for selectively applying charges of air therein, a fluid circulation control valve being provided in said body member at the juncture of said air passage and said fluid passage for controlling the flow of fluid and pressurized air thereat, pressurized water supply means being provided for communication through a water passage in said body member which communicates with the opposite side of said fluid passage for selectively supplying flushing water into said circulatory system of said engine.

9. A composite engine cooling system coupling and test device in combination with a source of air and fluid under pressure, and an engine having a fluid cooling system, said device including detachable connection means at its periphery for communication with the interior of said engine cooling system and for selectively channeling fluid and air therethrough for circulation in various flow patterns incidental to cleaning and analysis thereof, a fluid passageway being provided to channel said air and fluid under pressure between said connections, said passageway having a transparent wall portion visible from exteriorly of said device for permitting visual observation of the rate of flow and the condition of the cooling system fluid in the engine, and means, for selectively controlling the flow of said air and water through said passageway, whereby all flushing and testing operations in cleaning an engine cooling system may be performed without requiring any changes or rearrangement of said device after the initial set up.

10. An improved method of reconditioning the cooling system of an internal combustion engine having a radiator to which the flow of coolant fluid is controlled by a thermostatic valve, the method including regulating the temperature of the coolant fluid by admitting a controlled supply of water at one side of the thermostatic valve, then periodically injecting charges of pressurized air into parts of the cooling system at opposite sides of the valve with variations in the coolant fluid temperature for purging this coolant to loosen and break up any encrustments and sediment which may have formed in various parts of the system, then automatically directing the flow of pressurized air charges through the radiator as a result of admitting sufiicient water to lower the coolant temperature to a point where the thermostatic valve will close, then adding chemical solutions to the coolant fluid and circulating the mixture through the system for cleaning thereof, and

' then flushing the system with water and purging in the above manner to complete the cleaning operation.

11. An improved method of reconditioning an internal combustion engine cooling system placed in communication with a radiator to which the flow of engine coolant fluid is regulated by a thermostatic valve, the method including detachably connecting an external source of both water and pressurized air for selective communication with the engine cooling system at opposite sides of the thermostatic valve, respectively; these sources, together with the engine coolant fluid being selectively channeled through a transparent fluid passage for permitting visual inspection of the condition of the fluid passing therethrough; then admitting a controlled quantity of the water source to flush the cooling system and thereby varying the temperature of the coolant fluid therein, then periodically injecting charges of pressurized air with the variations in temperature to purge the system for mechanically loosening any encrustments or sediment formed therein, then admitting suflicient water to lower the temperature for closing the thermostatic valve and automatically causing a reverse purge of the system by further injection of pressurized air and then also blowing out 'fluid through the top of the radiator as a resutl thereof,

then shutting ofi said sources and adding to the radiator an inhibited alkaline solution containing a chemical activity indicator and a surface active wetting agent and circulating the resulting mixture throughout thecooling system, then flushing, purging, and again blowing out fluid from the radiator, then again shutting off the external Water and air sources and adding an inhibited acid solution containing a chemical activity indicator and a surface active wetting agent into the radiator and circulating the resulting mixture through the cooling system, then again flushing and purging in the above manner, and monitoring the operations by observing the condition of the fluid by-passed through said fluid passage to determine the progress at various stages of the reconditioning process.

12. An improved method of reconditioning an internal combustion engine cooling system having a radiator, a water pump, a radiator outlet hose connection from the bottom of the radiator to said pump, a fluid inlet radiator hose connection at the top of the radiator leading to the engine, a thermostatic valve located in said fluid-inlet radiator hose for controlling the flow of coolant fluid 10 therethrough, and a pair of water heater hose connections, the method including establishing communicaton between said water heater hose connections through a transparent fluid passage for permitting visual inspection of the coolant fluid by-passed therethrough for gaging the condition of the system, then selectively admitting external sources of water and pressurized air in either or both directions through said flushing hose, the supply of water being controlled to vary the temperature of the fluid in the engine while the pressurized air will be injected with such temperature variations to purge the system for mechanically loosening and breaking up any foreign matter therein, then admitting suflicient water to lower the coolant fluid temperature to a point where the thermostatic valve will automatically shut oil the supply of water to the radiator, then reverse purging the system by injecting charges of air into the flushing hose in the direction of the radiator and thereby also blowing coolant fluid and any'foreign matter in suspension therein out of the radiator, and then adding chemical solutions into the cooling system and repeating the above operations for flushing thereof to complete the cleaning operation.

References Cited in the file of this patent UNITED STATES PATENTS 103,872 Greene L June 7, 1870 944,611 Holmes Dec. 28, 1909 1,619,273 Sargent Mar. 1, 1927 1,701,824 Robinson Feb. 12, 1929 1,891,592 Fitz Gerald Dec. 20, 1932 2,092,257 Lewis Sept. 7, 1937 2,146,930 Bassett Feb. 14, 1939 1 2,221,803 Krobusek 'Nov. 19, 1940 2,264,876 Hackley Dec. 2, 1941

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