US2781535A - Sheet cleaning machines - Google Patents

Description

Feb. 19, 1957 w. l. PHILLIPS ETAL 2,781,535

SHEET CLEANING MACHINES Filed May 7, 1954 5 Sheets-Sheet l INVENTORS. MLL/AM 1 PH/LA/Pfi' BY JAMES a zAwe /vfl' Feb. 19, 1957 w. l. PHILLIPS ET AL SHEET CLEANING MACHINES 5 Sheets-Sheet 2 Filed May 7, 1954 INVENTORS MLL/AM Z PH/LL/P6' 17 1 455 C. LAWeENaE A r roe/V5145 Feb. 19, 1957 w. l. PHILLIPS ETAL 2,781,535

SHEET CLEANING MACHINES Filed May 7, 1954 5 Sheets-Sheet 3 III"- INVENTORS. WILL/AM I. PHILLIPS J/m s' a LAWEL-NC'E BY WMaW A r roe/w y:

Feb. 19, 1957 w. I. PHILLIPS ET AL ,78 35 SHEET CLEANING MACHINES Filed May 7, 1954 5 Sheets-Sheet 4 INVENTORS. W/LL/AM l. PH/LL/P' BY J4M5 mama/a? \o \Q I l A TTOEA/E V5 United States Patent SHEET CLEANING MACHINES William L Phillips and James C. Lawrence, Seattle, Wash., assignors to C & H Supply Company, Seattle, Wash, a corporation of Washington Application May 7, 1954, Serial No. 428,158

6 Claims. (Cl. -77) The purpose of the machine to which the present invention pertains is the removal of smut from sheets of material passed through it and is concerned particularly with the removal of smut such as masking ink from relatively small sheets of material.

The present machine was designed particularly to solve the problem of removing masking ink from small sheets of aluminum foil, one foot to one and one-half feet square, for example, utilized in the process of making metal foil labels, but the machine is not restricted to cleaning sheet material either of that type or that size. The construction and operation of the machine will, however, be described in connection with such a process.

A principal object of the invention is to clean such sheets, including feeding them to the cleaning machine, washing, scrubbing, rinsing and drying the sheets, and finally accumulating them, all without manual handling.

A further object is to utilize cleaning liquid efiiciently in the cleaning operation so that it will be sprayed directly upon each sheet, particularly for initial washing and rinsing, by timing the actuation of the sprays and travel of the sheet accurately, and arranging the flow of cleaning liquid so that rinsing of the sheet is accomplished with the cleanest liquid but initial washing will not utilize perfectly clean liquid. Conveniently, the cleaning liquid can be reconditioned for recirculation through the machine.

In the cleaning procedure it is an object to scrub each sheet firmly, though perhaps lightly, despite'the flimsy character of the sheet material.

Another object is to dry the sheet material after the rinsing operation during its travel through a short distance to keep the machine compact while moving each sheet at the same speed of travel as it moves during the washing and rinsing operations. f

An additional object is to segregate the rinsing liquid from the washing liquid eifectively despite uninterrupted movement from the scrubbing station to the rinsing station, so that the sheet will emerge as clean as possible with minimum reconditioning of the cleansing liquid.

A machine capable of accomplishing the foregoing objects may incorporate a sheet transport conveyor which will grip the leading edge of each sheet as it is fed automatically to such conveyor and will convey the sheet first through a washing station, then through a scrubbing station, next through a rinsing station, and finaly through a drying station, in series. Smut washing liquid or solvent will be sprayed on the sheet as the sheet passes the washing station and the rinsing station, and the spray will be interrupted as soon as the sheet has passed to conserve the solvent. The drying is accomplished by passing the sheet between squeegee rolls.

Additional objects and advantages of the machine will be discussed in the following detailed description of the preferred type of'machine illustrated in the drawings.

Figure 1 is a side elevation view of the sheet cleaning machine, and Figure 2 is a somewhat diagrammatic vie of the machine incorporating a piping diagram.

v 2,781,535 Patented Feb. 19, 1957 ICC Figure 3 is an enlarged side elevation view of the central portion of the cleaning machine with parts broken away, showing the scrubbing mechanism, and Figure 4 is a top perspective view of one portion of the machine with parts broken away to reveal scrubbing mechanism.

Figure 5 is a top perspective view of the section of the machine incorporating the rinsing mechanism, parts being broken away.

Figure 6 is a top perspective view of the section of the machine incorporating the drying mechanism and having parts broken away.

Figure 7 is a side elevation view of the same portion of the machine with parts broken away.

The sheet cleaning machine includes five principal sections, shown in Figure 1, namely an automatic feeding section 1, an initial washing section 2, a scrubbing section 3, a rinsing section 4 and a drying section 5. Through all of these sections sheets S are moved without interruption by a sheet conveyor 6. While the machine may be used for other purposes, it is very useful for removing from aluminum foil sheets smut in the form of masking ink, which is applied to the aluminum foil in the process of making aluminum foil labels.

In general the process of making such labels includes anodizing a sheet of "aluminum foil of approximately .003 inch in thickness, dyeing the anodized foil surface and maskingwith printers ink by a silk screen process the background of the sheet, etching the unmasked portions of the sheet to remove the color in the indicia portions, and then removing the maskingink. This ink is tenacious in its adherence to the sheet surface and is very messy to wash oil with ink solvent. Moreover, such altuninum foil sheets are rather fragile so that caremust be exercised in handling them while scrubbing the masking ink from their surfaces. By the use of the present machine cleaning of the sheets can be accomplished by production line technique which is entirely automatic, and at the same time is considerably more etficient than hand methods and conserves cleaning liquid.

The smut covered sheets are stacked on the feeding platform 10 of the automatic sheet feeding device 1,

which is a conventional printing press feeding device and tween them. The gripping bars are spaced apart along the conveyor far enough to leave ample clearance between successive sheets, but the particular spacing of such sheets is not of special significance. Various pro"- essing operations are coordinated with the sheet location so that successive treatments of each sheet occur in timed sequence. V i

In cleaning the smut from aluminum foil sheets of the type described, an ink solvent is used as the washing liquid. The first step in the cleaning process, therefore, is to spray on the ink-coated side of each sheet solvent which will begin to dissolve the ink. This initial washing spray operation occurs'in the washing section 2 of the processing tank, which preferably is closed onall sides except where the sheet-enters the tank at the feed end and is removed from the spray head only during passage of a sheet beneath it.

The processing tank as a whole includes raised feed and discharge end portions and a depressed central portion. All the liquid, therefore, tends to flow from the spray section down the inclined portion 23 to the central depressed portion. The conveyor 6 follows this path, being guided over guide sprockets 61 in the sheet feeding mechanism (Figure 1), then over sprockets 62 at the junction between the elevated feed end and the portion inclined downwardly in the direction of travel to the central depressed portion, and under sprockets 63 at the lower end of such inclined portion.

The fingers of the clamps on the gripping bars 60 are arranged in substantially coplanar relationship with the chain of the conveyor 6 and are long enough to exert a firm grip on the leading edge of an aluminum foil sheet despite the fragile nature of such sheet. As thechain passes from the downwardly inclined trough portion of the device, therefore, to its lowermost horizontal trough portion, the sheets S will trail behind bar 60 in generally horizontal position. In this scrubbing section 3 of the trough is at least one, and preferably two scrubbing stations through which the conveyor passes.

Each scrubbing station is separately covered by a hood 30 and includes a rotary brush 31 and a cooperating backing roll 32. The chain of the conveyor 6 passes over the backing roll. which has the upper portion of its periphery generally in horizontal alignment with an entrance aperture 33, through which the conveyor chain enters the housing 30, and an exit aperture 34. through which the chain of the conveyor leaves the housing. The backing roll is mounted on an axle 35 which also carries at opposite ends of the roll 32 sprockets 36 with which the conveyor chains engage to turn the backing roll 32.

The brush 31 is 'driven preferably by a motor 37 independent of the conveyor drive in a direction opposite the direction of rotation of the backing roll 32, so that the lower periphery of the brush moves in a direction counter to the direction of travel of the conveyor 6 and the foil sheets carried by it. Normally the smut is on only one side of the sheets being processed, which will face upwardly so that it is sufiicient for the scrubbing brush to contact only the upper face of the sheet. The speed of the motor 37, the drive ratio between such motor and the brush 31, and the diameter of the brush may be selected to efi'fect brushing movement of the lower brush periphery at any speed desired within wide limits.

As the foil sheets are drawn across the periphery of the backing roll 32,pressure of the brush on the upper sides of the sheets will not appreciably deflect the sheets or subject them to mutilating stresses While exerting an effective scrubbing force on the sheets. To accomplish this action it is necessary that the shafts of the backing roll and the rotary brush be located sufiiciently close together to effect an appreciable positive pressure of the brush against the backing roll or a piece of aluminum foil on it.

It is undesirable, however, for the sheet clamping bar 60, which is considerably thicker than the foil sheets, to be subjected to such vigorous scrubbing action and consequently the backing roll 32 has in it a longitudinal groove 38 of a width to receive such bar. The circumferential extent of the rollers 32 will be coordinated with the spacing of bars 60 along the conveyor chain so as to insure that each clamping bar will always register with a. groove 38, although it is not necessary that the conveyor have a clamping bar for each increment of length equal to the The bar spacing and sprayed with ink solvent. If desired, this washing section of the machine may contain sutficient solvent so that the foil actually is moved through a solvent bath during the brushing operations, but this may be unnecessary.

From the washing section the foil ascends through the upwardly inclined rinsing section 4 shown best in Figure 5 and then into a draining section. In the rinsing section the sheet S is carried between upper and lower rinsing spray pipes which spray ink solvent on the sheet. Preferably this section includes a plurality of upper spray pipes 40 and a plurality of lower spray pipes 41 which project spray onto both sides of the foil sheet to rinse otfthe dirty solvent.

Through this section extend upper wires 42 and lower wires 43 reasonably close to the conveyor 6 which restrict the fluttering movement of the foil sheets under the impact of the spray projected on them from the pipes 40 and 41. A plurality of these wires may be supported at intervals spaced transversely of the direction of movement of the conveyor by suitable mounting lugs 44 mounted on the partition walls 45 forming the opposite ends of the rinsing compartment. The conveyor moves the sheets into this compartment through an entrance opening 46 and out through a discharge opening 47. A window 48 may be incorporated in the side of the apparatus at the location of the rinsing chamber to enable an operator to observe the effectiveness of the apparatus at this point in completely cleaning the smut from the sheet.

After the sheet is rinsed it is carried on up the incline by conveyor 6, during which travel most of the rinsing liquid drains from the sheet. Such liquid, as well as that sprayed onto the sheet in the rinsing compartment, flows down the inclined bottom trough and through limber holes in the corners of the partitions 45 toward the washing compartment.

When the foil sheet reaches the drying compartment 5 shown in Figures 6 and 7, its path of movement preferably changes from upwardly inclined to substantially horizontal. The sheet moves into the drying compartment through the aperture 50 in the partition 51 which serves principally to stiffen the body of the apparatus. In the drying compartment is mounted the terminal shaft 64 of the conveyor 6 which preferably is the powered shaft to pull the conveyor chain by rotation of sprockets 65 over which such chain passes. The shaft may be driven by sprocket 66, turned by chain 67, which is driven by the motor 68 shown in Figure 1. This terminal shaft of the conveyor is reasonably near the entrance to the drying chamber.

From the end of conveyor 6 to the accumulating bin 7 the foil sheets are moved by a mesh belt conveyor 52, which uuderlaps' the discharge end of conveyor 6, The foil sheets must, of course, be released from the clamping bars in order to be carried by the conveyor 52, and such sheet releaseis eitected by a'stationary cam 69 which is engaged by a cam follower roller 69 carried by the clamp releasing arm of the clamp bar 60. The cant 69 is located adjacent to the return run of the conveyor 6 spaced slightly from the conveyor terminal shaft 64. Thus each foil sheet will be held clamped by its bar 60 until after the bar has traveled around the sprockets and the foil sheet S has been flipped beneath the conveyor by such action.

Because the sprockets 65 should be of considerable diameter as a practical matter, if a foil sheet were released while being carried by the upper stretch of conveyor 6, it would fall through a considerable distance before reaching the mesh conveyor 52 located beneath the sprockets 65. Also, if a foil sheet were released while being carried by the upper stretch of the conveyor, it would be necessary to release it well before the sheet reached the shaft 64 because otherwise the sheet would strike such shaft. Also there is a possibility that it would strike a clamping bar 60 on the lower stretch of the conveyor 6. By releasing the foil sheet when moving along the lower stretch of the conveyor rather than the upper stretch, the distance which the sheet must drop to the mesh conveyor 52 is kept to a minimum. Also, there is no possibility of the released sheet striking any interfering mechanism such as a clamping bar 60 or the shaft 64 during its travel to the mesh conveyor belt.

While the conveyor 52 has been described as a mesh conveyor belt, a different type of conveyor belt could be used if desired. The principal point of importance, however, is that the conveyor 52 atford a moving surface on which the foil sheet can lie for translation edgewise without being positively gripped in any fashion as it is when moved by the conveyor 6. The foil sheet transportation of this type is desirable so that the conveyor 52 can not only carry the sheet to but feed it edgewise between cooperating resilient surface squeegee rolls 53 located im mediately beyond the discharge end of the conveyor 52. The entering angle between these rolls should be sub stantially in alignment with the upper surface of the conveyor 52, as shown best in Figure 7.

The rolls 53 have their opposite ends mounted in a double pillow block mounting so that the roller shafts are held at a spacing to press the roll peripheries tightly together. As the sheet S moves edgewise between these rolls, therefore, all the ink solvent remaining on the foil sheet will be squeezed off it, so that the sheet emerges in a substantially dry condition and is discharged from the machine ready for storage or immediate further processmg.

It will be evident that belt 52 should not be driven appreciably slower than conveyor 6 unless there is considerable space between the clamp bars 61) of that conveyor. In any event it is essential that the speed of the conveyors 6 and 52 be coordinated to prevent the possibility of excessive accumulation of foil sheets on the latter. Such coordination can be effected most easily by driving the conveyor 52 from the drive shaft 64 of conveyor 6. The peripheral speed of the squeegee rolls 53 should also be substantially the same as the speed of conveyor 52, and it likewise may be driven from the drive shaft d4 of conveyor 6. The drives for rolls 53 and conveyor 52, then, may include the chain 55' interconnecting a sprocket 56 on drive shaft 64 and a sprocket 57 secured on the shaft of the lower squeegee roll. A chain 58 connects a sprocket at the other end of the lower squeegee roll to a sprocket integral with the roll 59 at the discharge end of belt conveyor 52.

In many cases the foil sheets S may be curled to a greater or lesser extent, and to insure reliability of their feed edgewise into the angle between the squeegee rolls, it is desirable to provide at least one and preferably a plurality of confining chains located above the carrier belt 52. While stationary guides probably would be of considerable assistance in this regard, movable confining elements such as the chains 70 are considerably more effective. The stretch of each of these chains adjacent to the upper surface of the carrier belt 52 is inclined toward the carrier belt in the direction of its movement.

A convenient and compact arrangement is to slope the upper stretch of conveyor 52 upward from beneath the discharge end of the conveyor 6 to a location adjacent to the infeed side of the squeegee rolls. The confining elements "7%) may then be inclined downward somewhat in the direction of their movement, as indicated in Figure 7, to form a passage convergent toward the entering angle of the squeegee rolls through which the foil sheets move.

(Jurled portions of the foil sheets engaged on opposite sides by the confining elements and by the conveyor 52 are gradually flattened until they are sufiiciently flat upon reaching the squeegee rolls as to be fed certainly between them. Since the squeegee rolls turn in opposite directions, as indicated in Figure 7, contact of the leading edge of a foil sheet with the rolls also will have the tendency to move the sheet edge into the angle between the rolls.

If the confining elements 70 are of the movable type,

it is desirable for the confining members and. the carrier conveyor 52 to move at substantially equal speeds; the drive of the confining chains, like the drive for the conveyor 52, may therefore come from the squeegee rolls 53. The particular arrangement shown incorporates a chain 71 powered by a sprocket 72 on the upper squeegee roll shaft which drives a sprocket 73 on the discharge end shaft 74 of the confining chains. This shaft carries sprockets 75 over which the confining chains run, and the opposite ends of such chains are carried by sprockets 76 on shaft 7'7. The degree of convergence between the confining elements 70 and the upper stretch of coin veyor 52 can, of course, easily'be altered by shifting the position of shaft 77 upward or downward.

Since the ink solvent utilized in'the operation of the machine described is rather expensive, it is desirable to use as little of such solvent as possible to do a thorough cleaning job. On the other hand, ifthe foil sheets were simply run one after another through a solvent bath which was only changed periodically, the thoroughness of the cleaning job would decrease continually until the cleaning operation did not give satisfactory results. Use of cleaning fluid is most effective at certain stages of the entire cleaning operation, and solvent could be conserved if it were used only at such selected points of the cleaning cycle. When all these factors are considered, however, too much solvent still is required to make the automatic cleaning operation economical, because when the cleaning operation is done by hand the operator can observe when the cleaning solvent being used becomes too dirty for continued use and can change it.

in the present machine, therefore, its operation is made practical, first by recovering used solvent by cleaning it; second, by supplying solvent only at the locations where it is most effective; third, by supplying such solvent at such locations only while a foil sheet is passing the particular solvent supplying station; and, fourth, clean solvent is used only for the final rinsing operation, and somewhat soiled solvent is employed for the initial stages of the cleaning operation. in order to accomplish this type of solvent utilization timing mechanism is provided which is coordinated with movement of the sheet conveyor so that the duration of the solvent dispensing action at each location is closely controlled.

The first soaking or washing spraywhich is delivered 7 by the head 24! can utilize reasonably dirty solvent and still be effective. Likewise, the additional washing spray 39 shown in Figure 3 can eject reasonably dirty solvent because these follow immediately a scrubbing operation in each case, so that they will float off smut mechanically and use the solvent properties primarily to dissolve this loosened smut to prevent the ink being deposited at the bottom of the trough. On the contra y, the solvent delivered to the final rinsing sprays '48 and 41 should be clean, although it may be recovered and recirculated solvent. 7

in Figure 2 the piping for the solvent is shown which delivers somewhat dirty solvent to the spray pipes 25) and 39, clean solvent to the rinsing spray pipes 40 and 41, removes used solvent from various portions of the tank and purifies the solvent forreuse. Startingwith the clean solvent in tank 8, a pump 80 delivers such solvent through pipe 81 to the rinsing spraypipes A li-and 41 from which the clean solventis sprayed onto scrubbed foil sheets, as described above. This liquid drains through the limber holes 49 of the partitions 45, as mentioned, into-a sump formed at the upper side. ofpartition 82, as shown in Figure 3. somewhat dirty solvent is withdrawn by gravity through pipe 83 into an intermediate storage tank 34.

From thetank 34 a pump 85 delivers the somewhat From this sump the of the tank to the central sump to which drain pipe 87 is connected. Since there are only three washing heads as compared to six rinsing pipes, it is probable that the rate at which rinsing solvent is used will exceed the rate at which the washing solvent is dispensed. Consequently, tank 84 would tend to receive partially used solvent at a rate faster than such solvent is withdrawn by pump 85. Any excess solvent thus accumulated in tank 84 flows out of it through the overflow pipe 88 into the pipe 87 mentioned above.

From pipes 87 and 88, the former of which collects very dirty solvent, the pump 89 delivers the dirty solvent through pipe 9 to the feed end of the solvent cleaner 90. r

The solvent cleaner 90 may be of any conventional evaporator construction and consequently is shown merely diagrammatically in Figure 2. As solvent continues to be pumped into the cleaner and is purified, it will overflow through pipe 91 and flow by gravity to the clean solvent supply tank 8. The tanks 8 and 84 will, of course, be of adequate capacity to hold enough cleaning solvent for operating the whole system when all the solvent has been drained from the tank in which the foil sheets are cleaned.

As mentioned previously, in order to conserve solvent it is desirable to dispense such solvent both at the washing stations and at the rinsing stations only at the time and for the duration during which a sheet of foil is being moved past such respective stations by the conveyor 6. To effect this operation the several spray pipes are controlled by solenoid-operated valves which are energized by switches of cam timing mechanism. Such cam timing mechanism shown in Figures 1 and 3 is coordinated with the movement of conveyor 6 carrying the sheets.

The spray timing mechanism includes rotary cam means preferably incorporating two can disks 100 and 101 mounted in coaxial side-by-side position on shaft 102 for rotation. These cam disks are driven by a chain 103 from sprocket 63 which is turned by movement of conveyor 6. Around the periphery of these cams are arranged solenoid valve control switches including switch 104 for the initial washing operation, switch 105 controlling dispensing of washing solvent at the scrubbing stations, and switches 106, 107 and 108 which respectively control the rinsing sprays.

The circumferential extent of the cam ridges with which the switch plungers engage determines the duration of solvent dispensing during each cycle. The circumferential location of such ridges establishes the point at which each spray operation begins and terminates. In order to select proper peripheral lengths of the cam ridges to elfect the desired control operation, the two cams 100 and 101 are arranged in side-by-side relationship, the former being engaged by the washing spray control switches 104 and 105 and the latter being engaged by the rinsing control switches 106 and 107. The switch 104 will be electrically connected to energize the solenoid of valve 22, and the switch 105 will be electrically connected to energize the solenoids of valves 109 which control the flow of solvent to the washing spray pipes 39 at the discharge side of the scrubbers. Switches 106, 107 and 108 are electrically connected respectively to the solenoids of valves 110, 111 and 112. Valve 110 controls the flow of solvent to the lowest pipe 40 and the lowest pipe 41, valve 111 controls the flow of solvent to the intermediate pipe 40 and the intermediate pipe 41, and valve 112 controls the flow of solvent to the highest pipe 40 and pipe 41.

From Figure 3 it will be seen that the sheets S moving in the direction indicated by the arrow are approaching the washing sprays 39. Correspondingly, the leading end of the cam rib on cam disk 100 is approaching the control switch 105 for the valves controlling the flow of solvent to pipes 39. As soon as the 11b of cam 100 rides under the plunger of switch 105, the switch will be moved from its normally open position into closed position, valves 109 will be opened, and solvent will be sprayed from pipes 39 onto the foil. Such dispensing of the spray liquid will continue until the switch plunger rides off the rib of earn 100, whereupon the trailing edges of the two sheets which have just emerged from the scrubbers will have passed beyond the respective spray pipes 39.

Before the sprays from pipes 39 have been shut off the rib of cam will have moved under the plunger of switch 104 to close this switch for eifecting energizetion of the solenoid valve 22 initially to spray washing fluid on another foil sheet just entering the machine. Because the same cam rib actuates switch 104 as actuates switch 105, the initial spray will continue for the same duration as the sprays from pipes 39. Also, the switch 104 will be placed at the proper location around the periphery of cam 100 so that the spray will start just before the sheet reaches the spray location and will be stopped as soon as the sheet leaves such location.

The position of the cam disks shown in Figures 1 and 3 does not correspond to the position of the sheet S shown in Figure 5. None of the switches 106, 107 and 108 is engaged by the rib of cam 101. As this cam is turned during approach of a sheet S to the rinsing spray section, however, the leading end of the rib on earn 101 will move beneath switch 106 to energize valve 110 and start the first sprays. As the sheet and cam continue to move, the leading end of the rib on cam 101 will move under the plunger of switch 107 to close such switch just before the leading edge of the sheet reaches the intermediate spray pipes. Similarly, the leading edge of such cam rib will move under the plunger of switch 108 as the leading edge of the sheet approaches the final spray pipes. The rib of cam 101 is of suificient circumferential extent that all three of the switches 106, 107 and 108 will be closed for a short time, so that all six rinsing sprays will be projected for a corresponding period onto the sheet. As rotation of the cam 101 continues, first switch 106, then switch 107 and finally switch 108 will be opened as they ride off the cam rib, so that successively the first, intermediate and last pair of upper and lower rinsing sprays will be deenergized as the trailing edge of the sheet leaves each pair of sprays.

The aluminum sheet being cleaned may in some instances be sufiiciently stiff to be suspended in substantially horizontal planar attitude when supported in cantilever fashion by one edge. The foil which the present device may be used to clean, however, is only .003 of an inch thick, so that a sheet a foot or so square, when held in cantilever fashion by one edge, would droop very considerably. Consequently, the conveyor 6 includes chains spaced apart a distance substantially equal to the width of the sheet being cleaned, as shown in Figure 5 and Figure 6, and sheet supporting rails are provided between these chains to support the foil sheets in generally planar shape. In Figure 3 the rails 113 support the sheet as it moves downward to the scrubbing stations, and between these stations the sheet is supported by the rails 114 which are shown both in Figure 3 and in Figure 4. Between the last scrubbing station and the rinsing station the sheet is supported by the rails 115, and the rails 116 shown in Figures 5 and 6 support the sheet between the rinsing section and the drying section 5.

We claim as our invention:

1. A sheet cleaning machine comprising a tank, conveying means operable to' move a sheet edgewise through said tank in succession through an initial washing station,

a scrubbing station, a rinsing station, and a drying station,

means at such initial washing station operable to supply liquid to the sheet, scrubbing means at the scrubbing station operable to engage and scrub the sheet during its movement by said conveying means, spraying means at said rinsing station operable to rinse the sheet, drying means at the drying station operable to remove moisture from the sheet, and timing means operable by said conveying means to initiate operation of said spraying means at the rinsing station substantially when such sheet reaches the rinsing station and further operable to terminate such operation of said spraying means substantially when such sheet leaves the rinsing station,

2. A sheet cleaning machine comprising conveying means operable to move a sheet edgewise through a spraying station, spraying means at said spraying station operable to spray liquid on the sheet, and timing means operable by said conveying means to initiate operation of said spraying means substantially when such sheet reaches the spraying station and further operable to terminate such operation of said spraying means substantially when such sheet leaves the spraying station.

3. A sheet cleaning machine comprising a tank, first conveying means operable to move a sheet edgewise through said tank and including chains spaced apart a distance substantially equal to the width of the sheet transversely of said chains, a clamping bar having its opposite ends connected to said chains, respectively bridging between them and operable to clamp the leading edge of the sheet, squeegee rolls beyond the discharge end of said conveying means, and second conveying means having one end underlapping the discharge end of said first conveying means and operable to underlie substantially the entire area of a sheet discharged by said first conveying means and operable to drivingly engage only the under surface of the sheet while the upper surface of the sheet is substantially free of driving engagement, to transport such a sheet to said squeegee rolls and into tractive engagement therewith for movement between said squeegee rolls to dry the sheet.

4. A sheet cleaning machine comprising a tank, first conveying means operable to move a sheet edgewise through said tank and including chains spaced apart a distance substantially equal to the width of the sheet transversely of said chains, a clamping bar having its opposite ends connected to said chains, respectively, bridging between them and operable to clamp the leading edge of the sheet, squeegee rolls beyond the discharge end of said conveying means, and mesh belt conveying means having one end underlapping the discharge end of said first conveying means and operable to receive a sheet discharged by said first conveying means and operable to drivingly engage only the under surface of the sheet while the upper surface of the sheet is substantially free of driving engagement, to transport such a sheet to said squeegee rolls and into tractive engagement therewith for movement between said squeegee rolls to dry the sheet.

5. A sheet cleaning machine comprising a tank, conveying means operable to move a sheet edgewise through said tank in succession through awashing station and a rinsing station, washing spray means at such washing station operable to spray cleaning liquid on the sheet during movement thereof through the Washing station by said conveying means, rinsing spray means at such rinsing station operable to spray rinsing liquid on the sheet during movement thereof through such rinsing station by said conveying means, washing spray solenoid valve means operable to control operation of said washing spray means, rinsing spray solenoid valve means operable to control operation of said rinsing spray means, rotary cam means driven by said conveying means in synchronism therewith, and switching means actuated by said rotary cam means and operable to control energization of said washing spray solenoid valve means and of said rinsing spray solenoid valve means to effect energization thereof only substantially during movement of the sheet by said conveying means through the washing station and through the rinsing station, respectively.

6. In a sheet cleaning machine, a plurality of spray means arranged in series, conveying means operable to move a sheet edgewise past the spray means of such series in sequence, a plurality of solenoid valves one for each of said spray means and operable to control each such spray means independently of the other spray means, rotary cam means driven by said conveying means in synchronism therewith, and switching means actuated by said rotary cam means and operable to energize said solenoid valves in sequence and to deenergize said solenoid valves in sequence to effect energization of each spray means substantially only during movement of the sheet past such respective spray means.

References Cited in the file of this patent UNITED STATES PATENTS 1,039,608 Spiess Sept. 24, 1912 1,943,775 Taylor Jan. 16, 1934 2,184,567 Rundell Dec. 26, 1936 2,313,606 Webb et al Mar. 9, 1943 2,372,599 Nachtman Mar. 27, 1945 2,374,668 Davidson May 1, 1945 2,380,550 Reed July 31, 1945 2,392,391 Kaddeland Jan. 8, 1946 2,467,423 Bruker Apr. 19, 1949

Images