US3771450A

US3771450A - Clean fluid washing system for duplicating machines and the like

Info

Publication number: US3771450A
Application number: US00260101A
Authority: US
Inventors: J Cleybergh
Original assignee: AB Dick Co
Current assignee: AB Dick Co
Priority date: 1972-06-06
Filing date: 1972-06-06
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13

Abstract

A system for providing a clean fluid wash of a blanket cylinder surface in a duplicating system for each cleaning which utilizes a cage to carry a relatively movable cradle which has rotatably mounted therein a scrubbing roller and a transferring roller in contact with the blanket cylinder and a metering roller in contact with both of the aforementioned rollers to meter cleaning fluid being used, and a wiper to trap cleaning fluid and remove contaminant from the scrubbing roller during each blanket wash, and selectively operable after the blanket wash is completed to release the contaminated fluid in preparation for the next wash, the setting of all three rollers being adjustable to obtain optimum cleaning results.

Description

United States Patent [191 Cleybergh Nov. 13, 1973 1 CLEAN FLUID WASHING SYSTEM FOR FOREIGN PATENTS OR APPLICATIONS DUPLICATING MA INE CH 8 AND THE LIKE 1,560,855 3/1969 France 101/425 [75] Inventor: John Cleybergh, Chicago, 111. 748,233 10/1944 Germany 101/425 Assignee: A B. Dick p y, Ch cago n. 1,264,453 3/1968 Germany 101/425 1 Filed: June 1972 Primary Examiner-C1yde 1. Coughenour [21] APP] NOJ 260,101 Attorney-Peter S. Lucyshyn ReltdU.S.A l' t Dt W M a a [57 ABSTRACT [63] Contmuanon of Ser. No. 42,320, June 1, 1970,

abandoned. A system for providing a clean fluid wash of a blanket cylinder surface in a duplicating system for each [52] US. Cl. 101/425, 15/256.52 cleaning which utilizes a cage to carry a relatively [51] Int. Cl B411 35/06, B411 41/06 movable cradle which has rotatably mounted therein a [58] Field of Search scrubbing roller and a transferring roller in contact 101/423-425; l5/256.5l, 256.52, 256.53 with the blanket cylinder and a metering roller in contact with both of the aforementioned rollers to meter [56] References Cited cleaning fluid being used, and a wiper to trap cleaning UNITED STATES PATENTS fluid and remove contaminant from the scrubbing rol- 511,934 1/1894 Cottrell 101/425 let durmg each blankel wash and Selecmely Operable 2 465 160 M1949 Levenhagen et al 101/424 X after the blanket wash is completed to release the con- 2I511I921 6/1950 Keu er...............:::: 101/425 laminated fluid Preparatiml the next Wash, the 2,832,239 4/1958 Mitchell et 10|/425 setting of all three rollers being adjustable to obtain 3,303,779 2/1967 Giori 101/155 X optim m cleaning results. 3,468,248 9/1969 Giori 101/425 X 3,486,444 12/1969 Huck 101/155 x 3 Clam, 10 Drawmg w M u ,w //4 A W 17@ Il\\ E:. 1/" 1 I f J 1 /f M1555 -/Y\-- A, '95 E X \r F" I LIJ g, .r \l ll 7 g J2 M2 I" 7 I %y.@ /i/ a 52' /ir \Q 7 '1 1 h l I 1 s I ll 1 A? if m PATENTED NOV 1 3 I873 SHEET 1 UP 5 PATENTEDMIHB 1973 3771.450

PATENTEU NIIY l 3 I973 SHEET 30F 5 HHHHU ul-I'll! CLEAN FLUID WASHING SYSTEM FOR DUPLICATING MACHINES AND THE LIKE This application is a continuation of Ser. No. 42,3 20, filed June 1, 1970, now abandoned.

BACKGROUND OF THE INVENTION Duplicating machines, for example of the offset type, have a master cylinder for carrying a master printing sheet, a blanket cylinder for receiving an inked image from the master sheet and an impression cylinder to transfer the inked image from the blanket cylinder to a copy sheet. Each time that a run using a master has been completed; i.e., the desired number of copies have been made, the machine must be prepared for the next master printing sheet to be run. One of the preparation steps is removal of the image from the blanket surface on the blanket cylinder. Customarily, the blan ket cylinder is wrapped with a rubber pad particularly adapted to receive an inked image from the master. Removal of the image from the blanket surface is described in the art as blanket cleaning.

Prior art blanket cleaning arrangements have used various systems for applying cleaning fluid to the blanket cylinder. One example presently used by the A. B. Dick Company, assignee of the present invention, is a Model 369 in which a wick is positioned to carry cleaning fluid from a trough up to a scrubbing roller. Another system, that of U.S. Pat. No. 3,102,470, uses a roller partially immersed in a trough of cleaning fluid communicating with another roller, the latter roller contacting the blanket cylinder surface to transfer solvent to the blanket and carry contaminant back to the trough.

One common aspectof the prior art systems is that the same trough used to store the cleaning fluid also serves to catch the ink contaminant. The cleaning fluid progressively fills with contaminant. In the high speed, automated duplicating machines which are adapted to duplicate a stack of masters, and thus involve many blanket washes, one after each master is run, the accumulation of ink in the cleaning fluid is rapid. Accordingly, only the first cleaning gives a truly uncontaminated blanket wash.

Another common aspect of these prior art systems is that an operator has to handle the dirty cleaning fluid. Because the job is undesirable, it is likely that the reservoir of cleaning fluid is not serviced and replenished with new fluid as often as is necessary to give good printing results. Furthermore, it is often necessary to run inferior copies before the effects of excessive contaminant in the blanket wash is realized.

BRIEF SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved surface cleaning system for use in a duplicating machine which assures a clean fluid wash at each cleaning so that the quality of each surface cleaning is the same.

It is a further object of the present invention in accordance with the above to provide an improved surface cleaning system which effectively cleans the surface with a relatively small amount of cleaning fluid so that drying of the surface can be effected quickly.

It is an additional object of the present invention in accordance with the above to provide an improved cleaning system that allows contaminated fluid to drain after each cleaning without the necessity of the operator handling the dirty fluid.

It is a more detailed object of the present invention in accordance with the above to provide a blanket cleaning system having an improved support for a blanket scrubbing assembly to permit accurate selection of the contact with the blanket surface so as to effect thorough and reliable cleaning.

It is an overall object of the present invention in accordance with the above to provide an economically manufacturable and easily adjustable cleaning system that is particularly adapted for installation on duplicating machines to quickly and reliably remove contaminants from a surface.

Other objects and advantages of the invention will become apparent upon reading the following description and upon which:

FIG. 1 is a side elevation of a cleaning system embodying the present invention adapted to be installed on a well-known three cylinder type offset duplicating machine;

FIG. 2 is a side elevation with the support structure at one end removed showing the cleaning system disengaged from the duplicating machine blanket cylinder surface;

FIG. 3 is a side elevation like FIG. 2 showing the cleaning system engaged with the duplicating machine blanket cylinder surface;

FIG. 4 is a rear elevation taken along line 44 in FIG. 2 to show a set of rollers and supports;

FIG. 5 is a plan view showing a frame assembly for the cleaning system;

FIG. 6 is a plan view of a cradle assembly drawn in aligned relationship with the frame of FIG. 5 of the cleaning system;

FIG. 7 is an enlarged view showing details of a roller support assembly for the cleaning system, there being one assembly provided at each of the opposite endslof the rollers;

FIG. 8 is a side elevation of one end of the cradle assembly of FIG. 6;

FIG. 9 is an enlarged elevation, in section, showing details of a pump adapted for use with the cleaning system of FIG. 1; and

FIG. 10 is a fragmentary rear elevation showing a detail of one end of a wiper adapted for use with the cleaning system of FIG. 1.

Turning to the drawings and the preferred embodiment introduced in FIG. I, thereshown is an offset duplicating machine 10 having a set of rotatable cylinders, a master cylinder 11, a blanket cylinder 12 and an impression cylinder 14. In the normal operation of the offset duplicating machine a master sheet (not shown) is wrapped around the master cylinder 11 and has ink applied to certain image areas in a well-known lithographic process. The inked image is transferred to a rubber pad or blanket 15 wrapped about the blanket cylinder 12. Duplicate copies of the master are made by the impression cylinder 14 carrying copy sheets and pressing them against the blanket cylinder 12. After the desired number of copies have been made from a master, the latter is ejected and the machine prepared to make copies of a new master. To that end, the inked image on the blanket 15 must be removed or cleaned up.

In accordance with the present invention a cleaning assembly is selectively engaged with the surface of the blanket cylinder, with a predetermined quantity of cleaning fluid being fed to the assembly so that surface contaminants are scrubbed or removed and carried away. As herein illustrated, the blanket cleaning assembly 20 is mounted on a pair of mounting brackets 21, 22 (see FIG. 4) the latter are fastened to the machine and the cleaning assembly is disengagable from the brackets. To facilitate mounting of the cleaning assembly, the brackets are each provided with a set of posts, post 24 carried by bracket 21 and post 25 carried by bracket 22.

The cleaning assembly 20 is selectively movable between an engaged and disengaged position by energizing a solenoid 26. The latter is coupled through a bell crank 27 to operative structure in the cleaning assembly 20, as is explained subsequently.

The interrelationship of parts in the cleaning assembly is now explained. Turning to FIG. 5 and describing the structure within which the cleaning system is carried, a pair of opposite

side frame members

28, 29 are held in spaced apart relationship by three longitudinally extending

tie rods

30, 31, 32 to define a cage.

As a feature of the present invention a pair of

rollers

33, 34 are floatingly supported in the cleaning assembly so that even pressure can be applied to the blanket cylinder 12 by each roller, and variations in the shape of the blanket cylinder surface can be accommodated. Yet, the structure maintains pressure on the other roller even if one roller is inoperative, for example if one roller drops into a blanket cylinder recess 37 provided for mounting the blanket. To that end the rollers are carried by a pair of pivotably supported links or

beams

35, 36, each beam being supported on a pintle, 38 and 39, respectively. Each pintle has longitudinal portions of circular cross section adapted to fit into oblong apertures 40, 41 (see FIGS. 2, 3 and 4) in respective stationary brackets 28, 29 (see FIG. 4). Thus, the

beams

35, 36 can both pivot with respect to the

stationary brackets

28, 29 and move slideably or longitudinally relative thereto. However, the degree of pivotal movement permitted for the

beams

35, 36 and consequently the rollers carried thereby is limited. That is explained subsequently.

To selectively transmit pressure to the

rollers

33, 34 and selectively engage and disengage them with the blanket cylinder 12, in the present instance a cradle assembly is provided within the afore-described frame or support cage. The cradle assembly (see FIG. 6) includes a pair of

side plates

42, 43 held in spaced apart relationship by a tie rod 44. Each of the forward or roller ends of the

respective plates

42, 43 are sandwiched together with the respective roller carrying

pivotable beams

35, 36. However, as is described subsequently, the assembly does allow slight relative movement between the

cradle side plates

42, 43 and the links or beams 35, 36. The sandwiching together in the present instance is accomplished by both the afore-described

posts

38, 39, and suitable fastening means carried by ends of

roller shafts

44, 45 respectively. Since the supports for the opposite ends of the

rollers

33, 34 are the same, only the left-hand side in FIG. 4 is shown in detail in FIG. 7. Describing the structure of the post 38, an inside end is provided with a stepped annular construction to define a pair of bosses 46, 48. Beam is supported on boss 46 and plate 42 is supported on boss 48. A nut 46a is threadably carried by the post 38, and upon tightening, it sandwiches the beam 35 and the cradle plate 42 together against an annular shoulder 49. Also holding the beam 35 and cradle plate 42 together are a set of dowel screws 50, 51 received in suitably tapped and threaded apertures 52, 54 of lower rol ler shaft 44 and upper roller shaft 45, respectively. In

' the exemplary embodiment the

shafts

44, 45 are stationary, and the

rollers

33, 34 are rotatably carried thereon by suitable bearings, for example sleeve bearings (not shown). Each dowel screw has a

boss portion

55, 56 respectively, closely fitting into complementarily shaped receiving apertures 58, 59. Thus, the

roller shafts

44, 45 and the

beams

35, 36 are held together in a somewhat rigid manner and are pivotable substantially as a unit about

posts

38, 39. Accordingly, if the shaft 44 pivots toward the viewer in FIG. 7, shaft 45 pivots a like amount away from the viewer. The

cradle plates

42, 43 at the opposite ends of the blanket cleaning system, however, do not permit unlimited pivotal movement of the roller shafts about the

respective posts

38, 39.

To permit only a limited amount of pivotal movement, the

cradle plates

42 and 43 have oversized openings to receive

shafts

44, 45, respectively. Only the details of the cradle plate 42 are shown, however, cradle plate 43 would be formed with complementarily shaped openings to receive in the

same manner shafts

44, 45 at the opposite end.

An opening 60 is adapted to receive shaft 44 and opening 61 is adapted to receive shaft 45. For permitting flexing between the cradle plates and the roller shafts while firmly supporting the shafts, respective 0-

rings

62, 64 are fitted over the ends of

shafts

44, 45, and received in the openings 60, 61, respectively. The latter-are tapered so that when the beam 35 and cradle plate 42 are sandwiched together the O-rings are retained. Accordingly, the cradle plates can actuate the

rollers

33, 34 positively against the blanket cylinder 12 by acting on

roller carrying beams

35, 36, the rollers are somewhat floating by virtue of the O-ring mounting to seek a position wherein even pressure is applied by each roller to the cylinder surface 15. This is because of the pivoting action by

beams

35, 36 occurring when one roller encounters a greater force which causes the other roller to be pressed more firmly against the cylinder and thereby even out the pressure applied by each roller. In addition the O-ring mounting acts as a shock absorbing mechanism during engagement of the system, as well as when the rollers ride through the recess 37 once each revolution. It has been found that the resilience of the O-ring must not be too low, a rating of ninety durometers has been found to be advantageous in one application.

To aid in maintaining the cradle assembly aligned as it is engaged and disengaged with the blanket cylinder, in the present instance the dowel screw heads, two of which 65, 66 are shown, are selected so that the overall longitudinal dimension of the movable cradle assembly is about equal to the distance between

opposite frame members

28, 29. The fit is, of course, with sufficient clearance so that no binding occurs as the cradle as sembly is moved relative to the frame members.

In the exemplary embodiment the lower roller 33 acts as a scrubbing roller while the upper roller 34 acts as a transfer roller. To that end, the lower roller is provided with complementary camming surfaces 68, 69 (see FIG. 4) at opposite ends thereof which engage rotatable guides 70, 71 supported on upright studs 72, 74

mounted on inwardly turned cars 75, 76 integral with beam 35 and beam 36, respectively. The upper roller 34 is provided with axial spacers 77, 78 at its opposite ends. Accordingly, the roller 33 oscillates axially applying a scrubbing action as drive is transmitted to it by the rotation of blanket cylinder 12, while the roller 34 remains in substantially one axial position as drive is transmitted to it by the rotating blanket cylinder.

As explained, the front ends or portions of the

cradle plates

42, 43 adjacent the

rollers

33, 34 are supported by the

respective posts

38, 39 carried in apertures provided in the blanket cleaning assembly side frames 28, 29. To support the rear portions of the

plates

42, 43 for pivotable and slidable movement, each cradle plate is provided with a slot, a slot 79 in plate 42 and a slot 80 in plate 43, adapted to receive a cam drive shaft 81. (See FIGS. 2, 3, 4, 6 and 8.) As is described subsequently in the exemplary embodiment the cam drive shaft 81 is selectively operable to actuate the cradle assembly and

plates

42, 43 toward, or to release and retract the

plates

42, 43 from the blanket cylinder 12.

Describing the supporting and actuating structure for the cam drive shaft 81,

suitable journals

82, 83 are provided on respective side frames 28, 29 to receive oppolsite ends of the shaft 81. At end 81a a bell crank 84 is mounted on the shaft. The bell crank 84 is provided with a projecting pin 85 having a head 85a adaptedto be received in a keyhole slot 86 of a linkage 87 (see FIG. 1). The latter is pivotably carried on bell crank 27 by suitable means, for example a pin 88, the latter also providing a mounting for one end of a spring 89 which is on the machine frame 10. Accordingly, the linkage 87 is connected to solenoid operated bell crank 27, previously described, which is pivotably operable about a pin 91. When energized the solenoid 26 acts on bell crank 27 and linkage 87 against the action of the biasing spring 89, so as to operate bell crank 84 and pivot cam drive shaft 81. Thus, when energization of the solenoid 26 is discontinued the spring 89 returns the linkage 87 to its normally biased position. As is explained subsequently, that releases the cradle assembly and

plates

42, 43, and permits them to return and carry the

rollers

33, 34 to a rest position disengaged from the blanket cylinder 12.

Describing the structure for selectively moving the

respective plates

42, 43 toward the blanket cylinder 12 (see FIGS. 2, 3, 5 and 6) the tie rod 44 is provided with a pair of adjusting

screws

100, 101 having chamfered

heads

102, 104 respectively. For engaging with the latter, a pair of

arms

105, 106, disposed generally at opposite ends of the cam drive shaft 81 and fastened thereto, are provided with respective camming surfaces 108, 109 one on each arm. FIG. 6 is set forth in line with FIG. 5 to show the relationship of the cage in respect of the cradle it carries for relative movement. The cam surfaces 108, 109 define respective lobe portions so that when shaft 81 is pivoted clockwise (see FIG. 3) the respective screw heads 102, 104 are acted on and the cradle assembly including the

plates

42, 43 and the tie rod 44 are laterally moved toward the cylinder 12. The

rollers

33 and 34 are pressed against or engaged with the blanket forming respective contact surfaces or bead lines 110 and 111 (see FIGS. 3 and 4).

It is an additional feature of the present invention that selective adjustment by which the screw heads 102 and 104 extend rearwardly (see FIG. 6) the width of the bead lines (see FIG. 3) and the alignment of the bead lines (see FIG. 4) can be selected. Thus, even if there are some irregularities in the blanket cylinder surface, flne adjustments can be made in the positioning of the rollers to effect thorough cleaning. In one practical instance a bead line of one-eighth inch gave the desired results.

As a further feature of the present invention the amount of cleaning fluid applied to the blanket is accurately metered so that cleaning is effected with a small amount of fluid permitting fast drying after the wash. To adjust the amount of cleaning fluid transferred to the blanket 15, in the exemplary embodiment a metering roller 112 is provided. The roller 112 is preferably formed of a suitable non-porous material such as stainless steel as compared to the relatively

porous cleaning rollers

33, 34 which are made of a rubber. As is shown in the drawings the

rollers

33, 34 are spaced apart and do not contact each other. The metering roller 112 is supported so as to fit between and engage both of the rollers, being supported for floating movement. As shown in FIGS. 2 and 3 there is a crevice between the lower roller 33 and the upper roller 34. Thus, if the metering roller 112 is held against falling out of the crevice it will be partially supported by the

rollers

33, 34.

Describing the support for the roller 112, it is provided with

suitable bearings

114, 115 at its opposite ends against which a pair of

pivotable levers

116, 118 act to press the metering roller 112 against the cleaning

rollers

33, 34. The

levers

116, 118 are pivotably supported on

pins

119, 120 attached to the respective

cradle side plates

42, 43. To facilitate operation of the

levers

116, 118 suitable spacers 121, 122 are provided between the levers and the cradle side plates.

To apply a biasing force to the upper end of the

respective levers

116, 118 thereby applying rotating force in a generally clockwise direction about the respective pivot pins 119, 120, respective biasing springs 124, 125 are connected to each of the upper ends of the

levers

116, 118. As herein illustrated, the biasing springs 124, 125 are wrapped about a suitable support means, for example collars 126, 128 (see FIG. 5) having annular grooves for receiving the springs.

To relieve the pressure of the metering roller 112 on the

rollers

33, 34, when there is no rotation so as to prevent flat surfaces being formed, the biasing action of

springs

124, 125 is counteracted by providing the

levers

116, 118 with projecting

ears

130, 131 adapted to engage

respective studs

132, 134 mounted on the side frames 28, 29 (see FIGS. 2, 5 and 6). The

ears

130, 131 and

studs

132, 134 engage when the cradle

assembly including plates

42, 43 and tie rod 44 are retracted. At that time the biasing force of the

respective springs

124, 125 is removed from the

levers

116, 118 and the lower end of the levers pivot counter-clockwise as viewed in FIG. 2 so as to release the metering roller 112. The latter is still held in the crevice between

rollers

33, 34, however, not under spring force. The crevice defined by the

rollers

33, 34, is sufficient to prevent the roller 112 from dropping, however, to facilitate assembly the

levers

116, 118 are provided with a hooked lower portion, one of which 135 is shown in FIGS. 2 and 3.

It is a feature of the present invention that clean fluid is conveyed to the

rollers

33, 34 each time that the blanket cleaning assembly is brought into engagement with the blanket cylinder 12. To this end, there is provided a fluid conveying system including a pump 150. The illustrated pump is particularly adapted to provide a metered amount of cleaning fluid to be directed to the

rollers

33, 34. The pump herein illustrated (see FIG. 9) includes a cylinder or barrel 151 carrying therein a piston 152 provided with a suitable sealing ring 154 and a fluid receiving aperture 155 in the head of the piston 154. The aperture 155 is selectively opened and closed by a ball-type check valve 156. The aperture and check valve communicate with a port 158 which extends through the center of the piston 152 to an end 159 adapted to receive a tube 160, which connects the pump 150 with a nozzle 161 feeding the cleaning fluid to the rollers 33, 34 (see FIGS. 2 and 3). The lower portion of the pump 150 is provided with an integrally formed cylinder head 162, the latter having a suitably formed protuberance 164 adapted to receive a tube 165 which can be connected with a source of cleaning fluid (not shown). Included in the cylinder head 162 is another ball check valve 166.

Describing the operation of the pump, when the piston 152 is drawn upwardly a vacuum is created because the check valve 156 blocks the aperture 155 which draws fluid past the other ball check valve 166. Thus, a shot of fluid is drawn into the cylinder 151. The amount of fluid drawn is determined by the stroke of the piston 152. On the down stroke of the piston 152 the check valve 156 permits fluid to be released while the check valve 166 blocks fluid flow. Thus fluid is squeezed or forced through the port 158 and tube 160 and directed to the

cleaning rollers

33, 34.

To actuate the piston 152 a slideable collar 168 is carried on a longitudinal portion 169 between respective lower and upper retaining walls 170, 171. The collar 168 is coupled to arm 106 (see FIG. carried by the cam drive shaft 81 In the present instance the collar 168 is provided with an integral drive pin 172 which has a groove 174 adapted to receive a retaining ring 174a. A shoulder bushing 175 having a threaded portion to carry a nut 176 is received on the pin 172. The bushing and nut are adapted to be tightened in engagement with the arm 106. The latter is provided with a slot 178 so that the radial position of the drive pin 172 with respect to the cam drive shaft 81 can be adjusted.

Accordingly, the stroke of the piston 152 can be selected to provide the desired amount of cleaning fluid each time that a shot of fluid is fed to the

rollers

33, 34 for cleaning the blanket. To permit the pump cylinder or barrel 151 to pivotas the stroking is effected, in the present instance a bracket 177a mounted on frame side 28 carries a pair of set screws 177b, 1770, provided with tapered points received in complementarily shaped openings of the pump barrel wall.

It is another feature of the present invention that only a small amount of fluid is required to clean the contaminant and ink from the blanket 15. To that end the system is prepared to hold a shot of fluid prior to fluid being directed thereto. Describing the fluid holding system, included therein is a wiper assembly 180 (see FIGS. 2, 3, 8 and 10. As herein illustrated the wiper assembly 180 includes a longitudinally extending shelf portion 181 provided at opposite ends with integral, upwardly extending braces only one of which, 182, is shown. The latter extend generally transversely to the shelf portion 181 and are provided with respective slots, only one of which, 185, is shown (see FIG. 8) adapted to receive the cradle tie rod 44. The latter provides pivotable and slideable support for the wiper assembly 180.

The shelf 181 is adapted .to swing into intimate engagement with the roller 33. In order to provide a rubbing action between the roller 33 and the wiper shelf 181 as well as to provide a tight fit to prevent fluid from running out, the shelf 181 is, in the present instance, wrapped with a cover 188 suitably fastened at one end to the shelf, in the present instance by a plurality of screws, a representative one of which, 189, is shown, and then wrapped about the opposite end of the shelf 181, underneath the latter and connected by suitable means to stretching springs 191 (only one shown). It has been found in practice that the wrap or cover 188 can be formed of DuPont Fairprene which is a nylon fabric impregnated with buna N rubber. To increase the surface contact between the shelf 181 and the roller 33, an extending portion of the shelf 181 is arcuate in cross section (see FIG. 3) so that when the wiper is pressed against the roller 33 the elastic wrapper 188 stretches, receding into the pocket and wrapping about the roller 33. The shelf 181 can be formed of suitable rigid material, in practice a metal shelf has been used.

To bias the wiper against the roller 33 during the time that blanket washing is being effected, opposite ends of the meter roller biasing springs 124, are connected to the transverse wiper braces 182 (only one shown) by hooking the spring ends over suitable posts 192 (only one shown see FIGS. 8 and 10). Accordingly, the springs 124,125 act on the braces 182 to pivot the wiper around the cradle tie rod 44. The transverse braces of the wiper assembly 180 are provided with extending fingers 195 (only one shown) which engage the frame tie rod 31 and the action of the

springs

124, 125 pulls the fingers against the tie rod. As a result, when the cam drive shaft 81 is operated and the cradle

assembly including plates

42, 43 andtie rod 44 are moved-towards the blanket cylinder, the tie rod 31 remains stationary, so that the springs are stretched and bias is applied to the metering roller levers 116, 118 and also to the wiper transverse braces 182. Because the pivotal rotation of the wiper is restricted by the action of the fingers 195 against the stationary tie rod 31, the wiper shelf 181 is caused to pivot into engagement with the roller 33.

To prevent fluid from being lost before cleaning of contaminants from the blanket is initiated, fluid is not directed to the

rollers

33, 34 until after the wiper assembly 180 is engaged with the lower roller 33. In the present instance a plate 200 is disposed below the nozzle 161 to deflect fluid coming out in a stream and spread it along the length of the roller 33, and apply it to the latter, part way up the roller. To explain, the application as shown in FIG. 3, the blanket cylinder 12 is rotating in aclockwise direction and the

respective rollers

33, 34 are respectively driven by the blanket cylinder in counter-clockwise directions. The metering roller 114 being driven by

rollers

33, 34 rotates in a clockwise direction. Accordingly, fluid directed to roller 33 is carried up towards a crevice 201 between the metering roller 112 and the cleaning roller 33. The pressure of the metering roller 112 determines how much fluid is permitted to be carried around by the roller 33 to the blanket 15 on the blanket cylinder. A crevice of fluid is maintained between the metering roller 112 and the cleaning roller 33.

As herein illustrated, the roller 33 is permitted to oscillate or move back and forth along its axis so that it effects a scrubbing action on the blanket 15. The upper roller 34 does not oscillate. It acts like a transfer roller carrying ink contaminant from the blanket to the metering roller 112 and carrying some cleaning fluid around to the blanket 15 from the metering roller 112.

As was described previously, the cleaning fluid is not fed to the

rollers

33, 34 upon initial operation or engagement of the rollers with the blanket cylinder 12, in order to assure establishment of a trap for the fluid when it is applied. In the present instance that is accomplished by utilizing a lost motion movement of the collar 168 before the piston 152 is stroked downwardly and fluid is fed out by the pump. In that time the cradle is pressed toward the blanket cylinder 12, and the wiper shelf 181 and cover 188, are pressed against the roller 33.

It is a feature of the present invention that surface cleaning can be accomplished very quickly. In one practical example 3.2 seconds, or the equivalent of 6 to 8 revolutions of the blanket cylinder, were permitted to wash and dry the blanket before the next image was applied to the blanket. Because of the relatively small amount of fluid necessary to accomplish cleaning and the relatively rapid evaporation rate of the fluid used, the present cleaning system met the requirements. One example of a practicable contaminant solvent is a combination of 55 per cent by weight hydrocarbon solvent and 45 per cent perchloroethylene.

Describing generally the working or cleaning action, at relatively high speed operation of the duplicating machine 10, the cleaning fluid will stay in the crevice between lower roller 33 and metering roller 112. At slower speeds the cleaning fluid will tend to cascade up and down the rear surface of the lower roller 33.

The upper roller 34, in the present instance, acts like a transfer roller. It picks up a certain amount of ink or image off the surface of the blanket and carries it back to the metering roller. The ink or image is carried by the metering roller to the crevice between the metering roller and the bottom scrubbing roller, where the ink is washed off. The pressure of the metering roller assures the proper amount of cleaning or washing fluid application to the blanket surface 15 on the cylinder 12. In one practical instance, sufficient pressure by the metering roller 112 to establish a sheen on the blanket surface 15 has been found desirable. This is a relatively small amount of fluid, sufficient to slightly moisten the surfaces of

rollers

33, 34. It has also been found desirable in practice to manufacture the

respective rollers

33, 34 with a rubber surface. Using a rubber impregnated material for the wiper wrap or cover 188 assures a frictional action between the wiper 180 and the scrubbing roller 33 which contributes a fast and effective wash of the contaminated surface.

Upon release of the cradle assembly, including

plates

42, 43 and tie rod 44 the wiper shelf 181 is permitted to retract from the lower scrubbing roller 33.

While the cleaning is effected, the elastic wrap 188 is maintained in rubbing engagement with the roller 33 and acts to remove contaminants that were picked up by the roller 33 from the blanket 15. There are some drippings produced in this manner which run off the end of shelf 181. However, most of the contaminated fluid flows away when the

rollers

33, 34 are disengaged from the blanket cylinder 12. At that time the wiper shelf 181 is permitted to retract from the lower scrubbing roller 33, and the fluid which normally is held in crevice 201 is released and flows down into a suitable contaminant receiving trough 202. The latter is disposed below the rollers and wiper so as to catch any drippings which are released from above. The contaminant fluid is directed into a sump 204 and carried by a suitable tube 205 to the contaminant collecting container.

The illustrative embodiment includes a shield 210 extending across the top of the blanket washing assembly overlying the

rollers

33, 34 and 122.'The splash shield is connected at its opposite ends to the

beams

35, 36 by suitable mounting screws, one of which 211 is shown. Generally centrally positioned of the splash shield 210 is a bracket assembly 212 adapted to hold the nozzle or spout 161 for directing cleaning fluid to the rollers. As exemplary shown the bracket 212 is fastened by suitable means, for example a screw 214 to the splash shield 210 and is provided with a U-shaped portion 215 with respective aligned apertures in the legs of the U to receive the nozzle 161 which is held in place by a set screw 219.

To permit manual operation of the blanket cleaning assembly the lever is provided with a handle 220. By swinging the handle 220 in a downward or clockwise direction the blanket washing assembly is made operative, the

respective rollers

33, 34 being biased against the blanket 15 and the fluid being pumped to the rollers.

To permit easy installation and removal of the cleaning assembly 20, there are pivotable latches 221, 222 carried on the frame sides 28, 29 adapted to selectively swing into hooked engagement with posts 24, 25 carried by the mounting brackets 21, 22.

As has been described the present blanket cleaning assembly is easily installed on a machine to clean the surface of a blanket cylinder or the like. The adjusting screws 100, 101 are set so as to establish a predetermined bead line where the

rollers

33, 34 contact the blanket 15. It has been found that by adjusting the

screws

100, 101 so that just a fine sheen appears on the blanket surface indicating a very thin film of fluid is carried thereon, that blanket washing is effectively accomplihsed with a small amount of fluid, for example 3 centimeters. It has further been found that by providing the pivotal carriage for holding the

rollers

33, 34 including the use of the O-ring supports at each of the four journaled locations, the rollers are held in a stable manner and with uniform pressure while accommodating for imperfections that may be present in the alignment or contour of the engaging surfaces of

rollers

33, 34 and blanket cylinder 12. That includes major variations in contour such as recess 37. Furthermore, because of the relative speed with which engagement is effected substantial shock is encountered by the rollers and the described structure operates to absorb the shock thereby keeping parts in adjustment longer and giving overall longer life.

While the invention has been described in connection with one specific embodiment and method, it is to be understood that this is by way of illustration and not by way of limitation. The scope of the invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit.

I claim as my invention:

1. In a duplicating machine having a surface laden with liquid removable contaminants, a surface cleaning assembly for removing the contaminants during a cleaning cycle comprising in combination a ftame; a washing roller made of elastomer material carried by said frame and engageable with the surface to be cleaned to form a bead line, said roller normally operating in a predetermined direction of rotation; a metering roller carried by said frame and engageable with said washing roller in advance of said bead line of engagement between the latter and the surface to be cleaned; a wiper carried by said frame positioned below said metering roller for engaging said washing roller subsequent to said bead line of contact between said washing roller and the surface to be cleaned; said wiper arcuately shaped to overlay a predetermined peripheral portion of said washing roller upon engagement of said wiper and said washing roller and carrying an elastomer material to contact said elastomer washing roller and provide a rubbing action to clean said washing roller, said wiper having a portion extending generally upwardly in said direction of rotation away from said wiper and roller engagement portion to form a fluid reservoir; means for introducing cleaning fluid for application to said washing roller, at least a part of said cleaning fluid collecting in said reservoir; means for selecting the pressure between said metering roller and said washing roller to permit a metered quantity of cleaning fluid to be transmitted from said fluid reservoir by said washing roller to the surface to be cleaned, said washing roller carrying a metered quantity of cleaning fluid to the surface to be cleaned and transferring contaminants mixed with cleaning fluid to said wiper for removal to prepare said washing roller for pick up of additional fresh cleaning fluid for transmittal to the surface to be cleaned; and means for disengaging said wiper from said washing roller to dump said cleaning fluid after each cleaning cycle.

2. The combination of claim 1 wherein said means for introducing cleaning fluid includes means for metering a predetermined quantity of cleaning fluid for use during each cleaning cycle.

3. The combination of claim 1 including means for adjusting the width and alignment of said bead line formed by engagement of said washing roller and the surface to be cleaned.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION patent 3,771 ,450 Dated November 13 1973 Inventor) John Cleybergh It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 26, should read Dick Company, assignee of the present invention, is in a Column 3, line 67, should read A nut 46 is threadably carried by the post 38, and Column 4, line 14, should read tially as a unit about

posts

38, 39. Accordingly, if line 24, should read tails of cradle plate 42 are shown, however, cradle Column 7, line 61, should read FIGS. 2, 3, 8 and 10). As herein illustrated the wiper as- Column 8, line 16, should read fabric impregnated with buna "N" rubber. To increase line 60, should read ler 112 being driven by

rollers

33, 34 rotates in a clock Column 9, line 5, should read carrying ink or contaminant from the blanket 15 to the Column 10, line 7, should read nant fluid is directed into a sump 204 and carried away by a line 46, should read complished with a small amount of fluid, for example line 47, should read 3 cubic centimeters It has further been found that by provid- Signed and sealed this 3rd day of September 1974.

(SEAL) Attest:

MCCOY M. GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 3 JRM Po 1050 (10 69) USCOMM-DC 60376-P69 W U. 5, GOVERNMENT PRINTING OFFICE l9? 3G6-33l,

Claims

1. In a duplicating machine having a surface laden with liquid removable contaminants, a surface cleaning assembly for removing the contaminants during a cleaning cycle comprising in combination a frame; a washing roller made of elastomer material carried by said frame and engageable with the surface to be cleaned to form a bead line, said roller normally operating in a predetermined direction of rotation; a metering roller carried by said frame and engageable with said washing roller in advance of said bead line of engagement between the latter and the surface to be cleaned; a wiper carried by said frame positioned below said metering roller for engaging said washing roller subsequent to said bead line of contact between said washing roller and the surface to be cleaned; said wiper arcuately shaped to overlay a predetermined peripheral portion of said washing roller upon engagement of said wiper and said washing roller and carrying an elastomer material to contact said elastomer washing roller and provide a rubbing action to clean said washing roller, said wiper having a portion extending generally upwardly in said direction of rotation away from said wiper and roller engagement portion to form a fluid reservoir; means for introducing cleaning fluid for application to said washing roller, at least a part of said cleaning fluid collecting in said reservoir; means for selecting the pressure between said metering roller and said washing roller to permit a metered quantity of cleaning fluid to be transmitted from said fluid reservoir by said washing roller to the surface to be cleaned, said washing roller carrying a metered quantity of cleaning fluid to the surface to be cleaned and transferring contaminants mixed with cleaning fluid to said wiper for removal to prepare said washing roller for pick up of additional fresh cleaning fluid for transmittal to the surface to be cleaned; and means for disengaging said wiper from said washing roller to dump said cleaning fluid after each cleaning cycle.