US3897726A

US3897726A - Washing device for a blanket cylinder of an offset printing press

Info

Publication number: US3897726A
Application number: US470946A
Authority: US
Inventors: Rudi Junghans
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 1971-11-24
Filing date: 1974-05-17
Publication date: 1975-08-05
Anticipated expiration: 1992-08-05

Abstract

An offset printing press having a blanket cylinder includes a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional driving engagement with and traversible relative to the blanket cylinder, means for wetting the washing roller with wash solution, a collecting vessel underlying the washing roller, a doctor roller having a firm surface located in continuous frictional engagement with the washing roller, a doctor blade abutting the firm surface of the doctor roller for guiding therefrom into the collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having a firm surface engaging the soft covering of the washing roller at a location behind the doctor roller in the rotary direction of the washing roller, the distributor roller being wettable with fresh wash solution.

Description

United States Patent Junghans 1 1 Aug. 5, 1975 [54] WASHING DEVICE FOR A BLANKET 2,731,916 1/1956 Koch 101/425 CYLINDER OF AN 3,207,373 9/1965 Darmenmann v 1 1 1 1 222/517 X PRESS 3,656,200 4/1972 Riley l5/256.52 3,693,547 9/1972 Morgan 1. 101/425 [75] Inventor: gudi Junghans, Wilhelmsfeld, FOREIGN PATENTS OR APPLICATIONS ermany 1,169,668 11/1969 United Kingdom 101/425 [73] Assignee: Heidelberger Druckmaschinen 548,280 4/1932 Germany .1 101/167 Aktiengesellschaft, Heidelberg, Germ ny Primary ExaminerClyde l. Coughenour [22] Filed: May 17, 1974 Attorney, Agent, or FirmHerbert L. Lerner 1 1 pp bio-1470346 57 ABSTRACT Related U,S A li ation D ta An offset printing press having a blanket cylinder in- [63] continuation of Serv 308341 21, I972 cludes a washing device adjustable with respect to the abandoned blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional driv- 301 Foreign A li ti p i m ing engagement with and traversible relative to the Nov. 24' [971 Germany 2158185 blanket cylinder, means for wetting the washing roller with wash solution, a collecting vessel underlying the 52 us. c1. 101/425; 151256.52; 222/517; washingfmle having a firm surface 222/556 located 1n continuous frictional engagement with the 51 Int. Cl. B411 35/06; B411 41/06 washmg a blade abuting [58] Field of Search U 01/425; 222/517, 556; face of the doctor roller for guiding therefrom into the 15/2565 256-52 collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having [56] Reerences Cited :1 firmnsurface lengagingbthltle soft covering of the washing ro er at a ocation e ind the doctor roller in the UNITED STATES PATENTS rotary direction of the washing roller, the distributor 511,934 1/1894 Cottrell 101/425 toner being wettable with f h wash Solution 951,489 3/1910 Saxton 101/425 2,659.305 11 /1953 Giori 101/423 x 9 Claims, 5 Drawing Figures SHEET PATENTED AUG 5 I975 FIG.

PATENTED AUG 5 I975 SHEET SHEE? PATENTED AUG 5 8975 FIG.

SHEET PATENTED AUB 5 FIG. 4

FIGS

WASHING DEVICE FOR A BLANKET CYLINDER OF AN OFFSET PRINTING PRESS This is a continuation, of application Ser. No. 308,341, filed Nov. 21, 1972, now abandoned.

The invention relates to a washing device adjustable with respect to the blanket cylinder in an offset printing press and, more particularly, to such a washing device which comprises a rotary washing roller having a soft covering and being in frictional driving engagement with and traversible relative to the blanket cylinder, means for wetting the washing roller with wash solution, a collecting vessel underlying the washing roller, a doctor roller having a firm surface located in continuous frictional engagement with the washing roller and a doctor blade abutting the firm surface of the doctor roller for guiding therefrom into the collecting vessel ink washed off the blanket cylinder with the wash solution. Such a washing device is The subject of and has been described in my application Ser. No. 123,946 filed Mar. 15, 1971, now abandoned.

It is an object of the invention to provide a washing device for the blanket cylinder of an offset printing press which will clean the blanket cylinder of any ink thereon in the shortest possible time with the most economical consumption of wash solution.

It is a further object of the invention to provide such a washing device with an improved and relatively simpler control for the supply of wash solution and an optimal distribution of the supplied wash solution With the foregoing and other objects in view, the washing device of the invention is provided with a distributor roller having a firm surface engaging the soft covering of the washing roller at a location behind the doctor roller in the rotary direction of the washing roller, the distributor roller being wettable with fresh wash solution.

The nip or contact gap between the distributor roller and the washing roller effect a completely uniform distribution of the wash solution dripping from the nozzles onto the distributor roller, so that the washing roller is provided over the entire breadth thereof with a film of wash solution. A further advantage of the distributor roller is that it flings any excessively applied wash solution into the collecting vessel. This thereby effectively prevents penetration of wash solution into the channel of the blanket cylinder.

To effect trouble-free control of the supply of wash solution there is provided, in accordance with a further feature of the invention, a drip tube mounted above the distributor roller and extending along substantially the entire length thereof, and sealing means for closing the openings in nozzles extending from the drip tube. The sealing means are formed, for example of small vulca nized rubber plates. They permit exact closure of the nozzle openings when only slightly compressed.

In accordance with an additional feature of the invention the washing device includes a control or shifter rod revolvable about an axis that extends parallel to the drip tube, leaf spring means secured to the shifter rod and having a free end, the sealing means being carried by the leaf spring means at the free end thereof, the shifter rod being adjustable about the axis to two suc' cessive indexing positions wherein the sealing means closes the nozzle openings and to a third indexing position wherein the nozzle openings are kept open.

Although the invention is illustrated and described herein as embodied in washing device for a blanketcylinder of an offset printing press, it is nevertheless not intended to be limited to the details shown since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

FIG. I is a vertical sectional view ofa washing device for a blanket cylinder of an offset printing press according to the invention, wherein the washing devicce is in washing position;

FIG. 2 is another view similar to that of FIG. 1 showing the washing device in dry position;

FIG. 3 is still another view similar to those of FIG. I and 2 showing the washing device in neutral position;

FIG. 4 is a partial longitudinal sectional view of FIGS. 1 to 3 from which several of the parts shown in the plane of the section of FIGS. 1 to 3 have beem omitted in the interest of clarity; and

FIG. 5 is a view of a detail of FIG. 4 as seen from the right-hand side thereof.

Referring now first to FIGS. 1 to 3 and particularly to FIG. 4, there is shown therein a washing roller 2 which is traversibly mounted by two needle bearings 3 in a rocking frame 1. A cam 5 is secured on a shaft 4 of the washing roller 2 and runs against a roller 6 which is rotatably mounted on the rocking frame I. A respective rubber raceway 7 is located on the shaft 4 at each side of the washing roller 2. Both rubber raceways 7, in the operating position of the washing device of the invention as shown in FIG. 4, for example, are in frictional engagement with respective opposing Schmitz rings or cylinder bearers 8 of a blanket cylinder 9 of an offset printing machine. As in generally known, Schmitz rings are located, for example, at the axial ends of the blanket cylinder. Depending upon the compressive load, they are formed of cast iron or hardened steel. For further details regarding the construction and installation of Schmitz rings or cylinder bearers and the operation thereof, reference can be made, for example, to U.S. Pat. No. 3,049,996 of R. H. Downie.

The diameter of the rubber raceways 7 is about 1 mm. greater than that of the soft covering I0 of the washing roller 2.

A doctor roller 14 is mounted by means of ball bearings 15 in the rocking frame 1 parallel to the washing roller 2. The ball bearings 15 are located in guiding grooves I6 and are displaceable in direction toward the washing roller 2. The compressive force between a firm or hard jacket 18 of the doctor roller 14 and the soft cover 10 of the washing roller 2 is adjustable through the displaceable ball bearings 15 and the shaft IS with the aid of non-illustrated adjusting or set screws. Another roller, namely a distributor roller 40, is located above the doctor roller 14. The distributor roller 40, as viewed in rotary direction of the washing roller 2, is located behind the doctor roller 14, and has a firm or hard jacket 51, similarly. The distributor roller 40 is journalled in ball bearings 41 which are mounted so as to be displaceable in guiding grooves by non-illustrated adjusting or set screws. By displacing the ball bearings 41, the firm or hard jacket 51 of the distributor roller 40 is compressible with varying strength against the soft cover 10 of the washing roller 2.

A collecting vessel 19 screens all three aforedescribed rollers 2, I4 and 40 so that stripped-off ink or flung-off wash solution is collected therein. At the deepest location of the collected vessel 19, it is provided with a discharge tube through which the washed-off ink together with used wash solution can flow off into a larger container. Within the collecting vessel 19, there is located a doctor blade 21 which is formed of a leaf spring 23 and a rubber blade or scraper 24. The leaf spring 23 is firmly secured to the inner wall surface of the collecting vessel 19. The rubber scraper or blade 24 abuts the hard or firm jacket I8 of the doctor roller 14 under light pressure. The jacket 18 may be covered with a hard material such as the material known by the trade name Rilsan or can, alternatively have a copper surface layer.

Above the distributor roller 40, a drip tube 26 extends parallel to and along the entire length of the washing roller 2. The drip tube 26 is suitably fastened to the frame 33 of the offset printing press, as by machine screws as shown at the top of FIG. 4. The underside of the drip tube 26 is provided with a plurality of drip nozzles 27 which are disposed in a row, spaced for example 50 mm apart. The drip nozzles 27 may be unscrewed from the drip tube 26, and contain a filter insert 28 of felt or any other suitable permeable material. The permeability of the filter insert 28 determines the flow-through rate of the wash solution present in the drip tube 26. The wash solution 29 is supplied from a non-illustrated container to the drip tube 26 through a feed tube 30.

The nozzle openings 31 of the drip nozzles 27 are closable by seals 45. Each of the seals 45 is vulcanized to the free end of a series of leaf springs 46. Rubber is preferably used as material for the seals 45, although any other suitable material can be used therefor.

The leaf springs 46 are fastened to the rear side of a control or shifter rod 47. They are secured in such a position that the shifter rod 47 can revolve to a relatively great extent without causing too great a compressive force to be applied to the seals 45 as well as without causing too great a horizontal displacement of the seals with respect to the nozzle openings 31. At both ends of the shifter rod 47, there is located a control shaft 49, being firmly secured threadedly to the shifter rod 47. The shifter rod 47 is revolvable or rockable about the rotary axis of the control shaft 49. Directly at the inner surface of both frame walls 33, a rocking cam 35 is provided on the control shaft 49, and controls an adjusting member 34 through a cam follower roller 43. The ad justing member 34 is in the form of a bell crank and carries, at one lever end thereof, the aforedescribed cam roller 43, and at the other lever end thereof, the adjusting or set screw 37, which has an end abutting a stop 42 of the rocking frame I.

The adjusting member 34 is pivotally mounted by a bearing pin 44 in the frame wall 33. The rocking frame 1 is similarly pivotally supported on both sides rotatably on a bearing pin 32 in the frame 33 of the offset printing press. By rocking the adjusting member 34, the rocking frame 1 can be reciprocably swung about the bearing pin 32 through a given angle of rotation so that the soft cover 10 of the washing roller 2 comes into engagement with the rubber cloth of the blanket cylinder 9 or is again disengaged therefrom.

At the operators side of the offset printing press, a control lever 48 is secured at a free end of the control shaft 49 which extends through a casing 53. The control lever 48 is adjustable to three control positions which are indexted by a drop-in pin 55. In FIG. 5, the control lever 48 is shown in lateral view, coordinated 4 with a scale 50 marked with the positions Washing," "Drying" and Off."

The operation of the aforedescribed washing device is as follows:

The blanket cylinder 9 is brought into non-printing position for the purpose of washing the same. Then the control lever 48 is swung into the control position Washing." The adjustment to this setting causes the seals 45 to be swung downwardly away from the nozzle openings 31 as shown in FIG. I. Simultaneously, through the rocking cam 35, the cam roller follower 43, the adjusting member 34 and the set screw 37. the rocker frame I, is rocked counter-clockwise. as viewed in FIG. I, until the soft cover 10 of the washing roller 2 is pressed against the surface of the blanket cylinder 9. While wash solution then drips onto the distributor roller from the nozzle openings 31, the blanket cylinder 9 sets the washing roller 2, the doctor roller 14 and the distributor roller 40 into rotation by mutual frictional contact. The dripping wash solution 29 is transported by the distributor roller 40 in clockwise direction as viewed in FIG. 1, for example, into the gap or nip between the washing roller 2 and the distributor roller 40, a uniform distribution of the existing wash solution being effected over the entire breadth of the soft cover 10 of the washing roller 2. The ink removed from the blanket cylinder 9, based upon the ink-division principle is taken over to the extent of about 50 percent thereof by the doctor roller I4 and is stripped off the latter by the rubber doctor blade 24.

If the rubber cloth covering of the blanket cylinder I is deemed by the operator to be adequately clean, the lever 48 is then swung to the position Drying wherein, as shown in FIG. 2, the seals close the nozzle openings 31, while the three rollers 2, l4 and 40 of the washing device continue to rotate, however. In the position Drying," the washing device effects a rapid drying of the previously wetting rubber cloth 9 of the blanket cylinder 9.

After completion of the drying operation, the control lever 48 is swung into the position Off," wherein the nozzle openings 31 remain closed by the seals 45, as shown in FIG. 3, while the cam roller follower 43 drops into a depression formed in the rocker cam 35 so that, as a result of its own weight, the entire rocker frame 1 rocks clockwise, as shown in FIG. 3, for example, to an extent that is permitted by the adjusting member 34. In this position, the washing device is disposed in a swungaway rest or neutral setting.

As noted hereinbefore, the invention is not limited to the embodiment shown in the drawing. For example, the drip tube 26 can also be located above the washing roller 2. Furthermore, it is possible to mount the seals 45 on other types of control members than that of the illustrated embodiment, such as, for example, on control members which displace the seals 45 in horizontal direction below the nozzles 27. Moreover, the control of the washing device of the invention can also be effected automatically.

I Claim:

1. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional driving engagement with and traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with saidwashing roller, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, a distributor roller havinga firm surface engaging said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller, said distributor roller being wettable with fresh wash solution, a drip tube mounted above said distributor roller and extending along substantially the entire length thereof, said drip tube having a plurality of nozzles formed with nozzle openings, and further including sealing means, said nozzle openings being closable by said sealing means, a shifter rod revolvable about an axis that extends parallel to said drip tube, leaf spring means secured to said shifter rod and having a free end, said sealing means being carried by said leaf spring means at said free end thereof, said shifter rod being adjustable about said axis to two successive indexing positions wherein said sealing means closes said nozzle openings and to a third indexing position wherein said nozzle openings are kept open.

2. Washing device according to claim 1, wherein said washing roller, said doctor roller and said distributor roller are mounted in a rocking frame, and including a respective control cam mounted at each end of said shifter rod, and control means actuable by the control cams for rocking said roller about a given angle.

3. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engagement with the blanket cylinder for driving by the blanket cylinder and being traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with said washing roller for driving by said washing roller, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having a firm surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller, said distributor roller being wettable with fresh wash solution, a drip tube mounted above said distributor roller and extending along substantially the entire length thereof, said drip tube having a plurality of nozzles formed with nozzle openings, and further including sealing means, said nozzle openings being closable by said sealing means.

4. ln an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engage ment with the blanket cylinder for driving by the blanket cylinder and being traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with said washing roller for driving by said washing roller, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having a firm surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller said distributor roller being wettable with fresh wash solution, said wetting means comprises means for dripping the wash solution by gravity onto the washing roller and said dripping means includes a material of predetermined permeability arranged for flow therethrough of the wash solution whereby the rate of the dripping of the wash solution is determined by the permeability of the permeable material.

5. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engagement with the blanket cylinder for driving by the blanket cylinder and being tranversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with said washing roller for driving by said washing roller, a doctor blade abutting said firm surface of said doctor roller for guid ing therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, and a dis tributor roller having a firm surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller, said distributor roller being wettable with fresh wash solution, a drip tube mounted above said distributor roller and extending along substantially the entire length thereof, said drip tube having a plurality of nozzles formed with nozzle openings, and further including sealing means, said nozzle openings being closeable by said sealing means and said wetting means comprises means for dripping the wash solution by gravity onto the distributor roller, and said dripping means includes a material of predetermined permeability arranged for flow therethrough of the wash solution whereby the rate of the dripping of the wash solution is determined by the permeability of the permeable material.

6. ln an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engage ment with the blanket cylinder for driving by the blanket cylinder in the same surface direction at point of contact and being traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said rollers, a doctor roller having a hard surface located in continuous frictional engagement with said washing roller for driving by said washing roller, in the same surface direction at point of contact, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, said means for wetting, comprising a distributor roller having a hard surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller, in the same surface direction at point of contact, said distributor roller being solution to the washing roller.

8. Washing device according to claim 6, wherein said wetting means comprises means for dripping the wash solution by gravity onto the distributor roller.

9. Washing device according to claim 6, including means for supplying the wetting means with wash solution during the washing.

l i t i

Claims

1. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional driving engagement with and traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with said washing roller, a doctor blade abutting said firm surface of said Doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, a distributor roller having a firm surface engaging said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller, said distributor roller being wettable with fresh wash solution, a drip tube mounted above said distributor roller and extending along substantially the entire length thereof, said drip tube having a plurality of nozzles formed with nozzle openings, and further including sealing means, said nozzle openings being closable by said sealing means, a shifter rod revolvable about an axis that extends parallel to said drip tube, leaf spring means secured to said shifter rod and having a free end, said sealing means being carried by said leaf spring means at said free end thereof, said shifter rod being adjustable about said axis to two successive indexing positions wherein said sealing means closes said nozzle openings and to a third indexing position wherein said nozzle openings are kept open.

4. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engagement with the blanket cylinder for driving by the blanket cylinder and being traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with said washing roller for driving by said washing roller, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having a firm surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller, said distributor roller being wettable with fresh wash solution, said wetting means comprises means for dripping the wash solution by gravity onto the washing roller and said dripping means includes a material of predetermined permeability arranged for flow therEthrough of the wash solution whereby the rate of the dripping of the wash solution is determined by the permeability of the permeable material.

5. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engagement with the blanket cylinder for driving by the blanket cylinder and being tranversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said washing roller, a doctor roller having a firm surface located in continuous frictional engagement with said washing roller for driving by said washing roller, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having a firm surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller, said distributor roller being wettable with fresh wash solution, a drip tube mounted above said distributor roller and extending along substantially the entire length thereof, said drip tube having a plurality of nozzles formed with nozzle openings, and further including sealing means, said nozzle openings being closeable by said sealing means and said wetting means comprises means for dripping the wash solution by gravity onto the distributor roller, and said dripping means includes a material of predetermined permeability arranged for flow therethrough of the wash solution whereby the rate of the dripping of the wash solution is determined by the permeability of the permeable material.

6. In an offset printing press having a blanket cylinder, a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional engagement with the blanket cylinder for driving by the blanket cylinder in the same surface direction at point of contact and being traversible relative to the blanket cylinder, means for wetting said washing roller with wash solution, a collecting vessel underlying said rollers, a doctor roller having a hard surface located in continuous frictional engagement with said washing roller for driving by said washing roller, in the same surface direction at point of contact, a doctor blade abutting said firm surface of said doctor roller for guiding therefrom into said collecting vessel ink washed off the blanket cylinder with the wash solution, said means for wetting, comprising a distributor roller having a hard surface in frictional engagement with said soft covering of said washing roller at a location behind said doctor roller in the rotary direction of said washing roller for driving by said washing roller, in the same surface direction at point of contact, said distributor roller being wettable with fresh wash solution, said doctor roller acting to remove dirty material from said washing roller before clean washing solution is deposited on said washing roller by said distributor roller and means to dry said blanket cylinder including means to remove the supply of wash solution.

7. Washing device according to claim 6, wherein said wetting means comprises means for supplying the wash solution to the washing roller.