GB1573691A

GB1573691A - Transfer rollers

Info

Publication number: GB1573691A
Application number: GB4179/78A
Authority: GB
Original assignee: Baker Perkins Holdings Ltd
Current assignee: Baker Perkins Holdings Ltd
Priority date: 1978-02-02
Filing date: 1978-02-02
Publication date: 1980-08-28
Also published as: DE2903409C2; FR2416377B1; JPS56173449U; FR2416377A1; JPS54114310A; DE2903409A1

Description

(54) IMPROVEMENTS IN OR RELATING TO TRANSFER ROLLERS (71) We, BAKER PERKINS HOLD INGS LIMITED of Westfield Road, Peterborough, Cambridgeshire PE3 6TA, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to transfer rollers, and is concerned with rollers for transferring liquids, such as printing ink, from one rotating surface to another. Such a transfer roller may be hereinafter referred to as "herein defined".

As used herein, the term "liquid" is intended to include semi-liquids and pastes.

Transfer rollers are used in printing presses, inter alia, to transfer printing ink from a supply (or fountain) roll to one of a train of rolls terminating in a printing plate cylinder.

As it is usual for the two rolls with which the transfer roller cooperates to rotate at different peripheral speeds, the transfer rollers are disposed on a common shaft and are mounted so as to rotate eccentrically thereon, in an out-of-phase manner. This arrangement not only reduces the effect of rapid acceleration and deceleration, (caused by the different peripheral speeds of the rolls); it also produces an undulating motion which results in a continuous transfer of ink spread over a large surface.

British Patent Specification No. 908692, (Carl Allers Establishment A/S), discloses a transfer roller arrangement wherein the rollers are mounted, in an eccentric manner, on a common drive shaft of hexagonal crosssection. The transfer rollers have correspondingly-shaped bores and the desired out-of-phase relationship is achieved by removing one or more transfer rollers from the drive shaft, turning them through 60 (or multiples thereof) and replacing them on the shaft.

This transfer roller arrangement has been successful for many years but demands a high standard of manufacture. Otherwise, incorrect fit of the transfer rollers on their drive shaft can result in incorrect engagement of the rollers with the supply and impression rolls and thus lead to non-continuous and uneven transfer of ink.

According to the present invention, a transfer roller as herein defined, is provided with means for mounting the roller on a drive shaft of substantially circular cross-section so as to be rotated eccentrically thereby, and further provided with coupling means for connecting the roller with a second roller of similar form, so that, when mounted on the drive shaft, the two rollers rotate with an out-of-phase relationship.

The coupling means preferably interlock adjacent side faces of the two rollers, and preferably comprise a dowel on one side face of the roller and at least one dowel-receiving socket on the other side face thereof.

The invention also comprises an assembly formed by a plurality of such transfer rollers, mounted on a drive shaft; the combination of this assembly and a pair of rolls with which the assembly can cooperate, and a printing machine provided with the combination.

Means may be provided for lifting the drive shaft and transfer roller assembly clear of the rolls. This enables ready access to the rolls, for example, for cleaning purposes.

Use of a transfer roller according to the invention avoids the manufacturing and operating difficulties experienced with the known form of transfer roller, referred to above.

An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawings, wherein: Figures 1 and 2 combine to provide a side view, in medial section, of a transfer roller assembly, Figures 3 and 4 are sections, to an enlarged scale, taken on the lines III - II1 of Figure 1 and IV - IV of Figure 2 respectively, Figure 5 is a view looking in the direction of the arrow V of Figure 4, Figures 6 and 7 are, respectively, side and end views of a transfer roller bearing collar, Figure 8 is a view looking in the direction of the arrow VIII of Figure 5, and Figure 9 is a diagrammatic view, in perspective, which illustrates how the transfer roller assembly transfers ink to its cooperating output roll.

In the figures, like reference numerals refer to like components.

Figure 8 shows a transfer roller assembly 1 for transferring printing ink from a supply or fountain roll 2 to a copper-plated roll 3. Roll 3 is the first of a train of rolls terminating in a printing plate cylinder (not shown). The rolls 2, 3 rotate about substantially parallel axes 8 and 9 respectively. As explained hereinafter, the peripheral speed of roll 3 is greater than that of roll 2.

The combination of transfer roller assembly 1 and rolls 2, 3 with which the assembly cooperates forms part of a Baker Perkins "GEMINI" (Trade Mark) web-offset printing machine, (only a small part of which is illustrated herein), manufactured by Baker Perkins Limited, Peterborough, England.

The transfer roller assembly 1 comprises a plurality (thirteen) of contiguously-disposed transfer rollers 4. (See Figures 1, 2 and 9).

The rollers 4, which are of similar form, are mounted side by side on a drive shaft 5 of substantially circular cross-section, so as to be rotated eccentrically thereby (by means described hereinafter). The rollers 4 are further provided with coupling means, comprising laterally-extendin dowels 6 and dowel-receiving sockets 7 Figure 6) for connecting one roller 4 with a second roller 4.

The dowel 6 and socket 7 of each roller 4 are angularly spaced from each other, so that when the two rollers are mounted on the drive shaft 5, they rotate with an out-ofphase relationship.

With additional reference to Figures 6 and 7, the means for mounting a transfer roller 4 on the drive shaft 5 so that it is rotated eccentrically thereby, comprise a bearing collar 10 with an eccentric bore 11 for locating the drive shaft 5. A bearing ring 12 is mounted on the collar 10 and is spaced therefrom by roller bearings 13 held in place by "C" clips 14, 15. A rubber ring or "tyre" 16 is mounted on the outer periphery of the bearing ring 12. The roller bearings 13 allow the rubber ring 16 to rotate relative to the collar 10.

A dowel-receiving socket 7 is formed at each end of the bearing collar 10. As illustrated by Figure 7, the sockets 7 are not in coaxial alignment, but are spaced from each other by 60".

Reverting to Figures 1 and 2, the transfer rollers 4 are held in place on the drive shaft 5 by tubular spacers 1 7a, 1 7b, 1 7c, and clamping bolt/washer assemblies 18/19. The ends of the drive shaft 5 are located by bearing assemblies 20. Each bearing assembly 20 comprises a block 21 locating an annular body 22 which houses a roller bearing 23.

The outer periphery of the body 22, which can rotate within the block, is eccentric with respect to the bore of the body. The body 22 is formed with a ring of radially-extending holes 24 which serve as sockets for a lever or tommy bar 25. Rotation of the body 22 within the block 21 is prevented by a pinch screw 26 located by the block.

Spacer 17c has a socket 7e for receiving a dowel 6 shared with adjacent roller 4, and is secured to shaft 5 by an axially-extending key 31 so as to rotate with the shaft.

The block 21 of Figure 1, (and hence the body 22 thereof), is supported by a bracket 27 bolted to one of a pair of side frames 28 forming part of the printing machine. As best shown in Figure 3, the block 21 is secured to the bracket 27 by a clamping plate 29 held in place by bolts 30 which pass through the block 21. Similarly, the block 21 of Figure 2, (and Figures 4 and 5), is supported by a bracket 27 bolted to the other side frame 28.

The block 21 is secured to its support bracket 27 by a clamping plate 29 held in place by bolts 30. oAdditionally however, the block 21 of Figure 2 locates a driven coupling member 35 mounted on the drive shaft 5 so as to rotate therewith. The driven coupling member 35 has an external flanged portion which carries an axially-extending roller 36 mounted for rotation relative to the member 35. The driven coupling member 35 cooperates with a driving coupling member 37 which also has a flanged portion. However, the flanged portion of the driving member 37 is formed with a diametral slot 38 which locates the roller 36 of the driven member 35 whereby rotation of the member 37 results in corresponding rotation of the member 35.

The roller/slot form of drive accommodates any misalignment errors between the coupling members 35, 37.

The coupling member 37 is mounted on a shaft 39 so as to rotate therewith. The shaft 39 is disposed within the adjacent side frame 28 where it is supported by a roller bearing 40.

The coupled shafts 5 and 39 are rotated by a variable-speed motor 45 (Figure 4) by way of a gear unit 46. The gear unit 46, which is clamped to the side frame 28, supports the motor 45.

With reference now to Figure 8, the transfer roller assembly 1 is disposed between the rolls 2, 3, so as to be able to rest in the "V" formed by adjacent peripheral parts of the rolls. By temporary release of pinch screws 26, by inserting tommy bars 25 in holes 24 of bearing bodies 22 and by applying leverage force to the bars 25, the roller assembly 1 can be moved, (because of the eccentric mounting of the drive shaft ends), along a part circular path, towards and away from the rolls 2, 3. This movement is limited by contact between stop members 50, carried by bearing bodies 22, and stop pins 51, carried by blocks 21. Thereafter, pinch screws 26 are re-tightened.

In operation, the thirteen transfer rollers 4 are disposed on the drive shaft 5 so that, by means of dowels 6 and cooperating sockets 7, interlocking pairs of rollers 4 are spaced from each other in an angular sense. Preferably the disposition is such that one contiguous pair of rollers 4 is in contact with roll 2 at the same time that another contiguous pair is in contact with roll 3, even though each roller of a pair is 60 out of phase with the other of the pair. This arrangement avoids undue loading on the various components due to out-ofbalance forces. The bearing collars 10 of the interlocking rollers 4 are rotated by shaft 5 via spacer 1 7c and the dowel 6 extending between socket 7c of the spacer and socket 7 of adjacent end roller 4.

Fountain or supply roll 2 is rotated in an ink bath (not shown). Rolls 2 and 3 are driven by gear reduction drives. Roll 2 is driven at a speed which permits ink to be removed from the ink duct. (Too fast a rotation could cause roll 2 to "slip" through the ink). The bearing collars 10 of the transfer rollers 4 are rotated (by gear unit 46 through shaft 5) at the same rotational speed as roll 2. The provision of bearings 13 allows the rubber rings 16 of the rollers 4 to be accelerated to the speed of roll 3, which roll rotates at the peripheral speed of the printing plate cylinder, and which is greater than that of roll 2.

When the rubber rings 16 of the transfer rollers 4 are brought into contact with the rolls 2, 3, ink is transferred from roll 2 to roll 3 by the freely rotating rings 16, as schematically illustrated by Figure 9.

The form of roller 4 allows ease of manufacture at greater accuracy compared with known forms of transfer rollers. In addition, use of the rollers 4 avoids operating difficulties experienced with the prior rollers.

Preferably, for pressure contact setting purposes. the rubber rings 16 of the rollers 4 are not forced into contact with rolls 2 and 3.

Instead, they merely rest on the rolls, under the influence of gravity, and are secured in that position.

To obtain access, for example, to allow roll cleaning, the pinch screws 26 are first eased.

Tommy bars 25 are then inserted in holes 24 of bearing bodies 22 and the transfer roller assembly moved away, along a part-circular path, to assume the position shown by Figure 8. Thereafter, pinch screws 26 are retightened.

If required, pairs of rollers 4 may be interlocked with each other so that alternate pairs of rollers 4 rotate in-phase, with intermediate pairs arranged to rotate out-of-phase.

This arrangement results in transfer of larger areas of ink. The same effect can, however, be obtained by using transfer rollers of enlarged width.

The transfer roller coupling means need not comprise the dowels 6 and sockets 7.

Instead, a roller 4 could be provided with a ring of laterally-projecting teeth on each of its side faces, whereby the teeth of adjacent rollers interlock with each other.

WHAT WE CLAIM IS: 1. A transfer roller as herein defined, provided with means for mounting the roller on a drive shaft of substantially circular cross-section, so as to be rotated eccentrically thereby, and further provided with coupling means for connecting the roller with a second roller of similar form, so that when mounted on the drive shaft, the two rollers rotate with an out-of-phase relationship.

2. A transfer roller as claimed in Claim 1, wherein the coupling means are constructed so as to interlock a side face of the roller with the adjacent side face of the second roller.

3. A transfer roller as claimed in Claim 2, wherein the coupling means comprise at least one lateral projection on one side face of the roller and at least one projection-receiving recess on the other side face thereof.

4. A transfer roller as claimed in Claim 3, wherein the coupling means comprise a dowel on one side face of the roller and at least one dowel-receiving socket on the other side face thereof.

5. A transfer roller as claimed in Claim 3, wherein the coupling means comprise rings of laterally-projecting teeth on both side faces of the roller.

6. A transfer roller assembly comprising a plurality of interlocking transfer rollers, each as claimed in any one of Claims 1 to 5, mounted side by side on a drive shaft.

7. The combination of Claim 6 and a pair of rolls with which the transfer roller assembly can cooperate.

8. A printing machine provided with the combination claimed in Claim 7.

9. A printing machine as claimed in Claim 8, provided with actuating means whereby the transfer roller assembly can be moved into or out of contact with said rolls.

10. A printing machine as claimed in Claim 9, wherein the actuating means comprise means for eccentric mounting of the ends of the drive shaft, whereby the drive shaft can be moved along a part-circular path towards and away from said rolls.

11.A transfer roller, substantially as hereinbefore described, with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. 26, by inserting tommy bars 25 in holes 24 of bearing bodies 22 and by applying leverage force to the bars 25, the roller assembly 1 can be moved, (because of the eccentric mounting of the drive shaft ends), along a part circular path, towards and away from the rolls 2, 3. This movement is limited by contact between stop members 50, carried by bearing bodies 22, and stop pins 51, carried by blocks 21. Thereafter, pinch screws 26 are re-tightened. In operation, the thirteen transfer rollers 4 are disposed on the drive shaft 5 so that, by means of dowels 6 and cooperating sockets 7, interlocking pairs of rollers 4 are spaced from each other in an angular sense. Preferably the disposition is such that one contiguous pair of rollers 4 is in contact with roll 2 at the same time that another contiguous pair is in contact with roll 3, even though each roller of a pair is 60 out of phase with the other of the pair. This arrangement avoids undue loading on the various components due to out-ofbalance forces. The bearing collars 10 of the interlocking rollers 4 are rotated by shaft 5 via spacer 1 7c and the dowel 6 extending between socket 7c of the spacer and socket 7 of adjacent end roller 4. Fountain or supply roll 2 is rotated in an ink bath (not shown). Rolls 2 and 3 are driven by gear reduction drives. Roll 2 is driven at a speed which permits ink to be removed from the ink duct. (Too fast a rotation could cause roll 2 to "slip" through the ink). The bearing collars 10 of the transfer rollers 4 are rotated (by gear unit 46 through shaft 5) at the same rotational speed as roll 2. The provision of bearings 13 allows the rubber rings 16 of the rollers 4 to be accelerated to the speed of roll 3, which roll rotates at the peripheral speed of the printing plate cylinder, and which is greater than that of roll 2. When the rubber rings 16 of the transfer rollers 4 are brought into contact with the rolls 2, 3, ink is transferred from roll 2 to roll 3 by the freely rotating rings 16, as schematically illustrated by Figure 9. The form of roller 4 allows ease of manufacture at greater accuracy compared with known forms of transfer rollers. In addition, use of the rollers 4 avoids operating difficulties experienced with the prior rollers. Preferably, for pressure contact setting purposes. the rubber rings 16 of the rollers 4 are not forced into contact with rolls 2 and 3. Instead, they merely rest on the rolls, under the influence of gravity, and are secured in that position. To obtain access, for example, to allow roll cleaning, the pinch screws 26 are first eased. Tommy bars 25 are then inserted in holes 24 of bearing bodies 22 and the transfer roller assembly moved away, along a part-circular path, to assume the position shown by Figure 8. Thereafter, pinch screws 26 are retightened. If required, pairs of rollers 4 may be interlocked with each other so that alternate pairs of rollers 4 rotate in-phase, with intermediate pairs arranged to rotate out-of-phase. This arrangement results in transfer of larger areas of ink. The same effect can, however, be obtained by using transfer rollers of enlarged width. The transfer roller coupling means need not comprise the dowels 6 and sockets 7. Instead, a roller 4 could be provided with a ring of laterally-projecting teeth on each of its side faces, whereby the teeth of adjacent rollers interlock with each other. WHAT WE CLAIM IS:

1. A transfer roller as herein defined, provided with means for mounting the roller on a drive shaft of substantially circular cross-section, so as to be rotated eccentrically thereby, and further provided with coupling means for connecting the roller with a second roller of similar form, so that when mounted on the drive shaft, the two rollers rotate with an out-of-phase relationship.

8. A printing machine provided with the combination claimed in Claim 7.

12. Atransfer roller assembly, substan

tially as hereinbefore described with reference to the accompanying drawings.

13. A combination of a transfer roller assembly and a pair of rolls with which the transfer roller assembly cooperates, substan tially as hereinbefore described with refer ence to the accompanying drawings.

14. A printing machine provided with the combination of Claim 13.