GB1559783A

GB1559783A - Printing machines

Info

Publication number: GB1559783A
Application number: GB3033075A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-07-19
Filing date: 1976-07-19
Publication date: 1980-01-23

Description

(54) PRINTING MACHINES (71) We, HOWARD JAMES LAN CASTER, of 324 Spring Lane, Mapperley, Nottingham, NG3 5RQ, and TERENCE STUART CARLISLE, of 11 Barratt Lane, Attenborough, Nottingham, both British subjects, 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 printing machines.

According to one aspect of the invention a printing machine comprises means for feeding a web of material to be printed to a printing station and means for delivering printed material from said printing station, the printing station comprising a common impression cylinder and a plurality of printing cylinders, the printing cylinders being independently radially adjustable relative to said common impression cylinder by mounting each of said plurality of printing cylinders on a shaft which is eccentrically mounted on a rotatable member, whereby rotation of the rotatable member causes radial adjustment of the axis of the printing cylinder relative to the axis of the impression cylinder.

Advantageously, printing cylinders are also adjustable relative to the impression cylinder, axially, circumferentially, and/or angularly.

Axial adjustment of the printing cylinder may be obtained, with advantage, by mounting the printing cylinder slidably on a sleeve carrying a driving gear and adjusting the position of the cylinder relative to the sleeve, e.g. by screw thread means.

Circumferential adjustment of the printing cylinder is preferably achieved by using a helical drive gear so that axial movement thereof causes circumferential adjustment relative to the impression cylinder.

It is advantageous that the adjustment means is a self centring arrangement so that when the gear is moved to produce circumferential adjustment then there is no resultant axial movement between the printing cylinder and the impression cylinder.

A suitable self-centring arrangement comprises a rotatable member with two spaced circumferential threads of equal pitch, one being a left hand and the other a right hand thread, and a nut disposed on each thread, one nut being constrained against rotation, whereby rotation of the member relative to one nut causes the constrained nut to move relative to- the member so as to maintain the original spacing between the nuts.

Angular adjustment may be achieved by means of an eccentric device which is rotatable relative to the printing cylinder or a sleeve supporting it so that rotation of the eccentric device will cause radial movement of one end of the printing cylinder whilst the other end is not moved, thus effecting an angular adjustment.

Preferably each printing unit comprises as a modular unit a printing cylinder and associated inking means. Conveniently all the printing units associated with the common impression cylinder are modular units and are provided with similar means for attachment to the machine so that the means are inter-changeable.

In one embodiment of the invention the printing cylinder is a stereo roller and is associated with an ink duct having an "ANILOX" (registered Trade Mark) roller.

This invention is, however, also applicable to other types of printing such as litho; intaglio; letterpress; heliogravure; photogravure; rotoragravure and aniline.

Combinations of such printing techniques can be employed if desired.

A variety of webs can be printed, for example, films of natural or synthetic plastics material, foils, paper webs, and textile webs formed from natural or synthetic fibres. The webs may be adhesive coated and/or be provided with a backing layer. In addition, by variation of web threading in the machine application of adhesives to dual webs and subsequent laminating is possible.

Reference is now made to the accompanying drawings in which: Figure 1 is a diagrammatic front elevation of a printing machine according to the invention; Figure 2 is a side elevation of a radially adjustable support for a printing unit; Figure 3 is an end elevation of the support shown in Figure 2; Figure 4 is a cross-section of a stereo cylinder and adjustment means shown in position on a support as shown in Figures 2 and 3; Figure 5 is a cross-section of part of an ink duct for use in printing unit according to the invention; Figure 6 is a cross-section of a nip roller for use in the machine according to the invention; Figure 7 is a cross-section of a slitter for use on a machine according to the invention; and Figure 8 is a cross-section of a die-cutting device for use on a machine according to the invention.

Referring to Figure 1 the printing machine is an open-sided machine comprising a support frame 10, the drive means (e.g. a chain and sprockets arrangement) being disposed on the side of the support frame oppposite to that shown in Figure 1.

A common impression cylinder 11 is mounted for rotation in the direction of arrow A and has arranged around its periphery for example, four printing units 12 and a nip roller assembly 13. Two spindles for web rolls 14 and 15 are provided. A web 16 may be led from either or both of these rolls via adjustable guides to the nip roller 13 around the common impression cylinder 11 to a feed roller 17, a feed roller 18 and a pair of friction driven take-up spindles 19 and 20.

If desired, drying means (not shown) such as a heated box may be included between feed roller 17 and feed roller 18. The heating means may be, for example, infra red or a contact heater plate; ultra violet heaters may be arranged to "flash dry" appropriate printing inks.

The spindles 14 and 15 are each provided with automatic cut-off means comprising a bar follower detector which is gravitybiassed onto the web-roll which actuates a microswitch when the web-roll is a predetermined minimum size thus causing the power to the machine to be interrupted and, if desired, also operating a visual and/or audible alarm.

The provision of two spindles for web rolls and two take-up spindles increases the versatility of the machine. For example, the machine may be used to print two webs sideby-side or even if the machine is used for single web printing then the second spindle enables the machine to be set up whilst printing is taking place thereby decreasing the "down-time" due to the web-roll changing.

If desired an additional printing means 12a may be included, for example for printing the reverse side of the web. In addition, if desired, one or more slitting stations 21b and a punching device 21a may be provided.

The printing units shown in Figures 4 and 5 of the drawings are each flexographic means including a stereo printing cylinder 36 and an ink duct 23. Alternative printing means may, of course be employed and if necessary the surface of the common impression cylinder may be modified in order to suit the nature of the printing cylinder employed.

Each printing unit support 24 comprises a cylindrical plate 25 bolted to the frame 10 by bolts 26. A shaft carrier 27 is rotatably mounted on the plate 25 and carries a shaft 28 which has a reduced diameter end portion 28a. The outer cylindrical surface of the shaft carrier 27 is provided with a toothed rack 29 over et least a portion of said surface. The rack 29 is engaged with worm 30 rotatable by control knob 31 to adjust the position of she shaft 28 relative to the axis 34 of the shaf carrier 27. A brake restrictor is also provided to counteract backlash and includes a threaded shank 35, control knob 32 and a friction block 33 of resilient material.

The printing cylinder 36 is mounted on a printing cylinder sleeve 37 which, in turn, is located on shaft 28. The sleeve 37 carries a rigid wheel 49 having helical gear teeth 50 which engage with a helical gear associated with the impression cylinder 11. A rotatable threaded sleeve 38 is located on the reduced diameter portion 28a of the shaft 28, the sleeve being provided with two threaded portions, a right-hand thread 39 and a lefthand thread 40.

Threaded on the right-hand thread 39 is a keyed nut 41 having keys 42 which are slidably received in keyways in the printing cylinder sleeve 37 to permit relative axial movement but prevent relative rotation. A bearing 43 is also provided.

Threaded on the left-hand thread 40 is an adjusting nut 44 and a lock nut 44a, whilst the rotatable threaded sleeve 38 has a knurled adjusting flange 45 rigid therewith and an associated lock-nut 46.

The sleeve 38 has an eccentric inner sleeve 38a disposed between it and the reduced diameter portion 28a of the shaft 28. A cap screw 47 received in a threaded bore in the shaft portion 28a normally holds the eccentric sleeve in fixed relationship to the shaft portion 28a but when this is relaxed the eccentric sleeve can be rotated (by means of a saw gate 48).

A printing cylinder 36 is located on the shaft 28 and adjusted in the following manner.

Adjustment of the position of the printing cylinder 36 radially relative to the impression cylinder is effected by control knob 31 which causes the carrier 27 to rotate and thus change the position of shaft 28.

Axial adjustment of the position of the printing cylinder 36 is effected by moving the printing cylinder 36 axially relative to the printing cylinder sleeve 37. This is achieved by rotating adjusting nut 44 which by virtue of its threaded engagement with the sleeve 38 moves to the left as seen in Figure 4, and captive friction pads 51 and flanged bush 52 cause the cylinder 36 also to move to the left.

Adjustment of the printing cylinder 36 circumferentially relative to the impression cylinder is achieved by rotating the knurled adjusting flange 45 whilst restraining the adjusting nut 44. This causes the printing cylinder sleeve 37 to move axially relative to the shaft 28 and helical gear teeth 50 also move axially relative to the helical gear associated with the common impression cylinder. By virtue of the helical nature of the gear teeth this also rotates the gear wheel 49 (and hence printing cylinder 36) relative to the common impression cylinder.

Axial movement of the printing cylinder 36 is avoided however by virtue of the self-centering nature of the adjusting means.

Thus as the sleeve 37 is moved to the left as seen in Figure 4 by rotation of sleeve 38, the nut 41 moves to the right relative to sleeve 38 by an equal amount, since it is located on a left hand thread and cannot rotate relative to sleeve 37. This compensating movement to the right thus ensures that the printing cylinder 36 does not move axially relative to the common impression cylinder. When the necessary adjustments have been made lock nut 46 is tightened to maintain the adjustments.

One other adjustment is possible, i.e. an angular adjustment of the axis of the printing cylinder relative to that of the common impression cylinder. This adjustment is made possible by the provision of the eccentric sleeve 38a, rotation of which can move one end of the printing cylinder sleeve 37 radially relative to the shaft portion 28a. The other end remains relatively stationary radially so that the desired angular adjustment can be made.

The sleeve is held in its adjusted position by means of cap screw 47 as described above.

One form of ink duct for use in a flexographic process is illustrated in Figure 5. It will be appreciated that other configurations and combinations of sleeves and/or rollers can be accommodated to facilitate other methods of printing if desired.

Referring to Figure 5 the ink duct 23 comprises an ink reservoir 53 and an "ANILOX" (registered Trade Mark) roller 54. The ANILOX roller 54 is rotatably mounted on a sleeve 55 which is arranged to be received on a shaft 56 which extends from a rotatable support 57 on the frame 10 of the machine. The support 57 is rotated by means of a worm device (not shown) similar to that shown in Figure 3.

Thus the ink duct 23 can be brought into working relationship with the printing cylinder 36 by rotation of the support 57.

Adjustment of the angular relationship between the printing cylinder 36 and ANILOX roller 54 is achieved by means of the adjusting nut 58 which has an eccentric integral bush 59 which locates the inner surface of the sleeve 55. The adjusting nut 58 may be locked in position by means of the lock nut 60.

The ink reservoir is basically of conventional design, having adjusting screws 61 for adjusting the ink supply to the roller 55 and being carried by the two end plates 62. In order to enable the angle of the ink reservoir 53 to be adjusted relative to the ANILOX roller 54 a series of radially distributed apertures (not shown) are provided in the end plate 62 adjacent the support 57. A pin (not shown) is provided in the support 57 so that the ink reservoir 53 may be pivoted about the axis of the anilox roller 54 to one of a number of predetermined positions by locating the pin in one of the radially distributed apertures.

The nip roller assembly 13 is shown in more detail in Figure 6. The position of the roller may be adjusted relative to the common impression cylinder 11 (Figure 1) by the rotatable support 63 which is similar to the support 57 shown in Figure 5. The nip roller 64 is carried by an arm 65 which is mounted on a pair of spring loaded plungers 66 whereby resilient pressure is applied to the nip roller 64.

The nip roller assembly 13 also carries a pair of guides 67 for guiding a web to be printed, the guides 67 being secured to a transverse rod 68, the lateral position of which can be adjusted by means of adjusting knob 69. The guide spacing can be adjusted by moving one or both guides 67 relative to the rod 68 and to this end may be secured thereto by means of set screws (not shown).

One form of slitter is shown in Figure 7.

The slitter 70 is designed to fit on to a shaft 71 on the frame 10 of the machine. The slitter 70 comprises a pair of parallel rotatable shafts 72 and 73 journalled in a slitter frame 74 and geared so as to rotate together, the drive being derived from the shaft 72 and transmitted via gears 77 and 78.

An adjusting screw 75 (similar to the worm 30 shown in Figures 2 and 3) is in engagement with a peripheral thread 76 (only a portion of which is shown schematically) to facilitate adjustment of the relative spacing of shafts 72 and 73.

The shaft 73 carries a plurality of slitting blades 79 which can be fixed in any desired axial position along the shaft 73 by means not shown. Each slitting blade 79 has a complementary blade 80 which can be fixed in position on shaft 72 by means not shown.

It will be appreciated that when the slitter is used on the machine the number and the positions of the slitting blades can be adjusted to give the desired product.

Rotation of the adjusting screw 75 enables the slitting blades readily and simply to be moved into and out of slitting engagement.

One form of die-cutting device is shown in Figure 8. The device is attached to a shaft on the frame 10 and comprises a die-cutting device frame 81 which supports a pair of cooperating die-cutting rollers 82 and 83. The end of the roller 83 has a trunnion 84 received in a bearing 85 and adjustment is achieved by means of the adjusting knob 86.

The printing machine of the invention has many advantages over conventional machines. One of these is that each printing means may be produced as a modular unit which units are inter-changeable. The support means affords a considerable amount of adjustment radially relative to the common impression cylinder so that a wide range of printing cylinder diameters can be accommodated.

The open sided nature of the machine enables the printing means to be changed easily and the adjustment means, enable quick and precise adjustment to be made, if desired whilst the machine is actually printing.

A printing machine incorporating a self-centring device to maintain the relative axial positions of the printing cylinder and the impression cylinder when a circumferential adjustment is carried out is claimed in our copending application no. 749/79 (Serial No. 1,559,784) which is divided from this application.

WHAT WE CLAIM IS: 1. A printing machine comprising means for feeding a web of material to be printed to a printing station and means for delivering printed material from said printing station, the printing station comprising a common impression cylinder and a plurality of printing cylinders, the printing cylinders being independently raidally adjustable relative to said common impression cylinder by mounting each of said plurality of printing cylinders on a shaft which is eccentrically mounted on a rotatable member, whereby rotation of the rotatable member causes radial adjustment of the axis of the printing cylinder relative to the axis of the impression cylinder.

2. A printing machine according to claim 1 in which the printing cylinders are angularly adjustable relative to the impression cylinder.

3. A printing machine according to claim 1 or 2 in which the printing cylinders are axially adjustable relative to the impression cylinder.

4. A printing machine according to any of claims 1 to 3 in which the printing cylinders are circumferentially adjustable with respect to the impression cylinder.

5. A printing machine according to claims 3 or 4 in which the printing cylinder is mounted slidably on a sleeve carrying a driving gear and the position of the printing cylinder is adjustable relative to the sleeve whereby axial adjustment of the printing cylinder relative to the impression cylinder may be produced.

6. A printing machine according to claims 4 or S in which circu.r.ferential adjustment of the printing cy]L7lder relative to the impression cylinder i; provided by using a helical drive gear for the printing cylinder so that adjustment of the drive gear in an axial direction causes circumferential adjustment of the printing cylinder relative to the impression cylinder.

7. A printing machine according to any of claims 2 to 6 in which the printing cylinder is mounted on an eccentric device rotatable relative to said printing cylinder or a sleeve supporting it so that rotation of the eccentric device causes radial movement of one end of the printing cylinder relative to the other end thereof, thus effecting angular adjustment of the printing cylinder relative to the impression cylinder.

8. A printing machine according to any of claims 1 to 7 in which the printing cylinder and associated inking means are assembled as a modular printing unit.

9. A printing machine according to claim 8 in which the printing cylinder is a stereo roller and is associated with an ink duct.

10. A printing machine according to any of claims 1 to 9 provided with an additional printing unit which is not associated with the common impression cylinder.

11. A printing machine according to one of claims 1 to 10 provided with a heating device.

12. A printing machine according to any of claims 1 to 11 provided with a slitter.

13. A printing machine according to any

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. slitter 70 comprises a pair of parallel rotatable shafts 72 and 73 journalled in a slitter frame 74 and geared so as to rotate together, the drive being derived from the shaft 72 and transmitted via gears 77 and 78. An adjusting screw 75 (similar to the worm 30 shown in Figures 2 and 3) is in engagement with a peripheral thread 76 (only a portion of which is shown schematically) to facilitate adjustment of the relative spacing of shafts 72 and 73. The shaft 73 carries a plurality of slitting blades 79 which can be fixed in any desired axial position along the shaft 73 by means not shown. Each slitting blade 79 has a complementary blade 80 which can be fixed in position on shaft 72 by means not shown. It will be appreciated that when the slitter is used on the machine the number and the positions of the slitting blades can be adjusted to give the desired product. Rotation of the adjusting screw 75 enables the slitting blades readily and simply to be moved into and out of slitting engagement. One form of die-cutting device is shown in Figure 8. The device is attached to a shaft on the frame 10 and comprises a die-cutting device frame 81 which supports a pair of cooperating die-cutting rollers 82 and 83. The end of the roller 83 has a trunnion 84 received in a bearing 85 and adjustment is achieved by means of the adjusting knob 86. The printing machine of the invention has many advantages over conventional machines. One of these is that each printing means may be produced as a modular unit which units are inter-changeable. The support means affords a considerable amount of adjustment radially relative to the common impression cylinder so that a wide range of printing cylinder diameters can be accommodated. The open sided nature of the machine enables the printing means to be changed easily and the adjustment means, enable quick and precise adjustment to be made, if desired whilst the machine is actually printing. A printing machine incorporating a self-centring device to maintain the relative axial positions of the printing cylinder and the impression cylinder when a circumferential adjustment is carried out is claimed in our copending application no. 749/79 (Serial No. 1,559,784) which is divided from this application. WHAT WE CLAIM IS:

1. A printing machine comprising means for feeding a web of material to be printed to a printing station and means for delivering printed material from said printing station, the printing station comprising a common impression cylinder and a plurality of printing cylinders, the printing cylinders being independently raidally adjustable relative to said common impression cylinder by mounting each of said plurality of printing cylinders on a shaft which is eccentrically mounted on a rotatable member, whereby rotation of the rotatable member causes radial adjustment of the axis of the printing cylinder relative to the axis of the impression cylinder.

13. A printing machine according to any

of claims 1 to 12 provided with a die-cutting device.

14. A printing machine according to any of claims 1 to 13 in which the printing units are mounted on an open side of a frame of the machine.

15. A printing machine according to claim 14 comprising a frame having on one side thereof a plurality of driven spindles for receiving printing units and/or a slitter and/or a die-cutting device and on the other side thereof drive means for said spindles.

16. A printing machine substantially as herein described with reference to and as shown in the accompanying drawings.