GB2059350A

GB2059350A - Inking system for a printing machine

Info

Publication number: GB2059350A
Application number: GB8030568A
Authority: GB
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1979-09-22
Filing date: 1980-09-22
Publication date: 1981-04-23
Also published as: DE7927000U1; IT8036013V0; CH647717A5; FR2465593A3; GB2059350B; FR2465593B3

Abstract

An inking system for a printing machine comprises colour zone adjusting screws 18 distributed across the width of an ink knife. A respective electric motor 6 is operable to adjust each screw 18, via a reducer 5. A respective rotary knob 23 is also provided for manual adjustment of each screw 18. To prevent damage to the motor 6 and/or reducer 5 by overdriving during manual adjustment, a torque- limiting coupling is provided between the reducer 5 and knob 23. <IMAGE>

Description

SPECIFICATION Inking system for a printing machine This invention relates to inking systems for printing machines.

German Gebrauchmuster 77 30 668 discloses a device for adjusting an ink knife which co-operates with a roller, of an inking system of a printing machine, with several colour zone adjusting screws distributed over the width of the ink knife, in which each colour zone adjusting screw is selectively adjustable either by means of an electric motor with a subsequently added reducer, or manually by means of a rotary knob. In this, the output shaft of the reducer is connected positively via pinions to the colour zone adjusting screw on which the rotary knob is also positively mounted. It has been shown that when the rotary knob is turned quickly by hand, such great forces come about in the reducer, that parts of the reducer can break.

The present invention aims to provide a generally improved system.

According to the peresent invention, there is provided an inking system for a printing machine, the system comprising an ink knife, adjusting means for adjusting the position of the knife, a motor for actuating said adjusting means, manually operable means for actuating said adjusting means, and a torque-limiting coupling between the motor and said manually operable means.

In use of the invention, the coupling preferably reacts in the case of too quick a turning movement on the rotary knob, so that overloading of the motor is avoided.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, the single figure of which shows a part-section through a device accord ing to the invention.

The device comprises a support plate 1, on which a plate 4 is secured by means of screws 2 and spacers 3. The plate 4 carries a reducer 5 and an electric motor 6. Projecting through a recess 7 of the plate is a pivot pin 8, on which a shaft casing is positively mounted by means of a grub screw 9. The pivot pin 8 and the shaft casing 10 together form the output shaft of the reducer 5. A freely rotatable pinion 12 is mounted on to a bearing surface 11 of the shaft casing 10. The pinion 12 forms one part of a torque-limiting coupling. The other part of the coupling is a flange 16 on the shaft casing 10. To achieve the necessary counter pressure a counter pressure spring 15 is provided, which is designed as a plate spring.The counter pressure spring 15 is mounted on a support 14 and holds the pinion 12 in a position of frictional contact with the flange 16. The use of a plate spring has the advantage of taking up little space. In principle, however, other springs, e.g.

a coil spring, can also be used. The support 14 is designed as a nut, which is screwed on to a thread 13 of the shaft casing. As a result of this arrangement the counter pressure of the spring can be applied and adjusted.

The pinion 12 meshes with a further pinion 17, which is prevented from twisting, and mounted on a colour zone adjusting screw 18 in such a way that it is axially immovable. One end of the colour zone adjusting screw 18 is freely rotatable and adjustable in a bore of the support plate 1; the other end of the colour zone adjusting screw 18 cooperates with the ink knife, directly or via intermediary members, in a way which is known in itself and is not shown in any greater detail. The colour zone adjusting screw 18 also carries an external thread 19, which engages in the inner thread of a bearing 20 secured on the plate 4.

In the support plate 1 there is also positioned a shaft 21, one end of which is firmly connected to a pinion 22. The pinion 22 also meshes with the pinion 12. The other end of the shaft 21 carries a rotary knob 23.

If the output shaft 8, 10 of the reducer 5 is rotated to adjust the colour zone adjusting screw 18, the pinion 12 follows this movement as a result of its friction-contact position on the flange 16. As a result of this, the pinion 17 also rotates with the colour zone adjusting screw 18. Due to the engagement of the external thread 19 in the fixed bearing 20, an axial movement of the colour zone adjusting screw 18 is achieved. During this movement, the shaft 21 turns freely with the rotary knob 23.

If the colour zone adjusting screw 18 is to be operated manually, the rotary knob 23 and therefore the shaft 21 are rotated. This rotation is transferred via the pinion 12 on to the pinion 17 of the colour zone adjusting screw, which, as a result, also undergoes an additional axial movement. If the rotation speed of the rotary knob exceeds a certain amount, then the torque-limiting coupling 12, 16 reacts and the pinion 12 slips with respect to the flange 16, so that no more rotation can be transferred to the output shafts 8, 10.

The invention can also be used in an arrangement according to DE-GM 77 30 668, where the rotary knob is disposed directly on one end of the colour zone adjusting screw, so that the shaft 21 and the pinion 22 are disposed of. In this type of arrangement the torque-limiting coupling can be arranged either exactly as in the example of operation, or between the pinion 17, which is then mounted loosely on the colour zone adjusting screw, and the colour zone adjusting screw.

1. An inking system for a printing machine, the system comprising an ink knife, adjusting means for adjusting the position of the knife, a motor for actuating said adjusting means, manually operable means for actuating said adjusting means, and a torque-limiting coupling between the motor and said manually operable means.

2. A system according to claim 1, wherein the motor is an electric motor.

3. A system according to claim 1 or 2, wherein a speed reducer is connected between the motor and said adjusting means, and said coupling is connected between said reducer and said manually

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Inking system for a printing machine This invention relates to inking systems for printing machines. German Gebrauchmuster 77 30 668 discloses a device for adjusting an ink knife which co-operates with a roller, of an inking system of a printing machine, with several colour zone adjusting screws distributed over the width of the ink knife, in which each colour zone adjusting screw is selectively adjustable either by means of an electric motor with a subsequently added reducer, or manually by means of a rotary knob. In this, the output shaft of the reducer is connected positively via pinions to the colour zone adjusting screw on which the rotary knob is also positively mounted. It has been shown that when the rotary knob is turned quickly by hand, such great forces come about in the reducer, that parts of the reducer can break. The present invention aims to provide a generally improved system. According to the peresent invention, there is provided an inking system for a printing machine, the system comprising an ink knife, adjusting means for adjusting the position of the knife, a motor for actuating said adjusting means, manually operable means for actuating said adjusting means, and a torque-limiting coupling between the motor and said manually operable means. In use of the invention, the coupling preferably reacts in the case of too quick a turning movement on the rotary knob, so that overloading of the motor is avoided. For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, the single figure of which shows a part-section through a device accord ing to the invention. The device comprises a support plate 1, on which a plate 4 is secured by means of screws 2 and spacers 3. The plate 4 carries a reducer 5 and an electric motor 6. Projecting through a recess 7 of the plate is a pivot pin 8, on which a shaft casing is positively mounted by means of a grub screw 9. The pivot pin 8 and the shaft casing 10 together form the output shaft of the reducer 5. A freely rotatable pinion 12 is mounted on to a bearing surface 11 of the shaft casing 10. The pinion 12 forms one part of a torque-limiting coupling. The other part of the coupling is a flange 16 on the shaft casing 10. To achieve the necessary counter pressure a counter pressure spring 15 is provided, which is designed as a plate spring.The counter pressure spring 15 is mounted on a support 14 and holds the pinion 12 in a position of frictional contact with the flange 16. The use of a plate spring has the advantage of taking up little space. In principle, however, other springs, e.g. a coil spring, can also be used. The support 14 is designed as a nut, which is screwed on to a thread 13 of the shaft casing. As a result of this arrangement the counter pressure of the spring can be applied and adjusted. The pinion 12 meshes with a further pinion 17, which is prevented from twisting, and mounted on a colour zone adjusting screw 18 in such a way that it is axially immovable. One end of the colour zone adjusting screw 18 is freely rotatable and adjustable in a bore of the support plate 1; the other end of the colour zone adjusting screw 18 cooperates with the ink knife, directly or via intermediary members, in a way which is known in itself and is not shown in any greater detail. The colour zone adjusting screw 18 also carries an external thread 19, which engages in the inner thread of a bearing 20 secured on the plate 4. In the support plate 1 there is also positioned a shaft 21, one end of which is firmly connected to a pinion 22. The pinion 22 also meshes with the pinion 12. The other end of the shaft 21 carries a rotary knob 23. If the output shaft 8, 10 of the reducer 5 is rotated to adjust the colour zone adjusting screw 18, the pinion 12 follows this movement as a result of its friction-contact position on the flange 16. As a result of this, the pinion 17 also rotates with the colour zone adjusting screw 18. Due to the engagement of the external thread 19 in the fixed bearing 20, an axial movement of the colour zone adjusting screw 18 is achieved. During this movement, the shaft 21 turns freely with the rotary knob 23. If the colour zone adjusting screw 18 is to be operated manually, the rotary knob 23 and therefore the shaft 21 are rotated. This rotation is transferred via the pinion 12 on to the pinion 17 of the colour zone adjusting screw, which, as a result, also undergoes an additional axial movement. If the rotation speed of the rotary knob exceeds a certain amount, then the torque-limiting coupling 12, 16 reacts and the pinion 12 slips with respect to the flange 16, so that no more rotation can be transferred to the output shafts 8, 10. The invention can also be used in an arrangement according to DE-GM 77 30 668, where the rotary knob is disposed directly on one end of the colour zone adjusting screw, so that the shaft 21 and the pinion 22 are disposed of. In this type of arrangement the torque-limiting coupling can be arranged either exactly as in the example of operation, or between the pinion 17, which is then mounted loosely on the colour zone adjusting screw, and the colour zone adjusting screw. CLAIMS

2. A system according to claim 1, wherein the motor is an electric motor.

3. A system according to claim 1 or 2, wherein a speed reducer is connected between the motor and said adjusting means, and said coupling is connected between said reducer and said manually operable means.

4. A system according to claim 1, 2 or 3, wherein said manually operable means comprises a rotary knob.

5. A system according to any preceding claim, wherein said adjusting means comprises a plurality of colour zone adjusting screws, distributed over the width of the knife, and each provided with a respective said motor, manually operable means, and coupling.

6. A system according to any preceding claim, including at least one inking roller, with which the ink knife co-operates.

7. A system according to any preceding claim, wherein the or each coupling is a spring-loaded friction coupling.

8. A system according to claim 7, wherein the or each coupling comprises a pinion which is rotatably mounted on a drive shaft which is arranged to be driven by the respective motor, the pinion being urged by a spring into a position of frictional contact with the drive shaft.

9. A system according to claim 8, wherein the or each pinion is urged by the respective spring into a position of frictional contact with a flange of the drive shaft.

10. A system according to claim 7,8 or 9, wherein the or each spring-loaded friction coupling comprises a plate spring.

11. Asystem according to claim 8,9 or 10, wherein the or each spring is maintained in position by a respective nut which threadedly engages the respective drive shaft and is adjustable in position to adjust the stress of the spring.

12. An inking system for a printing machine, the system being substantially as hereinbefore described with reference to the accompanying drawing.

13. A printing machine having an inking system according to any preceding claim.