GB2284389A

GB2284389A - Removing sleeves from printing cylinders

Info

Publication number: GB2284389A
Application number: GB9424420A
Authority: GB
Inventors: Wolfgang Prem; Anton Stadlmair
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1993-12-03
Filing date: 1994-12-02
Publication date: 1995-06-07
Anticipated expiration: 2014-12-02
Also published as: ITRM940761A1; ITRM940761A0; CA2137089A1; GB2284389B; FR2713142B1; JP2638754B2; FR2713142A1; IT1275343B; GB9424420D0; DE4341246C1; JPH07195669A

Description

2284389 Device for handling sleeves on cylinders The invention relates to

a device for handling sleeves on cylinders, in particular for securing sleeves such as printing formes or rubber-coating sleeves on cylinders of a rotary printing machine, in which the cylinders provided for receiving sleeves are mounted in cantilever fashion at one end fixed in the printing machine, and are accessible from the other end so that a sleeve can be pushed on or removed from the exposed end of the,cylinder.

Printing unit cylinders and sleeves of this type, whether it be a sleeveshaped printing forme for a forme cylinder or a rubber sleeve for an impression cylinder, are already known, for instance, from European Patent Application EP 02 77 545 A2.

In order to change the sleeves an air cushion is produced between the cylinder casing and the sleeve inner wall by means of compressed air flowing out of the cylinder core, and on this cushion the sleeve can be pushed on to the cylinder in the axial direction. Removal of the compressed air causes a form-fitting or shrink-fit application of the sleeve to the cylinder. By renewed supply of compressed air the sleeve can again be slid off the cylinder.

It is also necessary for the printing unit side wall to have an aperture whose diameter is greater than the diameter of the respective printing unit cylinder. Each cylinder provided for receiving sleeves is mounted in cantilever fashion at one end fixed in the printing machine and can be exposed at the outer end, on the operator side, by forming a side wall aperture. For this purpose a jaw chuck is provided with two jaws which are reciprocally movable in the plane of this printing unit side wall for holding the cylinder.

To guide a sleeve in and out through the open printing unit side wall it has been necessary until now to remove the paper web running between the impression cylinders so that the operator can stand in the printing unit and push or pull the sleeve through the side wall aperture for dismantling or assembly. These steps consequently require a long installation time.

It is therefore the aim of the present invention to produce a device for handling sleeves on cylinders, in particular for printing unit cylinders in a rotary printing machine of the type according to the opening paragraph, by means of which the removal of sleeves from the printing unit is possible without manual engagement into the printing unit, where the sleeve can be a printing forme, a rubber blanket or a half-tone sleeve.

According to the present invention there is provided a device for handling sleeves on printing cylinders mounted in cantilever fashion at one end and accessible at the other end for applying or removing the sleeve, the device having a sleeve-gripping means to be associated with the cylinder and a drive means for moving the sleeve-gripping means, and hence the sleeve, in the axial direction of the cylinder between the side walls of the printing unit.

By providing a mechanism for moving the sleeve in the axial direction on the cylinder on all cylinders intended to receive sleeves it is possible to move the sleeves axially on their respective cylinders so that they can be assembled or dismantled without difficulty through a side wall aperture by an operator or an automatic feeding or gripping device, without the operator reaching into the machine and without removing the web. 5 In addition it is advantageous to assign a paperdeflection device to each impression cylinder; this helps to leave the paper web under tension between the impression cylinders while at the same time assembling or dismantling the sleeves, in contrast to former practice. The deflection device can be controlled simultaneously with the sleeve actuator.

For a better understanding of the invention an embodiment of it will now be described in detail by means of the attached schematic drawings, in which:

Fig. 1 and 2 respectively show cross-sections through two impression cylinders of a printing unit with the paper web inserted in two different paper-deflection positions; Fig. 3 is a side view of a printing unit cylinder showing the sleeve- moving device; and Fig. 4 to 5 are side views - partially in section - of successive stages of the axial movement of a sleeve being removed from the cylinder.

Figs. 1 and 2 show two impression cylinders 1, 2 of a printing unit for the purpose of exchanging a sleeve whilst the machine is stopped, with fitted sleeves 3, 4 constituting in this case respective rubber blankets. A paper web 5 is inserted between the impression cylinders 1, 2. A swivel arm 6, 7 in the form of a pneumatic cylinder with a piston rod 8, 9 movable in a direction tangential to the associated cylinder 1, 2 is secured in the printing unit, one on each side of the paper web 5. A bar 10, 11 extending parallel to the axis of the respective impression cylinder 1 or 2 is 5 coupled to each piston rod 8, 9.

The bars 10, 11 can be moved in such a way by the respective pneumatic cylinders 6 or 7 that, after the machine has been stopped in the usual manner, the paper web 5 passing through the printing unit can be urged away from the impression cylinder 1 or 2 whose sleeve is to be changed or mounted. The web is pressed in the region of the printing gap towards the opposite impression cylinder 2 or 1. These steps are advantageously assisted by paper guide plates 12, 13 arranged on both sides of the paper web 5 in front of the printing gap.

In this way, therefore, the paper web 5 in the printing gap can be pivoted away from the lower impression cylinder 2 by the cylinder 7 and can be pressed against the upper impression cylinder 1 so that now the sleeve 4 on the lower cylinder can be dismantled or mounted without the paper web 5 being touched or damaged (Fig. 1). The same applies when removing or mounting the sleeve 3 on the upper cylinder 1. In this case the web-tensioned paper web 5 is pivoted away from the cylinder 1 (Fig. 2).

Preferably the sliding of the sleeve on to or off the cylinder is done automatically. The embodiment shown in Figure 3 includes a suitable sleeve-changing device. Fig. 3 shows a printing unit cylinder 22, which may be a forme cylinder or an impression cylinder, mounted between two side walls 20, 21. The cylinder 22 is mounted slidably or pivotably in a known manner, not described in detail here, for the purpose of setting against other cylinders. The cylinder 22 is mounted in cantilever fashion, with a permanent bearing at one end in the side wall 21, while at the other end the bearing can be removed to allow sleeve exchange. At this end, here the printing unit side wall 20, there is provided a side wall aperture 23 whose diameter is greater than the diameter of the sleeve 24 located on the cylinder 22.

To expose the cylinder 22, a chuck jaw comprising two jaws 25, 26 forming the removable bearing is provided on the side wall 20. The jaws can be reciprocally moved in the direction of the arrows in the plane of the side wall 20 so that movement of the sleeve 24 through this side wall aperture 23 is possible.

A rail-like guideway 27 extending parallel to the axis of the cylinder 22 is fitted between the two side walls 20, 21. On this guideway 27, travelling between the surface of the cylinder and the rail, there is placed a movable guide element 28 which faces the cylinder surface and can be brought into contact with the sleeve 24. This guide element 28 is coupled to a drive 29 secured on the rail-like quideway 27 and in the form of a pneumatic cylinder by means of the cylinder's piston rod 30.

This sleeve-gripping system 27, 28, 29, 30 for the correctly positioned movement of the sleeve 24 is preferably integrated into a shielding bar in front of the printing gap of a pair of printing cylinders to protect the fingers of an operator.

Figs. 4 to 6 show in more detail this system 27, 28, 29, 30 for moving the sleeve 24.

The distance of such a movement of the sleeve 24 on the cylinder 22 is on the one hand determined by the length of the piston rod 30, and on the other hand defined by grooves 31, 32 located on the rail-like guideway. The guide element 28 is constructed as a clamping piece for contact with the sleeve 24 and has a control pin 34 axially movable in a housing 36 in a direction perpendicular to the cylinder axis against a compression spring 33. The ends of the pin 34 protrude from the housing 36. At one end the control pin 34 scans the groove geometry 31, 32 as the guide element 28 is moved an the quideway 27 by means of the piston rod 30, and in dependence on the groove geometry 31, 32 it lifts or lowers a friction lining 35 on the other end against or away from the sleeve 24.

If the sleeve 24 mounted on the cylinder 22 is to be dismantled the press fit of the sleeve 24 is released in the usual way by a supply of compressed air and hence the sleeve 24 is made movable on the cylinder 22. The piston rod 30 of the drive 29 is moved out and the control pin is lifted against the compression spring 33 by the changing groove geometry of the groove 32 as the pin rides up from the lower to the upper groove level so that the friction lining is pressed against the sleeve 24 (Fig. 5).

During further linear movement in the outward direction of movement (arrow A) the sleeve 24 is entrained by the guide element 28 and thus slides off the cylinder. The pin 34 then encounters the second groove 31, whereupon it lifts off the sleeve 24, and the contact between the friction lining 35 and the sleeve 24 is interrupted (Fig. 6).

The sleeve 24 can be moved on the cylinder 22 over this predetermined distance between the grooves 31 and 32 sufficiently far between the side walls 20, 21 for it to be completely pulled off the cylinder 22 through the side wall aperture 23 manually or completely automatically and removed from the printing unit 22 without any problem.

Mounting of a sleeve is carried out in reverse sequence. For both processes the installation time is considerably reduced.

Obviously the contact between sleeve 24 and guide element 28, necessary for the axial movement of the sleeve 24 on the cylinder 22, can also be produced in any appropriate way, for instance by means of vacuum suction units or in the broadest sense a hook. Similarly the triggering of its engagement of the cylinder can be done mechanically, electrically or optically as desired.

Claims

1. Device for handling sleeves on printing cylinders mounted in cantilever fashion at one end and accessible at the other end for applying or removing the sleeve, the device having a sleeve-gripping means (27 to 30) to be associated with the cylinder (1, 2, 22) and a drive means (29) for moving the sleeve-gripping means, and hence the sleeve, in the axial direction of the cylinder between the side walls (20, 21) of the printing unit.

2. Device for handling sleeves on printing cylinders mounted in cantilever fashion at one end and accessible at the other end for applying or removing the sleeve, in which a paper web deflection device (6 to 11) is provided for spacing a paper web (5) running through the printing unit from the cylinder whose sleeve is to be handled.

3. Device for handling sleeves on cylinders according to claim 2, in which the paper deflection device (6 to 11) has at least one arm (6 or 7) which is coupled to at least one bar (10 or 11) arranged parallel to the axis of the respective cylinder (1 or 2), by means of which the paper web (5) can be moved away from the respective cylinder (1 or 2) when the arm (6 or 7) is actuated.

4. Device for handling sleeves on cylinders according to claim 3, in which the arm (6, 7) is a pneumatic cylinder by whose piston rod (8, g), together with the coupled bar (10, 11), the paper web (5) can be pressed away from the impression cylinder (1, 2).

5. Device for handling sleeves on cylinders according -g- to any preceding claim and including two paperdeflection devices (6 to 11) for arrangement on both sides of the paper web (5) extending in the printing gap of two impression cylinders (1, 2) in such a way that with the impression cylinders (1, 2) in nonprinting mode the paper web (5) can be swung away from one of the impression cylinders (1 or 2) and pressed against the other impression cylinder (2 or 1).

6. Device for handling sleeves on cylinders according to claim 1, in which the sleeve-gripping system (27 to 30) includes a rail-like guideway (27) arranged parallel to the axis of the cylinder (1, 2, 22), a movably arranged guide element (28) which can be brought into contact with the sleeve (22) is placed on the quideway (27) in order to move the sleeve (22), and the drive (29) is coupled to the guide element (28).

7. Device for handling sleeves on cylinders according to claim 6, in which the drive (29) is a pneumatic cylinder whose piston rod (30), coupled to the guide element (28), can move the sleeve (24) a specific distance on the cylinder (22).

8. Device for handling sleeves on cylinders according to claim 7, in which the guide element (28) is constructed as a clamping piece provided with a friction lining (35), the clamping piece has a control pin (34) which can be moved in the direction perpendicular to the cylinder axis against a compression spring (33) for contact with the sleeve (24), the movement of this control pin being controllable by a profile (31, 32) on the rail-like guideway (27), in such a way that by the movement of the control pin (34) the friction lining (35) of the clamping piece (28) can be brought into contact with -10the sleeve (24) or lifted off it.

9. Device for handling sleeves on cylinders according to claim 1 or 6 to 8, in which the system (27 to 30) for moving the sleeve (24) in the axial direction on the cylinder (22) is integrated into a shielding rod to be placed in front of the printing gap of two opposite printing unit cylinders to protect the fingers of an operator.

10. A device for handling sleeves, substantially as described hereinbefore with reference to the accompanying drawings.

11. A printing machine including at least one cylinder with a sleeve and a sleeve-handling device as claimed in any preceding claim.

12. A method of handling a sleeve on a printing cylinder in a printing machine, in which the print web is lifted from the cylinder without being removed from the machine, and the sleeve is removed from or placed on the cylinder.

6,