GB2034639A

GB2034639A - Printing machine cylinder with detachable bearing ring

Info

Publication number: GB2034639A
Application number: GB7938030A
Authority: GB
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1978-11-04
Filing date: 1979-11-02
Publication date: 1980-06-11
Also published as: SE7909076L; FR2440832A1; JPS5565555A; DE2847880A1

Abstract

The bearer ring 5 has an inner frusto-conical seating 6 and the cylinder shaft 2 carries a corresponding frusto- conical seating 4 with a bore hole opening into it for supplying a pressure medium to between the co-operating seating surfaces for dismounting the bearer ring. The seating in the cylinder shaft 2 may be an integral section 3 of larger diameter or it may be provided by an intermediate ring mounted on the shaft. The greatest diameter of the frusto-conical seatings may face the cylinder and the gradient of the frusto- conical seatings be such as to be self locking; alternatively, the smaller diameter of the frusto-conical seatings may face the cylinder with the shaft seating being provided by a removable intermediate ring. <IMAGE>

Description

SPECIFICATION Printing machine cylinder having a detachable bearer ring This invention relates to a printing machine cylinder having a detachable bearer ring mounted on its shaft.

Known detachable bearer rings in general use tend to involve the bearer ring fitting with a press fit on a cylindrical section ofthe cylinder shaft. This means that the bearer ring must be heated to enable it to be lifted onto the shaft. The bearer ring can distort, both as a result of the heating, and because of the radial forces generated in the bearer ring, which it is not possible to predetermine exactly.

Thus in such cases it is usually necessary to regrind the bearer ring once it has been pressed onto the shaft, since its rotational bearer surface must be true if it is to fulfill its function. When the bearer ring is replaced, the entire printing cylinder must therefore be transported to the manufacturer after dismantling, since the heating and precise regrinding required cannot be carried out in a printing works.

An object of the invention is to provide a method of fastening a bearer ring which will simplify the replacement of a one-piece bearer ring placed on the cylinder, so that replacement can be carried out where the printing machine is erected.

According to the present invention there is provided a printing machine cylinder having a detachable bearer ring which is adapted to be mounted on its shaft, in which the bearer ring has an inner frusto-conical seating, and the cylinder shaft carries a corresponding frusto-conical seating with at least one bore hole which opens into the frusto-conical seating surface for the purpose of supplying a pressure medium to between the co-operating seating surfaces.

This construction in accordance with the invention, ensures that the bearer ring need no longer be heated before being lifted onto the shaft, so there is no longer any danger that distortion will result from this process. In addition to this the bearer ring is afforded a seat which guarantees even distribution of the radial forces over the entire circumference, so that distortion cannot occur as a result of this problem either. The magnitude of the effective radial forces can be controlled by the exertion of more or less pressure between the mating frusto-conical seatings. The bearer ring can, however, easily be detached from the opposite seating carried by the shaft for dismantling by applying high pressure fluid to the bore hole in the opposite seating without the danger of damage to the seatings.Since it is thus possible to detach the bearer ring from the cylinder shaft efficiently and without risk of damage, and since heat treatment and regrinding are no longer necessary, the replacement of the bearer ring can take place within the printing works.

The invention may be put into practice in a number of ways but certain specific embodiments will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a first embodiment of a bearer ring and printing machine cylinder with the bearer ring shown in section, and Figures 2 and 3 show two further embodiments, each corresponding to the representation in Figure 1.

In Figure 1 the printing machine cylinder 1 which can be a laminated or a rubber cylinder, is firmly connected to a shaft 2, which has a section 3.of greater diameter than the diameter of the shaft 2 proper. The surface of the outer circumference of the section 3 is in the form of a frusto-conical seating 4.

The bearer ring 5 is placed with its innerfrustoconical seating 6 of the corresponding seating 4. The greatest diameter of each frusto-conical section thus faces, i.e. is nearest to, the cylinder 1. The frustoconical surfaces of the two seatings 4 and 6 have identical gradients. The gradient is chosen so that it is within the range of self-locking whereby the bearer ring remains securely mounted on the seating by virtue of the frictional co-operation between the frusto-conical seating surfaces. It has been found expedient to use a gradient (taper angle), i.e. the ratio (d2-d1)/1, of 1:30, where 1 is the length of the bearer ring, d1 the smallest diameter of the conical seating, and d2 the greatest diameter of this seating.

A bore hole 7 is provided in the seating 4 and this is connected to an additional supply bore hold 8. A pressure medium source, e.g. a pump which delivers hydraulic fluid at high pressure, can be connected to the supply bore hole 8. A distribution groove 9 which runs around the circumference of the section 3, communicates with the end of the bore hole 7 in the seating 6.

When the bearer ring 5 is to be dismantled, the pressure medium source is connected to the supply bore hole 7, and pressure fluid is introduced between the seating 6 and the opposite seating 4 to relieve the frictional contact pressure between the surfaces of those seatings and enable the bearer ring 5 to be drawn off the seating 4. The bearer ring 5 can thus be removed easily from its position without the use of great force or the risk of damage. In order to install a new bearer ring, the latter must first of all be pushed by hand onto the opposite seating 4. The bearer ring 5 is then pushed further onto the opposite seating 4, e.g. by means of a hydraulic pressing tool, until a specific pressure is reached.

According to the arrangement in Figure 2, a printing machine cylinder 10 is provided with a completely cylindrical shaft 11 running through it.

An intermediate ring 12 is placed on the shaft 11. The mounting of the intermediate ring 12 on the shaft 11 is such as to ensure that the intermediate ring can not be moved by hand. The intermediate ring 12 has a section which forms a frusto-conical opposite seating 13, upon which is placed a bearer ring 14, also with a frusto-conical radially-inner seating 15.

The greatest diameter of each frusto-conical seating again faces the cylinder 10. In this example too there is a bore hole 16 which opens into the opposite seating 13, and is connected to a further supply bore hole 17. The connection to the pressure medium source can be screwed into the outward-facing end ofthe supply bore hole 17.

Whilst according to the arrangements in Figure 1 and 2, the bearer rings 5 and 14 respectively can be removed without disturbing any other components but are only secured on the shaft by the self-locking taper of the mating frusto-conical surfaces, Figure 3 shows an arrangement whereby the connection as such ensures greater security with regard to an axial movement of the bearer ring. Here again an intermediate ring 22 is placed on the cylindrical shaft 20 of a cylinder 21; the outer surface of the intermediate ring 22 forms the opposite frusto-conical seating 23, upon which a bearer ring 24 is fitted with its frusto-conical seating 25. Again, at least one bore hole opens into the opposite seating 23 for the introduction of a pressure medium. However, in contrast to the two previous embodiments, the arrangement here is such that the smallest diameter of each of the frusto-conical seatings faces the cylinder 21. Therefore, in order to dismantle the bearer ring 24, one must in this case also remove the intermediate ring 22 from the shaft 20.

Claims

1. A printing machine cylinder having a detachable bearer ring which is adapted to be mounted on its shaft, in which the bearer ring has an inner frusto-conical seating, and the cylinder shaft carries a corresponding frust-conical seating with at least one bore hole which opens into the frusto-conical seating surface for the purpose of supplying a pressure medium to between the co-operating seating surfaces.

2. A printing machine cylinder and bearer ring as claimed in claim 1, in which the shaft of the cylinder is equipped with an integral section which is provided with the corresponding frusto-conical seating.

3. A printing machine cylinder and bearer ring as claimed in claim 1, in which an intermediate ring affording the corresponding frusto-conical seating is mounted on the cylindrical shaft of the cylinder.

4. A printing machine cylinder and bearer ring as claimed in any one of the preceding claims, in which the greatest diameter of the mating frusto-conical seatings faces the cylinder, and the frusto-conical seatings have a gradient (taper angle) which is within the range of self-locking.

5. A printing machine cylinder and bearer ring as claimed in claim 4, in which the gradient of the frusto-conical seatings is approximately 1:30.

6. A printing machine cylinder and bearer ring as claimed in claim 3, in which the smallest diameter of the mating frusto-conical seatings faces the cylinder, and the intermediate ring which bears the said corresponding frusto-conical seating is placed on the shaft of the cylinder in such a way that it is removable therefrom.

7. A printing machine cylinder and bearer ring as claimed in any one of the preceding claims, in which a distribution groove running around the peripheral surface of the said corresponding frusto-conical seating is connected to the bore hole or bore holes.

8. A bearer ring for a printing machine cylinder having a central through bore with a frusto-conical inner seating-surface which is adapted to be mounted on a corresponding frusto-conical seating carried by the cylinder shaft.

9. A bearer ring as claimed in claim 8, in which the frusto-conical inner seating has a gradient such that it is adpated to form a self-locking mounting on the corresponding frusto-conical seating carried by the cylinder shaft.

10. A printing machine cylinder and bearer ring substantially as specifically described herein with reference to Figure 1, or to Figure 2, or to Figure 3 of the accompanying drawings.