GB2048171A

GB2048171A - Impression cylinder

Info

Publication number: GB2048171A
Application number: GB8013242A
Authority: GB
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1979-04-24
Filing date: 1980-04-22
Publication date: 1980-12-10
Also published as: GB2048171B; IT8021532A0; FR2454912B2; IT1140888B; DE2916434A1; FR2454912A2

Abstract

The invention discloses an impression cylinder (1) having a printing blanket (3) secured thereto. The lower end (4) of the printing blanket (3), facing in the direction of rotation (a) of the cylinder (1), is located in a groove (11) formed in the outer surface of the cylinder (1) and being of a depth corresponding to its wall thickness, and wherein the printing blanket section (4), located within the groove is covered, at least partially, by the other end (5) of the printing blanket (3). The groove (11), as illustrated in Fig. 1, has a substantially triangular cross-section and at its deepest point has a depth corresponding to the wall thickness of the end (4) of the printing blanket (3) facing in the direction of rotation (a) of the cylinder (1), and the end (5) of the printing blanket (3) facing in the opposite direction to the direction of rotation (a) of the cylinder (1) has a wall thickness tapering towards its end. Alternatively, as illustrated in Fig. 2, the groove (11) may have a flat rectangular cross-section having a depth corresponding to the wall thickness of the printing blanket (3). <IMAGE>

Description

SPECIFICATION Impression cylinder having a printing blanket secured thereto The present invention relates to an impression cylinder having a printing blanket secured thereto by adhesion or the like, in which the printing blanket extends around the surface of the cylinder by more than 3600, and the upper, free end of the printing blanket faces in the opposite direction to the direction of rotation of the cylinder. Such arrangement is described and claimed in our copending application No. 8007416.

It is an object of the present invention, whilst retaining the advantages proposed by such abovedescribed arrangement, to secure the printing blanket to the cylinder by developing the connecting point where the ends of the blanket overlap whereby a minimum amount of printing blanket material is utilised.

According to the present invention there is provided an impression cylinder having a printing blanket secured thereto by adhesion or the like, in which the printing blanket extends around the surface of the printing cylinder by more than 3600 and the upper, free end of the printing blanket faces in the opposite direction to the direction of rotation of the cylinder, wherein the lower end of the printing blanket, facing in the direction of rotation of the cylinder, is located in a groove formed in the outer surface of the cylinder and of a depth corresponding to its wall thickness, and wherein the printing blanket section located within the groove is covered, at least partially, by the other end of the printing blanket.

This overlap region may be relatively short, e.g.

formed so that its peripheral length amounts to only a few centimetres.

it is thus particularly favourable for the said groove to be substantially triangular in crosssection in such a manner that the lowermost point of this groove corresponds to the wall thickness of the blanket section to be accommodated in the groove. The end of the printing blanket facing in the opposite direction to the direction of rotation of the cylinder is then accordingly sharpened or so fashioned that it tapers into a point at its free end.

An end tapering into a point may be omitted if the end of the printing blanket facing in the direction of rotation is located in a substantially shallow, rectangular longitudinal groove provided in the outer surface of the cylinder. The depth of this groove over the entire peripheral length of the groove should be substantially identical to the wall thickness of the printing blanket.

It is to be understood that securing of the ends of the blanket in the overlap region is effected by a suitable adhesive to obtain operational efficiency.

It is also favourabie to fashion the overlap region in such a manner that the ends overlap one another by about 1 to 3 cm.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which: Figs. 1 and 2 each show a partial crosssectional view through a printing blanket cylinder, particularly the end sections of the printing blanket.

A printing blanket 3 made of rubber or rubberlike materials, and possibly having reinforcing plies is located on the printing blanket cylinder 1 and secured thereto by adhesion. Such adhesive connection is not only for securing the printing blanket 3 to the printing blanket cylinder 1, but also for the overlapping sections of the printing blanket 3.

As illustrated in Fig. 1, the printing blanket cylinder 1 has an axially parallel groove 11 formed in the outer surface thereof, which groove has a substantially triangular cross-section in such a manner that the deepest point corresponds to the wall thickness w of the printing blanket, and the length of the groove, seen in the peripheral direction of the cylinder 1, corresponds to about 100 of the angle of rotation of the cylinder 1. The end 4 of the printing blanket 3 inserted in the groove 11 points in the direction of rotation a of the printing blanket cylinder 1.The bevel resulting from the groove 11 on the surface of the end 4 is covered by the end 5 of the blanket 3 pointing in the opposite direction to the direction of rotation a, and which end 5 tapers in wall thickness towards its free end, and thus is sharpened so as to securely connect with the end 4. The arrangement is preferably such that a gradual transition in the outer surface of the printing cylinder 1 is created.

In the embodiment of Fig. 2, the groove 11 is flat shallow and rectangular; it extends over a peripheral length of about 2 to 3 cm and has a depth which corresponds to the wall thickness of the printing blanket 3. The end 4 may be securely anchored in this groove 11, whilst thereover the unprepared, obtusely extending, end 5 of the blanket 3 is secured by adhesion or the like. The remaining narrow recess at 12 may be fiiled with a suitable material.

1. An impression cylinder having a printing blanket secured thereto by adhesion or the like, in which the printing blanket extends around the surface of the printing cylinder by more than 3600 and the upper, free end of the printing blanket faces in the opposite direction to the direction of rotation of the cylinder, wherein the lower end of the printing blanket, facing in the direction of rotation of the cylinder is located in a groove formed in the outer surface of the cylinder and of a depth corresponding to its wall thickness, and wherein the printing blanket section located within the groove is covered, at least partially, by the other end of the printing blanket.

2. An impression cylinder having a printing blanket secured thereto as claimed in claim 1, in which the groove has a substantially triangular cross-section and at its deepest point has a depth corresponding to the wall thickness of the end of the printing blanket facing in the direction of rotation of the cylinder and wherein the end of the

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Impression cylinder having a printing blanket secured thereto The present invention relates to an impression cylinder having a printing blanket secured thereto by adhesion or the like, in which the printing blanket extends around the surface of the cylinder by more than 3600, and the upper, free end of the printing blanket faces in the opposite direction to the direction of rotation of the cylinder. Such arrangement is described and claimed in our copending application No. 8007416. It is an object of the present invention, whilst retaining the advantages proposed by such abovedescribed arrangement, to secure the printing blanket to the cylinder by developing the connecting point where the ends of the blanket overlap whereby a minimum amount of printing blanket material is utilised. According to the present invention there is provided an impression cylinder having a printing blanket secured thereto by adhesion or the like, in which the printing blanket extends around the surface of the printing cylinder by more than 3600 and the upper, free end of the printing blanket faces in the opposite direction to the direction of rotation of the cylinder, wherein the lower end of the printing blanket, facing in the direction of rotation of the cylinder, is located in a groove formed in the outer surface of the cylinder and of a depth corresponding to its wall thickness, and wherein the printing blanket section located within the groove is covered, at least partially, by the other end of the printing blanket. This overlap region may be relatively short, e.g. formed so that its peripheral length amounts to only a few centimetres. it is thus particularly favourable for the said groove to be substantially triangular in crosssection in such a manner that the lowermost point of this groove corresponds to the wall thickness of the blanket section to be accommodated in the groove. The end of the printing blanket facing in the opposite direction to the direction of rotation of the cylinder is then accordingly sharpened or so fashioned that it tapers into a point at its free end. An end tapering into a point may be omitted if the end of the printing blanket facing in the direction of rotation is located in a substantially shallow, rectangular longitudinal groove provided in the outer surface of the cylinder. The depth of this groove over the entire peripheral length of the groove should be substantially identical to the wall thickness of the printing blanket. It is to be understood that securing of the ends of the blanket in the overlap region is effected by a suitable adhesive to obtain operational efficiency. It is also favourabie to fashion the overlap region in such a manner that the ends overlap one another by about 1 to 3 cm. The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which: Figs. 1 and 2 each show a partial crosssectional view through a printing blanket cylinder, particularly the end sections of the printing blanket. A printing blanket 3 made of rubber or rubberlike materials, and possibly having reinforcing plies is located on the printing blanket cylinder 1 and secured thereto by adhesion. Such adhesive connection is not only for securing the printing blanket 3 to the printing blanket cylinder 1, but also for the overlapping sections of the printing blanket 3. As illustrated in Fig. 1, the printing blanket cylinder 1 has an axially parallel groove 11 formed in the outer surface thereof, which groove has a substantially triangular cross-section in such a manner that the deepest point corresponds to the wall thickness w of the printing blanket, and the length of the groove, seen in the peripheral direction of the cylinder 1, corresponds to about 100 of the angle of rotation of the cylinder 1. The end 4 of the printing blanket 3 inserted in the groove 11 points in the direction of rotation a of the printing blanket cylinder 1.The bevel resulting from the groove 11 on the surface of the end 4 is covered by the end 5 of the blanket 3 pointing in the opposite direction to the direction of rotation a, and which end 5 tapers in wall thickness towards its free end, and thus is sharpened so as to securely connect with the end 4. The arrangement is preferably such that a gradual transition in the outer surface of the printing cylinder 1 is created. In the embodiment of Fig. 2, the groove 11 is flat shallow and rectangular; it extends over a peripheral length of about 2 to 3 cm and has a depth which corresponds to the wall thickness of the printing blanket 3. The end 4 may be securely anchored in this groove 11, whilst thereover the unprepared, obtusely extending, end 5 of the blanket 3 is secured by adhesion or the like. The remaining narrow recess at 12 may be fiiled with a suitable material. CLAIMS

2. An impression cylinder having a printing blanket secured thereto as claimed in claim 1, in which the groove has a substantially triangular cross-section and at its deepest point has a depth corresponding to the wall thickness of the end of the printing blanket facing in the direction of rotation of the cylinder and wherein the end of the printing blanket facing in the opposite direction to the direction of rotation of the cylinder has a wall thickness tapering towards its end.

3. An impression cylinder having a printing blanket secured thereto as claimed in claim 1, in which the groove has a flat, rectangular crosssection having a depth corresponding to the wall thickness of the printing blanket.

4. An impression cylinder having a printing blanket secured thereto as claimed in claim 3, in which the end of the printing blanket facing in the opposite direction to the direction of rotation of the cylinder has a uniform wall thickness up to its front end face.

5. An impression cylinder having a printing -blanket secured thereto as claimed in any preceding claim in which the overlap region of the ends of the printing blanket, seen in the peripheral direction of the printing blanket cylinder, amounts to 1 to 3 cm.

6. An impression cylinder having a printing blanket secured thereto as claimed in any preceding claim, in which the groove has a length, seen in the peripheral direction of the cylinder, corresponding to about 100 of the angle of rotation of the cylinder.

7. An impression cylinder having a printing blanket secured thereto, substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Fig. 2 of the accompanying drawings.