US 4,133,264 A · Clamping assembly for thin printing plates

Abstract

A clamping apparatus is provided for holding thin flexible printing plates, especially Mylar printing plates, in position on a press cylinder. A metallic rigid clamp body is provided which is attachable to the press cylinder in a gap or groove formed between facing ends of plate supporting shims and/or edges of a groove formed in the press cylinder. A pivot bar having a serrated clamping edge is pivotally supported in the clamp body for cooperation with a fixed facing clamping surface of the clamp body to clamp the leading edge of the "Mylar" plate. A "Mylar" spring is provided for providing a continuous light biasing force on the pivot bar in the clamping direction. The clamping action of the pivot bar is by way of camming action and engagement of the serrated surface into the "Mylar" or other printing plate material, such that movement of the plate in a direction out of the clamping space tends to increase the clamping force of the pivot bar. The clamp body further slidably accommodates a tension bar which has a single fixed groove for engaging and holding the trailing edge of the printing plate. This tension bar is spring biased to a position corresponding to clamping of the printing plate trailing edge.

Claims21

Dependent claims

A clamping assembly for releasably clamping a thin flexible printing plate in position against an outwardly facing plate supporting surface on a press cylinder;

said clamping assembly comprising:
a clamp body having a plate edge clamping surface, and a pivot bar means having a pivot bar surface which is in facing relationship to said plate edge clamping surface, said pivot bar means being supported for pivotal movement between a first non-clamping position permitting insertion of a first edge portion of a printing plate between said pivot bar surface and said plate edge clamping surface and a second clamping position with said pivot bar surface clampingly forcing said first edge portion against said plate edge clamping surface and preventing withdrawal of said first edge portion,
wherein said clamp body is a rigid member having a first groove which opens in the radially outward direction when said clamp body is attached to a press cylinder, one side wall of said first groove constituting said plate edge clamping surface, and serving to engage the first edge of the plate wherein said rigid body further includes a second groove, said second groove serving to pivotally accommodate a corresponding portion of said pivot bar means, and
wherein said rigid member includes a third groove which extends linearly in a generally circumferential direction of said press cylinder when said clamp body is attached to the press cylinder, and wherein tension bar means having a radially extending groove for holding the second edge of the plate is slidably mounted in said third groove.

1 more element

A clamping assembly for releasably clamping a thin flexible printing plate in position against an outwardly facing plate supporting surface on a press cylinder;

said clamping assembly comprising:
a plurality of clamping members, a first of said clamping members being formed by a clamp body having a generally radially outwardly directed groove, one surface of said groove forming a plate edge clamping surface, and a second of said clamping members being formed by at least one pivot bar means located within said groove for clamping a first edge portion of a printing plate against said clamping surface, wherein said pivot bar means is supported by a socket-type pivotal interconnection between said clamp body and pivot bar means formed by a partially cylindrical portion of one of the first and second clamping members being rotatably retained within a partially cylindrical recess in the other of said clamping members for pivotal movement between a first non-clamping position, permitting insertion of said first edge between the clamping surface of the clamp body and a clamping portion of said pivot bar means which extends within said groove in facing relationship to said clamping surface, and a second clamping position, with said clamping portion forcing said first edge portion against said clamping surface preventing withdrawal of the first edge, and wherein spring means for biasing said pivot bar means toward said second position is provided within said groove.

Dependencies are inferred from the claim text.

Clamping assembly for thin printing plates

Life of this patent

Clamping assembly for thin printing plates

Life of this patent

Abstract

Claims21