Printing plate clamping assembly

Apparatus for detachably holding thin flexible printing plates in position on a cylindrically shaped press cylinder comprising:

• shim means configured to accurately radially position a printing plate with respect to the cylindrical outwardly facing surface of the press cylinder,
• shim attaching means for attaching said shim means to the press cylinder with respective oppositely circumferentially facing shim edge portions being spaced from one another to form a gap there between,
• a clamping assembly for releasably clamping a first plate edge portion of said printing plate to said press cylinder with said printing plate engaged against an outwardly facing plate supporting surface of said shim means,
• and clamping assembly attaching means for detachably attaching said clamping assembly to said press cylinder, said clamping assembly attaching means being separate from said shim attaching means,
• said shim means and clamping assembly being dimensioned and configured such that said clamping assembly fits within said gap without protruding radially outwardly beyond the radial outward extent of said shim means when in an operating position clamped to said press cylinder, wherein said clamping assembly includes:
• a base member detachably attachable to said press cylinder means,
• hinge pin means supported at said base member,
• clamp member means attached to said hinge pin means for pivotal movement about a hinge pin axis between a clamping position with said clamp member means clampingly engaged in plate detent means of said first plate edge portion and a non-clamping position out of engagement with said plate detent means,
• and resilient means for continuously resiliently rotationally biasing said clamp member means towards said clamping position, and
• wherein said hinge pin means is constructed as a single hinge pin for supporting two clamp member means which are clampingly pivotal in respective opposite directions to facilitate reversal of the circumferential direction of the printing plate being clamped.

Apparatus for detachably holding thin flexible printing plates in position on a cylindrically shaped press cylinder comprising:

• shim means configured to accurately radially position a printing plate with respect to the cylindrical outwardly facing surface of the press cylinder,
• shim attaching means for attaching said shim means to the press cylinder with respective oppositely circumferentially facing shim edge portions being spaced from one another to form a gap there between,
• a clamping assembly for releasably clamping a first plate edge portion of said printing plate to said press cylinder with said printing plate engaged against an outwardly facing plate supporting surface of said shim means,
• and clamping assembly attaching means for detachably attaching said clamping assembly to said press cylinder, said clamping assembly attaching means being separate from said shim attaching means,
• said shim means and clamping assembly being dimensioned and configured such that said clamping assembly fits within said gap without protruding radially outwardly beyond the radial outward extent of said shim means when in an operating position clamped to said press cylinder, wherein said clamping assembly includes:
• a base member detachably attachable to said press cylinder means,
• hinge pin means supported at said base member,
• clamp member means attached to said hinge pin means for pivotal movement about a hinge pin axis between a clamping position with said clamp member means clampingly engaged in plate detent means of said first plate edge portion and a non-clamping position out of engagement with said plate detent means,
• and resilient means for continuously resiliently rotationally biasing said clamp member means towards said clamping position, and
• wherein said hinge pin means is constructed as a pair of parallel hinge pins for supporting respective separate clamp member means which are clampingly pivotal in respective opposite direction to facilitate reversal of the circumferential directions of the printing plate being clamped.

Apparatus for releasably clamping a plate edge portion of a thin flexible printing plate to press cylinder means with said printing plate supported in an in-use printing position on a circumferential surface of said press cylinder means;

• said apparatus including:
• a base member attachable to a radially outwardly facing surface of a press cylinder,
• hinge pin means supported at said base member,
• clamp member means attached to said hinge pin means for pivotal movement about a hinge pin axis between a clamping position with said clamp member means clampingly engaged in plate detent means of said plate edge portion and a non-clamping position out of engagement with said plate detent means,
• and resilient means for continuously resiliently rotationally biasing said clamp member means toward said clamping position wherein said hinge pin means is constructed as a single hinge pin for supporting two clamp members which are clampingly pivotal in respective opposite directions to facilitate reversal of the circumferential direction of the printing plate being clamped, said clamp members being separately movable with respect to one another.

Apparatus for detachably holding thin flexible printing plates in position on a cylindrically shaped press cylinder comprising:

• a clamping assembly for releasably clamping a first plate edge portion of said printing plate to said press cylinder with said printing plate engaged against an outwardly facing plate supporting surface at the press cylinder,
• and clamping assembly attaching means for detachably attaching said clamping assembly to said press cylinder,
• said clamping assembly and clamping assembly attaching means being dimensioned and configured such that they fit completely within a gap at said press cylinder having a radial height corresponding to the difference in thickness of the thin flexible printing plate and earlier used lead stereotype plates;
• whereby said clamping assembly can be attached directly to the outer cylindrical surface of a press cylinder having shim means without requiring additional groove means at the press cylinder or can be attached directly to a press cylinder in a groove of the press cylinder, which groove has a radial dimension corresponding to the thickness of such shim means,
• wherein said clamping assembly includes:
• a base member detachably attachable to said press cylinder,
• hinge pin means supported at said base member,
• clamp member means attached to said hinge pin means for pivotal movement about a hinge pin axis between a clamping position with said clamping member means clampingly engaged in plate detent means of said first plate edge portion and a non-clamping position out of engagement with said plate detent means,
• and resilient means for continuously resiliently rotationally biasing said clamp member means towards said clamping position,
• wherein said hinge pin means is constructed as a single hinge pin for supporting two clamp member means which are clampingly pivotal in respective opposite directions to facilitate reversal of the circumferential direction of the printing plate being clamped, and wherein a single set of spiral spring means surrounding said hinge pin serves to resiliently bias both of said clamp member means towards their respective clamping positions.

Apparatus for detachably holding thin flexible printing plates in position on a cylindrically shaped press cylinder comprising:

• a clamping assembly for releasably clamping a first plate edge portion of said printing plate to said press cylinder with said printing plate engaged against an outwardly facing plate supporting surface at the press cylinder,
• and clamping assembly attaching means for detachably attaching said clamping assembly to said press cylinder,
• said clamping assembly and clamping assembly attaching means being dimensioned and configured such that they fit completely with a gap at said press cylinder having a radial height corresponding to the difference in thickness of the thin flexible printing plate and earlier used lead stereotype plates;
• whereby said clamping assembly can be attached directly to the outer cylindrical surface of a press cylinder having shim means without requiring additional groove means at the press cylinder or can be attached directly to a press cylinder in a groove of the press cylinder, which groove has a radial dimension corresponding to the thickness of such shim means,
• wherein said clamping assembly includes:
• a base member detachably attached to said press cylinder,
• hinge pin means supported at said base member,
• clamp member means attached to said hinge pin means for pivotal movement about a hinge pin axis between a clamping position with said clamp member means clampingly engaged in plate detent means of said first plate edge portion and a non-clamping position out of engagement with said plate detent means,
• and resilient means for continuously resiliently rotationally biasing said clamp member means towards said clamping position, and
• wherein said clamp assembly includes alignment clip means engageable with detent means of said second plate edge for aligning said second plate edge in the direction parallel to the rotational axis of the press cylinder, said alignment clip means being formed separately of said base member and clamp member means.

Apparatus for releasably clamping a plate edge portion of a thin flexible printing plate to press cylinder means with said printing plate supported in an in-use printing position on a circumferential surface of said press cylinder means;

• said apparatus including:
• a base member attachable to a radially outwardly facing surface of a press cylinder,
• hinge pin means supported at said base member,
• clamp member means attached to said hinge pin means for pivotal movement about a hinge pin axis between a clamping position with said clamp member means clampingly engaged in plate detent means of said plate edge portion and a non-clamping position out of engagement with said plate detent means,
• and resilient means for continuously resiliently rotationally biasing said clamp member means toward said clamping position,
• wherein said clamping assembly includes alignment clip means engageable with detent means of a second plate edge portion of said plate opposite said first-mentioned plate edge portion for aligning said second plate edge portion in the lateral direction, said alignment clip means being formed separately of said base member and clamp member means.

Method of preparing an existing press cylinder designed for utilizing thick lead stereotype printing plates to be used with thin flexible printing plates;

• said method comprising:
• attaching shim means directly to the outer cylindrical surface of said press cylinder,
• and detachably attaching a printing plate clamping assembly directly to the outer cylindrical surface of said press cylinder at a position intermediate facing edge portions of said shim means,
• said printing plate clamping assembly being separate from said shim means and dimensioned and configured such that said shim means and said printing plate clamping assembly can be attached to and detached from said press cylinder independently of one another.

Apparatus for releasably clamping a plate edge portion of a thin flexible printing plate to press cylinder means with said printing plate supported in an in-use printing position on a circumferential surface of said press cylinder means;

• said apparatus including:
• a base member,
• hinge pin means carried by said base member,
• clamp member means pivotally movable about said hinge pin means, said clamp member means being directly engageable with said first plate edge portion when in a clamping position,
• resilient means for resiliently biasing said clamp member means towards its clamping position,
• tool means selectively engageable in recess means of said clamp member means for forcibly moving said clamp member means toward a non-clamping position to accommodate engagement of said plate detent means with said clamp member means,
• and aperture means in said base member for accommodating insertion of bolts therethrough to clamp said base member to the surface of said press cylinder, said bolts forming at least part of said clamping assembly attaching means,
• wherein said clamp member means and said aperture means are disposed such that said clamp member means covers said aperture means in the radial outward direction when in a clamping position, and wherein said aperture means are uncovered in the radial direction when said clamp member means is in an unclamping position, whereby attaching and detaching of said clamping assembly can be accommodated by movement of said clamp member means to the non-clamping position thereof.