Patent GB-646717-A (GB)
Title: Mechanism for registering printing plates
IPC: B41F27/00
Filed: 1947-08-08
Abstract: 646,717. Printing-surfaces. HOE & CRABTREE, Ltd., R. Aug. 8, 1947, No. 22125. Convention date, Feb. 13, 1942. [Class 100 (ii)] Apparatus for pre-registering to one another a number of flexible printing-plates of a set so that register marks similarly located on each plate may be located in correspondingpositions on forme cylinders, each plate having a locating and clamping bar secured to an edge, usually the leading edge, in predetermined position, comprises a plate support, means to locate a plate-clamping bar thereon, register gauges adjustable on the support, and means to adjust a plate on the support whereby an edge of a first plate having been located and secured to a bar located by the support and the gauges having been set to register with the register marks on the plate, the succeeding plates can be registered to the gauges before their edges are secured to their located clamping bars. A plate clamp 89, Figs. 1 and 8, is placed in a longitudinal groove 80, Figs. 1, 2 and 6, in the plate support 10, Figs. 1, 2, 4 and 6, and located by a pin 85, being secured by rotating handles 105 of screws 102 abutting the lower clamping bar 88 to force a rib 100 into a groove 84. The first plate 11 is laid on the support and inserted between the upper and lower clamping bars 95, 88 with an edge abutting a shoulder 97. Side clamps 135 are moved along a bar 114 until plate clips 140 overlie the edges of the plate, when screws 142 are rotated to clamp the plate to the clips 140 and the clamps 135 to the bar 114. Heads 128 are turned to operate slides 112 to move the bar 114 laterally and retract the plate edge 1/16th inch from the shoulder 97. The bar 114 is so connected to the slides 112 as to be capable of swinging movement relative thereto, being pressed against studs 115 on the slides by spring- pressed plungers in blocks 118 on the ends of the slides. The plate is then secured to the clamp 85 by tightening screws 106, and the clips 140 are released. Recording assemblies comprising magnifiers 60 and transparent targets 55 carried on rods 50 are mounted on slides 45 slidable in blocks 42 screwed to cover-plates 37, which are secured by screws 38 passing through two of four holes 39 in the cover-plates to slides 36 slidable in grooves 35 in hinge-plates 30, the slides 45, 36 being locked by screws 75, 68. The assemblies are swung into operative position with the targets 55 contacting the plate, about pins 31 pivoted in base-plates 27. The targets have register marks 56 thereon. The base-plates 27 are slid along a groove 18 in a rail 17 integral with the support 10 until the targets are in approximate longitudinal alignment with the register marks on the plate, and secured by screws 25. The targets and magnifiers can further be rotated through up to 90 degrees by loosening screws 51. The assemblies are then adjusted longitudinally and laterally by screws 63, 72 operating the slides 36, 45, and if the lateral adjustment possible is insufficient, the screws 38 are removed and inserted in a different pair of the holes 39. When the register marks on the targets and plate are in accurate alignment, the slides 36, 45 are locked, the assemblies swung to inoperative position about their pivots 31, the screws 102 loosened, and the clamp 89 and plate removed. A clamp 89 for the next plate of the set is now located and secured in the groove 80, the edge of the plate inserted in the clamp and brought against the shoulder 97, and the plate manually moved as near as possible to the longitudinal position of the first plate. The plate is secured to the clips 140 and the assemblies swung to operative position. The plate is then adjusted longitudinally by turning a screw 158 to move the bar 114 longitudinally through a lever 143 pivoted to the support 10 at 149 and a link 146a pivoted to the lever 143 at 148 and to the bar 114 at 147. Lateral adjustment is performed by rotating the screws 128 operating the slides 112. When the register marks are in alignment, the plate is secured as before to the clamp 89, the clips 140 are released, the clamp 89 released, and the plate and clamp 89 removed. This process is repeated for each plate of the set.