Patent GB-814443-A (GB)
Title: Stereotype plate holding means for printing cylinders
IPC: B41F27/10
Filed: 1957-10-21
Abstract: 814,443. Printing surfaces. MIEHLEGOSS-DEXTER, Inc. Oct. 21, 1957 [Dec. 11, 1956], No. 32801/57. Class 100(2) A printing cylinder 14 having plate tensioning hooks 11, 11a, for one edge of a semi-cylindrical printing plate, e.g. 10 and hooks 20, 20a for the other edge of the plate is provided with linking pieces 30 whereby two tabloid sized plates e.g. 25, 26 may be joined together and tensioned by the hooks 11, 11a. In the embodiment shown in Fig. 3 the linking pieces, which are flush with the cylinder surface and mounted in an axial slot 31 in which arcuate filler pieces 34 are secured, have integral plate engaging hooks 30b, 30c and bottom arcuate portions 30a so that the linking pieces may slide in undercut grooves 39 formed in cover plates 36 by which they are secured in the cylinder. The links have projections 30d which co-operate with the grooves 39. Notches 40 are provided in the plate 36 so that the links 30 may be removed when full-sized plates are mounted on the cylinder. The links are biased by a spring 41 bearing against the head of a plunger 44 to tension the plate 26 in such a manner that the plate 25 can be removed whilst leaving the plate 26 undisturbed. Releasable spring detents 45 are provided for retaining the linking pieces in a position such that the projections 30d cannot accidently register with the notches 40. In alternative embodiments hooks 30b, 30c may be replaced by plate engaging pins or by a hook which engages grooves in the upper surface of the plates 25, 26 (Figs. 7 and 8, not shown), In the embodiment shown in Figs. 10 and 11 the linking pieces are biased by springs 91 in a direction such that both plates 25 and 26 are released when the main tensioning hooks 11a are released. Further the hooks 85 on the linking pieces are retractable within the cylinder surface so that no provision need be made for removing the linking pieces when a full-sized plate is to be used. To this end the hooks are biased downwardly by a leaf spring 88 so that when the linking piece is moved to the position shown in Fig. 11 the hooks enter recesses 82a formed in the filler pieces 82, the linking pieces being retained in position against the action of spring 91 by a spring detent 94. The recesses 82a act as camming surfaces for raising the hooks when the linking piece is moved to the position shown in Fig. 10. In a further embodiment (Fig. 15) the hooks 107 ar e pivoted in the linking pieces and have hubs in which are formed holes 107b, 107c in which a detent 111 of a spring urged pin 110 may be engaged to hold the hooks in retracted or raised positions. The pins 110 are operated by means of pressure on upstanding fingers 112. A compressible, telescoping, toggle link 120 is provided for biasing the linking piece circumferentially of the cylinder 14. For engaging the recessed corners of tabloid plates adjacent the linking pieces on the outside ends of a cylinder slidable bars are provided in the cylinder, held in one of two positions by spring loaded detents so that they may be held outwardly and away from engagement and full sized plates when these are used. The corners of tabloid plates adjacent the linking pieces in the centre of the axial length. of the cylinder are engaged by spring loaded stops which when depressed and rotated are held flush with the cylinder to permit use of full sized plates.