GB628134A - Improvements in or relating to stereotype plate finishing machines - Google Patents

Abstract

628,134. Printing-surfaces. GOSS PRINTING PRESS CO., Ltd. Oct. 28, 1946, No. 31978. Convention date, Nov. 16, 1945. [Class 100 (ii)] In a'stereotype plate finishing machine having means to support a plate with its interior surface available for machining operations, milling means are provided which are movable axially of the plate, and at preselected points in the course of such movement are also movable automatically into and out of an operative position, so as to form a plurality of axiallyspaced recesses in the interior surface of the plate adjacent the straight edges thereof. A semi-cylindrical stereotype plate 23, Figs. 1, 6, 14, 17, is positioned in and removed from the arch 20 as described in Specification 628,133 and while so positioned its interior surface, which is provided with recesses 63 between ribs 64, is finished by a boring tool and provided with two parallel series of slots 66 adjacent its longitudinal edges by milling cutters, the slots having straight edges 67 inclined towards the edge and parti-cylindrical sides 68. The boring and milling tools are movable axially of the plate while in operation, and are carried on a common slidable frame 72, Fig. 9, reciprocated by a lead screw 102 driven by an electric motor 100, reversible, and having limit switches 105, 106. The boring tool comprises a boring head 76, carrying boring bits 77 and mounted on a heavy shaft 75 journalled in the frame 72. A plate 80A integral with the frame 72, and a plate 80 bolted thereto, each carry spring-urged rollers 81 to press the plate against the arch adjacent the boring tool. An electric motor 90 drives a shaft 91 carrying a slidably keyed pulley 93 moved axially on the shaft by a bracket 94 on the frame 72, whereby the shaft 75 is driven, in any position of the frame 72, from the pulley 93 by a belt 95<SP>1</SP>, pulley 95, shaft 96, pinion 97 and gear 98, thereby rotating the boring head. The milling cutters 113, Figs. 1, 6 and 10, are each, together with chamfer milling cutters 113a, carried on a shaft mounted in a housing 115 and driven by bevel gearing from a shaft 109, which is driven from the gear 98 by a pinion 108. The housings 115 have sleeve-like ends mounted for oscillation in the frame 72, whereby the cutters 113 are oscillatable about the shafts 109 into and out of operative position by means of depending levers 120. The levers 120 are oscillated by slide members 121 carrying cam rollers 122 moving in stationary cam tracks 135. On forward movement of the frame 72, the rollers pass along the track 130, to form four slots 66, and displace a switch 132, returning along a track 131 and through a spring-loaded star switch 133. Switches are provided to start, stop and reverse the motor 100, start and stop the motor 90, and energize signal devices such as lights to indicate that the plate is securely held in the arch, has been finished, and that the machine is ready to receive another plate.