Patent GB-811925-A (GB)
Title: Apparatus for casting stereotype printing plates
IPC: B41D3/04
Filed: 1956-09-18
Abstract: 811,925. Stereotype plate casting apparatus. MIEHLE-GOSS-DEXTER. Inc. Sept. 18, 1956 [March 26, 1956], No. 28505/56. Class 100(2) Casting apparatus ing plate comprises a stationary upright mould box 15 having a concave surface, a plunger core 16 (Figs. 1 and 3) having a convex surface and movable between open and closed position relative to box 15, and a head ring 40 rigid with the plunger for stereotype print- and adapted to close the lower end of the mould space, the ring 40 being so formed as to define a recess including an inclined wall such as will result in the moulding of a bevelled edge on the lower end of the plate. The plunger 16 is supported on spaced frame members 18 having rails 18a on which rim guide wheels 66 journalled in bearings 64 on brackets 60 which are fixed on opposite sides of the plunger 16 to sliding bar brackets 34 by bolts 61. The brackets 34 are bolted to the plunger 16 and carry a pair of sliding bars 35 which may be moved radially to seal the frontedges of the mould when the plunger is in casting position. The brackets 60 include depending brackets 68 which are pivotally connected by pins 72 to links 70. The links 70 are keyed to a rock-shaft 69. The shaft 69 is rotated by suitable means such as an air cylinder 100, and is fixed in bearings in the side frames 18 so that it may be rotated anti-clockwise to position the plunger 16 in the mould box 16. As shown in Fig. 7 the position of the shaft 69 is such that over the last part of movement of the plunger into the mould box the plunger remains substantially vertical and is moved substantially horizontally along the rails 18a. This movement occurs, as represented in Fig. 7 when the shaft 69 moves through the angle 20. Such movement is rendered necessary by the provision of the head ring 40, Fig. 4, having cooling fins 53, on the plunger 16. The head ring is connected rigidly to the plunger by bolts 41 and has a flange 42 adapted to engage the matrix 20 and press it against a bead 46 on the concave surface of the mould box 15. A ring 47 having a surface 48 is connected to the mould box 15 and is engaged by a shoulder 49 or the head ring 40. The ring 40 is provided with an inclined recess 51 so that plates may be cast with a bevelled edge. On account of the bevelled edge being provided on the cast plates, the latter must be removed from the plunger in a dirction making an acute angle less than the angle a (Fig. 4) with the longitudinal axis of the plunger. Ribs as provided on the underside of the cast having the configuration shown at 95 and the angle of removal of the plate therefrom must be between a and #. To this end plate-strippers 80 are provided with ears 84 having slots 85 engaged by pins 86 on the sliding bar brackets 34, the strippers 80 having a depending leg 88 adapted to engage abutment rollers 90 On brackets 89 fixed to the side frames 18. The arrangement is such that the strippers 80 engage the plate at the point where the pins 86 are in the inclined portions 85c of the slots 85. As shown in Fig. 6 the matrix 20 is initially held by a matrix setting leaf 25 disposed on each side of the surface 21 of the mould box 15. The leaf is pivoted on a vertical pin 26 and is biased outwardly to the position shown by torsion springs 28. As the plunger 16 is moved into the mould box 15 blocks 37 bolted to the bracket 34 engage the leaves 25 and shift them inwardly so that the matrix 20 is moved back against the surface 21 where it is retained by suction against the suction parts 24. The interior of the plunger 16 and mould box 15 may maintain fluid passages for the circulation of liquid coolants. Operation of the air cylinder 100 may be power assisted as described in Specification 811,926.