Patent GB-191421027-A (GB)
Title: Improvements in Stereotype Plate Finishing and Colling Machines.
IPC: B41D5/00
Filed: 1914-10-15
Granted: 1915-10-14
Abstract: 21,027. Goss Printing Press Co., [Goss Printing Press Co.]. Oct. 15. Printing - surfaces; stereotype.-A machine for finishing curved stereotype printing- plates, and of the kind in which the plate is held in a rotatable cylindrical shell during the finishing operations, has the following special features: (1) the rotation of the shell is automatically started after the plate is locked therein; (2) the rotation of the shell automatically ceases after one revolution, and the plate is afterwards automatically released; (3) improved means for withdrawing the finished plate from the shell and placing it in a cooling - device; and (4) improved means for cooling the plate. The shell 24 mounted in bearings 25, 26 is rotated by a gear ring 66 constantly driven by a worm 67 and gearing from the machine-driving shaft 18. The gear 66 is freely mounted on the shell, but can be operatively connected to it by a pawl 75, Fig. 6, pivoted on the gear and engaging a notch 76 in the shell, or preferably, as shown, in a renewable plate 77 fixed to the shell. Normally, the pawl 75 is rocked clear of the notch every time it comes opposite tn it, by the engagement of a block 79 on the pawl with a projection 82 on a pivoted detent 80. The pawl is immediately afterwards released from the detent 80 by the engagement of a nose 83 on the pawl with the detent. The plate 29 to be treated is placed in the shell with its edges resting on longitudinal bars 27, 28, one of which 28 is in two parts to allow the passage of a plate-locking lug 30, Fig. 9, carried by a slidable rack-bar 35, Figs. 3 and 9, engaged by a segment gear 38. A spring-pressed rod 40 and an arm 43 on the gear 38 form a toggle to hold the rack 35 in either the plate locking or releasing position, and the pin 42 of the toggle carries a roller 44 adapted to be engaged by an arm 34 carried by a hand-operated sliding bar 31. When the bar 31 is pushed into the position shown in Fig. 3, the lug 30 is lifted to raise.the plate 29 into locking engagement with the shell, and simultaneously a roller 87, Fig. 6, on the bar 31 engages a projection 86 on the detent 80 and moves it clear of the pawl 75, so that the pawl engages the notch 76 and the shell is rotated. The bar 31 is held by a latch 46 engaging a notch in the bar until a cam 88 on the shell engages an arm 50 on the latch and releases the bar 31, which returns to its normal position by means of a spring 33. The return of the bar releases the detent 80, so that at the end of one revolution of the shell, the pawl 75 is again released from the notch 76. A spring-pressed detent is provided to stop the shell and hold it when at rest. A cam 89 carried by the gear 66 then engages the roller 44 and releases the plate 29. The plate 29 is accurately positioned in the shell by means of a rocking stop 51, Figs. 2 and 6, in the form of a bell-crank lever, the vertical arm of which is provided with two spring-pressed stops 62, 63, and the lower arm of which encircles a pin 57 fixed to a table 53 and carrying a spring 58 and adjustable stopnuts 59. When the plate is introduced, it rocks the stop 51 to an extent limited by the nuts 59, and after the plate is lifted by the locking-lug 30, the stop returns, so that when the plate is released, it rests upon the stops 62, 63 and is supported by them during its withdrawal from the shell. The ribs of the plate are shaved by a cutter 92, and the ends are trimmed and bevelled by rotary cutters 93 secured to a shaft 94 driven from the shaft 18. The plate 29 is withdrawn from the shell by gripper fingers 122, 123 carried by a bar 121 slidably pivoted on a pin 140 on an arm 120 fixed to a rack 107, which is constantly reciprocated by gearing 109, 113, 110 driven from the shaft 18. The finger 123 is rigid with respect to the bar 121, and the finger 122 is pivoted to the finger 123 and is held in the gripping or releasing position by a spring 129 on a rod 125 pivoted to the finger 122 and sliding through an eye in a lug 128 pivoted to a boss 126 on the arm 121. A vertically slidable stop 131, which is frictionally held in either its upper or lower position, is normally depressed by a roller 135 on the rack 107 into the path of the finger 123 so as to arrest the movement of the bar 121 and grippers and prevent engagement with the plate 29. The stop 131 is raised clear of the finger 123 by the cam 88, which is so disposed as to engage a shoulder 137 on the stop just before the shell comes to rest, so that the bar 121 can move further towards the shell to allow a projection 130 on the finger 123 to engage the stop to close the gripper on to the plate 29. The backward movement of the gripper draws the plate from the shell on rails 106 into a cooling- chamber 105. The grippers are operated to release the plate by the engagement of the projection 130 with a pivoted finger 152, Fig. 2. The bar 121 is normally held in an horizontal position by means of a bar 145 pivoted to the rack 107 and provided with an angular slot 147 engaging a pin 148 on the bar 121. The pin 148 and pivot 146 of the bar are connected by a spring 151, and the bar is normally held in the position shown by a spring 149. After the release of the grippers from the plate, the bar 145 engages a fixed pin 156, Fig. 2, and is thereby turned so that the pin 148 engages the vertical part of the slot 147 and the bar 121 is raised by the spring 151 so that it can return freely over the top of the cooling- chamber. The bar 121 is returned to the horizontal position by the engagement of a roller 127 on it with a fixed cam 157, The plate is cooled by a series of brushes 158 secured to a shaft 159, which is continuously and rapidly rotated by gearing from the shaft 18. The brushes take up water from an inclined plate 160 supplied from a pipe 161. The plate is pushed out of the cooling-chamber by a lug 165 on the gripper finger 123.