Patent GB-590025-A (GB)
Title: Improvements in stereotype plate casting machines
IPC: B41D3/00
Filed: 1945-04-09
Abstract: 590,025. Stereotype casting-machines. WOOD NEWSPAPER MACHINERY CORPORATION. April 9, 1945, No. 8752. Convention date, Dec. 2, 1944. [Class 100 (ii)] A machine for casting flat or curved stereotype plates comprises a vertical core and a casting-box, which between them provide a vertical mould-space, a melting-pot below the bottom of the mould-space, a conduit connecting the pot with the bottom of the mould-space, and a valve in the conduit adjacent the bottom of the mould-space. Figs. 1 and 2 show a manually-operated machine in which a mouldspace formed between a cylindrical core 10 and an arcuate casting-box 11 communicates by an arcuate.passage 46 with a manifold 44 connected by a conduit to the discharge spout 43 of a melting-pot 38. An arcuate slide valve 47 , reciprocated vertically in the passage 46 by an arm 50 rocked about a pivot 51 by a rod 54 and a crank 55 driven from a motor 60 by a worm 58 and wheel 57, closes the passage after a casting operation, whereupon surplus metal returns to the pot; a vent line 73 in the valve communicates with the manifold 44 when the valve is closed, to prevent formation of a vacuum. The casting-box 11 is moved horizontally away from the core by means of a hand lever 28 after each casting operation, and the core is then rotated through 180 degrees by a power-driven bevel gear 21 during which movement rotary saws 31, 32 trim off the top and bottom tails. The valve 47 pushes the metal up into the mould-space, the top of which is closed whereby the air in the space is compressed so as to increase the pressure on the metal and provide a more close-grained cast; escape valves regulate the air pressure. The metal is pumped from the pot 38 by a plunger 39 working in a cylinder 41 having inlets 42, the plunger being actuated by a handlever 63 pivoted at 64 and provided with a disengageable latch 67 normally engaging a stop 66.- A cam 69 on the shaft 64 closes a switch 70 at the end of the down stroke of the lever 63, to start the motor 60, a cam 74 on the shaft 56 then releases a self-closing switch 76 to keep the motor running until the valve is closed, whereupon the cam operates the switch to cut off the motor which is stopped by a magnetic brake, and the motor is operated to return the valve to normal position by closing a switch 80 actuated on movement of the lever 28 to retract the casting-box 11. The quantity of metal delivered may be varied by turning a rod 82 to adjust a stop 88 limiting the stroke of the lever 63, the switch 70 being simultaneously moved so that the valve starts moving at the proper time. In the automatic machine shown in Figs. 7 and 8, a core 91 is rotatable about a conduit 93a connected to a melting-pot 100, and the metal is pumped into a cavity between the base of the core and a ring 95 secured thereto and so into a mould-space between the core and a casting- box 92. A piston valve 106 actuated by levers 108, 111 from a cam 113 on a shaft 115 closes the inlet to the cavity, an extension 106a at one side of the piston maintaining the inlet to the cavity at the other side of the core closed at all times. A vent hole through the piston valve 106 communicates with the atmosphere through ducts in adjacent parts. A pump-plunger 98 in the pot 100 is reciprocated from a bell-crank 128 .rocked by levers 129, 130 from a cam 133 on the shaft 115, the stroke of the plunger being varied to vary the amount of metal delivered, by adjustment of a pin 135 in a slot 136. The shaft 115 is rotated from a motor 117 through gearing 118-124. The top and bottom tails T, T' of the cast plate C are cut off by saws and the bottom tail is ejected by fingers 147 extending from the box 92 and engaging lugs 148 on ejectors 149. Specifications 12850/03, 4300/06 8606/07, [all in Class 100], and 314,487, [Class 100 (ii), are referred to.