Patent GB-522801-A (GB)
Title: Machine for casting metal parts, especially the grids of accumulator plates in lead and the like
IPC: H01M4/73
Filed: 1938-12-16
Abstract: 522,801. Casting-machines ; pumps and gas pressure raising apparatus for molten metals. ETABLISSEMENTS D. DOYEN SOC. ANON. Dec. 16, 1938, No. 36728. Convention date, Dec. 17, 1937. [Class 83 (i)] [Also in Group XXVIII] Casting processes ; extracting castings ; plant.- Lead accumulator plates or other castings are made in continuous succession by pumping an exact quantity of molten metal, independent of the metal level in the crucible 36, between automatically opened and closed mould halves 5, 6. A number of pumps may fill a number of moulds from one or more crucibles. A compressed fluid exercises pumping pressure on the molten metal (but kept from contact therewith by a disc 125) and may also actuate the mouldactuating ram 15, but the molten metal may be pumped up by an injected liquid which gasifies and has no oxidizing action on the metal or a fluid actuated plunger or piston pump Figs. 9 and 10 may pump up the metal. The pump 37 is located in the metal in the crucible and has a foot valve 39 or a mechanically time-opened check valve. The pump pressure on the molten metal is automatically maintained constant notwithstanding different levels of molten metal in the crucible by means of a float 40 and counterweight 131 operating by cable a rack and pinion 130 of an exhaust valve 132, Fig. 8, or by the pinion varying the position of a stop 166 in a piston pump 150, Fig. 7, by varying its stroke. The discharge of the molten metal at 124 is above the level of the metal in the crucible 36. The crucible 36 is heated by burners or electrically and is controlled by a thermostat or pyrometer 211, Fig. 8. Opening and closing of the mould half 5 is performed by a ram 15 controlled by a distributer valve 90, 91, Fig. 5, the plug 91 of which has fluid-distribution bores and is turned by a shaft 22 which shaft also carries cams 52 and 145 operating inlet valve 51 and exhaust valve 77. In operation Fig. 3 fluid pressure from a reservoir passes through a hand valve 29 to the distributer valve 90, 91 which supplies pressure moving the piston 101 to the right to close and hold the mould half 5 against the other half 6. Rotation of the shaft 22 Fig. 6 and cam 52 opens valve 51 so that a quantity of gas .determined by the amount of opening of the valves 51, 77, hand valve 55, and float level and rack-operated valve 132 enters the pump 37 and discharges metal up the spout 38 and into the mould. After this casting, valve 51 closes, exhaust valve 77 opens, the pressure in 53 and pump 37 falls to atmosphere. ball valve 129 opens to allow a fresh quantity of metal to enter the pump 37 while piston 101 is moved to the left to open the mould with end cushioning, the cast plate being ejected by sliding pins 9, Fig. 1, coming against a fixed stop plate 10. The pump for the molten metal may be actuated by a separate pump, the piston 150 of which is operated by pressure fluid supplied through the same inlet valve 51, to raise up the piston 150, Fig. 7, of an intermediate pump against a spring 165 to push the fluid pressure gas above it on to the pump 37. The stroke of this piston 150 is initially adjusted by the handwheel 171, and adjusted by the level of a float 40 operating a rack and pinion 162 containing the screw-threaded rod of the piston, so that the initial height of the piston 150 is regulated to give the required travel and so the required discharge. In Fig. 8 the metal may be delivered by evaporation of a liquid injected into the barrel of the pump 37 in which an adjustable eccentric 180 replaces the cam 52 of Fig. 6 and operates a pump to deliver a fixed quantity of evaporatable liquid into the barrel 37 the quantity delivered being regulated by a valve 132 operated by rack and pinion from a float 40. In Fig. 9 the pressure fluid actuates the piston 229 of an auxiliary pump 226, until a cross member 238 on the piston rod abuts against stroke regulating nuts 240, a plunger 219 delivering the fused metal. The stroke regulation in accordance with the level of the molten metal is the same as in Fig. 10 in which the float actuates through a chain 269 and gears 264, 265, moving the clamp 238 up or down so setting the initial position of the piston 230, so regulating its possible stroke. In Fig. 10 the piston 219 delivers the metal. The main fluid pressure exhausts through a filter or dust collector before passing to atmosphere or to the required compressor. The ejected castings drop on a deflector 67 which guides them to a conveyor belt 68.