Patent GB-135850-A (GB)
IPC: B22D17/06
Abstract: 135,850. Gullborg, J. S. May 24, 1918, [Convention date]. Casting-machines; metal-pouring; moulds; clamping moulds; castings, extracting.-In a diecasting machine, the various parts are automatically operated from a cam shaft 82, and the machine is stopped at the end of each cycle of operations. The movement for opening the mould 7, 8 is relatively slow towards the beginning and ending, when the stripping of the casting takes place, and the sprue is cut off by a sudden movement of the core-'bar 121 after the injection of the metal. Means are provided for moving the melting-pot 9 horizontally to bring the mouth 30 against the fixed portion 7 of the mould, for controlling the air-pressure supply to the feeding- passage 28, for inserting and removing lateral cores or die parts, and for raising and lowering the safety hood 170. The moving part 8 of the mould' is carried by a slide 17 actuated by an adjustable connecting-rod 26 and crank-pin 23, which is oscillated to just past each dead-centre through a rack 102, lever 96, and cams 94, thus giving the part 8 a slow movement at the start, when the article 16 is being stripped from the part 7, and again at the finish of the stroke, when the article 16 is stripped from the die part 8. This latter operation is performed by stripper pins 109 mounted on a plate 110 attached to a tube 111 having adjustable stops 117, 120 engaging a fixed bracket 113. The melting-pot 9 is supported at the front by a pin 32 on which a roller 33 runs, and at the rear by trunnions 48 on levers 47 actuated through links 164, levers 160, and a cam roller 157, so that the mouth 30 is pressed against the fixed part 7 of the mould. While in this position, metal is forced from the melting-pot feedchannel 28 into the mould by compressed air injected through a pipe 69, tap 70, and valve 71 operated through a rod 237 and levers 238, 246 by a cam on the shaft 82. The channel 28 is filled with metal while the mould is retracted, by the opening of a needle valve 29, the stem 52 of which is raised by a bell-crank lever 57' attached at its upper end to a fixed link 60. Immediately after the injection of the metal and before the opening of the mould, the sprue is cut off by the sudden movement of the pointed end 22 of the core-bar 121 into the passage 31, caused by a spring-operated lever 130 released by a catch 135 operating through a pinion 126 and rack 125 to move a sliding bracket 123 carrying the rear end of the bar. The catch 135 is mounted adjustably on a rotatable shaft 138 turned through cam-operated levers 140, 141, &c. to move the catch out of engagement with the pin 136 on the lever 130. The parts are reset by the movement of the slide 17. Laterally movable cores 185<1>, 186<1> on mould parts may be carried adjustably by cross-slides 187a operated through levers 190 and cams 191, the pivot pins 194 of the levers 190 being placed in any one of the sets of holes 195 to adjust the amount of movement of the slides 187a. The safety hood 170 is raised and lowered after each casting operation, by cords 175 and cam-operated levers 176. It carries a cam 234, Fig. 2, which operates a lever 232 to move the air-control valve 71 and keep it in the '' exhaust " position so long as the hood is raised, thus preventing accidental ejection of metal. The machine is started by shifting a handle on the shaft 198 until a spring detent on it engages with a notched sector. This turns the lever 216 into the position shown in Fig. 2, and by a cross-arm 217 raises the spring- pressed brake lever 220 and brake 222 out of engagement with the driving-pulley 92, and also through link-work 223, 224, 226, 228 operates a starting-clutch. On completion of the cycle of operations, a cam on one of the main drums 81 operates a loose segment to release the catch on the starting-handle, and the spring 229 returns the clutch-operating parts to neutral position and puts on the brake 222.