Patent GB-423678-A (GB)
Title: Ingot stripping apparatus and methods of controlling the operation of such apparatus
IPC: B22D29/04
Filed: 1933-08-09
Abstract: 423,678. Ingot-stripping apparatus. GATHMANN, E., Box 43, Carroll Station, Baltimore, U.S.A. Aug. 9, 1933, No. 22318. [Class 83 (i)] A machine for stripping ingots having some of the features described in Specification 386,828 has an electric control device, which makes the operation semi-automatic and avoids damage due to incorrect actuation, and means for applying additional pressure should the ingot stick. A truck E carrying two rows of moulds D to be stripped is engaged by a counterweighted hook 101 which may be released by raising a rail 112 by a hand lever. The hook, which is pivoted on a rack 94 and locked in raised position by a latch 118, is then moved by a reversing motor 123, with an automatic regenerative brake, to advance the truck to the stripper A. The motor is controlled by forward and reverse, handoperated, switches, the forward circuit including a switch IX, Fig. 2, opened by one of a series of projections 131 on the truck E to arrest it when a pair of moulds D is in alignment with the stripping plungers 60, 60<1>. The projection 131 also closes a switch X in the circuit of a motor 32 to rotate nuts 26 and bring screwoperated clamps 48 onto the moulds. Each screw 34 is connected to its clamp by a loose connection so arranged that as the looseness is taken up a rod 50 opens switches I and II in the circuits of the motors 32 and 123 to stop the former and prevent the latter from being operated, and closes a switch III in a relay circuit which can be completed by pressing a button and thus energize motor mechanisms 92, 92<1>, such as in Specification 363,137, [Group X], to close valves 48 in idle fluid circuits 83, 83<1> of low and high pressure pumps 65-60 to deflect the fluid to cylinders 56, 56<1>, force up plungers 60, 60<1>, and eject the castings. The relay circuit also opens a switch in the circuit of the motor 32 to prevent its operation. Should the ingot stick in the mould the resultant increase of pressure in the pipe 70 operates a device 68 to close the outlet of the pump 65, which then runs idly. The fluid from the high pressure pump 66 cannot flow back through the pump 65 and thus overcomes the resistance of the ingot. Skirts 63 on the plungers 60, 601 then open switches VII in the relay circuit of the solenoids 92, 92<1>, so that the valve 84, 841 are opened by springs 90 and the plungers 60, 601 fall, and also closes switches VII<a> in relays adapted to close the reverse circuits of the motors 32 and thus raise the clamps 48 and allow switches I, II, and III to resume their normal position and finally open switches IV and bring the motors 32 to rest. The switch IV can be short circuited by a hand switch so as to raise the clamps for the passage of a locomotive but this movement is arrested by a safety switch V. The rise of the plungers 60, 601 allows switches VIII, VIII<1> in the circuit of the motor 123 to open so that this cannot be operated until the plungers fall again. The operator then presses a button switch to short circuit the open switch IX and advance the rack 94 &c., until the projection 131 releases the switch and the advance continues uncontrolled until arrested by the next projection 131 and the whole cycle repeated. When the rack 112 reaches the end of its stroke it opens a limit switch XI in the forward circuit of the motor which is then reversed, after withdrawing the hook 101, a similar limit switch being arranged in the reverse circuit. An electrically operated valve 74 is provided to supply pressure fluid to the cylinder 56 or 56<1> as desired. The legs of each clamp 48 may be adjustable, to suit moulds of different size. The pumps 65, 68, and the device 68 may be constructed as described in Specifications 13993/12, [Class 69 (ii)], 186,474, 255,869, and 302,431, [all in Class 102 (i)].