Mechanism for stopping an electrically-driven machine tool on failure of lubricant pressure

摘要

725,929. Control of motors. SENECA FALLS MACHINE CO. Dec. 4, 1953, No. 33822/53. Class 38 (3). A motor M driving a machine tool is stopped at the end of an operation of the machine following a failure of the lubricating-pressure. For this purpose, parallel-connected switches S5, S6, are placed in a holding-circut of an operating coil 20 for a main conductor S2, it being necessary for both of the switches to be opened before the circuit of the driving motor is interrupted. The switch SS is opened by means of a bellows when the pressure of the lubricant drops below a'normal value the switch S6 being dog-operated upon the completion of the machine operation in progress