Patent GB-653706-A (GB)
Title: A machine tool of the single spindle lathe type
IPC: B23B7/14
Filed: 1948-08-06
Abstract: 653,706. Control of several motors. WARNER & SWASEY CO. Aug. 6, 1948, No. 20865. Convention date, Aug. 22, 1947. [Class 38(iii)] [Also in Groups XXII and XXIV]  Three electric motors 72, 181, 228 for rotating the work spindle and providing the rapid forward and reverse traverse, working feed, and indexing of the tool carrier of a lathe (see Group XXII), are arranged in a circuit, as shown in Fig. 52, which is controlled by switches operated by cam drums in the machine. The motor 72 is arranged to rotate the work spindle through change-speed gearing controlled by four fluid-operated clutches under the control of three solenoid-operated valves. The rotor shaft of the reversible highspeed motor 181 is driven from the work spindle through further change-speed gearing controlled by three magnetic clutches, this shaft being arranged to drive through gearing the means for traversing the tool carrier. When the tool carrier is to be fed at slow speed from the motor 72, the motor 181 is de-energized and its rotor rotates idly; a magnetic brake on the shaft of the motor 181 is de-energized whenever the carrier is in movement. The control of the motors is by (a) a control turret 68, Fig. 36, provided on the shaft of the tool carrier so as to reciprocate and index therewith, (b) a control drum 270, Fig. 23, driven through gearing from the motor 72, and (c) a control drum 280, Fig. 36, on a ring member 217 which indexes the tool carrier. The turret 68 is provided on each face, which corresponds to an indexing face of the tool turret, with a. number of axial slots 289 for the reception of dogs 263 adapted to be placed for co-operation with appropriate switches ILS for de-energizing the motor 181 at the desired point in the fast forward traverse of the carrier so that the latter is then operated from the motor 72 at a selected feed-rate and the work spindle is' rotated at a selected speed. The desired spindle speed is selected by positioning the dogs 263 on the turret 68 so that, during the traverse of the carrier, they actuate appropriate switches TLS which thereby energize the necessary combination of solenoid valves according to the speed desired. The selected feed rate of the carrier is similarly effected by a dog 263 operating a switch TLS so as to energize the appropriate magnetic clutch. The cam drum 270 co-operates with switches CDLS for (a) energizing the motor 181 in reverse either immediately at the end of the working movement of the carrier or after a short delay, and (b) de-energizing the motor 181 and energizing the indexing motor 228 at the end of the return movement of the carrier. The control drum 280 is provided with a number of sets of circumferentially-spaced openings 281 for the reception of dogs 282 for actuating switches ILS for de-energizing the motor 228 after one or more indexing movements of the carrier and energizing the motor 181 for forward movement of the latter at high speed. The circuit of the electric motors 72, 181, 228 includes also a coolant pump motor 333, Fig. 52, control transformer C7, rectifier R, and rectifier transformer R.T. The secondary of the control transformer provides the A.C. control circuit which includes the various control switches, and the secondary of the rectifier transformer provides a D.C. control circuit in which are disposed the magnetic brakes for the motors 181, 228 and the magnetic clutches controlling the change-speed gearing operating the traverse of the carrier.