GB602822A - Improvements in speed controlling mechanism for machine tools - Google Patents

Abstract

602,822. Lathes. JONES & LAMSON MACHINE CO. Sept. 24, 1945, No. 24763. Convention date, Sept. 26, 1944. [Class 83 (iii)] [Also in Group XXIV] A speed control mechanism for machine tools comprises a number of speed change devices electrically actuated by sets of selective switches and a master switch for each set, means being provided for operating the master switches serially. As applied to a turret lathe, the cutting speed of each tool is pre-selected and is operative automatically on the presentation of each tool to the work, the feed of the crossslide being controlled by similar gear-change mechanism. The feed-shaft 18, Fig. 1, drives the turret and cross-slide through similar gearboxes 17 and 24 operated electrically from the turret lay-shaft 8 in conjunction with the master-switch box 9. The lay-shaft 8 carries an eccentric 30, Fig. 4, which, on being rotated by the turret, successively contacts masterswitches, such as 31a, whereby the electrical circuit for the particular tooling operation is closed, causing solenoids to move gear-shifting levers, shown in Fig. 5, according to an electrical pre-selector box. The levers 80 and 90 are each shiftable in this embodiment to three positions giving a selection of nine speeds on the output shaft 70. The electrical control is illustrated in Fig. 11, wherein a spring-loaded contact push-button 105, on being depressed, displaces a bus-bar 102 against spring pressure at 103, the taper nose 108 of the stem engaging and passing through a slot in the bus-bar which regains its normal lateral position by virtue of a notch in the stem, whereby the push-button is locked in its depressed position. The stem is also brought into contact with a stationary bus-bar 115, the two bus-bars being connected to the solenoid relays. The displacement of the bus-bar 102 also releases any other speedcontrolling button which may have been previously selected. Nine shiftable bus-bars, each with six push-buttons contacting six stationary bus-bars, thus provide nine selective speeds for each of six successive tooling operations. A similar arrangement providing nine feed and withdrawal speeds to the cross-slide is provided, all controls being initiated from a single control panel on which a lighting system indicates the cutting speed being operated. The masterswitches controlling the cross-slide feed are operated from the lay-shaft 8, Fig. 13, which is grooved to receive slidably adjustable contact members 34, the pegs 33 being inserted as required to feed or reverse the movement of the cross-slide.