GB596207A - Improvements in or relating to apparatus for effecting selected cycles of movements particularly of the work tables or the like of machine tools - Google Patents

Abstract

596,207. Controlling motors; actuating switches. VICTORIA MACHINE TOOL CO., Ltd., SELBY, J., and KRIEGER, G. O. I. Oct. 16, 1945, No. 27035. [Classes 38(iii) and 38(v)] Movement of a control element to any one of a number of positions and then back again to normal establishes a selected one of a number of electric circuits and breaks any such circuit established in response to a preceding reciprocation. The Figures show the control plunger 7 movable to different positions by dogs 1-5 on the reciprocating table 6 of a machine tool, thereby operating switches 1S-5S to control the motion of the table which can be driven at different speeds by two motors, as in Specification 596,147, [Group XXIV]. The plunger, which is biassed upwards by the spring-pressed lever 10 pivoted at 47 on the front cover of a housing having a groove 45 in which the plunger slides, has a reduced portion carrying the channelsectioned slider which is separately biassed upwards by the spring-pressed lever 13 pivoted at 46. The slider 9 carries switchoperating studs 15 and 16. Downward movement of the plunger and slider closes switch 5S to prepare the circuit of the contactor coil 5w controlling feed movement to the left, or one of switches 3S, 2S, 1S, to prepare the circuit of one of the contactor coils 3w, 2w, 1w, controlling quick movement to the right, quick movement to the left and feed movement to the right respectively, according to whether the plunger is depressed by a small amount by the inclined surface 40 of dog 5 or by progressively greater amounts by one of dogs 3, 2, 1. The plunger, when released, rises to normal, and, by stud 19, closes switch N to energise the selected contactor, the slider 9 being held by the spring- pressed pivoted latch 17. The contactor closes the associated one of contacts 1C-5C to complete a maintaining circuit through closed switch M. When next depressed by another dog, the plunger 7 immediately opens switch N and also releases slider 9 by the withdrawal of latch 17 by its engagement with the inclined surface of cam element 25 pivoted on an arm 26 rigid with the plunger; the energised contactor however maintains itself. The slider 9 prepares the circuit of another contactor and is again latched. On return of the plunger a spring-pressed pin 20 thereon is pushed out by the inclined surface of a pivoted cam element 21 to open switch M and so open the first contactor; closure of switch N then closes the second contactor. During upward movement of slider 9 the latch 17 deflects cam element 25 by turning it about its pivot against spring pressure. Similarly during downward movement of the plunger the pin 20 deflects cam element 21, instead of opening switch M. Each dog is pivoted at 8 on a bracket 35 so that it can be deflected when the back part 42 engages the head of plunger 7. Each bracket 35 is slidable along the table 6 and can be clamped in position in the usual way by screw 36 in a nut slidable along a T-shaped groove in the table. The cam 4 can move plunger 7 only far enough to open switch N and stop the table.