Patent GB-1127286-A (GB)
Title: Improvements in and relating to machine tools
Inventor: ALLEN DILLIS VICTOR
IPC: G05B19/12
Filed: 1966-08-02
Abstract: 1,127,286. Programmed control of machine tools. INTERNATIONAL BUSINESS MACHINES CORP. Oct.12 1966 [Aug.2, 1966], No.34526/65. Heading G3N. [Also in Division B3] A production line comprises a plurality of machine tools, means for moving a plurality of work-holders along the line past the tools, a digital programme store for each work-holder storing data of an operating programme to be followed by each tool, means for stopping a workholder when adjacent to a tool and means on the tool for reading the applicable programme data and operating the tool accordingly. As shown, Fig. 2, work-holders 16, 17 are traversed along a conveyer 12 by a lead-screw 25, driven by an electric motor, and positioned facing machine tools M1, M2, M3. The carriages 10, 11, 27 of the machine tools are mounted for reciprocating motion, towards and away from the conveyer, on stationary base members 21-23 by piston and cylinder arrangements, Fig. 11 (not shown). Movement of the carriage towards the conveyer causes locating heads 41, 42, 60, which are uniquely situated for each machine,to engage plungers on programme plates 61 on the workholders. The locating heads comprise a plurality of reciprocating plungers which actuate switches in a machine tool control circuit. It is stated that the plates and associated plungers can be replaced by magnetic spots on sensitive plates or by punched cards. The programme plates are releasably mounted and are constructed of hard plastic. A plunger is positionable either in a withdrawn or extended binary representation being formed with an annular shoulder which passes a resilient annular projection in a bore in the plate when depressed by a keyboard coding device. The machine tool control circuit, Fig. 7, is responsive to the selective closure of switches forming assemblies FD1-FD3 by the reciprocating plungers. The depth of feed of a drilling machine in inch units is controlled by switches 127-130 of assembly FD1 which selectively energize relays 40 CR-43 CR, maintained through contacts 40 CR1- 43 CR1, to set up a binary to decimal de-coder 123 having an output on lines 140-149 which is applied to a stepping switch 152. Stepping switches 154, 155, responsive to assemblies FD2-FD3 are provided for the tenths and hundredth of an inch displacements. Wipers 160, 166, 167 of the stepping switches are driven by counters 161 geared to a slide feed motor 126 advance a drilling spindle slide towards a workpiece. When the energized contacts of the stepping switches are reached relays WA1, WA2, WA3 are sequentially energized and initiate braking of the slide motor 126. The drilling slide is then retracted and actuation of a limit switch, not shown, causes withdrawal of the machine carriage from the workpiece. The slide motor speed is reduced at a predetermined position by a similar system responsive to the actuation of switches 185-188 by the reciprocating plungers. The actual position being determined by a counter 205 geared to the slide motor 126. The provision of storage relays 40 CR- 43 CR, 50 CK - 53 CR, enables repetitive operation on a succession of workpieces presented to the machine tool of which only the lead work-holder is programmed. The storage relays are cleared by a leadwork-holder of a further succession of workpieces by the energization of relays RR, 2RR. The drilling spindle speed is controlled, in steps, through a storage arrangement similar to that for tool slide positioning.