Patent GB-1438943-A (GB)
Title: Machine tool control systems
IPC: B23Q41/00
Filed: 1972-05-26
Abstract: 1438943 Automatic machine tool control MARTONAIR Ltd 29 May 1973 [26 May 1972] 25041/72 Heading G3N [Also in Division F1] Data defining an operational cycle of a machine tool is entered manually in steps into a memory, by means of a set of manually operated selection switches which are set to define a machine tool function representing a step of the cycle, between successive operations of a data storage control (MB), Fig. 1 (not shown), indicator lamps (1L) associated with each possible setting of each selection switch serving to indicate the indentity, and setting of the switch, for checking during data entry, and for information during an operational cycle. Data defining, for each step, in or out movement and feedrate of a capstan lathe turret, or its "woodpeck" movement; front, rear, and topslide movements; motor speed and direction; collet operation, and programmed delay are preset via switches mounted on a panel (Fig. 1). The pre-set data is stored, upon pressing button (MB), in that address of a random access store M.U. defined by the step number indicated at (SNI). Operation of control (SB) increases the address by unity in preparation for storage of the succeeding step. When the data is stored, indicator lamps display the stored data, for checking with switch settings. Any given step can be readdressed using control (SB) for programme correction. If a selection which would damage the machine, or indicate excessive feeds is made, unit FDC prevents storage of such data, and causes the lamps to flash until the data is reset. Machine operation. Data for each step passes from the store to output unit OS which provides control signals AV1-7 HV2-6, 8-11 to air and. hydraulic valves controlling the machine. Signals to a detector MAD enable those of machine action sensors appropriate to the particular step, and when the sensors indicate its completion, a signal to select address unit SAU enables data of the address of the succeeding step to be passed to OS, which is operative provided start signal SS has been given and no machine fault signal FDC is present. Units OS, and IS receiving data from the selection switches, comprise binary circuits whose states represent the current desired states of the lamps and machine members, or states of the switches, resp. For repetitive operation indicator PC shows the number of operation cycles, corresponding to the number of processed parts, completed. Cycle control CCS may be set for a single cycle, to allow checking of the processed part. Control of machine members, Fig. 3 (not shown). Signals AV1-7 control corresponding solenoid-operated air valves (AV1, 4-7), providing pneumatic operation of top-slide and collet, valves, "woodpecker" turret operation, and air supply from (ASU), valves (AV2, 3) providing via bi-directional boosters (B1, B2) hydraulic pressure controlling the turret cylinder, and front and rear slides, respectively, signals to hydraulic valve HV2 allowing fast feed to a desired turret position, followed by a slow feed set by one of valves H3-H6 corresponding to a programmed feedrate. Valves (HV8, 9) control fast, and programmed, feeds respectively of the front slide, with similar function of valves (HV10, 11) for the rear slide. Valve AV6 closes at power supply failure, to stop all movement. Memory unit M.U. is normally mains supplied, the mains also trickle charging battery B to which supply is electronically switched at power failure to provide a pulsed supply to memory M.U. to maintain its operation.