GB1145731A - Work-piece positioning apparatus - Google Patents

Abstract

1,145,731. Machine tool details. MOORE REED (INDUSTRIAL) Ltd. 10 Jan., 1966 [8 Jan., 1965; 16 March, 1965], Nos. 1042/65 and 11115/65. Headings B3B and B3C. A device for centring a component 1, Fig. 1, in a lathe or drilling machine, comprises a lever 3, pivoted about a pivot 4<SP>1</SP>, on a base 11, by a screw and nut 5<SP>1</SP>, 6<SP>1</SP>, and a lever 2 carrying the component, and pivoted about a pivot 4 on lever 3 by a second screw and nut 5, 6, the screws being rotated by reversible step motors 10, 10<SP>1</SP>. Base 11 may be stationary or rotary, and nuts 6, 6<SP>1</SP> are connected to lever 2 and base 11 respectively, by pin and slot arrangements 21-22, 21<SP>1</SP>-22<SP>1</SP>, to prevent backlash. The device may be adapted for automatic centring by using at least one sensor. The levers 2, 3 may be clamped relative to the base after adjustment, by a magnetic coil in the levers. When using a single sensor, the latter is fixed, and the centring device is rotated, or vice versa. Signals are taken from the sensor at each of a plurality of angular positions e.g. X, X<SP>1</SP>, Y, Y<SP>1</SP>, Fig. 1, and if a component has an index mark A which is to be brought into coincidence with the reference position B, then the components must be moved towards Y and X<SP>1</SP>. Signals from the sensor are taken via line 31, Fig. 2 to AND gates 32, 32<SP>1</SP>, and to Y, Y<SP>1</SP> logic circuits 33. Gate 32 passes a sensor signal to line 34 only when it receives an X reading signal from line 35, and gate 32<SP>1</SP> similarly passes the sensor signal to a line 34<SP>1</SP> only when it receives an X<SP>1</SP> reading signal from line 35<SP>1</SP>. Lines 34, 31<SP>1</SP> pass to X and X<SP>1</SP> stores 36, 36<SP>1</SP>, whose outputs pass to a comparator 37. If the difference in comparator 37 exceeds a predetermined amount, a signal is fed to a pulse unit 38 which feeds pulses to a step motor logic unit 40, together with a directioncontrolling signal via line 39 or 39<SP>1</SP>, and unit 40 controls the step motor 10<SP>1</SP>. A similar circuit is provided for positions Y, Y<SP>1</SP>, and four stores are provided for X, X<SP>1</SP>, Y, Y<SP>2</SP> signals, or two stores, one common to X, Y, signals, and one common to X<SP>1</SP>, Y<SP>1</SP> signals, are provided, which stores are shared on a time basis, and two revolutions of the centring device are necessary. The comparator pulse unit, and step motor logic unit can be similarly shared on a time basis, and the logic units may be mounted in a single control unit connected to the rotatable centring device through slip rings.