GB1386173A - Sensing head for automatic multi-dimensional measurement of specimen - Google Patents

Abstract

1386173 Co-ordinate measuring machine CARL ZEISS JENA VEB 31 May 1972 25436/72 Heading GIM A sensing head 1, Fig.1, to be mounted on the carrier of a machine movable in three co-ordinates, comprises a housing part 4 provided with trunnions 2, 2' carrying a gimbal ring 5 and an outer tube 6 tiltable about trunnions 3, 3', Fig. 3 ao that the suspended system may tilt about co-ordinate axes x and y respectively. The tube 6 rotatably supports an inner tube 8 on ball bearings 7 and 8 carries rollers 9 for guiding a sleeve 10 and sensor 15 along a z axis. The parts 4 and 5 carry sensors 13, 14; 11, 12 attached to a frame 16 on the tube 8 which sensors maybe locked in mid position by stop levers 17-20. Disengagement of the tilting system in one of the co-ordinate directions is effected by lifting magnets 21-24 connected to slides 25-28. For example, operation of magnet 22 releases the stop lever 18, lifts the gear 26 which is fixed to a joint 30 between springs 35, 36 in a cage 48, and lifts an element 49 fast with the sleeve 10, so that sensor 15 within the sleeve is slid up or down along the z axis. Other magnets are arranged to move the sensors about their axes 2, 2'; 3, 3' or rotate the frame 16 on the tube 8 about the axis z. Rotation of the tilting system about any of the three co-ordinate axes is transmitted to one of the transducers 50-53 through parts such as 54, 55, Fig.3, transforming the amount of movement into electrical values. The weight of the sleeve 10 is balanced by an equalizer 58 and the frame 16 carrying the sensors 11-14 may be inverted. In operation the head is mounted in a carrier of the measuring machine which is displaceable along three co-ordinate axes by hand or automatically. One of the magnets is caused to move out or tilt out a sensor which is then moved into contact with the body to be measured. As advance of the machine continues the sensor is moved back to a mid position by contact with the surface of the specimen and in so doing causes the transducers to reduce the velocity of the sensing head until the approach to mid position and then produce control signals which correspond to the measured value. These values may then be fed to display or calculating machines.