GB778552A - Gauging head and master fixture for multiprobe gauging apparatus - Google Patents

Abstract

778,552. Contour gauges. TANDLER, W. S. Feb. 24, 1956 [April 13, 1955], No. 5751/56. Class 106 (2). The profile e.g. of a turbine blade is gauged by means of a probe head having a plurality of probes, 30-33, 30a-33a, 30b-33b, Fig. 2, mounted on a support in a two-dimensional array, transverse and normal to the transverse, to the longitudinal direction of the probes, the probes being independently adjustable in the longitudinal direction and means being provided for adjusting the relative spacing. As shown, the probes are adjustably mounted in carriers 70-73 with respect to which they are also resiliently displaceable on contacting the workpiece and the carriers are supported on platforms 42 secured to L-shaped edging members 60, 60<SP>1</SP> in turn supported on shelves 50-50<SP>1</SP>, the edging members and the shelves being adjustably bolted to slotted standards 41, 41<SP>1</SP>. In use, the probe head is set up with reference to a master fixture 25, Fig. 7, having a number of pins 90, each corresponding to a probe, adjustably mounted in a block supported on a base 81 having an accurately machined bottom face, and accurately machined reference pins 83, 84 by means of which the block may be accurately positioned on a surface 10 with reference edges 121, 122. By means of a probe 130 following the path shown in dotted lines in Fig. 7, each pin may be accurately adjusted in space, it being locked in position by the corresponding screw 105. The pins are set up to correspond in location and contour with the desired contour. The probe head is then positioned with the edge 26 of its base along a reference line 27, Fig. 1, and the probes adjusted to engage with the pins. The head is then retracted and the part 12 under test substituted for the master fixture 25. The probe head is then moved forwardly until each probe has contacted the workpiece. On contact, a circuit is closed by each probe to mark a record sheet 35 by means of associated stylii 30<SP>1</SP>-33<SP>1</SP>. The deviation from standard is shown by the deviation of the recorded marks 36 from the line 27<SP>1</SP> corresponding to the datum 27.