GB773088A - Improvements in or relating to contour gauging device - Google Patents

Abstract

773,088. Contour gauges. SHEFFIELD CORPORATION. May 20, 1954 [May 28, 1953], No. 14813/54. Class 106 (2). A work-piece such as a turbine blade 64 is gauged for departure from theoretical dimensions by setting up the blade &c. in a support 38 angularly adjustable on two shafts 34, 36 at right angles in such a manner that the axes of the shafts intersect at a reference point W in or on the blade &c. from which all other points are measured, locating a gauge member 20 in an initial setting to obtain a gauging indication for the point W along a measuring co-ordinate such as 65, and then adjusting the blade &c. and the gauge member as by the interposition of gauge blocks 57, 61, 55, 54 to set the gauge member at the theoretical position of a second point, say 66, on the blade surface for gauging along a co-ordinate 70. Any deviation from the initial indication will show the amount of departure of the second point from its theoretical position. A blade &c. can be calibrated to take the place of an exact master blade by marking each point gauged with a scriber and recording the errors at each point. The gauge member 20 is longitudinally adjustable in a block 17 slidable on a column 16 fixed to a block 11 slidable in guides 15 on a base-plate 10. The work support 38 is carried by a horizontal shaft 36 rotatable in an arm 12 mounted on a vertical pivot 34 in the base-plate, the shaft 36 having an arm 37 for adjustment by the gauge block 61 against a stop 62. The arm 12 has a depending member 58 for adjustment by the gauge block 57 against a stop 60, and the sliding movements of the gauging member are adjusted by the gauge blocks 54, 55, 56. In use the blade &c. is clamped against a stop 45 so that the reference point W lies at the intersection of the axes of the shafts 36, 34 and gauge blocks are positioned at 56, 57, 61 to align the axes of the shaft 36 and the gauge member 20. The block 17 is lowered into contact with the block 11, a gauge block equal to the distance between the point W and the surface 67 of the mounting block 38 is inserted at 54 and the gauge 20 adjusted along its housing 19 while the work contactor 24 is in contact with the surface 67 until a given intermediate reading is obtained on a gauge, and then clamped. Different predetermined gauge blocks are then inserted at 57, 61, 56 and 54 and a block inserted at 55 to raise the gauge member to the correct height, so that the gauge member is brought opposite the second point 66. On removal of the block 54 the gauge head is moved in to contact the blade and indicates the departure from true position of the second point. For scribing, the gauge member is removed after gauging and replaced by an eccentric scribing point which is turned to scribe a circle around the point gauged. The work-piece is clamped in position by a compressed air operated finger projecting through the block 38 from a cylinder 51. The indicator of the gauge may be pneumatic, mechanical or electrical.