GB783980A - Improvements in and relating to apparatus for gauging linear dimensions - Google Patents

Abstract

783,980. Turret comparators. POWER JETS (RESEARCH & DEVELOPMENT). Ltd .Tan. 10, 1956 [Jan. 11, 1955], No. 855/55. Class 106 (2). As adapted for measuring the spacing or pitch of the serrations on the roots of turbine blades, the root 48, Fig. 3, of the blade is held in a holder 45 so that the pressure surfaces of its serrations on the side to be gauged are horizontal, by a pair of fixed bevelled anvils 49 engaging the lowest serration on that side and a single movable anvil 51 engaging the lowest serration on the other side under pressure of a spring 52 which may be compressed by a lever 53 when changing workpieces. Feeler members 25 located around a central pillar 11, Fig. 2, are set at positions corresponding to the several surfaces to be gauged, in lower brackets 23 joined by a strut member 24 to an upper bracket 22, both brackets being supported by two spring strips 21 in V-formation to a bar 19. To provide for coarse adjustment the upper end of the strut 24 is secured to the bracket 22 by a screw passing through a slot 55 in the upper end block 56 of the strut while fine adjustment is secured by bowing the two strips 57 forming the strut at their centre against a spring 59 by a screw 58. The bars 19 are secured to equiangularly spaced machined flats 18 on a cylinder 15 mounted by bearings 14, 16 for rotation about the pillar 11. The cylinder 15 is rotated by a motor 31 controlled by a cam 29 to slow the motor to a lower speed whilst each of the elements 25 comes into gauging position. A leaf spring 33 with a ball contact 34 with the upper bracket 22 and an adjustable vertical stop 28 may be provided to support each gauging assembly when not in contact with the workpiece. The upper bracket 22 carries a ball 27 in contact with a tungsten carbide facing 62 on a fitting 63 clamped on the end of the indicator plunger. The indicator 42 is held in a split lug 41 at the end of a radial arm engaging by means of a split lug 38 the upper end of the pillow 11. By providing additional stations each with a workpiece holder and an indicator additional workpieces can be gauged per revolution.