GB633130A - Improvements in or relating to taper control indicator - Google Patents

Abstract

633,130. Grinding and polishing. BROWN & SHARPE MFG. CO. July 30, 1946, No. 22660. Convention date, Aug. 7, 1945. [Class 60] [Also in Group XXXVIII] The angular play of a swivel support in a machine tool, e.g. a cylindrical grinding machine for operating on tapered work, is measured by two gauging devices spaced apart along the length of the swivel support, each gauge including an element, e.g. an electric strain sensitive resistor, responsive to movement of the associated portion of the swivel support, and the responses of the two gauges being combined to give a net indication of the angular displacement. As shown, the swivel table 10, which supports in known manner cylindrical work to be ground, swivels at 114 on a reciprocable table 12 and is secured in adjustable angular relationship thereto by a screw and nut 116, 120. The gauging devices each comprise a housing 14, 16 clamped in a transversely adjustable position on table 12. A sleeve 26 is mounted for limited longitudinal movement, e.g. twentythousandths of an inch, in the housing and carries an adjustably clamped plunger 28 the outer end of which contacts a spherical bearing 34 on the swivel table 10. Angular movement of the swivel table 10 thus causes opposite longitudinal movement of the sleeves 26 which through sleeves 52 rock cantilevers 54, 94 carrying strain sensitive resistors 58, 60 and 98, 100 respectively, on their opposite faces. The four strain-resistors are arranged in an A.C. bridge, Fig. 4, so that the strains produced by movement of the opposite ends of the swivel table operate differentially to produce a net out-of-balance voltage, a portion of which is taken off at R3, amplified, and applied over transformer T3,1 and rectifier ring RX to a centre zero meter M where the out-of-balance voltage is compared in magnitude and phase sense with a voltage derived through the transformer T2 from the oscillator supplying the bridge. Sensitivity of the meter is varied by the potentiometer R3 which is adjusted in accordance with the ratio of the lengths of work in question to the full length of the table 10. This ratio is indicated on a dial, Fig. 3 (not shown). Zeroizing of the bridge is effected by a potentiometer R2. For setting up the apparatus knobs 46, Fig. 1, are provided, which, when depressed against biassing springs 50, move the sleeves 26 to their central positions. In addition the cantilever 94 is angularly adjustable about pivot 102 by means of a screw 110 and co-operating spring-biassed stop 112.