GB696947A - Improvements in or relating to micrometer gauges - Google Patents

Abstract

696,947. Calliper gauges. STEUART, F. G. Feb. 9, 1951 [Feb. 9, 1950], No. 3370/50. Class 106 (ii). A micrometer gauge of the calliper type having an indicating dial is characterised in that the measuring heads are each provided with projecting studs which are spaced apart when the measuring heads are at zero position, whereby the studs may be used for measurements having a lower limit of the amount of the spacing at the zero setting of the heads. The gauge comprises an outer tube 17 carrying the dial face 19 and a fixed arm 13, and an inner tube 18 carrying an arm 14. Coacting gauging faces 11 and 12 are provided on the arms 13 and 14 respectively. The inner tube 18 is provided with a rack 35 carried in plugs 36 at each end of the tube, the rack 35 co-operating with a pinion 29 adapted to drive through suitable gearing two pointers 20 and 21, the gearing being so arranged that the ratio between them is 10 : 1, the pointer 21 making 10 revolutions during one revolution of the pointer 20. The inner tube 18 is cut away along part of its length along the line 38, and the outer tube is slit along part of its length and two ears 39 are formed by turning back the edges of the slit to form a housing for the gears which are mounted between plate members 23, 24, 26, 26. A toothed wheel 44 coacting with a rack 45 formed on the surface of the inner tube 18 is provided to facilitate operation of the gauge, providing a means whereby the measuring faces may be adjusted to the workpiece. Additional knife edge members 48, 47 and 46 may be provided on the coacting gauging members for purposes of inside measurement, and a third pointer 49 is then provided to indicate outside measurements which may be made with the back faces of the knife edge members, the pointer 49 being set to allow for the thickness of the two knife-edge members thus employed.