GB813075A - Improvements in dial indicator gage - Google Patents

Abstract

813,075. Dial gauges. STANDARD GAGE GO. Inc. Feb. 11, 1957 [Feb. 10, 1956], No. 4598/57. Class 106 (2). A dial gauge comprises a housing 10, primary and secondary levers 16, 34, pivotally mounted in the housing, each overlying the other at one end a contact member 20 on the primary lever' 16 and projecting outside the housing, a dial indicating unit 43 mounted on the housing, a shaft 52 for operating the pointer 53, the free end 34<SP>1</SP> of the lever 34 engaging a helical surface 57 on the shaft 52, means 27, 36; 28, 38 interconnecting the levers 16, 34 for causing the secondary lever 34 to move in the same direction for two directions of movement of the contact member 20 and resilient means 40 acting on lever 34 for holding all the parts in rest position. Lever 16 is pivoted at 13 and lever 34 at 31. Pins 27, 28 engage surfaces 36, 38 respectively on lever 16, these surfaces being aligned on the central line of lever 16. Thus operation of the contact member 20 in either direction causes movement of lever 34 clockwise as viewed in Fig. 3. Furthermore, the positions of pins 27, 28 are such that the transmission ratio between the two levers is the same for either direction of motion of member 20. The action of end 341 of the lever 34 on surface 57 is resisted by a hair-spring 54, thus eliminating backlash between the pointer shaft 52 and the lever 34. The contact member 20 has a portion 19 having a serrated edge 18 which mates with a similar serrated edge 17 on lever 16, Fig. 4. The serrations are held together by a spring 21 and so the member 20 can be turned angularly with respect to the lever 16 by disengaging the serrations. Alternatively a longer or shorter member 20 may be placed in position to give a different amplification. Figs. 6, 7, 8 (not shown), describe the application of the instrument to measuring the distance of a workpiece face from a machine shaft.