GB575031A - Improvements in or relating to scribing or surface gauges, test indicator stands andbases, and the like - Google Patents

Abstract

575,031. Scribing blocks, surfacegauges &c. TURNER, A. Dec. 24, 1943, No. 21633. [Class 61 (ii)] [Also in Group XIX] Relates to a supporting column for scribers or surface gauges, test indicator stands and bases &c., fitted with a micro-adjustment for axial movement in a guideway and means for preventing rotation and transverse play therein. The column 6 is located in the hardened cylindrical core 3 of a guide 2 by hard steel balls 7 held under elastic compression between the bore and a hardened cylindrical surface 8 on the column. The balls 7 are held in cages in slots having hardened cheeks 12 lying, in planes parallel to the diametral planes through the balls and the column, axial movement but not rotary movement or shake of the column being thereby permitted. For a column of one inch diameter, the radial dimension of the annular space into which the balls are pressed is made less than the ball diameter by an amount of the order of one-and-a-half to two- and-a-half thousandths of an inch. Alternatively, the column and guide may be grooved for the balls, so as to prevent rotation of the column. A fine-pitched adjusting-screw 20 having a skirt 22 to exclude dirt effects the final adjustment of the column 6 through a lever 16, a spring 24 maintaining contact between screw and lever. A universal mounting slidably and rotatably mounted on a column has a friction clutch 29 with a movable member 30 supporting a rod 31 which receives the appliance to be supported. The clamping bolt 32 for the clutch is slidably keyed to the fixed member 29 to prevent rotation of the bolt when the nut 35 is tightened-up, and a compression spring 37 holds the clutch faces in contact when the nut is loosened.