GB617604A - Improvements in or relating to linear dimension gauges - Google Patents

Abstract

617,604. Linear dimension gauges. STEVENS, A. H. (Sheffield Corporation). Nov. 1, 1945, No. 28996. [Class 106 (ii)] A linear-dimension gauge for checking internal or external dimensions comprises a pair of spaced carriages 23, 38 vertically adjustable simultaneously by a pair of elevating-screws 28, 37, respectively, carried by a support 11, and a carrier 19 supported on the carriages 23, 38 by a number of flexible spring blades permitting limited horizontal movement of the carrier, and a pair of gauging-fingers 14, 15 on the carrier 19 and extending upwardly therefrom. The fingers 14, 15, which are associated with an electromagnetic indicator, project through a slot in the table 12 of a casing 10 which is carried on the support 11. The screws 28, 37 are operated by a motor and belt- and-pulley arrangement. The finger 15 has a tail 46 secured on a slide 47 movable along the carrier 19 on the rotation of a screw 56 engaging a split nut within a housing 48 forming part of the slide 47. Rotation of a rod 50 moves a cam 49 to lock the split nut on the screw 56 when the finger 15 has been adjusted. The finger 14 has a tail 61, Fig. 6, secured to a holder 63 mounted at each end on the carrier 19 by spring blades 66 whereby the finger has limited yielding movement towards or away from the finger 15. In addition, the finger 14 is urged yieldingly in a predetermined direction by means comprising a stud 69, on the holder 63, arranged between two springs 70, 71 in a housing 72 secured to the carrier 19. A cover 73 with down-turned ends covers the opposite ends of the springs and can be adjusted to press either of the springs into contact with the stud 69, whereby the finger 14 is urged yieldingly either towards or away from the finger 15 according to whether the gauge is to be used for internal or external gauging. Relative movement between the carrier 19 and holder 63 of the finger 14 operates a spring-pressed plunger in a housing 87 containing an electromagnetic device whereby an indicator 16 shows the movement of the finger 14. To detect whether the carrier 19 has been displaced by a workpiece too far from its neutral position for accurate gauging, indicating lamps 89, 94 are provided which indicate correct positioning when both are lit. In addition, to avoid displacement of the carrier by a workpiece, a work-locating device is provided comprising a base slidable on the table 12 with a projection engaging the slot therein, an upright having an adjustable bracket thereon carrying a horizontally-adjustable arm from which depends a vertical bar carrying a work-engaging stud. This stud is moved to point immediately above the finger 14 and in contact with the work, and then the finger 15 is positioned.