GB762779A - Improvements in contour or profile gauges - Google Patents

Abstract

762,779. Profile gauges. WATSON, MANASTY & CO., Ltd., and SIBTHORP, A. N. Jan. 12, 1955 [Jan. 13, 1954], No. 973/54. Class 106 (2). A profile gauge comprises a plurality of flat parallel laminae 10 adapted to slide over one another and to be brought into contact at one end 15 with the surface to be gauged, together with means for optically projecting images of like reference points 20 on. the edges of the laminae 10 on to a screen 41 to provide a reproduction of the profile of the surface engaged by the ends 15 of the laminae. Each lamina, Fig. 4,.is bevelled at 14 and has a short contacting surface 15, being provided at the other end and on one side with a laterally projecting ear 16. The distance between the contacting surface 15 and the surface 17 is constant for every lamina. The surface 18 is polished to reflect light. The laminae, which are mounted on a bar 19 passing through slots 13, slide parallel to themselves on the bar, and are held in place by stops 21, 22. Each set of laminae can be moved into contact with the surface to be gauged by means of an electromagnet, one beneath each set. Where the surface to be gauged is concave the set is moved from a position of rest against an arcuate stop 33, 34, the radius of curvature of which is less than that of the surface to be gauged, thus ensuring that the central laminae register first with the concave surface, at the same time as the corresponding laminae of the other set, eliminating distortion of the article 24 under test. A work-table 36, mounted in front of a cabinet 35, supports the article under test. Two sets of laminae 11, 12 move inwardly from opposite sides of the worktable to engage opposite faces of the article. Two sources of light (not shown) each direct light through a condenser (not shown) on to one group of laminae to illuminate the surfaces 18 whose edges 20 are reference points. Two lenses 39 each receive reflected light via prisms 38 and the images of the profiles are reflected from a mirror 42 on to a screen 41. The Specification describes other methods of moving the laminae and other optical systems for the reproduction of the profile of the surface.