GB616970A - Improvements relating to means for tracing or checking the contours of irregular profiles - Google Patents

Abstract

616,970. Surface and outline gauges. POWER JETS (RESEARCH & DEVELOPMENT), Ltd., GRAY, S., and BIRCH, A. J. Oct. 19, 1945, No. 27607. [Class 106 (ii)] [Also in Group XX] In apparatus for indicating or recording the profile of a workpiece such as a turbine blade 2, the follower 15 is of circular cross-section such as a roller or wheel, mounted rigidly on a member 10 adapted for transverse sliding movement on a member 6 by means of balls 8 engaging grooves in the two members, and the repeater 17, also rigidly mounted on the member 10, comprises a plate having a hole 18 therein of the same size as the follower 15. The member 6 is also mounted on balls 5 for sliding movement on a base 3 in a direction transverse to the direction of movement of the member 10 whereby the follower 15 can be traversed around the blade 2 and the repeater 17 will follow such movement. The follower 15 can be adjusted vertically by micrometer means instead of the arrangement shown. An optical projection apparatus 19 projects a beam of light through the hole 18 on to a screen 20 on which may be mounted some light-sensitive material. Adjustable straight edges 21 forming datum slides may be provided. The screen 20 can be immediately beneath the hole 18 when no enlargement is necessary. In a modification the optical apparatus is replaced by a scribing-apparatus, the scriber comprising a loose cylindrical disc having a lower cylindrical sharp edge bearing on a coated plate, a vertical arm attached to the arm 16 being spring-pressed downwardly on the scriber through the medium of a ball interposed between this arm and the scriber. Reference has been directed by the Comptroller to Specification 586,071.