GB646992A - Improvements in or relating to internal linear-dimension gauges - Google Patents

Abstract

646,992. Optical gauging apparatus. EBAUCHES SOC. ANON. Nov. 17, 1947, No. 30464. Convention date, June 1, 1944. [Class 106 (ii)] An material linear dimension gauge having, in a head secured to a handle, a yieldablymounted feeler associated with an indicating device is characterized in that the indicating device comprises a transparent line and a transparent scale, one of which is carried by the head and the other of which is carried by the feeler, the line and scale being in alignment with a hole passing through the head transversely to the direction of movement of the feeler. The feeler 5 is slidable in the head 1 which is secured to the handle 3 and a scale marked on a transparent plate 7 is mounted in a hole in the feeler adjacent to a vernier scale or index line on a transparent disc 10 adjustably secured in the head. A sprung rod 15 has a part-conical portion which co-operates with a corresponding slot in the feeler 5 to hold the latter, against the action of a spring 18, in the innermost position it adopts when a bore is gauged. The gauge may then be withdrawn from the work and the scale read by means of a magnifying lens 13 secured in the head, the opposite end of a tube 21 slidable in the handle 3 being closed by a transparent disc 22. The feeler may be released by depressing the tube 21 so that a bevelled rod 19 operated thereby moves the rod 15 against its spring. The Specification as open to inspection under Sect. 91 comprises also an embodiment in which the scales and lens are arranged in a transverse hole in the head which is perpendicular both to the handle and to the feeler. The locking device is released in this case by a press-stud which is arranged to withdraw a sprung member from engagement with the locking pin. This subject-matter does not appear in the Specification as accepted.