GB165510A - Improvements in measuring machines and measuring instruments - Google Patents

Abstract

165,510. Gowlland, C. S., and Pailthorpe, A. L. March 22, 1920. Indicating; optical devices for.-Relates to instruments and machines for measuring linear dimensions of the kind having fixed and movable anvils the movement of the latter being indicated by a beam of light reflected from a mirror moving over a scale, and consists in the provision between the movable anvil and the mirror of a separate motion-transmitting or movement magnifying mechanism. In the form shown in Fig. 2 the amplifying-means comprises a triangular lever 2 pivoted, at one corner 3. A knife-edge on the movable anvil 7 engages one edge of the lever 2, the opposite angle of which abuts against a lip 11 on a disc 10 pivoted at 9 and carrying the mirror 12. The mirror mav be mounted on the arbor of a ciagauge in addition to the ordinary needle, and in the form shown in Fig. 8, the rack 34 is formed on the lever 2 and is marked with figures one of which is visible through a hole 36 in the scale plate and indicates the number of complete turns made by the needle. The device may be fitted with several mirrors some of which move through greater angles than others for a given anvil movement. The mirrors may be arranged as the sides of a multi-sided prism. The reflected beam may pass through coloured screens arranged between the mirror and the scale for limit gauging.