GB785720A - Improvements in or relating to measuring heads for gauges - Google Patents

Abstract

785,720. Linear-dimension gauges. SIGMA INSTRUMENT CO., Ltd. Jan. 16, 1956 [Feb. 18, 1955], No. 4934/55. Class 106 (2). A measuring head for gauges comprises a base member 1, Fig. 1, a floating member 5 supported therefrom and carrying an anvil 2, adjustably fixed contacts 25, 29, Fig. 3, and movable contact means 21 arranged to move in accordance with the displacement of the floating member 5 to encounter the contact 29 if the gauged dimension is of, or greater than, a first predetermined amount and to contact the contact 25 if the gauged dimension is of, or less than a second predetermined amount as in Specification 594,450, a conduit 46 leading to an orifice 48, and a needle 38 co-operating with the orifice and moved in accordance with the displacement of the floating member as in Specification 724,228 to indicate the amount by which the gauged dimensions are greater or less than the above-mentioned predetermined amounts. The floating member 5 is secured to the base by means of springs 6, 7 arranged as in Specification 780,871, [Group XXIV]. The movable contacts are secured to a blade 21 fixed to a channel member 20 attached at its lower end to a lever 16 pivoted on a shaft 17 and having a sapphire 18 engaging a knife edge block 19 engaged by the floating member 5. Screws 5B are provided by which the point of contact of the knife edge on the sapphire 18 may be varied to adjust the angular position of the channel member 20. The movements of the floating member 5 are communicated to the needle 38 by means of a block 39 having a knife-edge engaging a sapphire 37 on a lever 34 pivoted at 35 whose other arm has a sapphire 36 forming a bearing for the lower end of the needle 38. The block 39 may be vertically adjusted by screws 53 and shifted laterally by an adjusting screw 52. Specification 724,205 also is referred to.