GB553213A - Improvements relating to vernier gauges - Google Patents

Abstract

553,213. Vernier gauges. GRAY, C.. A. and KOOPMAN, J. M., Jan., 8, 1942, No. 329. [Class 106 (ii)] [Also in Group XXIII] The gauge, for example, a height gauge " with a scribing point on, the movable, jaw, is provided; in: addition to the usual scale and vernier; with a supplementary vernier and associated scale for use in setting the movable jaw to a position along the scale displaced from the initial position. The scale. bar 1 has a fixed jaw 3 and movable jaw 2, the latter carrying a scriber 4. The jaw 2 also incorporates a head' 5 sliding on the bar 1. The latter comprises two opposed cheek members 6, 7 embracing the bar. 1 and also two opposed supplementary cheek members 10; 11 having flanges 12, 13. The head 5 carries a vernier 15 reading through an opening 16 a scale 14 on the bar 1. Also carried in the head 5 and extending along the opposite side of the opening 16 is a second vernier 17 co-operating with a scale 18 on the supplementary cheek member 11. The members 10, 11 are slidably mounted on the adjacent edge of the bar 1 within the limits set by the space 19 between the top and bottom of slide 5, projecting part' 22, 23 being guided in grooves running the full length of the bar 1. A clamping shoe 26 engages the edge of the bar, and two of the clamping shoes 27, 28 are provided as shown. A double-acting set-screw 30 extends through a slot in the part 9 and is provided with left- and right-handed screws 31, 32 to engage the shoes 27, 28. Leaf springs 34, 35, 36, 37 are arranged as shown. By turning the screw 30 clockwise, the shoe 26 grips the bar 1 and the shoe 28 the part 9. By turning the screw counterclockwise, the shoe 26 is released and the shoe 27 moved to grip the flanges 12, 13 and thus the scale 18. An axially fixed screw turned by a knurled head 37 passes through a nut 38 joining the tops of flanges 12, 13. In use, the screw 30 is slacked so that no brake shoes bind and the head 5 adjusted by hand until the scriber is approximately at the hole centre marking position. Then the parts 10, 11 are locked by turning the screw 30. Now the screw 37 is turned one way or the other to adjust the head 5 along the bar until the exact position of the hole centre is reached. The screw 30 is turned to unlock the parts 10, 11 and to lock the head to the bar. The hole-centre marking is then scribed on the jib. The base markings are then to be scribed. For this, the screw 37 is turned to bring " zero " on a scale 18 opposite the " zero " of the vernier 17. The screw 30 is turned to lock the parts 10, 11 to the scale bar and unlock the head, whereupon the head is adjusted by turning screw 37 to the required distance using scale 18 and vernier 17. The head is now again locked and the line scribed. In a modification, the scale 18 slides in a groove in the bar 1 and is attached to a part sliding on the bar and connected to the head 5 by a fine screw adjustment the vernier being on the head.