GB911950A - Improvements in or relating to measuring devices and mountings therefor - Google Patents

Abstract

911,950. Machine-tool details. HODGE CORPORATION, M. E. Dec. 15, 1959 [Dec. 16, 1958], No. 42625/59. Class 83 (3). A friction wheel type measuring instrument comprises a shaft 28 carrying a contact wheel 30 projecting from one face of a housing 10 and gears 36, 38, 40, 42 interconnecting the shaft with at least one other parallel shaft 32, 34, the shafts and the housing carrying co-operating scales 50, 52, 68 and indicating members 60, 66, 70. The gears 36, 40 are made in two halves connected by spring means to obviate lost motion. The circumference of the contact wheel is equal to six units and the gearing ratio is such that the contact wheel rotates through one unit while the second shaft 32 makes one revolution and the third shaft 34 makes ten revolutions. The scale 50 on the shaft 28 cooperates with the engraved mark 60. The pointer 66 on the shaft 32 co-operates with the fixed circular scale 52. The pointer 70 on the shaft 42 co-operates with an annular scale 68 on a rotatably mounted bezel 72. A spring- pressed wiper 86 surrounds the edge of the contact wheel 30. The contact wheel is of a metal having a very low co-efficient of expansion and contains a rubber friction ring 96 within a grooved recess. The instrument is mounted in a channel on a slide 112 which can be retracted on a base 104 against a spring by a handle 140 rotating a cam-rod 138. The channel has a sidewall 152 which can be moved laterally to clamp the instrument. The base 104 is attached to a bracket 160 on a lathe and is adjusted angularly by screws 176, 178 to position the contact wheel 30 against a surface 164. The apparatus may also be used in milling, drilling or shaping machines.