Patent GB-730334-A (GB)
Title: Improvements in or relating to means for axially locating a rotatable sleeve on a spigot
Inventor: LOXHAM JOHN
IPC: G01B5/00
Filed: 1951-12-22
Abstract: 730,334. Retaining members on shafts. SIGMA INSTRUMENT CO., Ltd. March 23, 1953 [Dec. 22, 1951], No. 7977/53. Divided out of 730,285, [Group XXXVIII]. Class 80 (2). [Also in Group XIX] Means for obtaining axial location of a rotatable sleeve on a spigot comprises a flangelike termination at one end of the spigot having a reference face for engaging one end face of the sleeve and means for resiliently pressing together the end face and reference face, one of these faces having a plurality of projecting spaced pads with reference surfaces contacting the other face, the contacting surfaces of the pads and face lying in planes truly perpendicular to the axis of rotation of the turret sleeve. The invention is shown, Fig. 1, embodied in the turret comparator described in Specification 730,285, [Group XXXVIII], wherein the turret comprises a sleeve 86 rotatably mounted on a spigot 87 extending forwardly from an upright 5, which is formed with a hole 95 truly perpendicular thereto for receiving a heavy pin 97 which also lies in a truly axial hole 96 in the spigot 87, which, being thus correctly aligned, is attached to the upright 5 by a screws 98. The outer end of the spigot 87 receives a cap 104, Fig. 3, corresponding faces being flat to a high degree of accuracy, the end face of the spigot being truly perpendicular to its axis. Outside a groove 105, the cap 104 is ground away to leave three equi-angularly spaced pads 107 preferably grooved for lubrication, the pads forming truly' co-planar reference surfaces. A register pin 113 lies in holes 110, 111 in'the cap and spigot respectively, all accurately formed to ensure exact alignment and the cap is secured by three screws 112 entering holes 108, 109. A disc 114 is secured over the cap 104 by three screws 115 entering the remaining holes 108, 109 and the disc 114 is formed with a hollow axial extension 116 upon which is freely mounted a control head 117 retained by a screw 117A and connected to the'turret sleeve 86 by a pin 117B extending into a hole in a gauging fixture clamping block 117C to provide means for turning the turret sleeve 86 on the spigot 87 to. bring any desired gauging fixture into gauging position. The upright 5 is drilled in several places to receive hollow plungers 118. The drilled holes are shouldered at 119 and screw-threaded to receive screw caps 120 against which bear springs 121 contained in the hollows of the plungers which are thus urged forward through holes in a dished circular plate 122 which receives an annular member 123 stepped to receive a ring 124 secured thereto to form a raceway for balls 125 engaging a face of the sleeve 86. Both this face and the opposite end face of the sleeve 86, which engages the three pads 107, are made accurately flat and truly perpendicular to the axis of the sleeve. Thus axial location of the sleeve 86 is obtained by the plungers 118 pressing it into contact with the pads 107 of the cap 104 whose peripheral portion forms in effect a flange of the spigot 87. The pads 107 could be formed on the end face of the turret sleeve, the peripheral portion of the cap then being made truly flat. Diametral location of the sleeve on the spigot may be obtained by means described in Specification 730,335.