GB856691A - Improvements in or relating to the building of spoked wheels - Google Patents

Abstract

856,691. Screwing-up wheel-spoke nipples. T.I. (GROUP SERVICES) Ltd. March 8, 1957 [Dec. 9,1955], No. 35366/55. Class 83 (3). [Also in Group XXXV] Apparatus for trueing previously-laced spoked wheels by selectively tightening the spokes, comprises a collet gripping the lower part of the hub of the wheel w, Fig. 1, and a motor 25 rotating the spindle of the wheel and a radial arm 26 provided with magnetic pick-ups 27, 28 sensitive respectively to axial and radial errors in the rim portion it is traversing, and controlling the screwing-up of the spoke nipples by units 29, one of which is provided for each spoke, and each of which includes a torque-responsive switch, connected so that when the torque applied to a predetermined number of the spokenipples exceeds a predetermined value, the trueing operation is terminated and ejectionprocedure initiated. The spoke-nipples are engaged and disengaged by rocking the brackets 140 carrying the units 29, by a timing cam-shaft controlling the sequence of events before and after trueing takes place. The wheel-hub is gripped by a split collet 20, Fig. 2, in a holder 51 which is raised and lowered at the beginning and end, respectively, of the operation, by a cam 54 with follower 53 on a coupling-tube 52. The collet is tightened by a tapered sleeve 56 urged upwardly to the position shown by spring 60 and rod 62, and loosened when a shuttle 69 linked to 62 is moved to the left; the shuttle is operated by tappets 70, 71, on plungers 73 controlled by cam 78 via follower 77. A further cam 87 and follower 86 act via links 83, 81, Fig. 1, to raise and lower the whole upper-head assembly. This latter includes a coupling from the motor 25, Fig. 3, to the spindle-collet 23 and radial arm 26, comprising slidable square coupling 90 and two universal joints 91, to enable the collet to move without restraint during rotation. The collet 23 is closed in a similar manner to collet 20 by downward movement of sleeve 93; this is effected by solenoids 94, 95, which through a toggle 98, 92, move a collar 100 and spigotmember 102 downwards, and the tapering surface 108, Fig. 3A, of 102 operates bell-cranks 109 to push 93 down. The nipple-rotating units 29 are initially moved towards the centre of the wheel w by downward movement of a plate 146, Fig. 2, which rocks brackets 140 carrying the units, the wheel is then inserted, and the timing camshaft operates collet 20, as described above, to grip the wheel and lower it so that each spoke passes through slots 39, 37, Fig. 5, of a unit 29; a further cam (not shown), then raises 146 so that units 29 move outwardly and sockets 38 engage the square-section nipples on the spokes. Collet 23 is then operated to grip the wheel spindle, and the.arm 26 is rotated to measure the mean inductances detected at 27, 28, and set those up as reference inductances for the wheeltrueing operation which follows. The electric circuits then operate (see Group XXXV), to tighten the spokes, by groups of four units 29 in succession, as the arm 26 rotates. Driving-shaft 121, Fig. 6, of each unit is connected by a torsion-bar 122 to a tubular shaft 123 carrying a pinion 124 which drives the slotted pinion 36 via pinion 125. When the spoke reaches a predetermined tension, the torque, and hence the twist, in 122 causes electric contact between a pin 129 on 123 and a segment 126 into a hole in which it projects; this is used to switch-off the spoke-tightening motor, and when a predetermined number of spokes have been so tightened the operation is terminated. To eject the wheel, the pinions 38 must be rotated so that their slots 37 are aligned with the slots 39, in which position the units 29 may be disengaged from the spokes: a wiper contact 41 attached to each pinion 125 contacts one of the two fixed segments 42, 43, if the slots are not aligned, and this switches the nipple-motor to rotate 41 towards a gap 44 between the segments, whereupon the motor is switched-off with slots aligned.