Patent GB-562686-A (GB)
Title: Improvements in or relating to spring suspension devices for bicycles and like vehicles
IPC: B62K25/24
Filed: 1942-11-27
Abstract: 562,686. Spring frames for cycles &c. BALLAMY, L. M., SHEEPSHANKS, R. H., and G. B. (NOTTINGHAM), Ltd. Nov. 27, 1942, No. 16914. [Class 136 (iii)] A resilient suspension system for a bicycle or like vehicle comprises a pair of arms pivotally mounted side by side to rise and fall about a common pivotal axis, a spindle connecting the free ends of the arms on which a road wheel is mounted and a pair of torsion bars disposed one on each side of the wheel, one end of each torsion bar being connected by toothed gearing with the pivotally mounted part of the corresponding arm and a part of the torsion bar remote from the gearing being anchored, so that upward movement of the wheel and arms causes the torsion bars to be twisted. A frontwheel motor cycle suspension is shown in Figs. 1, 2 and 3, the fork structure comprising parallel tubes 10, 11 connected by a transverse bar 13 with a stem 12 which is angularly movable for steering purposes in the usual head tube 14. The front wheel 15 has a tubular hub 16, Fig. 2, freely rotatable on an axle tube 17 on ball-bearings 18, 19 protected from dirt by rotating seals 22, 23, a rod 26 clamping the tube 17 between a pair of arms 24, 25. A rigid spindle 28 on each arm extends rotatably through a tubular bush 29 and is provided with a rigidly-secured bevel gear-wheel 30 meshing with teeth 50 on sleeves 46, 47 splined to the lower ends of torsion bars 42, 43 within the tubes 10, 11. Splined heads 51, 52, Fig. 3, at the upper ends of the torsion bars engage splined bores of U-section adjusting collars 53, 54 rotatably'mounted in the upper ends of the tubes 10, 11, axial movement of each collar being prevented by a gland nut 55, while the collars are spaced by a plate 57 clamped centrally to the stem 12. Arms 64, 65 integral with and projecting from the collars are connected by a device for adjusting the stress in the bars 42, 43, the device comprising a head 67 having oppositely-threaded stems 68, 69 engaging sockets 70, 71 pivotally connected with the arms 64, 65 so that rotation of the head moves the arms towards or awav from each other. The toothed gears are held in firm engagement with each other by resilient sleeves 33, 34, Fig. 2, which are compressed considerably on assembly and act as cushions to permit a limited radial movement of each spindle 28. The wheel hub 16 is formed with a brake drum 74 having a non-rotatable backplate 75 for carrying the usual brake shoes (not shown) and rotation of the backplate due to drag of the brake shoes is prevented by a link 76 pivotally connected with the plate and with the housing 35. In the rear-wheel suspension shown in Figs. 4 and 5, the torsion bars 42, 43 are enclosed in the tubular seat stays 79, 80 and a sleeve 46 at the lower end of each bar is formed with teeth meshing with a bevel wheel 30 which is mounted on a spindle 28 and is angularly movable with an arm 24a on which the wheel is mounted. The upper ends of the bars are secured to collars 53a, 54a rotatable on the tubes 79, 80 and having arms 64a, 65a connected by a two-position adjusting tie device 81. This device comprises a forked link 82 connected to an eye link 83 by an eccentric 84 manually rotatable in the eye 85 of the link 83, the eccentric being rotatable from its normal position into a, position just past the deadcentre position to shorten the device and increase the stress in the torsion bars. Driving means as described in Specification 562,169 may be provided comprising a driving wheel driven from a longitudinal shaft by skew, bevel gearing, &c. and mounted coaxially with the spindle 28 to mesh with a driven wheel carried by the road wheel.