Patent GB-446266-A (GB)
Title: Improvements in and relating to free wheel brake hubs
IPC: B62L5/04
Filed: 1934-09-25
Abstract: 446,266. Coaster hubs. FICHTEL & SACHS AKT.-GES., Schweinfurt, Germany. Sept. 25,1934, No. 27559. Addition to 420,550. [A Specification was laid open to inspection under Sect. 91 of the Acts, March 26, 1935.] [Class 136 (ii)] A free-wheel, back-pedalling brake hub with means for locking the braking-means in the braking position to relieve the effort of back pedalling, is characterized by the provision of spring means which act upon the locking means in such manner that the braking action is variable, by forward or backward pedalling, without affecting the back-pedalling relief. As shown, the locking-means comprise teeth n<1> rigid with the driver b and teeth m carried by a cross-bar l slidable in a slot in the axle h, the teeth being kept apart, when pedalling forward, by a spring o. The chain sprocket is secured to the driver b by a lock-nut c and a cap d, with felt packing d<1>, is screwed on the driver against the lock nut c. The cap d has internal face cams d<3>, Fig. 5, with sloping ends d<21>, d<5>, the ends d<5> overhanging to engage the sloping ends g<5> offace cams g<2> on a ring g, Fig. 4, which is accommodated within the cap d. The ring g has deep internal cam-like recesses g<7> which accommodate rollers f<1> carried on a ring f, Fig. 3, in such manner that when back pedalling starts, the rollers are forced into recesses e<1>, Fig. 2, on the cone e which is prevented from rotating by a pin i passing through slots h<1> in the cone and in the axle h. The ring g is thus temporarily locked to the cone e. Springs f<2> on the ring f bear on the fluted part of the cone e and impose a slight frictional resistance to the rotation of the ring f. When the ring g is locked by the rollers f<1>, further back-pedalling rotates the cap d so that the face cams g<2>, d<3> ride on one another and the ring g is forced axially towards the brake, so that teeth g<1> on the edge of the ring g engage suitably shaped parts of the pin i which is forced towards the brake and, by means of an interposed strong spring k, moves the bar l against the action of the weak spring o. This causes the teeth m, n<1> to mesh and lock the driver b. The locking is, however, resilient since the yielding of the spring k permits the driver b to be rotated forward or backward to vary the braking effort, the teeth m, n<1> then meshing in a new locking position. When the forward propulsive effort is resumed, the components of the lock return to their initial positions. The braking-means may be rendered inoperative by providing a radial screwed hole in the cap d in which is screwed a pin with a reduced end, the pin projecting through a hole in the ring g to lock the ring f thereto. When the screwed pin is removed to render the braking-means operative, the screwed hole is closed by a grub screw. Alternatively, a slidable bar is arranged in the cap d tangentially to the ring f. The bar has a cam face which, when the bar is slidably displaced, presses a spring member secured to the cap d into recesses in the rings g, f. The members d, g, f being thus locked together, the braking-means are rendered inoperative.