Patent GB-221996-A (GB)
Title: Improvements in or relating to change speed devices
IPC: F16H3/66
Filed: 1923-11-12
Abstract: 221,996. Joseph, F. A. Nov. 12, 1923. Variable-speed epicyclic gearing of the kind in which more than two step-by-step gear ratios are provided by the use of a single brake comprises selector means for sliding axial clutches into and out of engagement with axial gears so as to effect gear ratios in any desired order. In the arrangement shown in Fig. 1, stepped planet gears f, f<1>, - - f<4> secured to spindles e are supported in a cage b loose upon aligned driving and driven shafts a, d. When a clutch v is engaged, the gearing rotates solid. When a loose gear g meahing with the planets f is held by a brake t, sun gears h<1> - - h<4> are driven at different speeds forwardly, and one may be driven reversely. These sun gears may be connected alternatively to the driven shaft d at will by two sliding dog clutches n<1>, n<2> selectively operated from a hand lever o working in a gate. The clutch n<1> is in the form of a head on the solid shaft d which slides in a transmitting coupling 37, and the clutch n<2> is on a sleeve splined to the shaft d. The selector mechanism is shown in Fig. 11. The lever o is secured to a rock bar 62 having operating arms 63 and slides axially to make selection along with a non-revoluble sleeve 62a having locking arms 63a. In the configuration shown, one striker 66 is about to be operated by the upper arm 63 while the other striker 66<a> is locked bv the lower arm 63a. On sliding the lever o to the right, the striker 66a is engaged by the lower arm 63 and the striker 66 by the upper arm 63a. The brake preferably comprises a pair of pivoted blocks t, Fig. 8, expanded by a pair of cams 85 shown also in Fig. 5. In this Figure, 71 is a through shaft operating the direct-drive clutch v of Fig. 1. A pedal-lever 69 thus controls both the brake t and the clutch v. As used on a vehicle, to apply the brake t, say after one of the axial clutches has been brought in by the hand lever o, the pedal 69 is depressed from neutral position 73 to position 72. To apply the direct-drive clutch v, the pedal is allowed to rise to position 74. The connection with the brake-operating cams 85 is through a spring 81 which expands until a stirrup 86 strikes a collar 92a cutting out the spring and transmitting a positive pull. The lever 69 is locked by a spring bolt 91 operated by an auxiliary lever 86 pivoted upon the pedal 70. A heel 89 upon the lever 86 projects through the pedal 70 so that the operator can unlock the pedal lever 69 and operate it with the same foot. In place of the gear pair f, g of Fig. 1 for connecting the planet spindles to the brake, a set of cranks 53, Fig. 3, may be used making connection with an eccentric ring 56 mounted in a bearing 57 in a brake drum 58. In a modification, there are two separate and different sets of group planet gears mounted in different planes in the same loose cage, and the changes are effected by axially sliding clutch members under arbitrary control. In a further modification, the planet cage is secured to a driving flywheel, and the clutch and brake are arranged at the other end of the gearing. In a Provisional Specification, a form of brake is described comprising semicircular spring-pulled shoes or blocks adapted to be thrust outwards into engagement by a pair of sliding wedges between their ends.