GB395350A - Improvements in change speed gearing - Google Patents

Abstract

395,350. Change-speed gearing. CHAMBERS, J. H., 4, Harberton Park, Belfast. Oct. 10, 1931, No. 28191. [Class 80 (ii).] Variable-speed gearing comprises an epicyclic train h, g, f and means associated with a layshaft l for driving and stationing alternatively the sun gear h which is loose on a driven shaft d. The lay shaft l is constantly driven by a pair b, k from a driving-shaft a. Splined on a boss c of the gear b is a dog clutch member c<2>. Planets g are supported on pins g<2> in a flange e rigid with the shaft d. Rigid with the sun h is a gear i constantly meshed by a gear n which is loose on the shaft l and has dog ends for engaging alternatively a clutch member m<2> fast on that shaft and a dog o rigid with the gear casing. Fourth speed is a direct drive obtained by engaging the dog clutch c<2> with projecting ends of the pins g<2> which are squared for the purpose. For third speed, the sun gear h is held fast by engaging the gear n with the dog o, and the internal ring f of the planetary train is driven from the shaft a by engaging the clutch c<2> with dogs f<1> on the ring f. For second speed, the clutch c<2> is moved to neutral and the ring f is held fast by dogs q provided for the purpose. The dogs q are pivoted on a support wand are adapted to engage the dogs f of the ring f. At the same time, the sun gear h is driven through the layshaft by engaging the gear n with the dog clutch m<2>. For first speed, the sun gear h is driven as above, but the ring f instead of being held fast is driven reversely by sliding in an idler p to connect external teeth f<2> on the ring with a pinion m on the layshaft l. Reversed drive is obtained from the slow backward drive of the ring f by holding, the sun h fast by sliding the gear n to engage the dog o. If it is desired to take the drive from both ends of the gear box, the drive may be applied to an extension a2 of the shaft l and the driven shaft d may be extended to project at d<3> from the left side of the gear box as well as from the right side. A selector device is described for operating the clutches two at a time as required. In a modification, the first forward speed is omitted, there being no external teeth f<2> and no pinion m. An idler is interposed between the gears corresponding to n and i so that the loose sun h is driven at a slow reverse speed from the layshaft which is used for reversed drive when the ring f is held by the dogs q, and for lowest forward speed when the ring f is driven by the clutch c<2>.