GB567340A - Improvements relating to epi-cyclic change-speed gearing - Google Patents

Abstract

567,340. Variablespeed gearing. STURMEY-ARCHER GEARS, Ltd., and BROWN, W. Feb. 25, 1943, No. 3111. [Class 80 (ii)] A variable-speed gear comprises two side-byside epicyclic gear trains with the planet carrier, of one positively coupled to the annulus of the other, said annulus constituting an output member, means for selectively coupling an input member to either the planet carrier or annulus of the same train, and means for selectively connecting the sun wheel of the same train to the planet carrier of the said other train or to a non-rotating member. As applied to a cycle wheel hub 6 one train comprises an annulus 11, planets 12 in a cage 18, and sun 13 loose on the stationary axle 1. The second train has an annulus 14 fixed to the hub 6, planets 15 in a, cage 29, and a sun 16 fixed to the axle 1. A dog 25 on a slidable sleeve 24 continuously engages dogs 9b on an input member 9 to which the driving sprocket 3a is fixed. Dog 25 may engage either dogs 17 on the cage 18 or dogs 26 on annulus 11. A slidable sleeve 27 has dogs 28 continuously engaging dogs 13a on sun 13 and also engageable with dogs on the carrier 29. Sleeve 27 also has dogs 30 engageable with dogs 31 on the shaft 1. The sleeves 24, 27 are moved by pins 22, 23 upon sliding movement of a control rod 21, an abutment 34 being provided on the rod 21 to engage pin 23. As shown a direct drive takes place from the member 9 to the hub 6 through the planet cage 18. If the dog 25 is engaged with dog 26 the hub 6 is driven through differential operation of both gear trains. If now the sleeve 27 is moved to engage dogs 30, 31 the hub is driven through the train 11, 12, 13 alone, the secondary train being idle. The invention may be embodied in a gear according to Specifications 519,945 or 527,837, by omitting the pawl and ratchet drive to the annulus and converting the other to a positive drive. Specifications 473,205, 483,992, and 541,332 also are referred to.