GB239937A - Improved variable-speed gear - Google Patents

Abstract

239,937. Worthington, R. C., and Milner, H. June 19, 1924. Variable-speed and reversing gearing comprises a three-speed epicyclic arrangement operated automatically by a sliding face cam 5, Fig. 1. The cam 5, which slides on a driving- shaft 2 against a control spring 36, coacts with a like member 18 secured to an aligned middle shaft 17. The shaft 17 is integral with a sun gear 17<a> which meshes with stepped planet gears 23 carried by a driven plate 21. The gears 23 mesh with a one-way revoluble internally-toothed gear 24 and with idlers 23b, Fig. 2, which mesh with a loose sun gear 15<b> integral with a clutch disc 15. The cam 5 is integral with a face clutch 19 which is normally held by the spring 36 in engagement with the disc 15, whereby the parts are locked for solid driving. Increase of load causes the cam 5 to move to the left of Fig. 1, disengaging the clutch 19, and applying a brake 14 to the disc 15. Epicyclic action causes the disc 21 to be driven at middle speed. Further increase of load releases the brake 14, upon which the ring 24 tends to run backwards, but is prevented by a detent such as a wedging ball 25, Fig. 2. This brings the lowest speed into action. A spring catch 37 helps to make the stepped changes definite. Reversed driving may be effected by a train 21<b>, 34, 35, 35<a>, 29. The toothed wheel 29 slides on an ultimatelydriven shaft 30 and carries clutch dogs 29b adapted to engage for forward driving with holes in the gear 21<b>, which is fast with the disc 21. Movement of the wheel 29 to the right brings to neutral. The meshing set 34, 35, 35<a >is carried on a pivoted arm 32 which is depressed to connect the reversed drive.