GB300667A - Improvements in changegear mechanism more especially applicable to automobile vehicles - Google Patents

Abstract

300,667. Lanchester, F. W., and Lanchester's Laboratories, Ltd. July 9, 1927. Variable-speed gearing comprises two or more units of epicyclic gear trains controlled solely by axial movements of frictional elements in combination with means for maintaining a frictional element in freed position so as to yield free engine ' when desired. In the arrangement shown in Fig. 1, there are two two-speed units A, B, and a reversing-gear C. In unit A, the internal ring d is secured to the driving-shaft d', the planet carrier c is secured to the driven shaft f, and the sun gear g is adapted to be clutched solid, or held fast, or, by additional means, freed. The sun gear g is long and is adapted to slide with its sleeve g<1> and a double cone clutch n<1>, n<2>. A spring h normally holds cone n' engaged with a cone k on the ring d for solid driving. To bring in the low speed, the controlling element m, which is a non-rotating cone, is slid to the left so as first to engage cone n<2> and then to slide the double cone to the left disengaging cone n<1> and holding the engaged parts against rotation. This control movement is effected from a pedal through a rock-shaft S, Fig. 2, and arms s<1>. Separate means to disconnect the drive comprises a second rock-shaft t, which has arms t<1> acting through a thrust bearing 45 on the end of sleeve g<1>. Selectively operating pneumatic plungers are described by which either of the shafts s, t can be operated by depressing the pedal. The shaft f is the driving-shaft of the second unit B, of which the sun gear o drives and the planet carrier 48 is driven. The double clutch 20 is on the ring p and speed is changed by sliding a non-rotary friction member r. r. This effects that ring p is clutched solid or held fast alternatively. No free position is required here. Four speeds have thus been given to shaft 32. The reversing unit C comprises a planet carrier 34, with rings of clutch teeth 36, 37. When this is slid to the right, the teeth 37 engage over the driving sun pinion 33 locking the train 33, 46, 47 to turn solid. When the carrier 34 is slid to the left, the teeth 36 engage fixed teeth 35 so that the pinions 46 turn on fixed pivots and drive the ultimately-driven ring 47 backwards.