GB711213A - Improved change speed gear for motor vehicles - Google Patents

Abstract

711,213. Variable-speed gearing; clutches. KREIS, F., and S.I.B.A. SOC. ITALIANA BREVETTI AUTOMOBILISTICI AR.L. Sept. 14, 1950 [Dec. 6, 1949], No. 22617/50. Class 80 (2) A partially automatic variable speed gear for a vehicle providing five forward speeds plus reverse, comprises a three-position manual control of three ball clutches and three automaticallyengaging centrifugal clutches A, B, C, the clutches B, C having additional centrifugal weights arranged so that the driver may hasten the automatic engagement by temporarily releasing the throttle. In first gear, the engine is connected through clutch A to a gear 1 which drives a countershaft 4 through gear 2 and freewheel 3. A gear 5 is connected to the countershaft 4 by a ball-clutch 6 and drives the output shaft 15 through gear 11 and freewheel 12. As the speed increases the weights B which are rotated from the countershaft through gears 13, 14, move outwards to clutch gear 14 to the engine and engage second gear, the engine then driving the shaft 15 through gears 14, 13, 5, 11 and freewheel 12, the freewheel 3 overrunning. As speed further increases, the weights C carried by shaft 15 move outwards to clutch the shaft directly to the engine and thus engage top gear, both freewheels 3 and 12 overrunning. A greater step-down ratio in first and second gears may be obtained by transmitting the drive from countershaft 4 to the shaft 15 through gears on a parallel secondary shaft 17, Fig. 3. This transmission is obtained by sliding ball-clutch sleeve 7, Fig. 1, to the right to allow the balls 6 to move out of grooves in the shaft 4 and thus disengage the gear 5 from this shaft a second ballclutch sleeve 9, Fig. 3, connected to the sleeve 7. being simultaneously moved to cause balls 16 to leave a recess in the sleeve and enter grooves in the shaft 17, thereby coupling gear 18 to a gear 21 on the shaft 17. Countershaft 4 then drives shaft 15 through gears 20, 21; 18, 19; and 19, 11. To engage reverse gear, the sleeves 7 and 9 are moved further to the right, whereby ball clutches 6, 16 are disengaged and a ball clutch 22 is engaged to couple gear 21 to gear 23, the latter gear directly driving a gear 24 on the shaft 15. For engine braking, the freewheel 12 is locked by sliding gear 24 to interengage corresponding claws on the gears 24, 11. The weights B, C each have pairs of balls 52 cooperating with spring-loaded wedges as described in Specification 702,796, and their outward movement is resisted not only by tie springs but also by axially-movable members controlled by additional centrifugal weights carried by the driving half 54 of the clutch so that the resistance to clutch engagement is influenced by engine speed, i.e. by throttle control, as described in Specification 711,212. Cushioning springs 56 are provided between the clutch hubs and the weight carriers.