Patent GB-435278-A (GB)
Title: Power transmission systems, particularly for motor-vehicles
IPC: F16D47/04
Filed: 1934-04-06
Abstract: 435,278. Clutches; couplings; variablespeed gearing. STANDARD MOTOR CO., Ltd., GRINHAM, E. G., and DAWTRY, L. H., Canley, Coventry. April 6, 1934, No. 10424. [Class 80 (ii)] A power transmission system, particularly applicable to motor vehicles, comprises a roller-type freewheel having its cam or driving part loosely splined on the driving shaft to give limited angular movement and provided with masking teeth, and a sliding clutch member for positively locking the driving shaft to the driven member of the freewheel, said clutch member having masking teeth to coact with those of the cam to prevent positive locking until synchronism is reached in the parts to be coupled. The freewheel 12, Fig. 1, is arranged at the rear end of a gear-box 13. The reverse drive is obtained by sliding the gears 15, 16 into mesh with gear 17 on the layshaft 18, and gear 19 on the driven part 14 of the freewheel respectively. The cam portion 20 of the freewheel is so splined on the driving shaft 21 as to have an angular movement relative thereto of about 7‹ and it engages the driven part 22 through groups of rollers 23. The part 22 has teeth 24 adapted to be engaged by teeth 25 on a slidable clutch member 26 when permitted to do so by masking teeth 35, 36 formed respectively on the cam member 20 and clutch member 26. This clutch member is actuated against a spring 34, through a lever 30, Figs. 1, 2, integral with a sleeve 29 mounted, with lost motion at 32, on a shaft 31 having an arm 33 connected to the main clutch at the front end of the gear-box. The sleeve 29 also carries an arm 28 adapted to be engaged by a latch 27 actuated from the instrument board to hold the locking means out of action. The angular movement of the cam member 20, relative to the shaft, to cause the masking teeth to abut and prevent engagement may be produced by a spring, or the frictional drag of the member 22 may be sufficient. Gear changing, assuming the freewheel is locked solid, is effected as follows. On releasing the main clutch, the clutch 26 is released and, at the same time, a brake 38 is applied to a drum 39 on shaft 21 by an arm 37 on shaft 31. The driver then pauses a moment for the gear-box parts to come to rest, the change-speed lever is moved to neutral and then the fresh speed can be silently engaged, the lay and driving shafts usually revolving slowly under clutch drag. On releasing the main clutch pedal, the clutch 26 will engage when the freewheel starts to take up the drive and the masking teeth move relatively into meshing position. To prevent binding of the clutch member 26 on shaft 21 due to torque reaction, it is mounted for slight angular movement on the shaft as shown in Fig. 4. The shaft splines have clearance in the clutch sleeve and two opposite splines are engaged in notches 40 in plugs 41 loaded by springs 42 so as to relieve any load on the faces 44. The drive is taken on the other faces 45. When the accelerator is released, the parts are enabled to " give " slightly and ease the pressure on the teeth 24, 25 and facilitate the disengagement of the clutch 26.