GB463513A - Automatic control mechanism for change-speed gearing for motor and the like vehicles - Google Patents

Abstract

463,513. Variable - speed gearing. MAILLEUX, A. L. March 23, 1936, Nos. 8582 and 8583. Convention dates, March 21, 1935 and Sept. 13, 1935. [Class 80 (ii)] A variable-speed gear automatically controlled in accordance with speed and load comprises a splined driving-shaft 1 carrying a number of worm-wheels 28, the threads of which co-operate with threads inside sleeve portions of clutch members 4. Pinions 5 of decreasing diameters are rotatably mounted upon each of the said sleeves and adapted to engage with the clutch members 4 under the pressure of springs 7 arranged between each clutch member 4 and the next pinion so that an equal engaging pressure is applied to all the clutches. The pinions are in constant mesh with pinions 15 mounted on a driven shaft 2, these pinions driving the shaft 2 through one-way devices 16. Carried'on the driving shaft 1 are centrifugal weights 24 which act upon a sleeve g to regulate the compression of the springs 7 according to the speed of the driving shaft. A further set of centrifugal weights 27 driven by gearing 17, 18 off the driven shaft 2 effect a further regulation of the springs 7 according to the speed of the shaft 2. The tendency of the load or resisting torque is to disengage the clutches 4, 5, owing to the action of the worm-wheels 28 on the clutch members 4, against the engaging pressure of the springs 7. Thus, if the torque is too great for the largest pinion 5, which gives the high-speed drive, the associated clutch slips and the next smaller pinion takes up the drive for a reduced speed or if the torque is still too great, the smallest pinion takes up the drive for low speed. When the torque decreases and /or when the speeds of the shafts 1 and 2 rise to increase the pressure of springs 7, the clutches of the higher speeds engage again and the lower speed pinions 15 freewheel on the shaft 2. Thus, the gear most suitable to the load and the speeds of the driving and driven shafts is automatically selected. Reverse gearing 19 is provided which is also adapted to give a neutral position. In a modification, a single centrifugal regulator only carried by the driving shaft is used so that the automatic selection depends upon the speed of the driving shaft only and the load. In this arrangement the driving and driven shafts are coaxial and the high-speed pinion 5 is directly connected to the driven shaft, the pinions 15 being mounted upon a countershaft.