GB189804354A - Improvements in Mechanical Variable Speed and Reversing Power Transmitter. - Google Patents

Abstract

4354. Altham, G. J. Feb. 22. Motor road vehicles.-Relates to variable-speed and reversing power - transmitting mechanism principally designed for use on vehicles propelled by oil or gas motors. The gear is of such construction as to permit the desired changes in speed and direction to be effected while the motion still runs on continuously and uniformly in the same direction. In the improved mechanism the power is transmitted through the medium of a series of intermittently-acting friction roller clutches, which have an oscillating movement, and the variation in speed is brought about by making the successive engagements of the clutches last a longer or shorter time as the case may be by varying the amplitude of their movement. (1) Two forms of the invention are shown ; of which one is seen in side elevation in Fig. 1. In this gear, motion is to be transmitted from the uniformly-driven shaft a to the shaft b, or vice versÔ, through the medium of clutch mechanism contained in the loose drum c. Figs. 6 and 8 show respectively longitudinal and transverse sections through this drum. On the shaft a is loosely mounted a sleeve a' which is embraced by a series of six friction roller clutches g. These have arms by which they can be rocked, through the linkage shown in Fig. 8, from a crank d<2> at the end of the driving-shaft a. In order to enable the stroke or amplitude of movement of the clutches to be varied, and so to regulate the speed of the sleeve a', the throw of the crank d<2> is made variable. An increase or decrease, as required, in the throw of the crank-pin is effected, whether the gear is in motion or not, through the medium of screw gear operated by a friction drum f which can be put into action by a rod f<10> and suitable connections. For forward driving, whatever the speed as determined by the throw of the crank d<2>, the sleeve a' is held stationary by the brake arrangement l shown in Fig. 1, and motion is communicated to the shaft b by a toothed wheel h carried by the drum c. For reverse driving, the sleeve a<1> is released, but the drum is allowed to remain in gear with the shaft b. From the sleeve a' motion is communicated through chain gear to a friction-wheel n<3> which is made to frictionally engage with the wheel on the shaft b whenever the sleeve a<1> is released. By this means a slow reverse motion is given to the shaft b. (2) The second form of the invention is shown in Fig. 18. In this the linkage and clutch gear by which motion is to be conveyed from the driving-shaft o to the shaft q is contained in a stationary casing instead of in a rotatory drum. The crank-wheel p<2> from which the oscillation of the clutches is derived is mounted at the end of an adjustable hand-lever p<7>. By adjusting this lever, the throw of the clutches, and therefore the speed of the shaft q, can be regulated.