Patent GB-387246-A (GB)
Title: Automatic, continuously variable gears
IPC: F16H29/14
Filed: 1932-07-28
Abstract: 387,246. Variable - speed gearing ; cams. AKTIEBOLAGET RADIUS, Tellusborg, and RAFTING, E., 7, Vanadisvõgen, both in Stockholm. July 28, 1932, No. 21336. Convention date, July 29, 1931. [Classes 80 (ii) and 80 (iii).] A speed gear automatically variable jointly by the rotational speed of the driving-member and the load on the driven shaft comprises planet pinions 6, Fig. 1, or equivalent cranks 58, Fig. 19, which drive with varying amounts of lost motion by releasable planetary clutches under the control of a non-rotary adjustable central eccentric 26. The planets 6, Fig. 1, are fast on spindles 4 supported in a driving flywheel 3 and mesh with a sun gear 7 fast on a driven shaft 2. Loose on each spindle 4 is an eccentric 13 which can be locked to the gear 6 by a spring coil clutch 18. Loose on the eccentric 13 is a coned bowl 15 adapted to engage the coned eccentric 26. The eccentric 26 slides on inclined keys 25 on an oblique barrel 24 integral with a fixed sleeve 10. The coil 18 is connected by links 21, 20, Fig. 2, to a clutch-releasing drum 22 which engages the resilient periphery of a non-revoluble central cam 32, Fig. 1. This cam is formed, as shown in Fig. 1a, with superposed resilient peripheral strips 37 connected by staggered supports 38. The cam 32 is held by a central spring 36, Fig. 1, with an abutment 33 pressed against the eccentric 26, which is thus held pressed against the thrust ring 31 of a control device depending on speed. This consists of pivoted centrifugal weights 28, which tend to thrust the eccentric 26 to the left and are always in balance with the load reaction, which acts through the coned surfaces of the members 15, 26 in the opposite axial direction on the eccentric 26. In the position shown, the eccentric 13 is not prevented from turning freely, because, in turning, the increasing radius of the eccentric 13 corresponds to the decreasing radius of the eccentric 26. There is therefore no drive. On increased engine speed, the weights 28 thrust the eccentric to the left to a more central position in which its eccentricity is less than that of the eccentric 13. The free inward swing of the eccentric 13 is thus curtailed, with the result that there is a lock for a part revolution and an impulse is transmitted through the coil 18 and planet 6 to the driven sun 7. As the control eccentric 26 approaches the gear axis, the speed of the driven shaft 2 increases. In its central position, the eccentric 26 wholly prevents the eccentric 13 from turning on its spindle. At the same time, the cam 32 slips clear of the releasing drum 22, so that the coil 18 is never released, and a high-speed solid drive results. Fig. 7 shows a more elaborate form with a main clutch 115 between the engine shaft 1 and the casing 3 which carries the toothed planets 6. The non- rotary control eccentric 26 is cylindrical and is engaged by wiping levers 86 integral with the loose members 84 of the releasable clutches 18, which are released by a cam 106. The torque reaction, which is balanced against the centrifugal pull of the weights 28, is exerted through a helical sleeve 91 between the sungear shaft 75 and a tail shaft 2. The control eccentric 26 is slid at right-angles to the fixed sleeve 10 by inclined keys 88, and a spring 98 acts through a bearing 95 to hold the keys 88 at left with the eccentric 26 in extreme eccentric position, which effects the lowest speed, a definite one-third ratio, Reversed driving is effected by sliding a gear 116 splined on the fixed sleeve 10 into mesh with companion planets 114. The crank linkage form is shown in Fig. 19 schematically and in part only.