GB244583A - Improvements in or relating to gear-changing apparatus - Google Patents

Abstract

244,583. Ruck, Sir R. M. Dec. 12, 1924. Controlling variable-speed gearing for use on vehicles of the kind referred to in Specifications 112,480 and 187,317. To the main slide 31, Figs. 1 and 8, of this apparatus is secured a cam plate 100, which through levers 94, 95, 90, 91, Fig. 14, actuates selector bars 88, 89 opernting the change-speed gear 87. The gear-operating shaft 21 carries a pair of face-cams 32, 33, Fig. 1, adapted to be engaged by rollers 44, 45 upon pawls 36, 37, Fig. 6, which when allowed to drop engage recesses 48, 49 in the slider 31. Thus at each revolution of the shaft 21 the slider 31 is moved a step to left or right according to which of the face-cams is rendered operative. There is an arrangement of abutments 130, 131, Fig. 2, lever 133, and crank 137, Fig. 6, by which main clutch is disengaged prior to each speed change. The pawls 36, 37 are strained towards depression by a spring 42, Fig. 4, and there are timing cams 62, 63, 64, Fig. 1, acted on by timing levers 58, 59, Fig. 4, which are normally locked by spring levers 50, 51. These locking levers are disengaged alternatively to actuate the slide 31 one way or the other by power, and this is done by a sliding tappet rod 68, controlled through linkwork 76, 77 from a hand lever 78, Fig. 12, upon the steering column. In order to prevent too many power-actuated operations in succession, cams 121 - - 124, Fig. 8, are provided on the plate 100 which through a linkage 119, 75, Fig. 14, returns the lever 78 to mid-position after each single shift is accomplished. The plate 100 is connected directly by a link 110 to a hand lever 108, Fig. 12, the position of which shows the gear ratio in action. The lever 108 provides means for alternatively shifting the plate 100 manually. The plate 100 is locked in gear positions by recesses 103 engaged by a spring jumper 102, Fig. 1, and is locked positively in addition by a pin 104 which is released for power shifting by the timing levers. For manual operation, the pin 104 is adapted to be disengaged from a finger lever 113, Fig. 12. To facilitate gear change, each of the selector bars 88, 89 is fitted with a push and pull elastic coupling 126, Fig. 13. A modification is shown in Figs. 16 and 17. There is an inner pillar 140 secured to a spring control lever 142 and an outer pillar 144 secured to a quadrant 143 and connected by a linkage 162, 164 so as to move the plate 100 directly. Thus when a locking pin 171 upon the lever 142 engages a hole in the quadrant 143, the inner and outer pillars are locked and gear change can be effected manually. For power actuation, a lever 155 is allowed to drop, which through an eccentric depresses a catch 147 which clutches the pillar 140 to a cam sector 146. The lever 142 is displaced over the quadrant 143 and then locked thereto, engagement being effected by a spring 142<a>. The cam 146 follows the lever 142 with the result that the tappet rod 68 is moved, locking lever 50 or 51 is disengaged, and the camming forward or backward of the slider 31 commenced. The slider 31 turns the outer pillar 144 so as to bring the lever 142 back to its initial position, the quadrant 143 having been moved. Specifications 145,890 and 146,548, [both in Class 4, Aeronautics], are also referred to.