GB292445A - Improvements in and relating to variable speed gears - Google Patents

Abstract

292,445. Furness, J. A. Dec. 23, 1926. Variable-speed epicyclic gearing of the kind comprising a solid-driving clutch such as 16, Fig. 2, and brakes such as 29 - - 32 for effecting other drives is controlled by selector means involving spring means such as plunger 23, Fig. 1, for holding in action a selected brake or clutch. To change speed, a pedal 21 is depressed which acting through arm 19 turns selector means such as rod 5 against the spring plunger 23 to disconnect the drive. A selector lever 1 is manipulated to bring one of a number of cams 6, 7 over a selected brake or clutch lever 8, 9, 10, 11, or 12. Upon release of the pedal, the selected speed becomes operative. In Figs. 5 and 6 is shown a form of the invention adapted to the changespeed gear described in Specification 276,405. The drive-engaging spring 91 acts to thrust down. wards a pivoted slotted plate 89. There are cams 44, 47, 48 for operating the gear brakes 53 and selector fingers 43, 45, 46 which are suitably operated. In the arrangement shown, these cams and fingers are carried by rods 41, 42 which are slid selectively from a hand gate control 35 so that on release of disengaging pedal 71 the spring 91 makes selected gear operative. If the plate 89 in its descent misses the fingers 43, 45, 46, it moves far enough to operate a lever 75 which has a cam face 80 which brings into action the clutch 84, which locks the gearing solid for that drive. The fingers and cams are so arranged that the plate 89 alternatively engages one finger at a time and so turns the cam rods 41, 42 one at a time so as to operate the brakes 53 singly as required. A neutral results when the finger 43 is over a fixed projection 96 on the gear case and under a tenon 93 on the plate 89, which is thus prevented from descending. Each brake comprises two half-circle shoes simultaneously applied.