Patent GB-405961-A (GB)
Title: Improvements in or relating to transmission gearing for self-propelled vehicles
IPC: F16H3/04
Filed: 1932-06-11
Abstract: 405,961. Change - speed gearing ; friction clutches. OLIVER, A. V., 12, Vicarage Road, Tottenham, London. June 11, 1932, No. 16615. [Class 80 (ii).] Change-speed gearing for vehicles comprises alternatively pre-selected friction clutches, the changes being effected by manipulating the engine throttle to cause back-drive from the road wheels to the engine. Each clutch comprises rollers, &c., 6a, Fig. 2, which jam so as to drive in both directions when a supporting cage 10 is free from constraint. The clutches are normally held disengaged by gapped control rings 16 feathered at 17 on outer clutch members 1a &c., which rings 16 by engaging lugs 13 on the cages 10 hold these cages in middle positions with the grip rollers 6a &c., in disengaged position. In a form of gearing shown in Fig. 1, the outer members 1, 1a, 1b of high, middle, and low-speed clutches are driven constantly at corresponding speeds from a driving- shaft 25. The member 1 is driven directly and the driven member 8 of the clutch is fast on a driven shaft 2. The middle speed outer clutch member 1a is driven from the member 1 through a constantly-revolving eccentricallysupported double gear wheel 3. The member 1b for the low speed is similarly driven through a double gear wheel 3a. The driven members 8a, 8b of these clutches are fast on the shaft 2. The rotary control rings 16 of the three friction clutches are moved axially by forks 20, 20a, 20b, Fig. 3, secured respectively to selector rods 19, 19a, 19b which are normally held at right by springs 18 so that the rings 16 are in the planes of the lugs 13 as shown in Fig. 1 in the case of the clutches 6a and 6b. These clutches are disengaged and are held so by the springs 18a and 18b. The clutch 6 as shown is engaged because the rod 19 has been thrust left against the spring 18 by the preselector so that the control ring 16 of that clutch has moved clear of the lugs 13 allowing the rollers 6 to be gripped by wedge recesses 5, Fig. 2. The preselection is done by a rod 24, Fig. 3, which slides across the ends of the selector bars 19, &c., and carries a roller 22 acted on by a spring 21 stronger than the springs 18. To change to middle speed, the roller 22 is moved over the bar 19a, compressing the spring 18a. The spring 18 returns the fork 20 to the right, carrying the gapped ring 16 towards the lugs 13, that is upwards of Fig. 4. The lugs 13 are intercepted and cannot pass through the gaps 15 until the throttle has been momentarily closed or " pumped." The lugs 13 of the middle-speed clutch 6a have hitherto been lodged in a long portion of a gap 15 as shown in Fig. 5. The actuation of the bar 19a tends to move the corresponding ring 16 downwards of Fig. 5. The lugs 13 however, engage shoulders in the gaps and cannot pass clear of the ring 16 until the throttle has been pumped as aforesaid. To engage reversed drive, a fourth rod 19c is pressed left by the preselector so that the power, instead of passing through the clutch 6b from the member 1b, passes through a reversing train 27, 28, 29, 30, 31.