Patent GB-431941-A (GB)
Title: Improvements in gear shift mechanisms
IPC: F16H59/04
Filed: 1934-01-18
Abstract: 431,941. Controlling change-speed gearing. VAUXHALL MOTORS, Ltd., Kimpton Road, Luton, Bedfordshire, ROGERS, B. H., 28, Park Hill, Harpenden, Hertfordshire, and ASCOUGH, W. S., 111, Grosvenor Road, Westminster. Jan. 18, 1934, Nos. 1781 and 14966. [Classes 80 (ii) and 80 (iii)] Comprises gear-shift mechanism having an alternatively - pivotable shifter bar 26, the change of pivot being effected by movement of a separate locking plate 28. This pivot-changing movement of the plate 28 is longitudinal of the plate in the arrangement of Fig. 1 and transverse in the arrangement of Fig. 6. When the bar 26 pivots about its right end as seen in Fig. 2, a selector rod 12 on the left is moved ; when the bar 26 pivots about its left end, a rod 24 on the right is moved. A hand control lever 25, Fig. 1, fits in the shifter bar 26, passes down through a fixed gate 27 and through the plate 28 which has down-turned lugs at its ends adapted alternatively to engage up-turned lugs 29 on forks 11 and 23. The fork 23 is locked by the plate 28 so that the right end of the bar 26, Fig. 2, is a fixed pivot and the left end moves the rod 12 in two directions. To slide the plate 28 to change the pivot, the top of the lever 25 is turned through a right angle, thereby turning a lug 41, Fig. 1, which shifts the plate against return springs 47, Fig. 2. The application is described to the control of a relay-type gear box such as is described in Specification 403,422. Four speeds are effected by operating two front synchronized clutches 13, 16, Fig. 4, and two rear synchronized clutches 10, 10<1>. The rear clutches 10, 10<1> are connected by the fork 11, Fig. 3, to the rod 12, the means for operating which is described above. Changing the pivot as also described moves the rod 24, Figs. 2 and 4, and fork 23, to bring in an idler 20 for reverse. The front clutches 13, 16 are connected by forks 14, 17 to another pair of selector rods 15, 18, respectively. The rods 15, 18 are thrust forwardly of a vehicle or upwards of Fig. 2 alternatively as the lever 25 is moved transversely with the bar 26 sliding idly longitudinally of itself. The heel of the hand lever 25 engages a slot in a lever 30 the front free end of which engages, as shown in Fig. 8, over the rear arm 31 of a three-armed lever 31, 32, 33. Ball catches 36 provide that whichever of the arms 32 or 33 is swung forwards carries its rod 15 or 18 with it, the other rod being locked, so that the front clutches 13, 16, Fig. 4, are engaged alternatively. A ball 36, Fig. 8, is carried in an aperture in a sleeve 35 with which the lever arm 33 has sliding engagement. The sleeve 35 is loose on the rod 18 so long as the ball 36 projects idly into a groove 37 in the casing. As the sleeve 35 moves left of Fig. 8, the ball 36 rides out of the groove 37 and into a recess in the rod 18 which is thus locked to the sleeve 35 so that continued movement of the lever 33 carries the rod 18 with it. The other sleeve 34 is the same. At the change of pivot from the position of Figs. 1 and 2, when the rod 12 could be moved, to the other pivot position in which the rod 24 can be moved to bring in the reverse, the arm 33 moves forwards to engage the clutch 16 as is necessary for reversed driving. The four forward speeds are thus effected by moving the rod 12 in alternative directions and the rods 15, 18 alternatively by moving the hand lever in an H-slot, while, to bring in reverse, a twisting of the hand lever is necessary before moving into the appropriate gate slot. In the form shown in Figs. 6 and 7, the locking plate 28 turns on a horizontal pivot 51 and the change of pivot is effected by moving the hand lever 25 up and down of itself carrying the plate 28 with it. As shown in Fig. 6, the reversing fork 23 is locked and the rod 12 is free for endway movement in two directions. Transverse movement of the hand lever 25 through a bell-crank 57 operates the front clutches. A slot in the bell-crank 57 allows of the throw of the fork 23 after change of pivot to reverse. A stop 53 is provided to ensure that the clutch 16, Fig. 4, is engaged before the reverse idler 20 is moved to engagement. Specification 411,551 also is referred to.