GB1224832A - Gear selector mechanism - Google Patents

Abstract

1,224,832. Change-Speed control. BRITISH MOTOR CORP. Ltd. 14 Jan., 1970 [28 Jan., 1969; 6 Aug., 1969], Nos. 4573/69 and 39270/69. Heading F2D. In a layshaft type manual C.S.G. in which at least four forward speeds and one reverse are controlled by a ball-mounted lever 6 having its lower end engaging a cranked arm of a turn-and-slide shift rod 7, two or more striker forks 2, 3 being selectively axially movable along a common rail 4 for lst/2nd and 3rd/4th ratios respectively, at least two non-coplaner pins 10, 11 rigidly fixed to and projecting from the shift rod 7 are each arranged, in neutral, to lie in the same radial plane as a co-operating notch 12, 13 in the corresponding striker forks 2, 3 whereby gear-establishing axial movement of the shift rod 7 can only take place when one of the pins 10 and 11 lies within the notch of the relevant striker fork for forward ratio establishment, or when the pin 10 enters a notch 14 in a reverse establishing lever 15 (Fig. 4), a sleeve-like interlock bobbin 17 mounted coaxially on the shift rod 7 and slotted for rotary engagement therewith via the pins 10, 11, being permanently locked against axial displacement by a plate 21 engaging one (19) of a pair of collars 18, 19 on the bobbin 17, which collars, in neutral, lie within the corresponding notches of the striker forks whereby during gearselecting movements, the non-selected striker forks and/or reverse establishing levers are locked in their neutral positions such that only one fork 2 or 3 or the lever 15 can be moved from the neutral position at a time. A 5thspeed striker fork may be incorporated in the arrangement, a third pin being added to the shift rod together with its own short interlocking bobbin or on extension of the interlock bobbin 17. As shown, the striker forks are slidable on the common fixed rail 4 or, alternatively, Fig. 11 (not shown), one striker (3) is slidable on the rail, the other striker (2) being fixed at (26) thereon and slidable jointly with the rail in the gearbox casing, thereby reducing the effort required to move the striker 2, viz. the span resisting the couple loading on the striker fork 2 is increased whereby the reaction loads and hence friction resistance to movement are reduced, the effort required to move the striker 3 remaining unchanged as before.