Patent GB-668951-A (GB)
Title: Automatic means for selective operation of change speed gears, particularly for motor cars
IPC: F16H61/02
Filed: 1950-02-22
Abstract: 668,951. Variable-speed gearing. MASSAROTTI, M. Feb. 22, 1950 [Jan. 23, 1950], No. 4536/50. Class 80 (ii). In a motor vehicle, a cam 10 is turned through rack-and-pinion gearing 6 by speed-responsive means 2 so as automatically to preselect an appropriate gear, engagement of which is effected by double operation of a lever 37, the first operation of which disengages the previously-engaged gear and the subsequent return movement of which positions the mechanism for engagement of the preselected gear on the second operation of the lever, the subsequent return movement of which positions the mechanism for disengagement of that gear on the next operation of the lever. Opposed rollers 12, 14, carried by levers 16, 28, co-operate with the cam 10. The lever 16 acts, through a bell-crank lever 20, to move an arm 24 laterally into engagement with the appropriate selector bar 26. Lever 28 carries a pin 30 engaging a slot in a member 34 pivoted on one arm of the lever 37, the other arm of which has a lost-motion connection, via a rod 58, with the main clutch pedal 70. The member 34 has lugs 38, 40 co-operating with pins 42, 44, 46, 48 on a rotatable disc 50 which, via rod 52, crank 54 and arm 24, is adapted to move the selected bar 26 longitudinally. An extension 60 of the member 34 is guided between a pair of rollers 62 carried by a plate 64 which is rotatable about the axis of the disc 50, the plate being connected to the disc by a pair of springs 66, 68. The cam 10 may be turned by hand from a lever 82, via Bowden mechanism 80 and a lever 78 engaging a notch in the cam, for neutral position S, reverse R, or first gear A. Each lever 16 or 28 is divided and hinged on its fulcrum, the two parts being resiliently connected by a pair of springs. With the parts initially in neutral position as shown in Fig. 1, in which the lugs 38, 40 are clear of all the pins so that depression of the pedal 70 has no effect on the gear mechanism, movement of lever 82 to position A turns the cam 10 clockwise so that arm 24 is moved laterally to engage the first-speed bar 26 and member 34 is turned anticlockwise to bring the lug 40 in front of the pin 42. On depressing the pedal 70, the main clutch is first disengaged, and then member 34 is moved longitudinally to the left, the extension 60 riding under the lower one of a pair of fixed rollers 88, so that lug 40 acts on pin 42 to turn disc 50 clockwise, thereby causing arm 24 to move bar 26 longitudinally to engage first gear. On releasing pedal 70, main clutch engages and member 34 moves to the right. As extension 60 moves off the roller 88, the springs 66, 68 cause the member 34 to tilt clockwise so that lug 38 comes in front of pin 46. On now depressing pedal 70, lug 38 coacts with pin 46 to turn disc 50 clockwise, thereby disengaging first gear. If, in the meantime, the vehicle speed has increased sufficiently as to turn cam 10 to preselect second speed, the member 34 is turned clockwise to bring lug 38 in front of pin 48, on release of the pedal. On again depressing the pedal, see Fig. 3, the disc 50 is turned anti-clockwise to engage second gear, the extension 60 riding on the upper roller 88. On return of the pedal, member 34 is tilted anti-clockwise by the springs 66, 68 so that lug 40 is adjacent pin 44, ready for disengagement of the gear on the next depression of the pedal. Signal lamps may be fitted to show which gear is engaged and which is preselected. Instead of the lever 37 being coupled to the clutch pedal 70, it may be operated automatically by the speed-responsive means.