SE366502B - - Google Patents

Abstract

1295060 Variable speed gearing SOC ANON AUTOMOBILES CITROEN 30 Dec 1969 [31 Dec 1968 10 Dec 1969] 63241/69 Heading F2D A vehicle gear-box 2 with n (e.g. four) forward ratios changed by relay means 4 (e.g. upchange and downchange relays 105, 106 to step a rotary switch 103) is controlled by an electronic device 1 comprising a generator 8 of a voltage signal U dependent on vehicle speed (e.g. by a tachogenerator) and the position of the accelerator pedal 11, (n - 1) upchange 12, 23, 34 and (n - 1) downchange circuits 43, 32, 21, all in parallel, and each having a detector for the signal U which triggers at a distinct voltage (different for each detector) to pass a signal (e.g. via an AND gate 14, 16 and an OR circuit 22, 27) to an output stage 25, 31 which thereby produces a pulse to change gear, there being in parallel with the circuits 12, 23, 34, 43, 32, 21, a manually controlled generator 6 to produce up and down change pulses manually (e.g. by moving a lever 7 down, f 1 , or up, f 2 ). Possible compositions of the various boxes are shown in schematic form (with capacitors, diodes, resistorsand capacitors) and some in block form in Figs. 2, 4 to 11 and 13 (not shown). The apparatus may include an illuminated indicator 195 showing which gear is engaged. It may be linked with the clutch 186 and/or the brake, Fig. 16 (not shown), by increasing the resistance between the tachogenerator 9 and the variable resistor 10. The device may include connections between the detectors of the upchange circuits and corresponding downchange circuits, Fig. 13 (not shown). The apparatus may include safety circuits (e.g. 29) to allow engine braking &c.