Anti-skid brake system

Claim 3

A method of controlling the slip ratio of vehicle wheels according to claim 1, characterized in that said period of time is determined by the instant of the cycle when the speed of the faster rear wheel decreases to a first determined fraction of said stored speed, and that from this instant said time after which the rear wheels no longer tend to slip is determined by measuring the time elapsed between the instant when the speed of the faster rear wheel increases to a second determined fraction of said stored speed and the instant when the speed of the faster rear wheel increases to a third determined fraction of said stored speed, and then multiplying said measured time by a constant factor.

Claim 4

An anti-lock brake control device comprising an impulse sensor associated with each of said vehicle wheels; a first trigger for reshaping the impulses sent by said sensor associated with the faster rear wheel; a first clock furnishing an uninterrupted succession of impulses; a first digit counter adding said impulses of said first clock; a first store for storing the contents of said first counter when receiving an impulse from said trigger and through a first gate, said counter having a zero resetting input directly connected to output of said trigger; a second digit counter adding alternately the impulses of a second clock and of a third clock through a commutator actuated by a direct output and a complementary output of a first bistable of the flip-flop type responsive to trailing edges; a second store for storing the contents of said second counter when receiving a trigger impulse, said counter having a zero resetting input connected to said trigger output; a bit to bit comparaTor comparing the contents of first and second stores and taking, each time that the first store contents is lower than the second store contents, an active state, in which state said comparator delivers a long impulse to said first bistable, which changes over only when this impulse stops, and to an input of a second gate another input of which is connected to said direct output of first bistable and the output of which is connected to a second flip-flop bistable responsive to leading edges; an up and down counter, the up input of which collects impulses from a fourth clock through a third gate actuated by said complementary output of first bistable, and the down input of which collects impulses from a fifth clock through a fourth gate actuated by the output of a third bistable of the set-reset type, the set input of which is connected to said complementary output of first bistable and the output of which is activated by back return to zero, said output being connected through an inverter to reset inputs of second and third set-reset bistables and to set input of a fourth set-reset bistable, the reset input of which is connected to said trigger output and the output of which opens said first gate only when the vehicle brake command is actuated; first electromagnetic means actuated by output of said second bistable for interrupting the braking of the rear wheels; a second trigger for reshaping the impulses from said sensor associated with the slower front wheel; a third counter adding the impulses of a sixth clock; a third store for storing the contents of said third counter when receiving an impulse from said second trigger, said counter having a zero resetting input connected to the output of said second trigger; a second bit to bit comparator comparing the contents of said third store with the contents of said first store for generating a signal each time that the contents of third store is lower than the contents of first store; and second electromagnetic means actuated by said signal for interrupting the braking of the front wheels for the whole duration of said signal.

Claim 5

An anti-lock brake control device comprising an impulse sensor associated with each of said vehicle wheels; a first trigger for reshaping the impulses sent by said sensor associated with the faster rear wheel; a first clock furnishing an uninterrupted succession of impulses; a first digit counter adding said impulses of said first clock; a first store for storing the contents of said first counter when receiving an impulse from said trigger and through a first gate, said counter having a zero resetting input directly connected to output of said trigger; a second digit counter adding alternately the impulses of a second clock and of a third clock through a commutator actuated by a direct output and a complementary output of a first bistable of the flip-flop type responsive to trailing edges; a second store for storing the contents of said second counter when receiving a trigger impulse, said counter having a zero resetting input connected to said trigger output; a bit to bit comparaTor comparing the contents of first and second stores and taking, each time that the first store contents is lower than the second store contents, an active state, in which state said comparator delivers a long impulse to said first bistable, which changes over only when this impulse stops, and to an input of a second gate another input of which is connected to said direct output of first bistable and the output of which is connected to a second flip-flop bistable responsive to leading edges; an up and down counter, the up input of which collects impulses from a fourth clock through a third gate actuated by said complementary output of first bistable, and the down input of which collects impulses from a fifth clock through a fourth gate actuated by the output of a third bistable of the set-reset type, the set input of which is connected to said complementary output of first bistable and the output of which is activated by back return to zero, said output being connected through an inverter to reset inputs of second and third set-reset bistables and to set input of a fourth set-reset bistable, the reset input of which is connected to said trigger output and the output of which opens said first gate only when the vehicle brake command is actuated; first electromagnetic means actuated by output of said second bistable for interrupting the braking of the rear wheels; a second trigger for reshaping the impulses from said sensor associated with the slower front wheel; a third counter adding the impulses of a sixth clock; a third store for storing the contents of said third counter when receiving an impulse from said second trigger, said counter having a zero resetting input connected to the output of said second trigger; a second bit to bit comparator comparing the contents of said third store with the contents of said first store for generating a signal each time that the contents of third store is lower than the contents of first store; and second electromagnetic means actuated by said signal for interrupting the braking of the front wheels for the whole duration of said signal.