Abstract:
A monitoring and protecting device for an antiskid functional circuit assembly responsive to the variations in one or more electrical input signals and supplying at least one output signal in response to given values of the variations, the device comprising filter means, a summation means, a threshold means, and at least one blocking element, arranged in that order. Each filter means being supplied by one input signal and passing given fraction of this signal. The summation means supply the threshold means with the sum of this fractions, for blocking transmission to the assembly of at least one input signal when the sum is greater than or equal to a given threshold.
Abstract:
Monitoring circuit for an electronic system such as an adaptive vehicle braking system, in which at least one signal processing chain has an input connected to a source of signals having a variable frequency. A switch is periodically controlled to the conducting state to connect the input of the signal processing chain to ground, thus producing a disturbance which is felt as a sharp decrease in the frequency of the input signal representative of a decrease of the wheel speed in the case of an adaptive braking system. Simultaneously, a delayed action warning device is energized, the operation of this device being delayed by a time longer than the response time of the chain. If the system is in good operating condition the utilization device connected to the output of the processing chain will receive a control signal. This signal is used for resetting the switch and for stopping the energization of the delayed action warning device. In the occurrence of a failure, the control signal will not be received and the warning device will trigger an alarm.
Abstract:
The servomotor comprises a boost piston whose movements depend on the pressure of fluid contained in an actuating chamber, said pressure being controlled by a distributing valve connected to a pressure fluid source and to a reservoir. The valve is operated by a push rod through the intermediary of a lever assembly responsive to the relative movement of the push rod and of the boost piston. The push rod, mounted coaxially to said boost piston, projects therein. The projecting end contains a helical groove whose top cooperates slidably with the surface of a cylindrical bore formed in the boost piston.
Abstract:
A fluid pressure unbalance indicator comprising two separate pistons respectively subjected to forces created by the pressure prevailing in two independent fluid circuits, the pistons acting in opposition to one another and being mounted in a housing so as to move in conjunction with one another and to operate electrical contact members under the influence of a pressure difference which denotes failure of one of the fluid circuits and which produces a force capable of overcoming the force of a resilient system associated with the pistons. In the invention, the resilient system is situated in a region of the housing accessible to both pistons, and each end of the resilient system bears on a fixed portion of the housing and is engageable by the piston subjected to the higher of the fluid pressure forces.
Abstract:
An electronic antiskid braking system of the type using a speed reference signal having a maximum rate of decrease as established, furnished by the constant current discharge of a capacitor in a circuit, is disclosed. The maximum slippage which is tolerated by the wheel includes a constant quantity which is determined by a potentiometer, and includes too a variable quantity, which is obtained from the direct voltage-drop in a diode. A switching device controlled by the first occuring pressure reducing signal of an antiskid braking operation, is provided to modify the intervention threshold during the initial adaptive braking cycle.
Abstract:
A disc brake comprising a sliding caliper straddling the disc and supported on two axially extending pins mounted in a fixed support, two pressure pads anchored on the fixed support so as to co-operate with the opposite sides of the disc, one pad being adjacent to an inside surface of one leg of the caliper, the other pad being operated by the piston of a brake cylinder mounted in the other leg of the caliper, the pins traversing mutually opposite bores axially provided in the support and in the caliper to guide the sliding movement of the caliper, wherein said bores are open along their length to have a substantially Cshaped cross-section, so that the pins can be introduced into the bores through the opening, locking means being also provided, so that the pins cannot thereafter freely escape from the bores by passing through the opening.
Abstract:
A voltage converter set designed to feed an antiskid logic element and to modify the wheel speed sensor signals. The converter set includes a proportional converter and an inversely proportional converter, connected through a diode, so that the output voltage of the converter set is higher for the low wheel speeds. The invention also provides the combination of several converter sets with a single antiskid logic element in a circuit of the exclusive ''''OR'''' or ''''SELECT LOW'''' type.
Abstract:
Spring brake actuator having a manual release mechanism. In this actuator, the push-rod is slidably received through an opening in the piston, the piston being connected to the push-rod by a bayonet type locking means in which members can be engaged with one another by rotating the push-rod in one direction. A telescopic connection arranged rearwardly of the piston includes a control member manually operable from the exterior of the actuator housing for rotating the push-rod in the other direction to thereby dissociate the push-rod from the piston and cancel the braking action of the actuator. The push-rod is rotationally urged in the locking direction by a spring for allowing the actuator to be automatically reset when its supply in fluid pressure is restored.
Abstract:
The invention relates to a pneumatic antiskid braking system for vehicles equipped with pneumatic power assistance. An exhaust valve designed to connect the motor chamber of a brake motor to the atmosphere is controlled on the one hand by a piston submitted to motor pressure differential between the two opposite chambers of the brake motor, and on the other hand by a control submitted to the opposed efforts provided by a preloaded spring and by a pilot pressure controlled by a valve operatively actuated by the antiskid control unit.
Abstract:
An electronic anti-skid device for a vehicle braking system, operative upon actuation of the brake pedal to periodically apply the brakes and isolate the braking system from the brake pedal under the control of signals representative of the wheel acceleration. During the periods when the braking system is isolated, the wheel acceleration curve comprises a negative portion followed by a positive portion having a peak value. With this device, the periods when the braking system is isolated are ending shortly after the wheel acceleration has reached its peak value. This is obtained by comparing the positive portion of the acceleration signal with the output signal of a time-constant circuit having a discharge curve which intersects the acceleration curve in the neighborhood of the peak value.