초록 ▼

Anti-skid brake control systems are described in which anti-skid brake control modules associated with the braked axles are each provided with a failsafe circuit and these failsafe circuits are connected in cascade fashion to form a chain so that an input signal applied to a first failsafe circuit w

Anti-skid brake control systems are described in which anti-skid brake control modules associated with the braked axles are each provided with a failsafe circuit and these failsafe circuits are connected in cascade fashion to form a chain so that an input signal applied to a first failsafe circuit will propagate through the chain of failsafe circuits to the output of the last failsafe circuit only if the wiring connecting the modules is correct, the failsafe circuits are themselves operating correctly and electrical power is being supplied to each module, a warning being given to the driver of the vehicle if the output signal from the last failsafe circuit fails. In a previously proposed system the warning given is only produced in the event of a fault, and there is no positive indication of correct operation of the system at switch on. Circuits are here described in which the vehicle ignition switch is arranged to apply a fault pulse to the input of the first failsafe circuit in the chain at switch-on of the ignition and the response of the output of the last failsafe circuit to the pulse is monitored by a suitable monitor unit. Some of the failsafe circuits incorporate switch-off circuits which are so arranged that, on the occurence of a fault in the chain upstream of that failsafe circuit, the switch-off circuits operate an inhibit device to inhibit operation of one or more of the brake release circuits which are downstream of the point at which the fault exists.

대표청구항 ▼

A multi-axle wheeled vehicle comprising a respective brake for each axle, a respective speed sensor associated with each axle, a respective brake release means associated with each axle and responsive to the respective speed sensor to release the respective brake on the occurrence of a skid conditio

A multi-axle wheeled vehicle comprising a respective brake for each axle, a respective speed sensor associated with each axle, a respective brake release means associated with each axle and responsive to the respective speed sensor to release the respective brake on the occurrence of a skid condition at that axle, a respective inhibit means associated with each brake release means and being operable by inhibit operation of that brake release means, a respective fault detection circuit associated with each brake release means and being responsive to a fault condition in that brake release means to operate the respective inhibit means so as to inhibit operation of the associated brake release means, a respective signal repeater circuit associated with each brake release means and having an input and an output, means connecting the inputs and outputs of the signal repeater circuits in series to form a chain so that a signal applied to the input of the first repeater circuit in said chain will normally be propagated along said chain to the output of the last repeater circuit in said chain, each signal repeater circuit being responsive to the respective fault detection circuit so as to interrupt the passage of said signal along said chain upon the occurrence of said fault condition, and a respective shutdown connection means associated with each inhibit means and for optional connection to the input of the respective signal repeater circuit so that, when connected, an interruption in said signal at said input due to a fault upstream thereof along said chain causes said inhibit means to be operated to inhibit operation of the associated brake release means, whereby in the event of said fault condition occurring in one of said brake release means, operation of selected brake release means downstream thereof is inhibited.