Abstract: Wear warning device for indicating wear in brake lining and drum in drum brakes for motor vehicles with automatic brake adjustment. In a drum brake with a lifter and adjustment devices (5), comprising an internally threaded lifter head (7) and a lifter screw (8) screwed therein, the wear warning device comprises a switch (20) supported by the lifter head, the switch having an axially displaceable pin (22) in contact with the thread of the screw (8). the screw is provided at its distal end with a depression (26) in the thread. When the pin moves down into the depression, the circuit in the switch is closed in order to activate a warning device.

Abstract: A computer based parking brake detection and warning system and method includes pressure sensors for sensing a pressure in a parking brake line to detect that a parking brake has been activated. The computer waits a predetermined period of time after detecting that the parking brake has been activated. The system determines parking brake warning levels based on the speed of the vehicle, detecting the activation of the parking brake, and based upon whether power has been requested by an operator. The system activates a visual and audible alarm in response to the determining of a warning level when the speed is above or below a predetermined threshold. Multiple levels of warning levels are used depending upon the speed of the vehicle.

Abstract: An electronic brake pedal adjustment apparatus has an apparatus for setting braking characteristics by which the driver can enter the relationship between the desired brake fluid pressure with respect to a given brake pedal effort, a detector for detecting an actual brake pedal pressure; and a computer for calculating a desired brake fluid pressure based on the set braking characteristics for the detected brake pedal effort. A brake fluid pressure control device is also provided so as to make the actual brake fluid pressure commensurate with the calculated brake fluid pressure. The relationship between the desired brake fluid pressure and the given brake pedal effort is shown on a display.

Abstract: The brake monitoring system of the present invention monitors and measures brake adjustment and brake lining wear in vehicles employing air brakes having an "S-Cam" assembly. The S-Cam is actuated by an pneumatically driven push-rod, which rotates a cam shaft on which the S-Cam is mounted by moving a slack adjuster lever mounted on an opposed end of the cam shaft. The S-Cam forces a pair of opposed brake shoes against the interior surface of a brake drum. Rotation of the S-Cam is measured with each application of the brakes and converted into a readout of the adjustment of the brake's adjustment and brake wear which is displayed in the vehicle cab.

Abstract: An automatic slack adjuster or manual slack adjuster conversion which automatically adjusts the brakes incorporating a monitoring system that monitors the operation and adjustment of air powered brakes as used on vehicles. The system monitors the travel of the brake components, and when needed uses electromagnetic or pneumatic power to provide adjustment of the vehicle's brakes. Using groups of visual indicators to create a visual dashboard display of all brakes on the vehicle, the driver is provided with immediate and accurate brake operation and adjustment information. The visual indicators are controlled by multi-range position detectors that are incorporated into the automatic slack adjuster or conversion unit. Each position of the multi-range position detector activates an individual visual indicator providing precise range of adjustment indications each time the brakes are applied.

Abstract: An anti-skid control circuit for a wheeled vehicle has a connector (15) for connection to external circuits and a warning circuit contained within the control circuit and connector (15) for enabling a visual indicator (17) upon the occurrence of a loss of power to the anti-skid control circuit, a malfunction of the anti-skid control circuit, or disconnection of the connector (15) from the anti-skid control circuit. The anti-skid braking system warning circuit includes an electrically energizable the visual indicator (17) in the form of a lamp (17), and a first transistor (33) connected in series with a source of electrical energy. A control transistor (35) is conductive to shunt the base-emitter circuit of the first transistor (33) so long as the anti-skid braking system functions properly. When the control transistor (35) becomes nonconductive indicating a lack of the anti-skid function, the base-emitter circuit of the first transistor (33) is forward biased and the lamp (17) energizes.

Abstract: A warning system alerts a driver of a motor vehicle to different types of traction losses. A first sensing circuit (10) detects a loss of wheel adhesion by monitoring a vehicle drive line for a pronounced vibration within a range of between ten and fifteen hertz. A second sensing circuit (12) monitors a brake light circuit to detect application of a vehicle brake. A logic circuit (28) combines outputs (A and B) from the first and second sensing circuits and outputs command signals (C and D) that distinguish between a loss of wheel adhesion due to wheel skidding and a loss of wheel adhesion due to wheel slipping. A warning device includes two indicators (36 and 38) that receive the respective command signals and produce sensorially distinguishable warning signals for eliciting different responses from the driver.

Abstract: An apparatus for monitoring brake condition for an air actuated diaphragm spring brake actuator provides a visual or audible signal when brake wear causes a brake push rod to move past a pre-determined distance with respect to the brake actuator housing. The indicator includes an engaging mechanism to retain the indicator in its operative position irrespective of subsequent movement of the push rod. A continuous record of brake failure or serious brake wear or misalignment is thereby provided.

Abstract: A method for the surveillance of a brake device includes an indirect measurement of temperature of a selected device component, for example a brake drum, of a brake device. A warning signal is furnished, if this measured temperature reaches a maximum permissible value. The invention method is quick by employing the pressure-dependent deformation characterizing curve (11) of the device component heated to the permissible temperature. The device component represented by the brake drum (1) can heat to the maximum permissible temperature and is placed under surveillance during a brake actuation based on deformation and pressure measurement. It is then determined if the actual values reach or exceed the deformation characterizing curve (11). The invention apparatus is used in connection with brake devices in vehicles.

Abstract: The wear indicator of the friction lining (10) of a brake consists essentially of a loop of conductive wire arranged in a sleeve (18) closed by way of an insulating bush (20) of cylindrical form and having a longitudinal axis (16). The loop is in contact at least once with substantially all the generatrices of the inner wall of the bush (20). Preferrably, the loop consists of a substantially straight first part (24) arranged parallel to the longitudinal axis (16) and a second part (26) wound helically round the first part (24) and connected to the latter.

Abstract: An overload warning system for a trailer brake cylinder of a trailer brake system having a nominal deceleration rate. It has been found that previous temperature sensing overdue warning systems have a disadvantage that undue delay occurs and that no warning signal is initiated until after damage to the trailer brakes occurs. The present invention proposes that the tractor brake system and the trailer brake system compare their received operating control signals from which they form a ratio factor and then produce a warning signal when the ratio factor changes beyond a predetermined critical change velocity. The present invention employs the rapid drop in braking force caused by a brake overload and uses the rapid drop and increase brake demand for readjusting the brake deceleration. The present invention is used for uniquely recognizing the "Fading" effect of the trailer brake system.

Abstract: An analyzing and fault indicating system for automatic transmissions and their related electro-mechanical operating functions, including vacuum pressure and/or fluid pressure and/or governor and/or computer controlled electrical circuits on automotive vehicles so equipped. This system inserts a passive electron flow measuring ampere meter in series with, and continuously monitors the transmission's principal solenoid winding, called a torque converter clutch (T.C.C.) solenoid, for manufacturers specified quantity of electron flow for satisfactory solenoid operation. Contained in an apparatus case are the system's lamps, light emitting diodes and an ammeter which functions to indicate faults or satisfactory operation of the automatic transmission and/or related function controls. The apparatus case is mechanically suspended from the in-vehicle rear view mirror or its immediate vicinity and connected by two cables to the automatic transmission.

Abstract: The short-circuit and ground fault detecting apparatus for automotive electromagnetic clutches consists of a clutch current calculating device, a clutch current control device, and a clutchoutput cir;cuit operation detecting device. The clutch current control device has two output transistors on the positive and negative side of the clutch, serving as switches connected to current supply mechanisms of the magnetic clutch. The magnetic clutch is energized and deenergized by turning on and off the output transistors. The voltages at the output transistors are sent to the clutch output circuit operation detecting device, where they are removed of ripples and converted into digital signals and then fed back to the clutch current calculating device, which in turn checks the digitized voltages for any fault.

Abstract: A method for the approximate determination of the average temperature of a device component of a brake device. The average temperature is determined by the deformation of the device component at the start of a brake actuation and at a point in time t.sub.1 following said start as well as by a temperature-dependent change of the elasticity module of the material of the device component. The method is particularly useful for surveillance of brake devices of vehicles with respect to overloading and fading.

Abstract: An apparatus for diagnosing a fault of a hydraulic pressure source, including a fluid tank, a pump for pumping up fluid from the fluid tank, an accumulator for accumulating the fluid pumped up by the pump, a pressure detector for detecting a pressure of the fluid in the accumulator and generating an output signal, a pump drive or motor responsive to the output signal for driving the pump, and an electromagnetic valve of normally closed type interposed either in a flow path between the accumulator and a hydraulic pressure instrument or in a flow path between the tank and the hydraulic pressure instrument. This apparatus comprises an excitation signal generator for generating an excitation signal which excites the electromagnetic valve for a predetermined period of time, and a control unit for determing an anomaly on the basis of the output signal from the pressure detector. If any fault exists in the hydraulic pressure source, fall and rise of the hydraulic pressure is not effected normally.

Abstract: A brake pedal travel warning system for use in an automotive vehicle includes a brake pedal and a master cylinder associated with the brake pedal through a connecting link. The master cylinder includes a fluid reservoir containing brake fluid and a housing including an internal bore communicating with the fluid reservoir through a reservoir port, the bore defining a primary chamber and a second chamber. A primary piston is slidably disposed in a primary chamber and reciprocally moves therein. A secondary piston is slidably disposed in the secondary chamber. The master cylinder further includes a signal generation means associated with the primary piston for generating a warning signal in response to excessive piston travel in the primary chamber.

Abstract: A vehicle brake has a fixed backplate carrying a pair of friction elements and an actuator operable to urge the elements into braking engagement with a rotary braking surface. An abutment for the elements has a portion which is deflectable by load on the elements arising from braking torque. A radiation input device directs radiation at a surface of the deflectable portion and a device is provided to sense radiation after its impingement on the portion and to transmit the sensed radiation to a device producing a responsive electrical output representing deflections of the portion.

Abstract: A brake monitoring system for a motorized vehicle having fluid brakes including a pressurized fluid chamber and brake engaging apparatus. Sensors are provided to measure the required fluid pressure exerted by the fluid chamber on the engaging apparatus to bring about braking of the vehicle. Measurement is also made of the distance the engaging apparatus is extended from the fluid chamber in braking. Apparatus is further provided to determine from the measured fluid pressure and measured engaging distance whether the brakes are properly adjusted.

Abstract: A warning device for detecting mineral oil impurities in the brake fluid of hydraulic vehicle brake systems is described. The warning device comprises a body which is arranged in the brake fluid and can swell as a result of mineral oil and the change of shape of which indicates the presence of mineral oil impurities. The indication is given particularly as a result of the fact that the change in shape brought about by the swelling causes the opening or closing of an electrical circuit and thereby actuates a visual or acoustic indicator in the dashboard of the vehicle.

Abstract: A system for displaying trouble in an electronic control system such as an anti-skid brake system of a motor vehicle. The system has a detector for detecting failure in a wheel speed sensor, and a warning lamp for displaying a detected failure. When a failure in the sensor is displayed on the lamp, an inspector depresses a brake pedal of the vehicle in accordance with a predetermined pattern to intermittently turn on a brake pedal switch to produce a failure signal representing the nature of the detected failure. In response to the failure signal, the warning lamp intermittently lights up in accordance with a predetermined pattern representing the nature of the failure.

Abstract: An electrical switch operated by the input member of a hydraulic master cylinder and controlling the stop signal lights of a motor vehicle, when associated with the master cylinder of a hydraulic brake system, and/or controlling a cruise control disconnect circuit. When associated with the master cylinder of a clutch hydraulic control system, the switch is adapted to close an interlock circuit allowing the motor vehicle driver to start the engine only when the clutch is fully released, and to operate a cruise control disconnect circuit upon small displacement of the input member from its home position.

Abstract: A gas leakage detecting device for detecting leakage of a precharged gas from a gas-type accumulator which is connected to a hydraulic pump and which stores a pressurized hydraulic fluid delivered from the pump. The pump is turned on to initiate accumulation of the pressurized fluid in the accumulator when a pressure of the pressurized fluid falls below a lower limit, and turned off when the pressure rises to an upper limit. The detecting device detects an occurrence of leakage of the precharged gas from the accumulator, where a time duration between moments of activation and de-activation of the pump is less than a predetermined reference value.

Abstract: The method and apparatus provides an improved system for monitoring air brakes of a motor vehicle and providing the operator with a signal when brake adjustment or repair is required. A permanent magnet is mounted to a slack adjuster or push rod for air brakes of the vehicle and the magnet is moveable with the rod. A housing containing a magnetically actuated switch, a power supply and an audible single generator is fixedly mounted relative to the push rod. As the magnet on the push rod is moved within a predetermined distance of the fixed housing, the magnetically actuated switch actuates the audible signal generator to produce a warning signal indicating that brake adjustment is required. The system has its own electrical power supply which operates independently from other electrical systems in the vehicle and therefore does not depend upon the electrical power of the vehicle itself for proper operation.

Abstract: A warning for a vehicular air brake system, which system is powered by air compressed by a rotary compressor. A sensor senses rotation of some part of the compressor, and if a signal respective to rotation is not sensed during a predetermined increment of time, an alarm is caused to alert the operator of an impending lack of compressed air.

Abstract: A failure warning device is provided for use with an auxiliary pump unit made ready by either an ignition-on signal or a brake-on signal and activated by a pump-failure signal. The failure warning device has a monitor circuit coupled to a warning circuit. For maintaining reliability of the auxiliary pump unit, the module circuitry is wired as a monitor not including circuit components of the auxiliary pump unit. It has a first input coupled to a common ready signal produced by the pump unit and a second input coupled to a motor terminal of the pump unit. The monitor circuit responds to failure-related states of the ready signal and the motor terminal impedance and voltage by generating an anomaly signal. The alarm circuit switches on an alarm, such as a buzzer and light, when it receives both the ignition-on and anomaly signals.

Abstract: A thermocouple for use with a brake block outputs a signal indicative alternatively of the steady state temperature of the brake block friction element and of the transient temperature of the friction element brake drum interface.