Abstract: In a vehicle anti-skid hydraulic braking system of the pump/re-apply type the pump plunger is of differential outline and works in a stepped bore. An annular chamber and a full pump chamber are defined in the bore on opposite sides of the head of the piston. The annular chamber is pressurized by fluid at a pressure dependent on the difference in pressure between the master cylinder and the brake, and the chamber is subjected to the pressure in the annular chamber in one direction and the pressure in the master cylinder in the opposite direction. The system is therefore provided with a pump which forces fluid back to the master cylinder but with torque levels similar to a pump which acts against brake pressure.

Abstract: A reflective optical wheel speed transducer system is disclosed. The system utilizes a single optical fiber to transmit light to a pair of interrupter discs, and to collect light reflected from the discs. One of the interrupter discs is stationary, and one is rotated at an angular velocity proportional to the rotational speed of a wheel. Both discs are provided with alternating, regularly spaced reflecting and transmissible areas. The reflecting areas of the stationary disc reflect a constant bias level of light to the optical fiber. The reflecting areas of the rotatable disc modulate light passing through the transmissible areas of the stationary disc at a rate proportional to the angular velocity of the wheel. Thus, the interrupter discs generate a modulated light signal that rides on top of the fixed bias signal. Decoding circuitry is provided to convert the modulated component of the light signal to an electrical signal that represents the rotational speed of the wheel.

Abstract: An antiskid control system wherein the conventional method of performing an opening/closing change-over operation by a pulse train signal on a electromagnetic valve for increasing hydraulic braking pressure at a variable rate of increase is not employed but the pressure increasing rate is arranged to be variable by the use of an electromagnetic valve having some throttled position.

Abstract: A braking system having a pressure modulator which, during normal braking operation, delivers a fluid pressure which is a predetermined multiple of a fluid pressure generated by the master cylinder to a wheel cylinder. The pressure modulator has a solenoid actuator which is energized during braking force proportioning and anti-skid operations to reduce the delivery pressure. In a preferred embodiment, the pressure modulator further includes another solenoid actuator for increasing the delivery pressure during braking force proportioning operation and for delivering fluid pressure during traction control operation.

Abstract: A slip-controlled brake system for automotive vehicles contains a braking pressure modulator (5) operated as a function of the deceleration and having an inert mass (10) which rotates with the vehicle wheel and which, upon a deceleration of the wheel, against resetting forces, is axially displaceable on a shaft (9) rotating with the wheel velocity. A wheel deceleration threshold value being exceeded, a valve member (21) will be actuated and thus the braking pressure will be prevented from increasing further or there even will be a reduction of the braking pressure. The deceleration threshold value is not constant but variable dependence on the braking pressure in the wheel brake (4) of the controlled vehicle wheel. Thereby an adaption of control to the road conditions or rather to the momentary friction coefficient is achieved.

Abstract: A slip-controlled hydraulic brake system for all-wheel driven motor vehicles equipped with lockable differentials (2, 3) is provided with sensors (S.sub.1 -S.sub.4, 33-36) for measuring the rotational behavior of the wheels. Electronic circuits (44) are provided for logic combining and processing the sensor signals, and for generating braking pressure control signals by way of which the brake pressure in the individual wheel brakes (16-19) is variable in response to the rotational behavior of the wheels and to a reference variable. To compensate the increased moments of inertia as a result of the moments transmission, by way of the lockable differentials (2, 3) in this brake system the brake pressure in the rear-wheel brakes (18, 19), can be modulated at a lower control frequency as compared with the brake pressure in the front-wheel brakes (16, 17).

Abstract: A failsafing device is proposed for an anti-skid system of a tractor-trailer combination. If the trailer anti-skid system fails at the rear axle, instead of shutting off the entire anti-skid system of the trailer, the anti-skid control at the front axle of the trailer is maintained.

Abstract: An electromagnetically actuatable pressure modulator for anti-locking brake systems utilizes a variable lever-type transmission interposed between a pressure relief piston of the modulator and the compression spring biased armature of an electromagnet whereby the non-linear force/air-gap relationship of the electromagnet is converted to a linear variation of the force applied to the pressure relief piston for moving same. When a predetermined maximum brake pressure is applied to the modulator, the latter automatically isolates the wheel cylinder from the master cylinder.

Abstract: The present invention contemplates a preferred position for mounting an antilock control system that uses a single wheel speed sensor. The wheel speed sensor is mounted to sense speed of rotation of the main differential gear in a differential gear assembly and generates a wheel speed signal indicative of the average rate of rotation of at least two wheels of the vehicle. The sensing point is beyond the final reduction in gear ratios so as to eliminate any need to accommodate different axle ratios. The preferred mounting position also reduces velocity fluctuations caused by oscillations of the truck driveline. A microprocessor controller is mounted in close proximity to the wheel speed sensor so as to minimize the length of sensor leads and, hence, the susceptibility of the antilock controller to electromagnetic interference.

Abstract: A hydraulic brake system with slip control for automotive vehicles comprising a master cylinder (2) pressurizable by a hydraulic power booster (1), in which system valve(s) (31,27,32,28,33,23) are inserted between the master cylinder (2) and the wheel brakes (29,30,24,25) connected to the master cylinder (2) which allow pressure fluid removal from the wheel brakes (29,30,24,25) that can be replenished out of the pressure chamber (19) of the hydraulic power booster (1) by way of a change-over valve (36). A stroke limitation of the brake pedal (8) is effected during slip control. The end surface of the master cylinder piston (5) close to the working chamber (16) being larger than the is effective surface of the booster piston (4), and wherein a stepped piston is employed as master cylinder piston (5) with an annular surface (18) thereof being adapted to be acted upon in the actuating direction by the pressure prevailing in the working chamber (16).

Abstract: The present invention concerns a control valve for use in a vehicle anit-lock braking systm adapted to control the application of pressurized brake fluid to at least one selected vehicle brake. The valve includes an outer housing having an inlet coupled to receive pressurized brake fluid from the vehicle master cylinder and an outlet coupled to supply pressurized brake fluid to the selected vehicle brakes. A passageway is formed in the housing for connecting the inlet to the outlet. A normally open isolation valve is located in the passageway and is utilized to control the flow of fluid through the passageway between the inlet and the outlet. When an incipient wheel lock condition is detected, the isolation valve can be closed to prevent a further increase in pressure to the controlled brakes and to hold the pressure supplied to the controlled brakes at a relatively constant level.

Abstract: A brake device for vehicles comprises a master cylinder, a wheel brake adapted to be operated by the output hydraulic pressure from the master cylinder to apply a braking force to a wheel, and an antilock control unit, having therein an inertia type wheel angular deceleration sensor driven by the wheel through a transmission device and adapted for controlling the output hydraulic pressure from the master cylinder in accordance with the output of the sensor, the antilock control unit being carried on the support system for the wheel. Defined on one side of the wheel is a recess which is concave toward the other side of the wheel from the central rotational plane of the rim of the wheel, and the antilock control unit and transmission device are disposed in the recess.

Abstract: Axle assemblies having a sensor of the mechanical input shaft type are difficult to access and subjected to radial and axial loads which cause premature failure. A connecting arrangement affixes a sensor body to a support bracket adjacent a second end of a rotatable spindle and maintains an input shaft of the sensor within a preselected range of axially aligned positions with respect to a spindle axis. A coupling arrangement couples the second end portion of the spindle to the input shaft and transfers only rotational motion from the spindle to the input shaft. The coupling arrangement permits a preselected amount of freedom of movement of the spindle relative to the sensor in axial and radial directions. Thus, damage to and premature failure of the sensor is alleviated and accessability is substantially improved. The axle assembly is particularly suited for use on an automatic guided vehicle.

Abstract: Sensors of the type capable of delivering a signal representative of the rotated position of an output member frequently fail prematurely because of excessive side and axial loading and electrical conductor damage. A mounting arrangement for a first sensor has an apparatus for connecting an input shaft of the first sensor to an output member, and apparatus for connecting a body of the first sensor to a housing and maintaining the body against rotation about an input shaft axis and thereby reducing the force applied to the sensor body caused by wobble of the first sensor. The mounting arrangement has a connecting shaft and guide assembly, which guides and protects an electrical conductor both internally and externally of the housing, and the first apparatus permits the passing of the electrical conductor thereby. Therefore, premature failure of and damage to the electrical conductor and the first sensor is substantially reduced.

Abstract: A vehicle brake system including a brake force booster, controllable a brake pedal, for actuating a main brake cylinder in order to supply wheel brake cylinders with braking pressure for service braking operations and also includes brake pressure control valves, which direct braking pressures into individual wheel brake cylinders if there is a danger that the wheels will lock during braking. To this end, pressure is supplied to the brake pressure control valves from the brake force booster via controlled valves. In order to be able to reduce drive slip as well, the controlled valves are embodied as a switchover valve, so that pressure can be directed to the brake pressure control valves directly from a pressure supply container bypassing the brake force booster. The vehicle brake system is inexpensively further embodied for reducing drive slip by modifying the control valves.

Abstract: The hydraulic brake system with slip control comprises a master cylinder piston for operating a wheel brake, in which hydraulic medium tapped from the wheel brake during slip control will be supplied to the wheel brake from an auxiliary pressure source via a master cylinder gasket acting as check valve. The operating stroke of the master cylinder piston is limited by pressurization of a positioning piston through which a master cylinder piston rod is passed in a sealed manner and which is guided axially displaceable in a sealed manner in a housing. In order to prevent an abrupt movement of the positioning piston upon pressurization the positioning piston is constructed as a stepped piston whose smaller diameter is sealed with respect to the housing and having a piston step which in combination with the seal between the smaller diameter portion of the positioning piston and the housing annular chamber with a volume which is dependent on the pedal travel.

Abstract: A damping system having a fluid-operated friction device located at the hinge connection of an articulated vehicle that provides progressively increased damping to movements about the yaw axis after the speed of the vehicle increases beyond a predetermined speed.

Abstract: A hydraulic pump with an unloading function which comprises a pump body, a spring chamber formed in the pump body and communicating with a fluid reservoir, a pump chamber formed in the pump body and communicating with the spring chamber and an accumulator through a suction valve and a delivery valve, respectively. An operation chamber is also formed in the pump body and accommodates a drive member such as a pump drive shaft. A plunger slidably extending through a first partition between the spring chamber and the pump chamber, and a tappet having a smaller diameter than that of the plunger and slidably extends through a second partition between the pump chamber and the operation chamber to abut against the plunger. A spring is accommodated in the spring chamber and is adapted to apply a predetermined resilient force to the plunger to bias it toward the tappet.

Abstract: A motor vehicle adapted to be used on tracks, especially for the public local passenger traffic, with a steerable vehicle axle and with at least one non-steerable vehicle axle and with track-determining cross-guide rollers arranged on both sides of the vehicle which are provided at least within the area of the steerable wheels and are supported near the end points of mounting arms that are relatively fixed; a force-measuring device for determining the cross-guide force is provided in the mounting or bearing support of at least one of the cross-guide rollers of each vehicle wheel while a brake pressure medium valve is adapted to be influenced by the force-measuring device in such a manner that a brake deceleration is automatically initiated when the vehicle exceeds a threshold value of the cross-guide force.

Abstract: A vehicle braking system including a wheel hub, a hub member separate from the wheel hub, a torsional coupling device and a magnetically actuable brake spring. In a preferred embodiment, the hub member is connected to the vehicle suspension by the torsional coupling device and, upon actuating, the brake spring wraps around the wheel hub to cause the hub member and the wheel hub to be nonrotatably joined together. In another embodiment, the wheel hub is torsionally connected to the hub member and actuation of the brake spring causes the hub member to be nonrotatably joined to the vehicle suspension. The movements of the wheel hub relative to the vehicle suspension permitted by the torsional coupling are monitored by an electronic control circuit that guards against wheel lockup or skid conditions. The electronic control circuit intermittently triggers the brake spring between brake release and approaching wheel lockup so as to incorporate anti-skid performance with the brake function.

Abstract: A sensor for responding to the rate of change of changing rotational speeds of a rotating vehicle wheel and including a flyweight coupleable for rotation in response to wheel rotation and decoupleable in response to a rate of change of a changing rotational speed of the wheel which exceeds a certain threshold rate. In accordance with the present invention, a brake device is operatively connected with the flyweight for constantly exerting on the flyweight a torque resisting rotation of the flyweight. Provision is made for signalling of any occurrence of an excessive rate of change of rotational speed of the wheel continuously for the interval of time during which a threshold rate is exceeded, and the brake device may be operable in response to such signalling for changing the level of torque exerted.

Abstract: In the combination of a rotating member such as an automotive vehicle wheel, a brake operative for slowing the rotating member or wheel, and a sensor for signalling any occurrence of an excessive rate of retardation of the rotating member or wheel, an improvement which facilitates optimum response of the sensor by varying the sensitivity or responsiveness of the sensor upon variations in a vehicle operating condition such as the weight imposed on the rotating member or wheel or the braking pressure. In specific forms disclosed, variation in sensitivity of the sensor is accomplished by a variable ratio transmission means mechanically interposed between the sensor and the rotating member or wheel and which is responsive to vehicle operating conditions.

Abstract: A sensor for responding to the rate of change of changing rotational speeds of a rotating vehicle wheel and including a flyweight coupleable for rotation in response to wheel rotation and selectively decoupleable in response to the exertion on the flywheel of a torque having a magnitude greater than a threshold magnitude due to a change in rotational speed of the wheel. In accordance with the present invention, a control device is operatively connected with the flyweight for exerting on the flyweight torques resisting decoupled rotation of the flyweight and is operable for changing the level of torque from a first level to a second level. Provision is made for signalling of any occurrence of an excessive rate of change of rotational speed of the wheel, and the control mechanism is operable in response to such signalling for changing the level of torque and thereby for causing the sensor to signal continuously for the interval of time during which the threshold rate is exceeded.

Abstract: A sensor for responding to the rate of change of changing rotational speed of a rotating member such as a vehicle wheel and including a flyweight coupleable for rotation in response to wheel rotation and selectively decoupleable in response to the exertion on the flyweight of an inertia torque having a magnitude greater than a threshold magnitude due to a change in rotational speed of the member. In accordance with the present invention, control means for exerting on the flyweight torques resisting decoupled rotation of the flyweight takes the form of a restraining mechanism, while signalling of any occurrence of an excessive rate of change of rotational speed of the member is accomplished through a magnetically actuable electrical switch.

Abstract: This invention relates to a vehicle axle assembly comprising an axle, means for rotatably mounting a ground engaging wheel at each end of the axle, a fluid power brake mechanism mounted to the axle adjacent each end thereof, each brake mechanism being operative when actuated to restrain rotation of a wheel rotatably mounted at that end of the axle, a valve having a body, means providing a source of pressurized fluid to the body, conduits connecting the body to the brake mechanism at each end of the axle, relay means within the body being operable when actuated to modulate fluid pressure from the source to the brake mechanism, a wheel speed sensor mounted at each end of the axle, an annular sintered metal rotor press fitted on a hub rotatably mounted on each end of the axle and supporting the wheel, the rotor having a plurality of circumferentially and equally spaced notches, the notches so disposed on the rotor to angularly sweep by the sensor, the sensor adapted to generate electrical signals indicative of t

Abstract: A mechanical antiskid regulator has a flywheel mass which is journalled for rotary movement independent of the axle and wheel and is provided with a cam received in a recess of a cam disc coupled to rotate with the wheel on the axle. Two locking elements are pivotally connected to a ring segment and are suspended from the cam disc so as to be positioned on either side of the central position of the cam. A rotatably mounted stop is engageable from either direction of rotation with the ring segment to displace the ring segment so as to move a portion of a locking element into the path of the cam to prevent the flywheel mass from deflecting in that direction.

Abstract: A wheel speed sensor for a wheel mounted on the end of an axle shaft of a drive axle can be utilized in an anti-wheel lock brake control system. The sensor includes an electromagnetic sensing device which is mounted on the drive axle housing in alignment with the axle shaft inwardly of the wheel. An excitor rotor of the sensor is preferably mounted on the differential casing about the axle shaft in alignment with the sensing device for rotation while maintaining the distance between the sensing device and the rotor within a predetermined limit without allowing contact therebetween. A C-shaped spring partially encircles the rotor as a pair of tabs at its ends extend inwardly through the rotor to make contact with a corresponding pair of grooves in the axle shaft. The C-shaped spring member drives the rotor in response to rotary movement of the axle shaft but allows removal of the axle shaft for maintenance while the rotor is retained within the protective interior of the housing.

Abstract: A non-elastomeric sensor holding fixture using metal-to-sensor contact friction in a wheel slip control system maintains a wheel speed sensor in intimate contact with an exciter wheel without the excessive sensor wear which otherwise happens when the wheel speed sensor is held in place with resilient elastomeric holder. The use of metal-to-sensor frictional contact in the holding fixture avoids the hardening and seizing normally occurring in elastomeric-to-sensor frictional contact due to time and allows readjustment of sensor position after extended use.

Abstract: In a bearing assembly having at least two relatively rotatable members, a device having means for generating a magnetic field and means for sensing variation in the magnetic field, said bearing assembly including means for inducing variations in the magnetic flux which variations have a frequency proportional to the rotational speed of one member relative to other member, said inducing means being associated with one of said members and said means for sensing variations being associated with said other bearing member and seal means partly defined by said members completely sealing said inducing and sensing means.

Abstract: An improved inertia switch having a variable threshold and operating time comprises a flywheel, a driving member, electrical contact elements carried respectively by the driving member and the flywheel and return means coupled between the driving member and the flywheel. The contact element carried by the flywheel comprises on the one hand a contact terminal integral with a support coupled by friction to the flywheel, the contact terminal co-operating with a part of the contact carried by the driving member, and on the other hand, a contact surface integral with the flywheel co-operating with a second contact part carried by the driving member. The switch is particularly applicable for detecting imminent locking of a vehicle wheel.

Abstract: A disc adapter for attaching rotatable discs of a disc brake system to a wheel is modified to include an exciter ring of a sensor unit of an anti-skid system used in conjunction with the braking system. The exciter ring is oriented co-axially with the wheel and contains a plurality of equally and annularly spaced ripples. Rotational movement of the exciter ring and the wheel is detected by a stationary magnetic pickup device adjacent to the exciter ring.

Abstract: A bracket for mounting a wheel speed sensor module to a vehicle axle. The bracket is a stamped metal part including a central portion which is secured to the axle and end portions for mounting the sensor module. A tab formed integrally with the central portion of the bracket locates the bracket on the axle.

Abstract: A rotation indication system having an improved sensing device for determining the velocity of a rotating body is provided. The improved sensing device is tubular in configuration and includes a source of magnetic flux and two pole pieces that define a split magnetic field. The sensing device is mounted in close proximity to a rotor which is connected to the rotating body. The rotor has apertures which interrupt the split magnetic field producing an output signal with a frequency proportional to the velocity of the rotating body. The sensing device is oriented relative to the rotor apertures so that each pole piece is alternatively in register with an aperture to produce the desired output signal. Since the sensing device is tubular in shape, it can be rotated about its axis to obtain the desired orientation with the rotor apertures, thus permitting the use of the sensing device with a wide range of rotor diameters having various aperture spacings.

Abstract: A wheel speed sensor is adapted to be mounted entirely within the bored end of an axle. The sensor comprises a rotor, stator, permanent magnet and coil, all compactly mounted in a hermetically sealed housing. A retainer is provided within the axle bore for securing the sensor against rotational and axial movement relative to the bore. The rotor shaft which is mounted within the housing is provided with an extension which passes in sealed relationship through the housing and beyond the end of the axle. A connector arm is attached to the rotor shaft extension for engagement with the wheel hub cap.

Abstract: A vehicle wheel speed sensor includes a rotor and a stator. The rotor is annularly provided to rotate adjacent and relative to an axle. The stator is mounted on the axle. A point sensor is included in the stator for providing pole pieces 180.degree. diametrically opposed and directed radially outwardly toward and in radial alignment with the annular rotor for proximate electrical association therewith.

Abstract: A speed control device for a small-sized vehicle includes a centrifugal governor for generating a thrust corresponding to a centrifugal force generated by a wheel of the vehicle and a link mechanism for operatively connecting the centrifugal governor to a throttle valve and braking mechanism of the vehicle so that the throttle valve and braking mechanism may be operated in a correlationship by the thrust of the governor.

Abstract: Apparatus on each vehicle in a train, for effecting a release of an emergency brake application upon a complete stop of the train, comprises a fluid pressure operated brake pipe vent valve device that is supplied with fluid under pressure from a quick action chamber when the emergency brake application is effected, a release valve device operable upon the release of fluid under pressure therefrom to vent fluid under pressure from the brake pipe vent valve device to atmosphere to cause closing of the brake pipe vent valve thereby enabling recharging of the brake pipe to effect a release of the prior emergency brake application, and a speed responsive device for supplying fluid to the release valve device at a pressure proportional to the speed of the train.

Abstract: A booster operated master cylinder piston for use in an anti-skid braking system includes a modulator piston located between the master cylinder piston and the booster valve assembly. In the event of a skid the pressure of booster fluid acting on the modulator piston is relieved.

Abstract: An electrodynamic tachometer has a rotor connected to the end of an axle and a stator. An annular element having substantially a C-shaped cross section connects the outer surface of the stator to a bearing housing enclosing the end of the axle. The annular member is of a flexible rubber material so as to be relatively stiff with respect to torsion but flexible with respect to axial and radial deflections.

Abstract: In the system disclosed a detector detects whether a vehicle's engine is started or not. In response to starting of the engine, the detector causes an actuating circuit to actuate an automatically regulated skid-control modulator that controls the hydraulic pressure between a master cylinder and a wheel cylinder. A second detector senses whether the modulator is operating. A detecting circuit determines whether the operation of the skid control system is normal or abnormal in response to the output signal from the second detector and the actuating circuit. A memory circuit stores the output signal from the detecting circuit to generate a warning signal. An alarm device responds to the warning signal to produce an audible or visible alarm.

Abstract: A speed sensing device for a wheeled vehicle in which the sensing device is mounted within a cavity formed at the outer end of an axle shaft. A flexible and splined drive connection transfers the drive from the wheel of the vehicle to the rotor of the speed sensing device. In this way, axial, angular and radial variations in spacing between the wheel and axle will not affect the signal generated by the speed sensing device nor will such variations subject the speed sensing device to undue loads.

Abstract: An inertia switch for detecting impending locking of a rotaty member, such as a vehicle wheel, and having a variable deceleration detection threshold has a flywheel rotatable on a shaft adapted to be driven by the rotary member, a flywheel drive element on the shaft and biased by a spring into engagement with a stop on the flywheel, the flywheel and drive element carrying respective contacts of a pair of closable contacts which are open when the drive element is engaged with the stop, and a weighted lever pivoted on the flywheel eccentrically of the shaft, and co-operable with the drive element to apply a force dependent upon the rotational speed of the flywheel to oppose closing of the contacts. A rigid link on the spring may connect a free end of the lever with the drive element, and the lever may be a bell crank having one weighted limb and a second limb which abuts against the drive element and to which the spring can be attached.

Abstract: A wheel speed sensor for a wheel mounted on the end of an axle shaft of a drive axle can be utilized in an anti-wheel lock brake control system. The sensor includes an electromagnetic sensing device which is mounted on the drive axle housing in alignment with the axle shaft inwardly of the wheel. An excitor rotor of the sensor is preferably mounted on the differential casing about the axle shaft in alignment with the sensing device for rotation while maintaining the distance between the sensing device and the rotor within a predetermined limit without allowing contact therebetween. A C-shaped spring partially encircles the rotor as a pair of tabs at its ends extend inwardly through the rotor to make contact with a corresponding pair of grooves in the axle shaft. The C-shaped spring member drives the rotor in response to rotary movement of the axle shaft but allows removal of the axle shaft for maintenance while the rotor is retained within the protective interior of the housing.

Abstract: An autochecking arrangement for a hydraulic system, which includes an actuating piston displaceable under the action of a pressure source and controllable as to displacement independently of the pressure of the pressure source by a valve arrangement, comprises a pressure sensor connected into the hydraulic system and emitting signals corresponding to at least two sensed pressure thresholds, a switching system for providing sequentially different actuation states of the hydraulic system and a monitor for monitoring the correct actuation of the hydraulic system in cooperation with the signals from the pressure sensor.

Abstract: A rotation indication system having an improved sensing device for determining the velocity of a rotating body is disclosed. The improved sensing device is tubular in configuration and includes a source of magnetic flux and two pole pieces that define a split magnetic field. The sensing device is mounted in close proximity to a rotor which is connected to the rotating body. The rotor has apertures which interrupt the split magnetic field producing an output signal with a frequency proportional to the velocity of the rotating body. The sensing device is oriented relative to the rotor apertures so that each pole piece is alternatively in register with an aperture to produce the desired output signal. Since the sensing device is tubular in shape, it can be rotated about its axis to obtain the desired orientation with the rotor apertures, thus permitting the use of the sensing device with a wide range of rotor diameters having various aperture spacings.

Abstract: An improved wheel speed sensor assembly for installation in association with a wheel rotatably mounted on a hollow axle which has an open-ended spindle is of a type which includes an excitor ring mounted within a hub cap of the wheel and a magnetic sensor device capable of electrically transmitting a speed signal through electrical wiring extending through the interior of the axle. The improvement includes the sensor device being disposed within a sensor housing which is, in turn, disposed within the hub cap and mounted thereon for relative rotation about a central axis of hub cap with the sensor device in alignment with the excitor ring. The sensor housing has a connector portion generally extending toward and aligned with the open-ended spindle and electrically coupled to the wiring when the hub cap is secured on the wheel.

Abstract: A power train having an engine, a retarder and a transmission and controls to manually control the retarder and an engine overspeed responsive control operative to shorten a link in the manual control to move the retarder control valve to automatically apply the retarder in response to engine overspeed. An air cylinder in a link of the retarder apply linkage is actuated by vehicle air brake pressure controlled by a transmission input or engine speed governor to apply the retarder and prevent engine speed above a predetermined value and thus limit vehicle speed. When the retarder apply air cylinder shortens the link, the retarder apply pedal engages the brake off stop to provide the reaction to move the retarder valve.

Abstract: A rotation indication system having an improved sensing device for determining the velocity of a rotating body is disclosed. The improved sensing device is tubular in configuration and includes a source of magnetic flux and two pole pieces that define a split magnetic field. The sensing device is mounted in close proximity to a rotor which is connected to the rotating body. The rotor has apertures which interrupt the split magnetic field producing an output signal with a frequency proportional to the velocity of the rotating body. The sensing device is oriented relative to the rotor apertures so that each pole piece is alternatively in register with an aperture to produce the desired output signal. Since the sensing device is tubular in shape, it can be rotated about its axis to obtain the desired orientation with the rotor apertures, thus permitting the use of the sensing device with a wide range of rotor diameters having various aperture spacings.