Abstract: A brake shoe arrangement for disc brakes for motor vehicles, and a method for the production thereof, comprising a brake shoe (2) including an anchor plate (4) having a friction pad (6), secured thereto and comprising a wire brake shoe spring (18) formed as a stem spring and including at least two winding sections (20,22) from which emerges one free spring stem, with the brake shoe spring (18) being inserted into at least one recess (12,14) of the anchor plate such that one winding section is located on one side of a bridge-type projection (16) provided in the recess. The projection extends substantially in parallel to the anchor plate. In order to provide a safe support for pad-wear warning contact (10), the bridge-comprising (16) forms a substantially closed ring comprising a continuous aperture (34).

Abstract: A brake rod extension indicator in which sensor means is incorporated into the brake actuator to indicate when the brake rod overextends. This can give warning of the need for brake adjustment, need for replacement of linings, or of failure of parts in the brake system.

Abstract: A hydraulic disk brake apparatus especially useful for braking the rotation of a hoisting drum used to support a drill string in a well. The apparatus comprises a hydraulic fluid pump having an actuating lever, a pair of brake calipers having hydraulically actuated friction pads for engaging a brake disk coupled to the drum for rotation therewith, hydraulic fluid lines interconnecting the pump and the friction pads, and a mechanism for converting the braking reaction force caused by the torque applied to the calipers, when the pads engage the rotating disk, to an additional hydraulic force proportional to the amount of torque so applied to the calipers and applying this additional hydraulic force to the pads. This renders the braking action self-energized and provides a physical indication, i.e., a "feel", in the brake actuating lever reflecting the braking action actually take place on the drum.

Abstract: A brake lining wear sensor includes a metal contact secured to a grounded brake lining support plate through a semiconductor ceramic bushing containing silicon carbide and silicon nitride which establishes an electrical resistance between the contact and the support plate so that the contact has a resistance to ground when the brake lining is not worn, but when the brake lining is worn and the contact touches a grounded brake rotor or drum, a short to ground occurs. The sensor is coupled by a lead wire to an indicator circuit which tests for the resistance value in the circuit path to ground to determine whether the contact is connected to the indicator circuit and whether it is electrically grounded to the rotor. An indicator lamp comprises a tri-color LED to emit different colors signifying a normal condition, an open circuit or a worn brake lining condition.

Abstract: A brake lining wear sensor includes a metal contact secured to a grounded brake lining support plate through a semiconductive ceramic bushing containing silicon carbide and silicon nitride which establishes an electrical resistance between the contact and the support plate so that the contact has a resistance to ground when the brake lining is not worn, but when the brake lining is worn and the contact touches a grounded brake rotor or drum, a short to ground occurs. The sensor is coupled by a lead wire to an indicator circuit which senses the resistance value in the circuit path to ground to determine whether the contact is connected to the indicator circuit and whether it is electrically grounded to the rotor. An indicator lamp comprises a tri-color LED to emit different colors signifying a normal condition, an open circuit, or a worn brake lining condition.

Abstract: A railroad car brake system operable by an air bag which includes double acting brakes operable on the wheels. Links suspend the brakes and the live and dead levers connected by an adjustable connecting link mechanism are operable by the air bag. Slack as a result of wear in the brakes is automatically taken up.

Abstract: A shock absorber comprising an elongated tubular element, closed at one end, into which element at the other end a piston can move as counter element, is disclosed. The space delimited by the counter element inside the tubular element is divided intoa high pressure chamber closed at one end closed by a first movable separating element which can come to rest against a stop element,a fluid chamber divided into at least two sections at the other end, which sections are separated from each other by a restricting element, which fluid chamber is closed by a second movable separating element embodied as a piston, anda low pressure gas chamber positioned between the first and second movable separating elements.

Abstract: This brake adjustment monitoring device, serves to warn the operators of trucks, buses and other vehicles, when their brakes are in need of adjustment or repair, which will effectively cut down the number of accidents caused by brakes being out of adjustment. Primarily, the device consists of a magnet adjustably secured to the shaft of the diaphragm within each air chamber. It also includes a block with a reed switch in it that is in cooperation with the magnet, so as to close the switch by magnetic force when the shaft of the air chamber moved outward too far, when the operator touches the brake pedal of the vehicle. It further includes a cab mounted indicator unit, having a buzzer and a bulb for alerting the operator when the brakes are in need of adjustment.

Abstract: A test system for an electromagnetic brake system for a trailer, which includes a battery disposed in the towing vehicle for powering a plurality of brake electromagnets disposed in the trailer, an automatic controller for regulating current flow, resistors for both proportioning and balancing current flow among the plurality of brake electromagnets and between the towing vehicle and the trailer, respectively, the proportioning resistor is dropped from the system by a solenoid when the towing vehicle is put into reverse for testing, a gauge having both green and red zones is inserted into the system by a relay switch when the towing vehicle is put into reverse for testing, and a pushbutton for actuating the gauge is provided.

Abstract: In a brake assembly (10) having an infrared fiber optic element (54) for transmitting an operational signal to a sensor (66) through which an indicator (68) is provided with a substantially instantaneous indication of the temperature of the brake stack (26).

Abstract: A device for determining or checking the condition, state, or other parameters of a pressure fluid contained in a hydraulic system substantially comprises a body which may be screwed into the wall of a chamber or of a line of the hydraulic system, which at its front face having contact with the pressure fluid has a measuring or testing device, and which at its part accessible from the outside has an electric contact which is in communication with the measuring and testing device via a line passed through a central bore.

Abstract: A wear indicator for an automative driveline clutch comprises a base 20 fixed to the clutch housing 10, and a microswitch 16 mounted on a carrier 30. The carrier 30 is set in position by the first full disengagement movement of the clutch lever 12. The length of the aperture 32 is such that the lever 12 engages the microswitch 16 when the clutch linings are worn.

Abstract: A brake shoe assembly is composed of a carrier plate, a friction material lining secured to the carrier plate and the brake-shoe spring. The brake-shoe spring comprises between its legs a loop-shaped portion which is supported in a recess in the brake shoe, this recess being open towards the edge of the brake shoe. Arranged at the open recess is a projection which extends into the loop-shaped portion between two convolutions of the brake-shoe spring. The two convolutions are interconnected by a wire portion disposed at the area of the legs.

Abstract: A sliding key (10), interposed between the end (5) of an arm (4) of the fixed support (1) and the adjacent profiled end (60, 70) of the sliding caliper (8), is immobilized axially by a component (15), advantageously elastic, having end portions (16) cooperating in engagement with the axially opposed ends of the key (10) and joined by an intermediate portion (20) of undulating profile defining with the adjacent outside zone of the end (5) of the arm (4) a channel (24) for a wire conductor (25) to pass through, for connection to a pad wear detector, brought to the side of the brake opposite this pad.

Abstract: An electromechanical pipe snubbing system and an electromechanical pipe snubber. In the system, each pipe snubber, in a set of pipe snubbers, has an electromechanical mechanism to lock and unlock the snubber. A sensor, such as a seismometer, measures a quantity related to making a snubber locking or unlocking decision. A control device makes an electrical connection between a power supply and each snubber's electromechanical mechanism to simultaneously lock each snubber when the sensor measurement indicates a snubber locking condition. The control device breaks the connection to simultaneously unlock each snubber when the sensor measurement indicates a snubber unlocking condition. In the snubber, one end of the shaft slides within a bore in one end of a housing. The other end of the shaft is rotatably attached to a pipe; the other end of the housing is rotatively attached to a wall.

Abstract: A first wear feeler arranged in a brake lining slides within a borehole under the pressure of a spring in the direction towards a crown or disk. The feeler is immobilized at the level corresponding to the maximum wear of the lining. A second borehole which extends from the maximum wear level to the friction surface of the lining contains a second, licking feeler connected electrically to the first feeler. A line to an alarm is provided with a switch which is open upon braking maneuvers and closed otherwise. The closing of the alarm circuit other than during braking maneuvers is produced either in the case of licking of the lining on the disk or on the crown by the second feeler or in the case of maximum wear by the first feeler.

Abstract: An inductive displacement transducer is described in which the magnitude of the phase difference between A.C. current and voltage in a coil is dependent upon the axial displacement of a monitored object. The phase difference depends upon the axial position relative to the coil of a short-circuit turn which moves with the monitored object. A magnetic flux concentrator, which may be combined with the short circuit turn, enhances the flux linkage between the short-circuit turn and the coil. In order to sense the height of a vehicle suspension strut, the coil is mounted on a plastics dirt shield, the short-circuit turn is provided by a sleeve plated with an electrically conductive metal and secured to the strut cylinder. Various circuits are described for monitoring the height signals produced by the different suspension struts of a vehicle.

Abstract: A system for braking axle-attached wheels of a tractor trailer and the like includes first and second arrays of discs symmetrically opposed about the centerline of a tubular axle containing the arrays of discs; symmetrical also in each array of discs is a first plurality of discs slidably attached to the axle and a second plurality of discs slidably attached to the housing; the axle comprises a stub axle at each end protruding from the housing in position for mounting a wheel or wheels; in braking, a two-lobe, cam-actuated system simultaneously compresses the respective arrays of discs in directions opposite each other for frictional retardation of the axle; bearings carry the axles; the cam actuated system includes a spreader plate driving a pressure plate on each side of centerline.

Abstract: A wear-limit warning device for a vehicle disc brake, warning the vehicle driver that a maximum permissible wear limit is reached on the friction pad or pads. The warning device comprises a projection protruding sideways from the end face of a backing plate of each friction pad, and a warning member made from a spring sheet material. The warning member consists of a mounting leg portion, a contact portion and a spring portion connecting the leg and contact portions. The leg portion having a pair of legs which grip therebetween an end portion of the backing plate and the protruding projection thereby attaching the warning member to the backing plate and preventing the same from being shifted out of position during service. The contact portion extends along the end face of the projection until its end reaches a permissible wear limit level of the friction member of the friction pad, and is pressed against the end face of the projection with a resilient force of the spring portion.

Abstract: A disk brake comprises a caliper housing adapted to fit over the edge of a brake disk rotatable about an axis, a pair of brakeshoes in the housing axially flanking the disk and each having a brake pad turned toward the respective face of the disk and a backing plate turned away therefrom, and an actuator in the housing and engaging the backing plates for urging the brakeshoes together against the disk. The backing plates are formed with respective axially throughgoing brakeshoe passages and the housing is formed with respective housing passages in line with the brakeshoe passages. The brake further has a spring compressed axially between the brakeshoes and having respective legs extending toward the shoes, respective pusher portions extending from the legs and lying flatly against the backing plates, and respective guide portions extending from the pusher portions and extending axially through the respective brakeshoe passage and housing passage.

Abstract: A clutch disk of a motor vehicle clutch is provided with a contact element. This contact element is part of a sensing circuit rotating with the clutch disk. This sensing circuit is open as long as the friction pads on the clutch disk are relatively new. Only when the friction pads have been worn to a predetermined degree, the contact element comes into contact with a friction face of the fly wheel disk of the pressure plate of the clutch, so that the sensing circuit is closed. The sensing circuit is connected through a pair of induction coils to a stationary electronic circuitry. This circuitry is influenced by the opening and closing of the sensing circuit and controls indicating means for indicating the degree of wear of the friction pads.

Abstract: A device for warning the allowable wear-limit of a pad assembly in a disc brake. The device comprises (a) a vibration member composed of (i) a fixing portion secured to a lateral end portion of a backing plate of the pad assembly, (ii) a spring portion bent into a curve as an extension from the fixing portion for being located on the rear side of the pad assembly, and (iii) a vibrating portion extended from the spring portion, passing through between the lateral end portion of the backing plate and a torque member movably supporting the same, toward the friction surface of the disc rotor as far as almost reach at a tip thereof a wear limit of the pad assembly, (b) a supporting member supporting the vibrating portion at a root portion thereof against biasing force of the spring portion, and (c) a projection disposed on either the supporting member and the vibration portion for determining contact position therebetween.

Abstract: A brake pad comprises a layer of friction material the working face of which engages a braking surface, and an electrical lead terminating in a contact positioned to engage the braking surface when the friction material is wearing thin, the electrical lead being composed of a flexible strip of insulating material carrying a flexible strip of conductive material, e.g. flexible printed circuit material.

Abstract: A device for measuring wear of linings of a clutch, especially a motor vehicle clutch, with the clutch including a clutch-actuating device which has a push rod displaceable as a function of a position of, for example, a clutch pedal. A push rod includes a larger diameter portion which can be measured in a vicinity of a measurement point by means of a gauge, whereby the push rod acts upon a throwout fork which is adapted to be displaced as lining wear increases from a basic position in a direction of the push rod and indicate a need for replacement as a result of a predetermined change in diameter indicated by the group. The increased diameter portion of the push rod is formed by a frustoconical sleeve displaceable on the push rod. The sleeve is displaceable by a stop provided on a portion of a housing of the clutch when the clutch is thrown out for the first time into a fixed position corresponding to a maximum lining thickness.

Abstract: A clutch or brake control system and method generates an electrical signal upon maximum torque transmission between the relatively displaceable parts of the friction device. This signal can be used as a reference point, changing with each application of the clutch or brake and with wear of the friction members thereof, which is utilized to trigger a controlled clutch or brake application process and may also be used to signal the end of a rapid-closure operation. Electronic circuitry is provided to store and process this signal.

Abstract: A friction lining wear indicator for shoe-drum brakes comprising a sensor mounted on a brake shoe, which actuates an indicator when the thickness of a friction lining carried by a platform of the shoe for engagement with a drum is less than a predetermined value. In order to locate the sensor at the most effective position without machining the lining or fastening the sensor permanently to the shoe, the sensor is located by a mounting device located in a depression in an edge of the platform, and co-operates with the shoe to retain the sensor adjacent the lining. The mounting device comprises a plastics plug, or a resilient clip, and the retaining device is releasable. The sensor comprises a wire loop or a pressed insulation-coated metal strip, and may be integral with the mounting device. The sensor and the drum are connected in a circuit with the indicator which is actuated when the sensor touches the drum.

Abstract: The support for the outboard disc brake lining is a section of the caliper, and no shoe is used. The lining has a boss which fits into a recess formed in the caliper housing. The boss has sufficient shear area to transmit brake torque to the caliper. Center holes in the lining provide a location for a clip to be installed through the outboard caliper section. The clip keeps the lining away from the disc in the rest position and may also function as a lining wear sensor. The results include lighter weight and more usable lining.

Abstract: In an apparatus for preventing runaway of carriers in a power-and-free conveyor, each of the carriers has a runaway preventing stopper rotatable about its center portion in a substantially vertical plane parallel with the direction of advance of the conveyor, and a restraining member engageable with one end of the stopper for usually preventing the other end thereof from turning forward. The stopper is biased always by weighted arm to turn the other end forward. Runaway preventing contact members are arranged at a spacing in each of rising and falling gradient sections of the conveyor along the path of movement of the stopper other end. When the carrier runs out of control in the falling gradient section, the stopper other end collides with one of the contact members and is thereby turned rearward into engagement with the restraining member against the weighted arm while bringing the one end of the stopper into engagement with another contact member to prevent the carrier from running away.

Abstract: An easily insertable and removable brake pad abrasion detector is provided by forming a recess in the rear surface of the pad, a hole in the pad backing plate communicating with the recess, a sleeve in the hole having inwardly projecting one-way pawls and a probe having a circumferential shoulder engaged by the pawls when inserted. The small diameter part of the probe may have an elliptical cross-section so that the pawls may be disengaged by merely turning the probe.

Abstract: An indicator for indicating a predetermined amount of wear of a brake lining comprises a brake lining support member operably connected to a brake actuator and supported thereby, a brake lining is fixedly attached to the brake lining support member and when actuated by the brake actuator frictionally engages a rotating member rotatably mounted on an axle which carries the brake actuator, an electrical contact is connected to an electrical circuit and is disposed on the brake lining support member and insulated therefrom by insulator, the electrical contact has a head portion which contacts the rotating member and the brake lining support member frictionally engages the rotating member and the brake lining is worn to a predetermined level to complete the electrical circuit to energize an indicator connected to the electrical circuit.

Abstract: A portable power chain saw with a safety device to protect against kick-back or recoil movements of the saw. The power chain saw has a handle, a finger guard which is arranged between the handle and the saw chain and acts as an inertial mass, as well as a blocking device which actuates the safety device at the beginning of a kick-back movement. The chain saw also includes a monitoring device, which responds to an operating condition of the chain saw impairing the safety of use thereof by an operator, and which is in effective connection with an indicating device. An auxiliary device may additionally be provided for actuating the safety device, and this auxiliary device is releasable by the monitoring device and ultimately brings the saw to a standstill.

Abstract: A probe mount assembly for a brake wear warning system comprising a probe electrically connected with a warning signal electric circuit and supported by and electrically insulated from one of friction plates by a nonrotatable bushing and a spacer disposed on the opposite sides of said one friction plate.

Abstract: A disc brake including a friction pad disposed on one surface of a rotatable disc and a stationary member displaceably supporting thereon the friction pad. A resilient member is provided between the stationary member and the friction pad for biassing the friction pad in the direction separating from the disc when the friction pad has been urged against the disc in applying the brake.

Abstract: A lining wear indicator for a disc brake of the type including a transversely disposed bridge bar carried on the outboard end of a push rod assembly and bearing against the inboard face of the inboard brake pad. The lining wear indicator comprises a pair of pins secured at their outboard ends to the respective radially outer ends of the bridge bar and extending axially inboard through aligned bores in the inboard web of the caliper to provide, as a function of the length of pin exposed inboard of the inboard caliper web, a measure of the remaining thickness of the brake pads.

Abstract: An alarm device for a brake clearance limit in an air-over-hydraulic brake system wherein air pressure piston drives a hydraulic piston for producing braking hydraulic pressure in a hydraulic brake system, capable of giving a warning at a certain constant brake clearance, irrespective of the height of pressure in the hydraulic brake system. The device comprises a sensor of hydraulic pressure for detecting a hydraulic pressure P in the hydraulic brake system, a sensor of shift amount l of the air-pressure piston after the moment when the permissible limit of brake clearance has been reached and all of the gaps in the hydraulic brake system have been lost, and a warning element which gives a warning signal when a formula l>.alpha..multidot.P is satisfied, wherein .alpha. designates rigidity coefficient of the hydraulic brake system, i.e., a quotient of the increased shift amount of the hydraulic piston divided by the increased amount of the hydraulic pressure.

Abstract: A friction lining wear indicator for shoe-drum brakes comprising a sensor mounted on a brake shoe, which actuates an indicator when the thickness of a friction lining carried by a platform of the shoe for engagement with a drum is less than a predetermined value. In order to locate the sensor at the most effective position without machining the lining or fastening the sensor permanently to the shoe, the sensor is located by a mounting device located in a depression in an edge of the platform, and co-operates with the shoe to retain the sensor adjacent the lining. The mounting device comprises a plastics plug, or a resilient clip, and the retaining device is releasable. The sensor comprises a wire loop or a pressed insulation-coated metal strip, and may be integral with the mounting device. The sensor and the drum are connected in a circuit with the indicator which is actuated when the sensor touches the drum.

Abstract: A sensor device, for fitting to, for example, a drum brake shoe includes a loop of wire which can electrically contact the drum to provide a signal to indicate wear. After a predetermined amount of wear of the shoe lining, the wire contacts the drum on each brake application to provide an intermittant warning signal. When the lining becomes dangerously worn, the loop is severed and the ends spring apart so as to maintain contact with the drum and provide a continuous signal. The wire is mounted in a housing of plastics or of sheet metal, which may be a snap-fit in to the shoe structure.

Abstract: A brake booster consisting of a power cylinder and a hydraulic cylinder in combination and a wear detector for detecting a predetermined extent of wear of a brake lining is disclosed, which comprises the wear detector being formed of a switch operating member provided with a spring at one end and adapted to be moved by the action of a power piston in the power cylinder, a switch to be actuated due to the movement of the switch operating member and means apparatus for exerting a pressure corresponding to the operating pressure of the power piston on the other end of the switch operating member so that the switch operating member can be moved by the action of the power piston through the spring.

Abstract: A disc brake including a stationary member secured to a non-rotatable part of a vehicle, and a friction pad disposed on each side of a rotatable disc. There is provided a wear warning piece one end of which is secured to the stationary member and the other end of which extends between the disc and a backing plate of the friction pad by a predetermined distance.

Abstract: A clutch or brake protection device for use with a clutch having relatively axially movable components, the device including an element mounted on one of the components and situated adjacent to the other of the components, the position of the element being such that it will contact the said other component when wear in the clutch or brake in excess of a predetermined amount has taken place, to complete electrical connection and provide a signal indicating the condition of the clutch or brake.

Abstract: A warning circuit which generates signals in response to selected conditions of a vehicle hydraulic brake system. The brake system includes an engine-driven main source of hydraulic pressure, a relay-actuated auxiliary source of hydraulic pressure, a flow sensor for sensing the operation of the main source and a brake switch for coupling the auxiliary source with the battery in response to an operator brake application. The warning circuit includes a first transistor switch coupled with a warning lamp, with the ignition switch and with the auxiliary source. A second transistor switch is coupled to the ignition switch, to the auxiliary relay, to the flow sensor and to the first transistor switch. A third transistor switch is coupled to the ignition swtich, to the flow sensor and to the first transistor switch. The system actuates the auxiliary source upon failure of the main source during an operator brake application.

Abstract: A warning circuit generates warning signals in response to a blown fuse in a vehicle brake system which includes primary and ignition-switch controlled. The back-up pump is driven by an electric motor. Control circuitry monitors and controls the brake system and the fuse protects the control circuitry from ground fault conditions. The warning circuit includes a warning lamp which is connected to the battery via the ignition switch and which is grounded through a transistor switch. The transistor switch is resistively coupled to ground and to the vehicle battery through the fuse so that the transistor switch becomes conducting to actuate the lamp upon the blowing of the fuse. Alternatively, a similar transistor switch may be connected to the output of an astable multivibrator, which in turn is connected to the battery via the fuse and whose output is inhibited unless the fuse blows while the ignition switch is closed.

Abstract: Parking brake release apparatus for a vehicle of the type which has a frame, wheels, a parking brake for at least one of its wheels, a parking brake pedal pivotally mounted to the frame to apply the parking brake, the pedal having a braking and a brake release condition, a brake return opposing braking movement of the parking brake pedal, and an engine to provide driving power to at least one of the wheels. The engine when operating has a range of possible rotational frequencies (rpm). The release apparatus itself comprises a releasable lock adapted to lock the parking brake pedal in its braking condition. A lock release is adapted selectively to release the lock means and to prevent the lock means from locking.

Abstract: A boundary responsive wheel lock assembly for a supermarket shopping cart, or the like, or for any other application where a wheeled device is to be boundary responsive, is provided, to prevent the removal of the cart from an authorized area. The assembly includes a roller which is mounted on the distal end of an arm which, in turn, is pivotally mounted to a bracket to be positioned adjacent to one of the wheels of the cart. A spring-loaded plunger is also mounted on the bracket, and the plunger is normally held in a cocked position by the arm as the roller moves along the floor of the supermarket or along the surface of the adjacent parking lot. The parking lot is surrounded by a barrier which extends, for example, one and a half inches above the ground. However, the flexibility of the assembly of the invention enables the assembly to respond to a variety of boundary heights.