Abstract: A system and method for evaluating characteristics of an S-cam are provided. The inventive method includes the step of obtaining angle values and displacement values indicative of an angle of rotation of the S-cam and displacement of a cam follower caused by rotation of a lobe of the S-cam. The method further includes the step of determining a profile for the lobe of the S-cam responsive to the angle values and the displacement values. The method further includes the steps of computing a deviation of the profile from a desired profile for the lobe of the S-cam and determining a rate of change in the deviation of the profile. In addition, the system and method may evaluate characteristics such as the concentricity of the S-cam and power transfer characteristics of the S-cam.

Abstract: A spring-type brake actuator for a pneumatically-operated vehicle brake is provided, in which the portion of the brake actuator containing the parking brake actuation power spring is arranged to be vented to atmosphere but not to permit entry of outside environmental air into the power spring chamber, the spring-type brake actuator being provided with an internal breather valve which permits clean dry air from the parking brake release chamber to enter the power spring chamber which the pressure difference between the chambers falls to within a predetermined pressure range.

Abstract: A brake includes a pair of lever brake shoes and a pair of idler brake shoes. The lever brake shoes are each pivotally coupled to a brake spider at a first end. The idler brake shoes are each pivotally coupled to the brake spider at a first end and to corresponding ones of the first and second lever brake shoes at a second end. The pivotal connections to the brake spider may be different for each of the lever and idler brake shoes. An actuating member engages the second end of each of the lever brake shoes and causes the lever brake shoes and idler brake shoes to move between positions of engagement and disengagement with a braking surface. The linings on the lever brake shoes may be circumferentially nearer to the first ends of each shoe than the second end of each shoe.

Abstract: A brake shoe for a drum brake includes an arcuate brake table defining radially inner and outer sides. First and second webs are disposed on the radially inner side of the brake table and configured to support the brake table. One or more brake linings are disposed on the radially outer side of the brake table. In one embodiment, the brake table defines a plurality of fins projecting radially inwardly from the radially inner side of the brake table, each of the plurality of fins having a length in a radial direction. In another embodiment, the brake table is a unitary body and is configured at first and second ends and a point intermediate the first and second ends to engage first and second brake linings and prevent circumferential movement of the first and second brake linings relative to the brake table. The brake table may comprise extruded aluminum.

Abstract: An improved self-adjusting automatic slack adjuster for reducing slack in the brake of a vehicle is provided, in which an easily accessible external operating feature permits the automatic slack adjuster's one-way clutch assembly to be readily disengaged to allow smooth release and retraction of the brake shoes of a vehicle brake without damage to the one-way teeth of the clutch assembly. When the external feature is operated in a brake release direction, the motion of the feature is translated into a motion which axially displaces an output part of the one-way clutch away from an input part of the clutch a distance sufficient to disengage the parts' one-way teeth, thereby disengaging the one-way clutch to permit brake shoe retraction without resistance from the one-way clutch.

Abstract: A system and method are provided for mounting, removing and retaining brake pads in disc brakes, such as air-operated disc brakes utilized on commercial vehicles, in a manner which does not require the use of separate brake pad retaining devices while providing positive retention of the brake pad. A preferred embodiment includes a brake caliper mount having brake pad abutment surfaces having radially-oriented and lateral grooves which permit a brake pad with corresponding projections on is lateral sides to be inserted through an opening of the brake caliper into the radially-oriented grooves until the backing plate projections are aligned with the lateral groove, and advancing the brake actuator behind the brake pad to place the brake pad in an operating position in which the actuator prevents the brake pad from realigning with the radially-oriented grooves until the actuator is retracted to permit brake pad extraction.

Abstract: system and method are provided for mounting, removing and retaining brake pads in disc brakes, such as air-operated disc brakes utilized on commercial vehicles, in a manner which does not require the use of separate brake pad retaining devices while providing positive retention of the brake pad. A preferred embodiment includes a brake caliper mount having brake pad abutment surfaces having radially-oriented and lateral grooves which permit a brake pad with corresponding projections on is lateral sides to be inserted through an opening of the brake caliper into the radially-oriented grooves until the backing plate projections are aligned with the lateral groove, and advancing the brake actuator behind the brake pad to place the brake pad in an operating position in which the actuator prevents the brake pad from realigning with the radially-oriented grooves until the actuator is retracted to permit brake pad extraction.

Abstract: A system and method are provided for mounting, removing and retaining brake pads in disc brakes, such as air-operated disc brakes utilized on commercial vehicles, in a manner which does not require the use of separate brake pad retaining devices while providing positive retention of the brake pad. A preferred embodiment includes a brake caliper mount having brake pad abutment surfaces having radially-oriented and lateral grooves which permit a brake pad with corresponding projections on is lateral sides to be inserted through an opening of the brake caliper into the radially-oriented grooves until the backing plate projections are aligned with the lateral groove, and advancing the brake actuator behind the brake pad to place the brake pad in an operating position in which the actuator prevents the brake pad from realigning with the radially-oriented grooves until the actuator is retracted to permit brake pad extraction.

Abstract: An automatic slack adjuster one-way clutch includes a first part, which is rotatable about an axis in both a drive direction and a slip direction opposite to the drive direction, and a second part, which is driven about the axis by the first part only when the first part rotates in the drive direction. The second part is not driven by the first part when the first part rotates in the slip direction. Multiple movable teeth, carried by one of the parts, are displaceable axially relative to both of the parts and engage between teeth immovably fixed on the other of the parts. The first part may be either an input part or an output part of the clutch.

Abstract: A cast iron brake caliper with improved fatigue life, and a process and process equipment for pre-stressing a cast iron brake caliper to provide improved fatigue life, is provided. In the process, a load is applied to a cast iron caliper, where the load is high enough to locally yield and plastically deform the cast iron material, but not high enough to cause material failure, such as cracking. Upon load removal, residual compressive stresses in the cast iron caliper lower the mid-point of the stress range the plastically-deformed region of the caliper sees during in-service use, and thereby lowers the peak stress seen in this region, increasing fatigue life. The process permits a cast iron brake caliper to be designed to use less material and thus fit within constrained wheel rim envelopes, without the need to resort to high cost materials or other alternative design strategies.

Abstract: A system and method are provided for mounting, removing and retaining brake pads in disc brakes, such as air-operated disc brakes utilized on commercial vehicles, in a manner which does not require the use of separate brake pad retaining devices while providing positive retention of the brake pad. A preferred embodiment includes a brake caliper mount having brake pad abutment surfaces having radially-oriented and lateral grooves which permit a brake pad with corresponding projections on is lateral sides to be inserted through an opening of the brake caliper into the radially-oriented grooves until the backing plate projections are aligned with the lateral groove, and advancing the brake actuator behind the brake pad to place the brake pad in an operating position in which the actuator prevents the brake pad from realigning with the radially-oriented grooves until the actuator is retracted to permit brake pad extraction.

Abstract: A system and method are provided for mounting, removing and retaining brake pads in disc brakes, such as air-operated disc brakes utilized on commercial vehicles, in a manner which does not require the use of separate brake pad retaining devices while providing positive retention of the brake pad. A preferred embodiment includes a brake caliper mount having brake pad abutment surfaces having radially-oriented and lateral grooves which permit a brake pad with corresponding projections on is lateral sides to be inserted through an opening of the brake caliper into the radially-oriented grooves until the backing plate projections are aligned with the lateral groove, and advancing the brake actuator behind the brake pad to place the brake pad in an operating position in which the actuator prevents the brake pad from realigning with the radially-oriented grooves until the actuator is retracted to permit brake pad extraction.

Abstract: A fluid pressure operable actuator includes a housing, with an end wall, and a pushrod projecting through an opening in the end wall for reciprocation upon service pressure application or release. A shield, configured as an annulus, is disposed on the pushrod to restrict contamination of an interior chamber of the actuator housing through a gap existing between an edge of the opening and a pushrod outer surface. To facilitate connecting the shield and the pushrod together, the annulus has a slit with an enlarged void at a radially outer end of the slit. This enlarged void engages an outer pushrod surface as the shield and the pushrod are joined.

Abstract: An improved self-adjusting automatic slack adjuster for reducing slack in the brake of a vehicle is provided, in which an easily accessible external operating feature actuates a ball detent clutch to permit the automatic slack adjuster's adjustment mechanism to be readily disengaged, so as to allow smooth release and retraction of the brake linings of a vehicle brake without damage to the adjustment mechanism's components. When the torque applied to the external feature exceeds a predetermined torque, the balls of the ball detent clutch move out of their retaining detents, thereby disengaging the slack adjuster's worm shaft from the adjustment mechanism and permitting brake shoe retraction without resistance from the adjustment mechanism.

Abstract: A brake actuator having a plurality of actuator housing portions includes a diaphragm seal partially delimiting a parking brake de-actuation chamber and retained between adjacent portions of the housing. To produce brake actuation upon depressurization of the parking brake de-actuation chamber, a push rod extends into and out of a service brake actuation chamber upon release of fluid pressure from and supply of fluid pressure to the chamber. A clip or similar element receivable over the end section of the push rod is securable on the end section to compress the diaphragm seal axially relative to the push rod against a seat carried by the push rod while permitting a radial inner edge of the diaphragm seal to remain spaced from an outer surface of the end section.

Abstract: An apparatus and method for preventing parking brake-caused disabling of a vehicle is provided. In at least one of the vehicle's parking brake release actuators' supply lines there is provided a flow arrangement which allows parking brake release fluid to flow to and from the release actuator when its supply line is undamaged, and restricts flow from the release pressure source when the line between the flow arrangement and the actuator is damaged. The flow arrangement may be a pilot-operated, non-graduated control valve, a combination of a pressure protection valve and a check valve arranged in parallel, a velocity-sensing check valve, or any other device or combination of devices which provide the damaged line shutoff or metering functionality. Such an arrangement prevents automatic application of the parking brake by releasing pressure from all of the vehicle's parking brake actuators, thereby precluding automatic vehicle immobilization following damage at one wheel end.

Abstract: A cast iron brake caliper with improved fatigue life, and a process and process equipment for pre-stressing a cast iron brake caliper to provide improved fatigue life, is provided. In the process, a load is applied to a cast iron caliper, where the load is high enough to locally yield and plastically deform the cast iron material, but not high enough to cause material failure, such as cracking. Upon load removal, residual compressive stresses in the cast iron caliper lower the mid-point of the stress range the plastically-deformed region of the caliper sees during in-service use, and thereby lowers the peak stress seen in this region, increasing fatigue life. The process permits a cast iron brake caliper to be designed to use less material and thus fit within constrained wheel rim envelopes, without the need to resort to high cost materials or other alternative design strategies.

Abstract: A spring-type brake actuator for a pneumatically-operated vehicle brake is provided, in which the parking brake release piston is formed from at least one stamped actuator piston plate, preferably a stamped aluminum plate. Preferably the biasing force of the power spring of the spring brake actuator bears on a stamped spring seat cap element which is interposed between the power spring and the stamped actuator piston plate. In addition, the parking brake release piston flexible diaphragm may be captured between the stamped actuator piston plate and a stamped backing plate by affixing the backing plate to a joining member, where the joining member includes a threaded insert to receive a manually-actuated parking brake release actuation tool.

Abstract: In a brake actuator including a plurality of actuator housing portions, a diaphragm seal, partially delimiting a parking brake de-actuation chamber, is retained between adjacent actuator housing portions, and an elastic element disposed between the diaphragm seal and one of the housing portions opposes expansion of the parking brake de-actuation chamber. A push rod extends into and out of a service brake actuation chamber upon respective release of fluid pressure from the parking brake de-actuation chamber and supply of fluid pressure to the parking brake de-actuation chamber. In order to constrain a central portion of the diaphragm seal for movement together with both the push rod and a piston, a clamping arrangement is used to axially clamp the central diaphragm seal portion between an end of the push rod and a surface of the piston.

Abstract: A spring-type brake actuator for a pneumatically-operated vehicle brake is provided, in which the portion of the brake actuator containing the parking brake actuation power spring is arranged to be vented to atmosphere but not to permit entry of outside environmental air into the power spring chamber, the spring-type brake actuator being provided with an internal breather valve which permits clean dry air from the parking brake release chamber to enter the power spring chamber which the pressure difference between the chambers falls to within a predetermined pressure range.