Abstract: A vehicle braking system of the type having individually controlled brakes with respective angularly fixed (17, 19) and rotatable (11) friction surfaces urged into contact by an operator initiated (35, 65) braking force for each of a plurality of rotatable vehicle wheels has braking torque variations within a wheel revolution alleviated for each wheel by sensing variations in braking force (45, 71) as a function of wheel angular position (49, 77) during a complete vehicle wheel revolution and initiating (59) a reduction in braking force during a subsequent wheel revolution prior to the wheel reaching an angular position (87) at which an increase in braking force was sensed during a previous wheel revolution. A particular wheel angular position may be identified as a reference position and data indicative of the sensed variations stored (51, 75) as a function of wheel angular position relative to the reference position.

Abstract: An adaptation to a vehicle antilock braking system modulator to increase the initial displacement of the master cylinder, provide quicker system response and improved pedal feel. A solenoid assembly is added to the non fluid side of each of the low pressure accumulators in the ABS modulator. Upon the operator initiation of a brake apply, the solenoids are energized to immediately push upon the sump pistons and inject fluid from the low pressure accumulators into the brake system. This extra “shot” of fluid decreases the amount of fluid that the master cylinder delivers to the brake system. This improves pedal feel as it reduces the required initial pedal travel for a given brake system displacement. The low pressure accumulator pistons are spring balanced to ensure retention of fluid between brake applies and to allow normal ABS operation. During ABS operation, the low pressure accumulator displacer solenoids are de-energized to allow effective operation.

Abstract: A lever for moving first and second brake shoes into engagement with a drum to effect a brake application. The lever has a first end connected to the brake shoes and a second end with a tine fixed thereto to which a cable is connected to apply an input force to effect a brake application. A predetermined force is applied to the tine to deflect the tine and a tab engages the lever to hold the tine in the deflected position. The tine and second end of the lever move in unison in response to an input force until the input force exceeds the predetermined force such that while the tine and cable continue to move in unison the deflection of the tine proportionally reduces the movement of the first end of the lever and as a result an actuation force applied to effect a brake application is correspondingly reduced.

Abstract: A drum brake has cylinders symmetrically fixed to a stationary member. Each cylinder has an axial bore therein with a groove for retention of a seal. A piston engages each seal to define chambers that receive pressurized fluid. Webs for friction members have a first end pined to an opposite cylinder and a second end connected to an opposite piston and to each other by a strut. Pressurized fluid acts on the pistons to move the second ends with respect to the first ends and simultaneously bring the friction members into engagement with a drum to effect a brake application. The seals acts on and return the pistons to a rest position in an absence of pressurized fluid. A pawl on a lever is moved into engagement with the strut to bring the first and second friction members into engagement with the drum to manually effect a brake application.

Abstract: A disc brake has a support with a first end separated from a second end by first and second side walls that retain actuation members to move the first and second friction members into engagement with a rotor and effect a brake application. First and second perpendicular projections that extend from the support are aligned with the first wall and third and fourth perpendicular projections that extend from the support and are aligned with the second wall. The first and second friction members have first and second radial projections located between a first end and a second end. Beams connect the radial projections with the perpendicular projections to align the first and second friction members with the rotor and pivot on the perpendicular projections to carry reaction forces created during a brake application into the first end of the support.

Abstract: A disc brake has an anchor that is fixed to a housing to align first and second rails and friction pads for each of first and second friction members with radial surfaces on a rotor. The friction pads are moved into engagement with radial surfaces by an actuation force to develop a brake force and reaction forces that are carried into the anchor to oppose the rotation of the rotor during a brake application. The anchor has projections on the first rail located in planes that are offset from radial engagement surfaces on the rotor. The friction members each have a carrier with an outwardly projecting lip on a first end through which the brake forces are transmitted into the projections. Since the projections are offset a moment is created by the reactions forces and an axial component derived thereof added to the actuation force during a brake application.

Abstract: A control valve for a brake booster having a first member with a first bore, a second member located in the first bore and having a second bore, a plunger located in the second bore and connected to an input member. A gear fixed to the second member with teeth that engage a first rack retained in the first body and a stationary rack within the brake booster. A force applied to the input member controls the development of a pressure differential that moves a wall during a brake application. Movement of the wall causes a rotative torque to be transmitted from the first rack into teeth such that the gear moves with respect to the second rack and the second body to separates from the first body and as a result the travel of input member is less than the travel of the wall during a brake application.

Abstract: A master cylinder wherein an input force applied to a bearing assembly pushes and rotates an input piston into a bore of a housing through the engagement between a helical groove on its outer surface and a pin on the housing to act on a primary piston in the bore that supplies pressurized fluid to wheel brakes. A threaded connection that connects the input piston to a primary master cylinder piston has an opposite direction thread from that of the helical groove in the input piston and as a result the input piston moves at a different rate of travel within the bore than the primary piston such that initial movement of the input piston is accentuated in the movement of primary piston and after a predetermined travel of the input piston into the bore, the input piston and primary piston travel in unison to effect a brake application.

Abstract: A support for a disc brake has first and second bores in a first projection and third and fourth bores in a second projection located in a same horizontal plane and the first and third bores aligned in a first vertical plane and the second and fourth bores aligned in a second vertical plane. A first pin retained in the first and third bores extend through a first lever to position a first friction member adjacent a rotor while a second pin extends through the second and fourth bores to position a second friction member adjacent the rotor. Pressurized fluid is supplied to act on a piston retained in the first lever such that the first lever pivots on the first pin and the second lever pivots on the second pin to thereafter move the first and second friction members into engagement with the rotor and effect a brake application.

Abstract: A brake actuating assembly includes a cam member that has first and second cam surfaces. A first piston in a first hydraulic circuit is selectively enabled to axially translate the cam member from a released position to an actuation position while an actuation piston moves friction surfaces into engagement with a rotor to effect a brake application. During a brake application, pressurized fluid is diverted away from a second piston in a second hydraulic circuit that is later enabled to return the cam member to the released position. A resilient assembly selectively engages the second cam surface to obliquely move the cam member toward the actuation piston during a brake application. An electrically actuable valve supplies pressure fluid that acts on and moves the resilient assembly away from the second cam surface and thereafter allow a second hydraulic piston to return cam member to the released position.

Abstract: A master cylinder having a housing with first and second bores that are connected to a same circuit in a braking system. A first piston is sealingly retained in the first bore to define a first chamber and a second piston is sealingly retained in the second bore to define a second chamber. The first piston has of a first cylindrical member that is connected to a second cylindrical member by a shaft. The shaft includes an actuation and a retraction ramp that terminate at an apex. An input force applied to the second cylindrical member is directly applied through the shaft to the first cylindrical member and through the actuation and retraction ramps to the second piston to respectively communicate fluid simultaneously to the same circuit.

Abstract: An anchor having first and second rails to align first and second friction members with a rotor. The first and second friction members are moved into engagement with the rotor to effect a brake application. The anchor has projections that extend from the first and second rails and are aligned with the rotor. The thickness of a friction member is reduced by wear through the engagement with the rotor. Each friction member is attached to a carrier by a first inwardly projecting lip on a first end and a second inwardly projecting lip on a second end that has a length that corresponds to an initial thickness of a friction pad plus one-half the width of a projection. During a brake application the lips either engage projections on the first rail or projections on the second rail such that braking forces are communicated into the anchor without the introduction of a moment that could effect the uniform application of force from the friction member on the rotor.

Abstract: A hydraulic system (10) having a pump (12) for sequentially supplying a brake booster (14) and a steering gear (16) with hydraulic fluid to an assist in effecting a brake application and/or a steering application. The brake booster (14) has a housing (100) with a chamber (102) therein connected to a first bore (104) which retains a piston (108) connected to a master cylinder (112) and a second bore (106) which retains a control valve (114). The second bore (106) has an inlet port (118) connected to the pump (12) for receiving supply hydraulic fluid, an outlet port (120) connected to the steering gear (16) and a return port (120) connected to the pump (12).

Abstract: The hydraulic and electric powered parking brake system (10) comprises a redundant or simultaneous operation of the system (10) to meet Federal Safety Standards. A dash mounted control knob (24) operates a hydraulic brake application mechanism (20) which transmits a hydraulic pressure to a hydraulically operated pilot piston (70). The control knob (24) also operates a switch (30) to send an electrical signal to an electrical control unit (100) which sends an electrical signal to a solenoid (80). The solenoid (80) and hydraulic pilot piston (70) can be operated, independently or simultaneously, to displace a control valve (60) located within a parking actuator assembly (114) and effect the release of hydraulic pressure from spring apply and hydraulic release actuators (16, 90) connected to vehicle brakes (18). The hydraulic fluid is released past the control valve (60) and to a reservoir (52).