Disc brake system with ABS
First Claim
1. A vehicle wheel brake system for a wheel suspension assembly and having an anti-lock braking system (“
- ABS”
) to provide a higher resolution brake apply and brake release relative to an ABS system having a single, fixed brake disc, the brake system comprising;
a mounting hub for a road wheel mounted on the wheel suspension assembly for rotation about a rotational axis;
at least two slidable brake discs mounted to slide axially along the hub between braking and off-brake positions;
a caliper including a fixed bridge and at least four (4) braking pads mounted on the fixed bridge to provide four braking surfaces for braking engagement with the opposing sides of each of the brake discs;
a pulse creator mounted on the hub for generating pulses;
a sensor mounted on the wheel suspension assembly for sensing pulses from the pulse creator and for providing signals with respect to the rotational condition of the road wheel;
an ABS controller connected to the sensor and providing signals when the wheel condition is within preset parameters relative to the speed of the vehicle to develop a theoretical deceleration curve for the stopping of the vehicle within a predetermined distance; and
a brake actuator system operable manually by the vehicle passenger and operable automatically by the ABS controller to operate the caliper to slide the brake discs axially and to cause application of the four brake pads at a pressure of about one-half or less of the pressure of operation of the fixed, brake disc system and a frequency of brake apply and release of at least double the frequency of brake apply and release of the fixed, brake disc system.
1 Assignment
0 Petitions
Accused Products
Abstract
An ABS brake system employs two axially slidable brake discs and four brake pads that are biased to have floating light random contact therebetween in the off brake position. The ABS controller operates the brake pads with about one half of the usual brake pressure and about double the number of the usual braking and release cycles. The floating axially slidable brake discs and four brake pads have reduced residual torque drag during the brake release cycle and have reduced hystersis. The result is operation at a higher frequency and with less amplitude, than the usual sliding caliper and fixed brake system, and a resolution of a modulating scale for cycling that is usually associated with a much lower coefficient of friction surface than is actually present.
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Citations
26 Claims
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1. A vehicle wheel brake system for a wheel suspension assembly and having an anti-lock braking system (“
- ABS”
) to provide a higher resolution brake apply and brake release relative to an ABS system having a single, fixed brake disc, the brake system comprising;a mounting hub for a road wheel mounted on the wheel suspension assembly for rotation about a rotational axis;
at least two slidable brake discs mounted to slide axially along the hub between braking and off-brake positions;
a caliper including a fixed bridge and at least four (4) braking pads mounted on the fixed bridge to provide four braking surfaces for braking engagement with the opposing sides of each of the brake discs;
a pulse creator mounted on the hub for generating pulses;
a sensor mounted on the wheel suspension assembly for sensing pulses from the pulse creator and for providing signals with respect to the rotational condition of the road wheel;
an ABS controller connected to the sensor and providing signals when the wheel condition is within preset parameters relative to the speed of the vehicle to develop a theoretical deceleration curve for the stopping of the vehicle within a predetermined distance; and
a brake actuator system operable manually by the vehicle passenger and operable automatically by the ABS controller to operate the caliper to slide the brake discs axially and to cause application of the four brake pads at a pressure of about one-half or less of the pressure of operation of the fixed, brake disc system and a frequency of brake apply and release of at least double the frequency of brake apply and release of the fixed, brake disc system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
springs between the hub and inner portions of the slidable brake discs to mount the brake discs in a floating manner on the hubs; and
springs on the fixed caliper for holding the brake pads in position relative to the brake pads during vehicle wheel speed-up.
- ABS”
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4. A vehicle wheel ABS braking system in accordance with claim 1 having reduced weight and reduced residual drag torque, comprising:
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a hollow, cylindrical bore formed in the suspension member having a force actuator contained therein;
springs floating and supporting the slidable brake discs on the hub; and
springs on the caliper for engaging the slidable brake pads and for holding them in position relative to the slidable brake discs in the off-brake position to reduce residual torque drag therebetween.
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5. A vehicle wheel braking system, in accordance with claim 1, wherein the brake actuator system comprises:
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an integral, hydraulic cylinder for holding a hydraulic fluid integrally formed in a suspension member of the wheel suspension; and
a piston mounted in the integral hydraulic cylinder and is operable by the hydraulic system to engage the four brake pads with the two axially, slidable brake discs.
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6. A vehicle wheel ABS braking system, in accordance with claim 1, wherein the brake pad actuator comprises a solenoid and an electrical system for selectively energizing and de-energizing the solenoid.
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7. A vehicle wheel ABS braking system, in accordance with claim 1, wherein the brake actuator comprises:
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a hydraulic system having a hydraulic cylinder at each wheel;
a hydraulic reservoir for containing hydraulic fluid at each of the ABS-controlled brake pads to supply hydraulic fluid to an adjacent, hydraulic cylinder; and
a pressure generator at each wheel suspension operable by the mass of the vehicle for pressuring the hydraulic fluid in each hydraulic reservoir.
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8. A vehicle wheel ABS braking system, in accordance with claim 1, wherein the pulse generator comprises a ring of spaced generator elements mounted on a side of the rotatable hub;
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the sensor comprises a magnetic sensor disposed on the suspension member closely adjacent the ring of spaced generator elements.
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9. A vehicle wheel ABS braking system, in accordance with claim 1, wherein the caliper is mounted on the suspension member in a vertical plane through the rotational axis and above the rotational axis and a radially outer position relative to the rotational axis;
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the pulse generator and the sensor are located radially inwardly of the caliper.
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10. A vehicle disc brake and suspension system having an ABS system comprising:
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a wheel suspension member having a hub and connections to other portions of the vehicle steering device;
at least two brake discs each having an inner portion slidably mounted on the hub for sliding in a direction parallel to the central axis of the hub between a braking position and off-brake position;
at least four braking pads including one outer, fixed, brake pad and at least three slidable brake pads each having a friction pad surface for applying braking torque to opposite sides of the brake disc when in the braking torque position to decelerate the engaged brake discs;
a hollow bore in the suspension member;
an actuator in the hollow bore of the suspension member for sliding the slidable brake pads and brake discs into the braking position;
force applicators for floating the brake discs to allow them to slide axially from a braking position to an off-braking position relative to the braking pads;
an outer rim portion on the braking disc rotating while in the off-brake position and engaging the slidable brake pad'"'"'s friction surface to slide the pad from the braking position to an off-brake pad position;
a caliper fixed to the suspension member and having slidable brake pads thereon operable by the actuator into braking engagement with the slidable brake discs;
a brake pad force applicator acting on the slidable brake pads, when its off-brake position, to constrain the friction pad surfaces engaging the brake disc to reduce tilting of the brake pads on the stationary support and its rubbing on the brake discs that would increase off-brake, residual torque; and
an ABS system for operating the brake pad force applicator within the hollow bore in the suspension member to slide the brake pads and brake discs iteratively to the braking position and releasing the brake pads and discs to slide to off-brake positions. - View Dependent Claims (11, 12, 13, 14, 15, 16)
the slidable brake pad comprises a slidable pad carrier mounted for sliding on the bridge and carrying the frictional pad surface thereon; and
the brake pad force applicator is positioned over the brake pad carrier and forces the brake pad carrier downwardly against the bridge.
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17. A vehicle wheel suspension system having an ABS braking system comprising:
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a suspension member;
at least one brake disc mounted on the suspension member for rotation with a wheel of the vehicle, brake pads mounted on the suspension member for movement to a brake application position to engage the at least one brake disc to decelerate the wheel and for movement to a brake release position to allow the wheel to accelerate during an ABS braking operation;
a localized hydraulic system at each of a plurality of wheels without connection to a master cylinder for shifting the brake pads to the brake application position and for allowing the brake pads to shift to the brake release position;
a hydraulic reservoir mounted on the suspension at each wheel for containing hydraulic fluid;
a pressure generator at each wheel suspension independent of a connection to a master cylinder for an associated hydraulic reservoir operable by the vehicle mass movement to increase pressure in the reservoir; and
an ABS control system including an electrically operated actuator at each wheel suspension for operating the localized hydraulic system at each wheel suspension to iteratively shift the brake pads into the brake application position with vehicle wheel acceleration with intervals therebetween of wheel acceleration to stop the vehicle. - View Dependent Claims (18, 19, 20)
wherein four brake pads are mounted on the suspension member to engage four faces of the pair of brake discs.
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19. A vehicle suspension and ABS braking system, in accordance with claim 17, wherein the hydraulic system comprises:
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an integral, hollow cylinder formed in a stub axle suspension member; and
a piston mounted in the integral, hollow cylinder.
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20. A vehicle suspension and ABS braking system, in accordance with claim 17, wherein the ABS control system comprises an intelligent control located at each wheel for controlling that wheels iterative brake application and brake release.
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21. A method of braking a vehicle wheel using an ABS system having an ABS hydraulic system and an ABS controller, and a wheel brake having a caliper and at least two of slidable brake discs axially slidable on a rotatable wheel supporting hub and having at least four brake pads engageable with the brake discs, the method comprising:
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operating the caliper to a braking position using 40 BAR or less of hydraulic fluid pressure to slide the brake pads and the slidable brake discs to a braking position;
releasing the hydraulic fluid to allow the slidable brake discs to slide axially on the hub and to engage the slidable friction pads and to push them to their off-brake positions;
floating the brake discs and the brake pads on their respective supports in the off-brake position to reduce off-brake frictional drag and tilting of this brake pads against the brake discs;
sensing operation of a brake pedal by the operator generating an excessive braking force and sensing wheel speed and an approaching lock up of the road wheel using an ABS controller;
activating the ABS hydraulic system by the ABS controller to shift the slidable brake pads on the fixed caliper with hydraulic pressure at 40 BAR or less; and
shifting slidable brake pads and slidable brake discs on their floating supports rapidly to the braking position with changes in pressure from 40 BAR and at a predetermined frequency in accordance with a stored algorithm in the ABS system. - View Dependent Claims (22, 23, 24, 25, 26)
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Specification