Anti-lock brake system

Claim 2

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing hydraulic operating fluid, and a hydraulic fluid reservoir, the combination of: a plurality of piston means, each being fluidly connected to a wheel brake or set of wheel brakes for actuation thereof in proportion to an operating fluid pressure acting on the respective piston means; brake control valve means normally communicating operating fluid at reservoir pressure to the plurality of piston means and including operator acTuable means adapted to actuate the brake control valve means to channel pressurized operating fluid to each of the piston means and to act on the brake control valve means to provide a reaction force thereon; anti-lock control valve means associated with at least one of the piston means and normally communicating thereto the pressurized operating fluid provided by the brake control valve means, the anti-lock control valve means being cyclically shifted by the wheel condition sensing and control logic signal to exhaust and re-apply the pressurized operating fluid to the piston means whereby the rate of wheel deceleration is controlled; auxiliary piston means located coaxially with each of the piston means and engageable in force transmitting therewith for actuation of the piston means independently of the operating fluid pressure acting thereon; and auxiliary master cylinder means engaged by the brake control valve means upon operator actuated overtravel thereof upon loss of reaction force provided by operating fluid pressure to provide pressure to each of the auxiliary piston means whereby the piston means are actuated in unison.

Claim 3

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means operatively engaging each of the master cylinders; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control valve means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the master cylinders; anti-lock control valve means associated respectively with at least one of the piston means and located in said conduit means fluidly intermediate the pump means and the piston means and being normally open to allow free fluid communication therebetween, the anti-lock control valve means being shifted individually by the wheel condition sensing and control logic signal to reduce and reapply operating fluid pressure acting on the piston means whereby the rate of wheel deceleration is controlled; the operating fluid pressure acting on the brake control valve means to provide a reaction force on said operator actuable means; auxiliary piston means located coaxially with each of the piston means and engageable therewith for actuation of the master cylinders independently of the operating fluid pressure acting on the piston means; and auxiliary master cylinder means engageable with and actuated by the brake control valve means upon operator actuated overtravel thereof upon loss of operating fluid flow to pressurize each of the auxiliary piston means whereby the master cylinders are actuated in unison.

Claim 4

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means operatively engaging each of the master cylinders; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control valve means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the master cylinders; anti-lock control valve means associated respectively with at least one of the piston means and located in said conduit means fluidly intermediate the pump means and the piston means and being normally open to allow free fluid communication therebetween, the anti-lock control valve means being shifted individually by the wheel condition sensing and control logic signal to reduce and reapply operating fluid pressure acting on the piston means whereby the rate of wheel deceleration is controlled; the operating fluid pressure acting on the brake control valve means to provide a reaction force on said operator actuable means; auxiliary piston means located coaxially with each of the piston means and engageable therewith for actuation of the master cylinders independently of the operating fluid pressure acting on the piston means; and auxiliary master cylinder means engageable with and actuated by the brake control valve means upon operator actuated overtravel thereof upon loss of operating fluid flow to pressurize each of the auxiliary piston means whereby the master cylinders are actuated in unison.

Claim 5

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means associated with each of the master cylinders; a push rod associated with each piston means and having a first end engaging the piston means and a second end engaging the master cylinder associated therewith, the push rod having a knob located thereon intermediate the ends; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control valve means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the mater cylinders; anti-lock control valve means associated respectively with at least one of the piston means and located in said conduit means fluidly intermediate the pump means and the piston means and being normally open to allow free fluid communication therebetween, the anti-lock control valve means being shifted individually by the wheel condition sensing and control logic signal to reduce and reapply operating fluid pressure acting on the piston means whereby the rate of wheel deceleration is controlled; the operating fluid pressure acting on the brake control valve means to provide a reaction force on said operator actuable means; lever means having a plurality of holes therethrough, the push rods extending through the holes with the lever located intermediate the piston means and the knobs; manual piston means abutting the lever and engageable with the brake control valve means upon operator actuated overtravel thereof upon loss of operating fluid flow to actuate the master cylinders independently of the piston means.

Claim 6

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means associated with each of the master cylinders; a push rod associated with each piston means and having a first end engaging the piston means and a second end engaging the master cylinder associated therewith, the push rod having a knob located thereon intermediate the ends; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control valve means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the mater cylinders; anti-lock control valve means associated respectively with at least one of the piston means and located in said conduit means fluidly intermediate the pump means and the piston means and being normally open to allow free fluid communication therebetween, the anti-lock control valve means being shifted individually by the wheel condition sensing and control logic signal to reduce and reapply operating fluid pressure acting on the piston means whereby the rate of wheel deceleration is controlled; the operating fluid pressure acting on the brake control valve means to provide a reaction force on said operator actuable means; lever means having a plurality of holes therethrough, the push rods extending through the holes with the lever located intermediate the piston means and the knobs; manual piston means abutting the lever and engageable with the brake control valve means upon operator actuated overtravel thereof upon loss of operating fluid flow to actuate the master cylinders independently of the piston means.

Claim 7

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means operatively engaging each of the master cylinders; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control valve means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the master cylinders; the operating fluid pressure acting on the brake control valve means to provide a reaction force on the operator actuable means; first and second conduits in parallel flow relationship interposed in the conduit means communicating operating fluid from the fluid pump means to at least one of the piston means and including first and second anti-lock control valves located respectively in the first and second conduits, the anti-lock control valve circuit including; the first anti-lock control valve in the first conduit having a normal condition communicating operating fluid to the associated piston means and being shiftable to another condition to block fluid communication between the fluid pump means and the piston means and open fluid communication between a valve port and the fluid reservoir, the second anti-lock control valve in the second conduit having a normal condition communicating operating fluid to the associated piston means and being shiftable to another condition to block fluid communication between the fluid pump means and the Piston means and open communication between the piston means and the valve port of the first anti-lock control valve, fluid flow restricting means in the second conduit, valve operating means associated with each of the first and second anti-lock control valve and actuable by the wheel condition sensing and control logic means upon impending wheel lock condition to shift the first and second valves from the normal condition to the another condition whereby operating fluid pressure communication is blocked and the operating fluid pressure in the piston means is exhausted to the fluid reservoir to release the wheel brake, when the impending wheel lock condition has been arrested the second anti-lock control valve is shifted to the normal condition whereby communication of pressurized operating fluid is opened and the piston means actuated at a controlled rate through the fluid flow restriction means to reapply the wheel brake, and subsequent to brake reapplication the first anti-lock control valve being returned to the normal condition to reestablish unrestricted fluid communication through the first conduit.

Claim 8

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means operatively engaging each of the master cylinders; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control valve means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the master cylinders; the operating fluid pressure acting on the brake control valve means to provide a reaction force on the operator actuable means; first and second conduits in parallel flow relationship interposed in the conduit means communicating operating fluid from the fluid pump means to at least one of the piston means and including first and second anti-lock control valves located respectively in the first and second conduits, the anti-lock control valve circuit including; the first anti-lock control valve in the first conduit having a normal condition communicating operating fluid to the associated piston means and being shiftable to another condition to block fluid communication between the fluid pump means and the piston means and open fluid communication between a valve port and the fluid reservoir, the second anti-lock control valve in the second conduit having a normal condition communicating operating fluid to the associated piston means and being shiftable to another condition to block fluid communication between the fluid pump means and the Piston means and open communication between the piston means and the valve port of the first anti-lock control valve, fluid flow restricting means in the second conduit, valve operating means associated with each of the first and second anti-lock control valve and actuable by the wheel condition sensing and control logic means upon impending wheel lock condition to shift the first and second valves from the normal condition to the another condition whereby operating fluid pressure communication is blocked and the operating fluid pressure in the piston means is exhausted to the fluid reservoir to release the wheel brake, when the impending wheel lock condition has been arrested the second anti-lock control valve is shifted to the normal condition whereby communication of pressurized operating fluid is opened and the piston means actuated at a controlled rate through the fluid flow restriction means to reapply the wheel brake, and subsequent to brake reapplication the first anti-lock control valve being returned to the normal condition to reestablish unrestricted fluid communication through the first conduit.

Claim 9

In a motor vehicle having wheels, fluid pressure operated wheel brakes adapted to impart braking effort to the wheels, means providing braking pressure for operation of the wheel brakes, brake pressure controlling means responsive to pressure variations and effective to modulate braking pressure to the wheel brakes for preventing wheel lockup, pump means including a reservoir and providing fluid pressure for operation of the brake pressure controlling means, and wheel condition sensing and control logic means, a valve circuit operated by the wheel condition sensing and control logic means and adapted to provide the pressure variations for operation of the brake pressure controlling means and comprising: first and second conduits in parallel flow relationship connecting the pump means and the brake pressure controlling means; a first valve means interposed in the first conduit and having a normal condition communicating pressure from the pump means to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a first valve port and the fluid reservoir; a second valve means interposed in the second conduit and having a normal condition communicating pressure to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a second valve port and the motor; conduit means connecting the first valve port and the second valve port whereby when the first and the second valve means are both in the another condition, pressure is exhausted from the brake pressure controlling means; and when one of the valve means is in the normal condition and the other is in the another condition, the valve means in normal condition is effective to establish fluid communication with the brake pressure controlling means through the associated conduit and blocks fluid communication between the brake pressure controlling means and the reservoir.

Claim 10

In a motor vehicle having wheels, fluid pressure operated wheel brakes adapted to impart braking effort to the wheels, means providing braking pressure for operation of the wheel brakes, brake pressure controlling means responsive to pressure variations and effective to modulate braking pressure to the wheel brakes for preventing wheel lockup, pump means including a reservoir and providing fluid pressure for operation of the brake pressure controlling means, and wheel condition sensing and control logic means, a valve circuit operated by the wheel condition sensing and control logic means and adapted to provide the pressure variations for operation of the brake pressure controlling means and comprising: first and second conduits in parallel flow relationship connecting the pump means and the brake pressure controlling means; a first valve means interposed in the first conduit and having a normal condition communicating pressure from the pump means to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a first valve port and the fluid reservoir; a second valve means interposed in the second conduit and having a normal condition communicating pressure to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a second valve port and the motor; conduit means connecting the first valve port and the second valve port whereby when the first and the second valve means are both in the another condition, pressure is exhausted from the brake pressure controlling means; and when one of the valve means is in the normal condition and the other is in the another condition, the valve means in normal condition is effective to establish fluid communication with the brake pressure controlling means through the associated conduit and blocks fluid communication between the brake pressure controlling means and the reservoir.

Claim 11

In a motor vehicle having wheels, fluid pressure operated wheel brakes adapted to impart braking effort to the wheels, means providing braking pressure for operation of the wheel brakes, brake pressure controlling means responsive to pressure variations and effective to modulate braking pressure to the wheel brakes for preventing wheel lockup, pump means including a reservoir and providing fluid pressure for operation of the brake pressure controlling means, and wheel condition sensing and control logic means, a valve circuit operated by the wheel condition sensing and control logic means and adapted to provide the pressure variations for operation of the brake pressure controlling means and comprising: first and second conduits in parallel flow relationship connecting the pump means and the brake pressure controlling means; a first anti-lock control valve interposed in the first conduit and having a normal condition communicating pressure to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a first valve port and the fluid reservoir; a second anti-lock control valve interposed in the second conduit and having a normal condition communicating pressure to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a second valve port and the brake pressure controlling means; conduit means connecting the first valve port and the second valve port whereby when the first and second antilock control valves are both in the another condition fluid pressure is exhausted from the brake pressure controlling means whereby the brake pressure is reduced to allow wheel acceleration; and when one of the anti-lock control valves is in the normal condition and the other anti-lock control valve is in the another condition pressure communication between the brake pressure controlling means and the fluid reservoir is blocked and fluid communication between the pump means and the brake pressure controlling means is established through the conduit associated with the anti-lock control valve which is in the normal condition whereby fluid pressure communication is provided between the pump means and the brake pressure controlling means to selectively increase the braking pressure subsequent to a prior brake pressure decrease or to hold the level of braking pressure if not previously decreased.

Claim 12

In a motor vehicle having wheels, fluid pressure operated wheel brakes adapted to impart braking effort to the wheels, means providing braking pressure for operation of the wheel brakes, brake pressure controlling means responsive to pressure variations and effective to modulate braking pressure to the wheel brakes for preventing wheel lockup, pump means including a reservoir and providing fluid pressure for operation of the brake pressure controlling means, and wheel condition sensing and control logic means, a valve circuit operated by the wheel condition sensing and control logic means and adapted to provide the pressure variations for operation of the brake pressure controlling means and comprising: first and second conduits in parallel flow relationship connecting the pump means and the brake pressure controlling means; a first anti-lock control valve interposed in the first conduit and having a normal condition communicating pressure to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a first valve port and the fluid reservoir; a second anti-lock control valve interposed in the second conduit and having a normal condition communicating pressure to the brake pressure controlling means and being shiftable to another condition blocking communication to the brake pressure controlling means and opening communication between a second valve port and the brake pressure controlling means; conduit means connecting the first valve port and the second valve port whereby when the first and second antilock control valves are both in the another condition fluid pressure is exhausted from the brake pressure controlling means whereby the brake pressure is reduced to allow wheel acceleration; and when one of the anti-lock control valves is in the normal condition and the other anti-lock control valve is in the another condition pressure communication between the brake pressure controlling means and the fluid reservoir is blocked and fluid communication between the pump means and the brake pressure controlling means is established through the conduit associated with the anti-lock control valve which is in the normal condition whereby fluid pressure communication is provided between the pump means and the brake pressure controlling means to selectively increase the braking pressure subsequent to a prior brake pressure decrease or to hold the level of braking pressure if not previously decreased.

Claim 13

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means operatively engaging each of the master cylinders; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the master cylinders; the operating fluid pressure acting on the brake control valve means to provide a reaction force on the operator actuable means proportional to braking effort; means connecting the brake control valve means and the plurality of master cylinders whereby overtravel of brake control valve means upon loss of operating fluid flow unitarily actuates the master cylinders; first and second conduits in parallel flow relationship interposed in each of the conduit means communicating the operating fluid from the fluid pump means to each of the piston means and including first and second solenoid actuated anti-lock control valves located respectively in each of the first and second conduits, the anti-lock control valve circuit including; the first solenoid actuated anti-lock control valve means in the first conduit having a normal spring held condition communicating operating fluid to the associated piston means and being shifted to another condition upon solenoid energization to block fluid communication between the fluid pump means and the piston means and open fluid communication between a valve port and the fluid reservoir, the second solenoid actuated anti-lock control valve means in the second conduit having a normal energized condition communicating operating fluid to the associated piston means and being spring shifted to another condition upon solenoid deenergization to block fluid communication between the fluid pump means and the piston means and open communication between the piston means and the valve port of the first anti-lock control valve, fluid flow restricting means in the second conduit, the first and second anti-lock control valve means being actuable by the wheel condition sensing and control logic means upon impending wheel lock condition to shift the first and second valves from the normal condition to the another condition whereby operating fluid pressure communication is blocked and the operating fluid pressure in the piston means is exhausted to the fluid reservoir to release the wheel brake, when the impending wheel lock condition has been arrested the second anti-lock control valve being shifted to the another condition whereby communication of pressurized operating fluid is opened and the piston means actuated at a controlled rate through the fluid flow restriction means to reapply the wheel brake, and subsequent to brake reapplication the first anti-lock control valve being returned to the normal condition to reestablish unrestricted fluid communication through the first conduit.

Claim 14

In a vehicle having a plurality of wheels, fluid pressure operated wheel brakes associated respectively with the wheels for imparting braking effort thereto, wheel condition sensing and control logic means monitoring wheel deceleration and providing signals in accordance therewith, fluid pump means providing a continuous flow of operating fluid, and a fluid reservoir, the combination of: a master cylinder fluidly connected to each of the wheel brakes or set of wheel brakes for actuation thereof; piston means operatively engaging each of the master cylinders; conduit means communicating the operating fluid from the fluid pump means to each of the piston means; brake control means normally communicating the operating fluid to the fluid reservoir, whereby the operating fluid pressure acting upon each of the piston means is substantially zero; operator actuable means adapted to shift the brake control valve means to restrict fluid communication with the reservoir whereby the increase in operating fluid pressure acts on each of the piston means to simultaneously actuate each of the master cylinders; the operating fluid pressure acting on the brake control valve means to provide a reaction force on the operator actuable means proportional to braking effort; means connecting the brake control valve means and the plurality of master cylinders whereby overtravel of brake control valve means upon loss of operating fluid flow unitarily actuates the master cylinders; first and second conduits in parallel flow relationship interposed in each of the conduit means communicating the operating fluid from the fluid pump means to each of the piston means and including first and second solenoid actuated anti-lock control valves located respectively in each of the first and second conduits, the anti-lock control valve circuit including; the first solenoid actuated anti-lock control valve means in the first conduit having a normal spring held condition communicating operating fluid to the associated piston means and being shifted to another condition upon solenoid energization to block fluid communication between the fluid pump means and the piston means and open fluid communication between a valve port and the fluid reservoir, the second solenoid actuated anti-lock control valve means in the second conduit having a normal energized condition communicating operating fluid to the associated piston means and being spring shifted to another condition upon solenoid deenergization to block fluid communication between the fluid pump means and the piston means and open communication between the piston means and the valve port of the first anti-lock control valve, fluid flow restricting means in the second conduit, the first and second anti-lock control valve means being actuable by the wheel condition sensing and control logic means upon impending wheel lock condition to shift the first and second valves from the normal condition to the another condition whereby operating fluid pressure communication is blocked and the operating fluid pressure in the piston means is exhausted to the fluid reservoir to release the wheel brake, when the impending wheel lock condition has been arrested the second anti-lock control valve being shifted to the another condition whereby communication of pressurized operating fluid is opened and the piston means actuated at a controlled rate through the fluid flow restriction means to reapply the wheel brake, and subsequent to brake reapplication the first anti-lock control valve being returned to the normal condition to reestablish unrestricted fluid communication through the first conduit.