US3650573A — Antiskid brake assembly

Claim 1

Independent Claim 355 words

An automotive brake system for a vehicle having at least two pairs of running wheels, each wheel of said running wheel pairs including a brake assembly having a hydraulic actuating cylinder, a hydraulic pressure supply means for actuating said wheel brake assemblies, a first conduit means communicating said pressure supply means to the brakes of one of said wheel pairs, a second conduit means communicating said hydraulic pressure supply means with the brakes of the other of said wheel pairs, means for bringing about an impending locked condition in the other of said wheel pairs prior to bringing about an impending locked condition in said one of said wheel pairs, skid sensing means operatively connected with said other of said wheel pairs for creating a signal in response to sensing an impending skidding condition of said other of said wheel pairs, cutoff valve means connected in said first conduit means for blocking the flow of hydraulic pressure applied by said first conduit means for blocking the flow of hydraulic pressure applied by said hydraulic pressure supply means to said one of said wheel pairs, reducing valve means connected in said second conduit means for interrupting the flow of hydraulic pressure from said hydraulic pressure supply means to said other of said wheel pairs and increasing the volume of said conduit to reduce the pressure applied to said oTher wheel pairs, and control means interconnecting said skid sensing means with said cutoff valve means and said reducing valve means for actuating said cutoff valve means to maintain the hydraulic pressure at said one of said wheel pairs and simultaneously actuating said reducing valve means to allow a decrease in the hydraulic pressure applied to said other of said wheel pairs upon the sensing of an impending skid condition by said skid sensing means, whereby the hydraulic pressure applied to said other of said wheel pairs is reduced while the pressure applied to said one of said wheel pairs is maintained to allow said other of said wheel pairs to rotate while maintaining a constant braking effect on the wheels of said one of said wheel pairs.

Claim 2

Dependent Claim 355 words

An automotive brake system for a vehicle having at least two pairs of running wheels, each wheel of said running wheel pairs including a brake assembly having a hydraulic actuating cylinder, a hydraulic pressure supply means for actuating said wheel brake assemblies, a first conduit means communicating said pressure supply means to the brakes of one of said wheel pairs, a second conduit means communicating said hydraulic pressure supply means with the brakes of the other of said wheel pairs, means for bringing about an impending locked condition in the other of said wheel pairs prior to bringing about an impending locked condition in said one of said wheel pairs, skid sensing means operatively connected with said other of said wheel pairs for creating a signal in response to sensing an impending skidding condition of said other of said wheel pairs, cutoff valve means connected in said first conduit means for blocking the flow of hydraulic pressure applied by said first conduit means for blocking the flow of hydraulic pressure applied by said hydraulic pressure supply means to said one of said wheel pairs, reducing valve means connected in said second conduit means for interrupting the flow of hydraulic pressure from said hydraulic pressure supply means to said other of said wheel pairs and increasing the volume of said conduit to reduce the pressure applied to said oTher wheel pairs, and control means interconnecting said skid sensing means with said cutoff valve means and said reducing valve means for actuating said cutoff valve means to maintain the hydraulic pressure at said one of said wheel pairs and simultaneously actuating said reducing valve means to allow a decrease in the hydraulic pressure applied to said other of said wheel pairs upon the sensing of an impending skid condition by said skid sensing means, whereby the hydraulic pressure applied to said other of said wheel pairs is reduced while the pressure applied to said one of said wheel pairs is maintained to allow said other of said wheel pairs to rotate while maintaining a constant braking effect on the wheels of said one of said wheel pairs.

Claim 3

Dependent Claim 229 words

An automotive brake system as claimed in claim 1, wherein said hydraulic pressure cutoff means located in said first conduit means between said hydraulic pressure supply means and said one of said wheel pairs is comprised of a valve body, a first hydraulic passage connected between said hydraulic pressure supply means and said valve body, a second hydraulic passage connected between said valve body and said wheel brake cylinders, a chamber in said valve body connecting said first and second passages, a valve member and said second passage to urge said valve member in a closing direction, an electric solenoid assembly, including a plunger, located on that end of said valve body that is opposite to said second passage, a reciprocating stem slidably guided between said valve member and said plunger of said electric solenoid, a spring for urging said plunger, said stem, and said valve member in an open direction, whereby when said electric solenoid is actuated by said control means, said plunger will move against the force of said spring urging said valve means in the open direction, thereby allowing said valve member to move to the closed position and cut off the flow of hydraulic fluid from said hydraulic pressure supply means to said wheel brake cylinders to prevent a further increase in the pressure applied to the wheel brake cylinders of said first wheel pair.

Claim 4

Dependent Claim 327 words

An automotive brake system as claimed in claim 1, wherein said reducing valve means comprises, an incoming hydraulic conduit connected to said hydraulic pressure supply means, an outlet conduit connected to the wheel brake cylinders of said other of said wheel pairs, a passage connecting said inlet conduit and said outlet conduit, a valve means located in said passage for selectively blocking communication of said inlet passage with said outlet passage, a plunger movably positioned in said chamber between said valve means and the wheel brake cylinders of said other of said wheel pairs for varying the volume of said passage, a pneumatic servo motor means operatively connected with said valve means and said plunger, said servo motor means having a sealed cavity therein, a diaphragm piston dividing said cavity into a first and a second sealed chamber, said diaphragm piston being operatively connected with said plunger and said valve means, a first pneumatic conduit means for pneumatically communicating said first and second chambers with each other, a second pneumatic conduit means communicating said second sealed chamber with a source of pneumatic vacuum, and a change-off valve means connected in said first pneumatic conduit means, said change-off valve having a first position for communicating said first chamber with said second chamber and a second position for blocking said first pneumatic conduit means and communicating said first chamber with the ambient atmosphere, said change-off valve being actuated by said control means upon the sensing of a skid condition by said skid-sensing means to block the communication of said first chamber with said second chamber and introduce ambient atmospheric air into said first chamber to actuate said valve means to block the flow of hydraulic pressure from said hydraulic pressure supply means to said wheel brake cylinders and increaSe the volume between said valve means and said wheel brake cylinders, whereby the wheel brake actuating pressure is reduced to allow rotation of the wheels of said other wheel pair.

Claim 5

Dependent Claim 220 words

An automotive brake system as claimed in claim 1, further comprising, a pneumatic booster assembly operatively connected with said hydraulic pressure supply means to provide a power assist therefor, said pneumatic booster assembly including a sealed cavity therein, said cavity divided into a first and a second chamber by a diaphragm piston means, said diaphragm piston being operatively connected with said hydraulic pressure supply means for the actuation thereof, said first chamber being connected with a source of vacuum, a first pneumatic conduit communicating said chamber with said second chamber, and an air change-off valve means connected in said second pneumatic conduit means, said change-off valve having a first position and a second position, said first position for communicating said first chamber of said pneumatic booster with said vacuum source and said second position for communicating ambient atmosphere to said first chamber and connecting said second chamber with said vacuum source, said change-off valve means being actuated by said control means in response to a sensed skid condition by said skid-sensing means, whereby said cut-off valve is actuated and said air change-off valve causes said pneumatic booster to decrease the amount of hydraulic pressure supplied to the brakes of said other wheel pairs by said hydraulic pressure supply means to allow said wheels of said other wheel pair to rotate.

Claim 6

Dependent Claim 164 words

An automotive brake system as claimed in claim 1 further comprising a pressure control valve means, said pressure control valve means connected in said second conduit means, said pressure control valve means including a housing having a stepped bore therein, a stepped piston slidably positioned in said stepped bore, said stepped piston having a smaller diameter portion communicating with said hydraulic pressure supply means and a larger piston portion communicating with the actuating cylinders of said other of said wheel pairs, a conduit communicating said smaller diameter portion of said stepped piston with said larger diameter portion thereof, a valve means located in said interconnecting conduit and operatively connected with said stepped piston, a biasing means for biasing said valve means in an open position, whereby, when hydraulic pressure is applied by said hydraulic pressure supply means, said stepped piston is caused to reciprocate to allow the pressure supplied to the wheel brake assemblies of said other of said wheel pairs to increase step-wise.

Claim 7

Dependent Claim 227 words

An automotive brake system as claimed in claim 1, further comprising a load sensing valve means connected in said second conduit means, said load sensing valve means including a stepped piston slidably positioned in a cylinder said stepped piston having a smaller diameter portion and a larger diameter portion formed thereon, an interconnecting conduit communicating the portion of said cylinder containing said larger diameter portion of said piston with the cylinder portion containing the smaller diameter portion of said piston, said smaller diameter portion of said piston communicating with said hydraulic pressure supply means, a valve means located in said interconnecting passage and operatively connected with said piston assembly to selectively block communication of said smaller diameter piston portion with said larger diameter piston portion, a first biasing means for biasing said valve means in an open position, said load sensing valve means being connected between a load supporting sprung portion and an unsprung portion of a vehicle through a second biasing means, said second biasing means acting in opposition to said first biasing means, whereby, as the vehicle loads increase, said first biasing means moves said valve means towards its open position, thereby allowing reciprocable movement of said stepped piston tO cause the hydraulic pressure applied to the wheel brakes of the other of said wheel pairs to increase step-wise as the vehicle load is increased.

Claim 8

Dependent Claim 93 words

An automotive brake system as claimed in claim 1, said control means comprising a self-holding circuit means including a sloenoid and a switching means, said solenoid being operatively connected with said skid sensing means to hold said switching means in a closed position during operation of said sensing means, said switching means operatively connected with said cut-off valve means to control the actuation thereof, and further including a second switching means for controlling the operation of said solenoid, said second switching means actuated in response to a signal created by said skid means.

Claim 9

Dependent Claim 67 words

An automotive brake system as claimed in claim 1, wherein said skid sensing means comprises, a direct current generator having an armature operatively connected to said other wheel pairs and having the winding of a field yoke connected to said control means for actuating said control means when said generator ceases to generate an electric current when said other wheel pairs are locked in a skid condition.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1975-03-21	1975-09-20	1976-03-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1979-03-21	1979-09-20	1980-03-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1983-03-21	1983-09-20	1984-03-21	$7700.00	Window Closed / Lapsed

Antiskid brake assembly

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