US3774976A — Anti-skid control means for liquid pressure braki…

Claim 1

Independent Claim 357 words

Anti-skid control means for liquid pressure braking system of a vehicle of the kind in which liquid pressure derived from a source at which such pressure is constantly available when the vehicle is in operation, is applied by the operation of a valve under the control of the vehicle driver to motor cylinders acting to apply brakes to wheels of the vehicle, sensing means responsive to conditions preliminary to skidding of the vehicle wheels being provided to control the actual pressure acting in the motor cylinders in such a way that the said actual pressure is reduced automatically when a tendency to skid is sensed and is restored automatically to a value determined by the drivercontrolled valve when the tendency to skid ceases, and in which there are provided, between the driver-controlled valve and at least some of said motor cylindeRs, a shut-off valve closable to prevent flow of liquid from the source of pressure to said motor cylinders and, between said shut-off valve and the motor cylinders, a first chamber in which is movable a plunger operative to vary the volume of said chamber, said shut-off valve being urged towards the closed position and said plunger being urged in a direction to maximise the volume of said chamber by liquid pressure in the braking system and said shut-off valve and plunger being normally held against movement by said liquid pressure in the braking system by the opposing action of a spring and of fluid pressure from the pressure source acting on a movable wall, wherein the fluid pressure providing the said opposing action is produced by fluid in a second chamber which is normally connected to the pressure source and is connected to a low pressure reservoir by operation of the skid sensing means, there being provided, for the passage of liquid between said second chamber and said pressure source and drain, a flowrestricting device and means to provide for flow of liquid in the outward direction from said second chamber, at a rate not controlled by said flow restricting device, comprising a passage in parallel with said flow-restricting device and controlled by a one-way valve.

Claim 2

Dependent Claim 357 words

Anti-skid control means for liquid pressure braking system of a vehicle of the kind in which liquid pressure derived from a source at which such pressure is constantly available when the vehicle is in operation, is applied by the operation of a valve under the control of the vehicle driver to motor cylinders acting to apply brakes to wheels of the vehicle, sensing means responsive to conditions preliminary to skidding of the vehicle wheels being provided to control the actual pressure acting in the motor cylinders in such a way that the said actual pressure is reduced automatically when a tendency to skid is sensed and is restored automatically to a value determined by the drivercontrolled valve when the tendency to skid ceases, and in which there are provided, between the driver-controlled valve and at least some of said motor cylindeRs, a shut-off valve closable to prevent flow of liquid from the source of pressure to said motor cylinders and, between said shut-off valve and the motor cylinders, a first chamber in which is movable a plunger operative to vary the volume of said chamber, said shut-off valve being urged towards the closed position and said plunger being urged in a direction to maximise the volume of said chamber by liquid pressure in the braking system and said shut-off valve and plunger being normally held against movement by said liquid pressure in the braking system by the opposing action of a spring and of fluid pressure from the pressure source acting on a movable wall, wherein the fluid pressure providing the said opposing action is produced by fluid in a second chamber which is normally connected to the pressure source and is connected to a low pressure reservoir by operation of the skid sensing means, there being provided, for the passage of liquid between said second chamber and said pressure source and drain, a flowrestricting device and means to provide for flow of liquid in the outward direction from said second chamber, at a rate not controlled by said flow restricting device, comprising a passage in parallel with said flow-restricting device and controlled by a one-way valve.

Claim 3

Dependent Claim 337 words

Anti-skid control means for a liquid pressure braking system of a vehicle of the kind in which liquid pressure derived from a source at which such pressure is constantly available when the vehicle is in operation, is applied by the operation of a valve under the control of the vehicle driver to motor cylinders acting to apply brakes to wheels of the vehicle, sensing means responsive to conditions preliminary to skidding of the vehicle wheels being provided to control the actual pressure acting in the motor cylinders in such a way that the said actual pressure is reduced automatically when a tendency to skid is sensed and is restored automatically to a value determined by the driver-controlled valve when the tendency to skid ceases, and in which there are provided, between the driver-controlled valve and at least some of said motor cylinders, a shut-off valve closable to prevent flow of liquid from the source of pressure to said motor cylinders and, between said shut-off valve and the motor cylinders, a first chamber in which is movable a plunger operative to vary the volume of said chamber, said shut-off valve being urged towards the closed piston and said plunger being urged in a direction to maximise the volume of said chamber by liquid pressure in the braking system and said shut-off valve and plunger being normally held against movement by said liquid pressure in the braking system by the opposing action of a spring and of fluid pressure from the pressure source acting on a movable wall, wherein the fluid pressure providing the said opposing action is produced by fluid in a second chamber which is normally connected to the pressure source and is connected to a low pressure reservoir by operation of the skid sensing means, there being provided, for the passage of liquid between said second chamber and said pressure source and drain, a flow-control device at least partially preventing flow of liquid into said second chamber while providing substantially free flow out of said chamber.

Claim 4

Dependent Claim 337 words

Anti-skid control means for a liquid pressure braking system of a vehicle of the kind in which liquid pressure derived from a source at which such pressure is constantly available when the vehicle is in operation, is applied by the operation of a valve under the control of the vehicle driver to motor cylinders acting to apply brakes to wheels of the vehicle, sensing means responsive to conditions preliminary to skidding of the vehicle wheels being provided to control the actual pressure acting in the motor cylinders in such a way that the said actual pressure is reduced automatically when a tendency to skid is sensed and is restored automatically to a value determined by the driver-controlled valve when the tendency to skid ceases, and in which there are provided, between the driver-controlled valve and at least some of said motor cylinders, a shut-off valve closable to prevent flow of liquid from the source of pressure to said motor cylinders and, between said shut-off valve and the motor cylinders, a first chamber in which is movable a plunger operative to vary the volume of said chamber, said shut-off valve being urged towards the closed piston and said plunger being urged in a direction to maximise the volume of said chamber by liquid pressure in the braking system and said shut-off valve and plunger being normally held against movement by said liquid pressure in the braking system by the opposing action of a spring and of fluid pressure from the pressure source acting on a movable wall, wherein the fluid pressure providing the said opposing action is produced by fluid in a second chamber which is normally connected to the pressure source and is connected to a low pressure reservoir by operation of the skid sensing means, there being provided, for the passage of liquid between said second chamber and said pressure source and drain, a flow-control device at least partially preventing flow of liquid into said second chamber while providing substantially free flow out of said chamber.

Claim 5

Dependent Claim 40 words

Anti-skid control means according to claim 1, wherein the said means to provide for flow of liquid not controlled by said flow-restricting means comprise means for increasing the effective area of the liquid flow path through the flow restricting means.

Claim 6

Dependent Claim 36 words

Anti-skid control means according to claim 1, wherein variable flow restricting means are provided in series with the one-way valve to provide varying restriction of flow through said passage as liquid escapes from said second chamber.

Claim 7

Dependent Claim 26 words

Anti-skid control means according to claim 4, wherein the flow restricting device provides a degree of flow restriction which varies with the position of the plunger.

Claim 8

Dependent Claim 55 words

Anti-skid control means according to claim 5, wherein the flow restricting device leads from the second chamber into a third chamber on the opposite side of the movable wall to said second chamber, the connections of said second chamber to the pressure source and to the low pressure reservoir being provided through said third chamber.

Claim 9

Dependent Claim 33 words

Anti-skid control means according to claim 6, wherein a valve controlled by the skid-sensing device is provided to connect said second chamber alternatively to said pressure source and to said low pressure reservoir.

Claim 10

Dependent Claim 38 words

Anti-skid control means according to claim 6, wherein the third chamber is connected to the source of pressure through flow restricting means and is connectable to the low pressure reservoir through a valve controlled by the skid-sensing device.

Claim 11

Dependent Claim 38 words

Anti-skid control means according to claim 4, wherein the flow restricting means in series with the one-way valve provide a degree of restriction varying with the position of the movable wall in a cylinder defining said second chamber.

Claim 12

Dependent Claim 32 words

Anti-skid control means according to Claim 4, wherein the flow restricting means in series with the one way valve provide a degree of restriction varying with the pressure in said second chamber.

Claim 13

Dependent Claim 49 words

Anti-skid control means according to Claim 6, wherein the movable wall is a main piston fixed to the plunger movable to vary the volume of the first chamber, and a floating piston mounted in said second chamber and normally spaced from the main piston has an orifice formed therein.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-11-26	1977-05-28	1977-11-27	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-11-26	1981-05-28	1981-11-27	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-11-26	1985-05-28	1985-11-27	$7700.00	Window Closed / Lapsed

Anti-skid control means for liquid pressure braking systems

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag