Patent US3703319A successfully refreshed from Google Patents.
US3703319A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic systems for vehicles
Assignee: Girling Ltd
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Filing: 1970-09-17
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Granted: 1972-11-21
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Expires: 1990-09-17
Abstract
Abstract In a vehicle hydraulic braking system fluid under pressure from a master cylinder is supplied to a wheel brake through a chamber of which the effective volume is variable between a minimum value and a maximum value by movement of a piston assembly working in a bore in communication with the chamber. Means are included for normally subjecting the piston assembly to a supply of pressure fluid to urge the piston assembly into a first position in which the effective volume of the chamber is at the minimum value. A control valve is operative in response to a control signal to cause movement of the piston assembly in a second opposite direction to increase the effective volume of the chamber whereby the pressure of hydraulic fluid applied to the wheel brake is reduced.
Inventors
- 👤 Brian Ingram
- 👤 David Anthony Harries
- 👤 Lancelot Phoenix
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:35
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/343; B60T8/344; B60T8/345; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/141; B60T8/42; B60T8/4208; B60T8/4225; B60T8/4233; Y; Y10; Y10S; Y10S303/00; Y10S303/11
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
241 words
An hydraulic braking system for a vehicle comprising a supply of hydraulic fluid, a wheel brake, a master cylinder for controlling the pressure of hydraulic fluid applied to said wheel brake from said supply, an actuator interposed between said master cylinder and said wheel brake, means in said actuator defining a chamber having an inlet connected to said master cylinder and an outlet connected to said wheel brake, a piston assembly working in a bore in said actuator communicating with said chamber and movable between a first advanced position in which the effective volume of said chamber is at a minimum value and a second retracted position in which the effective volume of said chamber is greater than said minimum value, a movable wall in said actuator and acting on said piston assembly, pressure means for normally subjecting one side of said movable wall to a supply of pressure fluid to urge said piston assembly into said first position, sensing means for providing a control signal when the deceleration of the braked wheel exceeds a predetermined value, and a control valve responsive to said control signal to connect said pressure fluid to the opposite side of the movable wall to equalize the pressure on each side of the movable wall and to cause movement of said piston assembly to said second position whereby the pressure of said hydraulic fluid in a line between said chamber and said wheel brake is reduced.
Claim 2
Dependent Claim
241 words
An hydraulic braking system for a vehicle comprising a supply of hydraulic fluid, a wheel brake, a master cylinder for controlling the pressure of hydraulic fluid applied to said wheel brake from said supply, an actuator interposed between said master cylinder and said wheel brake, means in said actuator defining a chamber having an inlet connected to said master cylinder and an outlet connected to said wheel brake, a piston assembly working in a bore in said actuator communicating with said chamber and movable between a first advanced position in which the effective volume of said chamber is at a minimum value and a second retracted position in which the effective volume of said chamber is greater than said minimum value, a movable wall in said actuator and acting on said piston assembly, pressure means for normally subjecting one side of said movable wall to a supply of pressure fluid to urge said piston assembly into said first position, sensing means for providing a control signal when the deceleration of the braked wheel exceeds a predetermined value, and a control valve responsive to said control signal to connect said pressure fluid to the opposite side of the movable wall to equalize the pressure on each side of the movable wall and to cause movement of said piston assembly to said second position whereby the pressure of said hydraulic fluid in a line between said chamber and said wheel brake is reduced.
Claim 3
Dependent Claim
241 words
An hydraulic braking system for a vehicle comprising a supply of hydraulic fluid, a wheel brake, a master cylinder for controlling the pressure of hydraulic fluid applied to said wheel brake from said supply, an actuator interposed between said master cylinder and said wheel brake, means in said actuator defining a chamber having an inlet connected to said master cylinder and an outlet connected to said wheel brake, a piston assembly working in a bore in said actuator communicating with said chamber and movable between a first advanced position in which the effective volume of said chamber is at a minimum value and a second retracted position in which the effective volume of said chamber is greater than said minimum value, a movable wall in said actuator and acting on said piston assembly, pressure means for normally subjecting one side of said movable wall to a supply of pressure fluid to urge said piston assembly into said first position, sensing means for providing a control signal when the deceleration of the braked wheel exceeds a predetermined value, and a control valve responsive to said control signal to connect said pressure fluid to the opposite side of the movable wall to equalize the pressure on each side of the movable wall and to cause movement of said piston assembly to said second position whereby the pressure of said hydraulic fluid in a line between said chamber and said wheel brake is reduced.
Claim 4
Dependent Claim
241 words
An hydraulic braking system for a vehicle comprising a supply of hydraulic fluid, a wheel brake, a master cylinder for controlling the pressure of hydraulic fluid applied to said wheel brake from said supply, an actuator interposed between said master cylinder and said wheel brake, means in said actuator defining a chamber having an inlet connected to said master cylinder and an outlet connected to said wheel brake, a piston assembly working in a bore in said actuator communicating with said chamber and movable between a first advanced position in which the effective volume of said chamber is at a minimum value and a second retracted position in which the effective volume of said chamber is greater than said minimum value, a movable wall in said actuator and acting on said piston assembly, pressure means for normally subjecting one side of said movable wall to a supply of pressure fluid to urge said piston assembly into said first position, sensing means for providing a control signal when the deceleration of the braked wheel exceeds a predetermined value, and a control valve responsive to said control signal to connect said pressure fluid to the opposite side of the movable wall to equalize the pressure on each side of the movable wall and to cause movement of said piston assembly to said second position whereby the pressure of said hydraulic fluid in a line between said chamber and said wheel brake is reduced.
Claim 5
Dependent Claim
88 words
An hydraulic braking system as claimed in claim 22 incorporating means for restoring said control valve to an inoperative position at the termination of said control signal cutting of said supply of pressure fluid to the opposite side of the movable wall whereby said piston assembly is again urged by said supply of pressure fluid on said one side of the movable wall into said first advanced position to progressively reduce said effective volume of said chamber to said minimum value and effect re-application of said wheel brake.
Claim 6
Dependent Claim
35 words
An hydraulic braking system as claimed in claim 1, wherein said movable wall comprises a piston working in an hydraulic cylinder and subjected over different areas to hydraulic fluid pressures controlled by said control valve.
Claim 7
Dependent Claim
17 words
An hydraulic braking system as claimed in claim 1 wherein the movable wall comprises a diaphragm assembly.
Claim 8
Dependent Claim
73 words
An hydraulic braking system as claimed in claim 1, including a spring acting on said pressure fluid urging said movable wall and said piston assembly towards said first advanced position in which said effective volume of said chamber is at said minimum value whereby, in the event of the failure of said pressure fluid, movement of said piston assembly towards said second retracted position is in opposition to the force in said spring.
Claim 9
Dependent Claim
38 words
An hydraulic braking systEm as claimed in claim 1, wherein valve means under the control of said piston assembly are adapted to control the flow of fluid from said master cylinder to said wheel brake through said chamber.
Claim 10
Dependent Claim
26 words
An hydraulic braking system as claimed in claim 6, wherein said valve means comprises a two stage valve whereby brake application and release is effected gradually.
Claim 11
Dependent Claim
55 words
An hydraulic braking system as claimed in claim 22, including an electrically inductive sensor fitted to said wheel and an electronic control module to receive an A.C. output signal from said sensor and to convert said A.C. signal into a D.C. output, and a solenoid energized by said D.C. output for actuating said control valve.
Claim 12
Dependent Claim
78 words
An hydraulic braking system as claimed in claim 8 wherein each wheel of the vehicle is provided with an electrically inductive sensor, a separate electronic control module for each wheel to receive an A.C. output signal from said sensor and to convert said A.C. signal into a D.C. output, a solenoid energized by said D.C. output to actuate said control valve for controlling delivery to and exhaust from said actuator which regulates said effective volume of said chamber.
Claim 13
Dependent Claim
50 words
An hydraulic braking system as claimed in claim 8, wherein the A.C. output signals from a pair of wheel sensors are fed into a common electronic control module which differentiates the signals and feeds a D.C. output to the solenoid operated valve controlling the braking of that pair of wheels.
Claim 14
Dependent Claim
39 words
An hydraulic braking system as claimed in claim 1 wherein said piston assembly comprises an expander piston for regulating said effective volume of said chamber, and an actuator piston of greater diameter for controlling movement of the expander piston.
Claim 15
Dependent Claim
35 words
An hydraulic braking system as claimed in claim 1, wherein said piston assembly comprises two expander pistons in parallel relationship, and a single actuator piston of large diameter for controlling movement of both expander pistons.
Claim 16
Dependent Claim
17 words
An hydraulic braking system as claimed in claim 12, wherein said expander pistons are equal in diameter.
Claim 17
Dependent Claim
17 words
An hydraulic braking system as claimed in claim 12, wherein said expander pistons are of different diameters.
Claim 18
Dependent Claim
150 words
An hydraulic braking system as claimed in claim 1 wherein said piston assembly comprises at least one expander piston for controlling said effective volume of said chamber, a single actuator piston for controlling movement of said expander piston, said actuator piston at an end remote from said expander piston being provided with a recessed bore, and a third piston working in said bore in said actuator piston, and wherein the space between said third piston and said recessed bore forms an hydraulic accumulator to which said pressure fluid is normally admitted through an axial inlet port in said third piston to hold said expander piston in an advanced position in which said effective volume of said chamber is at said minimum value, and valve means for controlling communication between said chamber and said wheel brakes are held in an open position when said expander piston is in said advanced position.
Claim 19
Dependent Claim
29 words
An hydraulic braking system as claimed in claim 15 including a spring acting on said third piston to urge said third piston towards said actuator piston at all times.
Claim 20
Dependent Claim
86 words
An hydraulic braking system as claimed in claim 1 wherein said control valve comprises a solenoid operated control valve incorporating a valve member, a seating, and a pre-loaded spring normally holding said valve member against said seating to prevent high pressure fluid escaping therefrom, an electronic module for producing a D.C. signal responsive to deceleration of said braked wheel for energizing said solenoid whereafter said valve member is moved away from said seating by the pressure of said fluid against the force in said pre-loaded spring.
Claim 21
Dependent Claim
68 words
An hydraulic braking system as claimed in claim 17 wherein movement of said valve member away from said seating closes an outlet to a reservoir supplying a source for said pressure fluid and said pressure fluid is admitted to a space in said bore in which works said piston assembly whereby said piston assembly is moved in a direction to increase progressively said effective volume of said chamber.
Claim 22
Dependent Claim
126 words
An hydraulic braking system as claimed in claim 18, where said piston assembly and said movable wall include a differential piston working in a stepped bore, and said space in said bore is located between a portion of said differential piston of greater diameter and a step in said stepped bore at the change in diameter, and said pressure fluid is normally supplied to an end of said larger diameter portion over an area less than an area of said piston at the change in diameter to urge said piston assembly into said first advanced position, whereby said fluid admitted to said space at an equal pressure causes a resultant force to be applied to said piston assembly to increase said effective volume of said chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |