US3561573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-adjusting electrohydraulic brake control
Assignee: Westinghouse Electric Corp
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Filing: 1968-12-09
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Granted: 1971-02-09
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Expires: 1988-12-09
Abstract
Abstract A compact electrohydraulic brake control system in which a reservoir of brake fluid is employed to compensate for brake shoe wear and for brake fluid leakage. In addition, an electric recycling circuit provides a means for compensating for fluid leakage, and a check valve arrangement prevents the hydraulic system from becoming air bound even when the fluid containing parts thereof are above the fluid level in the reservoir.
Inventors
- 👤 Laird R Allen Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:18
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/14; F16D65/28; B; B60; B60T; B60T17/00; B60T17/18; B60T17/22; F16D55/00; F16D65/38; F16D65/72; F16D65/74; F16D2121/00; F16D2121/14; F16D2121/18; F16D2121/20; F16D2125/00; F16D2125/02; F16D2125/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
An electrohydraulic brake arrangement comprising: a housing structure; a master cylinder and a slave cylinder each having a piston disposed in respective sliding engagement in said cylinders, said cylinders being connected together in fluid communication to form a hydraulic actuating system; a reservoir of brake fluid connected in fluid communication with said hydraulic actuating system; a control valve operatively associated with said master cylinder for controlling the flow of brake fluid between said hydraulic actuating system and said reservoir; a brake-actuating solenoid and armature disposed in said housing structure, said armature being mechanically connected to operate the master piston; a brake structure including a brake shoe disposed to engage a braking surface associated with a vehicle wheel; a load spring disposed to engage said brake structure and to force said shoe in the direction of said surface; and the slave piston being disposed to engage said brake structure, and to force said brake shoe from said surface against the force of said load spring when said solenoid is energized.
Claim 2
Dependent Claim
169 words
An electrohydraulic brake arrangement comprising: a housing structure; a master cylinder and a slave cylinder each having a piston disposed in respective sliding engagement in said cylinders, said cylinders being connected together in fluid communication to form a hydraulic actuating system; a reservoir of brake fluid connected in fluid communication with said hydraulic actuating system; a control valve operatively associated with said master cylinder for controlling the flow of brake fluid between said hydraulic actuating system and said reservoir; a brake-actuating solenoid and armature disposed in said housing structure, said armature being mechanically connected to operate the master piston; a brake structure including a brake shoe disposed to engage a braking surface associated with a vehicle wheel; a load spring disposed to engage said brake structure and to force said shoe in the direction of said surface; and the slave piston being disposed to engage said brake structure, and to force said brake shoe from said surface against the force of said load spring when said solenoid is energized.
Claim 3
Dependent Claim
38 words
The arrangement described in claim 1 in which the slave cylinder is provided with a takeup spring to maintain the engagement of the slave piston with the brake structure during negative pressure transients in the hydraulic actuating system.
Claim 4
Dependent Claim
47 words
The arrangement described in claim 1 in which the control valve is located in the master piston with an operating means disposed to engage an end wall of the master cylinder, said valve being in a fully open position when the master piston engages said end wall.
Claim 5
Dependent Claim
65 words
The arrangement of claim 1 in which the master and slave cylinders are connected together by conduit means having at least two branches, and an unidirectional valve means connected respectively in each branch, said valves further being connected to allow fluid flow in said branches in one and respectively opposite directions, said valves being further operative to maintain a minimum pressure in the slave cylinder.
Claim 6
Dependent Claim
44 words
The arrangement described in claim 1 in which the armature has a tapered end portion, and the housing structure has a tapered end portion adjacent thereto, said tapered end portions forming an inclined gap through which the armature moves when the solenoid is energized.
References Cited (Backward Citations)
US3077186A
Cited
US3218796A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |