Patent US3958838A successfully refreshed from Google Patents.
US3958838A
Expired / Lapsed
US
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Brake pressure limiting apparatus for a dual-circuit vehicle brake system
Assignee: Volkswagen AG
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Filing: 1975-01-27
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Granted: 1976-05-25
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Expires: 1995-01-27
Abstract
Abstract A brake pressure limiting device is disclosed for use in a dual-circuit vehicle brake system. The device comprises two valve bodies arranged on a common axis. Each valve body has one inlet for connection with a master brake cylinder and at least one brake line outlet. The pressure at the outlet can be isolated from that at the inlet by a valve element which is axially movable within the valve body between an open and a closed position. Movement of both valve elements in the two valve bodies is controlled by a common actuating member which causes the valve elements to close when the pressures at the valve body inlets exceed a limiting value that is a function of the vehicle load.
Inventors
- 👤 Manfred Totschnig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:09
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/26; B60T11/00; B60T11/10; B60T11/28; B60T11/34
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
250 words
Brake pressure limiting apparatus for a dual-circuit vehicle brake system comprising, in combination: a. a first and a second valve body arranged on a common axis; b. the first valve body having a first inlet adapted for connection with a master cylinder and at least one first outlet for supplying braking pressure in said brake system; c. the second valve body having a second inlet adapted for connection with a master cylinder and at least one second outlet for supplying braking pressure in said brake system; d. a first valve element arranged within said first valve body, said first valve element being movable along said common axis between an open position, in which the pressure at said first inlet is transmitted to said first outlet, and a closed position isolating the pressures at said first inlet and first outlet; e. a second valve element arranged within said second valve body, said second valve element being movable along said common axis between an open position, in which the pressure at said second inlet is transmitted to said second outlet, and a closed position isolating the pressures at said second inlet and second outlet; and f. common actuating means, arranged between said first and second valve bodies, for simultaneously and equally applying an actuating force to said first and second valve element causing said first and second valve element to close when the pressure at said first and second inlets, respectively, exceeds a limiting value that is dependent upon the vehicle load.
Claim 2
Dependent Claim
250 words
Brake pressure limiting apparatus for a dual-circuit vehicle brake system comprising, in combination: a. a first and a second valve body arranged on a common axis; b. the first valve body having a first inlet adapted for connection with a master cylinder and at least one first outlet for supplying braking pressure in said brake system; c. the second valve body having a second inlet adapted for connection with a master cylinder and at least one second outlet for supplying braking pressure in said brake system; d. a first valve element arranged within said first valve body, said first valve element being movable along said common axis between an open position, in which the pressure at said first inlet is transmitted to said first outlet, and a closed position isolating the pressures at said first inlet and first outlet; e. a second valve element arranged within said second valve body, said second valve element being movable along said common axis between an open position, in which the pressure at said second inlet is transmitted to said second outlet, and a closed position isolating the pressures at said second inlet and second outlet; and f. common actuating means, arranged between said first and second valve bodies, for simultaneously and equally applying an actuating force to said first and second valve element causing said first and second valve element to close when the pressure at said first and second inlets, respectively, exceeds a limiting value that is dependent upon the vehicle load.
Claim 3
Dependent Claim
92 words
The brake pressure limiting apparatus defined in claim 1, wherein said common actuating means includes: 1. a pressure chamber having a third inlet adapted for connection with a vehicle load-dependent source of pressure; 2. first axially displaceable piston means, arranged between said chamber and said first valve element, for moving said first valve element in dependence upon the pressure within said chamber; and 3. second axially displaceable piston means, arranged between said chamber and said second valve element, for moving said second valve element in dependence upon the pressure within said chamber.
Claim 4
Dependent Claim
32 words
The brake pressure limiting apparatus defined in claim 2, wherein said common actuating means further includes pretensioned spring means, arranged in said chamber, for pushing apart said first and second piston means.
Claim 5
Dependent Claim
49 words
The brake pressure limiting apparatus defined in claim 3, wherein said common actuating means further includes a first and a second intermediate member arranged between said spring means and said first and said second piston means, respectively, said first and second intermediate members being axially displaceable within said chamber.
Claim 6
Dependent Claim
52 words
The brake pressure limiting apparatus defined in claim 4, wherein said first and said second intermediate members have rigid stop means on their sides facing away from said first and said second piston means, respectively, for limiting the movement of said intermediate members in the directions tending to tension said spring means.
Claim 7
Dependent Claim
202 words
A vehicle brake system comprising, in combination: a. the brake pressure limiting apparatus defined in claim 2, said at least one first outlet including two first outlets and said at least one second outlet including two second outlets; b. a brake pressure reducing, load-dependent brake force distributor comprising two chambers, each chamber having an inlet and an outlet; c. a first front wheel brake connected to one of said first outlets of said brake pressure limiting apparatus and a second front wheel brake connected to one of said second outlets of said brake pressure limiting apparatus; d. a first rear wheel brake connected to one chamber outlet of said brake force distributor and a second rear wheel brake connected to the other chamber outlet of said brake force distributor; e. means connecting said third inlet of said brake pressure limiting apparatus with one of said chamber outlets of said brake force distributor; f. means connecting the other of said first outlets of said brake pressure limiting apparatus with one chamber inlet of said brake force distributor; and g. means connecting the other of said second outlets of said brake pressure limiting apparatus with the other chamber inlet of said brake force distributor.
Claim 8
Dependent Claim
144 words
A vehicle brake system comprising, in combination: a. the brake pressure limiting apparatus defined in claim 2, having one first outlet and one second outlet; b. a brake pressure limiting, load-dependent brake force distributor comprising two chambers, each chamber having an inlet, adapted for connection to a master brake cylinder, and an outlet; c. a first front wheel brake connected to said first outlet of said brake pressure limiting apparatus and a second front wheel brake connected to said second outlet of said brake pressure limiting apparatus; d. a first rear wheel brake connected to one chamber outlet of said brake force distributor, and a second rear wheel brake connected to the other chamber outlet of said brake force distributor; and e. means connecting said third inlet of said brake pressure limiting apparatus with one of said chamber outlets of said brake force distributor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |