US3677002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Subsidiary supply for hydraulic brake booster
Assignee: Bendix Corp
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Filing: 1971-02-04
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Granted: 1972-07-18
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Expires: 1991-02-04
Abstract
Abstract A vehicle brake applying mechanism which utilizes a dual source of fluid under pressure to assist the vehicle operator in slowing or stopping the vehicle. The mechanism includes a hydraulic brake booster comprising an operator controlled piston slidably located in a housing for movement at the will of the operator, through the manipulation of valve means to thereby establish a braking force in a master cylinder to which the piston is connected. Under normal conditions the brake booster receives its main source of fluid under pressure from an engine-driven pump which also supplies fluid to the vehicle''s steering gear. However, an independent subsidiary source of fluid under pressure is supplied to the booster should the main source of fluid reach a predetermined minimum value. The subsidiary source is activated or rendered effective by a low flow sensitive switch located in the main supply for energizing an electric pump which is in communication with the booster piston via the valve means. The subsidiary source also actuates a shut-off valve interposed between the booster and steering gear to disestablish flow to the gear, thus conserving the subsidiary source for booster use only.
Inventors
- 👤 Keith H Fulmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:08
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/168
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
133 words
In a vehicle hydraulic system: a hydraulic boost mechanism and a hydraulic device; said boost mechanism including a housing forming a bore in which piston means is slidably received; a first hydraulic source in fluid communication with said device via said bore; a second hydraulic source normally ineffective and in fluid communication with said bore; operator-operated valve means for controlling the application of said first and second hydraulic sources to said piston means to cause it to reciprocate in said bore; means responsive to a predetermined minimum flow through said first source for effectuating said second source; second valve means within said housing responsive to the effectuation of said second source for interrupting communication between said device and said bore, to thereby conserve the second source solely for actuation of said boost mechanism.
Claim 2
Dependent Claim
133 words
In a vehicle hydraulic system: a hydraulic boost mechanism and a hydraulic device; said boost mechanism including a housing forming a bore in which piston means is slidably received; a first hydraulic source in fluid communication with said device via said bore; a second hydraulic source normally ineffective and in fluid communication with said bore; operator-operated valve means for controlling the application of said first and second hydraulic sources to said piston means to cause it to reciprocate in said bore; means responsive to a predetermined minimum flow through said first source for effectuating said second source; second valve means within said housing responsive to the effectuation of said second source for interrupting communication between said device and said bore, to thereby conserve the second source solely for actuation of said boost mechanism.
Claim 3
Dependent Claim
26 words
The combination, as recited in claim 1, wherein said hydraulic device is a steering gear connected hydraulically in series flow relationship to said hydraulic boost mechanism.
Claim 4
Dependent Claim
34 words
In a vehicle hydraulic system, as defined in claim 1, wherein said first hydraulic source is a pump driven From the engine of the vehicle, and the second hydraulic source is an electric pump.
Claim 5
Dependent Claim
52 words
In a vehicle hydraulic system, as defined in claim 1, wherein said operator-operated valve means comprises an open-center valve which permits free flow of fluid from said engine driven pump through said boost mechanism from the inlet port to the working port, thence to the steering gear, and back to the pump.
Claim 6
Dependent Claim
39 words
The combination, as defined in claim 4, wherein a fluid shunt is connected from said working port to said inlet port to by-pass fluid away from said working port and return it to said inlet port to be recirculated.
Claim 7
Dependent Claim
24 words
In a vehicle hydraulic system, as defined in claim 4, characterized in that said operator-operated valve means is located concentrically within said piston means.
Claim 8
Dependent Claim
66 words
The invention of claim 1: conduit means communicating said bore with said device; second valve means within said conduit means for controlling fluid communication therethrough; and means communicating said second valve means with said second hydraulic source, said second valve means shifting to a position blocking flow of fluid through said conduit means when fluid from said second source is communicated to said second valve means.
Claim 9
Dependent Claim
185 words
In a hydraulic boost mechanism: a housing provided with a bore; piston means reciprocable in said bore and dividing said bore into two chambers, located at the respective ends of said piston means; two inlet ports, two outlet ports and a working port in communication with said bore; one of said inlet ports, one of said outlet ports and said working port are connectible to a main fluid source; the other of said inlet ports and the other of said outlet ports are connectible to a subsidiary fluid source; operator-operated valve means slidably positioned within said piston means for controlling fluid flow between said ports and said chambers; means responsive to a predetermined minimum fluid flow through said working port for establishing fluid flow at the other of said inlet ports; and means in said housing responsive to fluid under pressure at the other of said inlet ports for interrupting fluid flow from said working port; said last-named means including a slide valve which is closed by the fluid pressure at the other of said inlet ports and opened under the influence of a spring.
Claim 10
Dependent Claim
185 words
In a hydraulic boost mechanism: a housing provided with a bore; piston means reciprocable in said bore and dividing said bore into two chambers, located at the respective ends of said piston means; two inlet ports, two outlet ports and a working port in communication with said bore; one of said inlet ports, one of said outlet ports and said working port are connectible to a main fluid source; the other of said inlet ports and the other of said outlet ports are connectible to a subsidiary fluid source; operator-operated valve means slidably positioned within said piston means for controlling fluid flow between said ports and said chambers; means responsive to a predetermined minimum fluid flow through said working port for establishing fluid flow at the other of said inlet ports; and means in said housing responsive to fluid under pressure at the other of said inlet ports for interrupting fluid flow from said working port; said last-named means including a slide valve which is closed by the fluid pressure at the other of said inlet ports and opened under the influence of a spring.
Claim 11
Dependent Claim
41 words
The hydraulic boost, as defined in claim 8, wherein said valve means includes an open-center valve which permits free flow of fluid between said one of said inlet ports and said working port during an unapplied condition of the boost mechanism.
Claim 12
Dependent Claim
37 words
The hydraulic boost, as defined in claim 8, wherein said flow responsive means comprises a flow sensitive device operatively connected to an electric pump which is in fluid pressure communication with the other of said inlet ports.
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) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |