Patent US4075840A successfully refreshed from Google Patents.
US4075840A
Expired / Lapsed
US
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Brake and steering system
Assignee: CLARK MICHIGAN COMPANY CIRCLE DRIVE BUCHMANAN MICHIGAN A CORP OF
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Filing: 1976-10-06
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Granted: 1978-02-28
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Expires: 1996-10-06
Abstract
Abstract A combined brake and steering system for a vehicle having hydraulic braking and hydraulic steering. A single pump is utilized to supply both the brakes and steering. Two priority valves are arranged to assure that the brakes take precedence and receive an approximately constant flow of hydraulic fluid subject to a maximum pressure. The steering mechanism also normally receives a constant flow, subject to a maximum pressure which usually is different from the other maximum pressure.
Inventors
- 👤 Ronald M. Jesswein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:43
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/06; B62D5/07; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/161; B62D12/00; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2514; Y10T137/2521; Y10T137/2524
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
217 words
A combined brake and steering hydraulic system for a vehicle, comprising a hydraulic pump on the vehicle having an output of a predetermined maximum amount of fluid in a normal operating range, a first priority valve having a first inlet and a first regulated outlet and a first by-pass outlet, the said first inlet connected to receive the entire output of the said pump, the said first regulated outlet during normal operation discharging an approximately constant flow of fluid, an open center hydraulic brake mechanism on the vehicle, first conduit means directing fluid from the said first regulated flow outlet to the said brake mechanism, a second priority valve having a second inlet and a second regulated outlet and a second by-pass outlet, second conduit means directing the flow from the said first by-pass outlet to the said second inlet, an open center hydraulic steering mechanism on the vehicle, the said second regulted outlet discharging fluid during some conditions of operation at a second approximately constant flow, means directing the flow from the said second regulated outlet to the said steering mechanism, the total of the said first and second constant flows being less than the said predetermined maximum amount, and the said second by-pass outlet discharging the remainder of the fluid output of the said pump.
Claim 2
Dependent Claim
217 words
A combined brake and steering hydraulic system for a vehicle, comprising a hydraulic pump on the vehicle having an output of a predetermined maximum amount of fluid in a normal operating range, a first priority valve having a first inlet and a first regulated outlet and a first by-pass outlet, the said first inlet connected to receive the entire output of the said pump, the said first regulated outlet during normal operation discharging an approximately constant flow of fluid, an open center hydraulic brake mechanism on the vehicle, first conduit means directing fluid from the said first regulated flow outlet to the said brake mechanism, a second priority valve having a second inlet and a second regulated outlet and a second by-pass outlet, second conduit means directing the flow from the said first by-pass outlet to the said second inlet, an open center hydraulic steering mechanism on the vehicle, the said second regulted outlet discharging fluid during some conditions of operation at a second approximately constant flow, means directing the flow from the said second regulated outlet to the said steering mechanism, the total of the said first and second constant flows being less than the said predetermined maximum amount, and the said second by-pass outlet discharging the remainder of the fluid output of the said pump.
Claim 3
Dependent Claim
30 words
A system as in claim 1 in which the said hydraulic steering mechanism operates at a lower hydraulic pressure than the maximum hydraulic operating pressure of the said brake mechanism.
Claim 4
Dependent Claim
36 words
A system as in claim 1 in which the said hydraulic steering mechanism operates at a higher hydraulic pressure than the maximum hydraulic pressure produced in the system by the operation of the said brake mechanism.
Claim 5
Dependent Claim
54 words
A system as in claim 1 in which a first relif valve is connected to limit the pressure at the said first regulated outlet to a predetermined pressure and a second relief valve is connected to limit the pressure at the said second regulated outlet to an amount lower than the said predetermined pressure.
Claim 6
Dependent Claim
45 words
A system as in claim 1 including a reservoir and in which fluid discharged from said hydraulic brake mechanism, together with the fluid discharged from said hydraulic steering mechanism and the reminder of the fluid output of said pump, all are discharged into said reservoir.
Claim 7
Dependent Claim
28 words
A system as in claim 4 including conduit means connecting said reservoir and the inlet of said hydraulic pump to provide for fluid circulation in a closed system.
Claim 8
Dependent Claim
76 words
A system as in claim 1 in which said pump has an idle condition in which the fluid output of said pump is less than said predetermined maximum amount, and in which the total of said first and second constant flows is less than said predetermined maximum amount, the said first constant flow being maintained during said idle condition while said second regulated outlet discharges less than said second constant flow to said hydraulic steering mechanism.
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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) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |