US3798525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro hydraulic steering system
Assignee: SPX Technologies Inc
•
Filing: 1972-05-18
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Granted: 1974-03-19
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Expires: 1992-05-18
Abstract
Abstract An electro-hydraulic system especially adapted for the steering of riverboats and the like according to which accurate control is gained in the steering operation. The system includes a variable volume piston pump under the control of a servo controller so as to produce variable rates of fluid flow from the pump to an output steering device which is operative to effectuate precision steering of the vehicle. A steering device position feedback arrangement is provided according to which a signal is fed back, responsive to movement of the steering device, in such a way as to effectively nullify the initiating signal input to the servo controller, thereby to return the pump to a null position at a time when the steering device has assumed the position desired.
Inventors
- 👤 H Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:12
CPC Classifications
B; B63; B63H; B63H25/00; B63H25/06; B63H25/08; B63H25/14; B63H25/18; B63H25/24; F; F15; F15B; F15B21/00; F15B21/08; F15B21/085
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
134 words
An electro-hydraulic steering system for remotely controlling the movement of a steering device comprising a steering control means for producing an input command signal, a servo motor, a servo controller responsive to the command signal from said steering control means for effecting movement of said motor, a pump coupled to said servo motor and controlled by said motor to produce varied rates of fluid flow, a steering device controlled by fluid flow from said pump so as to reach a predetermined position, and, means, coupled to respond to movement of said steering device, for feeding back a signal to said steering control means so as to null the input command signal to said servo controller and return said pump to a null position, when the predetermined position for said steering device has been reached.
Claim 2
Dependent Claim
134 words
An electro-hydraulic steering system for remotely controlling the movement of a steering device comprising a steering control means for producing an input command signal, a servo motor, a servo controller responsive to the command signal from said steering control means for effecting movement of said motor, a pump coupled to said servo motor and controlled by said motor to produce varied rates of fluid flow, a steering device controlled by fluid flow from said pump so as to reach a predetermined position, and, means, coupled to respond to movement of said steering device, for feeding back a signal to said steering control means so as to null the input command signal to said servo controller and return said pump to a null position, when the predetermined position for said steering device has been reached.
Claim 3
Dependent Claim
21 words
A system as defined in claim 1 in which said steering control means comprises a steering wheel and a first potentiometer.
Claim 4
Dependent Claim
25 words
A system as defined in claim 2 in which said first potentiometer includes a movable contact connected to an input point on said servo controller.
Claim 5
Dependent Claim
39 words
A system as defined in claim 1 in which said feedback means includes means for feeding a signal of a polarity opposite to said input command signal, said feedback means having the same input point as said input signal.
Claim 6
Dependent Claim
23 words
A system as defined in claim 4, said feedback means comprising a second potentiometer including a movable contact connected to said input point.
Claim 7
Dependent Claim
37 words
A system as defined in claim 1, further comprising an hydraulic circuit between said pump and said steering device, and an over-center pump for effecting movement of said steering device in opposite directions from a null position.
Claim 8
Dependent Claim
26 words
A system as defined in claim 1, in which said steering device comprises a cylinder and a piston within said cylinder for actuating a steering element.
Claim 9
Dependent Claim
17 words
A system as defined in claim 7 in which said piston is coupled to said feedback means.
Claim 10
Dependent Claim
24 words
A system as defined in claim 1, further including another feedback means connected between said servo motor and the input to said servo controller.
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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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |