Patent US3798525A successfully refreshed from Google Patents.
US3798525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro hydraulic steering system
Assignee: SPX Technologies Inc
•
Filing: 1972-05-18
•
Granted: 1974-03-19
•
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 13:59
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.
References Cited (Backward Citations)
US3106084A
Cited
US2964059A
Cited
US3418547A
Cited
US3269676A
Cited
US3405676A
Cited
US3390614A
Cited
US3527186A
Cited
US3570243A
Cited
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 |