Patent US4145956A successfully refreshed from Google Patents.
US4145956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pilot operated stepping valve
Assignee: United States Department of the Air Force
•
Filing: 1977-04-25
•
Granted: 1979-03-27
•
Expires: 1997-04-25
Abstract
Abstract A pilot operated stepping valve where an electrical pulse motor drives a pilot valve spool which controls the flow of hydraulic fluid driving a main valve spool which actuates a hydraulic motor or actuator. The main valve spool follows the pilot spool and is hence sensitive to the pulses received by the pulse motor.
Inventors
- 👤 Edwin W. Rumrill, Jr.
- 👤 Frank D. Lewis, Sr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:34
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/86614
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
171 words
An electrically actuated, hydraulically powered pilot operated stepping valve for hydraulic motors comprising: a valve housing, having an outer surface adapted to be connected between an electrical pulse source and a hydraulic motor and an inner cylindrical surface including a plurality or ports therein; an electrical pulse motor connected at one end of the housing, a hydraulic motor connected at the other end of the housing, a pilot valve spindle rotatably mounted in the housing and connected to the electrical pulse motor, for directing the flow of hydraulic fluid; a main spindle means positioned along an axis common with the said pilot valve spindle adapted to be slidably movable within the cylindrical inner surface of the valve housing; means for channelling and directing hydraulic fluid in response to movement of the pilot valve spindle toward and away from the main spindle means, and a planetary gear system connected between the hydraulic motor and main spindle whereby the maximum capacity of the hydraulic motor is achieved with reduced electrical pulsed motor speed.
Claim 2
Dependent Claim
171 words
An electrically actuated, hydraulically powered pilot operated stepping valve for hydraulic motors comprising: a valve housing, having an outer surface adapted to be connected between an electrical pulse source and a hydraulic motor and an inner cylindrical surface including a plurality or ports therein; an electrical pulse motor connected at one end of the housing, a hydraulic motor connected at the other end of the housing, a pilot valve spindle rotatably mounted in the housing and connected to the electrical pulse motor, for directing the flow of hydraulic fluid; a main spindle means positioned along an axis common with the said pilot valve spindle adapted to be slidably movable within the cylindrical inner surface of the valve housing; means for channelling and directing hydraulic fluid in response to movement of the pilot valve spindle toward and away from the main spindle means, and a planetary gear system connected between the hydraulic motor and main spindle whereby the maximum capacity of the hydraulic motor is achieved with reduced electrical pulsed motor speed.
Claim 3
Dependent Claim
25 words
A pilot operated stepping valve according to claim 1 wherein the means for connecting the motor means and pilot spindle means is a threaded nut.
References Cited (Backward Citations)
US3125002A
Cited
US2654347A
Cited
US3079899A
Cited
US3310284A
Cited
US3709257A
Cited
US3891145A
Cited
US3805670A
Cited
US3875849A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-26 | 1982-09-25 | 1983-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-26 | 1986-09-25 | 1987-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-26 | 1990-09-25 | 1991-03-27 | $7700.00 | Window Closed / Lapsed |