Patent US3563261A successfully refreshed from Google Patents.
US3563261A
Expired / Lapsed
US
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Lockout valve assemblies for hydraulic control systems
Assignee: FW McConnel Ltd
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Filing: 1969-06-11
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Granted: 1971-02-16
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Expires: 1989-06-11
Abstract
Abstract A lockout valve assembly comprises first and second nonreturn valves, arranged to permit flow from a hydraulic control valve to the two sides respectively of a double-acting hydraulic ram. Each nonreturn valve comprises a chamber for communication with a service port of the hydraulic control valve, a movable main valve member engageable with a valve seat surrounding an outlet for communication with one side of the double-acting device, and a pilot valve member engageable with a pilot port in the main valve member, there being provided between the first and second nonreturn valves a reciprocable plunger assembly having one end thereof projecting into each valve chamber and arranged, when moved further into the chamber, to engage and move the pilot valve member in a manner to permit flow of hydraulic fluid through the pilot port. There is movable with each valve member a piston part reciprocable within a bore closed at one end there being a restricted passage through which hydraulic fluid can escape as the piston part moves towards the closed end of the bore and through which fluid must pass to enter the bore and cause closure of the pilot valve.
Inventors
- 👤 Willard Denis Griffith
- 👤 Paul Gerrard Bottrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:53
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/01; F15B13/015; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2544; Y10T137/2708
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
161 words
A lockout valve assembly comprising first and second nonreturn valves, adapted to permit flow from a hydraulic control valve to the two sides respectively of a double-acting device, each nonreturn valve comprising a chamber for communication with a service port of the hydraulic control valve, a movable main valve member engageable with a valve seat surrounding an outlet for communication with one side of the double-acting device, and a pilot valve member engageable with a pilot port in the main valve member, there being provided between the first and second nonreturn valves a reciprocable plunger assembly having one end thereof projecting into each valve chamber and adapted, when moved further into the chamber, to engage and move the pilot valve member in a manner to permit flow of hydraulic fluid through the pilot port, means being provided to restrict the speed of movement of the pilot valve member in the direction to arrest flow of hydraulic fluid through the pilot port.
Claim 2
Dependent Claim
161 words
A lockout valve assembly comprising first and second nonreturn valves, adapted to permit flow from a hydraulic control valve to the two sides respectively of a double-acting device, each nonreturn valve comprising a chamber for communication with a service port of the hydraulic control valve, a movable main valve member engageable with a valve seat surrounding an outlet for communication with one side of the double-acting device, and a pilot valve member engageable with a pilot port in the main valve member, there being provided between the first and second nonreturn valves a reciprocable plunger assembly having one end thereof projecting into each valve chamber and adapted, when moved further into the chamber, to engage and move the pilot valve member in a manner to permit flow of hydraulic fluid through the pilot port, means being provided to restrict the speed of movement of the pilot valve member in the direction to arrest flow of hydraulic fluid through the pilot port.
Claim 3
Dependent Claim
67 words
A lockout valve assembly according to claim 1 wherein there is movable with the valve member a piston part reciprocable within a bore closed at one end there being a restricted passage through which hydraulic fluid can escape as the piston part moves towards the closed end of the bore and through which fluid must pass to enter the bore and cause closure of the pilot valve.
Claim 4
Dependent Claim
36 words
A lockout valve assembly according to claim 2, wherein the restricted passage is in communication with a part of the hydraulic circuit which is on the side of the main valve member nearer the double-acting device.
Claim 5
Dependent Claim
27 words
A lockout valve assembly according to claim 3, wherein the restricted passage is provided by a clearance between the piston part and the walls of the bore.
Claim 6
Dependent Claim
27 words
A lockout valve assembly according to claim 2, wherein there is provided a spring opposing movement of the piston part towards the closed end of the bore.
Claim 7
Dependent Claim
124 words
A lockout valve assembly according to claim 1, wherein the reciprocable plunger assembly comprises a first plunger and a second, longer plunger of smaller cross-sectional area passing through the first Plunger and reciprocable relatively thereto to a limited extent, each said pilot valve member and pilot port being so arranged that movement of the plunger assembly as a whole moves said pilot valve member to an extent to permit a restricted flow of hydraulic fluid through the pilot port, and further movement of the second plunger, relatively to the first plunger, moves said pilot member to a further extent permitting a greater flow of hydraulic fluid through the pilot port sufficient to permit the main valve member to move away from its valve seat.
Claim 8
Dependent Claim
42 words
A lockout valve assembly according to claim 6 wherein the pilot valve member and pilot port are so shaped that movement of the valve member by the plunger assembly causes a gradually increasing restricted flow of hydraulic fluid through the pilot port.
Claim 9
Dependent Claim
49 words
A lockout valve assembly according to claim 7 wherein the pilot port comprises a passage of uniform cross-sectional area in the main valve member, and the pilot valve member comprises a portion movable into and out of the passage, the cross-sectional area of which portion varies along its length.
Claim 10
Dependent Claim
65 words
A lockout valve assembly according to claim 8, wherein said passage is of circular cross section and said portion of the pilot valve member is also of mainly circular cross section so as to be slidable within the passage but which portion has formed on its surface at least one flat plane inclined to the central axis of the portion of the pilot valve member.
Claim 11
Dependent Claim
39 words
A lockout valve assembly according to claim 6, wherein said second plunger is formed with abutments disposed to engage parts of said first plunger so as to limit movement of the second plunger with respect to the first plunger.
Claim 12
Dependent Claim
21 words
A lockout valve assembly according to claim 10, wherein said abutments comprise enlarged heads at opposite ends of the second plunger.
Claim 13
Dependent Claim
20 words
A lockout valve assembly according to claim 6, wherein each plunger is formed in two abutting but otherwise unconnected parts.
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) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |