Patent US3916946A successfully refreshed from Google Patents.
US3916946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety check valve for pressure fluid operated apparatus in particular presses
Assignee: Herion Werke KG
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Filing: 1973-11-16
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Granted: 1975-11-04
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Expires: 1993-11-16
Abstract
Abstract A safety check valve for pressure operated apparatus, in particular presses comprises two axially disposed control pistons movable axially independently of one another in a cylindrical housing having a fluid inlet at one end and an outlet at the other. One of the control pistons has a closed end engageable with a first valve seat surrounding the inlet opening of the housing, an axial bore surrounded by a second valve seat at the opposite end of the piston and at least one radial hole communicating with the axial bore. The other control piston has a closed end engageable with the second valve seat, an axial bore opening at the opposite end of the piston and at least one radial hole. The control pistons are spring biased toward their respective valve seats and are movable against the bias by fluid pressure. With this arrangement either control piston will check the return flow of fluid regardless of the position of the other.
Inventors
- 👤 Helmut Motzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:33
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/02; F16K17/04; F16K17/044; F16K15/00; F16K15/02; F16K15/06; F16K15/063; F16K15/066; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7838; Y10T137/7841; Y10T137/7876; Y10T137/7904; Y10T137/7922; Y10T137/7925; Y10T137/8158; Y10T137/8225; Y10T137/8242
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
318 words
A safety check valve for controlling flow of pressure fluid in a supply line for pressure fluid operated apparatus, in particular presses, comprising a cylindrical housing with an axial bore, an inlet opening at one end of said bore and an outlet opening at the opposite end of said bore, said bore providing a fluid passageway through the housing between said inlet opening and said outlet opening, first and second control pistons disposed in tandem in said bore between said inlet opening and said outlet opening, each of said control pistons having at the end thereof nearest said inlet opening a valve portion with a working face, a first annular valve seat surrounding said inlet opening and engageable by the working face of the valve portion of said first control piston to close said passageway, a second annular valve seat located between said inlet opening and said outlet opening and engageable by the working face of the valve portion of said second control piston to close said passageway, means biasing the first and second control pistons toward their respective valve seats to close the valve, said pistons being movable by line pressure applied through said inlet opening and acting on said working faces of said valve portions in a direction against the bias of said biasing means to open said valve and being urged against said valve seats by line pressure applied in the reverse direction throuGh said outlet opening to close said valve and thereby prevent flow of line fluid in said reverse direction, said control pistons having control surfaces isolated from said passageway and from line pressure, and controllable means for exerting fluid pressure on said control surfaces to move said control pistons against line pressure applied through said outlet opening and against the bias of said biasing means to open the valve and thereby permit controlled flow of said line fluid in said reverse direction.
Claim 2
Dependent Claim
318 words
A safety check valve for controlling flow of pressure fluid in a supply line for pressure fluid operated apparatus, in particular presses, comprising a cylindrical housing with an axial bore, an inlet opening at one end of said bore and an outlet opening at the opposite end of said bore, said bore providing a fluid passageway through the housing between said inlet opening and said outlet opening, first and second control pistons disposed in tandem in said bore between said inlet opening and said outlet opening, each of said control pistons having at the end thereof nearest said inlet opening a valve portion with a working face, a first annular valve seat surrounding said inlet opening and engageable by the working face of the valve portion of said first control piston to close said passageway, a second annular valve seat located between said inlet opening and said outlet opening and engageable by the working face of the valve portion of said second control piston to close said passageway, means biasing the first and second control pistons toward their respective valve seats to close the valve, said pistons being movable by line pressure applied through said inlet opening and acting on said working faces of said valve portions in a direction against the bias of said biasing means to open said valve and being urged against said valve seats by line pressure applied in the reverse direction throuGh said outlet opening to close said valve and thereby prevent flow of line fluid in said reverse direction, said control pistons having control surfaces isolated from said passageway and from line pressure, and controllable means for exerting fluid pressure on said control surfaces to move said control pistons against line pressure applied through said outlet opening and against the bias of said biasing means to open the valve and thereby permit controlled flow of said line fluid in said reverse direction.
Claim 3
Dependent Claim
50 words
A safety check valve according to claim 1, in which each of said control pistons has a central bore closed at the end of said control piston engageable with said respective valve seat and open at the other end and at least one radial opening communicating with said central bore.
Claim 4
Dependent Claim
37 words
A check valve according to claim 2, in which said second valve seat is provided on the end of said first control piston opposite said closed end thereof and surrounds the bore in said first control piston.
Claim 5
Dependent Claim
36 words
A safety check valve according to claim 1, in which said biasing means comprises spring means acting between said housing and the respective control pistons to individually bias said control pistons toward the respective valve seats.
Claim 6
Dependent Claim
25 words
A safety check valve according to claim 1, in which said control surfaces are of greater area than the working faces of said valve portions.
Claim 7
Dependent Claim
40 words
A safety check valve according to claim 1, in which each of said control pistons has intermediate its ends an annular collar having one axial face against which said biasing means presses and an opposite face constituting said control surface.
Claim 8
Dependent Claim
33 words
A safety check valve according to claim 1, comprising electric switch means actuable by one of said control pistons to provide an electric signal upon faulty operation of either of said control pistons.
Claim 9
Dependent Claim
161 words
A check valve according to claim 1, in which each of said control pistons has a central bore closed at one end by said valve portion of the respective piston and open at the opposite end, an annular peripheral surface spaced from said valve portion and in sliding engagement with said axial bore of the housing and at least one radial opening communicating with said central bore and located between said valve portion and said annular peripheral surface, said second valve seat on which the working face of the valve portion of said second control piston seats being on the end of said first control piston opposite said valve portion thereof and surrounding said opposite open end of said central bore of said first control piston, whereby each of said control piston is operable to check flow of fluid in a direction from said outlet opening to said inlet opening independently of the position of the other of said control pistons.
Claim 10
Dependent Claim
39 words
A safety check valve according to claim 8, in which said biasing means comprises spring means acting between said housing and the respective control pistons individually to bias said control pistons in a direction toward said first valve seat.
Claim 11
Dependent Claim
53 words
A safety check valve according to claim 8, comprising electric switch means actuatable by said second control piston when in any position other than the position nearest to said first valve seat to provide an electric signal when either control piston is in a position other than a position to close said passageway.
Claim 12
Dependent Claim
67 words
A check valve according to claim 1, in which said housing comprises an annular control chamber surrounding each of said control pistons and isolated from said passageway, and in which each of said control surfaces is an annular surface on the respective piston defining a wall of the respective control chamber surrounding said piston, said controllable means comprising means for supplying pressure fluid to said control chambers.
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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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |