US3833200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double acting snap action fluidic switch
Assignee: Bendix Corp
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Filing: 1973-05-21
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Granted: 1974-09-03
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Expires: 1993-05-21
Abstract
Abstract A two position fluid pressure responsive piston has a first effective area exposed to a reference fluid pressure, a larger second effective area exposed to a control fluid pressure, and an intermediate effective area exposed to a pressurized supply fluid from which the control fluid pressure is derived. The control fluid pressure is generated in a fluid passage connecting the pressurized supply fluid with the relatively lower reference fluid pressure and provided with first, second and third series flow restrictions and a variable area valve downstream therefrom and in series flow relationship therewith. A first passage is arranged in parallel with the second and third restrictions and a second passage is arranged in parallel with the third restriction. The control fluid pressure varies in response to opening of the variable area valve causing movement of the piston which, in turn, registers with the first and second passages to sequentially block the same causing a corresponding reduction in the control fluid pressure and a snap action of the piston to one of its two positions. Reverse movement of the piston with a hysteresis effect occurs in response to closing movement of the variable area valve which results in movement of the piston and subsequent opening of the second and first passages to cause snap action of the piston to the other of its two positions.
Inventors
- 👤 Combs H Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:06
CPC Classifications
F; F16; F16K; F16K31/00; F16K31/12; F16K31/36; F16K31/38; F16K31/383
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
238 words
Fluid pressure responsive control apparatus comprising: a supply source of pressurized fluid; a drain source of pressurized fluid; conduit meanS connecting said supply source and drain source including first, second and third flow restrictions in series flow relationship and a variable area valve downstream therefrom and in series flow therewith for generating a control fluid pressure which varies in response to the position of said variable area valve; first flow passage means in series flow with said first restriction and parallel flow with said second and third restrictions; second flow passage means in series flow with said first and second restrictions and parallel flow with said third restriction; fluid pressure differential responsive means responsive to said control fluid pressure and said supply fluid pressure and operatively connected to said first and second flow passage means for controlling fluid flow therethrough depending upon the position of said pressure differential responsive means in response to a predetermined differential between said control and supply pressures; said pressure differential responsive means being actuated to a first position in response to a first position of said variable area valve whereby said first and second flow passage means are opened; said pressure differential responsive means being actuated to a second position in response to a second position of said variable area valve whereby said first and second flow passage means are blocked; and signal producing means operatively connected to said pressure differential responsive means.
Claim 2
Dependent Claim
238 words
Fluid pressure responsive control apparatus comprising: a supply source of pressurized fluid; a drain source of pressurized fluid; conduit meanS connecting said supply source and drain source including first, second and third flow restrictions in series flow relationship and a variable area valve downstream therefrom and in series flow therewith for generating a control fluid pressure which varies in response to the position of said variable area valve; first flow passage means in series flow with said first restriction and parallel flow with said second and third restrictions; second flow passage means in series flow with said first and second restrictions and parallel flow with said third restriction; fluid pressure differential responsive means responsive to said control fluid pressure and said supply fluid pressure and operatively connected to said first and second flow passage means for controlling fluid flow therethrough depending upon the position of said pressure differential responsive means in response to a predetermined differential between said control and supply pressures; said pressure differential responsive means being actuated to a first position in response to a first position of said variable area valve whereby said first and second flow passage means are opened; said pressure differential responsive means being actuated to a second position in response to a second position of said variable area valve whereby said first and second flow passage means are blocked; and signal producing means operatively connected to said pressure differential responsive means.
Claim 3
Dependent Claim
51 words
Fluid pressure responsive control apparatus as claimed in claim 1 wherein: said pressure differential responsive means is a piston provided with opposite faces exposed to said control fluid pressure and supply pressure and adapted to slidably traverse said first and second flow passage means to vary the flow therethrough in sequence.
Claim 4
Dependent Claim
84 words
Fluid pressure responsive control apparatus as claimed in claim 2 and further including: a first casing having a portion of said conduit means including said first, second and third restrictions contained therein; a chamber in said casing slidably containing said piston; a second casing having a spaced-apart relationship relative to said first casing and a portion of said conduit means including said variable area valve contained therein; and fluid passage means defining a portion of said conduit means interconnecting said first and second casings.
Claim 5
Dependent Claim
22 words
Fluid pressure responsive control apparatus as claimed in claim 1 wherein: said first, second and third flow restrictions have fixed flow areas.
Claim 6
Dependent Claim
35 words
Fluid pressure responsive control apparatus as claimed in claim 2 and further including: said first and second positions of said piston being defined by fixed spaced-apart stop means adapted to be engaged by said piston.
Claim 7
Dependent Claim
123 words
Fluid pressure responsive control apparatus as claimed in claim 2 wherein: said piston is unbalanced from said first position by a decrease in said control fluid pressure and movable in response to the force unbalance imposed thereon in a direction to close said first passage thereby causing a rapid drop in said control fluid pressure and corresponding increase in force unbalance imposed on said piston resulting in snap action movement of said piston into engagement with said stop means defining said second position; said second flow passage means being traversed and closed by said piston to produce a further decrease in said control fluid pressure thereby increasing the force unbalance imposed on said piston tending to hold the same in said second position.
Claim 8
Dependent Claim
116 words
Fluid pressure responsive control apparatus as claimed in claim 6 wherein: said piston is unbalanced from said second position by an increase in said control fluid pressure and movable in response to the resulting force unbalance imposed thereon in a direction to open said second passage thereby causing a rapid increase in force balance imposed on said piston resulting in snap action movement of said piston into engagement with said stop means defining said first position; said first flow passage means being traversed and opened by said piston to produce a further increase in said control fluid pressure thereby increasing the force unbalance imposed on said piston tending to hold the same in said second position.
Claim 9
Dependent Claim
69 words
Fluid pressure responsive control apparatus as claimed in claim 1 wherein: said signal producing means includes third flow passage means connected to said conduit means upstream from said first, second and third flow restrictions for providing an output pressure signal; said fluid pressure differential responsive means being operatively connected to said third flow passage means for controlling flow therethrough depending upon the position of said pressure differential responsive means.
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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |