Patent US4561304A successfully refreshed from Google Patents.
US4561304A
Expired / Lapsed
US
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Positive displacement piston flowmeter
Assignee: Individual
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Filing: 1983-12-15
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Granted: 1985-12-31
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Expires: 2003-12-15
Abstract
Abstract A positive displacement radial piston flowmeter includes pistons coupled to one another by connecting rods. Fluid passageways interconnect the cylinders and inlet and outlet ports formed in the housing. Piston movement is sensed by a pair of linear differential transducers, including exciter and sensing windings, mounted over the outer end of two adjacent cylinders. An elongate piston extension carrying a magnetic material reciprocates within the coils. Each sensing coil produces a voltage difference having a sinusoidal wave form so the two transducers produce a two phase sinusoidal signal (when demodulated) which allows sensing and control circuitry to make very accurate flow measurements. The coil housing is constructed so the electromagnetic properties at both sensing coils are equal to eliminate the need to compensate for initial signal bias or signal drift. The pistons are attached to the outer ends of the connecting rods through a universal joint to compensate for manufacturing tolerances. The passageways fluidly connected to the cylinders are positioned so that the top of the passageways are about even with the highest point of the cylinder. This allows the meter to be self-purging as to air and vapor which may become trapped within the meter.
Inventors
- 👤 John K. Max
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:48
CPC Classifications
G; G01; G01F; G01F3/00; G01F3/02; G01F3/04; G01F3/14
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
125 words
A radial piston flowmeter comprising: a meter housing including means defining a fluid inlet and a fluid outlet; means defining a plurality of cylinders formed in said meter housing arranged in equally spaced radial directions about a central position, said cylinders defining cylinder inder axes; means defining passageways fluidly coupling said cylinders to said fluid inlet and said fluid outlet; a piston mounted within each said cylinder for reciprocal movement therein; and means for connecting said pistons to one another so movement of one piston causes corresponding movement of all of said pistons, said connecting means including connecting rods and universal joints coupling an end of said connecting rods to said pistons to reduce off axis forces applied to the pistons by the connecting rods.
Claim 2
Dependent Claim
125 words
A radial piston flowmeter comprising: a meter housing including means defining a fluid inlet and a fluid outlet; means defining a plurality of cylinders formed in said meter housing arranged in equally spaced radial directions about a central position, said cylinders defining cylinder inder axes; means defining passageways fluidly coupling said cylinders to said fluid inlet and said fluid outlet; a piston mounted within each said cylinder for reciprocal movement therein; and means for connecting said pistons to one another so movement of one piston causes corresponding movement of all of said pistons, said connecting means including connecting rods and universal joints coupling an end of said connecting rods to said pistons to reduce off axis forces applied to the pistons by the connecting rods.
Claim 3
Dependent Claim
16 words
The flowmeter of claim 1 comprising at least two pair of said cylinders and four pistons.
Claim 4
Dependent Claim
12 words
The flowmeter of claim 1 comprising four of said equally spaced cylinders.
Claim 5
Dependent Claim
13 words
The flowmeter of claim 1 wherein said pistons lie in a common plane.
Claim 6
Dependent Claim
76 words
The flowmeter of claim 1 wherein at least one of said passageways include means defining a first passageway having first and second ends, said first end in fluid communication with an outer region of one of said cylinders, a portion of said first end generally level with an upper region of said one cylinder when said cylinder axes are horizontal so a gas or a vapor in said outer region can pass through said first passageway.
Claim 7
Dependent Claim
28 words
The flowmeter of claim 5 wherein said first passageway includes means defining a plurality of first passageway segments having parallel axes arranged one on top of the other.
Claim 8
Dependent Claim
12 words
The flowmeter of claim 5 comprising a plurality of said first passageways.
Claim 9
Dependent Claim
44 words
The flowmeter of claim 5 wherein said second end is in fluid communication with an inner region of the adjacent cylinder, a portion of said second end being generally level with an upper region of the adjacent cylinder when said cylinder axes are horizontal.
Claim 10
Dependent Claim
20 words
The flowmeter of claim 2 wherein each of said connecting rods includes a solid link connecting two of said pistons.
Claim 11
Dependent Claim
11 words
The flowmeter of claim 1 wherein the pistons are solid graphite.
Claim 12
Dependent Claim
99 words
The flowmeter of claim 1 further comprising a linear differential transducer including: a transducer housing; a coil assembly including an exciter winding and a sensing winding, said exciter and sensing windings mounted within said transducer housing; means for mounting said transducer housing to said meter housing at one said cylinder so said exciter and sensing windings are coaxial with said one cylinder; and an elongate piston extension extending outwardly from an outer face of the piston within said one cylinder, a portion of said elongate piston extension being a magnetic material positioned for axial movement within said exciter winding.
Claim 13
Dependent Claim
39 words
The flowmeter of claim 11 wherein said sensing winding is made up of two coils, the coils electrically connected so their outputs are combined to produce a combination signal equal to the difference between the signal from each coil.
Claim 14
Dependent Claim
83 words
The flowmeter of claim 11 wherein: said transducer housing is a non-magnetic material defining a coil cavity sized for receipt of said exciter and sensing windings, said cavity open at one end to permit said coils to be mounted therein; and said transducer includes a cover plate mounted over the outermost of said windings at said open one end of said coil cavity, said cover plate sized to balance the electromagnetic effects produced by the housing at the other end of said cavity.
Claim 15
Dependent Claim
13 words
The flowmeter of claim 13 wherein said cover plate is a circular washer.
Claim 16
Dependent Claim
10 words
The flowmeter of claim 11 including a plurality of transducers.
Claim 17
Dependent Claim
23 words
The flowmeter of claim 11 including four equally spaced cylinders and first and second transducers mounted to the meter housing at adjacent cylinders.
Claim 18
Dependent Claim
24 words
The flowmeter of claim 13 wherein said coils are cylindrical and said coil cavity is annular and is sized for receipt of cylindrical coils.
Claim 19
Dependent Claim
117 words
The flowmeter of claim 1 wherein said universal joint includes a pin, a connector member mounted to one said piston and having an inner end with means defining a slot formed therein in a first plane and means defining a first bore intersecting said slot normal to said first plane, said connecting rod having an outer end sized for engagement within said slot and having means defining a second bore formed through said outer end coaxial with said first bore, said pin being slightly undersized with respect to at least one of said first and second bores to allow limited movement of said outer end relative to said connecting member in planes other than said first plane.
Claim 20
Dependent Claim
61 words
The flowmeter of claim 1 wherein said universal joint includes a pin connector including a threaded end sized to pass through means defining an axial hole in the piston and an enlarged end sized greater than the axial hole, the universal joint including a threaded member sized to threadedly engage said threaded end to secure said pin connector to said piston.
Claim 21
Dependent Claim
47 words
The flowmeter of claim 19 wherein said enlarged end includes means defining a recess facing said axial piston hole and a sealing member mounted within said recess, whereby tightening said threaded member forces said sealing member against the piston at a region surrounding the axial piston hole.
Claim 22
Dependent Claim
133 words
In a four piston flowmeter of the type including a meter housing containing four equally spaced, radially oriented means defining cylinders and pistons, the pistons coupled to one another through connecting rods and a link mechanism, the cylinders fluidly interconnected to each other and to means defining an inlet and an outlet in the housing by means defining fluid passageways, the improvement comprising: at least one of said passageways includes means defining a first passageway having first and second ends, said first end in fluid communication with an outer region of one of said cylinders, a portion of said first end generally level with an upper region of said one cylinder when said cylinder axes are horizontal so a gas or a vapor in said outer region can pass through said first passageway.
Claim 23
Dependent Claim
133 words
In a four piston flowmeter of the type including a meter housing containing four equally spaced, radially oriented means defining cylinders and pistons, the pistons coupled to one another through connecting rods and a link mechanism, the cylinders fluidly interconnected to each other and to means defining an inlet and an outlet in the housing by means defining fluid passageways, the improvement comprising: at least one of said passageways includes means defining a first passageway having first and second ends, said first end in fluid communication with an outer region of one of said cylinders, a portion of said first end generally level with an upper region of said one cylinder when said cylinder axes are horizontal so a gas or a vapor in said outer region can pass through said first passageway.
Claim 24
Dependent Claim
166 words
In a four piston flowmeter of the type including a meter housing containing four equally spaced, radially oriented means defining cylinders and pistons, the cylinders having cylinder axes, the pistons coupled to one another through connecting rods and a link mechanism, the cylinders interconnected to each other and to means defining an inlet and an outlet in the housing by means defining fluid passageways, the improvement comprising: a linear differential transducer including: a transducer housing; a winding assembly including an exciter winding and a sensing winding, said exciter and sensing windings mounted within said transducer housing; means for mounting said transducer housing to said meter housing at one said cylinder so said exciter and sensing windings are adjacent an extension of the axis of said one cylinder; and an elongate piston extension extending outwardly from an outer face of the piston within said one cylinder, a portion of said elongate piston extension being a magnetic material positioned for movement parallel to at least one said winding.
Claim 25
Dependent Claim
166 words
In a four piston flowmeter of the type including a meter housing containing four equally spaced, radially oriented means defining cylinders and pistons, the cylinders having cylinder axes, the pistons coupled to one another through connecting rods and a link mechanism, the cylinders interconnected to each other and to means defining an inlet and an outlet in the housing by means defining fluid passageways, the improvement comprising: a linear differential transducer including: a transducer housing; a winding assembly including an exciter winding and a sensing winding, said exciter and sensing windings mounted within said transducer housing; means for mounting said transducer housing to said meter housing at one said cylinder so said exciter and sensing windings are adjacent an extension of the axis of said one cylinder; and an elongate piston extension extending outwardly from an outer face of the piston within said one cylinder, a portion of said elongate piston extension being a magnetic material positioned for movement parallel to at least one said winding.
Claim 26
Dependent Claim
17 words
The flowmeter of claim 22 wherein said exciter and sensing windings are coaxial with said one cylinder.
Claim 27
Dependent Claim
17 words
The flowmeter of claim 22 wherein said magnetic material is positioned for reciprocal movement within said windings.
Claim 28
Dependent Claim
27 words
The flowmeter of claim 22 wherein one of said sensing and exciter windings includes a pair of coils located on either side of the other said winding.
Claim 29
Dependent Claim
21 words
The flowmeter of claim 25 wherein said sensing winding includes two sensing coils located on either side of said exciter winding.
Claim 30
Dependent Claim
33 words
The flowmeter of claim 26 wherein said sensing coils are electrically connected so their outputs are combined to produce a combination signal equal to the difference between the signals from said sensing coils.
References Cited (Backward Citations)
US168354A
Cited
US1885517A
Cited
US2014664A
Cited
US2116265A
Cited
US2746430A
Cited
US3024374A
Cited
US3101616A
Cited
US2981240A
Cited
US3344667A
Cited
US3657925A
Cited
US3757581A
Cited
US3906793A
Cited
US4023056A
Cited
US4217507A
Cited
US4450720A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |