← Back to Patent Explorer
US4874005A Expired / Lapsed US ⏱️ 0.0 years remaining

Current to pressure tranducer employing magnetic fluid

Assignee: ALUM ROCK TECHNOLOGY A CA CORP
•
Filing: 1988-12-07
•
Granted: 1989-10-17
•
Expires: 2008-12-07
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A current-to-pressure transducer that is insensitive to shock employs a magnetic fluid that deforms a flexible diaphragm in response to an electrical input current that is applied to a coil and magnetic circuit. The deformed diaphragm varies the air space between the diaphragm and a nozzle connected to the air line so that the pressure within the air line is effectively controlled.

Inventors

  • 👤 Robert I. Potter

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 19:25
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/20; G05D16/2006; G05D16/2013; G05D16/024; Y; Y10; Y10T; Y10T137/00; Y10T137/2278; Y10T137/2409

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 89 words
A current-to-pressure transducer comprising: means for supplying a flow of air; first and second chambers and a means connecting said chambers, each of said chambers having an open end; magnetic fluid disposed within said chambers and said connection means; first and second flexible diaphragms respectively positioned against said open ends for containing said fluid within said chambers; and electromagnetic means energized by an input electrical current for coacting with said magnetic fluid to deform a selected one of said diaphragms thereby varying the air pressure in said supply means.
Claim 2
Dependent Claim 89 words
A current-to-pressure transducer comprising: means for supplying a flow of air; first and second chambers and a means connecting said chambers, each of said chambers having an open end; magnetic fluid disposed within said chambers and said connection means; first and second flexible diaphragms respectively positioned against said open ends for containing said fluid within said chambers; and electromagnetic means energized by an input electrical current for coacting with said magnetic fluid to deform a selected one of said diaphragms thereby varying the air pressure in said supply means.
Claim 3
Dependent Claim 48 words
A current-to-pressure transducer as in claim 1, wherein said electromagnetic means is positioned for coacting with said magnetic fluid in one of said chambers to deform a selected one of said diaphragms, and said air supply means is positioned for coacting with the other one of said diaphragms.
Claim 4
Dependent Claim 12 words
A current-to-pressure transducer as in claim 1 wherein the diaphragms are coplanar.
Claim 5
Dependent Claim 160 words
A current-to-pressure transducer comprising: a baseplate or housing made of magnetic material: at least one chamber formed in said baseplate, said chamber having at least one open end; at least one flexible membrane or diaphragm for sealing said open end; a volume of magnetic fluid contained within said chamber; air supply means disposed closely adjacent to said flexible membrane or diaphragm for supplying air; electromagnetic means comprising a magnetic circuit and a coil including permanent magnet means for receiving an input current to provide a magnetic field closely adjacent to said flexible membrane or diaphragm for displacing said flexible membrane or diaphragm relative to said air supply means so that the pressure of said air in said air supply means is regulated in accordance with said input current, wherein the displacement of said flexible membrane or diaphragm is accomplished with the volume of said magnetic fluid conserved and maintained constant and wherein said displacement is not opposed by ambient pressure.
Claim 6
Dependent Claim 160 words
A current-to-pressure transducer comprising: a baseplate or housing made of magnetic material: at least one chamber formed in said baseplate, said chamber having at least one open end; at least one flexible membrane or diaphragm for sealing said open end; a volume of magnetic fluid contained within said chamber; air supply means disposed closely adjacent to said flexible membrane or diaphragm for supplying air; electromagnetic means comprising a magnetic circuit and a coil including permanent magnet means for receiving an input current to provide a magnetic field closely adjacent to said flexible membrane or diaphragm for displacing said flexible membrane or diaphragm relative to said air supply means so that the pressure of said air in said air supply means is regulated in accordance with said input current, wherein the displacement of said flexible membrane or diaphragm is accomplished with the volume of said magnetic fluid conserved and maintained constant and wherein said displacement is not opposed by ambient pressure.
Claim 7
Dependent Claim 25 words
A current-to-pressure transducer as in claim 4, wherein said electromagnetic means comprises a magnetic tubular element and an said coil is wound about said element.
Claim 8
Dependent Claim 41 words
A current-to-pressure transducer as in claim 5, wherein said air supply means comprises a tube disposed coaxially within said magnetic tubular element, and a nozzle disposed at one end of said tube closely adjacent to said a flexible membrane or diaphragm.
Claim 9
Dependent Claim 21 words
A current-to-pressure transducer as in claim 4, including a magnetic piece positioned within said chamber adjacent to said membrane or diaphragm.
Claim 10
Dependent Claim 17 words
A current-to-pressure transducer as in claim 4, wherein an air space is provided within said magnetic fluid.
Claim 11
Dependent Claim 37 words
A current-to-pressure transducer as in claim 4, including a pressure sensing means, and an electronic feedback circuit for limiting the current to said electromagnetic means so that the pressure is substantially linearly related to the input current.
Claim 12
Dependent Claim 24 words
A current-to-pressure transducer as in claim 4 including means for maintaining said membrane or diaphragm in position at said open end of said chamber.

References Cited (Backward Citations)

US4053952A Cited
US4579137A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-16 1993-04-17 1993-10-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-16 1997-04-17 1997-10-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-16 2001-04-17 2001-10-17 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag