Patent US4833919A successfully refreshed from Google Patents.
US4833919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring displacement
Assignee: Marelli Corp
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Filing: 1987-11-23
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Granted: 1989-05-30
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Expires: 2007-11-23
Abstract
Abstract Herein disclosed is a device for measuring a displacement of a movable member relative to a fixed member by putting the electromagnetic induction into practical use. The device comprises a first coil having first and second coil sections which are coaxially aligned along a common axis, a second coil arranged to establish a magnetic coupling with the first coil and extending along the common axis, and a short circuit ring arranged to establish a magnetic coupling with the first and second coils and movable relative to the same. The winding density of each of the first and second coil sections is gradually decreased from the outside end to the inside end thereof, and the winding density of the second coil is substantially even throughout the length of the same.
Inventors
- 👤 Yasuo Saito
- 👤 Koichi Shimizu
- 👤 Yuji Seki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:54
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/22; G01D5/225; G01D5/2275; G01D5/2283; G01F; G01F23/00; G01F23/30; G01F23/64; G01F23/68; G01F23/72; G01D2205/00; G01D2205/70; G01D2205/77; G01D2205/775; Y; Y10; Y10S; Y10S73/00; Y10S73/05
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
337 words
A device for measuring a displacement of a movable member relative to a fixed member, comprising: an AC signal source; a first coil mounted to said fixed member and including first and second coil sections which are electrically connected and coaxially aligned along a common axis so that the first coil has a first extreme end constituting an outside end of said first coil section, a middle portion defined between respective inside ends of said first and second coil sections and a second extreme end constituting an outside end of said second coil section; a second coil coaxially disposed within said first coil and mounted to said fixed member so as to establish a magnetic coupling with said first coil, an end of one of said first and second coils being connected to said AC signal source to receive an AC signal; a short circuit ring fixed for movement with said movable member, said short circuit ring being disposed upon and located at a predetermined position about said movable member and axially disposed about said first coil so as to establish a magnetic coupling with said first coil and second coil and constructed to consume magnetic energy; a float constituting said movable member and being connected to said short circuit ring to cause said short circuit ring to remain on top of a fluid; and means connected to an end of the other of said first and second coils for detecting a change in electromagnetic induction between said first coil and said second coil caused by said short circuit ring and for providing an information signal to a detecting circuit which is representative of said change; wherein the winding density of each of said first and second coil sections of said first coil is gradually decreased from the outside end to the inside end thereof, and the winding density of said second coil is substantially even throughout its length, and wherein the displacement of the float is measured as the float moves in response to a parameter.
Claim 2
Independent Claim
337 words
A device for measuring a displacement of a movable member relative to a fixed member, comprising: an AC signal source; a first coil mounted to said fixed member and including first and second coil sections which are electrically connected and coaxially aligned along a common axis so that the first coil has a first extreme end constituting an outside end of said first coil section, a middle portion defined between respective inside ends of said first and second coil sections and a second extreme end constituting an outside end of said second coil section; a second coil coaxially disposed within said first coil and mounted to said fixed member so as to establish a magnetic coupling with said first coil, an end of one of said first and second coils being connected to said AC signal source to receive an AC signal; a short circuit ring fixed for movement with said movable member, said short circuit ring being disposed upon and located at a predetermined position about said movable member and axially disposed about said first coil so as to establish a magnetic coupling with said first coil and second coil and constructed to consume magnetic energy; a float constituting said movable member and being connected to said short circuit ring to cause said short circuit ring to remain on top of a fluid; and means connected to an end of the other of said first and second coils for detecting a change in electromagnetic induction between said first coil and said second coil caused by said short circuit ring and for providing an information signal to a detecting circuit which is representative of said change; wherein the winding density of each of said first and second coil sections of said first coil is gradually decreased from the outside end to the inside end thereof, and the winding density of said second coil is substantially even throughout its length, and wherein the displacement of the float is measured as the float moves in response to a parameter.
Claim 3
Dependent Claim
19 words
A device as claimed in claim 1, in which said first coil is wound on an outer coil bobbin.
Claim 4
Dependent Claim
39 words
A device as claimed in claim 1, in which said first and second coil sections of said first coil are so arranged as to generate, upon electric energization of said first coil, respective magnetic fluxes in mutually opposed directions.
Claim 5
Dependent Claim
39 words
A device as claimed in claim 1, in which said first and second coil sections of said first coil are so arranged as to generate, upon electric energization of said second coil, respective induced electromotive forces mutually opposed directions.
Claim 6
Dependent Claim
46 words
A device as claimed in claim 1 wherein said detecting means comprises an analog switch operated in synchronism with said AC signal to pass predetermined portions of said AC signal induced in said second coil, and means for detecting a voltage level of said predetermined portions.
Claim 7
Dependent Claim
38 words
A device as claimed in claim 5 wherein said detecting means further includes a circuit receiving said AC signal and outputting a control signal to said analog switch to operate said analog switch to pass said predetermined portions.
Claim 8
Dependent Claim
14 words
A device as claimed in claim 6 wherein said predetermined portions are half wave.
Claim 9
Dependent Claim
49 words
A device as claimed in claim 1, in which an end portion of said second coil section which includes said second extreme end and an end portion of said second coil which faces said end portion of said second coil section are bent with respect to the common axis.
Claim 10
Dependent Claim
34 words
A device as claimed in claim 1, further comprising two additional coils of increased number of turns, said additional coils being connected to said first and second extreme ends of said first coil, respectively.
Claim 11
Dependent Claim
18 words
A device as claimed in claim 1, in which said short circuit ring is a closed circuit coil.
Claim 12
Dependent Claim
22 words
A device as claimed in claim 1, in which said short circuit ring is an annular member constructed of electrically conductive material.
Claim 13
Dependent Claim
17 words
A device as claimed in claim 11, in which said annular member is an annular metal plate.
Claim 14
Dependent Claim
23 words
A device as claimed in claim 1, in which said first and second coil sections of said first coil are connected in series.
Claim 15
Dependent Claim
23 words
A device as claimed in claim 1, in which said first and second coil sections of said first coil are connected in parallel.
Claim 16
Dependent Claim
32 words
A device as claimed in claim 1, in which said second coil is wound on an inner coil bobbin about which said outer coil bobbin and said first coil are coaxially disposed.
Claim 17
Dependent Claim
19 words
A device as claimed in claim 15, in which said inner coil bobbin is of a metal core type.
Claim 18
Dependent Claim
21 words
A device as claimed in claim 15, in which said outer and inner coil bobbins are constructed of a non-magnetic material.
Claim 19
Dependent Claim
38 words
A device as claimed in claim 15, further comprising two additional coils of increased number of turns, said two additional coils being respectively housed in annular recesses formed in axially opposed end portions of said outer coil bobbin.
Claim 20
Dependent Claim
27 words
A device as claimed in claim 18, in which said axially opposed end portions are constructed to serve as stoppers for restricting movement of said movable member.
Claim 21
Dependent Claim
30 words
A device as claimed in claim 18, in which said first coil is connected through said additional coils to said AC signal source to be fed with the AC signal.
Claim 22
Dependent Claim
30 words
A device as claimed in claim 18, in which said second coil is connected through said additional coils to said AC signal source to be fed with the AC signal.
Claim 23
Dependent Claim
66 words
A device as claimed in claim 18, further comprising a cylindrical case which receives therein a unit which includes said first and second coils, said two additional coils and the short circuit ring-mounted movable member, said cylindrical case having a plurality of holes for, when mounted in a liquid container, providing a fluid communication between the interior of the case and the exterior of the same.
Claim 24
Dependent Claim
24 words
A device as claimed in claim 22, in which said cylindrical case is formed with spaced stoppers for restricting movement of said movable member.
Claim 25
Dependent Claim
162 words
A device as claimed in claim 15, further comprising a third coil connected to said fixed member and coaxially disposed about said first coil to extend along the common axis within the range between said middle portion and said second extreme end, said third coil including third and fourth coil sections which are electrically connected and coaxially aligned so that said third coil has a third extreme end constituting an outside end of said third coil section, a middle portion defined between respective inside ends of said third and fourth coil sections and a fourth extreme end constituting an outside end of said fourth coil section, wherein said third and fourth coil sections of the third coil are so arranged as to generate, upon electric energization, respective magnetic fluxes which advance in the mutually opposed directions, and wherein the winding density of each of said third and fourth coil sections is gradually decreased from the outside end to the inside end thereof.
Claim 26
Dependent Claim
46 words
A device as claimed in claim 24, in which said first coil is connected with said AC signal source to be fed with an AC signal and in which said third coil is connected with another AC signal source to bed fed with an AC signal.
Claim 27
Dependent Claim
23 words
A device as claimed in claim 24, in which said first and second coil sections of said first coil are connected in series.
Claim 28
Dependent Claim
23 words
A device as claimed in claim 26, in which said third and fourth coil sections of said third coil are connected in series.
Claim 29
Dependent Claim
23 words
A device as claimed in claim 27, in which said third and fourth coil sections of said third coil are connected in parallel.
Claim 30
Dependent Claim
19 words
A device as claimed in claim 1, in which said second coil is wound on an inner coil bobbin.
Claim 31
Dependent Claim
19 words
A device as claimed in claim 29, in which said first coil is directly wound on said second coil.
Claim 32
Dependent Claim
19 words
A device as claimed in claim 30, in which the inner coil bobbin is of a metal core type.
Claim 33
Dependent Claim
19 words
A device as claimed in claim 30, in which said inner coil bobbin is constructed of a non-magnetic material.
Claim 34
Dependent Claim
25 words
A device as claimed in claim 30, in which said two additional coils are arranged at axially opposed end portions of said inner coil bobbin.
Claim 35
Dependent Claim
30 words
A device as claimed in claim 33, in which said first coil is connected through said additional coils to said AC signal source to be fed with the AC signal.
Claim 36
Dependent Claim
30 words
A device as claimed in claim 33, in which said second coil is connected through said additional coils to said AC signal source to be fed with the AC signal.
Claim 37
Dependent Claim
66 words
A device as claimed in claim 33, further comprising a cylindrical case which receives therein a unit which includes said first and second coils, said two additional coils and the short circuit ring-mounted movable member, said cylindrical case having a plurality of holes for, when mounted in a liquid container, providing a fluid communication between the interior of the case and the exterior of the same.
Claim 38
Dependent Claim
24 words
A device as claimed in claim 36, in which said cylindrical case is formed with spaced stoppers for restricting movement of said movable member.
Claim 39
Dependent Claim
162 words
A device as claimed in claim 30, further comprising a third coil connected to said fixed member and coaxially disposed about said first coil to extend along the common axis within the range, between said middle portion and said second extreme end, said third coil including third and fourth coil sections which are electrically connected and coaxially aligned so that said third coil has a third extreme end constituting an outside end of said third coil section, a middle portion defined between respective inside ends of said third and fourth coil sections and a fourth extreme end constituting an outside end of said fourth coil section, wherein said third and fourth coil sections of the third coil are so arranged as to generate, upon electric energization, respective magnetic fluxes which advance in the mutually opposed directions, and wherein the winding density of each of the third and fourth coil sections is gradually decreased from the outside end to the inside end thereof.
Claim 40
Dependent Claim
46 words
A device as claimed in claim 38, in which said first coil is connected with said AC signal source to be fed with an AC signal and in which said third coil is connected with another AC signal source to be fed with an AC signal.
Claim 41
Dependent Claim
155 words
A device as claimed in claim 1, further comprising a third coil connected to said fixed member and extending along the common axis within the range between said middle portion and said second extreme end, said third coil including third and fourth coil sections which are electrically connected and coaxially aligned so that said third coil has a third extreme end constituting an outside end of said third coil section, a middle portion defined between respective inside ends of said third and fourth coil sections and a fourth extreme end constituting an outside end of said fourth coil section, wherein said third and fourth coil sections of the third coil are so arranged as to generate, upon electric energization, respective magnetic fluxes which advance in the mutually opposed directions, and wherein the winding density of each of said third and fourth coil sections is gradually decreased from the outside end to the inside end thereof.
Claim 42
Dependent Claim
23 words
A device as claimed in claim 40, in which said first and second coil sections of said first coil are connected in parallel.
Claim 43
Dependent Claim
23 words
A device as claimed in claim 41, in which said third and fourth coil sections of said third coil are connected in series.
Claim 44
Dependent Claim
23 words
A device as claimed in claim 41, in which said third and fourth coil sections of said third coil are connected in parallel.
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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) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |