US4760745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetoelastic torque transducer
Assignee: MYERSM FREDERICK M
•
Filing: 1986-12-05
•
Granted: 1988-08-02
•
Expires: 2006-12-05
Abstract
Abstract A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, the member including ferromagnetic, magnetostrictive means affixed to, associated with or forming a part of the surface of the torqued member for altering in magnetic permeability in response to the application of torque to the member. The ferromagnetic, magnetostrictive means is advantageously formed of nickel maraging steel, desirably 18% Ni maraging steel. Preferably, the transducer comprises a pair of axially spaced-apart annular bands defined within a region of the ferromagnetic, magnetostrictive means, the bands being endowed with residual stress created, respectively symmetrical right and left hand helically directed magnetic anisotropy of sufficiently large magnitude that the contribution to total magnetic anisotropy of any random anisotropy in the member is negligible. In a particularly preferred aspect of the invention, each said band has at least one circumferential region which is free of residually unstressed areas over at least 50% of its circumferential length.
Inventors
- 👤 Ivan J. Garshelis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:03
CPC Classifications
G; G01; G01L; G01L3/00; G01L3/02; G01L3/04; G01L3/10; G01L3/101; G01L3/102
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
154 words
A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, said member having a ferromagnetic and magnetostrictive region, said tranducer comprising: a pair of axially spaced-apart annular bands defined within said region, said bands having respectively symmetrical right and left hand helically directed residual stress-created magnetic anisotropy of sufficiently large magnitude compared with the random magnetic anisotropy in said member that the contribution to total magnetic anisotropy of any random is negligible, each said band having at least one circumferential region which is free of residually unstressed areas over at least 50% of its circumferential length; means for applying a cyclically time varying magnetic field to said bands; means for sensing the change in permeability of said bands caused by said applied torque; and, means for converting said sensed change in permeability to an electrical signal indicative of the magnitude of the torque applied to said member.
Claim 2
Dependent Claim
154 words
A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, said member having a ferromagnetic and magnetostrictive region, said tranducer comprising: a pair of axially spaced-apart annular bands defined within said region, said bands having respectively symmetrical right and left hand helically directed residual stress-created magnetic anisotropy of sufficiently large magnitude compared with the random magnetic anisotropy in said member that the contribution to total magnetic anisotropy of any random is negligible, each said band having at least one circumferential region which is free of residually unstressed areas over at least 50% of its circumferential length; means for applying a cyclically time varying magnetic field to said bands; means for sensing the change in permeability of said bands caused by said applied torque; and, means for converting said sensed change in permeability to an electrical signal indicative of the magnitude of the torque applied to said member.
Claim 3
Dependent Claim
34 words
A magnetoelastic torque transducer, as claimed in claim 1, wherein each said band has at least one circumferential region which is free of residually unstressed areas over at least 80% of its circumferential length.
Claim 4
Dependent Claim
27 words
A magnetoelastic torque transducer, as claimed in claim 1, wherein each said band has at least one continuous circumferential region which is free of residually unstressed areas.
Claim 5
Dependent Claim
18 words
A magnetoelastic torque transducer, as claimed in claim 1, wherein said region comprises the surface of said member.
Claim 6
Dependent Claim
21 words
A magnetoelastic torque transducer, as claimed in claim 1, wherein said region is rigidly affixed to the surface of said member.
Claim 7
Dependent Claim
30 words
A magnetoelastic torque transducer, as claimed in claim 1, wherein the magnetic easy axes in said bands are oriented, respectively, at angles of ±20°-60° to the axis of said member.
Claim 8
Dependent Claim
24 words
A magnetoelastic torque transducer, as claimed in claims 1, 4, 5, 2, 3 or 6, wherein said region is formed of nickel maraging steel.
Claim 9
Dependent Claim
19 words
A magnetoelastic torque transducer, as claimed in claim 7, wherein said region is formed of 18% Ni maraging steel.
Claim 10
Dependent Claim
100 words
In a magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member including ferromagnetic, magnetostrictive means associated with said member for altering in magnetic permeability in response to the application of torque to said member, means for applying a magnetic field to said ferromagnetic magnetostrictive means, means for sensing the change in permeability caused to said applied torque, and means for converting said sensed change in permeability to an electrical signal indicative of the magnitude of the torque applied to said member, the improvement comprising forming said ferromagnetic, magnetostrictive means from nickel maraging steel.
Claim 11
Dependent Claim
100 words
In a magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member including ferromagnetic, magnetostrictive means associated with said member for altering in magnetic permeability in response to the application of torque to said member, means for applying a magnetic field to said ferromagnetic magnetostrictive means, means for sensing the change in permeability caused to said applied torque, and means for converting said sensed change in permeability to an electrical signal indicative of the magnitude of the torque applied to said member, the improvement comprising forming said ferromagnetic, magnetostrictive means from nickel maraging steel.
Claim 12
Dependent Claim
20 words
A magnetoelastic torque transducer, as claimed in claim 9, wherein said ferromagnetic, magnetostrictive means comprises the surface of said member.
Claim 13
Dependent Claim
23 words
A magnetoelastic torque transducer, as claimed in claim 9, wherein said ferromagnetic, magnetostrictive means is rigidly affixed to the surface of said member.
Claim 14
Dependent Claim
24 words
A magnetoelastic torque transducer, as claimed in claims 9, 10 or 11, wherein said ferromagnetic, magnetostrictive means is formed of 18% Ni maraging steel.
Claim 15
Dependent Claim
117 words
A magnetoelastic torque transducer, as claimed in claims 9, 10 or 11, wherein at least a portion of said ferromagnetic, magnetostrictive means is endowed with helically directed residual stress created magnetic anisotropy, at least one circumferential region of said portion being free of residually unstressed areas over at least 50% of its circumferential length, said applying means applying said magnetic field to said endowed portion and to an area of said member not so endowed, said sensing means sensing the permeability difference between said portion and said area resulting from the application of torque to said member, said converting means converting said sensed permeability difference to an electrical signal indicative of the magnitude of the applied torque.
Claim 16
Dependent Claim
27 words
A magnetoelastic torque transducer, as claimed in claim 13, wherein said circumferential region is free of residually unstressed areas over at least 80% of its circumferential length.
Claim 17
Dependent Claim
26 words
A magnetoelastic torque transducer, as claimed in claim 13, wherein said portion has at least one continuous circumferential region which is free of residually unstressed areas.
Claim 18
Dependent Claim
93 words
A magnetoelastic torque transducer, as claimed in claims 9, 10 or 11, wherein said ferromagnetic, magnetostrictive means includes a pair of axially spaced-apart annular bands defined therewithin, said bands having respectively symmetrical right and left hand helically directed residual stress created magnetic anisotropy, each said band having at least one circumferential region which is free of residually unstressed areas over at least 50% of its circumferential length, said applying means applying said magnetic field to said bands, said sensing means sensing the change in permeability of said bands caused by said applied torque.
Claim 19
Dependent Claim
34 words
A magnetoelastic torque transducer, as claimed in claim 16, wherein each said band has at least one circumferential region which is free of residually unstressed areas over at least 80% of its circumferential length.
Claim 20
Dependent Claim
27 words
A magnetoelastic torque transducer, as claimed in claim 16, wherein each said band has at least one continuous circumferential region which is free of residually unstressed areas.
Claim 21
Dependent Claim
30 words
A magnetoelastic torque transducer, as claimed in claim 16, wherein the magnetic easy axes in said bands are oriented, respectively, at angles of ±20°-60° to the axis of said member.
Claim 22
Dependent Claim
134 words
A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, said member having a ferromagnetic and magnetostrictive region formed of nickel maraging steel, said transducer comprising: a pair of axially spaced-apart annular bands defined within said region, said bands having respectively symmetrical right and left hand helically directed residual stress-created magnetic anisotropy, each said band having at least one circumferential region which is free of residually unstressed areas over at least 50% of its circumferential length; means for applying a cyclically time varying magnetic field to said bands; means for sensing the change in permeability of said bands caused by said applied torque; and, means for converting said sensed change in permeability to an electrical signal indicative of the magnitude of the torque applied to said member.
Claim 23
Dependent Claim
134 words
A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, said member having a ferromagnetic and magnetostrictive region formed of nickel maraging steel, said transducer comprising: a pair of axially spaced-apart annular bands defined within said region, said bands having respectively symmetrical right and left hand helically directed residual stress-created magnetic anisotropy, each said band having at least one circumferential region which is free of residually unstressed areas over at least 50% of its circumferential length; means for applying a cyclically time varying magnetic field to said bands; means for sensing the change in permeability of said bands caused by said applied torque; and, means for converting said sensed change in permeability to an electrical signal indicative of the magnitude of the torque applied to said member.
Claim 24
Dependent Claim
34 words
A magnetoelastic torque transducer, as claimed in claim 20, wherein each said band has at least one circumferential region which is free of residually unstressed areas over at least 80% of its circumferential length.
Claim 25
Dependent Claim
27 words
A magnetoelastic torque transducer, as claimed in claim 20, wherein each said band has at least one continuous circumferential region which is free of residually unstressed areas.
Claim 26
Dependent Claim
21 words
A magnetoelastic torque transducer, as claimed in claims 20, 21 or 22, wherein said region comprises the surface of said member.
Claim 27
Dependent Claim
24 words
A magnetoelastic torque transducer, as claimed in claims 20, 21 or 22, wherein said region is rigidly affixed to the surface of said member.
Claim 28
Dependent Claim
22 words
A magnetoelastic torque transducer, as claimed in claims 20, 21 or 22, wherein said region is formed of 18% Ni maraging steel.
Claim 29
Dependent Claim
24 words
An internal combustion engine having a torque-carrying output member, said member including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 30
Dependent Claim
23 words
Power transmission means having a torque-carrying output member, said member including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 31
Dependent Claim
23 words
Fluid turbine means having a torque-carrying output member, said member including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 32
Dependent Claim
21 words
A weighing system including torque-carrying means, said means including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 33
Dependent Claim
37 words
A machine tool including means for causing relative rotation between a tool and a workpiece, said machine tool having a torque-carrying member, said member including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 34
Dependent Claim
38 words
A robotic device comprising mechanical means for performing work pursuant to pre-programmed or real time control instructions, said device having a torque-carrying member, said member including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 35
Dependent Claim
23 words
A vehicular steering system having torque-carrying shaft means, said means including a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 36
Dependent Claim
37 words
A force measuring system including means for converting a sensed force to torque, a torque transducer connected for sensing said torque, said torque transducer comprising a magnetoelastic torque transducer as claimed in claims 1, 9 or 20.
Claim 37
Dependent Claim
72 words
In a method of sensing the torque applied to a member having ferromagnetic, magnetostrictive means associated therewith which includes the steps of applying a magnetic field to said ferromagnetic magnetostrictive means, sensing the change in permeability caused by said applied torque and converting said sensed change in permeability to an electrical signal indicative of the magnitude of the applied torque, the improvement comprising forming said ferromagnetic, magnetostrictive means form nickel maraging steel.
Claim 38
Dependent Claim
72 words
In a method of sensing the torque applied to a member having ferromagnetic, magnetostrictive means associated therewith which includes the steps of applying a magnetic field to said ferromagnetic magnetostrictive means, sensing the change in permeability caused by said applied torque and converting said sensed change in permeability to an electrical signal indicative of the magnitude of the applied torque, the improvement comprising forming said ferromagnetic, magnetostrictive means form nickel maraging steel.
Claim 39
Dependent Claim
17 words
A method, as claimed in claim 34, wherein said nickel maraging steel is 18% Ni maraging steel.
Claim 40
Dependent Claim
62 words
A method, as claimed in claim 34, wherein said ferromagnetic, magnetostrictive means is endowed with a pair of axially spaced-apart annular bands having respectively symmetrical right and left hand helically directed residual stress-created magnetic anisotropy, the permeability difference between the bands is sensed, and said sensed permeability difference is converted to an electrical signal indicative of the magnitude of the applied torque.
Claim 41
Dependent Claim
95 words
In a method of sensing the torque applied to a member having a ferromagnetic and magnetostrictive region including the steps of endowing at least a portion of said region with helically directed magnetic anisotropy, applying a cyclically time varying magnetic field to said portions and to an area of said member not so endowed, and sensing the permeability difference between said portion and said area resulting from the application of torque to said member, the difference being indicative of the magnitude of the applied torque, the improvement comprising forming said region from nickel maraging steel.
Claim 42
Dependent Claim
95 words
In a method of sensing the torque applied to a member having a ferromagnetic and magnetostrictive region including the steps of endowing at least a portion of said region with helically directed magnetic anisotropy, applying a cyclically time varying magnetic field to said portions and to an area of said member not so endowed, and sensing the permeability difference between said portion and said area resulting from the application of torque to said member, the difference being indicative of the magnitude of the applied torque, the improvement comprising forming said region from nickel maraging steel.
Claim 43
Dependent Claim
162 words
In a method of sensing the torque applied to a member having a ferromagnetic and magnetostrictive region, including the steps of endowing a pair of axially spaced-apart annular bands within said region with respectively symmetrical right and left hand helically directed magnetic anisotropy, applying a cyclically time varying magnetic field to said bands, and sensing the permeability difference between said bands resulting from the application of torque to said member, the difference being indicative of the magnitude of the applied torque, the improvement comprising: defining said bands at the surface of said member and endowing said bands with magnetic anisotropy of sufficiently large magnitude compared with the random magnetic anisotropy in said member that the contribution to total magnetic anisotropy of any random anisotropy is negligible by instilling a residual stress distribution in each band which is sufficiently extensive that at least one circumferential region within each band is free of residually unstressed areas over at least 50% of its circumferential length.
Claim 44
Dependent Claim
162 words
In a method of sensing the torque applied to a member having a ferromagnetic and magnetostrictive region, including the steps of endowing a pair of axially spaced-apart annular bands within said region with respectively symmetrical right and left hand helically directed magnetic anisotropy, applying a cyclically time varying magnetic field to said bands, and sensing the permeability difference between said bands resulting from the application of torque to said member, the difference being indicative of the magnitude of the applied torque, the improvement comprising: defining said bands at the surface of said member and endowing said bands with magnetic anisotropy of sufficiently large magnitude compared with the random magnetic anisotropy in said member that the contribution to total magnetic anisotropy of any random anisotropy is negligible by instilling a residual stress distribution in each band which is sufficiently extensive that at least one circumferential region within each band is free of residually unstressed areas over at least 50% of its circumferential length.
Claim 45
Dependent Claim
33 words
A method, as claimed in claim 38, wherein said instilled residual stress distribution is sufficiently extensive that said region is free of residually unstressed areas over at least 80% of its circumferential length.
Claim 46
Dependent Claim
34 words
A method, as claimed in claim 38, wherein said instilled residual stress distribution is sufficiently extensive that each said band has at least one continuous circumferential region which is free of residually unstressed areas.
Claim 47
Independent Claim
19 words
A method, as claimed in claims 38, 39 or 40, wherein said region is formed of nickel maraging steel.
Claim 48
Dependent Claim
141 words
In a method of sensing the torque applied to a member having a ferromagnetic and magnetostrictive region, including the steps of endowing a pair of axially spaced-apart annular bands within said region with respectively symmetrical right and left hand helically directed magnetic anisotropy, applying an alternating magnetic field to said bands, and sensing the permeability difference between said bands resulting from the application of torque to said member, the difference being indicative of the magnitude of the applied torque, the improvement comprising: forming said region of nickel maraging steel, defining said bands at the surface of said member and endowing said bands with magnetic anisotropy by instilling a residual stress distribution in each band which is sufficiently extensive that at least one circumferential region within each band is free of residually unstressed areas over at least 50% of its circumferential length.
Claim 49
Dependent Claim
141 words
In a method of sensing the torque applied to a member having a ferromagnetic and magnetostrictive region, including the steps of endowing a pair of axially spaced-apart annular bands within said region with respectively symmetrical right and left hand helically directed magnetic anisotropy, applying an alternating magnetic field to said bands, and sensing the permeability difference between said bands resulting from the application of torque to said member, the difference being indicative of the magnitude of the applied torque, the improvement comprising: forming said region of nickel maraging steel, defining said bands at the surface of said member and endowing said bands with magnetic anisotropy by instilling a residual stress distribution in each band which is sufficiently extensive that at least one circumferential region within each band is free of residually unstressed areas over at least 50% of its circumferential length.
References Cited (Backward Citations)
SU274420A1
Cited
US3011340A
Cited
US3340729A
Cited
SU667836A1
Cited
SU838448A1
Cited
US4364278A
Cited
US4414855A
Cited
JPS589034A
Cited
US4631796A
Cited
US4506554A
Cited
US4627298A
Cited
JPS6079240A
Cited
JPS60192233A
Cited
US4598595A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |