EP0182085B1
Expired / Lapsed
EP
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Position and speed sensors
Assignee: Dr Johannes Heidenhain GmbH
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Filing: 1985-10-14
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Granted: 1992-04-22
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Expires: 2005-10-14
Abstract
No abstract record available.
Inventors
- 👤 Francis Dr. Mcmullin
- 👤 John V. Byrne
- 👤 Aengus Murray
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 12:09
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/204; G01D5/2053; G01D2205/00; G01D2205/70; G01D2205/77
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
259 words
A sensor comprising a drive or exciting winding (121,124) for establishing a forward or drive field, at least one secondary or sense winding (122,125) in which a voltage may be induced in the presence of a said forward or drive field, at least one conductive screen (123,126) within which eddy currents are generated in the presence of a said forward or drive field to establish a counter-field opposing said forward field, and, optionally, at least one ferromagnetic part (158a, 158b), said at least one conductive screen (123,126) and said at least one secondary or sense winding (122,125) being displaceable relative to one another within said forward or drive field in substantially a single direction of relative displacement so that said at least one secondary or sense winding (122,125) may be shaded by said at least one conductive screen (123,126) to a varying extent to thereby vary the voltage induced in said at least one secondary or sense winding (122,125), characterised in that the nature and disposition of the drive or exciting winding (121, 124) is such that homogeneous magnetic flux is created in a region of the sensor in which field inhomogeneities are created by the presence of said at least one conductive screen (123, 126), that said at least one secondary or sense winding (122, 125) is within a substantially even or uniform field set up by said drive or exciting winding (121, 124), and that the sensor is either air-cored or said at least one ferromagnetic part (158a, 158b), where present, provides a ferromagnetic return flux path.
Claim 2
Dependent Claim
130 words
A sensor according to Claim 1, wherein said drive or exciting winding (124) is substantially solenoidal, said at least one secondary or sense winding (125) is a substantially solenoidal winding which is substantially concentric with the drive or exciting winding (124), said at least one conductive screen (126) has a substantially cylindrical surface region which is substantially concentric with said drive or exciting winding (124) and with said at least one secondary or sense winding (125), and said at least one conductive screen (126) and said at least one secondary or sense winding (125) are relatively displaceable in an axial direction relative to the substantially common axes of said cylindrical surface region, of said drive or exciting winding (124) and of said at least one secondary or sense winding (125).
Claim 3
Dependent Claim
97 words
A sensor according to Claim 1, wherein said drive or exciting winding (121) is generally planar, said at least one secondary or sense winding (122) is a substantially flat winding defining a notional surface which is substantially planar, said at least one conductive screen (123) has a surface region which is substantially parallel to said notional surface defined by said at least one secondary or sense winding (122), and said at least one secondary or sense winding (122) is substantially co-planar with said drive or exciting winding (121) or is located in a plane parallel to it.
Claim 4
Dependent Claim
32 words
A sensor according to Claim 3, wherein said at least one conductive screen (123) and said at least one secondary or sense winding (122) are relatively displaceable along a substantially linear path.
Claim 5
Dependent Claim
40 words
A sensor according to Claim 3, wherein said drive or exciting winding (28) is annular, and said at least one conductive screen (30) and said at least one secondary or sense winding (29) are relatively displaceable along a circular path.
Claim 6
Dependent Claim
45 words
A sensor according to Claim 5, wherein said drive or exciting winding (28) and said at least one secondary or sense winding (29) are stationary and said at least one conductive screen (30) is defined by a portion of a rotor (31) of the sensor.
Claim 7
Dependent Claim
110 words
A sensor according to Claim 1, wherein said at least one conductive screen (7) has a surface region which is substantially parallel to a notional surface defined by said at least one secondary or sense winding (6), said surface region is a sector of a cylindrical surface, said at least one secondary or sense winding (6) is disposed about the periphery of a notional cylinder substantially concentric with said cylindrical surface sector, and said at least one conductive screen (7) and said at least one secondary or sense winding (6) are relatively displaceable in a circumferential direction about the substantially common axis of said cylindrical surface and said notional cylinder.
Claim 8
Dependent Claim
153 words
A sensor according to any of Claims 3 to 7, wherein said at least one secondary or sense winding (142) has at least one coil having a pitch or extent in said single direction of relative displacement and said at least one conductive screen (141) has a pitch or extent in said single direction of relative displacement which is substantially equal to the pitch or extent of said at least one coil, said at least one conductive screen (141) having a dimension in a direction at right angles to said single direction of relative displacement which is substantially constant over said pitch or extent of said at least one conductive screen (141), and said at least one secondary or sense winding (142) having a dimension in a direction at right angles to said single direction of relative displacement which is substantially constant over said pitch or extent of said at least one coil.
Claim 9
Dependent Claim
64 words
A sensor according to any of Claims 3 to 8, wherein said at least one conductive screen (131) has a dimension in a direction at right angles to said single direction of relative displacement which is substantially equal to the maximum dimension of said at least one secondary or sense winding (130) in said direction at right angles to said direction of relative displacement.
Claim 10
Dependent Claim
182 words
A sensor according to any of Claims 3 to 7, wherein said at least one secondary or sense winding (135) has at least one coil having a pitch or extent in said single direction of relative displacement and said at least one conductive screen (134) has a pitch or extent in said single direction of relative displacement which is substantially equal to the pitch or extent of said at least one coil, said at least one conductive screen (134) having a dimension in a direction at right angles to said single direction of relative displacement, said at least one secondary or sense winding (135) having a dimension in a direction at right angles to said single direction of relative displacement, and at least one of said dimensions varying over the pitch or extent of said at least one conductive screen (134) or the pitch or extent of said at least one coil so that successive incremental net changes in unscreened area of said at least one secondary or sense winding (135) during said relative displacement are governed by a substantially sinusoidal function.
Claim 11
Dependent Claim
114 words
A sensor according to any of Claims 3 to 7, wherein said at least one secondary or sense winding (136) has at least one coil (136a,136b) having a pitch or extent in said single direction of relative displacement and said at least one conductive screen (137) has a pitch or extent in said single direction of relative displacement which is substantially different from the pitch or extent of said at least one coil (136a,136b), said at least one secondary or sense winding (136) having a dimension in a direction at right angles to said single direction of relative displacement which changes progressively over said pitch or extent of said at least one coil (136a,136b).
Claim 12
Dependent Claim
44 words
A sensor according to any of Claims 3 to 11, wherein said at least one secondary or sense winding has at least two series-connected coils (152, 154) and each of said at least two series-connected coils (152, 154) has a plurality of concentric turns.
Claim 13
Dependent Claim
160 words
A sensor according to any of Claims 3 to 12, wherein said at least one secondary or sense winding is a printed circuit winding having first and second tracks (152,154) disposed on opposite sides of a single board (157), each of said first and second tracks (152,154) having a plurality of concentric turns, the turns of the first track (152) extending inwardly from a first terminal (153) of said at least one secondary or sense winding to an interconnection (156) with the second track (154), said interconnection (156) passing through said board (157), and said second track (154) extending outwardly from said interconnection (156) to a second terminal (155) of said at least one secondary or sense winding, said first and second tracks (152,154) being disposed in an aligned back-to-back configuration, and the cross-overs between successive turns of each of said first and second tracks (152,154) being aligned with each other so that unbalanced electrical effects may be substantially minimized.
Claim 14
Dependent Claim
147 words
A sensor according to any preceding claim, comprising a further secondary or sense winding (144), the progressive shading of which during said relative displacement of said at least one conductive screen (145) and said at least one secondary or sense winding (143) proceeds in a manner substantially identical with the progressive shading of said at least one secondary or sense winding (143) during said relative displacement, wherein said further secondary or sense winding (144) is disposed relative to said at least one secondary or sense winding (143) so that the progressive shading of said further secondary or sense winding (144) during said relative displacement is spaced apart in time from that of said at least one secondary or sense winding (143), and the voltage variations in each said secondary or sense winding (143, 144) during said progressive shading follow a cyclic pattern and are in phase quadrature.
Claim 15
Dependent Claim
14 words
A sensor according to any preceding claim, comprising a plurality of conductive screens (140a,140b,140c).
Claim 16
Dependent Claim
81 words
Position-measuring apparatus comprising a first sensor according to Claim 1 and a second sensor according to Claim 15, wherein said single direction of displacement is the same direction for each of said sensors and said at least one secondary or sense winding of each of said sensors has a plurality of coils extending in said single direction of relative displacement, each successive coil in said single direction of relative displacement being wound in the opposite electrical sense to each adjacent coil.
References Cited (Backward Citations)
No citation records indexed.
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