Patent EP0253738A1 successfully refreshed from Google Patents.
Patent EP0054661A2 successfully refreshed from Google Patents.
EP0054661A2
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EP
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A capacitive transducer for sensing a home position
Assignee: International Business Machines Corp
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Filing: 1981-10-20
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Granted: —
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Expires: 2001-10-20
Abstract
Abstract A rotational shaft home position sensing transducer is provided which comprises a rotor (11) mounted on the shaft (10) having a planar surface with a first radial array of conductive elements (16) on the surface in combination with a fixedly mounted stator (12) having a planar surface parallel to the planar rotor surface and a second corresponding radial array of conductive elements (17) on the stator surface adjacent and spaced from the first array. The structure further contains a unit for applying an alternating electrical signal to the first array of elements and a unit connected to the second array of elements for sensing the capacitive effect induced in the second array by said electrical signal. The first and second arrays must be arranged so that a single home position in the relative motion between the rotor and stator will induce a single unique capacitive effect in the second plurality of elements. Particularly, the number of elements in the first and second array and their arrangement would be such that there is only a single rotational home position whereat all the elements in the first array are respectively aligned with the corresponding elements of the second array which will induce the single unique capacitive effect in this second array.
Inventors
- 👤 Darryl Ray Polk
- 👤 Errol Ray Williams, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 09:08
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/24; G01D5/241; G01D5/2412
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
170 words
A capacitive transducer for sensing a home position of a first moving member with relation to a second adjacent member characterized in that it comprises : a transmitter portion on one of said members having a planar surface and a first plurality of conductive elements arranged in a line on said surface, a receiver portion on the other of said member having a planar surface and a second plurality of corresponding conductive elements arranged in a line on said receiver surface, said second line of elements being adjacent to and spaced from said first line of elements, means for applying an alternating electrical signal to said first plurality of elements, and means connected to said second plurality of elements for sensing the capacitive effect induced in said second elements by said electrical signal, said first and second pluralities of elements being arranged so that only a single home position in the relative motion between said two members will induce a single unique capacitive effect in said second plurality of elements.
Claim 2
Dependent Claim
170 words
A capacitive transducer for sensing a home position of a first moving member with relation to a second adjacent member characterized in that it comprises : a transmitter portion on one of said members having a planar surface and a first plurality of conductive elements arranged in a line on said surface, a receiver portion on the other of said member having a planar surface and a second plurality of corresponding conductive elements arranged in a line on said receiver surface, said second line of elements being adjacent to and spaced from said first line of elements, means for applying an alternating electrical signal to said first plurality of elements, and means connected to said second plurality of elements for sensing the capacitive effect induced in said second elements by said electrical signal, said first and second pluralities of elements being arranged so that only a single home position in the relative motion between said two members will induce a single unique capacitive effect in said second plurality of elements.
Claim 3
Dependent Claim
27 words
The capacitive transducer of claim 1 wherein said first and second pluralities of elements are respectively arranged circular lines whereby said transducer senses a rotational home position.
Claim 4
Dependent Claim
71 words
The capacitive transducer of claim 2 wherein the number of elements in said first and second pluralities and the arrangement of said elements along their respective lines are selected so that there is only a single rotational home position whereat all of the elements in said first plurality are respectively aligned with corresponding elements in said second plurality to induce said single unique capacitive effect in said second plurality of elements.
Claim 5
Dependent Claim
34 words
The capacitive transducer of claim 3 wherein said unique capacitive effect is a voltage level which is on one level for all non-home positions and at a substantially different level for said home position.
Claim 6
Dependent Claim
136 words
A rotational shaft home position sensing transducer comprising: a rotor mounted on said shaft having a planar surface and a first radial array of conductive elements on said surface, a fixedly mounted stator having a planar surface parallel to said planar rotor surface and a second corresponding radial array of conductive elements on said stator surface adjacent to and spaced from said first array, means for applying an alternating electrical signal to said first array of elements, and means connected to said second array of elements for sensing the capacitive effect induced in said second array by said electrical signal, said first and second arrays being arranged so that only a single home position in the relative motion between said rotor and stator will induce a single unique capacitive effect in said second plurality of elements.
Claim 7
Dependent Claim
136 words
A rotational shaft home position sensing transducer comprising: a rotor mounted on said shaft having a planar surface and a first radial array of conductive elements on said surface, a fixedly mounted stator having a planar surface parallel to said planar rotor surface and a second corresponding radial array of conductive elements on said stator surface adjacent to and spaced from said first array, means for applying an alternating electrical signal to said first array of elements, and means connected to said second array of elements for sensing the capacitive effect induced in said second array by said electrical signal, said first and second arrays being arranged so that only a single home position in the relative motion between said rotor and stator will induce a single unique capacitive effect in said second plurality of elements.
Claim 8
Dependent Claim
70 words
The transducer of claim 5 wherein the number of elements in said first and second arrays and the arrangement of said elements in their respective arrays are selected so that there is only a single rotational home position whereat all of the elements in said first array are respectively aligned with corresponding elements in said second array to induce said single unique capacitive effect in said second array of elements.
Claim 9
Dependent Claim
33 words
The transducer of claim 6 wherein said unique capacitive effect is a voltage level which is on one level for all non-home positions and at a substantially different level for said home position.
Claim 10
Dependent Claim
92 words
The transducer of claim 7 wherein the elements in said first array and in said second array are respectively arranged in a plurality of radial element positions, the quantity of said element positions in each of said arrays being determined by the equation: P = 2 n - 1, where P is the quantity of element positions and n is a positive integer, and the selected number and arrangement of said elements in said element positions providing an uncorrelated maximal length linear sequence of elements for 2 n - 1 element positions.
References Cited (Backward Citations)
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