US3700809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inductively coupled grid cursor
Assignee: Individual
•
Filing: 1971-08-31
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Granted: 1972-10-24
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Expires: 1991-08-31
Abstract
Abstract A cursor for taking position signals from a grid is includes a coil through which inductive coupling with the grid is established. Because inductive coupling is employed, there need be no physical contact between the cursor and the grid. The cursor is configured so that the effects of orientation changes of the sensor parallel to the plane of the grid are eliminated and the effects of orientation changes normal to the plane of the grid are minimized. Furthermore, the cursor includes a low reluctance magnetic element which provides a low impedance path for the magnetic flux within the cursor. An air gap is provided in the low reluctance element in the vicinity of the cursor which is in the closest proximity to the grid so that the magnetic field is concentrated at the grid, thereby permitting inductive coupling without the cursor physically contacting the grid.
Inventors
- 👤 Donald J Nadon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:26
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/204; G01D5/2066; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06F3/0354; G06F3/03545
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
123 words
A cursor for inductively coupling signals between said cursor and the conductors of a grid comprising: a low reluctance body portion providing a low impedance path for magnetic flux, said body portion having a tapered end to define a narrowed portion in the proximity of said grid; an air gap arranged in said body portion in the proximity of said end so that magnetic flux is concentrated at said end and intersects said grid conductors; said body portion supporting a coil element for establishing magnetic coupling between said cursor and said grid, said coil element and said portion having symmetry in a plane parallel to said grid so that orientation changes of said cursor in said plane has no effect on said coupling.
Claim 2
Dependent Claim
123 words
A cursor for inductively coupling signals between said cursor and the conductors of a grid comprising: a low reluctance body portion providing a low impedance path for magnetic flux, said body portion having a tapered end to define a narrowed portion in the proximity of said grid; an air gap arranged in said body portion in the proximity of said end so that magnetic flux is concentrated at said end and intersects said grid conductors; said body portion supporting a coil element for establishing magnetic coupling between said cursor and said grid, said coil element and said portion having symmetry in a plane parallel to said grid so that orientation changes of said cursor in said plane has no effect on said coupling.
Claim 3
Dependent Claim
28 words
The cursor of claim 1 wherein said narrowed portion is smaller than the spacing of adjacent conductors of said grid so that maximum coupling occurs at adjacent conductors.
Claim 4
Dependent Claim
20 words
The cursor of claim 2 wherein said body portion is a cylinder and contains an aperture for receiving said coil.
Claim 5
Dependent Claim
55 words
The cursor of claim 2 wherein said body portion is a hollow cylinder, and contains an annular slot extending from said narrowed portion through at least a portion of the length of said cylinder so that the opening of said slot forms said air gap, said slot supporting said coil concentrically with said body portion.
Claim 6
Dependent Claim
22 words
The cursor of claim 2 wherein said conductor spacing is at least twice as great as the dimension of said narrowed portion.
Claim 7
Dependent Claim
22 words
The cursor of claim 4 wherein said conductor spacing is at least twice as great as the dimension of said narrowed portion.
Claim 8
Dependent Claim
22 words
The cursor of claim 6 further including means for retaining a nonmagnetic closure portion on the other end of said body portion.
Claim 9
Dependent Claim
21 words
The cursor of claim 6 wherein the diameters of said body portion and said coil exceed one-half of said conductor spacing.
Claim 10
Dependent Claim
45 words
The cursor of claim 3 wherein said air gap is defined by said narrowed portion and the outer side of said cylinder, and said outer side is spaced further from said grid than said narrowed portion when said body cylinder is normal to said grid.
Claim 11
Dependent Claim
45 words
The cursor of claim 4 wherein said air gap is defined by said narrowed portion and the outer side of said cylinder, and said outer side is spaced further from said grid than said narrowed portion when said body cylinder is normal to said grid.
Claim 12
Dependent Claim
45 words
The cursor of claim 8 wherein said air gap is defined by said narrowed portion and the outer side of said cylinder, and said outer side is spaced further from said grid than said narrowed portion when said body cylinder is normal to said grid.
Claim 13
Dependent Claim
22 words
The cursor of claim 3 wherein said air gap is arranged in said narrowed portion and is substantially parallel to said grid.
Claim 14
Dependent Claim
21 words
The cursor of claim 4 wherein said air gap communicates with said annular slot and is substantially parallel to said grid.
Claim 15
Dependent Claim
21 words
The cursor of claim 8 wherein said air gap communicates with said annular slot and is substantially parallel to said grid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |