US3875545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable reluctance transducer
Assignee: Data 100 Corp
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Filing: 1969-09-12
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Granted: 1975-04-01
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Expires: 1989-09-12
Abstract
Abstract A variable-reluctance transducer for sensing control indicia that are directly formed on a type carrier. The transducer contains an axial pole and a concentric cylindrical pole, in which are located a coil and a cylindrically-shaped magnet.
Inventors
- 👤 Robert H Curtiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:22
CPC Classifications
B; B41; B41J; B41J1/00; B41J1/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
A transducer for sensing the passage of moving spaced indicia comprising, in combination: A first pole piece of ferromagnetic material having an elongated portion terminating in a pole at one end, having a flat portion at the other end of the elongated portion, and having a cylindrically-shaped portion projecting from the periphery of the flat portion in a direction parallel to the elongated portion; a coil of electrically-conducting material surrounding at least part of the elongated portion of the first pole piece; a radially-polarized, cylindrically-shaped sleeve of permanent magnetic material surrounding the cylindrical-shaped portion of the first pole piece; and a second pole piece of ferromagnetic material having a cylindrical shape, having a length substantially equal to the length of the elongated portion of the first pole piece, surrounding the magnetic sleeve, and terminating in at least one pole at the end nearest the pole of the first pole piece.
Claim 2
Dependent Claim
150 words
A transducer for sensing the passage of moving spaced indicia comprising, in combination: A first pole piece of ferromagnetic material having an elongated portion terminating in a pole at one end, having a flat portion at the other end of the elongated portion, and having a cylindrically-shaped portion projecting from the periphery of the flat portion in a direction parallel to the elongated portion; a coil of electrically-conducting material surrounding at least part of the elongated portion of the first pole piece; a radially-polarized, cylindrically-shaped sleeve of permanent magnetic material surrounding the cylindrical-shaped portion of the first pole piece; and a second pole piece of ferromagnetic material having a cylindrical shape, having a length substantially equal to the length of the elongated portion of the first pole piece, surrounding the magnetic sleeve, and terminating in at least one pole at the end nearest the pole of the first pole piece.
Claim 3
Dependent Claim
32 words
The transducer described in claim 1, wherein the distance between the poles of the first and second pole pieces is an integral multiple of the distance between adjacent indicia to be sensed.
Claim 4
Dependent Claim
27 words
The transducer described in claim 1, wherein the pole of the first pole piece has a shape dependent upon the shape of an indicia to be sensed.
Claim 5
Dependent Claim
34 words
The transducer described in claim 1, wherein the flat portion of the first pole piece is substantially perpendicular to its elongated portion and wherein all cylindrically-shaped elements have the shapes of right circular cylinders.
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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |