US3743870A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moving coil linear actuator
Assignee: LTV LING ALTEC Inc
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Filing: 1972-06-28
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Granted: 1973-07-03
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Expires: 1992-06-28
Abstract
Abstract An electo-magnetic reciprocable motor employing plural slab permanent magnets and an essentially rectangular magnetic structure of the center-gap type. Typically, a square or rectangular drive coil of plural turns surrounds a central leg of the magnetic structure and is influenced by flux on all four sides. A single shorted-turn coil is stationary upon the central leg and is shorter than the central leg to provide reduction of inductance and damping. Longitudinal space is provided between each magnet to accommodate a mechanical take-off structure of stems attached to the drive coil and external electrical conductors connected thereto. A shorter single-ended version of the motor is also possible.
Inventors
- 👤 F Hunt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:13
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A linear positioning device comprising; a. a rectangular core structure including a rectangular center pole (12) and more than two separate rectangular parallelopiped outer plates (1,4,5,6) spaced therefrom by at least one separate end piece (2 or 3) to respectively define more than two elongated gaps as assembled, b. a rigid structure for reciprocative movement along said center pole, including a moving coil (16) of plural turns concentrically disposed around said center pole, threading each of said gaps, and having a mechanical load attached at one end, and c. a permanent slab magnet (7, 8, 9, 10) shorter than said outer plates mounted upon each of said outer plates and interposed in a said elongated gap adjacent to said moving coil, asymmetrically placed along the length of said gap nearest said mechanical load to produce only a unidirectional magnetic flux across said gap along the whole length thereof to pass through said moving coil.
Claim 2
Dependent Claim
154 words
A linear positioning device comprising; a. a rectangular core structure including a rectangular center pole (12) and more than two separate rectangular parallelopiped outer plates (1,4,5,6) spaced therefrom by at least one separate end piece (2 or 3) to respectively define more than two elongated gaps as assembled, b. a rigid structure for reciprocative movement along said center pole, including a moving coil (16) of plural turns concentrically disposed around said center pole, threading each of said gaps, and having a mechanical load attached at one end, and c. a permanent slab magnet (7, 8, 9, 10) shorter than said outer plates mounted upon each of said outer plates and interposed in a said elongated gap adjacent to said moving coil, asymmetrically placed along the length of said gap nearest said mechanical load to produce only a unidirectional magnetic flux across said gap along the whole length thereof to pass through said moving coil.
Claim 3
Dependent Claim
16 words
The device of claim 1 in which; a. the number of said outer plates is four.
Claim 4
Dependent Claim
33 words
The device of claim 1 in which; a. the width of each of said magnets is restricted to provide space at the corners of the rectangular assembly for elements of said rigid structure.
Claim 5
Dependent Claim
59 words
The device of claim 1, which additionally includes; a. a stationary shorted coil of sheet form (14) having at least one turn and disposed upon said center pole, being shorter than the longitudinal extent of said elongated gaps, and b. said shorted coil being disposed longitudinally in said elongated gap nearest said mechanical load attached to said rigid structure.
Claim 6
Dependent Claim
31 words
The device of claim 1 in which; a. an end piece (2, 3) is employed at each end of said outer plates, to reduce the external magnetic fields at said ends.
Claim 7
Dependent Claim
40 words
The device of claim 1 in which; a. an end piece (2) is employed at the end of said rectangular core structure adjacent to said mechanical load attached to said rigid structure, to minimize external magnetic field at said load.
Claim 8
Dependent Claim
34 words
The device of claim 1, which additionally includes; a. plural stems (17, 18, 19, 20) attached to the corners of said moving coil, and passing between adjacent elements of the rectangular core-permanent magnet assembly.
Claim 9
Dependent Claim
16 words
The device of claim 7 in which; a. said stems are formed of electrical insulating material.
Claim 10
Dependent Claim
22 words
The device of claim 8, which additionally includes; a. a flexible electrical connection from said moving coil attached to a said stem.
Claim 11
Dependent Claim
30 words
The device of claim 4 in which; a. the thickness of said shorted coil (14) is in the range of from one-half to equal that of said moving coil (16).
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |