US3708727A
Expired / Lapsed
US
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Method for adjusting the strength of high energy magnets
Assignee: Allen Bradley Co LLC
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Filing: 1971-07-22
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Granted: 1973-01-02
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Expires: 1991-07-22
Abstract
Abstract A high capability, oriented, ceramic permanent magnet is assembled into the magnetic circuit in which is intended to function, and its strength is reduced by demagnetization until it provides the desired flux density for the circuit. This demagnetization is accomplished by encircling the magnet with a demagnetizing coil and applying current pulses to the coil. Control over the degree of demagnetization is achieved by orienting the demagnetization field perpendicular to the direction of polarization of the magnet.
Inventors
- 👤 W Wielebski
- 👤 G Ray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:37
CPC Classifications
H; H01; H01F; H01F13/00; H01F13/006
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
52 words
In a method of demagnetizing high capability permanent magnets wherein a demagnetization field is momentarily applied to the magnet to reduce its strength, the improvement therein of applying the demagnetization field substantially perpendicular with respect to the direction of polarization of the magnet to provide greater control over the amount of demagnetization.
Claim 2
Dependent Claim
52 words
In a method of demagnetizing high capability permanent magnets wherein a demagnetization field is momentarily applied to the magnet to reduce its strength, the improvement therein of applying the demagnetization field substantially perpendicular with respect to the direction of polarization of the magnet to provide greater control over the amount of demagnetization.
Claim 3
Dependent Claim
31 words
The method as recited in claim 1, wherein the demagnEtization field is applied at an angle of greater than 80 degrees with respect to the direction of polarization of the magnet.
Claim 4
Dependent Claim
23 words
disposing an adjusting coil in position to apply a magnetic field substantially perpendicular to the direction of polarity of the permanent magnet; and
Claim 5
Dependent Claim
23 words
disposing an adjusting coil in position to apply a magnetic field substantially perpendicular to the direction of polarity of the permanent magnet; and
Claim 6
Dependent Claim
25 words
demagnetizing a high capability magnet therein by momentarily applying a demagnetization field substantially perpendicular with respect to the direction of polarization of the magnet; and
Claim 7
Dependent Claim
25 words
demagnetizing a high capability magnet therein by momentarily applying a demagnetization field substantially perpendicular with respect to the direction of polarization of the magnet; and
Claim 8
Dependent Claim
19 words
placing a demagnetizing coil around said cartridge with the coil axis paralleling the length of said reeds and magnet;
Claim 9
Dependent Claim
19 words
placing a demagnetizing coil around said cartridge with the coil axis paralleling the length of said reeds and magnet;
Claim 10
Dependent Claim
14 words
increasing the demagnetizing field until the magnet strength is reduced to a desired value.
Claim 11
Dependent Claim
14 words
increasing the demagnetizing field until the magnet strength is reduced to a desired value.
Claim 12
Dependent Claim
23 words
applying a pulse to said coil to create a demagnetizing field for said magnet that is substantially perpendicular to said direction of polarity;
Claim 13
Dependent Claim
23 words
applying a pulse to said coil to create a demagnetizing field for said magnet that is substantially perpendicular to said direction of polarity;
Claim 14
Dependent Claim
17 words
energizing said coil to reduce the magnetic strength of said magnet in said direction of magnetic polarity.
Claim 15
Dependent Claim
17 words
energizing said coil to reduce the magnetic strength of said magnet in said direction of magnetic polarity.
Claim 16
Dependent Claim
28 words
observing the effect of the demagnetization step on the operation of the magnetic circuit; wherein steps (2) and (3) are repeated until the desired circuit performance is obtained.
Claim 17
Dependent Claim
28 words
observing the effect of the demagnetization step on the operation of the magnetic circuit; wherein steps (2) and (3) are repeated until the desired circuit performance is obtained.
Claim 18
Dependent Claim
37 words
The method as recited in claim 1, wherein the high capability permanent magnet is made of ferrite material and is placed in a magnetic circuit prior to being demagnetized by repeated application of said momentary demagnetizing field.
Claim 19
Independent Claim
15 words
A method of constructing a magnetic circuit having a high capability magnet, the steps comprising:
Claim 20
Independent Claim
15 words
A method of constructing a magnetic circuit having a high capability magnet, the steps comprising:
Claim 21
Dependent Claim
11 words
testing the magnetic effect of the magnet upon said reeds; and
Claim 22
Dependent Claim
11 words
testing the magnetic effect of the magnet upon said reeds; and
Claim 23
Dependent Claim
39 words
The method as recited in claim 4, wherein said magnetic circuit includes a reed switch, the magnet is in magnetic circuit with the reed switch, and the effect of the demagnetization step is observed by operating the reed switch.
Claim 24
Dependent Claim
22 words
repeating steps (3) and (4), as necessary, with increasing increments of demagnetizing field strength until desired reed and magnet performance is obtained.
Claim 25
Dependent Claim
22 words
repeating steps (3) and (4), as necessary, with increasing increments of demagnetizing field strength until desired reed and magnet performance is obtained.
Claim 26
Dependent Claim
20 words
In a method of adjusting the magnetic strength of a high capability permanent magnet by partial demagnetization, the steps of:
Claim 27
Dependent Claim
20 words
In a method of adjusting the magnetic strength of a high capability permanent magnet by partial demagnetization, the steps of:
Claim 28
Dependent Claim
56 words
A method of adjusting the magnetic field of a high capability magnet as in claim 6, wherein the demagnetizing field comprises a series of alternating current pulses, there is a delay between pulses in which the magnet is tested, and the pulses are increased in magnitude until the magnet strength is reduced to a desired value.
Claim 29
Dependent Claim
37 words
A method of adjusting the magnetic field of a high capability magnet as in claim 6 wherein the demagnetizing field is applied at an angle greater than eighty degrees with respect to the selected direction of polarity.
Claim 30
Dependent Claim
37 words
A method of adjusting the magnetic field of a high capability magnet as in claim 7 wherein the demagnetizing field is applied at an angle greater than 80 degrees with respect to the selected direction of polarity.
Claim 31
Independent Claim
16 words
A method of constructing a switch circuit that includes a high capability magnet, the steps of:
Claim 32
Independent Claim
16 words
A method of constructing a switch circuit that includes a high capability magnet, the steps of:
Claim 33
Independent Claim
16 words
A method of constructing a switch circuit that includes a high capability magnet, the steps of:
Claim 34
Independent Claim
16 words
A method of constructing a switch circuit that includes a high capability magnet, the steps of:
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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |