Patent US4621299A successfully refreshed from Google Patents.
US4621299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High energy degausser
Assignee: General Kinetics Inc
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Filing: 1982-11-05
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Granted: 1986-11-04
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Expires: 2002-11-05
Abstract
Abstract A magnetic material degausser in which the material to be degaussed is placed within the center of a degaussing coil. A capacitive discharge system is employed for energizing the degaussing coil. The capacitor is repeatedly discharged through the coil in such a way that for at least a portion of the degaussing cycle, the energy applied to the coil decreases with each energization. The magnetic material may be rotated within the coil as the degaussing cycle progresses. In one embodiment of the present invention, the energy discharged from the capacitor first increases and then decreases during the degaussing cycle with each energization of the coil. The rotational speed of the magnetic material within the coil may be related to the frequency at which the capacitor is discharged.
Inventors
- 👤 James D. Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:43
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/024; G11B5/0245; H; H01; H01F; H01F13/00; H01F13/006
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
99 words
Apparatus for degaussing a magnetized object comprising: means for storing energy: means for gradually applying energy to said storing means; means for monitoring the amount of energy stored in said storing means; and means, responsive to said monitoring means, for repeatedly releasing energy from said storing means to said object, said releasing means reducing the energy stored in said storage means as determined by said monitoring means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 2
Dependent Claim
99 words
Apparatus for degaussing a magnetized object comprising: means for storing energy: means for gradually applying energy to said storing means; means for monitoring the amount of energy stored in said storing means; and means, responsive to said monitoring means, for repeatedly releasing energy from said storing means to said object, said releasing means reducing the energy stored in said storage means as determined by said monitoring means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 3
Dependent Claim
12 words
Apparatus as in claim 1 wherein said storing means includes a capacitor.
Claim 4
Dependent Claim
12 words
Apparatus as in claim 1 wherein said releasing means includes a coil.
Claim 5
Dependent Claim
37 words
Apparatus as in claim 1 wherein said releasing means includes: means for generating a magnetic filed about said object; and said reversing means includes means for reversing the polarity of said magnetic field with each said repetition.
Claim 6
Dependent Claim
22 words
Apparatus as in claim 1 wherein said reversing means includes means for reversing the polarity of said energy by rotating said object.
Claim 7
Dependent Claim
12 words
Apparatus as in claim 1 wherein said object is magnetic recording tape.
Claim 8
Dependent Claim
104 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; a coil for surrounding said object, said coil including at least two separable sections to ease insertion and removal of said object; and means for repeatedly releasing energy from said storing means through said coil, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 9
Dependent Claim
104 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; a coil for surrounding said object, said coil including at least two separable sections to ease insertion and removal of said object; and means for repeatedly releasing energy from said storing means through said coil, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 10
Dependent Claim
24 words
Apparatus as in claim 7 wherein: said coil defined a space; and said apparatus further comprises means for mounting said object within said space.
Claim 11
Dependent Claim
15 words
Apparatus as in claim 2 wherein said reversing means includes means for rotating said object.
Claim 12
Dependent Claim
19 words
Apparatus as in claim 9 wherein said rotating means includes means for increasing the rotational speed of said object.
Claim 13
Dependent Claim
160 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; a coil defining a space; switch means, responsive to a trigger signal and connected in a circuit with said coil and said storing means, for selectively permitting current to flow through said circuit to generate a magnetic field in said space; means for repeatedly generating said trigger signal to cause the amount of energy stored in said storing means at the time of current flow to decrease with each current flow so that current flowing through said coil decreases with each trigger signal for at least a portion of a degaussing cycle; means for mounting said object in said space; and means for rotating said object within said space to reverse the polarity of said magnetic field with respect to said object over said repetitions, said rotating means gradually increasing the speed of rotation of said object over said repetitions.
Claim 14
Dependent Claim
160 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; a coil defining a space; switch means, responsive to a trigger signal and connected in a circuit with said coil and said storing means, for selectively permitting current to flow through said circuit to generate a magnetic field in said space; means for repeatedly generating said trigger signal to cause the amount of energy stored in said storing means at the time of current flow to decrease with each current flow so that current flowing through said coil decreases with each trigger signal for at least a portion of a degaussing cycle; means for mounting said object in said space; and means for rotating said object within said space to reverse the polarity of said magnetic field with respect to said object over said repetitions, said rotating means gradually increasing the speed of rotation of said object over said repetitions.
Claim 15
Dependent Claim
12 words
Apparatus as in claim 12 wherein said storing means includes a capacitor.
Claim 16
Dependent Claim
37 words
Apparatus as in claim 11 wherein said switching means includes a switching device for conducting current in a first direction and a diode connected in parallel with said switching device for conducting current in said second direction.
Claim 17
Dependent Claim
46 words
Apparatus as in claim 12 wherein said generating means includes: means for generating a control voltage that decreases during at least said portion of said degaussing cycle; and comparator means for producing said trigger voltage when a voltage across said storing means exceeds said control voltage.
Claim 18
Dependent Claim
18 words
Apparatus as in claim 14 further comprising electrically conductive, non-ferromagnetic blocks disposed in said space about said object.
Claim 19
Dependent Claim
12 words
Apparatus as in claim 15 wherein said blocks are made of aluminum.
Claim 20
Dependent Claim
51 words
Apparatus as in claim 11 wherein said trigger signal generating means includes means timing said trigger signals to cause the amount of current to flow to be initially greater than the degree of magnetization of said object and then gradually increase with each trigger signal before the current begins to decrease.
Claim 21
Dependent Claim
14 words
Apparatus as in claim 14 wherein said coil includes at least two separable sections.
Claim 22
Dependent Claim
126 words
Apparatus for degaussing a magnetic tape comprising: a capacitor; means for applying a charge to said capacitor; a coil defining a space; a silicon controlled rectifier connected in a circuit with said coil and said capacitor; a diode connected in parallel with said silicon controlled rectifier so as to have a polarity opposite to said silicon controlled rectifier; means for generating a control voltage that gradually increases and then decreases during a degaussing cycle; comparator means for producing a trigger signal for said silicon controlled rectifier when a signal related to a voltage across said capacitor exceeds said control voltage; means for rotatably mounting said tape in said space; and means for rotating said tape at a speed related to the frequency of said trigger signals.
Claim 23
Dependent Claim
126 words
Apparatus for degaussing a magnetic tape comprising: a capacitor; means for applying a charge to said capacitor; a coil defining a space; a silicon controlled rectifier connected in a circuit with said coil and said capacitor; a diode connected in parallel with said silicon controlled rectifier so as to have a polarity opposite to said silicon controlled rectifier; means for generating a control voltage that gradually increases and then decreases during a degaussing cycle; comparator means for producing a trigger signal for said silicon controlled rectifier when a signal related to a voltage across said capacitor exceeds said control voltage; means for rotatably mounting said tape in said space; and means for rotating said tape at a speed related to the frequency of said trigger signals.
Claim 24
Dependent Claim
18 words
Apparatus as in claim 19 further comprising electrically conductive, non-ferromagnetic blocks disposed in said space around said tape.
Claim 25
Dependent Claim
12 words
Apparatus as in claim 19 wherein said blocks are made of aluminum.
Claim 26
Independent Claim
86 words
A method for degaussing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; monitoring the amount of energy stored in said energy storage device; repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases, as determined by said monitoring step, is reduced with each release; and reversing the plurality of said energy with respect to said object.
Claim 27
Independent Claim
86 words
A method for degaussing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; monitoring the amount of energy stored in said energy storage device; repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases, as determined by said monitoring step, is reduced with each release; and reversing the plurality of said energy with respect to said object.
Claim 28
Dependent Claim
40 words
A method as in claim 22 wherein: said releasing step includes the step of generating a magnetic field about said object; and said reversing step includes the step of reversing the direction of said magnetic field with each said repetition.
Claim 29
Dependent Claim
24 words
A method as in claim 22 wherein said reversing step includes the step of reversing the polarity of said energy by rotating said object.
Claim 30
Dependent Claim
41 words
A method as in claim 22 wherein: said object is a magnetic recording tape; and said releasing step includes the steps of repeatedly applying said energy to a coil for generating a magnetic field and disposing said tape in said coil.
Claim 31
Dependent Claim
53 words
A method as in claim 25 wherein said releasing step includes the steps of: generating a control voltage that gradually decreases over at least said portion of a degaussing cycle; and producing a trigger signal for initiating said magnetic field generation when a voltage across said energy storage device exceeds said control voltage.
Claim 32
Dependent Claim
24 words
A method as in claim 25 wherein said reversing step includes the step of reversing the polarity of said energy is rotating said tape.
Claim 33
Dependent Claim
28 words
A method as in claim 27 wherein said rotating step includes the step of increasing the speed of rotation during at least a portion of a degaussing cycle.
Claim 34
Dependent Claim
22 words
A method as in claim 25 further comprising the step of disposing electrically conductive, non-ferromagnetic blocks in said coil about said tape.
Claim 35
Dependent Claim
42 words
A method as in claim 25 wherein said releasing step includes the step of applying the energy at a level higher than the degree of magnetization of said object and then gradually increasing the energy applied to said object before said reduction.
Claim 36
Independent Claim
95 words
A method for degaussing a magnetic tape comprising the steps of: gradually applying a charge to a capacitor; repeatedly conducting said charge on said capacitor through a coil defining a space in response to a trigger signal; alternately reversing the direction of said magnetic field; generating a control voltage that gradually increases and then decreases during a degaussing cycle; producing said trigger signal when a voltage across said capacitor exceeds said control voltage; rotatably mounting said tape in said space; and rotating said tape at a speed related to the frequency of said trigger signals.
Claim 37
Independent Claim
95 words
A method for degaussing a magnetic tape comprising the steps of: gradually applying a charge to a capacitor; repeatedly conducting said charge on said capacitor through a coil defining a space in response to a trigger signal; alternately reversing the direction of said magnetic field; generating a control voltage that gradually increases and then decreases during a degaussing cycle; producing said trigger signal when a voltage across said capacitor exceeds said control voltage; rotatably mounting said tape in said space; and rotating said tape at a speed related to the frequency of said trigger signals.
Claim 38
Dependent Claim
22 words
A method as in claim 31 further comprising the step of inserting electrically conductive, non-ferromagnetic blocks in said space around said tape.
Claim 39
Dependent Claim
116 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the timc of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions; and means for reapplying energy from said object to said storing means after having been released from said storing means to said object, said reapplying means recapturing energy in said degaussing apparatus to conserve energy.
Claim 40
Dependent Claim
116 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the timc of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions; and means for reapplying energy from said object to said storing means after having been released from said storing means to said object, said reapplying means recapturing energy in said degaussing apparatus to conserve energy.
Claim 41
Dependent Claim
95 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; and means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for increasing the frequency at which said releasing occurs during degaussing and means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 42
Dependent Claim
95 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; and means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for increasing the frequency at which said releasing occurs during degaussing and means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 43
Dependent Claim
33 words
Apparatus as in claim 33 wherein said reapplying means includes a diode coupled in parallel with said releasing means and biased to allow energy to flow from said object to said storing means.
Claim 44
Dependent Claim
105 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; a coil defining a space, said object being disposed in said space; electrically conductive, non-ferromagnetic blocks disposed in said space about said object; and means for repeatedly releasing energy from said storing means to said coil, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 45
Dependent Claim
105 words
Apparatus for degaussing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; a coil defining a space, said object being disposed in said space; electrically conductive, non-ferromagnetic blocks disposed in said space about said object; and means for repeatedly releasing energy from said storing means to said coil, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 46
Dependent Claim
12 words
Apparatus as in claim 36 wherein said blocks are made of aluminum.
Claim 47
Dependent Claim
88 words
Apparatus for deguassing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; and means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to first gradually increae and then gradually decrease the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 48
Dependent Claim
88 words
Apparatus for deguassing a magnetized object comprising: means for storing energy; means for gradually applying energy to said storing means; and means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to first gradually increae and then gradually decrease the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
Claim 49
Independent Claim
93 words
A method of degaussing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storing device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release; reversing the polarity of said energy with respect to said object; and reapplying energy to said energy storage device from said object after said energy has been released from said energy storage device to said object.
Claim 50
Independent Claim
93 words
A method of degaussing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storing device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release; reversing the polarity of said energy with respect to said object; and reapplying energy to said energy storage device from said object after said energy has been released from said energy storage device to said object.
Claim 51
Independent Claim
89 words
A method of deguassing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release; and rotating said object to reverse the polarity of said energy with respect to said object, said rotating step including the step of increasing the rotational speed of said object during degaussing.
Claim 52
Independent Claim
89 words
A method of deguassing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release; and rotating said object to reverse the polarity of said energy with respect to said object, said rotating step including the step of increasing the rotational speed of said object during degaussing.
Claim 53
Independent Claim
78 words
A method of degaussing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storing device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release, the frequency of said repeated releases increasing during degaussing; and reversing the polarity of said energy with respect to said object.
Claim 54
Independent Claim
78 words
A method of degaussing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storing device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release, the frequency of said repeated releases increasing during degaussing; and reversing the polarity of said energy with respect to said object.
Claim 55
Independent Claim
72 words
A method for deguassing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases first increases and then decreases with each release; and reversing the polarity of said energy with respect to said object.
Claim 56
Independent Claim
72 words
A method for deguassing a magnetized object comprising the steps of: gradually storing energy in an energy storage device; repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases first increases and then decreases with each release; and reversing the polarity of said energy with respect to said object.
References Cited (Backward Citations)
US3164753A
Cited
US2825854A
Cited
US3321586A
Cited
US3143689A
Cited
GB1098626A
Cited
GB1218515A
Cited
GB1204023A
Cited
US3638074A
Cited
US3938011A
Cited
US3895270A
Cited
US4142221A
Cited
GB2069259A
Cited
US4462059A
Cited
US4346426A
Cited
US4402032A
Cited
USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |