CA1223303A - Treating ferromagnetic materials to increase wear resistance - Google Patents
Treating ferromagnetic materials to increase wear resistanceInfo
- Publication number
- CA1223303A CA1223303A CA000433346A CA433346A CA1223303A CA 1223303 A CA1223303 A CA 1223303A CA 000433346 A CA000433346 A CA 000433346A CA 433346 A CA433346 A CA 433346A CA 1223303 A CA1223303 A CA 1223303A
- Authority
- CA
- Canada
- Prior art keywords
- pulses
- magnetic field
- control
- field pulses
- amplitude
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F13/00—Apparatus or processes for magnetising or demagnetising
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Chemical Vapour Deposition (AREA)
- Vending Machines For Individual Products (AREA)
- Magnetic Treatment Devices (AREA)
- Generation Of Surge Voltage And Current (AREA)
- Soft Magnetic Materials (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Hard Magnetic Materials (AREA)
- Feedback Control In General (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Liquid Crystal Substances (AREA)
- Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
A method which treats ferromagnetic materials with magnetic field pulses having preset repetition fre-quency, amplitude and width, which materials are demagnetized at the end of the treatment. The magnetic field pulses include positive pulses and negative pulses, the amplitude ratio of the positive to the negative pulses is 1,8; 0,2, and the magnetic field pulses of one polarity repeat with an equal or lower frequency compared with the repetition frequency of the pulses of the other polarity. At the end of the treatment, the amplitude of the magnetic field pulses is gradually attenuated. This treating method has the advan-tage of improving the wear resistance of the treated mate-rials.
A method which treats ferromagnetic materials with magnetic field pulses having preset repetition fre-quency, amplitude and width, which materials are demagnetized at the end of the treatment. The magnetic field pulses include positive pulses and negative pulses, the amplitude ratio of the positive to the negative pulses is 1,8; 0,2, and the magnetic field pulses of one polarity repeat with an equal or lower frequency compared with the repetition frequency of the pulses of the other polarity. At the end of the treatment, the amplitude of the magnetic field pulses is gradually attenuated. This treating method has the advan-tage of improving the wear resistance of the treated mate-rials.
Description
The present invention relates to a method and a device for treating ferromagnetic materials, which method and device can be used in engineering industries.
A known method for the treatment o~ ferroma-S gnetic materials consists in produclng unipolar magneticfield pulses of specified repeti-tion frequency, amplitude ar~d width. The ferromagnetic material is introduced in the magnetic field, and it is then subjected to complete dema-gnetization.
A known device for carrying out into practice this prior art method comprises a current source, a genera-tor of unipolar electric pulses adjustable in terms of ampli-tude and frequency, a magnetic field generator which includes a coil for producing the magnetic field in which the ferro-magnetic material is introduced, all connected in series, and a control unit connected to the current source.
A disadvantage of the above described prior art method and device is the low wear resistance of the treated ferromagnetic materials.
An object of the present invention is therefore to provide a method and a device which treat Eerromagnetic materials so as to improve their wear xesistance.
According to the invention, there is provided a method for treating ferromagnetic materials with magnetic field pulses having preset repetition frequency, amplitude and width, said materials being demagnetized at the end of the treatment, wherein the magnetic field pulses include positive pulses and negative pulses, the amplitude ratio of the positive to the negative pulses is 1,8; 0,2,and the magnetic field pulses of one polarity repeat with an equal or lower frequency compared with the repetition frequency of the pulses of the other polarity.
Preferably, at the end of the treatment, the amplitude of the magnetic field pulses is gradually reduced 3;3~
to zero.
~ lso in accordance with -the invention, there is provided a device for treating ferromagnetic materials . with magnetic Eield pulses having preset repetition fre-quency, amplitude and width, said ma-terials being demagne-tized at the end of the -treatment, said treating device comprising:
a magnetic field pulse generator comprising a first and a second generating units each including a cpacitor and a coil interconnected i.n series, and a thyris-tor connected in parallel with the serially interconnected capacitor and coil, each thyris-tor being provided with an anode, a control electrode and a cathode connected to a reEerence voltage, said magnetic field pulses being generated through said coils and the coil of said first unit being connected to generate positive magnetic field pulses while the coil of said second unit is connected to generate nega-tive magnetic field pulses;
a controllable rectifier for applying a first vol-tage to the anode of the thyristor of said first generating unit, and for applying a second voltage to the anode of the thyristor of said second generating uni-t, the amplitude of said first and second voltages being adjusted so that the amplitude ratio of the positive to the negative magnetic field pulses is 1,8; 0,2;
control pulse generating means including a first output for delivering control pulses to the control electrode of the thyristor of said first generating unit, and a second output for delivering control pulses to the control electrode of the thyristor of said second generating unit, said control pulses controlling operation of said thyristors to cause production thro.ugh said coils of magnetic field pulses of one polarity which repeat with an equal or lower frequency compared with the repetition frequency of the magnetic field pulses of the other polari-ty; and control means for controlling operation of said rectifier and said con-trol pulse generating means.
- As already mentioned hereinabove, the method and device of the present invention have the advantage of lmproving the wear resistance of the treated ferromagnetic materials.
The objects, advantages and other features of the present invention will become more apparent upon reading of the following non restrictive description thereof, made with reference to the accompanying drawing which represents, under the form of block diagram, a preferred embodimen-t of the device according to the present invention.
Referring now to the attached drawing , the device according to the present invention comprises a magne-tic field pulse generator 5. This generator comprises two similar, separate generating units. The first generating unit comprises a capacitor 6 connected in series with a coil 7, as well as a thyristor 8 connected in parallel with the serially interconnected capacitor 6 and coil 7O As can be seen, the cathode 82 of the thyristor 8 is grounded.
Accordingly, the second generating unit of the magnetic field pulse generator 5 includes a capacitor 6' connected in series with a coil 7'~ and a thyristor 8' connected in parallel with the serially interconnected capacitor 6' and coil 7'.
The cathode 85 of the thyristor 8' is also grounded.
The magnetic field pulses produced through the coils 7 and 7' are applied to a ferromagnetic material 9 positioned in the proximity of these two coils. As can be seen on the attached drawing, the two coils of the generator 5 are so connected that the coil 7 produces positive magnetic field pulses while the coil 7' generates negative magnetic field pulses. Each coil 7, 7' may be provided with a magnetic core, not shown in the attached drawing.
The device in accordance with the present invention further comprises a controllable, adjustable recti.Eier 2 which is supplied through its input 21 by a supply alternating voltage 0~ The rectifier 2 applies through its output terminal 22 a first direct curren-t voltage to the anode 81 of the -thyristor 8, and also applies through its output 23 a second di.rect current voltage to the anode 84 of the thyristor 8'.
A control pulse generator 3 supplies through its output 31 control pulses on the control electrode 83 of the thyris-tor 8. The generator 3 also supplies through its output 32 control pulses to the controi electrode 86 of the thyristor 8'. The control pulses from the generator 3 therefo:re control production of the positive and negative magnetic field pulses through the coils 7 and 7' by controlling operation of the thyristors 8 and 8', as will be seen in more details herei..nafter.
A trigger coil 10 surrounding the material 9 is responsive to the magnetic field pulses applied to this ferromagnetic material to produce a signal on an input 41 of a control unit 4. This unit 4 supplies in accordance with the signal on its input 41 control pulses to the rectifier 2 and the generator 3 through its outputs 43 and 42, respec-tively, so as to control operation of these rectifier 2 and generator 3.
A current source 1 receiving on its input 11 the alternating voltage 0 supplies through its outputs 12, 13 and 14 a direct current to the rectifier 2, the gene rator 3 and the control unit 4, so as to supply these rectifier
A known method for the treatment o~ ferroma-S gnetic materials consists in produclng unipolar magneticfield pulses of specified repeti-tion frequency, amplitude ar~d width. The ferromagnetic material is introduced in the magnetic field, and it is then subjected to complete dema-gnetization.
A known device for carrying out into practice this prior art method comprises a current source, a genera-tor of unipolar electric pulses adjustable in terms of ampli-tude and frequency, a magnetic field generator which includes a coil for producing the magnetic field in which the ferro-magnetic material is introduced, all connected in series, and a control unit connected to the current source.
A disadvantage of the above described prior art method and device is the low wear resistance of the treated ferromagnetic materials.
An object of the present invention is therefore to provide a method and a device which treat Eerromagnetic materials so as to improve their wear xesistance.
According to the invention, there is provided a method for treating ferromagnetic materials with magnetic field pulses having preset repetition frequency, amplitude and width, said materials being demagnetized at the end of the treatment, wherein the magnetic field pulses include positive pulses and negative pulses, the amplitude ratio of the positive to the negative pulses is 1,8; 0,2,and the magnetic field pulses of one polarity repeat with an equal or lower frequency compared with the repetition frequency of the pulses of the other polarity.
Preferably, at the end of the treatment, the amplitude of the magnetic field pulses is gradually reduced 3;3~
to zero.
~ lso in accordance with -the invention, there is provided a device for treating ferromagnetic materials . with magnetic Eield pulses having preset repetition fre-quency, amplitude and width, said ma-terials being demagne-tized at the end of the -treatment, said treating device comprising:
a magnetic field pulse generator comprising a first and a second generating units each including a cpacitor and a coil interconnected i.n series, and a thyris-tor connected in parallel with the serially interconnected capacitor and coil, each thyris-tor being provided with an anode, a control electrode and a cathode connected to a reEerence voltage, said magnetic field pulses being generated through said coils and the coil of said first unit being connected to generate positive magnetic field pulses while the coil of said second unit is connected to generate nega-tive magnetic field pulses;
a controllable rectifier for applying a first vol-tage to the anode of the thyristor of said first generating unit, and for applying a second voltage to the anode of the thyristor of said second generating uni-t, the amplitude of said first and second voltages being adjusted so that the amplitude ratio of the positive to the negative magnetic field pulses is 1,8; 0,2;
control pulse generating means including a first output for delivering control pulses to the control electrode of the thyristor of said first generating unit, and a second output for delivering control pulses to the control electrode of the thyristor of said second generating unit, said control pulses controlling operation of said thyristors to cause production thro.ugh said coils of magnetic field pulses of one polarity which repeat with an equal or lower frequency compared with the repetition frequency of the magnetic field pulses of the other polari-ty; and control means for controlling operation of said rectifier and said con-trol pulse generating means.
- As already mentioned hereinabove, the method and device of the present invention have the advantage of lmproving the wear resistance of the treated ferromagnetic materials.
The objects, advantages and other features of the present invention will become more apparent upon reading of the following non restrictive description thereof, made with reference to the accompanying drawing which represents, under the form of block diagram, a preferred embodimen-t of the device according to the present invention.
Referring now to the attached drawing , the device according to the present invention comprises a magne-tic field pulse generator 5. This generator comprises two similar, separate generating units. The first generating unit comprises a capacitor 6 connected in series with a coil 7, as well as a thyristor 8 connected in parallel with the serially interconnected capacitor 6 and coil 7O As can be seen, the cathode 82 of the thyristor 8 is grounded.
Accordingly, the second generating unit of the magnetic field pulse generator 5 includes a capacitor 6' connected in series with a coil 7'~ and a thyristor 8' connected in parallel with the serially interconnected capacitor 6' and coil 7'.
The cathode 85 of the thyristor 8' is also grounded.
The magnetic field pulses produced through the coils 7 and 7' are applied to a ferromagnetic material 9 positioned in the proximity of these two coils. As can be seen on the attached drawing, the two coils of the generator 5 are so connected that the coil 7 produces positive magnetic field pulses while the coil 7' generates negative magnetic field pulses. Each coil 7, 7' may be provided with a magnetic core, not shown in the attached drawing.
The device in accordance with the present invention further comprises a controllable, adjustable recti.Eier 2 which is supplied through its input 21 by a supply alternating voltage 0~ The rectifier 2 applies through its output terminal 22 a first direct curren-t voltage to the anode 81 of the -thyristor 8, and also applies through its output 23 a second di.rect current voltage to the anode 84 of the thyristor 8'.
A control pulse generator 3 supplies through its output 31 control pulses on the control electrode 83 of the thyris-tor 8. The generator 3 also supplies through its output 32 control pulses to the controi electrode 86 of the thyristor 8'. The control pulses from the generator 3 therefo:re control production of the positive and negative magnetic field pulses through the coils 7 and 7' by controlling operation of the thyristors 8 and 8', as will be seen in more details herei..nafter.
A trigger coil 10 surrounding the material 9 is responsive to the magnetic field pulses applied to this ferromagnetic material to produce a signal on an input 41 of a control unit 4. This unit 4 supplies in accordance with the signal on its input 41 control pulses to the rectifier 2 and the generator 3 through its outputs 43 and 42, respec-tively, so as to control operation of these rectifier 2 and generator 3.
A current source 1 receiving on its input 11 the alternating voltage 0 supplies through its outputs 12, 13 and 14 a direct current to the rectifier 2, the gene rator 3 and the control unit 4, so as to supply these rectifier
2, generator 3 and unit 4 with electric energy required for operation thereof.
In operatlon, the direct current voltage on the rectifier output 22 charges the capacitor 6 when the thyristor 8 is in the off state. Accordingly, the direct 33~33 current voltage on the rectifier output 23 charges the capa-citor 6' when the thyristor 8 7 iS in -the off state. As soon as a con-trol pulse is applied on the control electrode 83 - th:rough the output 31 of the generator 3, the thyristor 8 becomes .in the on state and a current i flows in the loop Eormed by the thyristor 8, the coil 7 and the capacitor 6 to produce a positive magnetic field pulse through the coil 7. In the same manner, as soon as a control pulse is trans-mitted to the control electrode 86 through the output 32 of the generator 3, the thyristor 8' becomes in -the on state and the capacitor 6' discharges into the coil 7' through the thyristor 8' in order to produce a current i' into this coil 7' so as to generate a negative magnetic field pulse. As soon as the voltage between the anode and the cathode of each thyristor 8, 8' becomes negative, this thyristor is switched back into the off state.
It can therefore be easily appreciated that by controlling supplying of the control pulses through the outputs 31 and 32 of the generator 3, positive and negative magnetic field pulses can be consecutively produced through the coils 7 and 7'.
In order to improve the wear resistance of the treated ferromagnetic materials, the amplitude of the voltages on the outputs 22 and 23 of the rectifier 2 are adjusted 2S through conkrol of the unit 4 so that the ratio amplitude of the positive pulses produced through the coil 7 to the nega-tive pulses produced through the coil 7' is 1,8; 0,2. Indeed the amplitude of the positive and negative magnetic field pulses can be varied through the amplitude of the voltages from the outputs 22 and 23 of the adjustable rectifier 2. Of course, the width of the positive and the negative magnetic field pulses can be adjusted through adjustment of the capacitive and inductive values of the capacitors 6 and 6' and of the coils 7 and 7'.
In operatlon, the direct current voltage on the rectifier output 22 charges the capacitor 6 when the thyristor 8 is in the off state. Accordingly, the direct 33~33 current voltage on the rectifier output 23 charges the capa-citor 6' when the thyristor 8 7 iS in -the off state. As soon as a con-trol pulse is applied on the control electrode 83 - th:rough the output 31 of the generator 3, the thyristor 8 becomes .in the on state and a current i flows in the loop Eormed by the thyristor 8, the coil 7 and the capacitor 6 to produce a positive magnetic field pulse through the coil 7. In the same manner, as soon as a control pulse is trans-mitted to the control electrode 86 through the output 32 of the generator 3, the thyristor 8' becomes in -the on state and the capacitor 6' discharges into the coil 7' through the thyristor 8' in order to produce a current i' into this coil 7' so as to generate a negative magnetic field pulse. As soon as the voltage between the anode and the cathode of each thyristor 8, 8' becomes negative, this thyristor is switched back into the off state.
It can therefore be easily appreciated that by controlling supplying of the control pulses through the outputs 31 and 32 of the generator 3, positive and negative magnetic field pulses can be consecutively produced through the coils 7 and 7'.
In order to improve the wear resistance of the treated ferromagnetic materials, the amplitude of the voltages on the outputs 22 and 23 of the rectifier 2 are adjusted 2S through conkrol of the unit 4 so that the ratio amplitude of the positive pulses produced through the coil 7 to the nega-tive pulses produced through the coil 7' is 1,8; 0,2. Indeed the amplitude of the positive and negative magnetic field pulses can be varied through the amplitude of the voltages from the outputs 22 and 23 of the adjustable rectifier 2. Of course, the width of the positive and the negative magnetic field pulses can be adjusted through adjustment of the capacitive and inductive values of the capacitors 6 and 6' and of the coils 7 and 7'.
3~3 Also in order to improve the wear resistance of the treated ferromagnetic materials, the control pulse generator 3 is controlled -through the unit 4 -to produce on its outputs 31 and 32 control pulses which causes magnetic field pulses oE one polarity to repeat with an equal or lower frequency compared to the repetition frequency of the magnetic field pulses of the other polarity.
At the end of the treatment, the control unit delivers through its output 43 to the rectifier 2 pulses which control the rectifier 2 so that the voltages on its outputs 22 and 23 gradually reduced to zero so as to gradually reduce to zero the amplitude of the positive and negative magnetic field pulses generated by the coils 7 and 7'. For -that purpose, the control unit 4 may comprise a program stored therein and which causes production of the latter pulses on its output ~3 at the end of a certain preset period of -time. Of course, the prograrn of -the control unit 4 can be modified at will depending on the type of ferromagne-tic materials to be treated.
Another important advantage of the device in accordance with the present invention is that after the treatment the ferromagnetic materials are completely dema-gnetized.
Although the present invention has been described hereinabove by way of a preferred embodiment thereof, it should be pointed out that any modification to this embodi-ment within the scope of the appended claims is not deemed to alter or change the nature and scope of the present inven-tion.
At the end of the treatment, the control unit delivers through its output 43 to the rectifier 2 pulses which control the rectifier 2 so that the voltages on its outputs 22 and 23 gradually reduced to zero so as to gradually reduce to zero the amplitude of the positive and negative magnetic field pulses generated by the coils 7 and 7'. For -that purpose, the control unit 4 may comprise a program stored therein and which causes production of the latter pulses on its output ~3 at the end of a certain preset period of -time. Of course, the prograrn of -the control unit 4 can be modified at will depending on the type of ferromagne-tic materials to be treated.
Another important advantage of the device in accordance with the present invention is that after the treatment the ferromagnetic materials are completely dema-gnetized.
Although the present invention has been described hereinabove by way of a preferred embodiment thereof, it should be pointed out that any modification to this embodi-ment within the scope of the appended claims is not deemed to alter or change the nature and scope of the present inven-tion.
Claims (6)
1. A method for treating ferromagnetic ma-terials with magnetic field pulses having preset repetition frequency, amplitude and width, said materials being dema-gnetized at the end of the treatment, wherein the magnetic field pulses include positive pulses and negative pulses, the amplitude ratio of the positive to the negative pulses is 1,8; 0,2, and the magnetic field pulses of one polarity repeat with an equal or lower frequency compared with the repetition frequency of the pulses of the other polarity.
2. A method according to claim 1, wherein the amplitude of the magnetic field pulses is gradually reduced to zero at the end of the treatment.
3. A device for treating ferromagnetic mate-rials with magnetic field pulses having preset repetition frequency, amplitude and width, said materials being dema-gnetized at the end of the treatment, said treating device comprising:
a magnetic field pulse generator comprising a first and a second generating units each including a capacitor and a coil interconnected in series, and a thyris-tor connected in parallel with the serially interconnected capacitor and coil, each thyristor being provided with an anode, a control electrode and a cathode connected to a reference voltage, said magnetic field pulses being generated through said coils and the coil of said first unit being connected to generate positive magnetic field pulses while the coil of said second unit is connected to generate nega-tive magnetic field pulses;
a controllable rectifier for applying a first voltage to the anode of the thyristor of said first generating unit, and for applying a second voltage to the anode of the thyristor of said second generating unit, the amplitude of said first and second voltages being adjusted so that the amplitude ratio of the positive to the negative magnetic field pulses is 1,8; 0,2;
control pulse generating means including a first output for delivering control pulses to the control elec-trode of the thyristor of said first generating unit, and a second output for delivering control pulses to the control electrode of the thyristor of said second generating unit, said control pulses controlling operation of said thyristors to cause production through said coils of magnetic field pulses of one polarity which repeat with an equal or lower frequency compared with the repetition frequency of the magnetic field pulses of the other polarity; and control means for controlling operation of said rectifier and said control pulse generating means.
a magnetic field pulse generator comprising a first and a second generating units each including a capacitor and a coil interconnected in series, and a thyris-tor connected in parallel with the serially interconnected capacitor and coil, each thyristor being provided with an anode, a control electrode and a cathode connected to a reference voltage, said magnetic field pulses being generated through said coils and the coil of said first unit being connected to generate positive magnetic field pulses while the coil of said second unit is connected to generate nega-tive magnetic field pulses;
a controllable rectifier for applying a first voltage to the anode of the thyristor of said first generating unit, and for applying a second voltage to the anode of the thyristor of said second generating unit, the amplitude of said first and second voltages being adjusted so that the amplitude ratio of the positive to the negative magnetic field pulses is 1,8; 0,2;
control pulse generating means including a first output for delivering control pulses to the control elec-trode of the thyristor of said first generating unit, and a second output for delivering control pulses to the control electrode of the thyristor of said second generating unit, said control pulses controlling operation of said thyristors to cause production through said coils of magnetic field pulses of one polarity which repeat with an equal or lower frequency compared with the repetition frequency of the magnetic field pulses of the other polarity; and control means for controlling operation of said rectifier and said control pulse generating means.
4. A device according to claim 3, wherein said control means comprise means for controlling said rectifier so as to gradually reduce the amplitude of the first and second voltages to zero at the end of the treatment.
5. A device according to claim 3, further comprising a current source for supplying electric energy to said control pulse generating means and said control means.
6. A device according to claim 3, wherein said control means comprise trigger means for producing an output signal in response to said magnetic field pulses, and a control unit for controlling said rectifier and said control pulse generating means in accordance with said output signal from the trigger means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BG8257551A BG38909A1 (en) | 1982-07-27 | 1982-07-27 | Method and device for acting on ferromagnetic materials |
| BG57551 | 1982-07-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1223303A true CA1223303A (en) | 1987-06-23 |
Family
ID=3911066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000433346A Expired CA1223303A (en) | 1982-07-27 | 1983-07-27 | Treating ferromagnetic materials to increase wear resistance |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0101922B1 (en) |
| JP (1) | JPS5972115A (en) |
| AT (1) | ATE17535T1 (en) |
| AU (2) | AU1722983A (en) |
| BG (1) | BG38909A1 (en) |
| CA (1) | CA1223303A (en) |
| CS (1) | CS256908B1 (en) |
| DE (1) | DE3361854D1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BG41281A1 (en) * | 1985-07-29 | 1987-05-15 | Makedonski | Device for magneto- impulse treatment of ferromagnetic materials |
| EP1513168B1 (en) * | 2003-09-02 | 2017-03-08 | Albert Maurer | Method and apparatus for magnetising a magnet system |
| US7868721B2 (en) * | 2008-04-04 | 2011-01-11 | Cedar Ridge Research, Llc | Field emission system and method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE790729A (en) * | 1971-11-19 | 1973-02-15 | Lenoir Raoul Ets | COIL EXCITATION CURRENT CONTROL DEVICE PRODUCING A MAGNETIC FLOW OF REVERSE POLARITY |
| CH582411A5 (en) * | 1975-03-03 | 1976-11-30 | Bbc Brown Boveri & Cie | |
| US4158873A (en) * | 1977-08-31 | 1979-06-19 | Magnaflux Corporation | Demagnetizing methods and apparatus |
| IT1119003B (en) * | 1979-06-25 | 1986-03-03 | Riv Officine Di Villar Perosa | DEMAGNETIZER DEVICE |
| DD146726A1 (en) * | 1979-10-22 | 1981-02-25 | Siegfried Wirthgen | METHOD FOR GENERATING DC CURRENT PULSES IN COILS OF ELECTROMAGNETS |
| IT1141165B (en) * | 1980-02-06 | 1986-10-01 | Sdm Sistemi & Dispositivi Magn | SYSTEM AND CIRCUIT PROVISION FOR THE DEMAGNETIZATION OF PERMANENT MAGNETS |
-
1982
- 1982-07-27 BG BG8257551A patent/BG38909A1/en unknown
-
1983
- 1983-07-22 AU AU17229/83A patent/AU1722983A/en not_active Abandoned
- 1983-07-25 EP EP83107298A patent/EP0101922B1/en not_active Expired
- 1983-07-25 DE DE8383107298T patent/DE3361854D1/en not_active Expired
- 1983-07-25 AT AT83107298T patent/ATE17535T1/en not_active IP Right Cessation
- 1983-07-26 CS CS835592A patent/CS256908B1/en unknown
- 1983-07-26 JP JP58135293A patent/JPS5972115A/en active Pending
- 1983-07-27 CA CA000433346A patent/CA1223303A/en not_active Expired
-
1988
- 1988-03-25 AU AU13773/88A patent/AU1377388A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5972115A (en) | 1984-04-24 |
| AU1722983A (en) | 1984-02-02 |
| ATE17535T1 (en) | 1986-02-15 |
| EP0101922B1 (en) | 1986-01-15 |
| EP0101922A1 (en) | 1984-03-07 |
| AU1377388A (en) | 1988-07-07 |
| BG38909A1 (en) | 1986-03-14 |
| CS256908B1 (en) | 1988-04-15 |
| DE3361854D1 (en) | 1986-02-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |