US2351056A - Electric conductor - Google Patents
Electric conductor Download PDFInfo
- Publication number
- US2351056A US2351056A US258571A US25857139A US2351056A US 2351056 A US2351056 A US 2351056A US 258571 A US258571 A US 258571A US 25857139 A US25857139 A US 25857139A US 2351056 A US2351056 A US 2351056A
- Authority
- US
- United States
- Prior art keywords
- insulating material
- insulating
- conductor
- calcium oxide
- electric conductor
- 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 - Lifetime
Links
- 239000004020 conductor Substances 0.000 title description 27
- 239000011810 insulating material Substances 0.000 description 28
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 22
- 235000012255 calcium oxide Nutrition 0.000 description 15
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 14
- 239000000292 calcium oxide Substances 0.000 description 14
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 14
- 239000000395 magnesium oxide Substances 0.000 description 14
- 239000000203 mixture Substances 0.000 description 9
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 229910011255 B2O3 Inorganic materials 0.000 description 4
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000018044 dehydration Effects 0.000 description 3
- 238000006297 dehydration reaction Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000008240 homogeneous mixture Substances 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 235000010755 mineral Nutrition 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 229910052810 boron oxide Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 1
- GPUADMRJQVPIAS-QCVDVZFFSA-M cerivastatin sodium Chemical compound [Na+].COCC1=C(C(C)C)N=C(C(C)C)C(\C=C\[C@@H](O)C[C@@H](O)CC([O-])=O)=C1C1=CC=C(F)C=C1 GPUADMRJQVPIAS-QCVDVZFFSA-M 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/40—Heating elements having the shape of rods or tubes
- H05B3/42—Heating elements having the shape of rods or tubes non-flexible
- H05B3/48—Heating elements having the shape of rods or tubes non-flexible heating conductor embedded in insulating material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/16—Rigid-tube cables
Definitions
- the present invention relates to the manufacture of electric conductors composed of one or a plurality of singleor divided conducting or resistant cores which are insulated from a metal sheath by a powdered mineral insulating material.
- the insulating material usually employed hitherto in such cables is ordinary magnesium oxide.
- said value is about 100,000 ohms when the radial thickness of the insulating material is 1.5 mm. and in the above circumstances of exposure.
- the conductor is cut at a certain length, for example at a few centimetres, from-each of the ends of the section. substantially the initial value of insulating resistance is found again.
- the variation of insulating resistance observed is an end phenomenon and, independently of the insulating resistance per kilometre of the conductor itself or of the lineformed by same, it is possible to define a "limiting insulating resistance per free en In the above mentioned case.
- the mean value of the lim ting insulating resistance per free end is about'200.000 ohms.
- the decrease of the insulating resistance may be considerable, in particular when the insulating material is ordinary magnesium oxide.
- the drawing illustrates a cross-section of a conductor made in accordance with this invention.
- insulating materials are employed such that the conductors manufactured have a higher limiting insulating resist ance per free end than that obtained with ordinary magnesium oxide, i. 'e. higher than 0.2 megohm for a radial thickness of insulating material of 1.5 mm.
- the insulating material may be so chosen that the absolute value of the limiting insulating resistance of the line itself is higher than a predetermined value taking into account the number of free ends.
- oxides or compounds of calcium or of other similar substances will be chosen in particular.
- the limiting insulating resistance per end was found to be higher than 20 megohms, for a radial thickness of insulating material of 1.5 mm.
- Powdered insulating materials which are capable of swelling are generally suitable for this purpose, that is to say those, such as calcium oxides or compounds, which cannot absorb moisture or in a general manner combine with air or its constituents without increasing in volume.
- the insulating material is, in fact, bound by the owing to a natural action such as that of the carbonic acid of the air, are also suitable.
- the powdered insulating material used is totally dehydrated before the usual mechanical treatments of shaping, drawing, etc., theinsulating material being introduced into the rough shape, either in the powdered state, or in the shape of agglomerated blocks in a highly compact state, or in any other shape, or by means of any other methods. It is possible, in particular, to effect the total dehydration by heating the insulating material under appropriate conditions until it no longer loses weight; in practice, for ordinary calcium exide, such dehydration is complete when it has been subjected to a temperature of 900 to 1000 C. for several hours.
- the invention also covers the use of insulating materials having the properties claimed, and in particular calcium oxide, either in the state of homogeneous mixtures, or by radial or longitudinal juxtaposition of different insulating mate rials in contact with each other.
- Theinvention covers in particular th wires, cables or conductors of the category in question which have the properties described and in which the dielectric is binary and is formed by calcium oxide and magnesium oxide, whatever be the proportion of the two substances. The applicant ha proved. that in this. case, the highest limiting insulation resistance is obtained when the proportion of.
- the improvedinsulating material such as calcium oxide, boron oxide or the like may 7 be introduced into the homogeneous ,powdered insulating material only in th zone of each end -of--t he conductor.
- the invention also covers above.
- the conductors may be manufactured as above set forth and using for example at least for those portions adjacent the ends a mixture containing from 25 to 40% calcium oxide and 75 to 60% of magnesia. Thereafter each of the ends of the conductor may be dipped in' a boric acid solution.
- An electric conductor comprising a core; a
- An electric conductor comprising a ,core, a metallic sheath and a powdered insulating material located'b'etween. said core andsheath, said insulating material comprising a mixture of calcium oxide, magnesia and boric oxide, said calcium oxide comprising between 25 and 40% and said boric oxide comprising about 1% of. said mixture and said magnesia the remainder of 'said mixture.
- An electric conductor comprising a a core, a metallic sheath and a powdered insulating material located between said core and sheath, said insulating material located at the ends'of' said conductor comprising a mixture of about 25 to 40% of calcium oxide and to 60% of magnesia.
- An electric conductor comprising a. core, a metallic sheath and a powdered insulating material located between said core and sheath, said insulating material comprising a mixture :of about 25 to 40% 'of calcium oxide, 74" to 59% of magnesia and 1% of boric oxide.
Landscapes
- Inorganic Insulating Materials (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR160239X | 1939-02-16 | ||
FR843062T | 1939-02-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2351056A true US2351056A (en) | 1944-06-13 |
Family
ID=26213827
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US258571A Expired - Lifetime US2351056A (en) | 1939-02-16 | 1939-02-25 | Electric conductor |
Country Status (7)
Country | Link |
---|---|
US (1) | US2351056A (fr) |
BE (1) | BE432967A (fr) |
CH (1) | CH213329A (fr) |
DE (1) | DE882437C (fr) |
FR (1) | FR843062A (fr) |
GB (1) | GB528677A (fr) |
NL (1) | NL54441C (fr) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2890263A (en) * | 1952-11-18 | 1959-06-09 | Hackethal Draht & Kabelwerk Ag | Coaxial cables |
US3239784A (en) * | 1961-01-23 | 1966-03-08 | Schwartz Charles Aaron | Coil structure for a welding transformer |
US3909555A (en) * | 1974-10-16 | 1975-09-30 | Kaman Sciences Corp | Phase stable transmission cable with controlled thermal expansion characteristics |
US4085653A (en) * | 1976-09-15 | 1978-04-25 | General Electric Company | Ignition device |
DE3544801A1 (de) * | 1984-12-21 | 1986-06-26 | Philips Nv | Mit mineralischem isoliermittel abgeschirmtes kabel |
US5247158A (en) * | 1992-07-17 | 1993-09-21 | Watlow Electric Manufacturing Company | Electrical heater |
US6830374B1 (en) * | 1999-08-16 | 2004-12-14 | Temperature Management Systems (Proprietary) Limited | Metallurgical thermocouple |
US20110100667A1 (en) * | 2009-11-04 | 2011-05-05 | Peter Hardie | Audio cable with vibration reduction |
US11871486B2 (en) | 2017-02-01 | 2024-01-09 | Nvent Services Gmbh | Low smoke, zero halogen self-regulating heating cable |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4280932A (en) * | 1979-02-12 | 1981-07-28 | General Electric Company | Magnesia insulated heating elements |
DE8900876U1 (de) * | 1989-01-26 | 1989-08-10 | Siemens AG, 1000 Berlin und 8000 München | Heizelement |
-
0
- BE BE432967D patent/BE432967A/xx unknown
- NL NL54441D patent/NL54441C/xx active
- DE DENDAT882437D patent/DE882437C/de not_active Expired
-
1938
- 1938-03-02 FR FR843062D patent/FR843062A/fr not_active Expired
-
1939
- 1939-02-25 US US258571A patent/US2351056A/en not_active Expired - Lifetime
- 1939-02-27 CH CH213329D patent/CH213329A/fr unknown
- 1939-03-02 GB GB6829/39A patent/GB528677A/en not_active Expired
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2890263A (en) * | 1952-11-18 | 1959-06-09 | Hackethal Draht & Kabelwerk Ag | Coaxial cables |
US3239784A (en) * | 1961-01-23 | 1966-03-08 | Schwartz Charles Aaron | Coil structure for a welding transformer |
US3909555A (en) * | 1974-10-16 | 1975-09-30 | Kaman Sciences Corp | Phase stable transmission cable with controlled thermal expansion characteristics |
US4085653A (en) * | 1976-09-15 | 1978-04-25 | General Electric Company | Ignition device |
DE3544801A1 (de) * | 1984-12-21 | 1986-06-26 | Philips Nv | Mit mineralischem isoliermittel abgeschirmtes kabel |
US4689443A (en) * | 1984-12-21 | 1987-08-25 | U.S. Philips Corporation | Armored cable having mineral insulation |
US5247158A (en) * | 1992-07-17 | 1993-09-21 | Watlow Electric Manufacturing Company | Electrical heater |
US6830374B1 (en) * | 1999-08-16 | 2004-12-14 | Temperature Management Systems (Proprietary) Limited | Metallurgical thermocouple |
US20110100667A1 (en) * | 2009-11-04 | 2011-05-05 | Peter Hardie | Audio cable with vibration reduction |
US11871486B2 (en) | 2017-02-01 | 2024-01-09 | Nvent Services Gmbh | Low smoke, zero halogen self-regulating heating cable |
US11956865B2 (en) | 2017-02-01 | 2024-04-09 | Nvent Services Gmbh | Low smoke, zero halogen self-regulating heating cable |
Also Published As
Publication number | Publication date |
---|---|
GB528677A (en) | 1940-11-05 |
CH213329A (fr) | 1941-01-31 |
BE432967A (fr) | |
NL54441C (fr) | |
DE882437C (de) | 1953-05-28 |
FR843062A (fr) | 1939-06-26 |
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