US2045318A - Spark plug insulator - Google Patents
Spark plug insulator Download PDFInfo
- Publication number
- US2045318A US2045318A US724828A US72482834A US2045318A US 2045318 A US2045318 A US 2045318A US 724828 A US724828 A US 724828A US 72482834 A US72482834 A US 72482834A US 2045318 A US2045318 A US 2045318A
- Authority
- US
- United States
- Prior art keywords
- spark plug
- insulator
- corundum
- plug insulator
- weight
- 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
- 239000012212 insulator Substances 0.000 title description 15
- 239000011230 binding agent Substances 0.000 description 12
- 239000010431 corundum Substances 0.000 description 10
- 229910052593 corundum Inorganic materials 0.000 description 10
- 239000000463 material Substances 0.000 description 8
- 239000005995 Aluminium silicate Substances 0.000 description 4
- 235000012211 aluminium silicate Nutrition 0.000 description 4
- 239000010433 feldspar Substances 0.000 description 4
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- -1 for example Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000011214 refractory ceramic Substances 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 235000012222 talc Nutrition 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
- H01T13/38—Selection of materials for insulation
Definitions
- Sparking plug insulators must have not only great mechanical strength but also a great resistance to changes of temperature. More especially, the stresses which occur in the interior 5 of the sparking plug insulator due to the varying temperatures during the use of the sparking plug must be avoided as far as possible.
- Known highly refractory materials consisting of a single metallic oxide having a high fusing point, e. g. corundum, are therefore used for their manufacture.
- Such insulators are, however, very difiicult to manufacture, because they require very high burning temperatures which approximate to the fusing temperature of the corundum, and for which the customary tunnel kilns used for mass production are not suitable, and because it is almost impossible to avoid holes and other faults in the structure of the material.
- Highly refractory ceramic materials are also known, consisting of a metallic oxide as the base material and a clayey binder, so as to reduce the burning temperature and give a denser structure. It has hitherto been attempted to use such binders, the thermal expansion of which, in the non-plastic state, corresponds as far as possible to the thermal expansion of the base material, for example, corundum. Since, however the binder must also comply with other, and contradictory requirements, owing to the particular qualities demanded from the insulator, such as insulating capacity,
- the present invention avoids this disadvantage by employing a binding agent which is flexible or yielding relative to the base material.
- a binding agent having the above described qualities when used with corundum as the base material is, for example, a mixture of 32.7 parts by weight of steatite or talcum, 43.3 parts by weight of kaolin, and 24.0 parts by weight of feldspar, the mixture of corundum and binding agent being prepared, moulded and burnt by known methods to produce the finished article.
- a spark plug insulator made from corundum and a ceramic binding medium which becomes plastic at a temperature between 500 and 800 C. comprising steatite, kaolin and feldspar.
- a spark plug insulator made from corundum and a ceramic binding medium, comprising a mixture of .32.? parts by weight of steatite, 43.3 parts by weight of kaolin and 24.0 parts by weight of feldspar, which is flexible as compared with the corundum when the insulator is under stress due to heat expansion.
- a spark plug insulator made from corundum and a ceramic binding medium which becomes plastic at a temperature between 500 and 800 C. comprising a mixture of 32.7 parts by weight of steatite, 43.3 parts by weight of kaolin, and 24.0 parts by weight of feldspar.
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Description
Patented June 23, 1936 UNITED STATES PATENT OFFICE 2,045,318 SPARK PLUG INSULATOR Richard Stribeck, Stuttgart, Germany, assignor to Robert Bosch Aktiengesellschaft, Stuttgart,
Germany 3 Claims. (Cl. 10612) Sparking plug insulators must have not only great mechanical strength but also a great resistance to changes of temperature. More especially, the stresses which occur in the interior 5 of the sparking plug insulator due to the varying temperatures during the use of the sparking plug must be avoided as far as possible. Known highly refractory materials, consisting of a single metallic oxide having a high fusing point, e. g. corundum, are therefore used for their manufacture. Such insulators are, however, very difiicult to manufacture, because they require very high burning temperatures which approximate to the fusing temperature of the corundum, and for which the customary tunnel kilns used for mass production are not suitable, and because it is almost impossible to avoid holes and other faults in the structure of the material. Highly refractory ceramic materials are also known, consisting of a metallic oxide as the base material and a clayey binder, so as to reduce the burning temperature and give a denser structure. It has hitherto been attempted to use such binders, the thermal expansion of which, in the non-plastic state, corresponds as far as possible to the thermal expansion of the base material, for example, corundum. Since, however the binder must also comply with other, and contradictory requirements, owing to the particular qualities demanded from the insulator, such as insulating capacity,
greater or smaller differences between the thermal expansion coefiicient of the binder and that of the base material are unavoidable, which leads to internal stresses in the insulator and reduces its stability at changing temperatures.
The present invention avoids this disadvantage by employing a binding agent which is flexible or yielding relative to the base material.
In cases in which the thermal expansion of the base material greatly increases with increasing temperature, as for example, in the case of corundum, it may happen that the thermal expansion of the base material gradually exceeds the thermal expansion of the binding agent. In such cases, it is preferable to employ a binding agent which, in the finished insulator, begins to become plastic when approaching the critical temperature range. By "becoming plastic, not such a softening of the binder is of course, meant as would cause a deformation of the insulator and render it useless. The plasticity of the binder need only be such as to prevent the rise of the internal stresses in the insulator beyond a certain point. This plasticity of the binder very considerably improves the stability of the insulator at changing temperatures when it occurs even at comparatively low temperatures, say, between 500 and 800 C. A binding agent having the above described qualities when used with corundum as the base material, is, for example, a mixture of 32.7 parts by weight of steatite or talcum, 43.3 parts by weight of kaolin, and 24.0 parts by weight of feldspar, the mixture of corundum and binding agent being prepared, moulded and burnt by known methods to produce the finished article.
I declare that what I claim is:
1. A spark plug insulator made from corundum and a ceramic binding medium which becomes plastic at a temperature between 500 and 800 C. comprising steatite, kaolin and feldspar.
2. A spark plug insulator made from corundum and a ceramic binding medium, comprising a mixture of .32.? parts by weight of steatite, 43.3 parts by weight of kaolin and 24.0 parts by weight of feldspar, which is flexible as compared with the corundum when the insulator is under stress due to heat expansion.
3. A spark plug insulator made from corundum and a ceramic binding medium which becomes plastic at a temperature between 500 and 800 C. comprising a mixture of 32.7 parts by weight of steatite, 43.3 parts by weight of kaolin, and 24.0 parts by weight of feldspar.
RICHARD STRIBECK.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2045318X | 1933-05-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2045318A true US2045318A (en) | 1936-06-23 |
Family
ID=7982394
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US724828A Expired - Lifetime US2045318A (en) | 1933-05-15 | 1934-05-09 | Spark plug insulator |
Country Status (1)
Country | Link |
---|---|
US (1) | US2045318A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2898217A (en) * | 1956-08-06 | 1959-08-04 | Ohio Brass Co | Ceramic products |
US2917293A (en) * | 1955-10-28 | 1959-12-15 | Badger Mfg Company | Bubble tower and tunnel tray construction |
US3459567A (en) * | 1964-11-16 | 1969-08-05 | Ngk Insulators Ltd | Method for producing porcelain articles |
US3533812A (en) * | 1961-11-07 | 1970-10-13 | Interpace Corp | Process for the manufacture of ceramic articles,and product derived from such process |
-
1934
- 1934-05-09 US US724828A patent/US2045318A/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2917293A (en) * | 1955-10-28 | 1959-12-15 | Badger Mfg Company | Bubble tower and tunnel tray construction |
US2898217A (en) * | 1956-08-06 | 1959-08-04 | Ohio Brass Co | Ceramic products |
US3533812A (en) * | 1961-11-07 | 1970-10-13 | Interpace Corp | Process for the manufacture of ceramic articles,and product derived from such process |
US3459567A (en) * | 1964-11-16 | 1969-08-05 | Ngk Insulators Ltd | Method for producing porcelain articles |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2165819A (en) | Electric insulator and method of making same | |
US2308115A (en) | Ceramic body and method of making | |
US2045318A (en) | Spark plug insulator | |
US2272618A (en) | Ceramic body | |
US1458724A (en) | Refractory composition | |
US2157100A (en) | Glazed ceramic insulator and the like | |
US2152656A (en) | Insulator for spark plugs | |
US2867888A (en) | Method of firing alumina ceramics | |
US2120338A (en) | Spark plug insulator | |
US2308092A (en) | Ceramic composition and article made therefrom | |
US1938674A (en) | Resistance device and insulator | |
US2218584A (en) | Ceramic body | |
US2177943A (en) | Ceramic body for spark plug insulators | |
US2332014A (en) | Spark plug insulator | |
US2494277A (en) | Ceramic body and batch for making | |
US2272038A (en) | Heat conducting refractory materials | |
US2576380A (en) | Ceramic dielectrics comprising essentially titania | |
US2975145A (en) | Semi-conductive ceramic composition | |
US1572730A (en) | Batch for making ceramic material and to alpha ceramic material made therefrom | |
US2231024A (en) | Calcium oxide-chromium oxide refractory | |
US2214931A (en) | Ceramic body for spark plug insulators | |
US1438598A (en) | Ceramic insulating material | |
US2272039A (en) | Refractory composition | |
US2571526A (en) | Ceramic composition | |
US1862974A (en) | Ceramic wares and method of manufacture |