US4101760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractory granular embedding composition for electric heating coils
Assignee: Eichenauer Heizelemente GmbH and Co KG
•
Filing: 1976-04-05
•
Granted: 1978-07-18
•
Expires: 1996-04-05
Abstract
Abstract A refractory, granular electrically insulative composition useful as an embedding composition for electric heating coils comprises fused and granulated, possibly ground, difficultly fusible, ceramic and possibly oxide-ceramic material having polyalkylsiloxane, e.g. polymethylsiloxane, or polyarylsiloxane admixed in a proportion of from 0.5 to 5.0% added weight. Use of the composition is suitable with tubular heaters which have been produced with it and which, after manufacture and before being brought into use, have been subjected to a heat treatment at a temperature of at least 65° C, for a period of at least 10 minutes. An electrical heating element comprises a housing which is embedded in the composition wherein the ceramic and possibly oxide-ceramic material has been ground.
Inventors
- 👤 Hanno Roller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:34
CPC Classifications
C; C04; C04B; C04B26/00; C04B26/30; H; H05; H05B; H05B3/00; H05B3/10; H05B3/18; H01; H01B; H01B3/00; H01B3/02; H01B3/025; H05B3/40; H05B3/42; H05B3/48; H05B3/52
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
56 words
A refractory, granular, electrically-insulative composition suitable for use as an embedding composition for electric heating coils, which composition comprises fused and granulated, high-melting, ceramic material having solid granulated polyalkylsiloxane or polyarylsiloxane admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the weight of the ceramic material.
Claim 2
Dependent Claim
56 words
A refractory, granular, electrically-insulative composition suitable for use as an embedding composition for electric heating coils, which composition comprises fused and granulated, high-melting, ceramic material having solid granulated polyalkylsiloxane or polyarylsiloxane admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the weight of the ceramic material.
Claim 3
Dependent Claim
13 words
A composition according to claim 1 wherein said ceramic material comprises oxide-ceramic material.
Claim 4
Dependent Claim
15 words
A composition according to claim 2, wherein the oxide-ceramic material is a high-melting metal oxide.
Claim 5
Dependent Claim
25 words
A composition according to claim 3, wherein the high-melting metal oxide is magnesium oxide, beryllium oxide, titanium dioxide, or silicon dioxide, or a mixture thereof.
Claim 6
Dependent Claim
14 words
A composition according to claim 4 wherein the high-melting metal oxide is magnesium oxide.
Claim 7
Dependent Claim
13 words
A composition according to claim 1, wherein the ceramic material has been ground.
Claim 8
Dependent Claim
11 words
A composition according to claim 1, wherein the polyalkylsiloxane comprises polymethylsiloxane.
Claim 9
Dependent Claim
65 words
A refractory, granular, electrically-insulative composition suitable for use as an embedding composition for electric heating coils, which composition comprises fused and granulated, high-melting, ceramic material having solid granulated polymethylsiloxane having a grain size of from 20 μ to 200 μ admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the weight of the ceramic material.
Claim 10
Dependent Claim
65 words
A refractory, granular, electrically-insulative composition suitable for use as an embedding composition for electric heating coils, which composition comprises fused and granulated, high-melting, ceramic material having solid granulated polymethylsiloxane having a grain size of from 20 μ to 200 μ admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the weight of the ceramic material.
Claim 11
Dependent Claim
15 words
A composition according to claim 8, wherein the ceramic material comprises a silicate ceramic material.
Claim 12
Dependent Claim
13 words
A composition according to claim 8 wherein the ceramic material comprises magnesium oxide.
Claim 13
Independent Claim
97 words
A method of using a refractory, granular, electrically-insulative composition as an embedding composition for an electric heating coil in a tubular heater, which composition comprises fused and granulated, high-melting ceramic material having solid granulated polyalkylsiloxane or polyarylsiloxane admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the total weight of the ceramic material comprising subjecting said tubular heater containing said electric heating coil embedded in said composition to a heat treatment at a temperature of at least 65° C, for a period of at least 10 minutes.
Claim 14
Independent Claim
97 words
A method of using a refractory, granular, electrically-insulative composition as an embedding composition for an electric heating coil in a tubular heater, which composition comprises fused and granulated, high-melting ceramic material having solid granulated polyalkylsiloxane or polyarylsiloxane admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the total weight of the ceramic material comprising subjecting said tubular heater containing said electric heating coil embedded in said composition to a heat treatment at a temperature of at least 65° C, for a period of at least 10 minutes.
Claim 15
Independent Claim
103 words
A method of using a refractory, granular, electrically-insulative composition as an embedding composition for an electric heating coil in a tubular heater, which composition comprises fused and granulated, high-melting magnesium oxide having solid granulated polymethylsiloxane having a grain size of from 20μ to 200μ admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the total weight of magnesium oxide comprising subjecting said tubular heater containing said electric heating coil embedded in said composition to a heat treatment at a temperature of at least 65° C, for a period of at least 10 minutes.
Claim 16
Independent Claim
103 words
A method of using a refractory, granular, electrically-insulative composition as an embedding composition for an electric heating coil in a tubular heater, which composition comprises fused and granulated, high-melting magnesium oxide having solid granulated polymethylsiloxane having a grain size of from 20μ to 200μ admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the total weight of magnesium oxide comprising subjecting said tubular heater containing said electric heating coil embedded in said composition to a heat treatment at a temperature of at least 65° C, for a period of at least 10 minutes.
Claim 17
Dependent Claim
66 words
An electrical heating element comprising a housing and an electric heating coil which is embedded in a refractory, granular, electrically-insulative composition contained within said housing which composition comprises fused and granulated, high-melting, ceramic material having solid granulated polyalkylsiloxane or polyarylsiloxane admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the total weight of the ceramic material.
Claim 18
Dependent Claim
66 words
An electrical heating element comprising a housing and an electric heating coil which is embedded in a refractory, granular, electrically-insulative composition contained within said housing which composition comprises fused and granulated, high-melting, ceramic material having solid granulated polyalkylsiloxane or polyarylsiloxane admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the total weight of the ceramic material.
Claim 19
Dependent Claim
30 words
An electrical heating element according to claim 3 wherein said polyalkylsiloxane is a polymethylsiloxane having a grain size of from 20μ to 200μ and said ceramic material is magnesium oxide.
Claim 20
Dependent Claim
67 words
A refractory, granular electrically insulative composition suitable for use as an embedding composition for electric heating coils, which composition consists essentially of fused and granulated, high-melting magnesium oxide having a solid granulated polymethylsiloxane with a grain size of from 20μ to 200μ admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the weight of the magnesium oxide.
Claim 21
Dependent Claim
67 words
A refractory, granular electrically insulative composition suitable for use as an embedding composition for electric heating coils, which composition consists essentially of fused and granulated, high-melting magnesium oxide having a solid granulated polymethylsiloxane with a grain size of from 20μ to 200μ admixed therewith in a proportion of from 0.5 to 5.0% by weight, expressed as an added weight, based on the weight of the magnesium oxide.
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) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |