Patent US3780200A successfully refreshed from Google Patents.
US3780200A
Expired / Lapsed
US
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Heating apparatus for plastic extruders
Assignee: Tesla AS
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Filing: 1971-11-18
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Granted: 1973-12-18
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Expires: 1991-11-18
Abstract
Abstract A heating unit comprising a chamber in which are located at least two electrodes. The electrodes each comprising a first portion matching and secured to the interior wall of the chamber and a second portion extending radially inward toward the central axis.
Inventors
- 👤 K Maurer
- 👤 L Benda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:59
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/02; H05B3/03; H05B3/60
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
105 words
In an extruder for clay, ceramic and the like materials, heating apparatus comprising a heating chamber formed from a hollow body having a central axis and an insulated interior surface, and at least two electrodes located within said body and connected to a source of current, each of said electrodes comprising an elongated internal and external portion extending parallel to the central axis conductively connected with each other to form a unitary member, the external portion being insulatingly secured to the interior surface of said body and the internal portion spaced from said surface and extending radially inward toward the central axis of said body.
Claim 2
Dependent Claim
105 words
In an extruder for clay, ceramic and the like materials, heating apparatus comprising a heating chamber formed from a hollow body having a central axis and an insulated interior surface, and at least two electrodes located within said body and connected to a source of current, each of said electrodes comprising an elongated internal and external portion extending parallel to the central axis conductively connected with each other to form a unitary member, the external portion being insulatingly secured to the interior surface of said body and the internal portion spaced from said surface and extending radially inward toward the central axis of said body.
Claim 3
Dependent Claim
27 words
The apparatus according to claim 1, wherein the internal portion of the electrode has the form of a rib connected to the external portion of the electrode.
Claim 4
Dependent Claim
49 words
The apparatus according to claim 1, wherein the internal portion of the electrode has the shape of an elongated plate or strip, the longitudinal direction of the latter being parallel with the axis of the body and being connected to the external one by means of a radial strut.
Claim 5
Dependent Claim
23 words
The apparatus according to claim 1 wherein the cross section transverse to longitudinal direction of the internal portion of the electrode is curved.
Claim 6
Dependent Claim
25 words
The apparatus according to claim 1, wherein the cross section transverse to longitudinal direction of the internal portion of the electrode is an inverted V-shape.
Claim 7
Dependent Claim
41 words
The apparatus according to claim 1, wherein the shape of the external part of the electrode is matched to the shape of that part of the internal surface of the body at which the external part of the electrode is located.
Claim 8
Dependent Claim
21 words
The apparatus according to claim 1, wherein the external part and internal portion of the electrode are made of one piece.
Claim 9
Dependent Claim
33 words
The apparatus according to claim 1, wherein the surface of the internal portion of the electrode is at least equal to a fifth of the surface of the external portion of the electrode.
Claim 10
Dependent Claim
48 words
The apparatus according to claim 1, wherein the width of the electrodes in the direction of the central axis is varied in dependence on the change of the electrical resistance of the plastic mass as a result of change of temperature in its passage through the heating chamber.
Claim 11
Dependent Claim
33 words
The apparatus according to claim 1, wherein the internal portion of the electrode penetrates into the depth of at least one third of the radius of the body, measured from the internal surface.
Claim 12
Dependent Claim
19 words
The apparatus according to claim 1, wherein the electrodes are connected in delta to a three phase current source.
Claim 13
Dependent Claim
47 words
The apparatus according to claim 1, wherein the electrodes are connected in wye to a three phase current source, and a conductive mandrel is located to extend along the central axis of the body, said mandrel being connected to the node of the three phase current source.
Claim 14
Dependent Claim
17 words
The apparatus according to claim 12, wherin the conductive mandrel extends through the body to its orifice.
References Cited (Backward Citations)
US2817695A
Cited
US3335460A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |