Patent US4238635A successfully refreshed from Google Patents.
US4238635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Melting and casting means
Assignee: Individual
•
Filing: 1979-09-24
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Granted: 1980-12-09
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Expires: 1999-09-24
Abstract
Abstract The invention concerns a melting and casting means. The means comprises a heating chamber confined by side, top and bottom walls made of insulating material and enclosed by a steel shell. Mounted in the chamber are a crucible stand and upon said stand a crucible. According to the invention, the means further comprises at least three silicon carbide heating elements for heating the crucible to between 1100° and 1650° C. to the purpose of melting copper and copper alloys, and the insulating material mainly consists of aluminium oxide and silicon oxide fibres. The heating elements have been disposed in the chamber so that the distance between the element center and the outer wall of the crucible is 2 to 4 times the element diameter. The elements are advantageously disposed horizontally piercing the side walls of the means, and they have no contact with the bottom wall. The spacing of the heating elements from the inner wall of the chamber is advantageously 2 to 4 times the element diameter. The thermal conductivity of the thermally insulating material is about 0.1-0.3 kcal/m h °C. at 400° C. and respectively 1200° C.
Inventors
- 👤 Matti Saarivirta
- 👤 Kalervo Lahtinen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:29
CPC Classifications
F; F27; F27B; F27B14/00; F27B14/08; F27B14/10; F27B14/12; F27B14/06; F27B14/061; F27D; F27D1/00; F27D11/00; F27D11/02; F27B2014/0843; F27D99/00; F27D99/0001; F27D99/0006; F27D2099/0008; F27D2099/0011
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
184 words
A melting and casting apparatus, comprising a heating chamber (20) with side walls (1), a top wall (2), a bottom wall (3) all made of well heat-insulating material (4), a steel shell (5) encircling said heating chamber; a crucible stand (6) disposed within said chamber; a crucible (7) placed on said stand; a minimum of three heating elements (8) installed in said chamber and provided with electric leads (19), said heating elements being disposed within said chamber between said heating elements and said crucible without any physical contact between said heating elements and said crucible; characteristized in that the heating elements (8) are silicon carbide heating elements for heating the crucible to a temperature between 1100 and 1650 degrees Centrigrade for the melting of copper and copper alloys, the well heat-insulating material (4) consists mainly of aluminium oxide and silicon oxide fibres, and the heating elements are so located in the heating chamber that the distance from the centre of the elements to the outer surface (9) of the crucible is 2-4 times 1, where 1 stands for the diameter of the heating element.
Claim 2
Dependent Claim
184 words
A melting and casting apparatus, comprising a heating chamber (20) with side walls (1), a top wall (2), a bottom wall (3) all made of well heat-insulating material (4), a steel shell (5) encircling said heating chamber; a crucible stand (6) disposed within said chamber; a crucible (7) placed on said stand; a minimum of three heating elements (8) installed in said chamber and provided with electric leads (19), said heating elements being disposed within said chamber between said heating elements and said crucible without any physical contact between said heating elements and said crucible; characteristized in that the heating elements (8) are silicon carbide heating elements for heating the crucible to a temperature between 1100 and 1650 degrees Centrigrade for the melting of copper and copper alloys, the well heat-insulating material (4) consists mainly of aluminium oxide and silicon oxide fibres, and the heating elements are so located in the heating chamber that the distance from the centre of the elements to the outer surface (9) of the crucible is 2-4 times 1, where 1 stands for the diameter of the heating element.
Claim 3
Dependent Claim
43 words
Apparatus according to claim 1, characterized in that the spacing of the heating element (8) from the inner wall (10) of the heating chamber (20) parallelling the heating element is 2-4 times 1, where 1 refers to the diameter of the heating element.
Claim 4
Dependent Claim
40 words
Apparatus according to claim 1, characterized in that a packing (21) has been mounted between the mouth of the crucible (7) opening upwards and the top wall (2) for preventing the release of metal vapours into the heating chamber 20.
Claim 5
Dependent Claim
95 words
Apparatus according to claim 1, characterized in that the heating chamber (20) has substantially the shape of an elongated parallelepipedon in which the crucible has been substantially centrally placed, that the heating elements (8) pierce the opposite, longer walls (10) of the chamber, parallelling the shorter walls (10), and are located above each other in two vertical rows on either side of the crucible between the shorter walls of the chamber and the crucible, the distance of the centerlines of the elements from the outer surface of the crucible being 2.3-3.5 times the element diameter.
Claim 6
Dependent Claim
33 words
Melting and casting apparatus according to claim 4, characterized in that the distance of the centerlines of the elements from the shorter walls of the chamber (20) is 2-3 times the element diameter.
Claim 7
Dependent Claim
35 words
Melting and casting apparatus according to claim 4, characterized in that the distance of the centerlines of the lowermost elements (8) from the bottom (3) of the chamber (20) is 3-5 times the element diameter.
Claim 8
Dependent Claim
40 words
Melting and casting apparatus according to claim 4, characterized in that the distance of the centerline of each element (8) from the centerline of the element which is closest in vertical direction is 2-4 times the diameter of the element.
Claim 9
Dependent Claim
42 words
Apparatus according to claim 1, characterized in that the thermal conductivity of the fibrous insulating material (4) is 0.1-0.3 kcal/mh° C. in the outer layer and correspondingly in the inner layer of the insulating material at 400° C. and correspondingly 1200° C.
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) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |