US3666919A - Casting oven - Google Patents
Casting oven Download PDFInfo
- Publication number
- US3666919A US3666919A US152519A US3666919DA US3666919A US 3666919 A US3666919 A US 3666919A US 152519 A US152519 A US 152519A US 3666919D A US3666919D A US 3666919DA US 3666919 A US3666919 A US 3666919A
- Authority
- US
- United States
- Prior art keywords
- crucible
- coil
- oven
- turntable
- aforesaid
- 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
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B17/00—Furnaces of a kind not covered by any preceding group
- F27B17/02—Furnaces of a kind not covered by any preceding group specially designed for laboratory use
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B14/00—Crucible or pot furnaces
- F27B14/06—Crucible or pot furnaces heated electrically, e.g. induction crucible furnaces with or without any other source of heat
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D99/00—Subject matter not provided for in other groups of this subclass
- F27D99/0001—Heating elements or systems
- F27D99/0006—Electric heating elements or system
- F27D2099/0008—Resistor heating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S164/00—Metal founding
- Y10S164/04—Dental
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S266/00—Metallurgical apparatus
- Y10S266/90—Metal melting furnaces, e.g. cupola type
Definitions
- the invention is concerned with an electrically energized casting oven of the crucible type, and one which may be used, for example, for melting precious metals at elevated temperatures of the order of 2,400" F.
- the oven of the invention includes a coil of resistance steel, or other appropriate resistance material, rather than carbon electrodes, as the heating element.
- the invention finds particular utility in the centrifugal casting of precious metals, such as gold, by the tilt method.
- a metal such as gold is placed in a crucible, and a lost wax flask mold is supported over the mouth of the crucible.
- the crucible is then heated to an elevated temperature to melt the gold, and the crucible and flask are then rotated on a turntable about a vertical axis.
- the crucible and flask are pivotally mounted on the turntable, and as the turntable is turned, they tilt and the molten gold from the crucible is forced by centrifugal force into the flask.
- the oven normally used in the prior art to heat the crucible generates its heat by passing an electric current between carbon electrodes.
- it is well known that such an oven is not too satisfactory, primarily because of the rapid deterioration of the carbon electrodes which necessitates their frequent replacement.
- the oven of the present invention is constructed to incorporate a coil of electrical resistance material, such as resistance steel, ceramic wire or the like.
- the coil may be formed, for example, of metal wire or ceramic elements such as are presently marketed by the Kanthal Corporation of Bethel, Connecticut.
- the elements may be formed to the desired helical shape, .for example, by passing highcurrent therethrough until the particular element becomes pliable, and by then winding the element about a cylindrical mandrel.
- temperatures of the order of 2,400 F. and higher may be achieved by passing a current of the order of 300 amperes through the helical element ata voltage. of, for example, 12 volts.
- Temperatures in excess of 3,000 F. may be achieved by the use of a helix element formed, for example, of Kanthal Super-Ceramic Wire.
- the apparatus of FIG. 1 includes, for example, a cabinet 10.
- Appropriate transformers, drive motors, and other operating components of the apparatus may be mounted within the cabinet.
- a power transformer for the apparatus may be housed within the cabinet, the transformer being capable, in a particular embodiment, for example, of converting 220 volts AC into l2-24 volts at secondary currents of the order of 300 amperes.
- a turntable 12 is rotatably mounted on the top of the cabinet 10, and the turntable may be driven by an electric motor 1 1. supported within the cabinet. When the motor is deenergized, the turntable 12 may be held at a particular angular position by means, for example, of a brake 14.
- a cylindrical casting oven 16, constructed in accordance with the concepts of the invention, is pivotally mounted on the turntable 12.
- a clamp 18 is mounted on top of the oven, and the clamp serves to hold a flask mold 20 in position over the mouth of a crucible supported within the oven.
- Electric energy for the oven 16 is supplied by electric cables 22 which connect the helical heating element 24 (FIG. 2) of the oven to the secondary of the transformer in the cabinet 10.
- a disconnect mechanism 26 is mounted on top of the cabinet, and this mechanism is operated by a disconnect lever 28.
- the disconnect 26 serves to connect the cables 22 to the transformer in the cabinet 10 so that current may pass through the heating element 24 to melt the metal in the crucible within the oven 16.
- the lever 28 is operated to cause the disconnect 26 todrsconnect the cables 22 so that the turntable 12 is free to rotate.
- the turntable 12 is then rotated rapidly by the motor I 1, and the oven 16 and flask 20 are tilted, as a unit, so as to assume a horizontal position.
- the oven and flask may be tilted, for example, by a hydraulic actuator 29.
- the gold in the crucible in the center of the oven 16 is then forced into the flask mold 20 by centrifugal action, so that it may be cast into any desired form.
- a counterweight 31 may be provided at the edge of the turntable 12, as shown.
- the oven 16, as shown in FIG. 2 includes a thin tubular metallic outer wall 50.
- a cable support 52 may be attached to the outer wall.
- the heating element 24 is wound as a helical coil which is supported by a tubular member 54 within the tubular outer wall 50.
- the tubular member 54 may be composed of pieces of appropriate electrical insulating, refractory material.
- the refractory pieces included members 54a which serve to support the helical heating element, and which project radially inwardly to insulate the crucible (not shown) from the element when it is supported in the oven.
- the annular space between the tubular member 54 and the tubular outer wall 50 may be filled, for example, with asbestos, or the like.
- the heating element may be composed of resistance wires or electrically conductive ceramic material, such as described above, so that temperatures in excess of 2,000 F.
- Electrodes 56 connect the cables 22 to the heating element.
- the invention provides, therefore, an improved casting oven which incorporates a rugged heating element, and one which is not subject to wear, and need not be replaced during the normal life of the equipment.
- Apparatus for casting precious metal, and the like including a cylindrical oven member forming a crucible for the metal; a helically wound coil of electrically resistance material surrounding the crucible and responding to electric current to produce elevated temperatures in excess of 2,000 F. in the crucible, thermally insulating material surrounding said heating coil and said crucible, and said oven member being pivotally mounted on a turntable to be tilted about a horizontal axis as the turntable is turned about a vertical axis.
- the apparatus defined in claim 1 which includes electnc tables extending from an energizing source to the aforesaid coil to energize the coil when the turntable is stationary, and disconnect means for disconnecting the aforesaid tables from the energizing source when the turntable is turned about the aforesaid vertical axis.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Clinical Laboratory Science (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
Abstract
The invention is concerned with an electrically energized casting oven of the crucible type, and one which may be used, for example, for melting precious metals at elevated temperatures of the order of 2,400* F. The oven of the invention includes a coil of resistance steel, or other appropriate resistance material, rather than carbon electrodes, as the heating element.
Description
United States Patent Thiel 151 3,666,919 1 51 May 30, 1972 CASTING OVEN [72] Inventor: Frank M. Thiel, 8828 National Boulevard,
Culver City, Calif. 90230 [22] Filed: June 14, 1971 21 A'ppl. No.1 152,519
219/421, 219/426, 219/521, 266/33 51 1111.0 ..F27b 14/00 58 Field ofSearch ,.219/406, 420, 421,424, 425, 219/426, 427, 434, 521, 536; 13/21, 22, 25; 266/33 [56] References Cited UNITED STATES PATENTS 1,145,455 2/1930 Seaborn ..219/421 2,525,882 10/1950 Ferguson ..13/21 2,708,710 5/1955 De Verter ..219/421 X 2,720,686 10/1955 Higgins et a1... ...2l9/421 UX 2,851,579 9/1958 Pfeifier.... .....219/421 X 2,907,861 10/1959 Melton ..219/521 3,179,731 4/1965 Cash et a1. ..13/21 X 3,430,032 2/1969 Morey ..219/433 Primary Examiner-Volodymyr Y. Mayewsky Attorney-Jessup 8c Beecher [57] ABSTRACT The invention is concerned with an electrically energized casting oven of the crucible type, and one which may be used, for example, for melting precious metals at elevated temperatures of the order of 2,400" F. The oven of the invention includes a coil of resistance steel, or other appropriate resistance material, rather than carbon electrodes, as the heating element.
5 Claims, 2 Drawing Figures BACKGROUND OF THE INVENTION The invention finds particular utility in the centrifugal casting of precious metals, such as gold, by the tilt method. In practicing such a method, a metal such as gold is placed in a crucible, and a lost wax flask mold is supported over the mouth of the crucible. The crucible is then heated to an elevated temperature to melt the gold, and the crucible and flask are then rotated on a turntable about a vertical axis. The crucible and flask are pivotally mounted on the turntable, and as the turntable is turned, they tilt and the molten gold from the crucible is forced by centrifugal force into the flask.
Because of the high temperatures involved, especially in casting precious metal, the oven normally used in the prior art to heat the crucible generates its heat by passing an electric current between carbon electrodes. However, it is well known that such an oven is not too satisfactory, primarily because of the rapid deterioration of the carbon electrodes which necessitates their frequent replacement.
The oven of the present invention, however, is constructed to incorporate a coil of electrical resistance material, such as resistance steel, ceramic wire or the like. The coil may be formed, for example, of metal wire or ceramic elements such as are presently marketed by the Kanthal Corporation of Bethel, Connecticut. The elements may be formed to the desired helical shape, .for example, by passing highcurrent therethrough until the particular element becomes pliable, and by then winding the element about a cylindrical mandrel. In operation, for example, temperatures of the order of 2,400 F. and higher may be achieved by passing a current of the order of 300 amperes through the helical element ata voltage. of, for example, 12 volts. Temperatures in excess of 3,000 F. may be achieved by the use of a helix element formed, for example, of Kanthal Super-Ceramic Wire.
BRIEF DESCRIPTION OF THE DRAWING DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The apparatus of FIG. 1 includes, for example, a cabinet 10. Appropriate transformers, drive motors, and other operating components of the apparatus may be mounted within the cabinet. For example, a power transformer for the apparatus may be housed within the cabinet, the transformer being capable, in a particular embodiment, for example, of converting 220 volts AC into l2-24 volts at secondary currents of the order of 300 amperes.
A turntable 12 is rotatably mounted on the top of the cabinet 10, and the turntable may be driven by an electric motor 1 1. supported within the cabinet. When the motor is deenergized, the turntable 12 may be held at a particular angular position by means, for example, of a brake 14. A cylindrical casting oven 16, constructed in accordance with the concepts of the invention, is pivotally mounted on the turntable 12. A clamp 18 is mounted on top of the oven, and the clamp serves to hold a flask mold 20 in position over the mouth of a crucible supported within the oven.
Electric energy for the oven 16 is supplied by electric cables 22 which connect the helical heating element 24 (FIG. 2) of the oven to the secondary of the transformer in the cabinet 10. A disconnect mechanism 26 is mounted on top of the cabinet, and this mechanism is operated by a disconnect lever 28.
When the turntable 12 is stationary, the disconnect 26 serves to connect the cables 22 to the transformer in the cabinet 10 so that current may pass through the heating element 24 to melt the metal in the crucible within the oven 16. When the metal is melted, the lever 28 is operated to cause the disconnect 26 todrsconnect the cables 22 so that the turntable 12 is free to rotate. The turntable 12 is then rotated rapidly by the motor I 1, and the oven 16 and flask 20 are tilted, as a unit, so as to assume a horizontal position. The oven and flask may be tilted, for example, by a hydraulic actuator 29. The gold in the crucible in the center of the oven 16 is then forced into the flask mold 20 by centrifugal action, so that it may be cast into any desired form. A counterweight 31 may be provided at the edge of the turntable 12, as shown. I
The oven 16, as shown in FIG. 2 includes a thin tubular metallic outer wall 50. A cable support 52 may be attached to the outer wall. The heating element 24 is wound as a helical coil which is supported by a tubular member 54 within the tubular outer wall 50. The tubular member 54 may be composed of pieces of appropriate electrical insulating, refractory material. The refractory pieces included members 54a which serve to support the helical heating element, and which project radially inwardly to insulate the crucible (not shown) from the element when it is supported in the oven. The annular space between the tubular member 54 and the tubular outer wall 50 may be filled, for example, with asbestos, or the like. The heating element may be composed of resistance wires or electrically conductive ceramic material, such as described above, so that temperatures in excess of 2,000 F.
may be achieved when an electric current of the order, for example, of 300 amperes is passed through the element. Electrodes 56 connect the cables 22 to the heating element.
The invention provides, therefore, an improved casting oven which incorporates a rugged heating element, and one which is not subject to wear, and need not be replaced during the normal life of the equipment. I
While a particular embodiment of the invention has been shown and described, modifications may be made. It is intended in the following claimsto cover all modifications which fall within the scope of the invention.
What is claimed is:
1. Apparatus for casting precious metal, and the like, including a cylindrical oven member forming a crucible for the metal; a helically wound coil of electrically resistance material surrounding the crucible and responding to electric current to produce elevated temperatures in excess of 2,000 F. in the crucible, thermally insulating material surrounding said heating coil and said crucible, and said oven member being pivotally mounted on a turntable to be tilted about a horizontal axis as the turntable is turned about a vertical axis.
2. The apparatus defined in claim 1, in which the coil is formed of resistance steel.
3. The apparatus defined in claim 1, in which the coil is formed of a ceramic material.
4. The apparatus defined in claim 1, and which includes a clamp affixed to the top of the aforesaid oven to mount a flask mold over the crucible.
5. The apparatus defined in claim 1, and which includes electnc tables extending from an energizing source to the aforesaid coil to energize the coil when the turntable is stationary, and disconnect means for disconnecting the aforesaid tables from the energizing source when the turntable is turned about the aforesaid vertical axis.
Claims (5)
1. Apparatus for casting precious metal, and the like, including a cylindrical oven member forming a crucible for the metal; a helically wound coil of electrically resistance material surrounding the crucible and responding to electric current to produce elevated temperatures in excess of 2,000* F. in the crucible, thermally insulating material surrounding said heating coil and said crucible, and said oven member being pivotally mounted on a turntable to be tilted about a horizontal axis as the turntable is turned about a vertical axis.
2. The apparatus defined in claim 1, in which the coil is formed of resistance steel.
3. The apparatus defined in claim 1, in which the coil is formed of a ceramic material.
4. The apparatus defined in claim 1, and which includes a clamp affixed to tHe top of the aforesaid oven to mount a flask mold over the crucible.
5. The apparatus defined in claim 1, and which includes electric tables extending from an energizing source to the aforesaid coil to energize the coil when the turntable is stationary, and disconnect means for disconnecting the aforesaid tables from the energizing source when the turntable is turned about the aforesaid vertical axis.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15251971A | 1971-06-14 | 1971-06-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3666919A true US3666919A (en) | 1972-05-30 |
Family
ID=22543270
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US152519A Expired - Lifetime US3666919A (en) | 1971-06-14 | 1971-06-14 | Casting oven |
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Country | Link |
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US (1) | US3666919A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3818974A (en) * | 1971-06-28 | 1974-06-25 | O Eberle | Centrifugal vacuum casting apparatus |
US3977462A (en) * | 1974-05-20 | 1976-08-31 | Isao Ohara | Apparatus for producing a die cast of a complicated shape |
US4687044A (en) * | 1985-05-03 | 1987-08-18 | Tam Ceramics, Inc. | Injection method and apparatus |
CN104353922A (en) * | 2014-10-28 | 2015-02-18 | 国家电网公司 | Electrothermal tin melting device, manufacturing method of device and tin stamping method using device |
CN107262692A (en) * | 2017-06-29 | 2017-10-20 | 马鞍山市兴隆铸造有限公司 | Casting boiler centrifugal casting detection casting device |
CN107262693A (en) * | 2017-06-29 | 2017-10-20 | 马鞍山市兴隆铸造有限公司 | The smooth casting of pressure adjustable casting is dust-proof to make stove |
CN107321966A (en) * | 2017-06-29 | 2017-11-07 | 马鞍山市兴隆铸造有限公司 | The continuous cutting foundry furnace of tubulose casting ingot |
CN107321960A (en) * | 2017-06-29 | 2017-11-07 | 马鞍山市兴隆铸造有限公司 | Casting vacuum casting, which is quickly removed, uses foundry furnace |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1745455A (en) * | 1928-09-25 | 1930-02-04 | Lenell R Seaborn | Soldering ladle |
US2525882A (en) * | 1949-05-14 | 1950-10-17 | Loftus Engineering Corp | Electric ladle furnace |
US2708710A (en) * | 1951-03-27 | 1955-05-17 | Verter Walton G De | Soldering pot |
US2720686A (en) * | 1952-09-12 | 1955-10-18 | Gen Dynamics Corp | Die casting apparatus |
US2851579A (en) * | 1955-04-04 | 1958-09-09 | Western Electric Co | Resistance heated solder pot |
US2907861A (en) * | 1957-11-25 | 1959-10-06 | William L Melton | Electrical oil heating device |
US3179731A (en) * | 1963-04-17 | 1965-04-20 | Burns A Cash | Support means for resistance furnace |
US3430032A (en) * | 1965-11-10 | 1969-02-25 | Templeton Coal Co | Microflask heating device |
-
1971
- 1971-06-14 US US152519A patent/US3666919A/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1745455A (en) * | 1928-09-25 | 1930-02-04 | Lenell R Seaborn | Soldering ladle |
US2525882A (en) * | 1949-05-14 | 1950-10-17 | Loftus Engineering Corp | Electric ladle furnace |
US2708710A (en) * | 1951-03-27 | 1955-05-17 | Verter Walton G De | Soldering pot |
US2720686A (en) * | 1952-09-12 | 1955-10-18 | Gen Dynamics Corp | Die casting apparatus |
US2851579A (en) * | 1955-04-04 | 1958-09-09 | Western Electric Co | Resistance heated solder pot |
US2907861A (en) * | 1957-11-25 | 1959-10-06 | William L Melton | Electrical oil heating device |
US3179731A (en) * | 1963-04-17 | 1965-04-20 | Burns A Cash | Support means for resistance furnace |
US3430032A (en) * | 1965-11-10 | 1969-02-25 | Templeton Coal Co | Microflask heating device |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3818974A (en) * | 1971-06-28 | 1974-06-25 | O Eberle | Centrifugal vacuum casting apparatus |
US3977462A (en) * | 1974-05-20 | 1976-08-31 | Isao Ohara | Apparatus for producing a die cast of a complicated shape |
US4687044A (en) * | 1985-05-03 | 1987-08-18 | Tam Ceramics, Inc. | Injection method and apparatus |
CN104353922A (en) * | 2014-10-28 | 2015-02-18 | 国家电网公司 | Electrothermal tin melting device, manufacturing method of device and tin stamping method using device |
CN107262692A (en) * | 2017-06-29 | 2017-10-20 | 马鞍山市兴隆铸造有限公司 | Casting boiler centrifugal casting detection casting device |
CN107262693A (en) * | 2017-06-29 | 2017-10-20 | 马鞍山市兴隆铸造有限公司 | The smooth casting of pressure adjustable casting is dust-proof to make stove |
CN107321966A (en) * | 2017-06-29 | 2017-11-07 | 马鞍山市兴隆铸造有限公司 | The continuous cutting foundry furnace of tubulose casting ingot |
CN107321960A (en) * | 2017-06-29 | 2017-11-07 | 马鞍山市兴隆铸造有限公司 | Casting vacuum casting, which is quickly removed, uses foundry furnace |
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