Title:
Control pin and spout system for heating metal casting distribution spout configurations
Kind Code:
A1


Abstract:
A control pin system, including an apparatus and method, for use in controlling the flow of molten metal in a molten metal distribution system for casting, with some aspects of the control pin including: a control pin body with an internal cavity and an outer surface, wherein the outer surface is sized and configured to operatively interact with an internal surface of a spout to effectively control the flow of molten metal through a spout aperture; and a heater element within the internal cavity of the control pin body. In other embodiments, the heater may be located within the spout body and transferring heat to the control pin.



Inventors:
Cooper, Timothy James (Rathdrum, ID, US)
Imthurn, James A. (Hauser, ID, US)
Application Number:
12/228143
Publication Date:
02/11/2010
Filing Date:
08/08/2008
Primary Class:
Other Classes:
222/593
International Classes:
B22D37/00; B22D35/06
View Patent Images:
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Foreign References:
JPH0952155A1997-02-25
Primary Examiner:
ABOAGYE, MICHAEL
Attorney, Agent or Firm:
Wells St. John P.S. (Spokane, WA, US)
Claims:
We claim:

1. A control pin for use in controlling the flow of molten metal in a molten metal distribution system for casting, the control pin comprising: a control pin body with an internal cavity and an outer surface, wherein the outer surface is sized and configured to operatively interact with an internal surface of a spout to effectively control molten metal flow through a spout aperture; and a heater element within the internal cavity of the control pin body.

2. A control pin as recited in claim 1, and further wherein a thermocouple is located within the internal cavity of the control pin body to provide temperature information from within the control pin body.

3. A control pin as recited in claim 1, and further wherein the heater element is molded into the control pin body.

4. A control pin as recited in claim 1, and further wherein the control pin body is made at least partially of a laminated composite ceramic material that includes multiple layers of a reinforcing fabric embodied within a cast ceramic matrix.

5. A heat control system for use in a combination of a control pin and a spout used in managing molten metal flow from a molten metal distribution system into a casting mold, the preheat control system comprised of: a control pin with a control pin body; a spout with a spout body; a heater in one of the control pin body or in the spout body; wherein heat is transferred from the heater through one of the control pin body or the spout body, to the other one of the control pin body or the spout body, to preheat both the control pin body and the spout body.

6. A method for heating a control pin used in controlling the flow of molten metal through a molten metal distribution system and into casting molds, the method comprising the following: providing a spout with a spout aperture configured to facilitate flow of molten metal from the molten metal distribution system into casting molds; providing a control pin body with an internal cavity and an outer surface, wherein the outer surface is sized and configured to control the opening between the spout aperture and control pin when the control pin is inserted therein; providing a heater within the internal cavity of the control pin body; increasing the temperature of the heater within the control pin to pre-heat the control pin prior to introducing metal to the spout; and positioning the control pin into the spout to control the flow of molten metal through the spout.

7. A method for heating a control pin as recited in claim 6, and further comprising retracting the control pin from the spout to thereby allow molten metal to flow through the spout.

8. A method for heating a control pin as recited in claim 6, and further increasing the temperature of the heater sufficient to additionally pre-heat the spout.

Description:

CROSS REFERENCE TO RELATED APPLICATION

This application does not claim priority from any other application.

TECHNICAL FIELD

This invention pertains to a control pin and spout system for pre-heating and/or heating the metal casting distribution spout configurations for pouring non-ferrous metal such as molten aluminum into casting molds; more particularly, a metal flow control pin and/or spout configuration which provides heat before, during and/or after casting at the metal flow control pin and/or spout.

BACKGROUND OF THE INVENTION

Metal ingots, billets and other castparts may be formed by a casting process which utilizes a vertically oriented mold situated above a large casting pit beneath the floor level of the metal casting facility, although this invention may also be utilized in horizontal molds. The lower component of the vertical casting mold is a starting block. When the casting process begins, the starting blocks are in their upward-most position and in the molds. As molten metal is poured into the mold bore or cavity and cooled (typically by water), the starting block is slowly lowered at a pre-determined rate by a hydraulic cylinder or other device. As the starting block is lowered, solidified metal or aluminum emerges from the bottom of the mold and ingots, rounds or billets of various geometries are formed, which may also be referred to herein as castparts.

While the invention applies to the casting of metals in general, including without limitation aluminum, brass, lead, zinc, magnesium, copper, steel, etc., the examples given and preferred embodiment disclosed may be directed to aluminum, and therefore the term aluminum or molten metal may be used throughout for consistency even though the invention applies more generally to metals.

While there are numerous ways to achieve and configure a vertical casting arrangement, FIG. 1 illustrates one example. In FIG. 1, the vertical casting of aluminum generally occurs beneath the elevation level of the factory floor in a casting pit. Directly beneath the casting pit floor 101a is a caisson 103, in which the barrel 102 for the hydraulic cylinder is placed.

As shown in FIG. 1, the components of the lower portion of a typical vertical aluminum casting apparatus, shown within a casting pit 101 and a caisson 103, are a hydraulic cylinder barrel 102, a ram 106, a mounting base housing 105, and a starting block base 114 (also referred to as a starting head or bottom block), all shown at elevations below the casting facility floor 104.

The mounting base housing 105 is mounted to the floor 101a of the casting pit 101, below which is the caisson 103. The caisson 103 is defined by its side walls 103b and its floor 103a.

A typical mold table assembly 110 is also shown in FIG. 1, which can be tilted as shown by hydraulic cylinder 111 pushing mold table tilt arm 110a such that it pivots about point 112 and thereby raises and rotates the main casting frame assembly, as shown in FIG. 1. There are also mold table carriages which allow the mold table assemblies to be moved to and from the casting position above the casting pit.

FIG. 1 further shows the starting block base 114 partially descended into the casting pit 101 with castpart or ingot 113 being partially formed. Ingot 113 is on the starting block base 114, which may include a starting head or bottom block, which usually (but not always) sits on the starting block base 114, all of which are known in the art and need not therefore be shown or described in greater detail. While the term starting block is used for item 114, it should be noted that the terms bottom block and starting head are also used in the industry to refer to item 114, bottom block typically used when an ingot is being cast and starting head when a billet is being cast.

When hydraulic fluid is introduced into the hydraulic cylinder at sufficient pressure, the ram 106, and consequently the starting block 114, are raised to the desired elevation start level for the casting process, which is when the starting blocks are within the mold table assembly 110.

The lowering of the starting block 114 may be accomplished by any one of a number of different means or mechanisms, such as hydraulic as shown, ball screws or cable systems. The embodiment shown in the figure may utilize a metering of the hydraulic fluid from the hydraulic cylinder at a pre-determined rate, thereby lowering the ram 106 and consequently the starting block at a pre-determined and controlled rate (which may also be subject to manual intervention by operators or controllers). The mold is controllably cooled during the process to assist in the solidification of the emerging ingots or billets, typically using water cooling means.

There are numerous mold and casting technologies that fit into mold tables, and no one in particular is required to practice the various embodiments of this invention, since they are known by those of ordinary skill in the art.

The upper side of the typical mold table operatively connects to, or interacts with, the metal distribution system. The typical mold table also operatively connects to the molds which it houses.

When metal is cast using a continuous cast vertical mold, the molten metal is cooled in the mold and continuously emerges from the lower end of the mold as the starting block base is lowered. The emerging billet, ingot or other configuration is intended to be sufficiently solidified such that it maintains its desired shape. Below that, there is also a mold air cavity between the emerging solidified metal and the lower portion of the mold and related equipment.

After a particular cast is completed, as described above, the mold table is typically tilted upward and away from the top of the casting pit, as shown in FIG. 1.

It is generally desired to avoid any solidification of the molten metal in the distribution system and substantial efforts are employed to avoid solidification as it may result in blockages and require that casts be aborted, which consequently results in undesirable down time of the production of the non-ferrous metal. In particular metal distribution systems, spouts are utilized to distribute and pour molten metal such as aluminum into molds, including molds which produce castparts referred to as ingots. Some of these distribution systems may be comprised of troughs which distribute molten metal to the necessary molds, all of which are generally known and used in the industry. A series of dams and other blocking devices may be used to initiate, stop or otherwise control the flow to some or all of the molds, in aspects of this invention.

It is the control pins that are generally used to control the flow of the molten metal as delivered to the spouts from the metal distribution system, although the control pins may also be utilized for some part of the starting and stopping of molten metal flow through the spouts and into the molds. Due to several factors such as the surface area to volume and temperature of metal, the spout areas present an area where the molten metal tends to solidify if the process is not sufficiently controlled. Solidification of a sufficient amount of molten metal at the spout area results in the uneven flow of molten metal into one mold versus another in a mold table with multiple molds and may lead to blockage of the spout and/or the need to abort a cast before it is completed.

Heated spout pins or control pins are generally placed within the aperture in the spout to block the aperture or plug the hole when desired, normally at the beginning and at the end of the cast. At the beginning of the cast for instance, the control pins are placed within the apertures in the spouts to block the flow of molten metal to the molds until the desired time, such as when all molds can be supplied approximately simultaneously. These control pins are then moved to change the aperture size to vary metal flow rates over the length of cast. At the end of a cast on a mold table with a plurality of molds, there would generally be a plurality of spouts and personnel would generally hurry to remove the control pins in each spout to avoid molten metal solidifying in the spout and creating undesirable issues for the next cast as the spout refractory material is typically at a temperature which would cause the solidification of the metal at that interface. In some molten metal level control systems, the spout is plugged until the launder is full and then the control pins are removed and the spouts opened, there by controlling the metal flow as shown in FIG. 8.

It is therefore an objective of some embodiments of this invention to provide a mechanism to avoid the solidification of the molten metal at or on the spout surface and/or at or on the surface of the control spout pins.

Some advantages that may be achieved by different embodiments or aspects of this invention, although not required, may be the reduction or elimination of freeze ups due to solidification of molten metal. Three steps result in a shutdown of the system, cleaning of the freeze up area and then re-starting or initiating the casting process (which takes unnecessary time and requires unnecessary expense). It may for example in some applications require a twenty-five minute cool down period before action may be taken at the control pin and spout location and then another forty-five minutes to reheat to prepare for the next casting. Embodiments of this invention may also eliminate heating ovens which may be used in prior art to maintain temperatures at a sufficient level.

Another possible advantage in the utilization of embodiments of this invention is that if a thermocouple is used, data provided by the thermocouple readings may give an indication of the health or status of the control pin and spout, allowing preventative maintenance to be performed, which should reduce unexpected failures in some cases.

Another possible advantage in some embodiments of this invention is the saving of time, namely time in dealing with spout heaters. A further advantage of embodiments of this invention may be that better control may be maintained over the process at temperatures inherent in the process. A still further advantage of embodiments of this invention is the reduction of personnel time in and around the molds to deal with some or all of the problems described above and which may be eliminated by this invention.

Although embodiments and aspects of this invention are directed to the objective(s) stated above, and/or to some of the advantages stated above, it will be appreciated by those of ordinary skill in the art that this invention is not limited to any one objective or any one or more advantages.

Other objects, features, and advantages of this invention will appear from the specification, claims, and accompanying drawings which form a part hereof. In carrying out the objects of this invention, it is to be understood that its essential features are susceptible to change in design and structural arrangement, with only one practicle, and preferred embodiment being illustrated in the accompanying drawings, as required.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below with reference to the following accompanying drawings.

FIG. 1 is an elevation view of a prior art vertical casting pit, caisson and metal casting apparatus;

FIG. 2 is a cross-sectional view of a prior art control pin configuration, illustrating a solid control pin in the spout of a distribution trough, in one example of a semi-continuous metal distribution and casting system;

FIG. 3 is a cross-sectional view of one embodiment of a control pin and spout system in a semi-continuous metal distribution and casting system contemplated by this invention;

FIG. 4 is the cross-sectional view of one embodiment of the control pin and spout system illustrated in FIG. 3, only wherein the control pin has been removed from blocking molten metal flow through the spout;

FIG. 5 is a perspective cross-sectional view of an embodiment of a control system spout pin which may be utilized as contemplated by this invention;

FIG. 6 is a cross-sectional view of an embodiment of a control system spout pin which may be utilized as contemplated by this invention;

FIG. 6A is portion 6A from FIG. 6 of the embodiment of the control system spout pin which may be utilized as contemplated by this invention;

FIG. 6B is portion 6B from FIG. 6 of the embodiment of the control system spout pin which may be utilized as contemplated by this invention;

FIG. 7 is a cross-sectional view of an embodiment of a control system spout which may be utilized as contemplated by this invention, wherein the spout includes a heating element to provide heat;

FIG. 7A is detail 7A from FIG. 7;

FIG. 8 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the top portion of the spout;

FIG. 9 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the middle portion of the spout;

FIG. 10 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the lower portion of the spout;

FIG. 11 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the middle portion of the spout;

FIG. 12 is an exemplary elevation cross-sectional view of one example of another embodiment of this invention illustrating heat transfer from the control pin to the spout; and

FIG. 13 is an exemplary elevation cross-sectional view of one example of another embodiment of this invention illustrating heat transfer from the spout to the control pin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Many of the fastening, connection, manufacturing and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art or science; therefore, they will not be discussed in significant detail. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application or embodiment of any element may already be widely known or used in the art or by persons skilled in the art or science; therefore, each will not be discussed in significant detail.

The terms “a,” “an,” and “the” as used in the claims herein are used in conformance with long-standing claim drafting practice and not in a limiting way. Unless specifically set forth herein, the terms “a”, “an”, and “the” are not limited to one of such elements, but instead mean “at least one.”

FIG. 1 is an elevation view of a typical prior art vertical casting pit, caisson and metal casting apparatus, and is described in more detail above.

FIG. 2 is a cross-sectional view of a prior art control pin configuration, illustrating a solid control pin in the spout of a distribution trough, in one example of a semi-continuous metal distribution and casting system. FIG. 2 illustrates molten metal distribution launder 125, molten metal distribution trough 120, refractory material 122 defining molten metal distribution trough 120, launder framework 123, spout 127 and control arm 132. The cast part mold framework 129 is shown above bottom block 130 before the beginning of a cast.

It will be appreciated by those of ordinary skill in the art the extent to which cooler surfaces, when interfacing with molten metal, may cause a cooling or solidification of the molten metal on the surface of the material, which would typically be a refractory material. For instance the metal distribution trough 120 shown in FIG. 2 is made of any one of a number of refractory materials designed to withstand the high heat present in molten metal casting systems. Prior art control pins 121 are generally made of a refractory material and solid core, although some tubular or hollow pins such as that disclosed in U.S. Pat. No. 7,165,757, issued Jan. 23, 2007, are constructed or comprised of different materials and combinations. The lower end 121a of control pin 121 is shown inserted in spout 127 to control the flow of metal there-through.

In a typical casting facility there would be trough configurations above a plurality of molten metal casting molds with a plurality of control pins 121 inserted in spouts such as spout 127 to control the flow of molten metal provided into the trough configuration. Once the molten metal is provided throughout the trough system, it is generally desirable to simultaneously provide the molten metal to the molds through the spout, and this is accomplished through known distribution system flow control methods, such as dams and other devices. The molten metal then flows through the control pin 121 and spout 127 configuration, with the control pin 121 being utilized to control the flow of the molten metal It can be seen from the configuration of the spout 127 and control pin 121 how blockages may occur in and around the spout 127, the aperture in the spout and the control pin 121.

It will be appreciated by those of ordinary skill in the industry that the term “control pin” or “pin” is used to identify the component referred to herein. For purposes of this invention that term will be used, however, it is not used to limit the component to any particular shape, geometry or configuration—but instead any such configuration utilized to control or manage the flow of molten metal through the spout may be contemplated in aspects of this invention. Some examples are shown in later figures, but they are by no means a limitation on the different shapes or configurations that may be utilized to practice different embodiments and aspects of this invention. In some cases the pin may be referred to as a plug, but many do not however completely plug the flow of molten metal, but instead control it.

FIG. 3 is a cross-sectional view of one embodiment of a control pin 143 contemplated by this invention, inserted into spout 144 and partially or wholly blocking the flow of molten metal 140 through the aperture. FIG. 3 illustrates molten metal distribution launder 138, launder framework 123, trough 139 defined by refractory material 122 and the inner surface 147 of the molten metal distribution trough 139, with molten metal 140 contained therein, and control arm 132.

FIG. 3 further illustrates one example of an embodiment of a control pin 143 contemplated by this invention inserted into spout 144 and blocking the flow of molten metal 140 through the aperture in spout 144. Lines 145 illustrate the flow of heat from control pin 143 into spout 144 and partially into the trough area, which tends to maintain an outer surface of control pin 143 and a suitable temperature such that molten metal does not solidify on that outer surface, or on the inner surface within the aperture in spout 144. More detail on control pin 143 is provided in later figures.

FIG. 3 further illustrates how heat provided from within the interior cavity of control pin 143 will not only heat the external or outer surface of control pin 143, but may also be configured or designed to also transfer heat to the spout 144 and internal surface of spout 144. This has the effect of reducing the tendency for molten metal to solidify on the outer surface of the control pin 143 and on the inner surface of spout 144.

The hollow control pin configuration illustrated in the embodiment of the invention shown in FIG. 3 may be constructed out of any one of a number of different refractory materials, with a material such as one at least partially comprised of a composite ceramic material which includes a fibrous reinforcing material embedded within a ceramic matrix such as disclosed in U.S. Pat. No. 7,165,757.

The vertical movement of control pin 143 may be accomplished by any one of a number of different mechanisms known or yet to be discovered in the art. One example of such is a control system which includes a linear actuator work in combination with a fulcrum.

The heating may be provided by any one of a number of mechanisms, means or sources within the contemplation of this invention, including without limitation, electric resistance heat as shown, inductive heating, hot air or gas flame heating, and also a chemical reaction of some sort, as will be appreciated by those of ordinary skill.

FIG. 4 is the cross-sectional view of one embodiment of the control pin and spout system illustrated in FIG. 3, only wherein the control pin has been removed from blocking molten metal flow through the spout. FIG. 4 illustrates control arm 132 rotated to lift control pin 143 as illustrated by arrow 150 such that control pin 143 is no longer blocking the molten metal in molten metal distribution trough 139 from flowing through the internal passageway through spout 144, as shown by metal flow arrows 152. The lower end 143a of control pin 143 is shown above the entry opening to spout 144. All other items shown in FIG. 4 are like items to those shown in FIG. 3 and will not therefore be described in further detail here.

FIGS. 3 and 4 further illustrate how control pin 143 may be housed, secured or held by control pin holder 137 in order to secure a hollow or tubular control pin such as control pin 143 for vertical movement and location, and to help facilitate the providing of heating elements such as heating coils, and heating control elements such as thermocouples, within the interior cavity of hollow control pin 143. Control pin holder 137 will have an internal cavity which generally corresponds to the external surface and configuration of control pin 143 to allow it to be secured thereto by any one of a number of different mechanisms, such as for example with a mechanical pin, or by placing glue there-between.

Those of ordinary skill in the art understand that in normal prior art operations, there is a rush to place the prior art control pins into place within the spout, and to start the cast, before cooling of the pin and spout occurs so that solidification does not result in casting delays. In some prior art systems, an external gas spout heater is utilized to heat the spout in an attempt to prevent or reduce solidification of molten metal in the spout area and embodiments of this invention will allow the elimination of spout heaters in the molten metal systems.

It may be desirable or preferred in some embodiments of this invention to discontinue providing heat through the control pin once casting or pouring has commenced because the molten metal will provide sufficient heat during that time frame; however, it may also be desirable in other applications to continue to provide power to the heating coils through the pouring process to further assure no undesired solidification of molten metal.

FIG. 5 is a perspective cross-sectional view of an embodiment of a control pin 170 and spout system which may be utilized as contemplated by this invention. FIG. 5 illustrates control pin 170 with control pin body 142, a hollow or tubular body 142 with an internal cavity therein and being closed at its lower end 142c. Tubular body 142 includes lower body portion 142a, and central body portion 142b, and upper body portion 142d. The upper body portion 142d has a reduced diameter (although not necessarily required to practice embodiments of this invention) where the pin holder 137 (shown in other figures) operatively attaches thereto. Control pin holder apertures 173 may be utilized to interact with or operatively attach control pin 170 to control pin holder 137 (shown in prior figure).

While the embodiment of the control pin body illustrated includes an internal cavity into which the heater is inserted or mounted, the term internal cavity as used herein and in the claims may also include embodiments wherein the heater coil or heater unit is molded into the control pin body such that its outer boundaries or surfaces comprise the internal cavity. The same use of internal cavity will be used if heater elements are within (such as molded within) the spout (as described below with respect to FIG. 7).

FIG. 5 further illustrates control pin inner cavity liner 151 within control pin inner cavity 145, heating coil 143, and heating coil electrical conductors 171. FIG. 5 also schematically shows thermocouple 147 within the interior cavity 145 of control pin 170, which may be utilized for control and process purposes to monitor and control the desired heat or temperatures. It will be appreciated by those of ordinary skill in the art that any one of a number of different types and configurations of thermocouples may be utilized to monitor and/or control the temperature which the heating coil 143 brings the control pin to. Thermocouples may also be utilized within or near the spout or inner surface of the spout, such as the thermocouple shown in FIG. 3 as item 152. This thermocouple may be utilized to monitor and control when the temperature of the style has reached a predetermined or desired level for process control purposes.

Although it will be appreciated by those of ordinary skill in the art that no particular heater element or coil is required to practice this invention, that a 500 Watt, 220 Volt configuration may be utilized to provide the desired amount of heat within control pin 170. It will be further appreciated by those of ordinary skill in the art that any one of a number of different types of specific thermocouples may also be utilized within control pin 170 in order to monitor and control the temperature and heat provided within control pin 170, all within the contemplation of embodiments of this invention.

FIG. 5 also schematically illustrates controller 155 which may be utilized to receive data and control the electrical input through heater coils 143 to reach the desired or predetermined temperature, which may be monitored and controlled through use of one or more thermocouples 147 operatively connected to controller 155. It will be appreciated by those of ordinary skill in the art that suitable thermocouple controllers and/or an electric heater controller, are well-known and used in the art and will not therefore be described further herein, and no one particular type or kind is required to practice embodiments of this invention.

While there is no specific portion or distance over which heat must be provided to practice in embodiments of this invention, it may be preferred in some embodiments to provide a heater coil and heat to the lower portion of the control pin, which may be for example the lower ten inches. In the embodiment shown, the middle portion of the control pin 170 may be approximately twelve inches and the top portion may be referred to as the cold zone or top portion. It may be desirable to maintain a certain minimum distance between the top of the control pin 170 and the molten metal because the tope of the control pin 170 may be where wires or other connections are exposed and a minimum distance may serve to protect or preserve those components.

In one exemplary embodiment or application, the system may preheat the control pin and/or spout for approximately one hour to a temperature within the control pin for example reaching nine hundred to one thousand degrees Celsius, whereas the temperature between the outer surface of the control pin and the spout may be approximately four hundred fifty degrees Celsius.

FIG. 6 is a cross-sectional view of an embodiment of a control pin 170 which may be utilized as contemplated by embodiments of this invention. FIG. 6 illustrates control pin 170 represented in two sections, namely section 6A and section 6B, which are presented in FIG. 6 for illustrative purposes and more detail. Control pin body 142 is shown with lower portion 142a and lower end 142c. Control pin holder apertures 173 are shown toward the upper end of control pin 170 and are utilized to operatively attach control pin 170 to a control pin holder (not shown in FIG. 6). FIG. 6 further illustrates an exemplary thermocouple 181 with thermocouple wires 182 operatively attached thereto and extending through the interior cavity 145 of control pin 170 a controller or monitor for monitoring the temperature and increasing or decreasing electrical input to the electrical coil to increase or decrease the heater temperature of the exterior surface of the control pin or of the interior surface of the spout (shown in other figures).

FIG. 6 further illustrates electrical heater coil 143 with heater coil conductor 171 operatively attached thereto and extending through the interior cavity 145 of control pin 170. FIG. 6 also illustrates internal cavity liner 151 within internal cavity 145 of control pin 170. The internal liner 151 may be made of any one of a number of different materials or compositions, with no one in particular being required to practice this invention. However, stainless steel may be utilized in embodiments such as those shown herein.

FIG. 6A is portion 6A from FIG. 6 of the embodiment of the control pin and spout system which may be utilized as contemplated by this invention. The same items referred to are numbered in a like manner and will not be further described herein.

FIG. 6B is portion 6B from FIG. 6 of the embodiment of the control pin and spout system which may be utilized as contemplated by this invention. The same items referred to are numbered in a like manner and will not be further described herein.

FIG. 7 is a cross-sectional view of an embodiment of a control system spout which may be utilized as contemplated by this invention, wherein the spout includes a heating element to provide heat. FIG. 7 illustrates another embodiment of this invention wherein the heater coils 208 are cast into spout 205, or embedded therein.

FIG. 7 illustrates distribution trough 200, refractory material 201, control pin holder 204, molten metal 202, spout 205, control pin body 207, control pin interior cavity liner 211, and molten metal distribution launder framework 209. FIG. 7 also illustrates how control pin holder 204 utilizes pins 199 inserted into control pin 207 apertures such as shown as items 173 in FIG. 5. Control pin holder adapter 203 secures and surrounds control pin holder 204.

FIG. 7A is detail 7A from FIG. 7, and illustrates control pin 207, spout 205, heater coils 208, and the arrows 210 illustrate that heater coils 208 are in a circular or coiled pattern around the control pin 205.

FIG. 8 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the top portion of the spout. FIG. 8 illustrates refractory material 201, molten metal 202, molten metal distribution launder framework 209, and spout 251 with spout aperture 252 through which molten metal flows. In FIG. 8 a control pin 250 with heater elements therein 248, shown attached to control pin shaft 249 (control pin shaft 249 may be considered part of or integral with control pin 250, or separate therefrom). The heater 248 in control pin 250 may also be sized sufficiently to allow sufficient transfer of heat from heater 248, through control pin body and to the upper portion of spout 251.

As will be appreciated by those of ordinary skill in the art, the control pins are used to control the flow of molten metal and due to operational issues, may not completely plug the aperture 252 in the spout 251. The control may be exerted at any location within or relative to the spout aperture 252 in spout 251, such as at or near the top of the spout as shown in FIG. 8, at or near the middle portion of the spout 251 (as shown for example in FIGS. 9 & 11), or at or near the lower portion of the spout 251 (as shown for example in FIG. 10), all within the contemplation of embodiments of this invention.

FIG. 9 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the middle portion of the spout 251. FIG. 9 illustrates refractory material 201, molten metal 202, molten metal distribution launder framework 209, and spout 251 with spout aperture 252 through which molten metal flows. FIG. 9 further illustrates control pin 261, control pin shaft 260 and heater 262, with the embodiment of the control pin 261 shown controlling the flow of molten metal through the spout aperture 252 in spout 251 in the middle portion of the spout 251.

FIG. 10 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the lower portion of the spout. FIG. 10 illustrates refractory material 201, molten metal 202, molten metal distribution launder framework 209, and spout 251 with spout aperture 252 through which molten metal flows. FIG. 10 further illustrates control pin 271, control pin shaft 270 and also includes a heater although not specifically identified in FIG. 10, with the embodiment of the control pin 271 shown controlling the flow of molten metal through the spout aperture 252 in spout 251 at or near the lower portion of the spout 251.

FIG. 11 is an exemplary elevation cross-sectional view of one example of another embodiment of components that may be utilized in practicing aspects of this invention, showing a differently configured control pin primarily controlling the flow of molten metal generally at or toward the middle portion of the spout. FIG. 11 illustrates refractory material 201, molten metal 202, molten metal distribution launder framework 209, and spout 251 with spout aperture 252 through which molten metal flows. FIG. 11 further illustrates control pin 281, control pin shaft 280 and also includes a heater although not specifically identified in FIG. 11, with the embodiment of the control pin 281 shown controlling the flow of molten metal through the aperture 252 in spout 251 at or near the lower portion of the spout 251.

FIG. 12 is an exemplary elevation cross-sectional view of one example of another embodiment of this invention illustrating heat transfer represented by arrows 291 from the heater in the control pin 290, through the control pin body portion, and to the spout 194 by either or both of conduction and convection, depending on the level and nature of contact between the outer surface of the control pin 290 and the interior surface of the aperture 293 in the spout 251. FIG. 12 also illustrates refractory material 201, molten metal 202, and molten metal distribution launder framework 209. It will be appreciated therefore that this invention facilitates the use of either the spout body and/or the control pin body as a heat transfer medium to transfer heat from the heater which is in the internal cavity of either the spout body or the control pin body, through that body and to the body of the other (either the spout body or the control pin body), to achieve the desired preheating of the system.

In its broadest sense, this invention would include embodiments wherein the body of the control pin 290 is not only pre-heated itself, but is also used as a heat transfer conduit or medium to transfer heat and thereby pre-heat the spout as well.

FIG. 13 is an exemplary elevation cross-sectional view of one example of another embodiment of this invention illustrating heat transfer represented by arrows 302 from the heater 301 in the spout 300 to the control pin 306. FIG. 13 also illustrates refractory material 201, molten metal 202, and molten metal distribution launder framework 209.

In its broadest sense, this invention would include embodiments wherein the body of the spout 300 is not only pre-heated itself with heater elements 301, but is also used as a heat transfer conduit or medium to transfer heat and thereby pre-heat the control pin 306 as well.

As will be appreciated by those of reasonable skill in the art, there are numerous embodiments to this invention, and variations of elements and components which may be used, all within the scope of this invention.

One embodiment of this invention, for example, a control pin for use in controlling the flow of molten metal in a molten metal distribution system for casting is disclosed, wherein the control pin comprises: a control pin body with an internal cavity and an outer surface, wherein the outer surface is sized and configured to operatively interact with an internal surface of a spout to effectively plug or control a spout aperture; and a heater element within the internal cavity of the control pin body. In further embodiments thereof, there may be a thermocouple located within the internal cavity of the control pin body to provide temperature information from within the control pin body. The control pin referred to herein may also, in some embodiments of this invention, further be configured wherein the heater element is molded into the control pin body; or wherein the control pin body is made at least partially of a laminated composite ceramic material that includes multiple layers of a reinforcing fabric embodied within a cast ceramic matrix.

In another embodiment of the invention, a preheat control system for use in a combination of a control pin and a spout used in managing molten metal flow from a molten metal distribution system into a casting mold is provided, wherein the preheat control system is comprised of: a control pin with a control pin body and an internal cavity within the control pin body; a spout with a spout body and an internal cavity within the spout body; a heater in one of the internal cavities within the control pin body or in the internal cavity in the spout body; wherein heat is transferred from the heater through one of the control pin body or the spout body, to the other one of the control pin body or the spout body, to preheat both the control pin body and the spout body.

In yet another embodiment of the invention, a method embodiment, a method is provided for preheating a control pin used in controlling the flow of molten metal through a molten metal distribution system and into casting molds wherein the method comprises the following: providing a spout with a spout aperture configured to facilitate flow of molten metal from the molten metal distribution system into casting molds; providing a control pin body with an internal cavity and an outer surface, wherein the outer surface is sized and configured to operatively plug the spout aperture when inserted therein; providing a heater within the internal cavity of the control pin body; inserting the control pin into the spout to prevent the flow of molten metal through the spout; increasing the temperature of the heater within the control pin to pre-heat the control pin prior to introducing metal to the spout; and retracting the control pin from the spout to thereby allow molten metal to flow through the spout. In further embodiments of the foregoing, the method may further comprise further increasing the temperature of the heater sufficient to additionally pre-heat the spout.

In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.