CN103492101A - Method and system for manufacturing railcar coupler locks - Google Patents

Abstract

A casting assembly for making a lock for a railcar coupler includes a drag portion and a cope portion of a first mold defining an exterior surface of the lock, wherein the first mold includes a first molding material. The casting assembly also includes a second mold made of a second molding material. The second mold defines a cavity having an inner surface substantially complementary to the outer surface of the first mold. A down runner is formed in the second mold. A gating system is formed in the second mold and is in fluid communication with the down runner. A gate is formed in the second mold and is in fluid communication with the gating system and the first mold.

Description

Method and system for manufacturing railcar coupler locks

Background technique

Rail car couplers are used to connect rail cars together. Typical couplers commonly used in North America are E or F couplers. These couplers incorporate a lock that interacts with the knuckle of the coupler to lock the knuckle into the closed position. Typically, the lock fits within a lock cavity in the knuckle body and overlies the knuckle tail. The width of the lock is sized to slide within the lock cavity.

The locks used in this type of coupler are usually made by casting. The most common technique used to manufacture locks is by sand casting. Sand casting is used to manufacture complex shapes with low cost and high output. In a typical sand casting process, a mold is formed by filling molding sand around a pattern, which generally defines a casting system through which molten metal flows. The pattern is then removed from the mold, forming a cavity in the shape of the cast piece, corresponding to the final casting. Cores, which define internal cavities and slots, are placed into the mold. The mold is then closed and filled with hot liquid metal through a down runner, where the metal cools. The solidified metal or rough casting is removed by separating the mold. The casting is then separated from the sprue, finished and cleaned by grinding, welding, heat treatment and machining.

In the sand casting process, the mold is built using sand as the base material, mixed with a binder to hold the shape. The mold is built in two parts, called a cope section (eg, upper half) and a drag section (eg, lower half), which are separated along a straight parting line. Swage slopes of up to 3 degrees or more are machined into the pattern to ensure that the pattern releases from the mold when removed. In some sand casting processes, an outer flask is used to support the sand during the through-cast molding process.

After the metal is poured into the mold, the casting cools and contracts as it approaches a solid state. As the metal shrinks, additional liquid metal must continue to be injected into the shrinking area, or holes will appear in the final part. In areas of high shrinkage, risers are formed into the mold to provide secondary storage during pouring. These risers are the last areas to solidify, thus allowing the contents to remain liquid longer than the cavity of the part being cast. As the contents of the cavity cool, the riser provides an area of contraction, ensuring the production of a solid final casting. The riser opening at the top of the cope mold also acts as a vent for gases to escape during pouring and cooling.

In various casting techniques, different sand binders are used to keep the sand in the shape of the model. These binders have a great influence on the final product as they control the dimensional stability, surface finish and realization of casting details in each specific process. The two most typical methods of sand casting include (1) green sand, which consists of silica sand, with clay and water as the binder; Chemical or resinous adhesive materials. Traditionally, locks are constructed using the green sand process because of its low cost in relation to the molding material.

While green sand has been effective in making locks for many years, the process has some drawbacks. For example, the surface of the lock is rough polished, and the thickness of the locking face of the lock varies. These roughness imperfections and variations must be addressed by grinding and other finishing operations to ensure that the final lock will meet dimensional requirements. Other problems with these casting processes will become apparent upon reading the following description.

Contents of the invention

It is an object of the present invention to provide a method of manufacturing a lock for a railcar coupler that substantially eliminates surface imperfections and dimensional variations. The method includes patterning the lock in a drag portion and a cope portion of a first mold comprising a first molding material to form a cavity defining an outer surface of the lock. A cavity is formed in the second mold with the second molding material. The cavity defines an inner surface substantially complementary to the outer surface of the first mold. A runner, a runner in fluid communication with the runner, a riser in fluid communication with the runner, and a sprue in fluid communication with the runner and the first mold are formed in the second mold. The first mold and the second mold are cured. The first mold is assembled and inserted into the cope portion of the second mold. The second mold is assembled and melt is poured into the sprue of the second mold. The melt then flows into the first mold to make the lock.

A second object of the present invention is to provide a method of manufacturing a lock for a railcar coupler comprising forming a pattern of the lock in a drag portion and a cope portion of a first mold comprising a first molding material to form a cavity that defines the outer surface of the lock. The cope portion defines a first opening configured to vent gas. A cavity having an interior surface substantially complementary to the exterior surface of the first mold is formed in a second mold containing a second molding material. A first opening provided to discharge gas exhausted from the first opening of the cope portion of the first mold is formed in the cope portion of the second mold. A sprue, a gating in fluid communication with the sprue, and a gate in fluid communication with the gating and the first mold are formed with a second molding material. The first mold and the second mold harden. The first mold is assembled and inserted into the cope portion of the second mold. The second mold is assembled, and the melt is injected into the sprue of the second mold. The melt then flows into the first mold to form a lock. Gas in the first mold is extruded by the melt through the first opening in the cope portion of the first mold and then through the first opening in the cope portion of the second mold.

A third object of the present invention is to provide a method of manufacturing a lock for a railcar coupler comprising forming at least two lock patterns in a drag portion and a coping portion of a mold comprising a naturally hardening molding material , thereby forming a cavity defining the outer surfaces of at least two locks. A sprue, a gating in fluid communication with the sprue, and at least two sprues each in fluid communication with the gating and one of the at least two cavities are formed of a naturally hardening molding material. Naturally hardening molding materials harden. The drag portion and cope portion of the mold are combined. The melt is injected into the sprue of the hardened natural hardening molding material, wherein the melt then flows through the gating system and into the cavity, thereby forming the at least two locks.

A fourth object of the present invention is to provide a casting assembly for the manufacture of locks for rail car couplers. The casting assembly includes a drag portion and a cope portion of a first mold defining an outer surface of the lock. The first mold contains a first molding material. The casting assembly also includes a second mold made of a second molding material. The second mold defines a cavity having an inner surface substantially complementary to the outer surface of the first mold. A down runner is formed in the second mold. A gating system is formed in the second mold and is in fluid communication with the down runner. A gate is formed in the second mold and is in fluid communication with the gating system and the first mold.

Other features and effects will become more apparent to those skilled in the art after studying the following figures and detailed description. All additional features and effects included in the specification should be within the protection scope of the claims and be protected by the following claims.

Description of drawings

The accompanying drawings are included to provide a further understanding of the claims, and are incorporated in and constitute a part of this specification. The described details and illustrated examples serve to explain the principles defined by the claims.

Figure 1 illustrates a perspective view of a lock within the body of a railcar coupler;

Figures 2a and 2b illustrate a perspective view and a side view, respectively, of the lock shown in Figure 1;

Figure 3 illustrates an outer mold combination that can be used to make the lock shown in Figures 2a and 2b;

Figures 4a and 4b illustrate the interior of the cope and drag portions of the outer mold shown in Figure 3, respectively;

Figure 5 illustrates an internal view of the outer mold after the melt has been poured;

Figure 6a illustrates a side view of the shell;

Figure 6b illustrates the cope and drag portions of the shell form shown in Figure 6a;

Figure 7a illustrates another view of the drag portion of the shell;

Figure 7b illustrates a cross-sectional view of the drag portion along the AA' section in Figure 7b;

Figure 8 illustrates part of the cavity of the lower mold box related to the cast lock;

Figure 9 illustrates the process used to manufacture the lock of Figure 2a.

Detailed ways

The following examples describe methods for making multiple locks in a single casting operation. Usually made into a set of shell shapes that define the shape of the lock. The shell type is a casting mold made of relatively expensive refined silica sand mixed with thermosetting phenolic resin. Refined silica sand allows the lock to have a smooth surface finish and relatively high dimensional accuracy compared to locks manufactured by other casting processes.

However, current shell production technology optimizes existing size shell machines and results in relatively small shells. Whereas the larger shell machines that exist tend to be very expensive. When technically feasible, it would be very expensive to increase the size of the shell to withstand the large discharge pressures required. Thus, the shell mold is put into the outer mold. The outer mold is made of less costly natural hardening or no-bake sand molding material and is configured to receive the shell. In the described embodiment, the outer mold is configured to accommodate four shell forms.

A gating system constituted in the outer mold is arranged to distribute the melt poured into the mold to each shell mold through a sprue. Vents in the shell allow air and other gases to escape as the melt fills the shell. This vent usually lines up with a vent in the outer mold to allow gases to vent to the atmosphere.

FIG. 1 illustrates a perspective view of a lock 105 within a body 100 of a rail car coupler. Figures 2a and 2b illustrate a perspective view and a side view, respectively, of the lock 105 shown in Figure 1 . The lock 105 includes a rear leading end 205 , a central post portion 210 , and a knuckle side end 215 . The knuckle side end 215 defines a groove 220 . Adjacent the rear leading end 205 , the lock 105 defines a knuckle lock face 225 and a coupler lock face 230 .

Operating the lock 105 requires sliding the lock 105 within the lock cavity of the knuckle body and over the knuckle tail. In order for the lock 105 to function smoothly, the knuckle lock face 225 and coupler lock face 230 must be substantially parallel to each other and smooth. In addition, the distance D207 between these two faces of the different locks must be precise and consistent. The lock 105 made by the disclosed casting process has a distance D207 of about 3.060 inches, and the variation between locks is less than about ±0.010 inches. These dimensions can be achieved by the claimed casting process plus minimal machining of the lock. Locks produced by known manufacturing processes must be machined to produce a smooth surface, either by sandblasting or otherwise. Castings with relatively fine vent holes can be forged, leaving relatively small areas for grinding. Likewise, a cast connection 505 ( FIG. 5 ) connects the lock 105 to a detachable casting gating from the end face 207 of the rear leading end 205 . In some cases, the residual casting of connector 505 may not require further grinding since end face 207 is generally not a critical face.

FIG. 3 illustrates a closed overmold assembly 300 that may be used to make the lock 105 described above. The outer mold 300 includes a cope portion 305 and a drag portion 307 . Cope and drag sections 305 and 307 are made of a molding material such as no-bake or no-dry sand. A sprue 320 is placed in the opening of the cope, through which molten metal is injected. The cope portion 305 defines first and second sets of vent openings 325 and 330 for exhausting gases generated within the cavity formed in and constituted by the outer mold 300 during the casting process. . A vent opening 335 may also be provided in one side of the drag portion 307 .

The molding material used in the outer mold 300 is a relatively low cost and stronger molding material that typically cannot be made into a lock with the required surface finish and dimensional accuracy details. For example, the molding material may have a grit size index (GFN) in the range of 44-55 grit size number.

In some embodiments, the molding material is reclaimed sand (ie, sand that has previously been used to make castings). Reclaimed sand can be obtained by subjecting used casting molds to various vibration and/or crushing processes which break down the casting molds and sort the sand into finer and finer component sizes until the desired grain size is obtained. The screening process helps to separate the sand by size. Finally, the sand is subjected to high temperatures to remove any residual overburden or other impurities, such as binder material. Next, reclaimed sand is mixed with new binder in a ratio of approximately 99:1 and placed in a mold to harden. Once hardened, the new mold is ready to contain the melt.

In some embodiments, two or more stages of molding material are used to make the outer mold 300 . For example, the outer layer 310 of the mold (ie, defining the exterior of the outer mold) may be made of low fine sand. The low-refined material was not subjected to the various separation procedures described above. For example, thermal processing may not be performed in order to save time. Additionally, lesser amounts of adhesive material can be used to bond low precision materials. For example, the ratio of sand to binder may be greater than 99:1.

The inner layer 315 of the mold may be made of high fine sand regenerated by the separation process described above. Utilizing different grades of recycled material reduces the overall manufacturing costs associated with the outer mold 300 due to the low fine sand required. High fine sand is reserved for only those parts of the outer mold 300 that require greater dimensional accuracy or a higher surface finish.

Figures 4a and 4b illustrate the interior of the cope portion 305 and the drag portion 307 of the outer mold 300, respectively. In FIG. 4 b , the shell form 400 placed in the drag box part 307 is also shown. The outer mold 300 is configured to accommodate four shells 400 . The inner surface of the outer mold 300 that is in contact with the shell 400 is configured to provide a compartment for the shell 400 so as to prevent the walls of the shell 400 from bursting under discharge pressure generated during injection of the melt into the mold 300 .

Each shell pattern 400 is configured to make an individual lock 105 . Thus, four locks 105 can be made in a single casting process. It will be appreciated that the outer mold 300 may be sized differently to accommodate different numbers of shells 400, thereby facilitating the casting of different numbers of locks 105 in a given casting process.

In the illustrated embodiment, four sets of vent openings 325 and 330 are provided in the cope portion 305 of the mold to vent gases from the four shells 400 . Vent openings 325 and 330 are generally positioned over respective vent openings 405 and 410 of shell form 400 .

The first set of vent openings 330 is positioned on the first set of vent openings 410 of the shell 400 adjacent to the shell 400 at a location corresponding to the first end of the lock (eg, the rear guide end 205 ). The second vent opening 325 is positioned over the second vent opening 405 of the shell profile 400 at a location on the shell profile 400 corresponding to the second end of the lock (eg, the knuckle side end 215 ). Side vents positioned adjacent to corresponding side vents 335 ( FIG. 3 ) formed in the shell mold 400 are formed in the drag portion 307 of the outer mold 307 .

Vent openings 330 and 325 in the outer mold cope portion 305 extend from the outer surface of the cope portion 305 (see FIG. 3 ) to the inner surface of the cope portion 305 (see FIG. 4 a ). The alignment of the various vent openings 330, 325, 405, and 410 is critical to enable complete removal of gases generated during the casting process. The vent openings 325 and 330 of the overmold upper mold portion 305 may be placed in the recess 422 to relax the positioning constraints of the vent openings 330 , 325 , 405 and 410 . Recess 422 is sized to ensure that gases exit through vent openings 405 and 410 of shell form 400 and other gases remain within recess 422 . That is, the recess 422 is sized to accommodate variations in the relative positioning between the vent openings 325 and 330 of the overmold box portion 305 and the vent openings 405 and 410 of the shell mold 405 . For example, the recess 422 is approximately 1 inch wide and approximately 2 inches long. The depth of the recess 422 is about 0.125 inches. It can be understood that recesses can also be formed on the shell 400 to achieve the same effect.

The positioning of vent holes 405 and 410 at both ends of lock 105 helps ensure that all gas within shell 400 has a way to escape. This results in a stronger lock 105 with fewer surface imperfections since the gas does not penetrate into the casting, and the gas can additionally constitute bubbles that make the lock 105 less secure. The location of the vent holes 405 and 410 also helps to ensure that the thicker upper section of the lock 105 (i.e. the rear leading end 205) and the thinner lower section of the lock 105 (i.e. the knuckle side end 215) remain stable and will not deform or Changing the dimensions makes for a noticeable difference in volume between these two lock segments.

As shown in FIG. 4 a , a pair of risers 415 are molded in the cope portion 305 of the outer mold 300 , and a gating system 420 is molded in the drag portion 307 of the outer mold 300 . During casting, the melt flows through the runner 320 into the outer mold 300 , through the gating system 420 , into the riser 415 , and finally through the gate 505 ( FIG. 5 ) connecting the shell mold 400 and the gating system 420 Shell type 400. As noted previously, risers 415 are cavities that are filled with melt during the infusion process. As the melt in other parts of the casting cools, the melt will flow from riser 415 into the casting. This in turn helps to avoid cracks in areas of the casting that cool more slowly than other areas in it.

Figure 5 illustrates an internal view of the outer mold 300 after the melt has been poured and solidified to form a casting. In a typical embodiment, the casting includes four locks 105 , gate 505 , gating system 420 , riser 415 and down runner 320 . The gates 505 to individual locks are sized to facilitate separation of the locks 105 from the casting by knocking or other forms of impact. In this regard, the diameter of the gate 505 may be between approximately 0.5 inches and 2 inches. In order to minimize post-separation machining, the gate 505 is advantageously located at the end face 207 of the rear leading end 205 ( FIG. 2 a ), where it is a less important part of the lock 105 . After the lock 105 is disengaged, the remainder of the casting (ie, the gating system, riser and down runner) can be melted down and used in a later casting process.

Figure 6a illustrates a side view of a shell form 400 corresponding to the shell form 400 described above. FIG. 6b illustrates the cope portion 605 and the drag portion 610 of the shell form 400 . The cope part 605 and the drag part 610 may be joined by an adhesive to form the shell 400 . For example, adhesives may be used to adhere the parts together.

The shell mold 400 is constructed by the so-called shell (hence the name shell mold) or hot box method, where resin sand or a sand/resin mixture is blown by air pressure into a hot metal pattern, forming a hardened shell over time. The sand may correspond to refined silica sand mixed with a thermosetting phenolic resin. For example, silicon may have a grit index in the range of 60-70 grit index. The form, which may be constructed of cast iron, is then heated to between 230°C and 315°C until the sand in the form hardens to the desired depth. That is, until the shell has the desired wall thickness. The shell is then removed from the model, and most of the unhardened sand mixture inside the shell is removed. The removed sand can be used in a subsequent shell casting process after the regeneration process.

The cope part 605 and the drag part 610 of the shell form 400 are made by different molds. Shell casting technology provides high dimensional stability. Each mold defines a portion of the connection opening 607 in each section through which the melt flows into the shell mold 400 . The mold defining cope portion 605 may correspond to a generally rectangular box with open sides into which sand is injected. The side walls of the box may be tapered to facilitate removal of the hardened cope portion 605 from the box. The push box portion of the lock 105 may be molded into the bottom side of the box. Additionally, a mold may be configured to form protrusions 620 in cope portion 605 . This protrusion 620 forms a recess 220 in the lock (Fig. 2a). In other words, grooves 220 are formed without the use of cores that are typically removed during casting. Therefore, the dimensional accuracy of the groove 220 is improved compared to a groove formed by core pulling. This thereby eliminates the machining steps required to form the grooves produced by known casting procedures, reducing costs.

The mold defining the drag portion 610 may correspond to a general closed box with a relatively small opening formed on one side. In a typical embodiment, an opening is formed on the side of the case that bounds the knuckle-side end 215 of the lock 105 . Sand is blown into the box through the opening and hardened as described above. The unhardened sand is removed through the small opening, leaving the vented cavity 710 (Fig. 7b).

Figure 7a illustrates the drag portion 610 after it has been removed from the model. As a result of the shell casting process, a residual buildup 705 of sand may form on the sides of the drag portion 605 , closest to the knuckle side end 215 . Excess unhardened sand is emptied from drag portion 610 through opening 335 formed inside buildup 705 . As shown in FIG. 3 , the opening 335 in the inside of the drag portion corresponds to the opening 335 in the side of the outer mold 300 . Removing excess sand will expose a vent cavity 710 in the drag section 605, as illustrated by the AA' section 712 of the drag section 605 shown in Figure 7b.

As shown in FIG. 8 , the mold for the drag portion 605 of the shell form 400 is configured so that the vent cavity 710 (dashed line) generally follows the shape of the post portion 210 of the lock 105 . That is, the vent cavity 710 is along a substantial portion of the lock 105 . This allows gases formed during casting to escape into the vent cavity 710 and out through the vent opening 335 without entering the casting, which, as previously pointed out, would otherwise cause the casting to have additional air pockets that would weaken the casting, or cause Surface blemishes need repairing. This form of vent hole further improves the dimensional accuracy of the lock 105 .

Returning to Figure 6a, as the parting line 615 separating the drag portion 610 from the cope portion 605 travels from the rear leading end 205 segment down through the strut portion 210 and to the knuckle side end 215, it constitutes a The non-linear path follows the natural shape of the contour of the lock 105 . This non-linear path facilitates self-alignment of the cope and drag portions 605 and 610 of the shell form 400 and results in a parting line 615 of the lock 105 that substantially follows the non-linear contour of the lock 105 .

Fig. 9 is a block diagram of the processes carried out in manufacturing the lock 105 as described above. At block 900, the cope and drag portions 605 and 610 of the shell mold 400 for casting the lock 105 are formed. The individual parts can be made of refined silica sand covered with a thermosetting phenolic resin coating. Sand is loaded into individual boxes delimiting the upper and lower molds and heated until a shell of the desired thickness is obtained. Excess sand is removed from the drag portion 610 of the shell mold 400 to expose the vent cavity 710 which facilitates the venting of gases from the drag portion 610 during casting. Cope and drag sections 605 and 610 are interconnected by adhesive. The non-linear parting line 615 separating the cope and drag sections 605 and 610 facilitates easy alignment of the various sections.

In block 905, the cope and drag portions 305 and 307 of the outer mold 300 are formed. The cope and drag sections 305 and 307 are made of relatively inexpensive material such as natural hardening or no-bake sand material. Reclaimed sand from a previous casting process may be used for parts of the outer mold 300 . The interior of the outer mold 300 is shaped to accommodate the shell 400 and provide a compartment for the shell 400 to support the walls of the shell 400 during casting.

The gating system 420 and one or more risers 415 may be molded inside the outer mold 300 . The gating system 420 is connected to each shell 400 through gates 505 . The gate 505 is sized to facilitate separation of the lock 105 from the casting by knocking or other form of impact.

At block 910 , the shell form 400 is inserted into the outer mold 300 . In block 912, the outer mold is assembled. Next at block 915 , the melt is injected into the sprue 320 of the outer mold 300 . The melt may be steel or other suitable material. The melt flows down through sprue 320 , through gating system 420 , and into shell mold 400 through connection 505 . Air or other gases that would otherwise be trapped in the shell mold 400 escape through the vent openings 405 and 410 defined in the cope portion 605 of the shell mold 400 and then through the cope portion 305 of the outer mold 300 The vent openings 325 and 330 defined in the escape. Vent openings 325 and 330 in outer mold 300 are generally positioned above vent openings 405 and 410 of shell mold 400 . Other gases escape from the shell mold 400 through a cavity formed in the drag portion 605 of the shell mold 400 . These gases exit through the openings 335 on the sides of the drag portion 605 of the shell mold 400 and are finally exhausted to the atmosphere through the openings on the sides of the outer mold 300 .

The hardened casting is removed from the casting mold 300 at block 920 . For example, the casting mold 300 can be split open to reveal the casting. The spent molding sand can be broken down and regenerated to form future casting molds.

At block 925, the lock 105 and casting are separated. For example, a hammer may be used to separate the gating 420 and connector 505 from the lock 105 .

In block 930, the lock 105 is machined. For example, the end face 207 of the lock 105 where the connector 505 is formed may be ground to a relatively smooth finish. All remaining material of the gating system can be ground flat. The remainder of the lock 105 may then be sandblasted to a glossy finish. After blasting, the lock 105 is ready for operational use. That is to say that the lock 105 is ready to be inserted into the coupler body 100 without further machining.

As previously stated, the exemplary embodiment used to make the lock facilitates the manufacture of the lock 105 requiring minimal machining. For example, a shell mold 400 made of fine silica sand is used to define the lock casting. The shell form 400 is supported by a relatively inexpensive outer mold made of a natural hardening or no-bake sand material. Various locks can be produced in the external mold by suitable various shell types. Gating systems and risers are formed in the outer mold to distribute the melt into the individual shell molds. Vent holes formed in the individual molds allow gases to escape, improving the lock's dimensional accuracy.

While various implementations of the examples have been described, it will be apparent to those skilled in the art that many more examples and implementations are possible within the scope of the claims. The various dimensions described above are exemplary only and can be changed as needed. Accordingly, it is obvious to a person skilled in the art that further embodiments and implementations are possible within the scope of protection of the claims. Therefore, the embodiments described above are only provided to help understanding of the claims, and do not limit the protection scope of the claims.

Claims (36)

1. A method of making a lock for a railcar coupler, wherein the lock has a rear guide at a first end, a strut portion at a midsection, and a groove at a second end, wherein the A knuckle side of the lock defining a knuckle face and a coupler side of the lock opposite the knuckle side defining a coupler face, the method comprising the steps of: forming a pattern of the lock in a drag portion and a cope portion of a first mold comprising a first molding material, thereby forming a cavity defining an outer surface of the lock; forming a cavity having an inner surface substantially complementary to an outer surface of said first mold in a second mold comprising a second molding material; Formed in the second mold is a runner, a runner in fluid communication with the runner, a riser in fluid communication with the runner, and a runner in fluid communication with the runner and the first mold. mouth; curing the first mold and the second mold; combining the drag portion and cope portion of the first mold; inserting the first mold into the second mold; combining the drag portion and cope portion of the second mold; and A melt is injected into the sprue of the second mold, wherein the melt then flows into the first mold to form the lock. 2. The method of claim 1, further comprising inserting the first mold into a cavity of the second mold. 3. The method according to claim 1, wherein the first casting mold is a shell type having a gate, and wherein during forming the first casting mold, the uncured first molding material is released from the mold through the vent opening. The first mold is removed, and the vent opening is defined on a side of at least one of a drag portion and a cope portion of the first mold such that a vent is exposed in the at least one portion. A cavity, wherein the vent cavity is not connected to the cavity defining the outer surface of the lock. 4. The method of claim 1, wherein the outer wall of the first mold is tapered. 5. The method of claim 1, wherein a parting line of the first mold separating the cope portion from the drag portion follows a non-linear profile of the lock. 6. The method of claim 1, wherein the first modeling material is a mixture of silica sand and thermosetting phenolic resin. 7. The method of claim 6, wherein the second modeling material is a natural hardening material. 8. The method of claim 7, wherein the second molding material comprises a first layer of mechanically separated sand forming the exterior of the mold, and a second layer forming the sand that will be in contact with the first mold. The interior of the second mold is mechanically and thermally separated from the sand. 9. The method of claim 1, wherein the first build material and the second build material are the same material. 10. The method of claim 1, wherein immediately after removing the lock from the first mold, the tolerance of the distance between the resulting knuckle face and the resulting coupler face of the resulting lock Approximately less than or equal to ±0.010 inches. 11. The method of claim 1, wherein at least one of the cope and drag portions of the first mold defines a protrusion forming the groove. 12. The method of claim 1 , wherein the interior of the drag portion of the second mold is configured to receive at least two shells and distribute the melt into the at least two shells of each. 13. The method of claim 1, wherein gates to the lock formed during casting are arranged to be separated. 14. The method of claim 13, wherein the gate is less than 2 inches in diameter. 15. The method of claim 13, wherein a gate to the lock is located on top of the first end of the lock. 16. A method of making a lock for a railcar coupler, wherein the lock has a rear guide at a first end, a post portion at a midsection, and a groove at a second end, wherein the A knuckle side of the lock defining a knuckle face and a coupler side of the lock opposite the knuckle side defining a coupler face, the method comprising the steps of: The lock is patterned in a drag portion and a cope portion of a first mold comprising a first molding material, thereby forming a cavity defining an outer surface of the lock, wherein the cope portion defines a cavity for a first opening for exhaust gas; forming a cavity having an inner surface substantially complementary to an outer surface of said first mold in a second mold comprising a second molding material; forming in the cope portion of the second mold a first opening configured to discharge gas exhausted from the first opening of the cope portion of the first mold; forming a sprue in the second mold, a gating in fluid communication with the sprue, and a gate in fluid communication with the gating and the first mold; curing the first mold and the second mold; combining the drag portion and cope portion of the first mold; inserting the first mold into the second mold; combining the drag portion and cope portion of the second mold; and injecting melt into a down runner of the second mold, wherein the melt then flows through the gating system and the sprue into the first mold to form the lock, wherein the first mold Gas is extruded by the melt through the first opening in the cope portion of the first mold and subsequently through the first opening in the cope portion of the second mold. 17. The method of claim 16, wherein the cope portion of the first mold defines a second opening for venting gas, wherein the first opening in the cope portion of the first mold is Located proximate to a first end of the lock, and a second opening in the cope portion of the first mold is disposed proximate to a second end of the lock. 18. The method of claim 17, wherein the first opening is provided at a location of the lock proximate to the top surface of the cope portion of the drag mold. 19. The method of claim 16, wherein the cope portion of the second mold defines a vent configured to vent gas expelled from the second opening of the cope portion of the first mold. Second opening. 20. The method of claim 16, wherein the cope portion of the second mold defines a recess surrounding the first opening in the cope portion of the second mold, and the recess The width of the recess is about 1 inch, and the length of the recess is about 2 inches. 21. The method of claim 20, wherein the recess is greater than about 0.125 inches deep. 22. The method of claim 16, wherein a cope portion of the first mold defines a vent cavity positioned in relation to an upper portion of a post forming the lock. areas of the mold portion substantially contiguous wherein the vent cavity does not receive melt during casting and is arranged to vent through an opening formed on a side of the cope portion of the first mold The gas is discharged through side openings formed in the second mold. 23. The method of claim 16, wherein immediately after removing the lock from the first mold, the tolerance of the distance between the upper and lower locking faces of the lock is less than or equal to about ± 0.020 inches. 24. A method of making a lock for a railcar coupler, wherein the lock has a rear guide at a first end, a strut portion at a midsection, and a knuckle side defining a groove at a second end, wherein adjacent the first A knuckle side of the lock at one end defines a knuckle face and a coupler side of the lock opposite the knuckle side defines a coupler face, the method comprising the steps of: forming patterns for at least two locks in a drag portion and a cope portion of a casting mold comprising naturally hardening molding material, thereby forming cavities defining outer surfaces of said at least two locks; A natural hardening molding material is used to form a runner, a gating system in fluid communication with the runner, and at least two gates, each of the gates being connected to the runner system and one of the at least two cavities a fluid communication; Harden natural hardening molding materials; combining the drag portion and cope portion of the mold; and The melt is injected into the sprue of the hardened natural hardening molding material, wherein the melt then flows through the gating system and into the cavity, thereby forming the at least two locks. 25. A cast assembly for making a lock for a railcar coupler, wherein the lock has a rear guide at a first end, a strut portion at a midsection, and a groove at a second end, wherein adjacent the first end A knuckle side of the lock defining a knuckle face and a coupler side of the lock opposite the knuckle side defining a coupler face, the cast assembly comprising: a drag portion and a cope portion of a first mold defining an outer surface of the lock, wherein the first mold comprises a first molding material; a second mold made of a second molding material, the second mold defining a cavity having an inner surface substantially complementary to the outer surface of the first mold; a down runner formed in the second mold; a gating formed in the second mold in fluid communication with the down runner; A gate formed in the second mold is in fluid communication with the gating system and the first mold. 26. The casting assembly of claim 25, wherein the first casting mold is a shell mold. 27. The casting assembly of claim 25, wherein a parting line of the first mold separating the cope portion from the drag portion follows the non-linear contour of the lock. 28. The foundry assembly of claim 25, wherein the first molding material is a mixture of covered silica sand and a thermosetting phenolic resin. 29. The casting assembly of claim 27, wherein the second molding material is a natural hardening material. 30. The casting assembly of claim 25, wherein the first molding material and the second molding material are the same material. 31. The casting assembly of claim 25, wherein at least one of the cope and drag portions of the first mold defines a protrusion forming the groove. 32. The casting assembly of claim 25, wherein the interior of the drag portion of the second mold is configured to receive at least two shell molds and to distribute melt to the at least two shells each of the types. 33. The casting assembly of claim 25, wherein gates to the lock formed during casting are arranged to be separated. 34. The foundry assembly of claim 33, wherein the gate has a diameter of less than about 2 inches. 35. The method of claim 33, wherein a gate to the lock is located on top of the first end. 36. A method of making a lock for a railcar coupler, wherein the lock has a rear guide at a first end, a post portion at a midsection, and a groove at a second end, wherein the A knuckle side of the lock defining a knuckle face and a coupler side of the lock opposite the knuckle side defining a coupler face, the method comprising the steps of: forming a pattern of the lock in a drag portion and a cope portion of a first mold comprising a first molding material, thereby forming a cavity defining an outer surface of the lock; forming a cavity in a second mold comprising a second molding material with an inner surface substantially complementary to an outer surface of said first mold; and Formed in the second mold is a runner, a runner in fluid communication with the runner, a riser in fluid communication with the runner, and a runner in fluid communication with the runner and the first mold mouth.

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