Patent Publication Number: US-6662853-B2

Title: Method of making bolsters and sideframes for railway car trucks

Description:
This is a division of application Ser. No. 09/748,584, filed on Dec. 22, 2000, which is a division of application, Ser. No. 09/524,469, filed on Mar. 13, 2000, now U.S. Pat. No. 6,330,862, which is a division of application Ser. No. 09/357,061, filed on Jul. 19, 1999, now U.S. Pat. No. 6,089,166, which is a division of application Ser. No. 09/058,680, filed on Apr. 10, 1998, now U.S. Pat. No. 5,967,053, which is a division of application Ser. No. 08/780,546 filed on Jan. 8, 1997, now U.S. Pat. No. 5,752,564, the entire disclosures being part of the disclosure of this application and being hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to three-piece railway car trucks, and more particularly, to a method of making bolsters and sideframes for use in such three-piece railway car trucks. 
     2. Description of the Prior Art 
     In the past, in making hollow cast metal bodies, it has been known to use cores made of bonded sand supported in green sand molds to produce the hollow castings. The cores have been used to create the hollows or open spaces in the castings. 
     Cores have commonly been made in core boxes, typically having cope and drag halves that are brought together along a parting line. There is a cavity in the core box, and a mixture of sand and bonding material are introduced into the cavity and cured. The core box cope and drag portions are then parted along the parting line, generally being pulled apart vertically. Because of the need to pull the cope and drag portions apart, the sizes and shapes of the cores to be produced have been limited: the cores have not been able to have parts that would interfere with the movement of the cope portions away from the drag and with removal of the cores from the cope and drag portions. Thus, it typically has been necessary to produce several different cores that are later joined or placed together in the green sand mold. 
     In the case of cast metal sideframes for railway trucks, many different core shapes have been needed to produce the basic shape of the interior of the sideframes. As shown in FIGS. 15-17, more than twenty cores have been required, with some different cores sometimes adhered together in a separate process step before being placed in a receiving cavity in the mold, and with many different cores and groups of cores separately placed in the mold. While some cores such as a window core and bolster opening cores have been supported on core prints, many of the cores have been supported on chaplets on the mold surface. In addition to the placement of the cores being a labor intensive operation, the use of such multiple cores has been problematic from a quality control standpoint. With so many joints between the faces of the multiple cores, there is a potential for many fins to be formed on the interior of the casting. To remove these fins through a finishing operation has been difficult since the fins are on the interior of the casting. Moreover, these fins create another potential quality control problem since they could give rise to stress risers that could form along the fins. Other potential quality control problems arise from the potential for shifting of the cores&#39; positions in the mold prior to or during the casting operation. If the cores shift position, the thickness of the walls of the casting could vary from the design. 
     In addition, multiple cores may be so thin that core rods are required to be used to support the sand. These core rods add to the cost of the process and complicate cleaning of the castings. 
     Another problem can arise in connection with areas of the sideframe around lightener holes and other openings in the sideframe wall. Metal fins can form around these openings, and sometimes form facing the interior of the casting. To finish such a casting by removing these fins may be difficult to accomplish manually since the fins are less accessible to the worker. In addition, it is very difficult to remove interior fins through automation. 
     Similar problems have arisen in producing cast metal bolsters for use in railway trucks. Like the sideframes, bolsters have hollow interiors, and have traditionally been made with multiple cores to form the interior walls and interior surfaces of the outer walls. Sixteen separate cores have been used to produce such castings, with cope and drag portions sometimes adhered to each other or juxtaposed along joints, as in the case of the sideframes cores, with chaplets supporting the cores on the mold surface, and with separate cores inserted into the cores to define holes for bolting side bearings and dead lever lugs to the bolster. 
     Similar problems as those outlined for sideframes have arisen with respect to quality control for bolsters. The positions of the cores on the chaplets may shift in the mold, creating the potential for making a casting with less than or more than desirable wall thicknesses. Bolster production has required that the multiple cores be placed in a mold in a labor intensive operation with multiple joints where stress risers could form. And like the sideframes, interior fins could form around lightener and other openings, fins that could be difficult and labor intensive to remove and that are not conducive to removal through automated finishing operations. Moreover, fins can form on the edges of the openings which can be stressed and damaged during the removal operation in the case of both sideframes and bolsters. 
     SUMMARY OF THE INVENTION 
     The present invention addresses various aspects of the prior art problems related to the production of cast metal bolsters and sideframes for three-piece railway car trucks. 
     The present invention provides a method of making a cast metal sideframe for a railway car truck. The sideframe has front and rear ends and pedestals at each end for mounting on wheelsets. The sideframe also has a top member that extends along a longitudinal axis between the front and rear ends. The sideframe has a tension member that has a bottom center portion and a pair of diagonal portions extending from the bottom center portion toward the pedestals. The sideframe has a bolster opening in the middle of the sideframe between the top member and the bottom center portion of the tension member. The sideframe has a vertical column on each side of the bolster opening. The top member has a top surface with a plurality of lightener openings. The sideframe has interior and exterior surfaces. The method comprises the steps of providing a mold having cope and drag mold surfaces, providing a core having a core outer surface for forming at least a part of the interior surface of the cast metal sideframe, placing the core in the mold, and pouring molten metal into the mold to form the cast metal sideframe. In the improved method of the present invention, the core includes at least one core print received in a mating cavity in the mold and a side window portion. The core print is connected to the core outer surface and corresponds in size, shape and position with one lightener opening to be produced in the top wall of the top member of the sideframe. The side window portion and the core print are formed as integral parts of the same core. 
     In another aspect, a bolster center core has a pair of integral core prints for supporting the core in the mold. The core prints are connected to the core body and correspond with holes in the bolster sidewalls. The prints may, in some embodiments, have stepped surfaces for locating the core with respect to the drag mold. In some additional embodiments, the core print may be used to define part of the bolster center plate or bowl and part of the outside of the casting. 
     In another aspect, the present invention provides one-piece end cores for the bolster. The two ends of each one-piece end core may support the entire weight of the core in the mold, without support chaplets between the core and the drag mold surface. In some embodiments, the one-piece end core may have integral bolt hole pin cores extending out from the top surface for side bearings. 
     In another aspect, the present invention provides a method of making a cast metal sideframe for a railway car truck. The sideframe has front and rear ends and pedestals at each end for mounting on wheelsets. The sideframe also has a top member that extends along a longitudinal axis between the front and rear ends. The sideframe has a tension member that has a bottom center portion and a pair of diagonal portions extending from the bottom center portion toward the pedestals. The sideframe has a bolster opening in the middle of the sideframe between the top member and the bottom center portion of the tension member. The sideframe has a vertical column on each side of the bolster opening. The top member has a top surface with a plurality of lightener openings. The sideframe has interior and exterior surfaces. The method comprises the steps of providing a mold having cope and drag mold surfaces, providing a core having a core outer surface for forming at least a part of the interior surface of the cast metal sideframe, placing the core in the mold, and pouring molten metal into the mold to form the cast metal sideframe. In the improved method of the present invention, the core includes at least one core print and a side window portion. The core print is connected to the core outer surface on a diagonal and corresponds in size, shape and position with one lightener opening to be produced in the diagonal portion of the sideframe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is perspective view of a railway car truck, with sideframes and a bolster. 
     FIG. 2 is a top plan view of a sideframe that may be made according to the present invention. 
     FIG. 3 is a side plan view of a sideframe made according to the present invention with parts shown in section. 
     FIG. 4 is an enlarged partial perspective view of the top member of the sideframe of FIG.  2 . 
     FIG. 5 is a cross-section taken along line  5 — 5  of FIG.  4 . 
     FIG. 6 is a top plan view of the four one-piece sideframe cores of the present invention in place in a drag mold flask with other cores shown for purposes of illustration. 
     FIG. 6A is an enlarged partial cross-section of a portion of a sideframe core received within the cope and drag portions of a mold. 
     FIG. 7 is a perspective view of the four one-piece sideframe cores, showing the portions that are provided to rest against the drag side of the mold surface. 
     FIG. 7A is a partial cross-section of the one-piece end core of FIGS. 6-7, showing the locator boss received in a mating hole in the drag mold surface. 
     FIG. 8 is an exploded perspective view of the four one-piece sideframe cores, showing the opposite side of cores shown in FIG.  7 . 
     FIG. 8A is a partial cross-section of the central opening of the center core of FIGS. 6-8, showing lift arms engaging the core for lifting and moving the core. 
     FIG. 9 is a perspective view of one of the one-piece sideframe end cores of the present invention. 
     FIG. 10 is a partial perspective view of the sideframe bottom center core end of the diagonal tension arm portion of the sideframe end core of FIG.  9 . 
     FIG. 11 is a partial side plan view of one of the core prints of the core of FIG.  9 . 
     FIG. 12 is a perspective view of the bottom center core of FIGS. 6-8. 
     FIG. 13 is an enlarged partial perspective view of one end of the bottom center core of FIG.  12 . 
     FIG. 14 is a perspective view of the sideframe center core shown in FIGS. 6-8. 
     FIG. 15 is a perspective view of some of the multiple prior art sideframe cores replaced by the consolidated one-piece end core of the present invention. 
     FIG. 16 is a perspective view of some of the multiple prior art sideframe cores replaced by the one-piece sideframe center core of the present invention. 
     FIG. 17 is a perspective view of a part of the prior art cores replaced by the one-piece bottom center core of the present invention. 
     FIG. 18 is a partial cross-section of a sideframe made using the cores of the present invention, taken along the longitudinal centerline of the sideframe. 
     FIG. 19 is a partial cross-section of a sideframe made using the cores of the present invention, taken along the longitudinal centerline of the sideframe, showing the opposite side shown in FIG.  18 . 
     FIG. 20 is a partial perspective view of one of the columns, with parts broken away, showing a friction plate in place on one column, with the mounting nuts, bolts and washers shown in exploded view. 
     FIG. 21 is a cross-section taken along line  21 — 21  of FIG.  20 . 
     FIG. 22 is a side plan view of a prior art bolster, with part shown in cross-section. 
     FIG. 22A is a partial top plan view of the prior art bolster of FIG. 22, showing the mounting of a dead lever lug on a flat area of the bolster. 
     FIG. 23 is a side plan view of a bolster made according to the present invention, with part shown in cross-section. 
     FIG. 23A is a partial cross-section of a rib of the bolster of FIG.  23 . 
     FIG. 24 is a top plan view of the bolster of FIG.  23 . 
     FIG. 25 is a perspective view of a prior art core used in making the prior art bolster. 
     FIG. 26 is a perspective view of another prior art core used in making a prior art bolster. 
     FIG. 27 is a perspective view of another prior art core used in making the prior art bolster. 
     FIG. 28 is a perspective view of another group of prior art cores used in making the prior art bolster. 
     FIG. 29 is a perspective view of another group of prior art cores used in making the prior art bolster. 
     FIG. 30 is an exploded side plan view of the three one-piece bolster cores of the present invention. 
     FIG. 31 is a perspective view of the three one-piece cores of the present invention with the two one-piece end cores resting on the one-piece center core. 
     FIG. 32 is a perspective view of an embodiment of a one-piece bolster center core of the present invention. 
     FIG. 33 is a perspective view of another embodiment of a one-piece bolster center core of the present invention. 
     FIG. 34 is a top plan view of the bolster center core of FIG.  32 . 
     FIG. 35 is a cross-section of the bolster center core of FIG. 34, taken along line  35 — 35 . 
     FIG. 35A is a partial cross-section along line  35 A— 35 A of FIG.  34 . 
     FIG. 36 is a perspective view of a one-piece bolster end core of the present invention. 
     FIG. 37 is another perspective view of the one-piece bolster end core of FIG.  36 . 
     FIG. 38 is a perspective view showing the three one-piece bolster cores of the present invention in place in the drag side of a mold flask. 
     FIG. 39 is a partial cross-section showing the position of one of the cores of the present invention relative to the cope and drag parts of a mold. 
     FIG. 40 is a perspective view of the drag side of a core box that may be used to make the sideframe center core. 
     FIG. 41 is a side view of a dead lever lug that may be used with the bolster of the present invention. 
     FIG. 42 is a top plan view of the dead lever lug of FIG.  41 . 
    
    
     DETAILED DESCRIPTION 
     A railway truck  10  that may utilize cast metal components of the present invention is illustrated in FIG.  1 . As there shown, a typical railway truck  10  includes a pair of wheelsets  12 , each wheel set having an axle  14  with a wheel  16  at the end of each axle  14 . The two wheelsets  12  support a pair of spaced, parallel sideframes  18 . The two sideframes  18  have longitudinal centerlines  19  and are spanned by a bolster  20 , which is received in a bolster opening  21  in the middle of each sideframe. The bolster rides on a springset  22 . 
     The present invention provides improved sideframes and bolsters, and methods of making such cast metal bodies, as well as cores to be used in making such cast metal bodies. Use of the method and cores of the present invention should be beneficial in simplifying the making of cast metal sideframes and bolsters, as well as in improving the quality and reducing the weight of such products. The principles of the casting method and core designs should also prove applicable to the production of other cast metal bodies. 
     The sideframes disclosed in U.S. Pat. No. 5,481,986, issued Jan. 9, 1996 to Charles P. Spencer, Franklin S. McKeown and Donald J. Lane and assigned to Amsted Industries Incorporated, Chicago, Ill., may be made in accordance with the principles of the present invention, and the disclosure of that patent is incorporated by reference herein in its entirety. 
     As shown in FIGS. 2-5, a sideframe  18  made in accordance with the present invention generally includes a top member  24  having a center portion  26  and two similar top end portions  28  connected with the center portion  26  through compression member portions  27 . At the front and rear ends  30 ,  32  the sideframe has pedestal jaws or pedestals  34  to be mounted on a wheelset  12  as illustrated in FIG.  1 . Each pedestal includes an outer pedestal leg  29 , a roof  31 , an inner pedestal leg  33  and a journal bracket flange  35 . 
     Each sideframe  18  also includes a tension member or lower member  36  comprised of a bottom center portion  38  and two integral diagonal portions  40  each extending from the bottom center portion  38  toward the pedestals  34 . A spring seat  42  is on the bottom center portion  38  of the tension member  36 , between the bottom center portion  38  and top center portion  26  of the top member  24 . The middle of the sideframe has a lower bolster opening  44  above the spring seat  42  to receive the spring set as shown in FIG.  1 . The middle of the sideframe also has a bolster opening  21  between the lower bolster opening  44  and the top center portion  26  of the top member  24  to receive the end of the bolster  20  as shown in FIG. 1. A column  48  extends between the top member  24  and tension member  36 , along each side of the bolster opening  21  and lower bolster opening  44 . Each sideframe  18  also has two side windows  50 . Each side window  50  is between the bolster opening  21  or columns  48  and the pedestals  34  at the front and rear ends  30 ,  32  of the sideframe  18 , between the end portions  28  of the top member  24  and diagonal arm portions  40  of the tension member  36 . 
     The illustrated sideframe  18  is hollow, with exterior  52  and interior  54  sides or surfaces of its cast metal walls  56 . There are a plurality of openings in the cast metal walls  56 , including lightener openings  58  in the top surfaces of the top member  24 . Other openings  60  are provided, for example, in the walls between the side windows  50  and the diagonal arm portions  40  of the tension member, between the side windows  50  and the top end portions  28  of the top member  24 , and in the lower surface of the center portion  26  of the top member  24 . The walls  56  at each opening have an edge  62 , as shown in FIGS. 4-5, that curves outwardly, that is, the edge  62  is convex. 
     As used herein, references to the “tension member”  36  and “diagonal portions”  40  of the tension member are not intended to include the journal bracket flanges  35  and inner pedestal legs  33 , shown in FIG. 3, unless otherwise noted. 
     As shown in FIG. 5, the illustrated edges have radii of curvature designated “r” and each illustrated edge has two centers of curvature designated “c 1 ” and “c 2 ”. The radii of curvature “r” are about one-half the thickness of the metal walls  56 , represented by the designation “x” in FIG.  5 . The centers of curvature c 1  and c 2  are aligned, with the outermost center of curvature c 1  at a distance less than “x” from the outer surface of the metal and the innermost center of curvature c 2  centered between the outer and inner surfaces of the metal wall. The distance “x” is less than “r” in the illustrated embodiment In the illustrated embodiment, the sideframe walls have thicknesses at the lightener openings of about one-half inch, and the radii of curvature of the edges  62  are about one-quarter inch, with c 1  positioned less than one-quarter inch from the outer surface and c 2  positioned one-quarter inch from the inner and outer surfaces. Alternatively, the cast metal wall could have a single center of curvature, with, for example, a radius of curvature greater than one-half the thickness of the metal, that is, greater than the distance “x” shown in FIG.  5 . 
     The curved edges  62  of the sideframes at the lightener openings  58  and other openings  60  are formed by the method of the present invention, using unique cores  64  having unique core prints  66  as illustrated in FIGS. 6-14. Each core  64  has a core print  66  corresponding with each lightener opening  58 , and other opening  60  in the walls  56  of the sideframe  18  may also have core prints as illustrated. Each core  64  has an outer surface  68  from which the core prints  66  extend outwardly. Each core print  66  includes a core print body  70  to be received in a mating cavity in a mold to produce the cast metal part. Thus, the core print bodies  70  may serve to support and properly position the core in the mold. Each core print body  70  is integral with the remainder of the core and is connected to the core outer surface  68  through a bridge or neck  72 . Each bridge or neck  72  has a thickness, designated “n” in FIG. 11, corresponding with the desired thicknesses of the walls  56  of the cast metal at the edges  62 . Each neck or bridge  72  has a circumference or perimeter that is spaced inward of the edges  73  of the core print that meet or mate with the mold surface. Each neck or bridge  72  forms one of the metal edges  62  in the casting, the inner circumference of the edge  62  being spaced inward from the juncture of the core print and mold so that any fin forming at the juncture of the core print and the mold is spaced from the inner circumference of the edge. Having such a neck or bridge is expected to be beneficial in ensuring that if a fin is formed during the casting process, it should form on the exterior of the casting instead of the interior, making it much simpler to remove the fin through machining or other operation. Moreover, the hole should not fin over and should not form on the edges of the opening which could be stressed, particularly if damaged during fin removal. In the illustrated embodiment the necks or bridges  72  are concave to form convex edges  62 . 
     In making such cores, core boxes having cope and drag portions may generally be used. Such core boxes are generally separated along a parting line to remove the formed core therefrom. To accommodate such removal where the parting line lies in a plane perpendicular to a plane through the centers of curvature of the neck or bridge  72 , the embodiment illustrated in FIG. 11 provides a curved concave neck or bridge with a thickness “n” and with two aligned centers of curvature, designated “c 1 ” and “c 2 ”, each having a radius “r”. The two centers of curvature comprise circles lying outside or beyond a plane  71  through the junctures of the neck  72  and core print body  70 . at the edges  73  of the core prints that meet the mold surface. Alternatively, the bridge  72  could have a single center of curvature and a radius of curvature greater than one-half the thickness of the bridge “n”. With either embodiment, the core neck or bridge does not curve back upon itself in a manner that would interfere with movement of the core relative to the cope and drag parts of the core box. Instead, each juncture  73  is spaced a distance “d” from a plane  75  through the nearest aligned centers of curvature c 1  and c 2 . The distance “d” is equal to the length of the radius of curvature less the distance x. It should be understood that the present invention is not limited to such curvatures; the neck or bridge could alternatively comprise a cylindrical surface, for example. 
     At other locations spaced from the parting line, it is not necessary that the necks or bridges be curved, have two centers of curvature, or have a radius of curvature of the neck greater than one-half the thickness of the neck. Thus, for example, in the cores for forming the bolster of the present invention, the radius of curvature for the necks or bridges may be on the order of one-quarter inch, with the thickness of the neck, between the outer surface of the core body and the core print body being less than about one-half inch to produce a cast metal body having walls with thicknesses of less than about one-half inch. 
     It may be desirable to vary the thickness of the walls of the sideframe, as will be understood by those of skill in the art, to minimize weight while achieving the desired strength. In the illustrated embodiment, the thicknesses of the walls vary, being on the order of about one-half inch in some areas and on the order of about three-quarters of an inch in other areas. The dimensions of the necks or bridges vary according to the desired thicknesses. 
     In the illustrated embodiment the lightener openings in the cast metal sideframe are slightly smaller than those shown in U.S. Pat. No. 5,481,986 to move the openings away from the radius joining the top wall and each sidewall. The illustrated lightener openings  58  in the top member  24  have widths ranging to a maximum of 3.24 inches. The lengths of the two lightener openings nearest the center of the top member are each about six and one-half inches long; each is spaced from the edge by 1.88 inches and from each other by a distance of about two inches. The end lightener hole is spaced 1.62 inches from each edge and does not extend to the outermost part of the outer pedestal leg  29 . However, beading around the openings is removed in using the wrap-around prints so that there should not be any weight gain. 
     Another aspect of the present invention may be seen in FIGS. 6-8, illustrating the core consolidation achieved in the method of the present invention. As there shown, the interior surface  54  of the walls of the sideframe top member, tension member and columns may be made using four cores: two one-piece sideframe end cores  80 , one one-piece sideframe center core  82  and one one-piece bottom center core  84 . 
     Each of the illustrated one-piece end cores  80  of the present invention have a core body  86  with a pedestal portion  88  for defining an interior surface of the sideframe pedestal  34  at the front  30  or rear  32  end of the sideframe. In the illustrated embodiment, the pedestal portion  88  defines the interior surface of the outer pedestal leg  29 ; the one-piece end core also defines the interior surface of the pedestal roof  31 . An integral diagonal tension arm portion  90  serves to define an interior surface of the sideframe&#39;s diagonal portion  40  of the tension member  36 . A top member portion  92  of the one-piece end core  80  also extends from the pedestal portion  88 , and serves to define the interior surface of the top end  28  and compression member  27  portions of the top member  24 . The one-piece end core  80  also includes an integral side window support  94  between the diagonal tension arm portion  90 , the top portion  92 , and a column portion  96 . The side window support  94  serves to define one of the side windows  50  of the sideframe  18 , and as shown in FIG. 9, is connected to the diagonal tension arm portion  90  and top portion  92  of the core through necks or bridges  98  that define the openings  60  in the diagonal portion of the tension arm and underside of the compression portion  27  of the top member  24 . The column portion  96  serves to define the interior surface  54  of the column  48  of the cast sideframe. 
     The side window support  94  has flat surfaces  100  that extend outward beyond the outer surface  68  of the core body  86 . These flat surfaces  100  serve to support a part of the weight of the end core  80  on the mold, and lie in a plane spaced from the outer surface  68  of the core body  86  a distance of about one-half inch. Since this surface  100  on the drag side  102  of the core rests on the drag mold surface  103  of the mold cavity  104 , and since this surface  100  on the cope side  106  bears against the cope mold surface (designated  107  in FIG. 6A for the cope mold surface at the print  70  on the top member portion  92 ), this spacing defines the thickness of the metal to be cast in this area of the sideframe. In the illustrated embodiment, these surfaces  100  on both sides  102 ,  106  of the core lie in planes. 
     In the illustrated embodiment, as shown in FIGS. 7 and 9, the side window support  94  on the drag side  102  of the end core  80  also includes a locator boss  112  extending out from the flat support surface  100 . The locator boss  112  is received within a mating hole or opening  113  (FIG. 7A) in the drag mold surface  103  of the drag side of the mold to locate and support the core. The illustrated locator boss  112  has the shape of a frustum of a cone, that is, it has a slight draft for ease of making the core and ease of placement of the boss  112  in the mating hole  113 . In the illustrated embodiment, as shown in FIG. 6, the cope side  106  of the end core does not have a locator boss, although it should be understood that a cope side locator boss could be provided if desired, along with a mating hole in the cope side of the mold. 
     Each end core  80  is further supported on the drag mold surface  103  by the core prints  66  corresponding with the lightener openings  58  in the outer surface of the top member  24 . Another core print  118  is located at the bottom center core end  120  of the diagonal portion of the tension member. The core print bodies  70  are shaped to be received in mating openings  116  in the drag mold surface  103  and to support a portion of the weight of the end core on the drag mold surface and in mating openings  117  in the cope mold surface  107  (FIG. 6A) to stabilize and position the core with respect to the cope mold surface. The core prints  66 ,  118 , side window supports  94  and locator boss  112  also serve to locate or maintain the position of the end core  80  in the mold during handling and, in combination with the contour of the mold surfaces  103 ,  107 , to define the thickness of the metal to be cast, which may be about one-half inch grade C, B or B+ steel, for example, in the illustrated embodiment. In addition, the combination of the illustrated core prints  66 ,  118  and side window support  94  can support the entire sideframe end core  80  on the drag mold surface  103 , without any support chaplets or other device to support or position the core. 
     The one-piece end cores  80  may be made as a single, integral piece by providing a core box (not shown) having cope and drag halves with surfaces defining the shape of the one-piece end core. As shown in FIGS. 9 and 10, a one-piece end core made with such a core box would have a parting line  130  in the plane of the longitudinal axis  110  of the core but would be free of joint lines. The interior surface  54  of a cast metal sideframe or other metal body would likewise be free from fins, joint lines or other type of witness mark other than a slight depression or witness mark perhaps at the parting line  130  and at the joints between the consolidated cores. As used herein, the expression “witness mark” is intended to be a generic expression encompassing fins and joint marks. 
     To facilitate placement of the one-piece end cores  80  in the mold, the pedestal lug lightener  131  shown in FIG. 15 has been removed from the illustrated one-piece end cores since the presence of the lug lightener interferes with automated setting of the core in the mold. As shown in FIG. 6, the mold may contain a separate core  217  to define the shape of the pedestal opening, and the end core could not be placed in the mold with the core  217  in place if the lug lightener was retained. 
     Another feature of the present invention relates to providing a stepped joint to support and locate the bottom center core  84  on the two end cores  80 , free from any support chaplets or other extraneous device for supporting the weight of the sideframe bottom center core  84 . As shown in FIGS. 8 and 10, the bottom center core end  120  of each diagonal portion of the tension arm has a stepped surface. The stepped surfaces on the end cores include a weight support member  132 , a longitudinal limit member  134  and a lateral limit member  136 , all lying in different planes. As shown in FIG. 12, the two ends  138  of the bottom center core  84  have mating weight support members  140 , longitudinal limit members  142  and lateral limit members  144 , all comprising surfaces lying in different planes. In the illustrated embodiment, the weight support members  132 ,  140  are substantially co-planar with the longitudinal axis  110  of the end cores and bottom center core, although, as will be understood by those in the art, the surfaces  132 ,  140  and others may have a draft in accordance with standard foundry practice, and such draft surfaces are intended to be included within the expression “substantially co-planar” as used herein. The longitudinal limit members  134 ,  142  lie in planes intersecting the longitudinal axis  110  and intersecting the planes of the weight support members  132 ,  140  and lateral limit members  136 ,  144 . The mating lateral limit members  136 ,  144  lie in planes intersecting the planes of the weight support members  132 ,  140  and may comprise a key, designated  137  in the illustrated end core, and keyway, designated  145  in the illustrated bottom center core; it should be understood that the key could be formed on the bottom center core and the keyway on the end core if desired. 
     As shown in FIGS. 6-8, when the end cores  80  and bottom center core  84  are assembled, the bottom center core weight support members  140  rest on and are supported by the end core weight support members  132 , and the bottom center core longitudinal limit members  142  and lateral limit members  144  are positioned by the end core longitudinal limit members  134  and lateral limit members  136 . Thus, the entire weight of the bottom center core  84  is supported by the end cores  80  on their weight support members  132 ,  140  and relative movement between the cores  80 ,  84  is limited by the longitudinal  134 ,  142  and  136 , lateral  144  limit members. The bottom center core  84  has a core print portion  146  at the joint with the end core that mates with the print  118  at the bottom center core end  120  of the diagonal part  40  of the tension member  36 . Thus, the bottom center core may be supported and positioned above the drag mold surface  103  without support chaplets, since the core prints  66 ,  118 ,  146  and locator bosses  112  maintain the position of the end cores  80  and bottom center core  84 , and the mold may be moved and used without the cores shifting position and without using support chaplets or other supports or positioning devices. However, to keep the bottom center core from floating upward during pouring of the molten metal, it may be desirable to place chaplets on top of the bottom center core to bear against the cope mold surface  107  and thereby hold the bottom center core down when molten metal is introduced. 
     As shown in FIGS. 6-7, the junctures of the end cores and bottom center core are at or immediately past the curvature points of the tension members  36 , that is, the junctures are along the diagonal portions  40  of the tension members, near the bottom center portion  40 . 
     As shown in FIGS.  10  and  12 - 13 , the lateral limit surfaces  136 ,  144  of the key and keyway are not perpendicular to the longitudinal limit members  134 ,  142 , but are slightly askew so that the lateral limit surfaces  144  of the bottom center core may be formed substantially parallel to the parting line  143  (FIG. 12) of the bottom center core; the lateral limit surfaces  136 ,  144  may have a draft in accordance with standard foundry practices, and such draft surfaces are intended to be included within the expression “substantially parallel”. This configuration facilitates removal of the bottom center core  84  from the core box. 
     The bottom center core  84  generally defines the shape of the interior surface  54  of the walls  56  of the bottom center portion  38  of the tension member  36  of the sideframe  18 . Openings or slits  147  in the bottom center core, shown in FIG. 12, define internal support ribs  150  in the bottom center portion  38  of the tension member  36 , as shown in FIGS. 18 and 19. Such support ribs  150  are shown in FIGS. 18-19 and extend to the spring seat  42  as illustrated, and correspond with five spaced slits  147  in the bottom center core  84 . In the illustrated embodiment, all of the slits  147  are defined by spaced walls that lie in planes substantially parallel to the plane of the longitudinal axis  149  of the bottom center core  84  for ease of removal of the completed core from the core box. 
     It is generally to be expected that a casting made with the disclosed bottom center cores and end cores will have an internal witness mark corresponding with the junctions of or joints  150 ,  152 ,  156  between the cores. Because of the stepped surfaces at the joints  150 ,  152 ,  156 , these witness marks are longitudinally offset on the interior surfaces  54  of the walls  56  in the casting. Thus, considering the two sides of the casting defined by the plane of the longitudinal centerline  19  of the cast sideframe  18 , shown in FIGS. 18-19, the distances between the witness marks  152  and the transverse centerline  154  on one side of the longitudinal centerline  19  of the sideframe are greater than the distances between the witness marks  156  and the transverse centerline  154  on the opposite half of the casting. As shown in FIGS. 18 and 19, a casting having such offset witness marks  152 ,  156  can be expected to have been made using cores with stepped surfaces at the joints between cores. 
     A one-piece sideframe center core  82  is illustrated in FIG.  14 . This core may generally be as described and shown in U.S. Pat. No. 5,481,986, although in the center core of the embodiment illustrated in the present application, the sideframe center core  82  and bottom center core  84  are separate elements rather than combined as disclosed in the issued patent. In addition, in the embodiment illustrated in FIG. 14, the column faces do not have lightener openings, but merely openings for bolts for connecting friction plates to the column faces. 
     The one-piece sideframe center core  82  of the embodiment illustrated in FIG. 14 includes a bolster opening element or portion  158  corresponding with the bolster opening  21  in the cast sideframe  18 . The center core has a central longitudinal axis  159 . The bolster opening portion includes a pair of planar support print surfaces  160  that lie in planes substantially parallel to the longitudinal axis  159  of the center core and substantially parallel to the longitudinal axes  110  of the end cores  80  when combined with the end cores as shown in FIG.  6 . The planar support print surfaces  160  may rest on mating support print surfaces of the drag mold surface  103  to support a part of the weight of the center core on the mold and prevent molten metal flow into the area to become the bolster opening. At the ends of the two planar support print surfaces  160  are opposite column surfaces  162  which define the exterior side of the opposing faces  163  of the sideframe columns  48 . The core column surfaces  162  are substantially parallel to each other and have vertically aligned cylindrical elements  164  extending outwardly from the surfaces with parallel axes aligned along the core&#39;s longitudinal centerline  159 . These cylindrical elements comprise integral bolt hole pin cores. As shown in FIG. 6, when the center core  82  is combined with the two end cores  80 , the cylindrical elements or bolt hole pin cores  164  meet the column portions  96  of the end cores to define bolt holes  166  in the opposing faces of the columns  48  of the cast metal sideframes for attachment of friction plates to the columns as shown in FIG.  19 . 
     As shown in FIG. 14, the illustrated one-piece sideframe center core  82  includes an integral spring seat element or portion  170  to define the lower bolster opening  44  and top surface of the spring seat  42  in the sideframe. The bottom surface  172  of the spring seat element  170  is spaced above the bottom center core  84 , and together with mating surfaces  174  in the drag and cope mold surfaces  103 ,  107 , define a cavity in which metal is cast to form the spring seat  42 . The spring seat element  170  also has planar support surfaces  176  which support a part of the weight of the center core element  82  on the drag mold surface  103  and mate with the cope mold surface  107  to assure proper positioning of the center core with respect to the mold surfaces. 
     The illustrated one-piece sideframe center core  82  also includes a top member center portion  178  that defines the interior surface  54  of the walls  56  comprising the center portion  26  of the top member  24 . Integral necks or bridges  180  join the top member center portion  178  of the center core  82  to the bolster opening portion  158 . The necks or bridges  180  correspond with openings  182  in the underside of the center portion  26  of the top member  24 , as shown in FIG.  3 . 
     The illustrated one-piece sideframe center core  82  may be made as a single integral piece by providing a core box with cope and drag portions surfaces defining the shape of the center core. The core may be made so that the longitudinal axis  159  comprises the parting line of the core box, with the resulting core being free from joints and having only a parting line  184  along its central longitudinal axis  159 . To produce any indentations or protrusions in the core body that could be damaged during removal from the core box, the core box may be provided with movable parts that can be retracted when the core is to be removed from the core box. Such a core box is illustrated in FIG.  40 . Automatic devices, such as pneumatic or hydraulic operated elements, may be used with the core boxes to move the movable parts as desired during the cycle. The core produced may only have a visible parting line on a portion of the core, such as along the central longitudinal axis  159  of the top member center portion  178  and necks or bridges  180  but not elsewhere. 
     A cast metal sideframe made using the illustrated sideframe center core  82  may be expected to have witness marks comprising either joint lines or fins  186  on the interior surface  54  of the walls  56  comprising the top member  24 , as shown in FIGS. 18 and 19, where the center core top member center portion  178  portion meets the end core top member portions  92 , as shown in FIGS. 6-8, but to be otherwise free of joint lines or fins in the areas of the sideframe defined by the center core  82 . In addition, the center core  82  may be supported on the drag mold surface  103  solely by the support surfaces  160 ,  176  so that the cast metal in the area of the sideframe defined by the one-piece center core  82  has fewer chaplets; since there are no support chaplets, one side of the tension member bottom center  40  may be free from support chaplets, while the other side may have some location chaplets. 
     The one-piece sideframe center core  82  may also have gates  161  in the bolster opening element or portion  158 , for movement of molten metal as will be understood by those in the art. The illustrated gates are included for purposes of illustration only and, if included, should be sized, shaped and positioned according to standard casting practices. 
     A cast metal sideframe made using the four illustrated cores  80 ,  82 ,  84  may be expected to have witness marks  186  on the interior surface  54  of the walls  56  comprising the top member  24 , as shown in FIGS. 17 and 18, and the offset interior witness marks  152 ,  156  in the tension member  36 , but the interior surface should be otherwise free of joint lines and fins in the areas of the sideframe defined by the center core  82 . 
     The advantages of using two such one-piece end cores  80 , one-piece center core  82  and one-piece bottom center core  84  can be seen from a comparison of the number of cores used in the prior art to produce the interior cavity of a sideframe. Prior art cores are illustrated in FIGS. 15-17. FIG. 15 shows a typical prior art core arrangement for making an end of a sideframe; seven cores were needed to form each end of the sideframe, for a total of fourteen cores, compared to a total of two cores in the present invention. The prior art cores for the sideframe end included: cope and drag side frame window cores  190 ,  192  to form the area of the side window  50  and column  48  interior; cope and drag side frame intermediate cores  194 ,  196  to form a part of the top member and pedestal roof interior; cope and drag sideframe tension cores  198 ,  200  to form the diagonal portions  40  of the tension member  36 ; and an end core  202  to form the interior of a part of the pedestal  34 . These cores were not integral, but were juxtaposed or sometimes adhered together, with joint lines existing between each of the individual cores. This substantial number of cores used in the prior art has been problematic in several respects: automation of the process of setting the cores in the mold is difficult since there are several small pieces that need to fit together in the mold; and there could be quality control problems with the prior art cores: shifts and movements of the individual cores or imperfections in the fit between adjoining cores could produce interior fins during casting or could result in the varying thicknesses of the casting walls; and if two cores such as the cores  198 ,  200  are not properly aligned, the metal casting may have a stepped or uneven surface at the juncture of the two parts. Multiple cores are often thin, requiring use of core rods to provide strength to the core. Removal of these core rods after the casting is formed adds to the cost of manufacture. 
     Similar disadvantages and problems arise in using the multiple cores for the prior art center portion of the sideframe. As shown in FIGS. 16-17, one example of prior art center cores generally required at least nine cores where the present invention provides two: a side frame bolster opening core  204 , four column pin cores  206  inserted into the bolster opening core, a spring seat core  208  and cope and drag bottom center cores  210 ,  212  adhered together. The prior art also typically included a spring seat back up core (not shown) that was not integral with or adhered to another core. 
     It should be understood that several additional cores are required for adding various appendages to the sideframe although those other cores will not be addressed by this invention. For example, there may be separate rotation lug cores added to the center core, although such cores could also be consolidated into the sideframe center core. Moreover, an additional six cores (not shown) may be required in the manufacturing process. But even with these additional cores, the present invention consolidates twenty-three cores into four, reducing the total number of cores for making a sideframe from twenty-nine to ten. These additional cores may need to be supported by chaplets on the drag mold surface, and may require locator chaplets to secure their positions. Some of these additional cores that are used with the present invention are generally shown in FIG. 6, including the right and left journal cores  217  and right and left journal bracket cores  219 . In addition, bracket cores to form slots for brake beams on the inboard sides of the sideframes would still be used, and the right and left journal cores, right and left journal bracket cores and brake beam bracket cores may require use of weight-supporting or locating chaplets, so that the resulting sideframe would have some chaplets, although the number of chaplets and the problems associates with their use is greatly decreased with the present invention. 
     Thus, it can be seen that the present invention offers several advantages in making sideframes. By reducing the number of cores, any tendency for shifting of the multiple cores is reduced, reducing internal metal mismatches. The safeguard against shifting is enhanced in the present invention by the use of the locator bosses  112  on the end cores  80  and the stepped connections between the bottom center core  84  and the end cores that limit lateral and longitudinal movement. Similarly, the fit of the core prints  66  of the end cores in the mating areas of the cope and drag mold also stabilize the positions of the end cores and bottom center core. And since the four cores of the present invention are supported in the mold by the core prints, other cores and opening-defining parts, the castings can be made without support chaplets, increasing the efficiency of the manufacturing operation and minimizing the chance for shifting of the cores. In addition, the present invention minimizes the number of joint lines which normally result between the faces of multiple cores, to improve the appearance of the final casting, reducing the amount of preparatory or finishing work necessary to remove fins, and improving internal casting quality by eliminating or greatly reducing the potential for stress risers which tend to form along the entire joint line. And since the manpower required for proper placement of the four cores instead of twenty-three is substantially less, labor costs should be reduced. With fewer and larger cores, there is also a chance for automation of the assembly process. Moreover, as will be understood by those in the casting field, the tooling costs in creating a single mold, as well as the replacement and maintenance costs for retaining quality standards for each mold is substantial. It is expected that waste of mold sand will also be reduced with fewer cores being produced, further reducing costs. In addition, it is expected that with fewer cores and less relative motion between cores, there is a lower potential for sand particles to become dislodged and become inclusions in the finally-cast metal. Inclusions can potentially become stress concentration areas or simply result in an area on the casting that requires surface clean up. Another advantage of the present invention is in eliminating or reducing the need to use core rods to strengthen the cores, simplifying production and reducing costs. 
     Another advantage of the present invention is in the assurance of proper placement and alignment of core pieces. In the case of the one-piece center core  82 , the vertically aligned cylindrical elements  164  take the place of the column pin cores  206 . The column pin cores  206  have typically been inserted into the surface of the side frame bolster opening core  204  after the cores  204 ,  206  have been formed, and there has been a potential for misalignment of the pin cores, resulting in bolt holes  166  in the final casting that may be angled, making it more difficult to insert a bolt through the hole. With the integral cylindrical elements  164 , the resulting bolt holes should always be properly aligned. 
     Another feature of the present invention relates to provision of a pair of radial drafts  220  on the end core column portions  96  as shown in FIG.  9 . As illustrated in FIG. 20, the facing exterior faces  163  of the columns  48  typically have bolt holes  166  for mounting friction plates  222  to the sideframe with bolts  224 . As shown in FIG. 21, washers  226  and nuts  228  are tightened against the interior surface  54  of the column portion of the sideframe. If the interior surface  54  of the column is uneven, irregular or offset, then less than the entire flange of the nut or washer contacts the surface  54 ; during tightening, stresses could be concentrated at portions of the nut, resulting in breaking or bending of the nut or bolt, or a less than desirable clamping force holding the plates  222  in place. This problem could potentially occur in one-piece end cores having parting lines running through the bolt hole areas, as well as in multi-piece cores having separate cores adhered to or juxtaposed with each other at junctures or joints intersecting the bolt hole areas. To alleviate this potential problem, the present invention provides a pair of conical raised areas  220  on the column portions  96  of the end cores  80 . As shown in FIG. 9, each raised area  220  comprises a raised center  230  extending furthest out from the outer surface  68  of the surrounding planar face  232  of the column portion  96  core. Each raised area also includes a tapered surface  234  extending from the raised center  230  toward the outer surface  68  of the planar face  232 . The raised area has a circular outer periphery  235  that is spaced slightly above the planar face  232 . The outer diameter of each raised area is about two and one-half inches. The tapered surface  234  and center  230  are shaped as a cone. The angle of the illustrated tapered surface is small, being on the order of one-third to one-half degree. In the illustrated embodiment, there are two vertically-aligned raised areas  220 , and the parting line  110  of the core runs through the raised centers  230  of the two raised areas. When placed in the mold along with the other cores, the center of each raised area  230  of each end core contacts the free end of one of the vertically aligned cylindrical elements  164  to define the bolt holes  166  in the casting. Thus, as shown in FIG. 21, each bolt hole  166  in the casting is surrounded by a depression  236  in the interior  54  surface of the casting. The depression  236  has a circular edge  238  at or slightly below the interior surface  54  of the casting, and a tapered wall  240  extending between the edge  238  and the bolt hole  166  at the center of the depression. In use, the peripheral edge of the nut  228  or washer  226  should contact the tapered wall  240  of the depression around the entire circumference or perimeter of the nut or washer. Since the entire circumference of the nut or washer is in contact with the interior surface of the side frame, there should be no bending moment on the nut and no lessening of the clamping force or torque. Instead, use of the present invention should result in symmetrical loading of the washer and nut. It should be understood that the principle of this feature of the invention should be applicable to any setting where a bolted connection is to be made where there is also a core or mold parting or joint line intersecting the site for the bolted connection. It should also be understood that the slope of the tapered surfaces of the core raised area and casting may generally be relatively small. 
     Many of the above principles can be applied to improve hollow cast metal bolsters  20  as well. As shown in FIGS. 30-31, a bolster  20  can be made with three consolidated cores defining its interior: a one-piece center core  300  and two one-piece end cores  302  supported on the center core  300 . Other standard cores, such as two spring cores, four pocket cores and a top center pin core, would still be required to be used to complete the bolster. 
     The bolster  20 , as shown in FIGS. 23 and 24, has a center  304 , two outboard ends  306 , a top wall  308 , and parallel side walls  310  extending down from the top wall  308 . Each illustrated side wall  310  has four large, spaced holes  312 , and each hole has an overall length and width. The bolster has an interior and the top wall  308  has an interior surface  314  and an exterior surface  316 . The side walls  310  also have interior surfaces  318  and exterior surfaces  320 . The bolster  20  has a central longitudinal axis  322  running from one outboard end  306  to the opposite one, and a central transverse axis  324 . The bolster  20  also has a bottom wall  326  and interior walls  328 . The bottom wall  326  in the illustrated embodiment extends between the sidewalls  310 , and can have openings or holes (not shown) communicating with the interior of the bolster. 
     The bolster  20  also has a center bore  330  through the top wall  308 . The central longitudinal axis  322  and central transverse axis  324  intersect at the center bore  330 . Two sets of bolt holes  331  are provided for mounting side bearings to the bolsters. 
     Within the interior of the illustrated embodiment of a bolster, there are longitudinal ribs  328  extending longitudinally between the interior surface  314  of the top wall  308  and the bottom wall  326 , and transverse support ribs  334  extending transversely between the longitudinal ribs  328 . 
     As shown in FIGS. 23-24, each longitudinal rib  328  has opposite faces  336 ,  338 , and each transverse rib  334  has opposite faces  340 ,  342 . In the illustrated embodiment, at least one of each pair of faces  336 ,  338 ,  340 ,  342  is generally perpendicular to the plane of the top wall  308  of the bolster and remains generally perpendicular to that wall throughout its entire height. Similarly, the faces  340 ,  342  of the illustrated transverse ribs  334  are generally parallel to the transverse axis or plane  324  throughout their entire height, from the interior surface  314  of the top wall  308  to the interior surface  344  of the bottom wall  326 . At least one of the opposite faces  336 ,  338  of the longitudinal ribs  328  is generally parallel to the central longitudinal axis or plane  322  throughout its entire length. The central longitudinal axis  322  and transverse axis  324  lie in vertical planes, and at least one of the illustrated opposite faces  336 ,  338 ,  340 ,  342  of the longitudinal ribs  328  and transverse ribs  334  is generally vertical throughout its entire length. 
     In contrast, in the prior art bolster illustrated in FIG. 22, the transverse support ribs  346  had faces  348 ,  350  that were both angled throughout a portion of their heights. These faces  348 ,  350  were both in non-vertical planes that intersected the vertical plane of the central transverse axis  324 . These angled transverse ribs  346  prohibited making a one-piece center core for the bolster, since such a core could not be removed from the core box without damage to the core. Instead, multiple cores, as shown in FIG. 28, were needed to produce the central portion of the bolster. 
     In this aspect of the present invention, all of the interior transverse rib faces have been aligned to allow a one-piece core to be made and used without sacrificing the desired physical characteristics of the bolster. Although the interior ribs may thin or thicken between the top and bottom walls, the change is on one side of the parting line for the one piece core, and only one face of the wall changes direction on that side of the parting line. And while the interior ribs made with a one piece core may have draft faces, on each side of the parting line the faces do not diverge from a vertical plane in the same direction. Thus, as shown in FIGS. 23 and 23A, in the top portion  337  of the bolster, from the top wall  308  down, the faces  336 ,  338 ,  340 ,  342  of the longitudinal and transverse ribs do not diverge in the same direction from a vertical plane  341  between them and parallel to one of the longitudinal or transverse axes or planes  322 ,  324 , and in the bottom portion  339  of the bolster, up from the bottom wall  326  to the top portion, the faces  336 ,  338 ,  340 ,  342  of the longitudinal and transverse ribs do not diverge in the same direction from a vertical plane between them and parallel to one of the longitudinal or transverse axes or planes  322 ,  324 . The top and bottom portions  337 ,  339  are defined by a line  343 , shown in FIG. 23A, corresponding with the parting line  406  of the center core used to make the bolster, shown in FIG.  30 . 
     The multiple prior art cores needed to produce a prior art bolster are illustrated in FIGS. 25-29. As shown in FIG. 29, two sets of cope and drag end cores  360 ,  362  were required to make the central part of the bolster, joined along a joint line  364 . Right and left collar cores  366 , shown in FIG. 25, were needed to form the center bowl or plate  368  (shown in FIG.  22 ). An additional lug core  370 , shown in FIG. 26, was used to form lug holes in the side wall for attachment of a brake beam dead lever lug to the bolster. Two sets of cope  372  and drag  374  center cores, shown in FIG.  28 . These center cores  372 ,  374  were also joined along joint lines  376 . As in the case of the sideframe cores, these cores were supported on the drag mold surface by chaplets. Thus, there was a potential for shifting of the cores, and control of the thicknesses of the metal walls became problematic. In addition, with all of the joint lines, there was a potential for stress risers to form in the casting. 
     As shown in FIG. 27, the prior art also used four separate pin cores  378  to be attached to the cope parts  360  of the end cores to form holes  331  for attachment of side bearings to the bolster. There was the potential for the pin cores  378  to be attached off-axis, creating the potential for undesirable stress on the bolts for attaching the side bearings to the bolsters. 
     In this aspect of the present invention, these sixteen prior art cores have been consolidated into three cores, shown in FIGS. 30-39. In both the embodiments of FIGS. 32 and 33, the one-piece center core  300  has a center core body  380  to be received in a mold cavity for defining the interior surfaces  314 ,  318 ,  344  of parts of the top  308 , side  310  and bottom  326  walls of the bolster, as well as parts of the longitudinal ribs  328  and transverse ribs  334 . The center core body  380  has a central longitudinal axis  382  and a central transverse axis  383 , as well as outer surfaces  384  to define the interior surface  318  of the sidewalls  310 . Outboard of the outer surfaces  384  are two core prints  386 . The core prints  386  are integral with the center core body  380 , and serve to support and position the center core in the drag mold  387  so that no support chaplets are required. The inner surfaces  455  of the core prints (FIGS. 34,  35 ) also serve to define a portion of the exterior surfaces  320  of the bolster sidewalls  310 . Spaced surfaces  381  (FIG. 39) in the receiving mold also define portions of the exterior surfaces of these sidewalls. The core prints  386  are connected to the center core body  380  through necks or bridges  388  corresponding in size, shape and position with the holes  312  in the sidewalls. 
     The center core body  380  and center core prints  386  have lengths sufficient to span across the widths of all of the necks or bridges  388  on one side of the center core body. The center core prints  386  have heights sufficient to span across the heights of all the necks or bridges  388  on the center core body  380 . In the illustrated embodiments, the core print heights are also great enough to extend to a pair of holes  390  (FIGS. 31-33) in the print and aligned with holes in the core body  380  to receive cylindrical cores to define the dead lever lug holes. The heights of the core prints vary with the heights of the adjacent necks or bridges across the lengths of the core prints. 
     As shown, each embodiment of the core prints  386  has a central zone  392  and two end zones  394 . The central zone  392  and end zones  394  have stepped top surfaces  396  and stepped bottom surfaces  398 , and the heights of the central zones  392  of both embodiments are greater than the heights of the end zones  394 . 
     The central zones  392  of both core prints  386  have a height great enough and are wide enough to form part of the center plate or bowl  393  (FIGS. 23,  24 ) of the bolster. As shown, the center plate forming parts  400  are integral with the core prints  386 . At the core prints&#39; end zones  394 , the top surfaces  396  and bottom surfaces  398  are stepped toward each other, away from the top and bottom surfaces at the central zone. The top surface  396  may have also two steps, as shown in FIG. 33, or a single step as shown in FIG.  32 . In either embodiment the different levels of the top and bottom surfaces may be joined by angled or draft surfaces  402  that ease removal of the bolster center core from the core box. The drag  387  and cope  403  mold surfaces are formed to have recesses that mate with the shapes of the core prints so that the core prints may be easily placed in the mold. 
     The bottom surfaces  398  of the core prints  386  comprise weight support surfaces parallel with the top surfaces of the core prints. The total surface areas of the two weight support surfaces of the core prints and mating surfaces of the drag mold surface are great enough to support the entire center core on the drag mold surface  387  free from support chaplets. The weight support surfaces lie in planes that intersect the longitudinal axis  382  of the center core. The draft surfaces  402  of the core prints and mating surfaces of the cope mold may comprise positioning surfaces that lie in planes intersecting the top surfaces and bottom surfaces  396 ,  398  of the core prints. The draft surfaces  402  may thus serve to limit longitudinal movement of the core body  380  in the mold. The end faces  407  of the core prints, received against mating faces in the drag mold, may also serve to limit longitudinal movement of the center core. The outer surfaces  404  of the core prints and mating surfaces in the drag mold perpendicular to the top  396 , bottom  398  and draft  402  surfaces may control lateral movement of the center core with respect to the drag mold portion  387 . 
     The one-piece center core  300  is free from joint lines, but has a parting line  406  with segments that intersect the vertical plane of the central transverse axis  382 ,  383 . The center core body  380  has a top portion  408  on one side of the parting line  406  and a bottom portion  409  on the opposite side of the parting line  406 . As shown in FIGS. 32 and 33, the parting line  406  does not intersect the end faces  407  of the core, since it is preferred that the end faces  407  not have a draft above the parting line that would create a gap in the mold. Instead, the parting line goes to the top surface  396  of the end zone at the end face  407  and then down again. 
     The center core body  380  has a plurality of interior surfaces  412 , with pairs of them spaced apart to define slits for forming the longitudinal ribs  328  and transverse ribs  334  of the bolster  20 . As shown in FIGS. 34 and 35, to facilitate removal of the core from the core box, no two adjacent surfaces on one side of the parting line  406  diverge from a vertical plane parallel to the transverse or longitudinal axis  382 ,  383  in the same direction; this design allows the core to be made in one-piece with a cope and drag core box pulled apart on the parting line  406 . 
     As will be understood by those in the art, the interior surfaces  412  of the bolster center core may have drafts to facilitate removal of the core from the core box. However, the core will not have back drafts that would be damaged in removing the core from the core box if, as shown in FIG. 35A, no two adjacent surfaces  412  on one side of the parting line  406  diverge in the same direction from a vertical plane  401  between them and parallel to one of the longitudinal or transverse axes  382 ,  383  of the core. 
     The necks or bridges  388  connecting the core body and the core prints  386  may be concave curves, like the necks or bridges for the embodiment of the sideframe end cores illustrated in FIG. 11, so that the resulting bolster has convex surfaces at the edges surrounding the holes  312 . As in the sideframe end cores, as shown in FIG. 35 the bolster core necks  388  may comprise inwardly curved surfaces with one or more centers of curvature designated “c” lying in a line around the exterior of the neck or bridge, beyond the junctures  411  of the necks and prints, as in FIG. 11 embodiment for the sideframe. As in the sideframes, the thicknesses of the necks  388  correspond with the desired thickness of the walls of the cast bolster in that area. As in the sideframe, the radius of curvature may be greater than or equal to one-half the thickness of the neck or bridge. In the illustrated embodiment, the radius of curvature of the necks is less than one-half the thickness “n” of the necks, being about three-sixteenths of an inch for a metal thickness of one-half inch to meet the adjoining draft surfaces of the core print interior  455  and core body exterior  384 . 
     As shown in FIG. 22A, prior art bolsters frequently used a flat raised mounting area  457  on the exterior of the sidewall  461  for mounting a dead lever lug  463  to the bolster. Such flat raised mounting areas have provided a level mounting for the dead lever lugs, that is, for the mounting bracket for the railcar braking mechanism, in an area where the sidewall is angled. However, to provide such a flat raised mounting area on a bolster made with a one-piece center core is problematic: to avoid creating a step which would prohibit removing the one piece core from the core box, the mounting area would have to extend to the parting line, but this would add to the weight of the casting. Instead, in the present invention, the area of the bolster sidewall  310  where the dead lever lug is to be mounted does not have a flat mounting area; the area of the bolster sidewall is instead angled, as seen in FIG. 24, and the dead lever lug is similarly angled for mounting on the bolster sidewall, as shown in FIGS. 41 and 42. 
     As shown in FIGS. 41 and 42, a dead lever lug  413  for use with the illustrated bolster has two arms  415 ,  417  angled to mate with the angle of the bolster sidewall. The illustrated dead lever lug arms  415 ,  417  are spaced apart with a gap  419  between them. The gap  419  spans the radius on the bolster sidewall where the sidewall is angled. The arms  415 ,  417  may also be angled in another direction to mate with any draft in the sidewall. 
     In another aspect, the one-piece center core  300  for the bolster may have two stepped outboard ends  414 ,  416  opposite from the transverse center line  383  for supporting the end cores  302 . Each of the two outboard ends  414 ,  416  of the bolster has a weight support member  418 , a longitudinal limit member  420 , and a lateral limit member  422  all lying in different planes. As shown in FIGS.  30  and  35 - 36 , the two inboard ends  424  of the end cores  302  have mating weight support members  426 , longitudinal limit members  428  and lateral limit members  430 , all comprising surfaces lying in different planes. In the illustrated embodiment, the weight support members or surfaces  418 ,  426  are perpendicular to the planes of the longitudinal axis  382  of the core body. The mating longitudinal limit members  420 ,  428  lie in planes parallel to the plane of the transverse center line  383  and the mating lateral limit members  422 ,  430  lie in planes parallel to the longitudinal axis  382  of the core body. The mating lateral limit members  422 ,  430  may comprise a key at each end  414 ,  416  of the center core and a mating keyway in the ends  424  of the end cores, as shown in FIGS. 31-34 and  36 - 37 . 
     As shown in FIGS. 30-31 and  38 , when the three cores  300 ,  302  are assembled the interior or inboard ends  424  of the end cores  302  are supported by the outboard ends  414 ,  416  of the one-piece center core  300 . Each end core  302  also has an outboard end  432  that rests on and is supported by a part of the drag mold surface  387  when the three cores are placed in a mold. The drag mold  387  and outboard ends  432  of the end cores may have mating surfaces to ensure proper placement of the cores in the mold and the cope mold may also have mating surfaces to stabilize the positions of the outboard ends  432  of the two end cores. As shown in FIG. 38, gating or gas relief cores  433  may also be provided at the outboard ends  432  of the end cores. With the end cores  302  thus supported and the center core  300  supported solely by the core prints  386 , all three cores may be supported above the drag mold surface free from support chaplets. In the illustrated embodiment, the top surfaces  396  of the end zones  394  are flush with the top surface  431  of the drag mold  387  so that the bottom surface of the cope mold may bear against the end zones  396  and hold down the core. 
     The end cores  302  may each be a one-piece integral core free from joint lines as illustrated in FIGS. 36 and 37. The end cores may have recessed areas  434  for forming the parts of the bolsters that ride on friction shoes on the sideframes, and as will be understood by those skilled in the art, the shape of the end cores will vary with the type of friction shoe to be used. As shown in FIG. 38, mating friction shoe cores  435  may be provided on the drag mold surface. In addition, as shown in FIG. 38, a center pin core  429  may also be provided at the center of the bolster center core. In each end core, parallel interior surfaces  436  define a central slit  438  along a central longitudinal axis  439  for forming one of the longitudinal ribs  328  of the bolster. Additional slits  437  are formed by parallel surfaces  439  at the inboard ends  424  of the end cores  302  and align with interior surfaces  412  of the bolster center core to form two additional longitudinal ribs  328 . Each end core  302  may have a parting line  440  but is free from any joint line. 
     Each end core  302  also has a pair of integral bolt hole cylinders  442  extending upwardly from the top surface  444  of the end core. The bolt hole cylinders are aligned transversely near the stepped inboard ends  424  of the end cores to provide the holes  331  for bolts for mounting side bearings to the bolster. 
     A bolster resulting from using the three cores of this aspect of the present invention can be expected to have a minimum number of interior fins or joint lines. The only interior fins or joint lines can be expected to be along the junctures of the center core  300  and end cores  302 . Any such fin or joint line is referred to herein generically as a witness mark. As shown in FIG. 23, there may be a pair of top witness marks  446  on the interior surface  314  of the top wall  308 , parts of the top witness marks  446  being perpendicular to the longitudinal axis  322 , part matching the shape of the key and keyway, and positioned between the center bore  330  and the side bearing bolt holes  331 . The interior surface  318  of each side wall  310  may have a pair of side witness marks  448  leading from the ends of the top witness marks  446  to the bottom wall  326  interior surface  344 . Each of the side witness marks  448  comprises a step-shaped line having a segment  450  parallel to the top wall interior surface  314  between two segments  452  perpendicular to the top wall interior surface  314 . A pair of spaced straight bottom witness marks  454  may extend across the interior surface  344  of the bottom wall  326  between the side witness marks  448  on opposite side walls. All of the witness marks correspond with the junctures of the mating ends  414 ,  416 ,  424  of the center core  300  and two end cores  302 . The interior surfaces of the walls of the bolster are otherwise free from joint lines and fins. All of the walls of the bolster may be expected to be free from support chaplets, although there may be chaplets to prevent flotation of the end cores during casting, and possibly to position a center core forming the center bore  330 . 
     The exterior sidewalls  310  of a bolster made in accordance with this part of the disclosure is defined in part by the interior surfaces  455  of the center core prints (FIGS. 34,  35 ) and may be expected to bear some imprint of the perimeters of the core prints  386  on the exterior surfaces  320  of the side walls  310 . Thus, the elongated “plus” sign shape of the core prints  386  may be visible on the exterior of the casting as a witness mark. 
     The cores described above may be used to produce cast metal sideframes and bolsters by placing the cores in suitable drag molds formed of green sand or other material in the drag side of a flask. A suitable cope side of a flask may then be placed on the combination of the cores and drag flask. 
     For the sideframes, chaplets may be used to prevent floatation of the bottom center core and to support and locate other cores, such as the cores used to form recesses on the inboard sides of the sideframes to receive the ends of brake beams, the journal cores and other cores to cooperate with the one-piece end cores to form the complete pedestals  34 . Such other cores are illustrated generally in FIG. 6, showing the four cores of the present invention in position in a drag flask; the details of the other cores are not shown, as those cores may be made and used according to the prior art. 
     For the bolster, the one-piece bolster center core  300  may be supported against movement in all three directions without chaplets, being supported by the mating mold halves and core prints. Each of the two bolster end cores  302  may be supported at one end by the stepped and keyed joint with the center core, and the other end supported by the drag mold. While the bolster end cores do not need support chaplets, floatation chaplets may be provided to hold the end cores down during pouring. Pouring and venting areas will be provided according to standard foundry practices. 
     The combinations may be handled as has been done traditionally in the art, and in fact may be moved with a reduced chance for the cores to shift position. Molten metal may be introduced as has been done in the past. After the metal has cooled, the casting may be removed from the flask, and the cores may be removed from the flask using known methods, such as by shaking the casting. The casting may then be finished, either as has been done traditionally in metal casting operations or the finishing operation may be automated since any fins will have been moved to the exterior of the casting. The present invention includes the method of making cast steel sideframes, bolsters, and other cast metal bodies in accordance with known foundry principles, using the new cores as described, and preferably without support chaplets for the one-piece cores. Standard grades of steel for such products may be used in these processes. 
     The cores may generally be made in accordance with standard foundry practices. Generally, cope and drag core box portions may be provided, and if automated equipment, such as a blower, is used to fill the core boxes, the cope and drag portions may be provided with a plurality of vents for air escape during filling. The sand used to make the cores may be mixed with a known binding agent. A suitable binder system is available from the Foundry Products Division, Ashland Chemical Company division of Ashland Oil, Inc. of Columbus, Ohio. The binder is sold under the trademark “ISOCURE” and comprises two resins: a first part with having phenolformadehyde polymer blended with solvents and a second part having polymeric MDI (methylene bis-phenylisocyanate). The two liquid resins cure to a solid urethane resin. Generally, the phenolic resin first part combines with the polyisocyanate second part in the presence of an amine catalyst (triethylamine) to form the solid urethane. Mixing the resins with the sand should be as recommended by the manufacturer, and should follow standard practices, taking into account the quality of the original sand, whether the sand is fresh or recycled, and other factors. The binder ratio and binder percentage may be adjusted as recommended by the manufacturer. The core boxes for producing the cores may have vents placed and sized as recommended by the manufacturer. It should be understood that the present invention is not limited to any particular binder system, nor to any particular core box design or device for introducing the sand and binder mixture into the core boxes. 
     Standard industry practices for introducing the mixture of sand and binder may be used, including but not limited to blowing. As will be understood by those skilled in the art, any suitable commercially available equipment may be used for introducing the mixture and curing agent, if any, as well as any improvement in presently available equipment. The equipment should be compatible with the binder system, but otherwise the selection of equipment may vary depending on desired production schedules. 
     For the blower device used, the blow tube size and position will vary with the core. Blow tubes may be located above the deepest and heaviest sections of the core, with blow tube diameters varying in accordance with standard practice. A blow plate for the center core  82  may have a plurality of conduits with rubber ends for introducing the sand and binder mixture into the core box. The cope and drag portions of the core boxes will have vent areas through which air may escape as the sand and binder mixture is blown into the core box and through which the catalyst gas may escape. The position, number and areas of the vents should be according to standard practice and as recommended by the manufacturers or suppliers of the binder and catalyst and blower equipment. 
     In making a one-piece core such as the illustrated one-piece center core  82  for the sideframe, traditional cope and drag core boxes may not produce the desired design that has recesses or protrusions that would interfere with pulling the two core box halves apart and removing the core. With such cores, it may be necessary to use a core box such as the drag portion illustrated in FIG.  40 . As there shown, the core drag box  459  has movable walls  460 ,  462 ,  464  that may be moved inward during core production and then pulled outward during core removal, and a stationary wall  466  that is part of the drag. Thus, features such as the vertically-aligned cylindrical elements  164  may be formed by cylindrical recesses  468  in the movable side walls  460 ,  464  and pulled out of the way when the completed core is to be removed from the box. Instead of moving the entire wall, it may also be desirable to have portions that move at different times during production. The walls or portions of walls may be moved by devices such as a pneumatic control  470 ; in the illustrated embodiment, two pneumatic controls are provided, with lines  472  connected to power the controls  470  to move the walls  460 ,  462 ,  464  or portions of walls. Recesses in the core box walls may be provided with vents  473 , and as will be understood by those in the art, any equipment used to introduce the sand and binder mixture into the core box should be designed to ensure that all parts of the core box are filled with the sand and binder mixture. Some movable parts may also be needed in producing the one-piece bolster center core with holes; axially movable cylinders may be used to produce the holes  390  through the prints and later filled with cylindrical cores. 
     The one-piece cores produced in accordance with the principles disclosed herein may be expected to weigh a substantial amount and accordingly be difficult for a single worker to manipulate. Accordingly, it may be desirable to provide for automation in removing the cores from the core box and in transporting the cores. In addition, pallets may be provided to support the cores. Picker fingers or lift devices may be incorporated into the core box design to lift the core out of the box, and gantries may be provided for standard moving devices to lift and move the cores. The core designs may be modified to accommodate the particular lifting and moving devices and pallets to avoid damage to the surfaces of the core bodies. For example, it may be desirable to make the core prints large enough for a lifting or supporting device to bear against several portions of the cores instead of acting against the core body itself. And it may also be desirable to provide orifices or recesses in the core prints and core bodies to receive lifting devices for moving the cores as well as to lighten the cores and reduce the amount of sand and binder required to be used. As with the lifting devices, storing and moving devices selected may vary depending on many factors, the illustrated cores may be varied to accommodate the equipment available or selected. 
     Examples of variations in the core design to accommodate lifting and moving devices are illustrated in FIGS. 6-8A,  14  and  30 . As shown in FIG. 30, for example, each core print  386  on the bolster center core  300  may have a pair of recesses  500  defining a shelf  502  for receiving the end of a lifting device. As shown in FIGS. 6-8A and  14 , the sideframe center core  82  may have an central opening  504  with an interior shelf  506  as shown in FIG. 8A; thus, a group of lifting arms  508  can be used, each rotating about its central longitudinal axis  510 , with a perpendicular segment  512  that rotates to fit under the interior shelf  506  so that the core may be lifted. The lifting devices may then be rotated so that the perpendicular segments are no longer under the shelf when the core is deposited in its proper position on the drag mold, for example. Preferably, the lifting devices contact the cores in areas such as the prints to avoid harming the cores. 
     It should be understood that standard foundry practices should be used along with the disclosures of the present invention, such as providing chill plates where necessary for the best quality casting. It should also be understood that the illustrated cores do not necessarily show recesses to form the chill plates, and the absence of chill plates or recesses in a drawing should not be considered as a teaching that none are necessary or desirable. Similarly, where slits are shown in cores that may correspond with chill plates generally, it should be understood that the positions of the chill plates may be other than as shown, as the drawings are merely illustrative of such features. 
     Standard foundry practices may be used in washing and drying the cores. In accordance with standard foundry practices, various surfaces such as the longitudinal and lateral limit surfaces of the sideframe end, center and bottom center cores and bolster center and end cores, and various walls and ribs may have slight drafts incorporated into the design to facilitate removal of the cores from the core boxes. 
     For handling the finished cores in, for example, transferring the core from the core-making site to the site where the cores are placed in the mold, it may be desirable to provide pallets that are capable of supporting the combined cores. 
     While only specific embodiments of the invention have been described and shown, it is apparent that various alternatives and modifications can be made thereto. For example, although the cores have been shown shaped to produce particular railway truck parts, it should be understood that changes in shapes may be made for other types of railway trucks, and the invention is not limited to the illustrated style of railway truck. In addition, although the invention has been described with respect to particular core structures for producing railcar truck parts, the principles of the invention may be applied to the production of other cast metal structures. It is, therefore, the intention in the appended claims to cover all such modifications and alternatives as may fall within the true scope of the invention.