RAIL SEAT FOR RAILWAY LATERAL FRAME AND METHOD FOR MAKING IT BACKGROUND OF THE INVENTION Rail freight wagons are usually configured in three-piece assemblies consisting of a pair of lateral chassis (lateral frames) laterally separated, a crossbar that is It extends between the side chassis, and a pair of sets of wheels located at opposite ends of the side chassis. Each side frame includes a cross-member opening centrally located to receive the end of a cross member extending laterally between and perpendicular to the side frames. The ends of the side frames are laterally aligned to receive a set of wheel axles which is usually called the pedestal jaw of the side frame. Examples of typical railroad cars are shown in U.S. Patent No. 4,363,276; 4,838,174; 5,718,177; and 6,125,767. A typical side frame comprises an elongated upper compression member extending in a longitudinal direction parallel to the rail of the rail. The side frame also comprises two diagonally extending tension members extending generally downward at an acute angle from almost the ends of the upper compression member. A lower limb extends
lengthwise and join the lower ends of the diagonal tension members. The column members generally extend vertically between the lower member and the upper compression member from a point near the union of the diagonal tension members and the lower member. Such column members form the opening of the crossbar in the lateral chassis. A portion or upper face of the base member of a side frame is usually referred to as a spring seat of the side frame, since it is adapted to receive the spring play on which the ends of the cross member are supported. The crosspiece extends laterally between each lateral chassis with the ends of the crosspiece extending into the openings of the crosspiece where it is supported on sets of springs. The spring seat includes a vertical structure, commonly referred to as a spring retainer, for positioning and supporting springs of the spring set. An example of a known spring retainer is shown in Figure 2. Another example of a known spring retainer 2 is shown in Figures 3-5. As can be seen, the retainers 1,2 generally comprise vertical flanges formed on the upper face of the spring seat 3,4. As shown in Figures 3 and 4, the spring seat 3 may also include depressions or recesses 5 for receiving the lower faces of the springs. The dotted lines 6 arched
in Figure 3 they generally represent the springs of the spring set. In order to reduce the overall weight of the rail car, many of the components, such as the side chassis, are formed as hollow metal castings. Examples of the processes for melting such components can be found in U.S. Patent Nos. 5,481,986 and No. 5,752,564. As described in the '564 patent, such castings are created using molds consisting of sand cores supported between upper and false frame molding portions. The upper and false frame portions define a mold cavity. The sand hearts are supported within the mold cavity and used to form the hollow and open spaces in the castings. The sand hearts are manufactured in a sample box of the upper and false frame portions. The heart box is filled, for example, by means of a bellows, with a mixture of sand and a binder. The mixture is then treated to sufficiently harden the resulting sand core to allow it to be used to mold the cast component, i.e., the side chassis. As will be appreciated, the resulting hearts have a negative image of the casting. Problems may arise during the manufacture of
The sand hearts that are used to form these previous spring seats and spring retainers. Specifically, as can be seen in Figures 2-5, the prior spring detents 1,2 present abrupt vertical surfaces that are generally perpendicular to the flow of the sand during the creation of the sand cores. These vertical faces cause the sand to vortex as it is blown into the mold, thus creating an empty core in the sand and corresponding defects in the molten metal component. The present invention addresses several aspects of these problems in the prior art. Certain aspects of one embodiment of the present invention relate to an improved cast metal side frame for use in a rail car. The side chassis has a spring seat to support the springs of a set of springs. The side frame is molded using a heart that includes a portion to define the outer surface of the spring seat. The spring seat includes a plurality of aerodynamically shaped spring retainers formed in the spring seat. The aerodynamic shape of the spring retainers reduces the tendency to form gaps in the sand cores that are used to fuse the side chassis. The spring retainer can have a top face
concave, which reduces the volume of the material comprising the spring retainer. It is beneficial to reduce the volume of the material to reduce shrinkage during cooling of the lateral chassis, thus reducing the tendency to separation, cuts and fractures that form on the upper surface of the spring retainer. The aerodynamic shape can include forming sidewall portions of the detent at an obtuse angle with the upper surface of the spring seat. In one embodiment, the spring seat has an outer end, an inner end and an upper face. The spring retainer may include a first face facing the outer end of the spring seat and a second face facing the inner end of the spring seat. The first and second faces of the spring retainer preferably form obtuse angles with respect to the upper face of the spring seat. The first and second faces are generally transverse to the direction in which the sand flows during the formation of the sand cores that are used to mold the lateral chassis. As a result, the tendency of the sand to vortex and create voids during the formation of sand hearts is reduced. The spring retainers may include arched side walls to interconnect and support the
springs of a set of springs. The arcuate recesses can be formed on the upper face of the spring seat, adjacent the arcuate side walls, to receive the lower faces of the springs. Another aspect of the present invention relates to a method for manufacturing hollow molded metal side frames of the type having a spring seat to support the springs of a set of springs. The method comprises the steps of providing a heart to define the interior hollow of the lateral chassis, providing a mold with portions of upper and false frame and upper and false frame mold surfaces defining a mold cavity, placing the heart in the cavity of the mold, pour molten metal into the mold to form a cast part of the side chassis, remove the cast part from the mold, and separate the cast part from the heart. The heart comprises a spring seat portion for defining the outer surface of the spring seat such that the outer surface of the spring seat includes a plurality of aerodynamically shaped spring retainers formed in the spring seat, wherein the shape aerodynamics of the spring retainers reduces the tendency to form gaps in the spring seat portion of the heart. Another aspect of the present invention relates to
with a method for manufacturing hollow cast metal side chassis of the type having a spring seat to support the springs of a set of springs. The spring seat has an outer end, an inner end and an upper surface. The method comprises the steps of providing a heart to define the interior hollow of the lateral chassis, providing a mold with portions of upper and false frame and upper and false frame surfaces of mold defining a mold cavity, placing the heart in the cavity of the mold, pour molten metal into the mold to form a cast part of the side chassis, remove the cast part from the mold, and separate the cast part from the heart. The heart comprises a spring seat portion for defining the outer surface of the spring seat such that the outer surface of the spring seat includes a plurality of aerodynamically shaped spring retainers formed in the spring seat, wherein each retainer of aerodynamically shaped spring has a respective first face facing towards the outer end of the spring seat and a respective second face facing towards the inner end of the spring seat, and wherein the first and second faces of the retainer of spring preferably form obtuse angles with respect to the upper face of the spring seat, wherein the aerodynamic shape of the detent
The spring reduces the tendency for voids to occur in the spring seat portion of the heart. Another aspect of the present invention relates to a method for manufacturing hollow molded metal side frames of the type having a spring seat to support the springs of a set of springs. The method comprises the steps of providing a heart to define the interior hollow of the lateral chassis, providing a mold with portions of upper and false frame and upper and false frame surfaces of mold defining a mold cavity, placing the heart in the cavity of the mold, pour molten metal into the mold to form a casting of lateral chassis, remove the casting from the mold, and separate the casting from the heart, where the heart improvement comprises: a spring seat portion to define the outer surface of the spring seat such that the outer surface of the spring seat includes a plurality of spring detents 1 formed in the spring seat, at least some of the spring retainers have concave upper faces, wherein the volume of the material comprising the retainer, Another aspect of the present invention relates to an improved cast metal side chassis of the ti It has a spring seat to support the springs of a set of springs. The spring seat comprises one
plurality of spring detents formed on an upper face of the spring seat. At least some of the spring detents have concave upper faces, wherein the volume of the material comprising the retainer is reduced. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a railway car, with side chassis and a crossbar. Figure 2 illustrates a spring seat of the prior art that includes a plurality of spring detents. Figure 3 is a top plan view of another spring seat of the prior art employing an alternative design spring retainer. Figure 4 is a perspective view of one of the spring detents of Figure 3. Figure 5 is a view illustrating the formation of a sand core for molding the spring retainer of Figure 4. Figure 6 is a top plan view of the side frame of Figure 1. Figure "7 is a side plan view of the side frame of Figure 6. Figure 8 is an enlarged partial perspective view of the top member of the side frame of Figure
Figure 9 is a top plan view of four one-piece side chassis cores that can be used to form the side chassis, showing the hearts in place in a molding box with other cores. Figure 9A is an enlarged partial transverse sectional view of a portion of a lateral frame core received within the upper and false frame portions of a mold. Figure 10 is a perspective view of the four one-piece side frame hearts, showing the portions provided to lie against the side of the upper frame of the mold surface. Figure 10A is a partial transverse sectional view of the one-piece end heart of Figures 9-10. Figure 11 is an exploded perspective view of the four one-piece side chassis hearts, showing the opposite side of the hearts shown in Figure 10. Figure 12 is a perspective view of the center heart of the side chassis ] shown in Figures 9-10. Figure 13 illustrates a spring seat according to certain aspects of one embodiment of the present
invention Figure 14 is a top plan view of a portion of the spring seat of Figure 13. Figure 15 is a perspective view of the spring retainer of the spring seat of Figure 13. Figure 16 is a top view in the spring retainer plant of Figure 15. Figure 17 is a front plan view of the spring retainer of Figure 15. Figure 18 is a rear plan view of the spring retainer of Figure 15. Figure 19 is a transverse sectional view along line AA of Figure 16, illustrating the formation of a sand core for molding the spring retainer. The present summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the preferred embodiments of the present invention, modalities that are currently preferable are shown in the drawings. It should be understood, however, that the present invention is not limited in the configurations and instrumentalities shown in the accompanying drawings.
In Figure 1 a rail car 10 is illustrated which can utilize a molten spring seat according to certain aspects of one embodiment of the present invention. Except for what was explained above, the rail car 10 can be constructed generally in accordance with the wagons described in the North American Patent Nc. 5,481,986, issued January 9, 1996 to Spencer et al., And entitled "Lightweight Truck Side Frame" "(Patent 986) and US Patent No. 5,752,564, issued May 19, 1998 to Callahan et al. ., and entitled "Railway Truck Casting and Ethod and Cores for Making Casting" (Patent '' '564) The description of the' 986 patent and the '564 patent has been incorporated herein by reference in its entirety. As shown in Figure 1, a rail car 10 typically includes a pair of wheel sets 12. Each wheel set 12 has an axle 14 with wheels 16 at the ends of each axle 14. The two wheel sets 12 support a pair of parallel and spaced side chassis 18 The two side chassis 18 have longitudinal center lines 19 and are connected by means of a cross member 20, which is received in a cross member opening 21 (see Figure 7) in the middle of each lateral chassis The ends of the crossbar 20 are supported on the ab cross-sections 21 of the crossbar by means of sets 22 of springs.
As shown in Figures 6-8, the side chassis 18 generally includes an upper member 24 or compression member having a central portion 26 and two similar upper end portions 28 connected to the central portion 26 through the portions 27 of the compression member. The pedestal jaw 34 that is formed at the ends 3032, front and rear of the side chassis is configured to be mounted on a set 12 of wheels, as illustrated in Figure 1. Each side chassis 18 also includes a tension member or lower member 36 comprising a lower central portion 38 and two 40 diagonal integral portions. Each of the diagonal lower portions 40 extends from the lower central portion 38 towards the pedestals 34. A spring seat 42 is provided in the lower central portion 38 of the tension member 36, between the lower central portion 38 and the 26 upper central portion. As discussed above and as shown in Figure 1, half of the crossbar opening 21 of the side chassis above the spring seat 42 is sized to receive the set of springs and the end of the cross member 20. The columns 48 extend between the upper member 24 and the tension member 36, along each side of the opening 21 of the cross member. Each side frame 18 also has two side windows 50.
The illustrated side frame 18 is hollow, with lateral or exterior surfaces 52 and inner 54 of its walls 56 of molten metal. The side chassis 18 may include a plurality of openings in the molten metal walls 56 that include the lightening openings 58 in the upper surfaces of the upper member 24. As shown in Figures 9-11, and as described in great detail in the "564 patent, the interior surface 54 of the walls of the upper member of the side frame, the tension member and the columns can be manufactured using four cores of sand, particularly, two end cores 80 of the one-piece side chassis, a central heart 82 of the one-piece side chassis and a central core 84 of the one-piece side chassis.The cores are placed in a mold cavity defined by upper and false molding frame portions The outer surface of the lateral frame is defined by means of the upper frame and molding portions, which provide a negative image of this surface Each of the one-piece end cores 80 which are illustrated has a heart body 86 with a pedestal portion 88 to define an interior surface of the pedestal 34 of the side chassis at the front end 30 or end 32 ior of the side chassis. In a modality
illustrated, the pedestal portion 88 defines the inner surface of the outer leg of the pedestal jaw 34, the one-piece end heart also defines the inner surface of the pedestal jaw of the ceiling. An integral diagonal tension arm portion 90 serves to define an interior surface of the diagonal portion 40 of the side frame of the tension member 36. A portion 92 of the upper member of the one-piece end heart 80 also extends from the pedestal portion 88, and serves to define the inner surface of the upper end 28 and the portions of the compression member 27 of the member 24. higher. The one-piece end core 80 also includes an integral side window support 94 between the diagonal tension arm portion 90, the upper portion 92, and a column portion 96. The side window support 94 serves to define one of the side windows 50 of the side chassis 18, and connects to the diagonal tension arm portion 90 and to the top portion 92 of the heart through neck or bridges (not shown) that define the openings (not shown) in the diagonal portion of the tension arm and the underside of the compression portion 27 of the upper member 24. The column portion 96 serves to define the interior surface 54 of the column 48 of the cast side frame. A side window support 94 has surfaces
100 flat that extend outward beyond the outer surface 68 of the heart body 86. These flat surfaces 100 serve to support a part of the weight of the end heart 80 in the mold, and lie in a plane separated from the outer surface 68 of the heart body 86 at a distance of about 1.27 cm (one-half inch). Because this surface 100 on the side 102 of the false molding rests on the false-molding surface 103 of the mold cavity 104, and because the surface 100 on the side 106 of the upper frame is supported against the surface of the upper frame of the mold (designated 107 in Figure 9A for the upper frame surface of the mold in the print 70 on the portion 92 of the upper member), this space defines the thickness of the metal to be melted in this area of the side frame . In the illustrated embodiment, these surfaces 100 on both sides 102, 106 of the heart lie in planes. As shown in Figure 10, the side window support 94 on the false side 102 of the end heart 80 also includes an indicator ridge 112 extending outwardly from the flat support surface 100. The indicator ridge 112 is received within an orifice or aperture 113 matched (Figure 10A) on the false molding surface 103 on the side of the mold to place and support the heart. The flange 112 indicator
illustrated is in the shape of a truncated cone, that is, it has a slight outline for making the heart and facilitating the placement of the flange 112 in the matched hole 113. In the illustrated embodiment, as shown in Figure 9, the side 106 of the upper frame of the end heart does not have an indicator flange, although it should be understood that a side marker flange of the upper frame could be provided, if desired , together with an orifice rigged on the side of the upper frame of the mold. Each end heart 80 is furthermore supported on the false molding surface 103 by means of the impressions 66 of the upper frame corresponding to the lightening apertures 58 on the outer surface of the upper member 24. Another heart impression 118 is located at the end 120 of the lower central heart of the diagonal portion of the tension member. The heart impression bodies 70 are formed to be received in the openings 116 assembled in the false molding surface 103 and to support a portion of the weight of the end heart on the false molding surface and in the openings 117 matched therein. upper mold frame surface 107 (Figure 9?) to stabilize and position the core with respect to the upper mold frame surface. The impressions 66, 118 of the heart, the side window supports 94 and the indicator ridge 112 also serve
to position or maintain the position of the end heart 80 in the mold during handling, and in combination with the contour of the molding surfaces 103, 107 to define the thickness of the metal to be cast, which may be approximately 1.27. inches inch) steel grade + B or B, C, for example in the illustrated mode. In addition, the combination of the illustrated heart impressions 66, 118 and the side window support 94 can support the end heart 80 of the complete side frame in the
false molding surface 103, without support pins or other support devices or placement of the heart. As shown in Figure 12, the heart of the side frame center 82 of an illustrated piece includes an integral spring seat member or portion 170 for
define the lower cross member opening and the upper surface of the spring seat 42 in the side chassis 18. The lower surface 172 of the spring seat member 170 is separated above the lower central core 84, and together with the mated surfaces on the surfaces 103,
107 of false and upper molding frame define a cavity in which the metal melts to form the spring seat 42. The spring seat member 170 also has flat support surfaces 176 that support a weighing portion of the center heart element 82 on the surface
103 of false molding and paired with surface 107
of the upper molding frame to ensure proper placement of the center core with respect to the mold surfaces. The hearts described above can be used to produce side chassis of molten metal by placing the hearts in suitable false molds formed of green sand or other material on the false side of a mold box. One side of the upper frame of a molding box can then be placed on top of the combination of the hearts and the false of the molding box. Supporting cores can be used to prevent the floating of the lower central core and to support and position other cores, such as the hearts used to form recesses in the inner sides of the side chassis to mislead the ends of the oscillating braking levers, the bearing hearts and other hearts to cooperate with the one-piece end hearts to form the complete pedestal clamp 34. Such other hearts are generally illustrated in Figure 9, showing the four hearts in position in a false of a molding box; the details of other hearts are not shown, since those hearts can be manufactured and used according to the prior art. The combinations can be handled as has been
traditionally performed in the art, and can actually move with a reduced opportunity for hearts to change position. The molten metal can be introduced as it has been done in the past. After the metal has cooled, the casting can be removed from the casting box, and the hearts can be removed from the casting box using known methods, such as shaking the casting. The cast part can then be finished, either as it has traditionally been done in the metal casting operations or in the finishing operations can be automated because any fin will have moved from the outside of the casting. The present invention includes the method of making molten steel side chassis, cross members and other bodies of molten metal in accordance with known casting principles, using the new cores as described, and preferably without support cores for the cores in one piece. Standard grades of steel can be used for such products in this process. The cores can usually be manufactured according to standard casting practices. Generally, the upper and false frame portions of the heart can be provided, and if automated equipment, such as a bellows, is used to fill the heart boxes, the upper and false frame portions can be provided with
a plurality of ducts for exhausting the air during filling. The sand used to make the hearts can be mixed with a known binder. 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 contains a polymer of phenol formadeido mixed with solvents and a second part having poremeric MDI (bispheni 1 and methylene socianate). The two liquid resins cure a solid urethane resin. Generally, the first part of the phenolic resin combines with the second part of the polyisocyanate in the presence of an amine catalyst (triethylamine) to form the solid urethane. Mixing resins with sand should be done as recommended by the manufacturer, and standardized practices should be followed, taking into account the quality of the original sand, whether the sand is recent or recycled, and other factors. The ratio of the binder to the percentage of the binder can be adjusted as recommended by the manufacturer. Heart boxes can produce hearts that can have ducts placed and sized as recommended by the manufacturer. It is to be understood that the present invention is not limited by any particular binder system, nor by any design or box device.
heart to introduce the mixture of binder and sand into the heart boxes. Standard industry practices for introducing the mixture of sand and binder can be used, including but not limited to blowing. As will be understood by those skilled in the art, any commercially available suitable equipment may be used to introduce the mixture and curing agent, if any, as well as any improvement in the equipment currently available. The equipment must be compatible with the binder system, but otherwise the selection of equipment may vary depending on the production programs desired. For the use of the bellows device, the size and position of the blow tube may vary with the heart. The blow tubes can be located above the deepest and heaviest sections of the heart, with the diameters of the blow tube varying in accordance with standard practice. A blow plate for the central heart 82 can have a plurality of ducts with rubber ends to introduce the binder and sand mixture into the heart box. The upper and false frame portions of the heart boxes will have ventilation areas through which air can escape when the binder mixture and sand are blown into the heart box and through which the catalyst gas
can escape The position, number and areas of the ventilations must be in accordance with standard practice and as recommended by the manufacturers or distributors of the binder and the catalyst and blowing equipment. In the fabrication of a one-piece heart such as the center heart 82 of a one-piece side chassis that is illustrated, traditional upper and false frame heart boxes may not produce the desired design having recesses and protrusions that would interfere with the design. moment to pull the two false halves of the heart to separate them and remove the heart. With such hearts, it may be necessary to use a heart box such as the fake portion illustrated in Figure 40 of the '564 patent. Figures 13-20 illustrate certain aspects of a spring seat 200 according to a specific embodiment of the present invention. The spring seat 20C is used in place of the spring seat 42 described above. The rest of the lateral chases 18 'may be constructed generally as described above. The spring seat 200 includes a plurality of aerodynamically shaped spring retainers extending upwardly from its upper face 220. The spring detents 202 are configured to position and support the springs 203 of the spring seat 22 in the spring seat 200. The springs are usually represented by
means of dotted lines in the form of an arc in Figure 14. In the illustrated embodiment, the spring seat 200 is configured to support the six springs 203. For this purpose, the spring seat 200 includes four of the 5 spring detents 202 of aerodynamic shape, which are placed centrally in the spring seat 200. The spring seat 200 also includes a plurality of other spring retainers 204, 206, 208 located around the periphery of the spring seat 200. Some or all of these
spring detents 204, 206, 208 may also incorporate an aerodynamic design, see, for example, the seal 208 which has a front face 209 that forms an obtuse angle with the top face 220 of the spring seat. Arched depressions or recesses 210 are formed in the upper face of the
spring seat, adjacent the spring retainers 202, 204, 206, 204, to receive the lower faces of the springs 203. With reference to Figures 14 and 16, the spring retainer 202 has a first end 212 and a second extreme
214. The ends 212 and 214 have respective first and second faces 216, 218 that form obtuse angles 217, 219 with the upper face 220 of the spring seat 200. For example, the first and second faces 216, 218 can each form an angle of approximately 120 ° with the face
220 top of spring seat 200. The angle 217, 219
it can be the same for both sides 216, 218, or alternatively, the faces 216, 218 can form different angles with the upper face 220. In the illustrated embodiment, the spring retainer 202 is asymmetrical when viewed from the top, see, for example, Figures 14 and 16. Specifically, the first end 212 is narrower than the second end 214. Alternatively, the detents of spring could have a symmetrical shape. In the illustrated embodiment, two of the spring detents 202 (i.e., the lower spring retainers in Figure 13 and the retainer 202 on the left side of Figure 14) have their first narrower ends 212 which faces toward the outer end 222 of the spring seat 200, wherein the other two spring retainers 202 (ie, the spring retainers 202 in the upper portion of Figure 13 and the catch 202 on the right hand side of Figure 14) have their first ends 212 which faces towards the inner end 224 of the spring retainer 200. Alternatively, the spring detents 202 could all face in the same direction. For example, all of the spring detents 202 could have their first face facing the outer end 222 of the spring seat 200. Each of the spring detents 202 includes four arcuate side walls or faces 226. (See
Figure 16) The faces 226 are positioned to engage and support different springs of the springs 203 when the set 22 of springs is mounted on the spring seat 200. The recesses 210 are formed adjacent the arched faces 226. The aerodynamic shape of the spring retainer 202 reduces the tendency to form voids in the sand cores that are used to mold the side chassis 18 'of molten metal. Specifically, as shown in Figure 20, the incorporation of obtuse angles 217, 219 between the first and second faces 216,218 and the upper face 220, as they oppose the angles perpendicular to these sites in the detents 1, 2 of Prior spring, allows the sand mixture to flow smoothly through the mold during sand core formation. As a result of the aerodynamic design and the smooth contours of the retainer 202, there is a lesser tendency for the sand to form vortices as it passes over the portion of the mold defined by the retainer 202. As a result, there is a lower tendency to form voids in the heart of sand. The spring retainer 202 may be in the order of
1. 905 centimeters (3/4 inch) and preferably have a concave upper face 228. By forming the retainer 202 with the concave upper face 228 reduces the volume of the material comprising the retainer 202. Reducing the volume of the material is beneficial in reducing shrinkage during the cooling of the material.
chassis 18 'of molten metal, thus reducing the tendency for separations, cuts and fractures that are formed in the upper surface of the spring retainer 202. Alternately, the spring retainer 202 may be formed with a flat top as illustrated, by the dashed line, in Figure 19. Although the invention has been described with reference to a specific embodiment, those skilled in the art will understand that Various changes and equivalences can be made that could be substituted without departing from the scope of the invention. Additionally, many modifications can be made to adapt to a particular situation or material for the teachings of the invention without departing from its scope. For example, although the invention has been described in the context of the formation of spring detents, it will be appreciated that the principles of the invention can also be applied to the production of other molten metal structures. Therefore, it is intended that the invention is not limited to the particular embodiment described, but that the invention will include all modalities that fall within the scope of the invention.