Use of no-bake mold process to manufacture railroad couplers.

Institute

Mexican Property

Industrial i

_SE_ «« MU 1 «a®M3Mfo '« s ·'

PATENT TITLE NO. 339159

Headlines):

Address:

Denomination:

Classification:

Inventor (s):

BEDLOE INDUSTRIES LLC

2711 Centerville Road, Suite 300, PMB # 8033, Wilmington, Delaware, 19808, USA

USE OF A NO-BAKE MOLDING PROCESS TO MAKE RAILWAY COUPLERS. lnt.CI.8: B61G3 / 04

F. ANDREW NIBOUAR; JERRY R. SMEREOKY: RONALD P. SELLBERG; ARTHURA.®BSAUT

<img file="MX339159B_D0001.tif" />

i »;

* MX / a / 2014/012161

Intern filing date January 5, 2011

Divisional Patent Number: 324299

Country

US

PRIORITY • '• V

Date:

January 2010

Number:

12/685,346

Validity: Twenty: years

Due Date: 5 of i. The reference patent is granted coiFundamei _ «·» «i»: fj A i

In accordance with article 23 of the Law of the fool from the date of presentation of rights.

out of 2031

<img file="MX339159B_D0002.tif" />

2nd fraction V, β ° fraction III, and 59 of the Industrial Property Law.

This patent has a validity of twenty years Non-derogable, at and will be subject to the payment of the fee to keep the

Whoever signs this title does so with Industnal property (Official Day of the Federation (O.

1/01/2004. 16/06/2005. »/01/2006,1(6/05/2009,06/01/2010,

a), subsection iii) ^¿ and 12th frafions I and III of the Rules Meffl j on 07/01/2002, i / 07/2004&gt; 07/08/2004 and 09/07/2007); articles

Deputies, Coordinator, Divisional Directors, Heads of the Departmental Offices and other subordinates of the Mexican Institute of Industrial Property. (DOF 07/29/2004, 08/04/2004 and 09/13/2007).

or articles 6 ° fraoeionee 19 and 7 ° bis 2 of the | Signed on 08/02/1994, 2010/1996, 12/26/1997, 1 | 10, r7 "TSQ42y" 194/2012); Articles 1, 3, Industrial Law (DOF 1 | 'rtciso a), subsection iii), 16 sections and and of '05 / 1999, action V 12/1999, is I and III and

Regionals, Divisional Deputy Directors, Coordinators 12/15/1999, amended on 02/04/2000,

Issue Date: May 13, 2016

DIVISIONAL DEPUTY DIRECTOR OF EXAMINATION OF THE PATENT BACKGROUND, MECHANICAL, ELECTRICAL AND INDUSTRIAL DESIGN RECORDS AND

<img file="MX339159B_D0003.tif" />

Arenas No. 550, Floor 1,

Coi. Santa María Tepepan town. XochirnHco. CP 16020,

Mexico City

Tel. (55) 53 34 07 00 www irnpi rrtó.nix

<img file="MX339159B_D0004.tif" />

<img file="MX339159B_D0005.tif" />

MX / 2016/37546

Wxl ClUoH I Ό IZI-6 J

USING A FORMING PROCESS WITHOUT KOjRJá &amp; ARFABRICATING RES COUPLERS

Field of Invention

The present embodiments relate generally to the field of railroad couplers, and more specifically, to the fabrication of railroad couplers and their various parts through the use of no-bake or air-set casting.

Background of the Invention

Sand casting is one of the first forms of casting. Its use is very popular due to its low cost and the simplicity of the materials involved. A sand cast or welded sand cast is a casting produced by the following process: (1) placing a pattern in the sand to create a mold, incorporating a filling system, (2) removing the pattern , (3) filling the mold cavity with molten metal, (4) allowing the metal to cool; (5) breaking the sand mold and removing the casting, and (6) finishing the casting, which may include repair by welding, polishing, machining, and / or heat treating operations. This process is now explained in more detail.

In sand molding, the main piece of equipment is the mold, which contains various components. The mold is divided into two halves: the front (upper half

<img file="MX339159B_D0006.tif" />

INSTITUTO MEXICANO (lower half), who meet along WW¡ separation. The sand mixture is compacted by forming a master pattern, forming a mold cavity, which is an impression of the shape to be cast. The sand is generally housed in what specialists call jars, which are boxes without a bottom or lid, which are used to contain the sand. The sand mix; it can be rammed down as it is added and / or the final mold assembly is sometimes vibrated to compact the sand and fill in unwanted voids in the mold. The sand can be compacted by hand, but machines using pressure or impact ensure a more uniform compaction of the sand and require much less time, thus increasing the production rate. The pattern is removed, leaving the mold cavity. The cores are added as required, and the front is placed on top of the drag.

The cores are additional pieces that make up the interior openings, voids, and runways. The cores are typically composed of sand so that they can be shaken out of I? casting, rather than requiring the necessary geometry to slide out. As a result, sand cores allow the creation of many complex internal features. Each core is placed in the mold before the molten metal is poured.

The gaps in the pattern called prints each core in its place. However, the nuclei ^

INDUSTRIAL * slipping, due to poor fit between the core and the

<img file="MX339159B_D0007.tif" />

core impressions, metal flow around the core, or due to buoyancy in molten metal.

Small metal pieces called garlands are fixed between the cores and the; cavity surface to provide additional support for the cores. The garlands are small metal pieces that are fixed between the core and the surface of the cavity. The garlands consist of a metal with a higher melting temperature than the metal being cast in order to maintain its structure to support the core. After solidification, the garlands are thrown into the laundry and excess garland material that protrudes is cut off.

In addition to the external and internal characteristics of the casting, other characteristics must be incorporated into the

I:

mold to accommodate the flow of molten metal, the molten metal is poured into a pouring pot, which is a large depression at the top of the sand mold. The metal funnels come out of the lower part of this depression and down the main channel, called the sprue. The sprue connects to a series of channels, called runners, that carry the molten metal into the cavity. At the end of each corridor, molten metal enters the cavity through

<img file="MX339159B_D0008.tif" />

The chambers called outlet tubes that are filled

with molten metal are often connected to the corridor system. The outlet tubes provide an additional source of metal during solidification. As the casting cools, molten metal shrinks and additional material in the gate and outlet tubes act to refill the cavities as needed. The open outlet tubes also aid in shrinkage reduction. When using open outlet tubes, the first material to enter the grade is allowed to pass completely through the cavity and into the open outlet tube. This strategy prevents early solidification of the molten metal and provides a source of material to compensate for the shrinkage. Finally, small channels are included that run from the cavity to the outside of the mold. These channels act as vents to allow gases to escape from the cavity. The porosity of the sand also allows some air to escape, but sometimes vents are needed. Molten metal flowing through all channels (sprue, runners, and pipes of i

outlet) will solidify attached to the casting and should be

I separated from the part after it is removed. The metal

I molten is poured into the mold cavity, and after cooled and solidified, the casting is separated from the mole

<img file="MX339159B_D0009.tif" />

The precision of the casting is limited to 9 ¥ $ 'f £, ¥ féf £ 93 of sand and the molding process. Green coarse sand castings impart a rough texture to the surface of the part, making them easy to distinguish from parts made by other processes. Air-set or no-bake molds can produce parts with much more uniform surfaces. The benefit of providing a smoother surface is discussed in more detail below, but is not insignificant in improving the performance of castings made using the air-set casting process. After molding, the casting is covered in a residue of oxides, silicates, and other compounds. This residue can be removed by various means, such as polishing or shot blasting. Several other benefits of surface condition result from using the air settling process compared to the green sand process. These include benefits in regards to surface inclusions, surface porosity, chips, and scabs. The i

details of a comparison between the required surface conditions and that which can be obtained by the air settling process are provided below.

i

During (casting, some of the components of the sand mixture are lost in the process of ojpIj ^ rja rgm &lt;

MEXICAN INSTITUTE

The wet sand can be reused after dfé^THEThe composition to replace lost moisture and the same pattern can be reused indefinitely to produce new sand molds. The sand molding process has been used for many centuries to produce hand cast parts. Since 1950, partially automated casting processes have been developed for production lines, including some hydraulic ones for compacting sand.

Green sand is an aggregate of sand (approximately 90%), bentonite clay or binder (approximately 7%), which includes pulverized charcoal, and water (approximately 3%). It is called green because like a green tree branch, it contains water. Most of the aggregate is always arfena, which can be silica or olivine. There are many recipes for the clay ratio, but they all provide different trade-offs between moldability, surface finish, and the ability of the molten metal to degas. Carbon, typically referred to in foundries as sea coal, is present in a proportion of less than 5% and partially in combustion in i

presence of molten metal leading to the release of organic vapor gases. In addition, the presence of water results in 2-3% in the occurrence of an increase in

<img file="MX339159B_D0010.tif" />

gas defects in, to pour after ι .. |_Μφ ^ cast steel. Gross discontinuities of the supeW ^ $ g * j¡ $ ev i

form as a result of gassing or vapors and can result in poor resistance to fatigue by couplers and coupling parts. Given the cyclical loading that coupler assemblies are subjected to, it is important to always provide as long a fatigue life as possible.

Another type of mold is a shell drying mold.

A shell drying mold starts out as a green sand mold, but additional bonding materials are i

are added and the cavity surface is dried using a heating torch or lamp to increase the strength of the mold. This improves dimensional accuracy and surface finish, but decreases collapsibility. Shell drying molds are more expensive and time consuming, thus reducing the production rate.

Another type of sand that can be used in sand casting is dry sand. In a dry sand mold, sometimes called a cold box mold, the sand is mixed with just!

an organic binder, ί The mold is strengthened by baking in an oven. The resulting mold has high dimensional accuracy, but is expensive and results in a higher production rate. low.

The casting process for the manufacture of couplers has historically used the sand process this process has served the railroad industry.^lwell7^: there are associated disadvantages; with the 3e green sand process, such as poor material strength, porosity and poor surface finish, resulting in shorter life

<img file="MX339159B_D0011.tif" />

of fatigue, great variation in; tolerance, and a secondary polishing / machining process is often required after the casting process.

In addition, a large number of weld repairs may be required in finishing time to fix surface or subfloor defects. Production rates are also low and include high finishing labor costs. For reasons that will become more apparent below, these disadvantages may require prior replacement of couplers and / or ball joints, and create additional manufacturing costs ^ that can be avoided. It would be beneficial, therefore, to use another casting process in the manufacture of rail couplings that exceed, or at i

Less attenuate, these drawbacks.

Brief Description of Figures

The system can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, rather the principles of the invention are emphasized. Furthermore, in the figures, like reference numerals designate corresponding parts in the different views.

i; Mexican institute Υχ *** ###? ** '

OF THE PROPERTY C ^ -—

Figure 1 is a perspective view of u ff ^D'to^Tó'ó-p I to the railroad manufactured by a no-bake process -; - o — ρτπ air settling.

Figure 2 is a perspective, disassembled perspective of a coupler assembly used to form the railroad coupler of Figure 1.

i

Figure 3 is a top perspective view of the body of the coupler of Figure 2.

Figure 4 is a side view, seen in cross section along line 4-4 of the coupler body of Figure 2.

Figures 5A and 5B are two perspective views of the body of the coupler of Figure 2, showing the location of the retaining shoulders of the coupler in relation to the pin hole of the coupler.

Figure 6 is a perspective view of the rail coupler of Figure 2, showing the location of the protective reinforcements of the pin in relation to the hole i

hitch pin.

Figure 7 is a side perspective view of the body of the coupler of Figure

Figure 8 is a cross-sectional view along line 8-8 of the copying body of Figure 7.

Figure 9 is a side perspective view of the body of the coupler of Figure 2

<img file="MX339159B_D0012.tif" />

INSTITUTO MEXICANO Pf la γκοπεραρ

INDUSTRIAL

<img file="MX339159B_D0013.tif" />

Figure 10 is a cross-sectional view along line 10-10 of the body of the coupler of Figure 9.

Figure 11 is a top view of the coupler ball joint of Figure 2.

Figure 12 is the cross-sectional view along line 12-12 of the ball joint of Figure 11.

Figures 1-3A and 13B are two perspective views of the ball joint of the rail coupler of Figure 11, showing the location of the ball joint's pull ears relative to the pin hole of the ball joint.

Figures 14A and 14B are two perspective views of the ball joint of the rail coupler of Figure 11, showing the location of the ball joint retaining shoulders in relation to the pin hole of the ball joint.

Figures 1-5A and 15B are two perspective views of the ball joint of the railroad coupler of Figure 11, showing the location of the ball joint pin protectors relative to the ball joint pin hole.

Figure 16 is a top view of the coupler ball joint of Figure 2, indicating the approximate dimension between the center of the ball pin hole and the ball joint polishing shoulder as approximately 3.5 inches (8.89 cm) and between the center of ball joint pin hole and ball joint pull lug to about 5.875 inches (14.92 cm).

Figure 17 is a bottom view of the LBYÁrütuJ; MEXICAN INSTITUTE

OF THE PROPERTY coupler from figure 2, indicating dimension a'fWB-iafa

<img file="MX339159B_D0014.tif" />

between the center of the ball joint pin hole and the chevroned edge of the ball joint about 3.5 inches (8.89 cm) and a half and between the center of the ball joint pin hole and the ball joint pull lug to 5.75 inches (14.61 cm). cm).

Detailed Description of the Invention

In some cases, well-known structures, materials, or operations are not shown or described in detail. Furthermore, the described features, structures or characteristics can be combined in any suitable way in one or more embodiments. It will also be readily understood that the components of the embodiments as generally described: and illustrated in the figures herein could be arranged and designed in a wide variety of different configurations.

Many of the drawbacks of using the green sand process mentioned above can be overcome, or at least improved, by using a no-bake casting process, or by air settling. No Bake and Air Set refers to the same type of process and is considered interchangeable throughout this description. The American Railroad Association (AAR) coupler 100, shown in Figure 1, is an assembly of parts, all of which are to interact in a precise manner for what

INDUSTRIAL coupler to function properly and for optimum life

<img file="MX339159B_D0015.tif" />

of the parts. Operating positions include locked, unlocked, and red-rimmed. Since coupling parts have been replaced during the life of a coupler, Parts Exchange must maintain proper Interface dimensions for proper operation. Therefore, the control of the dimensional characteristics of coupling parts is important for

I ensure proper operation.

i

The coupler also transmits longitudinal pulling and pushing forces to a rail car in service operations. These forces can be of a significant magnitude often many hundreds of thousands of kilograms - and require; that the load path of the force through the coupler assembly is precisely controlled. Design loads per AAR M211 specification come to 294.84 kg (65Q,000 lbs.) For the ball joint and 408.23 kg (900 lbs.) For the coupler body. The uniform load i

Helps to ensure uniform wear patterns and, in turn, the most uniform load distribution. Finally, the strength of the coupler and its resistance to fatigue is important in order to avoid premature failure of the parts, which is directly influenced by dimensional consistency and therefore the distribution level of larc ^ g ^^ i ^ ójn ^^&gt; '^

MEXICAN INSTITUTE

The finish of the surface or the cféfiN ^ opI texture has a definite effect on the maintenance of the fnor ^ oi

coupler required and fatigue strength. The no-bake casting process provides better dimensional control, improved load path for operating forces, more uniform wear patterns, castings with fewer weld repairs, and better surface texture for improved strength and resistance to corrosion. fatigue compared to the green sand process.

In no-bake moldé casting, the molten metal is poured into a non-reusable mold made from a mixture of ¡

sand, fast-setting resin, and catalyst, and the mold is held together until solidification occurs. The no-bake sand casting process produces a sand mold of considerable strength, which can stand alone without the need for a traditional steel jar, and therefore limited in size and shape. The traditional jar is sinful and rigid, limiting green sand operations due to molding efficiencies that result from the limitations of metal jars.

The no-bake casting process involves the use of chemically bonded sand systems. The use of chemical agglomeration agents typically makes the no-bake process somewhat more expensive than that!

<img file="MX339159B_D0016.tif" />

INSTITUTO MEXICANO arena verde. As part of the casting process If a resin and the catalyst are mixed together. Examples of gas catalysts used for curing include sodium silicate (CO2), amine, SO2, and phenolic systems cured with i

ester. Examples of a liquid catalyst may include the air settling system. Through a chemical reaction, the resin hardens and forms a very strong bond. Sometimes an accelerator can be added to speed up the hardening process. The no-bake casting process can also be less sensitive to air temperature and humidity compared to green sand operations.

The no-bake process uses oven-dried grain size sand, which is mechanically mixed with a resin (or binder) to bind the sand. Most binder systems are variations of a few basic chemicals, such as furan, phenolic urethane, and sodium silicate. The no-bake method of forming the mold is generally done at room temperature. Therefore, unlike the green sand process that requires curing the sand, water, and clay mixture at an elevated temperature, the no-bake process derives its name by eliminating the necessary baking process when using the bake method. green sand.

A chemical hardener is added entontje§¡ ^ [

INSTITUTO MEXICANA JA

OF Ι.Λ PROPERTY of sand, which reacts with the binder and eats^&lt;ñ^t2^Tto^iA1a rty-eFr— the sand in a solid form. At this point ·; · the liquid sand is poured into a mold around a standard or several standards. Once it is poured, the sand is allowed to dry. The binder causes the sand particles to bond together to form a very stable and precise shape for the cavity used to pour the final casting. Drying time depends on the type of hardener used. The sand settles on a solid block from which the skipper's equipment is taken.

The cores are then added to the mold and the mold is closed and ready for casting.

Refractory linings can be applied to resin bonded cores and molds. These liners are sometimes called as a wash. Coatings can be used for a number of reasons, including: (1) to improve surface finish, (2) to control heat transfer characteristics and microstructure in steel casting, (3) to improve core ventilation, and (4) to avoid a certain type? of defects in the casting.

In contrast to the green sand process, described, this hardened mold does not require the use of a flask of i

traditionally manufactured metal. Jar size limitations can be detrimental to the green sand process by preventing the manufacturer from varying the number of parts

<img file="MX339159B_D0017.tif" />

OF INDUSTRIAL PROPERTY

Multiple jars in a single jar or by limiting the piece jar that can fit into a jar of pre-existing metal jar sizes, pressed steel cannot be cost-effectively modified to accommodate new pieces of customer sizes. , if it is different from the jars used today. Buying multiple individual jars can be expensive. Typical sizes can be up to 1.22 m wide, 1.86 m long, and depths 46-60 cm (18-24 inches) deep for both the front and bottom. Consequently, an air-settled mold is well suited to larger and heavier castings as the force of the mold allows higher metal weights to be cast. A solid sand structure allows a mold of various sizes to be formed, producing the best available performances for each solid sand structure. Also, the use of sand for a mold can be kept to a minimum without compromising quality so that production costs are reduced. Chemical bonding | of the sand particles for the no-bake process provides for a better surface condition compared to the green sand process where water and clay are used as the bonding agents.

The current state of the art of casting equipment in the Icón aire settlement lines allows up to 100% recovery of the main raw material, sand. This reclaimed sand will decompose, cool down and be used repeatedly. To keep I^! wnurriuAL sand and the force of rnol ^ e, the recovered sand mixes

<img file="MX339159B_D0018.tif" />

include: molds that are q with new sand in a ratio of 75%: 25%. This process keeps production costs to a minimum without compromising quality. Note that the ratio of new sand to reclaimed sand varies depending on the typical casting geometry and weight, the ratio of 75%: 25% is just a typical value. Values ​​range from 95%: 5% to 40%: 60%.

Some of the features and advantages that distinguish the no-bake mold process from other sand molding processes, such as the green sand process, luimically cured at room temperature, the process produces accurate and reproducible dimensions, and the labor costs of finished and scrap are reduced, while high casting yields are obtained.

As a measure of the dimensional stability of the no-bake process compared to the green sand process, the "Steel Casters Society of the United States of America" ​​publishes the values ​​of the dimensional tolerances in Supplement 3 of the Casting Manual. Steel. Bas; e tolerances for castings made by the no-bake process are listed as plus or minus 0.05 cm (0.020 in.) Compared to plus or minus.

4 * minus 0.8 cm (0.030 inch) for the parts by the green sand process. While both^: sBfí'íiST ^^^ ió¹

INDUSTRIAL small, the ability to have tolerances down in the range of one third is important when it comes to ensuring proper load paths and operating characteristics of the coupling assemblies, as explained above. The tolerances of the mating parts depend on the weight and dimension of the casting as will be discussed later, so the tolerance reached with the no-bake process when compared to the green sand process varies across the different parts and rail coupling dimensions. In all cases, however, the tolerances achievable with the no-bake process are smaller than the tolerances required by the AAR M-211 specification.

i

The no-bake process also allows for smaller rake angles than the green sand process. A bank angle refers to the small slope included for the vertical surfaces of the casting pattern, oriented in the mold box, so that the pattern can be pulled out of the mold. The bank angle should be included in both the top and bottom of the!

patterns. When the green sand process requires a rake angle of 1.5 degrees or more for forms i

typical, the no-bake process requires only a 1.0 angle

<img file="MX339159B_D0019.tif" />

degrees for drag. When the (manual) process of sand ί I MP Ϊ green process requires a ^ angle of ¡ncl¡nac¡ ^, ^^ ¡Ag_TOi;

More INDUSTRIAL PROPERTY for deep bags, the no-bake process only requires a 1.5 degree projected angle of deep pockets. The required Tilt angle of the process of ¡

Green sand produces a significantly greater deviation from the nominal dimension at casting points that are further from the line on which the entire casting is pointing than a casting produced by the no-bake process.

ί

Smaller Tilt Angles can promote an i

better loading of parts and increase the support area. This small difference is significant when it represents the ί

interconnection of the complicated shapes that make up parts in a copier assembly, and when combined with a narrow tolerance range.

Figure 2 shows the main parts of a railroad coupler assembly 200, which includes a body 204, a ball joint 208, a pin ball joint 212, a launcher 216, a bolt 220, and a bolt lift 224. Of these main parts , ball joint 208 and body 204 are generally produced by the green sand casting process. Due to their small size, bolt 220, launcher 216, and bolt lifter assembly 224 can be produced by various methods. The launcher 216 can also be produced by the green casting sand process or by the forging process. The present description contemplates forming the body and the patella using the bake or air process for all the reasons previously discussed.

During locking and unlocking operations, ball joint 208 rotates about ball joint pin axis 212.

¡

The tail of ball joint 228 must pass under the seat of ball joint holder 232 in lock 220 during locking and unlocking operations. The lock must also move down and up in a locking chamber 236 of body 204 during locking and unlocking operations.

Also, during closing, the bolt 220 must move towards!

i up into the locking chamber 236 of the body in such a way

I that the bolt seat 240 in a bolt leg 244 precisely seats in a bolt leg seat 248 of the

Launcher216.

The parts of the coupler assembly 200 must have accurate dimensional characteristics to ensure successful operation. The better the dimensional characteristics, the smoother the operation. The greater the dimensional variation, the more difficult the operation will be, and if it is large enough, the parts will jam and the coupler may become unusable. The smooth surface finishes also helps in successful operation, which will be discussed in more detail below. If the part tolerances are

<img file="MX339159B_D0020.tif" />

FROM INDUSTRIAL PROPERTY too large, interference may drain £ uaa £ lo 4g¡ i 1 jL Jl i label 208 is rotated relative to the body'2

DÍLAP i INDUSTRIAL PROPERTY

220. This interference can lead to conditions that make locking and unlocking operations of the coupler difficult. In some cases, extreme tolerances in relative part dimensions have resulted in inoperability of the coupler and / or an inability to interchange parts.

The cargo path! of the coupler for drag (traction) and compression (thrust) forces generated during train operations also depends on an i

precise control of the dimensional tolerances of the coupling parts. For the tensile forces, the coupler i

it is designed to receive the pulling forces on the pull faces 252 of the rotators 208 (shown in Figures 14A, 14B) between two mating couplers. This traction force is transmitted through the ball joint 208 to the traction lugs 258 on the tail of the ball joints 228. At that point, the traction force is transmitted to the traction lugs 278 of the coupler body 204 as best seen. in figure 4. Finally, the split forces are transmitted through the body of the coupler 204 through a key slot i

279 or the cylinder head 280 of the coupler 204 to the traction system of the freight car and in the car body through the other end of the car. Yes! the tolerances of the coupling parts do not foresee the load path as described above, the: traction forces®hiTupll, J¿ ^

PE LA PROFIEPAP INDUSTRIAL transmitted through ball joint 208 to pin protectors 256 of the coupler body 204, to ball joint pin 212, and / or unevenly between the upper and lower part of the pull lugs 250, 278, which results in uneven and accelerated wear on these parts. In addition, the loads!

may be unevenly transmitted between corresponding coupler parts resulting in uneven loading. When the intended load path changes or there is load

I uneven between the upper and lower pull lugs 278, premature failure or reduced life of the part in the body of the coupler i 204, the ball joint pin 212, and / or the ball joint 208 can occur.

Compressive forces are greatest during switching operations when freight cars impact each other. The coupler assembly is designed to react to compressive forces on the shoulders of i

i containment 260 of the body of the coupler 204 and on the shoulders

I containment 261 of the ball joint 208. If the tolerances of the coupling parts are not precisely controlled, the compression forces can be transmitted in the pin protectors 256 :, 286 (see figures 6, 15A, 15B), the ball joint pin 212, or unevenly between the upper and lower containment shoulders 260, 261 of the body 204 and the ball joint 208, respectivelyJ Therefore it can

<img file="MX339159B_D0021.tif" />

and result in the premature failure of the ^ norbii ' ^J OELAPRf FtfOAP

IbKAlíTMAL ball joint pin 212, and / or coupler body 204. Therefore, it is advantageous to minimize dimensional tolerances so that proper load paths are maintained throughout the coupler assembly. These proper load paths promote uniform wear patterns.

While the process used successfully during green sand casting has been for many years to produce mating parts, the no-bake casting process results in a better surface finish and therefore can reduce cracking and associated problems. that are created when surface conditions are not optimal. The higher costs normally associated with the no-bake process have been minimized or offset by: the reduction i

of casting finishing time (sizing), lower capital expenditure on items such as specialty jars that are not needed, requiring less weld repair of casting defects, reducing processing time, and that produce dimensionally more consistent and higher quality parts with longer part life.

The creation of a good surface finish or texture has been established as a priority by the American Association of Railroads (AAR) through measures adopted,

<img file="MX339159B_D0022.tif" />

DE LA PE,&gt; W £ DaD INDUSTRIAL

Car collection and casting systems committee. In the above conditions, certain surfaces, such as sand inclusions and seams, have been found in the critical areas of mating parts. In some cases, surface conditions can produce cracks that result in reduced fatigue life of the coupler or ball joint. For example, a radius area 281 between the coupler horn 264 and the stem; 268 has received the attention of the Federal Railroad Administration. See Code of Federal Regulations, Title 49, 215,123. Cracks in this area now require replacement of the coupler. Additionally, a smoother surface achieved through use of the no-bake process promotes the tightest tolerances, which are discussed below. A part manufactured to closer tolerances has a better fit and works better with its mating parts, which also increases fatigue resistance.

In the effort to ensure that surface conditions do not result in premature coupler failure, the Car Casting and Coupling Systems Committee has included specific surface finish criteria as part of the AAR M-211 specification. Casting and product approval requirements for the manufacture of couplers, coupler yokes, tags, follower blocks, and

<img file="MX339159B_D0023.tif" />

last time parts

AAR M-211 surface,

Definition

Coupling steel, specification M-211 i INSTITUTO MEXICANO in October 2009. Section 11.2 of the ai outlines the specific levels of_aq^ffp^{tani &lt;Sn lo}that are defined using the Checks for Surface Quality of Cast Pieces of the Research and Trade Association of

Steel Castings (SCRATA). SCRATA comparators have nine categories, each with five quality levels, going from 1 to 5, in which level 1 is the highest quality and level 5 is the lowest:

A. surface roughness - the natural surface of the part after blastingL

B. Surface inclusions - non-metallic material trapped in the casting surface.

C. Gas porosity - indications of gas on the surface of the casting.

D. Chips and cold joints - Irregularities in the surface giving a wrinkled appearance.

E. Scabs - Slightly raised surface irregularities. ;

F. Garlands - the; indications of garlands or internal hardening.

G. Surface Finish - Thermal Coating - the surface that remains after using oxygen gas or carbon air for elimination of arcing processes in metal.

<img file="MX339159B_D0024.tif" />

H. Surface finish - Coating

INDUSTRIAL surface that remains after using a mechanical means partially removed by to coat a cast surface or a surface previously thermally coated.

J. Welding - indications of welds, total or thermal or mechanical coating.

The following Tables 1 and 2 are comparison charts respectively for Coupling 204 and Clavicle 208 showing the minimum surface conditions required by the AAR M-211 specification and the improved surface conditions that can be achieved using the no-bake process. Figure A. eleven Referenced in Table 1 is a three-page figure shown in Appendix A of the M211 specification where the shaded areas are the critical areas and the unshaded areas are the non-critical areas. A person skilled in the art of rail couplings will know how to refer to Figure A.11 to determine which areas are currently considered critical as opposed to non-critical areas.

criticism by the AAR. In general, however, the critical areas ¡

These are those areas that receive more load force with respect to the drag and compression forces discussed above and also those areas that interact or wear out with other parts.

<td colspan="4">Tff Tk £ T</td><td></td>

<td>Category</td><td>Critical area (figure A.11 j</td><td>With not baked"</td><td>Area (figure Α. · Η $ ™</td><td></td>

<td rowspan="2">A) Roughness of the surface</td><td rowspan="2">A3</td><td rowspan="2">A1</td><td>A3</td><td>A1</td>

<td></td><td></td>

<td>B) Inclusions of surface</td><td>B2 i</td><td>B2</td><td>B4</td><td>B3</td>

<td>C) Porosity of gas</td><td>C2</td><td>C2</td><td>C3</td><td>C2</td>

<td>D) Chips</td><td>D1</td><td>D1</td><td>D4</td><td>D1</td>

<td>E) Scabs</td><td>E2</td><td>E1</td><td>E2</td><td>E1</td>

<td>F) Garland</td><td>F2</td><td>F1</td><td>F4</td><td>F1</td>

<td>G) Coating thermal</td><td>G2&gt;</td><td>G1</td><td>G3</td><td>G1</td>

<td>^H&gt;. Coating mechanical</td><td>H3</td><td>H1</td><td>H4</td><td>H1</td>

<td>J) Welds</td><td>J2</td><td>J1</td><td>J3</td><td>J1</td>

casting process, but re

Table 1: Coupling body

The data in Table 1 were obtained through visual comparison of a number of coupling bodies 204 produced by the no-bake process with SCRATA pilacas representing 1 to 5 in each of the above categories. With reference to categories D to J in table 1, no chips, crusts, were observed.

garlands or welds. Also, the surface conditions of the thermal coating and mechanical coating are not dependent on the result of individual performance surface conditioning after the casting process has been completed. The frequency with which thermal and mechanical coating operations must be carried out is, however, a result of the casting process, therefore it follows the ¡· INSTITUTO MEXICANO &lt;$} comparison with the green sand process. How I know^Mm $ w ^ L | gS £ «? 2 ^ surface quality of a produced-pair coupling. the · no-bake process is superior by; all categories, and at least equal to the minimum requirements under the M.211 specification of

AAR.

<td>Category</td><td>Critical area (figure A. 11)</td><td>to</td><td>With not baked"</td><td>Non-critical area (figure A. 11)</td><td>With not baked"</td>

<td>A) Roughness of the surface</td><td>A3</td><td></td><td>A1</td><td>A3</td><td>A1</td>

<td>B) Inclusions of surface</td><td>B2</td><td></td><td>B2</td><td>B4</td><td>B3</td>

<td>C) Porosity of gas</td><td>C2</td><td></td><td>C2</td><td>C3</td><td>C2</td>

<td>D) Chips</td><td>D1</td><td></td><td>D1</td><td>D4</td><td>D1</td>

<td>E) Scabs</td><td>E2</td><td></td><td>E1</td><td>E2</td><td>E1</td>

<td>F) Garland</td><td>F2</td><td></td><td>F1</td><td>F4</td><td>F1</td>

<td>G) Coating thermal</td><td>G2</td><td></td><td>G1</td><td>G3</td><td>G1</td>

<td>H) Coating mechanical</td><td>H3</td><td></td><td>H1</td><td>H4</td><td>H1</td>

<td>J) Welds</td><td>J2</td><td></td><td>J1</td><td>J3</td><td>J1</td>

Table 2: Patella

The data in table 2 were obtained through visual comparison of a number of hinges produced by the non-baking process with SCRATA plates representing 1 to 5 in each of the previous categories. With reference to categories D to J in table 1, no crusts, garlands or welding were observed. As with the coupling, the surface quality of the ball joints was superior to all categories, or at least equal to the minimum requirements under AAR specification M-211.

I

The no-bake process can be used to manufacture the coupling body 204, the tag 208, the!

bolt 220, launcher 216, i and bolt lifter 224 such that better (smaller) tolerances are achieved for various relative dimensions due to the no-bake process. As discussed above, the tolerances for the no-bake process are plus minus 0.05 centimeters (0.020 inches) and the drag angle is around one (1.0) degrees or less for typical characteristics. Current tolerances, however, vary with the weight and dimension of the i

Cast parts according to the tolerance tables of the Steel Founders Society (SFSA). Table 3 below shows the T3 tolerances used for the no-bake process used by manufacturers. In comparison, Table 4 shows the T5 tolerances that correspond to the green sand process typical of conventional rail couplings.

Tolerances (+. Centimeters) for the casting weight grade in kilograms.

<img file="MX339159B_D0025.tif" />

OF INDUSTRIAL PROPERTY

<img file="MX339159B_D0026.tif" />

<td>L</td><td> 0.908</td><td>^Γ 2270</td><td> 4.540 '</td><td> 9.080</td><td> 22700</td><td>^r 34.050</td><td> 45.400 ^r</td><td> 68.100</td><td> 90.800 '</td><td> 113.500</td><td> 227.000 '</td><td> 340.500</td><td> 454.000 '</td><td> 567.500</td><td> 681.000 ^r</td><td> 908.000</td><td> 1,362.000 '</td><td> 1,816.000</td>

<td>L27</td><td> 0.061</td><td> 0.066</td><td> 0.071</td><td> 0.079</td><td> 0.091</td><td> 0.099</td><td> 0.104</td><td>0.1Í2</td><td> 0.119</td><td> 0.124</td><td> 0.145</td><td> 0160</td><td> 0.173</td><td> 0.180</td><td> 0.191</td><td> 0.206</td><td> 0.229</td><td> 0.246</td>

<td> 2.54</td><td> 0.071</td><td> 0.079</td><td> 0.084</td><td> 0.091</td><td> 0,104</td><td> 0.109</td><td> 0.114</td><td>0.1Í4</td><td> 0.130</td><td> 0137</td><td> 0157</td><td> 0173</td><td> 0.183</td><td> 0.193</td><td> 0.201</td><td> 0.216</td><td> 0.239</td><td> 0.257</td>

<td> 5.08</td><td> 0.086</td><td> 0.091</td><td> 0.099</td><td> 0.104</td><td> 0.117</td><td> 0.124</td><td> 0.130</td><td> 0137</td><td> 0.145</td><td> 0150</td><td> 0173</td><td> 0185</td><td> 0.198</td><td> 0.208</td><td> 0.216</td><td> 0.231</td><td> 0.254</td><td>0.Z72</td>

<td> 10.16</td><td> 0.104</td><td> 0.112</td><td> 0.117</td><td> 0.124</td><td> 0.137</td><td> 0.142</td><td> 0.147</td><td> 0.157</td><td> 0.163</td><td> 0170</td><td> 0.191</td><td> 0.206</td><td> 0.216</td><td> 0.226</td><td> 0.234</td><td> 0.249</td><td> 0.272</td><td> 0.290</td>

<td> 15.24</td><td> 0.117</td><td> 0.124</td><td> 0.130</td><td> 0.137</td><td> 0.150</td><td> 0.155</td><td> 0.160</td><td> 0.170</td><td> 0.175</td><td> 0183</td><td> 0,203</td><td> 0218</td><td> 0.229</td><td> 0.239</td><td> 0.246</td><td> 0.262</td><td> 0.284</td><td> 0.305</td>

<td> 20.32</td><td> 0.127</td><td> 0.135</td><td> 0.142</td><td> 0.173</td><td> 0.160</td><td> 0.165</td><td> 0.170</td><td> 0.180</td><td> 0.185</td><td> 0193</td><td> 2134</td><td> 0.229</td><td> 0.239</td><td> 0.249</td><td> 0.257</td><td> 0.272</td><td> 0.295</td><td> 0.315</td>

<td> 25.40</td><td> 0.137</td><td> 0.142</td><td> 0.147</td><td> 0.155</td><td> 0.168</td><td> 0.175</td><td> 0.180</td><td> 0.188</td><td> 0.196</td><td> 0.201</td><td> 0.221</td><td> 0.236</td><td> 0.249</td><td> 0.257</td><td> 0.267</td><td> 0.282</td><td> 0.305</td><td> 0.323</td>

<td> 38.10</td><td> 0.155</td><td> 0.160</td><td> 0.165</td><td> 0.173</td><td> 0.185</td><td> 0.193</td><td> 0.198</td><td> 0.206</td><td> 0.213</td><td> 0218</td><td> 0.239</td><td> 0254</td><td> 0.267</td><td> 0.274</td><td> 0.284</td><td> 0.297</td><td> 0.323</td><td> 0.340</td>

<td> 50.80</td><td> 0.168</td><td> 0.175</td><td> 0.180</td><td> 0.188</td><td> 0.198</td><td> 0.206</td><td> 0.211</td><td> 0.221</td><td> 0226</td><td> 0231</td><td> 0.254</td><td> 0.267</td><td> 0.279</td><td> 0.290</td><td> 0.297</td><td> 0.312</td><td> 0.335</td><td> 0.353</td>

<td> 76.20</td><td> 0.191</td><td> 0.196</td><td> 0.201</td><td> 0.208</td><td> 0.221</td><td> 0.229</td><td> 0.234</td><td> 0.244</td><td> 0.249</td><td> 0.254</td><td> 0.274</td><td> 0.290</td><td> 0.302</td><td> 0.312</td><td> 0.320</td><td> 0.335</td><td> 0.358</td><td> 0376</td>

<td> 101.60</td><td> 0.208</td><td> 0.213</td><td> 0.218</td><td> 0.226</td><td> 0.239</td><td> 0.246</td><td> 0.251</td><td> 0.259</td><td> 0.269</td><td> 0272</td><td> 0.292</td><td> 0.307</td><td> 0.320</td><td> 0.328</td><td> 0.338</td><td> 0.353</td><td> 0376</td><td> 0.394</td>

<td> 127.00</td><td> 0.224</td><td> 0.229</td><td> 0.234</td><td> 0.241</td><td> 0.254</td><td> 0.262</td><td> 0.267</td><td> 0.274</td><td> 0.282</td><td> 0287</td><td> 0307</td><td> 0.323</td><td> 0.333</td><td> 0.345</td><td> 0.353</td><td> 0.366</td><td> 0.391</td><td> 0.409</td>

<td> 152.40</td><td> 0.236</td><td> 0.241</td><td> 0.246</td><td> 0.254</td><td> 0.267</td><td> 0.274</td><td> 0.254</td><td> 0.287</td><td> 0.295</td><td> 0300</td><td> 0320</td><td> 0.335</td><td> 0.348</td><td> 0.356</td><td> 0.366</td><td> 0.381</td><td> 0.429</td><td> 0422</td>

* length dimension in centimeters

Table 3: Non-baking tolerances Tolerances (+ centimeters) for tolerance grade T5 casting weight in kilograms.

<td></td><td> 0.908</td><td> 2.270</td><td> 4.540</td><td> 9.080</td><td> 22.700</td><td> 34.050</td><td> 45.400</td><td> 18.100</td><td> 90.800</td><td> 113.500</td><td> 227.100</td><td> 340.500</td><td> 454.010</td><td> 567.500</td><td> 681.000</td><td colspan="4"> 908000 1,362.000 1,816.000 2270.000</td>

<td> 152</td><td> 0097</td><td> 0.114</td><td> 0132</td><td> 0.155</td><td> 0.193</td><td> 0.216</td><td> 0.234</td><td> 0262</td><td> 0282</td><td> 0.300</td><td> 0368</td><td> 0414</td><td> 0.452</td><td> 0483</td><td> 0511</td><td> 0556</td><td> 0.630</td><td></td><td></td>

<td> 2.54</td><td> 0107</td><td> 0.124</td><td> 0.170</td><td> 0.168</td><td> 0205</td><td> 0229</td><td> 0244</td><td> 0272</td><td> 0295</td><td> 0312</td><td> 0.378</td><td> 0.424</td><td> 0412</td><td> 0493</td><td> 052,</td><td> ¢.559</td><td> 0.643</td><td> 070,</td><td> 0752</td>

<td> 5.08</td><td> 0122</td><td> 0.142</td><td> 0157</td><td> 0,80</td><td> 0221</td><td> 0241</td><td> 0259</td><td> 0287</td><td> 0.307</td><td> 0.328</td><td> 0.394</td><td> 0439</td><td> 0478</td><td> 0.508</td><td> 0.536</td><td> 0.582</td><td> 0.658</td><td> 0.716</td><td> 0.715</td>

<td> 1016</td><td> 0165</td><td> 0.157</td><td> 0.178</td><td> 0201</td><td> 0239</td><td> 0262</td><td> 0277</td><td> 0.305</td><td> 0328</td><td> 0345</td><td> 0411</td><td> 0.457</td><td> 0.495</td><td> 0526</td><td> 0.554</td><td> 0602</td><td> 0675</td><td> 0734</td><td> 0.705</td>

<td> 15,24</td><td> 0152</td><td> 0,73</td><td> 0.191</td><td> 6.213</td><td> 0.261</td><td> 0274</td><td> 0.290</td><td> 0318</td><td> 0340</td><td> 0858</td><td> 0424</td><td> 0.472</td><td> 0508</td><td> 0.541</td><td> 0516</td><td> 0.615</td><td> 0688</td><td> 0747</td><td> 0.798</td>

<td> 20.32</td><td> 0163</td><td> 0,83</td><td> 020,</td><td>ra</td><td> 0262</td><td> 0284</td><td>W</td><td> 0328</td><td> 035,</td><td> 0868</td><td> 0434</td><td>"M"</td><td> 0.5,8</td><td> 0.55,'</td><td> 0577</td><td>^—now</td><td> 0699</td><td> 0.757</td><td>it"</td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> 25,40</td><td> 0173</td><td> 0191</td><td> 0.208</td><td> 1231</td><td> 0272.</td><td> 0295</td><td>Ó.3ÍÓ</td><td> 0.338</td><td>&lt;L3Sl</td><td> 0376</td><td> 0445</td><td> 0490</td><td> 0528</td><td> 0559</td><td> 0.587</td><td> 0.632</td><td> 0.706</td><td> 0767</td><td> 0.815</td>

<td> 40.64</td><td> 0193</td><td> 0.299</td><td> 0226</td><td> 0249</td><td> 0.287</td><td> 0.310</td><td> 0328</td><td> 0356</td><td> 0.376</td><td> 0419</td><td> 0.(60</td><td> 0.508</td><td> 0.546</td><td> 0.577</td><td> 0.605</td><td> 0.676</td><td> 0726</td><td> 0782.</td><td> 0.833</td>

<td>SÜT</td><td> 0203</td><td>Ί22Γ</td><td> 0.229</td><td>126Y</td><td> 0302</td><td> 0.323</td><td> 0340</td><td> 0.368</td><td> 0.391</td><td> ' 0409</td><td> 0.475</td><td>or if'</td><td> 0559</td><td> 0580'</td><td> 0.617</td><td> 0665'</td><td>o.ü '</td><td> 0.798</td><td>"Ó848</td>

<td> 7620</td><td> 0225</td><td> 0.2(4</td><td> 0262</td><td> 1.284</td><td> 0325</td><td> 0.3(5</td><td> 0.363</td><td> 0391</td><td> 0.411</td><td> 0,429</td><td> 0.498</td><td> 0544</td><td> 0.582</td><td> 0.6,2</td><td> 0.640</td><td> 0.686</td><td> 0759</td><td> 0.820</td><td> 0.859</td>

<td> 101.60</td><td> 0.244</td><td> 0.25!</td><td> 0279</td><td> 1.302</td><td> 0.345</td><td> 0363</td><td> 0406</td><td> 0409</td><td> 0.429</td><td> 0.434</td><td> 0516</td><td> 0561</td><td> 0.599</td><td> 0.630</td><td> 0683</td><td> 0704</td><td> 0777</td><td> 0.838</td><td> 0064</td>

<td> 127.00</td><td> 0.259</td><td> 0277</td><td> 0295</td><td> 1.318</td><td> 0.356</td><td> 0.378</td><td> 0396</td><td> 042</td><td> 0.445</td><td> 0462</td><td> 0528</td><td> 0577</td><td> 0.612</td><td> 0671</td><td> 0673</td><td> 0719</td><td> 0.792</td><td> 0851</td><td> 0930</td>

<td> 152.40</td><td> 0.272</td><td> 0.290</td><td> 0.307</td><td> 1.330</td><td> 0371</td><td> 0391</td><td> 0.409</td><td> 0.437</td><td> 0.457</td><td> 0475</td><td> 0.544</td><td> 0.589</td><td> 0627</td><td> 0.683</td><td> 0.186</td><td> 0732</td><td> 0.805</td><td> 0866</td><td> 09,4</td>

'length dimension ^ in centimeters

Table 4: green sand tolerances

ΟΒβΜλ:

As an example, suppose that a part j [] ^ / ¡aJ ¹ MEXICAN INSTITUTE,. . . FROM PROPERTY made with both no-bake and sandblasting processes^stwatch

<img file="MX339159B_D0027.tif" />

both weigh about 45.4 kilograms · (1QO — 14-b-ra-s) ·. · Suppose a dimension of interest is 5.08 centimeters (2.0 inches). The achievable tolerance in the no-bake process is around 0.13 centimeters (0.051 inches while the tolerance for the part made by the green sand process is around 0.26 centimeters, which is about twice what can be achieved. with the no-bake process.

Figure 3 is a top perspective view of the coupling body 204 of Figure 2. Figure 4 illustrates a side cross-sectional view along line 4-4 of the coupling body 204 of Figure 2, including holes for coupling bolt 272 through which the ball joint pin 212 is inserted, and pull tabs 278 of the coupling body 204 which correspond to the pull lugs 258 of the ball joint 208. The balanced load that is achieved through the baking process results in even more wear on the coupling body pull lugs 278, thus extending the coupling body fatigue. The tolerances that can be achieved, discussed below, using the no-bake process for dimensions define the position of the body pull lugs 278 relative to the coupling bolt holes.

272.

......

<img file="MX339159B_D0028.tif" />

. r- - ... OF THE PROPERTY

Figures 5A and 5B are two views in, perspe * 2TfW^L di coupling body 2Q4 of figure 27 - mootrondo the position of the containment shoulders 260 in relation to the coupling bolt hole 272 that can be achieved with the no-bake process. FIG. 6 is a perspective view of the rail coupling of FIG. 2, showing the position of the pin guard patterns 256 relative to the coupling pin hole 272 that can be achieved with the no-bake process.

Figure 7 is a side perspective view of the coupling body 204 of Figure 2. Figure 8 is a cross-sectional view along line 8-8 of the coupling body of Figure 7. Figure 9 is a side perspective view of the coupling body 204 of Figure 2. The i

Figure 10 is a cross-sectional view along line 10-10 of the slow coupling body 204 of line 8-8 shown i

in Figure 8. The 3.5-inch dimension in both Figures 8 and 10 is the approximate distance between the center of the coupling pin holes 272 and the retaining shoulders!

260 relative to the coupling pin hole 272 that can be achieved with the no-bake process. Based on the approximate weight of 171.46 kilograms (378 pounds), the tolerance for this dimension is approximately plus minus 0.19 i

centimeters (0.075 inches) using table 3. The tolerance '- *¹* resulting from the green sand process resu of plus minus 0.41 centimeters using the INDUSTRIAL table with this, the tolerance achievable with the process of no

<img file="MX339159B_D0029.tif" />

Baking is less than half that which can be achieved using the green sand process.

Since the weight must be rounded to 226.80 kilograms (500 pounds) and the length to 10.16 centimeters (4 inches) in the example in figure 8 to use the AAR tables, the quoted tolerances are only estimates and probably even greater than reality. in this case. For example, the 8.89 centimeter (3.5 inch) dimension results in a tolerance closest to plus minus 0.070 inch. Also, due to the pull angles discussed above, and due to inclined surfaces designed with some features, the dimension changes somewhat along the measured features. Accordingly, the dimensions themselves vary to a certain degree and showing a specific length, or mentioning a specific tolerance, should not be considered as exact values ​​but close approximations. Therefore, the difference between approximate tolerances between the no-bake processes and the green sand more adequately describes the improvement of the use of the no-bake process in terms of dimensional tolerances.

Figures 8 and 10! also show additional dimensions: 3.81 centimeters between the center of the holes of i

coupling pin 272 and pin patterns 256 and 14.61 centimeters (5.75 inches) &lt;

r »ι ·, ι ·· ι ^» ϋ · ΐώ ii. ·, ·, .- '«. · yjh · ..

<img file="MX339159B_D0030.tif" />

of the coupling pin holes 272 and the pull lugs 278 of the coupling body 204. Using the same estimate of 226.80 kilograms, and rounding to 5.08 centimeters, the 3.81 centimeters (inches) dimension in Table 3 indicates a tolerance of about plus minus 0.17

I

I inches, although it's actually probably less, like plus minus 0.062 inches from the scratches discussed above. The corresponding tolerance from Table 4, using the green sand process, is approximately plus minus 0.155 inches, which is more than double what can be achieved with the no-bake process.

I

Using the same estimate of 550 pounds, and rounding to 6 inches, the dimension of; 5.75 inches in Table 3 indicates a tolerance of about plus or minus 0.080 inches. Due to rounding, this tolerance is probably closer to plus minus 0.075 inches. The corresponding tolerance from Table 4 using the green sand process is about plus minus 0.167 inches, again about double what can be achieved with the no-bake process.

Figure 11 is a top view of the ball joint.

coupling of Figure 2.I Figure 12 is a cross-sectional view along the (line 12-12 of the ball joint of Figure

eleven. Figures 11 and 12 show the hole __ patella 282 in relation to the shoulders of conten'CT ^ XH ^ Xfttr ^^ * '**

INDUSTRIAL

261 and to the ball joint traction ears 258.

Figures 1-3A and 13B are two perspective views of the ball joint of the rail coupling of Figure 11, showing the position of the ball joint pull lugs 258 relative to the ball joint pin hole! 282 as formed by the no-bake process. Figures 14A and 14B are two views in i

Perspective of the ball joint of the rail coupling of FIG. 11, showing the position of the ball containing shoulders 261 relative to the pin hole of the ball joint 282 as formed by the no-bake process. Figures 1-5A and 15B are two perspective views of the ball joint of the rail coupling of Figure 11, showing the position of the ball joint pin guard patterns 286 relative to the ball joint hole 282 as formed by the process. not baked.

Figure 16 is one! top view of the coupling ball joint of Figure 2, indicating the approximate dimension between the center of ball pin hole 282 and ball joint restraining shoulder 261 as being about 8.89 centimeters; between the center of the ball pin hole 282 and the ball joint pull ear 258 about 5.875 inches; and between the center of the pin hole 282 and the pin guard patterns 286 as about 4.13 centimeters. With approximate weight urj_γ4 about 39.01 kilograms, the dimension of i8sT &amp; nt ^_R^^^

INDUSTRIAL tolerance of about plus minus 0.14 inches using the no-bake process compared to about plus minus 0.103 inches for the green sand process. (In this case, rounding causes the: tolerances quoted as less than reality, but still close approximations.) Relative tolerances again indicate a two-fold improvement in tolerance when using the no-bake process.

The 14.02 centimeter dimension between the ball joint pull lug 258 and the ball joint pin hole 282 results in a tolerance of about 0.15 centimeter for the no-bake process and in comparison to about plus minus 0.27 cm for the baking process. green sand, which is not a double improvement. The 1.625 dimension between the ball pin hole 282 and the pin guard patterns 286 results in a tolerance of about plus or minus 0.12 centimeters for the no-bake process compared to about plus or minus 0.24 centimeters for the green sand process, again one ¡

double improvement.

Figure 17 is a bottom view of the coupling ball joint of Figure 2, indicating the approximate dimension between the center of the ball pin hole 282 and the ball joint restraining shoulder 261 as about 8.89

<img file="MX339159B_D0031.tif" />

centimeters; between the center of the hole

MEXICAN INSTITUTE

282 and the ball joint pull ear 258 as of 5.T &amp; iwrfgia and between the ball joint pin hole 282 and the pin protection patterns 286 give about 4.13 centimeters. The only dimension that differs from those shown in the figure is the dimension between the ball joint pin hole 282 and the ball joint pull ear 258, which still results in an i

tolerance of plus or minus 0.15 centimeter for the no-bake process compared to around plus or minus 0.108 for the green sand process, almost a double improvement. The terms and descriptions used herein are presented as Illustration and are not intended to be limiting. Those skilled in the art will recognize that several variations can be made ai

the details of the modalities described above without departing from the basic principles of the modalities described.

!

For example, method steps do not need to be executed in a certain order, unless specified, although they may have been presented in that order in the description. The spectrum of the Invention should therefore be determined only by the following claims (and their equivalents) wherein all terms are to be understood in their broadest reasonable sense unless otherwise indicated.