Abstract:
A liner for use in a draft sill to protect the sill from damage and wear caused by draft gear movement. The draft gear is attached to a coupling to transmit moving forces from the coupling to the car causing. The draft gear is isolated from the side walls of the draft sill by the liner to reduce wear on the draft sill as the draft gear absorbs and cushions impacts from the buff and drag events. These impacts may cause the followers, yoke and resilient members move toward the side walls and contact the liner disposed between the draft gear and the draft sill for protecting the side walls from damage and wear.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to railcar coupling systems, and more particularly to rail car connection assemblies comprising draft gears and draft sills and couplers in railcars. 
         [0002]    Rail cars are interconnected by couplers attached to draft gear assemblies at the ends of adjoining railroad freight cars. The draft gear assembly is disposed in the draft sills at the ends of the freight cars. The draft sills are commonly cast or fabricated sills that are mounted at the ends of the center sills of the railcar. The sidewalls of the draft sill each have a front stop and a rear stop, with a draft gear pocket between the stops. The draft gear assembly is received in the draft gear pocket. The draft rear is connected to the coupler and adapted to transfer motion to the car while absorbing impacts from train action events. A front resilient member cushions the coupling from impacts caused by draft events where the coupling is pulled away from the car. A rear resilient member is built into the draft gear to protect the coupling from buff events where the coupling is forced toward the car. This movement of the coupling causes an expansion and compression of the resilient members and movement of the yoke and followers of the draft gear. 
         [0003]    The components of the draft gear may deflect from the axis of the draft sill causing the yoke, followers or resilient members to come in contact with the draft sill sidewalls inside the draft gear pocket. This contact can be very severe causing damage to the draft sill. The damage increases the maintenance and reduces the service time for the car. Draft sills are adapted to allow replacement of the draft gear and coupling but, draft sill repair requires more time and labor. 
       DESCRIPTION OF THE RELATED ART 
       [0004]    Rail car coupling systems such as the Rail Car Gear Assembly and System disclosed and claimed in U.S. Pat. No. 6,446,820 and the Common Cast Draft Sill for Type E and F Draft Gear disclosed and claimed in U.S. Pat. No. 6,986,432 are commonly owned by the assignee of the present invention Amsted Industries, Inc., are hereby incorporated in their entirety. These systems comprise a steel draft sill having the draft gear mounted therein. 
         [0005]    In the &#39;820 patent for the Rail Car Gear Assembly and system discloses and claims an improved dampening system for use in absorbing shock caused by the impact of cars in a start or stop condition or during a changing load. Each draft gear assembly is connected to one coupler, and couplers of adjacent rail cars are connected to form the train. The train may be hundreds of cars long and drawn by one or more locomotives. Typically, there is a limited amount of slack or free movement allowed between the cars; generally there is about two (2) inches of slack. This slack permits the rail cars limited movement toward and away from each other in response to train action and yard impact events. The integrity of the draft sill is important for safety reduced operating cost and performance. Excess wear on the inside of the sidewalls of the draft sills causes premature failure or increased maintenance. 
         [0006]    The &#39;432 patent discloses and claims a draft sill having a common design for use with E and F type draft gear. The &#39;432 patent has common design features to reduce the components needed to maintain rail cars. The &#39;432 patent discloses and claims a draft sill for use with more than one design of draft gear. 
         [0007]    Train action events include, for example: locomotive start up and acceleration, moving up and down inclined terrain, dynamic braking, differences in braking forces of adjacent cars, and gravity-induced movement of the cars as the train moves onto and away from inclines. Yard impact events include “humping” of the individual cars to build the train in the yard; in humping, a car is pushed over a hump in the track in the yard, released and allowed to roll down the incline of the hump toward an awaiting car; during humping, the released cars can reach speeds of 4-10 mph and can severely impact the coupler of the awaiting car. 
         [0008]    Train action and yard impact events both subject the couplers of the cars to buff impacts, and train action events also subject the couplers to draft impacts. These impacts are transmitted from the couplers to the draft gear assemblies to the rail car body. That is, as the couplers are pulled or pushed, the movement is translated to the freight car body through the draft gear assemblies. Typical draft gear assemblies include a yoke element that is connected to the coupler through a pin or key, a coupler follower and a draft gear, as well as other elements. Generally, the coupler follower is positioned against or closely spaced from the butt end of the coupler in the draft gear pocket, within the yoke. The draft gear is positioned between the coupler follower and the rear stops of the draft sill; other elements, such as a wedge, may be interposed between the draft gear and the coupler follower. 
         [0009]    In buff events, the butt end of the coupler moves inward against the coupler follower toward the rear stops of the draft sill. As the coupler and coupler follower are moved rearward, the shock of the movement is transferred to the draft gear. The draft gear typically absorbs and dissipates some of the energy from this shock through friction. Friction within the draft gear is acceptable as a means for absorbing the impact because the draft gear is replaceable. Friction between the draft gear and the draft sill is not acceptable as it causes damage to the draft sill that is harder and more expensive to repair or replace. 
         [0010]    In draft events, slack is taken up between adjacent cars beginning at one end of the train and ending at the other end of the train. As a result of the slack being progressively taken up, the speed differences between the railcars increases as the slack at each coupler pair is taken up, with a resultant increase in buff and draft impacts on the couplers. For instance, during locomotive acceleration of a 50-car train from rest there is a total of 100 inches of slack between the 50 pairs of couplers in the train. This slack is taken up progressively, coupler pair by coupler pair. When the 2 inch slack in the coupler pair joining the last car to the train is taken up the next to the last car may be moving at a speed of 4 miles per hour. The slack in the last coupler pair is taken up very rapidly and the last two cars are subjected to a very large impact capable of injuring the lading or the car. The impact causes the resilient members of the draft gear to expand or compress creating a possible frictional engagement between parts of the draft gear and the sidewalls of the draft sill causing damage. 
         [0011]    Various types of draft sill have been proposed and used. In U.S. Pat. No. 5,931,101 issued on Aug. 3, 1999 to Kaufhold et al. for an invention a LIGHT WEIGHT DRAFT SILL is commonly owned by Amsted Industries, Inc., the assignee for the present application for patent. The &#39;101 patent discloses and claims a draft sill that is lighter weight by removing material in specific locations on the draft sill. The draft sill may still be susceptible to failure due to wear between the draft gear and the draft gear because of less steel used to reduce weight. Accordingly there is a need for an invention to protect the draft sill from damage by the movement of the draft gear. The patent U.S. Pat. No. 5,931,101 for a LIGHT WEIGHT DRAFT SILL is hereby incorporated in its entirety in this application. 
         [0012]    Some draft gear assemblies employ mechanical springs and steel friction members held in a steel housing that is received in a yoke ( FIG. 5 ). Other draft gear assemblies employ elastomer springs ( FIG. 2 ). The steel housing adds to the weight of the railcar and may rub against the draft sill. Those employing elastomer springs or steel springs or plates for resilient absorption of the impact of buff and draft events may cause rubbing and friction between the springs and the sill. The friction causes heat and fatigue of the draft sill that will lead to premature failure of the draft sill or increased maintenance. There is a need to protect a draft sill to prevent premature failure due to friction on the draft gear assembly and other devices around it. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention addresses the problems incident to train action and yard impact events as it affects the coupling of two cars together and problems with the impact on couplers during operation of the rail car causing wear on the draft sill. The present invention addresses these problems in a manner that is useful in applications such as freight, tank cars, grain cars and coal cars, where it is desirable to protect the railcar, by protecting the integrity of the coupling assembly, from damage due to train action and yard impact events. The present invention may be used in other applications as well. 
         [0014]    In one aspect, the present invention provides a rail car coupling assembly comprising a draft sill, a draft gear assembly and a draft sill liner between the draft gear and the draft sill. The liner for use with railcars having coupler members. The draft sill comprising a front or outboard end, two side walls, a top and a bottom. The draft gear assembly has front and back ends and comprises a yoke, a coupler follower, at least one front resilient member, and at least one back resilient member. The yoke has a back wall, a top wall extending from the back wall toward the front end of the draft gear assembly, and a bottom wall extending from the back wall toward the front end of the draft gear assembly. The coupler follower is positioned between the back wall of the yoke and the front end of the draft gear assembly. The front resilient member is positioned between the front end and the back wall of the yoke. The back resilient member is positioned between the back wall and the back end of the draft sill. The front and back resilient members are compressible. The liner is disposed intermediate the draft gear and the draft sill side walls to hold the draft gear and the side walls in spaced relation to each other and protect the draft sill from wear or damage. 
         [0015]    In another aspect, the present invention provides a liner for use with a railcar having a coupler member, a draft gear, and a draft sill. The draft sill having front and rear stops defining a draft gear pocket to receive at least part of the draft gear assembly. The liner is disposed in the draft gear pocket extending along the length of the pocket between the front stops and rear stops adjacent the inside of each of the two vertical side walls to isolate the draft gear pocket from the draft sill side walls. The liner is adapted to fit in the draft gear pocket by a liner length smaller than the pocket length of the pocket. 
         [0016]    In another aspect of the present invention, the liner is adapted for use in a train car coupling assembly using an E-Type coupler wherein the liner is disposed in the draft gear pocket of a draft sill along the inside of the side walls of the draft sill. The liner extends from adjacent the front stop in the draft gear pocket to a position adjacent the rear stop in the draft gear pocket to isolate the draft gear from the draft sill side wall between the front and rear draft gear stops. The liner also extends from the top of the draft sill to a position adjacent the bottom of the draft sill. A mounting flange on the bottom of the draft sill is adjacent the bottom of the liner wherein carrier plates mounted on the mounting flange of the side wall and extending transversely across the draft sill on each side wall to form a bottom of the draft gear pocket and hold the liner in the pocket. The draft gear comprising a portion in the draft gear pocket. The draft gear is connected to the coupler, wherein the liner is adapted to line the draft sill from the inboard to the outboard ends of the pocket. 
         [0017]    In another aspect of the present invention, the liner is adapted for use in a train car coupling assembly using an F-Type coupler wherein the liner comprises a plurality of liner sheets disposed in the draft gear pocket of a draft sill adjacent to the inside of the each of the side walls of the draft sill. The draft gear is between the liner sheets. Each liner sheet extends from the bottom of the draft sill to a position adjacent the top of the draft sill. The liner sheets also extend from adjacent the front stop in the draft gear pocket to a position adjacent the rear stop in the draft gear pocket on each respective sidewall. A plurality of mounting flange portions extend from the sidewalls. The top of the sill is connected to a top edge of each of the two sidewalls to define an inverted U-shaped draft gear pocket. The top extends between the sidewalls to support the sidewalls in spaced relation to each other. A safety plate is mounted across the bottom of the draft sill at the plurality of mounting flange portions on the bottom edge of the two sidewalls. The safety plate is connected transverse to the draft gear pocket. A draft gear carrier plate is also connected inboard from the safety plate and mounted transversely to the draft sill and the mounting flange portions. 
         [0018]    Various types of draft gear assemblies are in use today. In addition, new draft gear assembly designs are being proposed. Each sits in the draft gear pocket of the draft sill to absorb impact form the train actions and may also have a friction interference with the sidewalls. Each type of draft gear and coupler assembly must integrate with the draft sill to minimize damage to the draft sill and reduce maintenance. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a bottom plan view of a railroad freight car body with a draft sill and coupler in place. 
           [0020]      FIG. 2  is a top plan view of a prior art E-shank draft gear assembly, shown installed in a draft sill and connected to a standard E shank coupler, the coupler and draft gear assembly being shown in a full draft position, and with parts shown in cross-section; 
           [0021]      FIG. 3  is a front perspective view of an E-shank draft gear assembly for use with a draft sill and coupler, with the E-shank draft gear assembly being shown in a pre-shortened condition prior to installation in a draft sill; 
           [0022]      FIG. 4  is a bottom perspective view of an exemplary common draft end sill according to the present invention showing the liner in the draft gear pocket. 
           [0023]      FIG. 5  is a top exploded view of a draft sill having an alternative model draft gear assembly and liner in accordance with the present invention; 
           [0024]      FIG. 6  is a bottom plan view of a draft sill in accordance with the present invention showing the liner installed. 
           [0025]      FIG. 7  is a cut away bottom view of a draft sill having a draft gear installed in accordance with the present invention 
           [0026]      FIG. 8  is a cut away side view of a draft sill having a draft gear installed in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    Referring to  FIG. 1 , a typical cast draft sill  20  is shown mounted to the structure of a railroad freight car  12 . In the mounted position, the cast draft sill  20  is secured to an end sill  44 , the body bolster  38 , and a center sill  46 . The draft sill  20  typically has a top wall that is welded or otherwise affixed to a shear plate that is connected to the bottom of the railway car. The railway car center sill  46  typically runs the length of the car  12  (but on some cars may extend around the periphery of the car depending on car configuration). Buff and draft forces are thus generally transferred between the draft sill  20  structure, the car truck  12  and the center sill  46  of the car  12 . The draft sill  20  has a draft gear  10  mounted within a draft gear pocket  14  and coupler  16  shank  54  extended through the outboard end  21  thereof. A center filler plate  48  is mounted in the center filler plate pocket of the cast draft sill  20 , such as by welding, or may be integrally formed. Center filler plate  48  is receivable within car body  12  at a center plate (not shown). A sole plate  50  connects the body bolster  38  over the cast draft sill  20 . The draft gear pocket  14  has a pair of draft gear carrier members  52  mounted transversely thereto below draft gear cushioning unit  10 . The draft gear carrier members  52  are connected to bottom flanges  56  of the draft sill. The end of the draft sill  20  includes a fishtail piece  58  that has a generally U-shaped opening  60 . 
         [0028]    Referring to  FIG. 2 , a draft gear assembly  10  is installed in a draft sill  20  with an E-type coupler  22  attached to the draft gear assembly  10 . It should be understood that the principles of the present invention are also expected to be applicable to any other type of draft sill  20 , draft gear assembly  10  and coupler  22  in present use or that may come into use in the future. 
         [0029]    Throughout this description, references are made to inboard, forward or front positions or directions, and to outboard, rear, back or rearward positions or directions. The terms outboard, forward and front should be understood to refer to the longitudinally outboard position or direction shown at  2  in  FIG. 2 , toward the outside of the draft sill  20 . The terms inboard, rear, back and rearward should be understood to refer to the longitudinally inboard position or direction toward the center of the freight railcar. In all cases, the draft sill  20  may be cast or fabricated, and may have standard features. The draft sill  20  may have a pair of laterally spaced front stops  14  proximate to the outboard end  21  and a pair of laterally spaced rear stops  16  longitudinally spaced from the front stops  14 . The rear stops  16  and the front stops  14  are on the spaced sidewalls  15 . The front and rear stops  14 ,  16 , side walls  15 , and top  109  ( FIG. 4 ) define a draft gear pocket  18  between them having an inverted U-shape. The draft sill  20  may have other standard features and may be made of standard materials in standard ways. 
         [0030]    Continuing to refer to  FIG. 2 , the draft gear pocket  18  is of the standard AAR size: the longitudinal distance between the inboard faces of the front stops  14  to the outboard faces of the rear stops  16  is 24⅝ inches, shown at pocket length d 1  in  FIG. 2 . When installed, the front end  11  of draft gear assembly  10  extends past the front stops  14  of the draft sill toward the longitudinal outboard end  21  of the draft sill  20  and the back end  13  of the draft gear assembly  10  is at the back stops  16  of the draft sill  20 . The draft gear assembly  10  is connected to the coupler  22  that extends in an outboard direction past the front or outboard end  21  (that is, the striker) of the draft sill  20 . 
         [0031]    Continuing to refer to  FIG. 2 , draft gear  10  comprises resilient members  28 ,  30 , the followers  26 ,  32  and the yoke  24  in the pocket  18 . The walls  15  in the prior art assembly of  FIG. 2  are exposed to damage by contact with or rubbing of the resilient members  28 ,  30  and followers  26 ,  32  as the coupling  22  transfers impacts to the draft gear  10  in the buff and draft modes. The coupler  22  is connected to the draft gear  10  by shank  59  extending through key slot  58  on yoke  24 . The coupler  22  and its shank  59  may have standard features known in the art. 
         [0032]    Referring to  FIG. 3 , the draft gear assembly  10  is shown assembled. The draft gear assembly  10  includes a yoke  24 , a coupler follower  26 , at least one front resilient member  28 , at least one back resilient member  30 , and a rear follower  32 . Each draft gear assembly  10  also includes a center rod  34  and a shortening member  36 . The yoke  24  has a top wall  40 , an integral bottom wall  42  and an integral back wall  44 . The top wall  40  and bottom wall  42  are connected at the back end by the back wall  44 . The top wall  40  and bottom wall  42  extend generally horizontally toward the front end  11  of the draft gear assembly. The back wall  44  extends generally vertically from the top wall  40  to the bottom wall  42 . The yoke  24  also has front members  46  that extend generally vertically between the top wall  40  and bottom wall  42 . 
         [0033]    Continuing to refer to  FIG. 3 , the top wall  40  of each yoke  24  also has a pair of laterally aligned top stops  45  extending downward. The top stops  45  are positioned longitudinally between the back wall  44  and the front end of the yoke  24 . The bottom wall  42  of each yoke of the illustrated embodiment also has a pair of laterally aligned bottom stops  47  extending upward. The bottom stops  47  are positioned longitudinally between the back wall  44  and the front end of the yoke. The stops  45 ,  47  are aligned to provide co-planar inboard-facing stop surfaces, the plane of the stop surfaces being vertical and extending laterally through the yoke for engaging and bearing against the front stop  14 . The entire yoke  24  may comprise a steel casting, or it may be fabricated from separate steel components. The top and bottom walls  40 ,  42  are integral with the back wall  44  as well as with the connecting elements  46  and top and bottom stops  45 , 47 . 
         [0034]    Continuing to refer to  FIG. 3 , the resilient member  30  comprises a plurality of individual ring members  90 . Each ring member  90  comprises two elastomer pads  92  bonded to a central steel ring plate  94 . The elastomer pads  92  of adjacent ring members  90  bear against each other. Each ring member  90  has a hole  96  at its center, each hole having a sufficient diameter for the center rod  34  ( FIG. 2 ) to pass through. The front resilient member  28  comprises a plurality of individual pad members  98  and three intermediate pad members  100 . 
         [0035]    Referring to  FIG. 4 , an E-Type draft sill  20  is shown having a sill liner  99  installed in the draft gear pocket  18 . The sill liner  99  has a front edge  106 , a rear edge  104 , a top  110  and a bottom  108 . The draft liner  99  has a liner length d 2  slightly shorter than the pocket length d 1  of the draft gear pocket  18 . In the preferred embodiment the liner  99  will have a liner length d 2 . The top  110  is flush with the top  109  of the draft sill  20 . The mounting flange  116  extends from the sidewall  15  defining a bottom edge. 
         [0036]    Referring to  FIG. 5  an exploded view of the liner  93  with an alternate type of draft gear  210  such as a Miner type draft gear  210  as available from Miner Enterprises, Inc., 1200 East State Street, PO Box 471, Geneva, Ill. 60134. The draft gear  210  and draft sill  20  are illustrated showing the liner  99  insertable in draft sill  20  and held in place by the carrier plates  52 . The liner  99  is disposed between the draft gear  210  and each of the sidewalls  15  and secured by the carrier plates  52 . The carrier plates  52  comprise a draft gear carrier plate  113  and safety plate  111 , both attached to the bottom of the draft sill  20  at mounting flange  116 . The draft gear assembly  10  comprises a coupler  22  extended into the yoke  24  having the front follower  26 , rear resilient member  30  connected by a pin  59 . The liner  99  comprises a pair of sheets of Ultra High Molecular material such as the POLYSTONE® M or POLYSTONE® MATROX™ product from Roechling Engineering Plastics, P.O. Box 2729, Gastonia, N.C. 28053 ASF Keystone product no. 60320. Alternatively, the liner may be made from an Ultra High Molecular Weight polyethylene such as TIVAR® 88, TIVAR® 1000 or TIVAR® H.O.T., all available through PHS Americas, Poly Hi Solidur, 2710 American Way, Fort Wayne, Ind. 46809, USA. The polymer liner material is purchased in sheets having dimensions of 0.25 inches thick±0.025 in. One sheet is placed on each side of the draft gear  10  having an inside face  112  adjacent to the draft gear  10  and an outside face  114  against the adjacent sidewall  15 . The polymer liner  99  spaces the draft gear  210  from the interior of the sidewall  15 . 
         [0037]    Referring to  FIG. 6 , the draft sill  20  has draft sill liner  99  mounted therein. The liner  99  comprises a first liner sheet  117  adjacent to the first sidewall  15  and second liner sheet  118  on the opposite and facing sidewall  15 . The sheets  117 ,  118  are parallel to sill axis  120 . The front tolerance d 3  between the each sheet  117 ,  118  and the front stop  14  is between 1/16th inch and 5/16th inches. A similar rear tolerance d 4  is measured between each of the sheets  117 ,  118  and the respective rear stop  16 . The liner  99  extends the length of the draft gear pocket  18 . The draft pocket  18  has a width of a length d 5  usually specified around 12⅜ inches. 
         [0038]    Referring to  FIGS. 7 and 8 , the draft sill has the liner  99  comprising liner sheets  117 ,  118  and draft gear  10  mounted therein. In the extended draft mode, shown in  FIG. 7 , the coupling  22  is forced away from the draft sill  20 , the movement of yoke  24  is towards the front end  21  shown in  FIG. 7 . This movement of the coupler  22  causes yoke  24  to move until the front resilient member  28  is compressed which may cause an expansion of pad members  100  causing contact with the liner  99  adjacent side walls  15 . The liner  99  is intermediate the draft gear  10  and the draft sill  20  to separate the draft gear  10  from the sidewall  15 . 
         [0039]    Likewise, in  FIG. 8 , the coupler is moved as in the buff mode, wherein the coupling  22  is forced toward the draft sill  20 , causing the front resilient member  28  to extend and the rear resilient member  30  to compress, thus pushing the rings  90  together and causing expansion of the rear resilient member  30  and possibly force the outer edges of the rings  90  to bear against the liner  99 . The liner  99  is adapted to hold the rings  90  in spaced relation to the sidewall  15 . Draft gear carrier  113  and safety plate  111  are fastened to flange  116  to support the liner  99  and prevent the liner sheets from falling out. The liner sheets  117 ,  118  extend to the top  109  of the draft gear pocket  18 . The liner width d 6  is smaller than or equal to pocket depth d 7 . 
         [0040]    In use the liner  99  is used to isolate the components of the draft gear  10  namely the followers  26 ,  32  and the yoke  24  from the sill wall  15 . Draft gear followers  26  rub against the steel, cast or fabricated, draft sill  20  causing wear and friction. Depending on the wear, the sidewall  15  must be repaired to insure safety of the system. The liner  99  and the draft gear  10  are more easily replaced than the draft sill  20 . To prevent the wear on the draft sill  20 , the liner is slipped in on both sides of the draft gear  10  to space the follower  26  from the sidewalls  15 . The liner sheets  117 ,  118  are placed in the draft gear pocket  18  between the first stop  14  and the second stop  16 . Fasteners are usually not required to hold the sheets  117 ,  118  in place. The carrier plates  52  are attached to the mounting flange to keep the sheets from falling out of the pocket  18 . The carrier plates  52  are removably held in place by fasteners  122  extending through the plates and the flange  116 . No modifications of the draft sill  20  is usually necessary for use with the liner  99  of the present invention. 
         [0041]    The draft sill forms an inverted U-shaped channel having the top attached to the rail car. The sidewalls and the top bound the draft sill interior. The carrier plates removably attached to the mounting flange on the sidewalls closes the bottom. The channel may be an open rectangular shaped cavity for receiving the draft gear therein, and having the liner sheets between the draft gear and the sidewalls. The liner sheets  117 ,  118  are inserted into the draft sill and seated between the front and rear stop to line the draft gear pocket. The draft gear  10  is inserted between the sheets. The draft gear and liner is held in place by the carrier plates  52  fastened to the mounting flange on the sidewall. The liner sheets may wear and need replacement before the draft gear or draft sill need servicing. The carrier plates  52  may be removed to pull out the worn liner sheets. New liner sheets are inserted vertically next to each sidewall in the draft gear pocket. The sheets are placed adjacent to the draft gear and between the draft gear and the respective sidewall so the draft gear is between the liner sheets. The carrier plates  52  are reattached to hold the draft gear and liner sheets in the draft gear pocket. 
         [0042]    When a draft load, that is, a load tending to pull the coupler in a longitudinally outboard direction, greater than about 25,000-30,000 pounds is experienced, the coupler  22  moves longitudinally outboard. The draft system should reach the full draft position when the coupler  22  receives a load of 650,000 pounds, nominally, in the illustrated embodiment. The coupler and the yoke  24  both move in response to a draft impact. The full draft stroke for the coupler and yoke  24  is ¼ (1.25) inches, nominally. The draft sill liner may be used with standard cast or fabricated draft sills. In the full draft position, the coupler pulls against the coupler key  59  which pulls the yoke  24  forward a distance of about 1.25 nominal inches, compressing the front resilient member  28 . Simultaneously, the back resilient member  30  expands by approximately 1.25 inches. 
         [0043]    Although the invention has been described above in connection with particular embodiments and examples, it will be appreciated by those skilled in the art that the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein.