Patent Publication Number: US-7909293-B2

Title: Low profile derail

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a utility application derived from provisional application Ser. No. 61/091,839 filed Aug. 26, 2008 entitled “Low Profile Derail” which is incorporated herewith and for which priority is claimed. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to railway safety equipment, namely, derails which are commonly used for derailing railed vehicles including locomotives, railroad cars and the like, which may be undesirably moving along railroad tracks, normally at a relatively low speed. There are many types of derails, known in the rail industry, which have been used for many years. Certain types of derails are substantially permanently fixed to one rail of a pair of railroad track rails and various methods may be used to move the derail between an operative position and an inoperative position. Some derails are relatively light in weight so as to be portable and are not movable between operative and inoperative positions. 
     At least in connection with certain types of derails, the railway industry historically required that the highest point of a derail was not to be higher than four inches measured from the top of the rail upon which the derail was affixed. A principal reason for this requirement was that the pilot (sometimes called a “cowcatcher”) of a railway locomotive must be allowed to clear the highest point of the derail so that a heavy locomotive&#39;s pilot did not sweep, push or knock off the entire derail when the locomotive was undesirably moving at a relatively low speed, such as up to 10 miles per hour. If the derail is moved out of derailing position by the pilot, the derail becomes ineffective and the undesirably moving locomotive may cause serious damage to other locomotives or railway cars, such as at a railroad yard, or even cause serious injury or death to railway workers in the area. 
     Relatively recently, the railway industry changed its standards to require that certain derails could not have its highest point more than three inches above the upper surface of a railroad rail upon which the derail is affixed. In essence, certain existing derails higher than or just at three inches above the rail could be unsafe to use, particularly in connection with undesirably moving heavy locomotives, because the entire derail could be forced off the track by the pilot of the locomotive before the lead wheel of the undesirably moving locomotive could be engaged by the derail, thereby causing the undesirably moving locomotive to continue moving unsafely rather than allowing the derail to remain in place and cause a safe derailment of the locomotive if needed. 
     SUMMARY OF THE INVENTION 
     The subject of this invention is a redesign of the derails as disclosed in U.S. Pat. No. 4,165,060 and particularly in U.S. Pat. No. 6,105,906, the disclosures of which are incorporated herein by reference. More specifically, the invention herein is a redesign and an improvement over the embodiment of FIGS. 10-13 of the &#39;906 patent and is designed to assure that the pilot (cow catcher) of an undesirably moving locomotive does not move, such as by forcing or pushing, the derail off the rail so the derail is effective in causing a safe derailment. 
     The present invention is directed to a low profile, portable derail, such as shown in the above-mentioned patents (particularly the embodiment of FIGS. 10-13 of the &#39;906 patent) and which is particularly designed to have a height of less than three inches, preferably at least 2¾″, from the highest point of the derail down to the upper surface of the track upon which the derail is mounted. Preferably, a clearance of at least ¼″ is provided by the maximum height of the derail between the lowest point of the locomotive pilot and the derail. Since the derail is designed to derail a moving locomotive having a pilot at the lower front-end thereof, the derail must have high strength capacity to effectively derail the undesirably moving very heavy locomotive(s) which could move at speeds as high as 10 miles per hour. Since the pilot of the locomotive may be as low as three inches above the rail upon which it is moving, the design of the derail herein cannot be pushed or forced off the rail by the pilot of the locomotive before the lead wheel approaches the derail. The derail of the present invention, although being particularly effective to derail locomotives, will also be effective in derailing undesirably moving railway cars. 
     In actual testing, two locomotives were ganged or attached together and were caused to move at speeds up to 10 miles per hour. In this test, one embodiment of the present invention was effective in derailing the locomotive. However, the initial testing, although effective, resulted in an improved redesign of the derail that was first tested. Apparent potential problem areas of the tested design were found. Improvements were made in a second and later preferred embodiment of the invention. 
     There is a need in the railroad industry to provide a derail, preferably relatively light in weight, to be portable and yet be effective to derail an undesirably moving locomotive, having a weight of approximately 350,000 pounds or even two such locomotives, at about 950,000 pounds connected together, wherein the locomotive&#39;s pilot will clear the derail of the present invention used on the track without the derail being forced off by the pilot of the locomotive before the lead wheel reaches the derail. The derail must be less than three inches in height above the upper surface of the track, preferably providing a ¼″ clearance between the pilot and the derail, and yet be strong and sturdy enough to effectively derail 350,000 pounds of one locomotive or, possibly, even two connected locomotives moving at speeds up to 10 miles per hour. 
     The above-mentioned need for a portable derail sufficiently strong to derail one or two locomotives at speeds up to 10 miles per hour is accomplished by an improved derail design. The low profile derail (less than three inches in overall height clearance from the top of the rail) includes an elongated derail shoe in direct contact with and completely covering the entire length of substantially the entire upper surface area portion of the one rail upon which the derail is mounted. The elongated derail shoe has a wheel entrance end and a wheel exit end. An upright derail bar is securely mounted on the derail shoe and is angled outwardly, that is, towards the field side of the rail from the wheel entrance end to the wheel exit end of the elongated derail shoe which rests upon the one rail. The derail assembly further includes at least two longitudinally spaced one-piece rigid hooks which are fixedly secured to the derail shoe one side thereof at the wheel entrance end and at the wheel exit end. Securing members, such as screws, are operatively mounted on the hooks for selectively securing the derail assembly on the outer side of one side of the one rail. A clamp assembly is secured to the derail shoe on the opposite side of the derail shoe from the hooks. The hooks, the securing members and the clamp assembly cooperate to secure the entire derail assembly to the one track. Preferably, a reinforcing portion is provided on the exit hook for reinforcing the critical exit end of the derail bar for assuring successful derailing of the lead wheel of the moving locomotive or other moving railroad car. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are incorporated into and are a part of the description of the invention. The drawings illustrate certain embodiments of the present invention and serve to explain and describe embodiments of the invention. The drawings are not to be construed as limiting the scope of the invention, but are intended to assist in the description of the invention. 
       Referring to the drawings: 
         FIG. 1  is an illustration showing the front of a locomotive with a pilot located in the front lower portion thereof and showing a derail assembly affixed to one rail of a pair of railroad tracks upon which the locomotive is moving; 
         FIG. 2  is a perspective view showing one embodiment of the derail assembly of the present invention mounted on the one rail illustrated in  FIG. 1 ; 
         FIG. 3  is an illustration of a portion of the wheel assembly of the locomotive of  FIG. 1  showing a front wheel approaching the derail assembly of the present invention; 
         FIG. 4  is a top plan view of the derail assembly of  FIGS. 1-3  with a rail shown in hidden view lines; 
         FIG. 5  is an end elevational view of the derail assembly of  FIG. 4 ; 
         FIG. 6  is a side elevational view of the derail assembly of  FIGS. 4 and 5 ; 
         FIG. 7  is a pictorial view of a derail assembly made in accordance with a second embodiment of the present invention; 
         FIG. 8  is a side elevational view of the derail assembly embodiment of  FIG. 7  of the present invention; 
         FIG. 9  is an end elevational view of the embodiment of the derail assembly illustrated in  FIGS. 7 and 8 ; 
         FIG. 10  is a detail side view of the exit and of one screw hook used in the derail assembly embodied in  FIGS. 7-9 ; and 
         FIG. 11  is an end elevational view of the screw hook of  FIG. 10 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Referring to  FIGS. 1-3  of the attached drawings, the manner of using the derail assembly, general  20 , is shown. Referring to  FIG. 1 , the front of a locomotive L is shown as it moves along a pair of conventional spaced steel railroad track rails R which are fixedly supported in a conventional manner upon conventional railroad ties T. The ties T are mounted transverse to the elongated rails R upon which the locomotive L is moving. The front lower portion of the locomotive L is shown having a pilot P (historically formerly known as a cowcatcher). Under relatively new railroad industry specifications, the lowest point of the pilot P may now having a clearance of only 3″ above the top of the rail R. If the locomotive L is moving undesirably at speeds above 5 MPH, and up to 10 MPH, the derail  20 , as shown in  FIG. 1 , must be lower in height, such as 2¾″ to preferably give at least ¼″ clearance below the lowest point of the pilot P to the highest point of the derail  20 . Otherwise the pilot P could simply push or force the derail assembly  20  off the rail R upon which derail  20  is affixed. If this occurs, the derail  20  would be useless in effecting a desired derailment of an undesirably moving locomotive L. 
     Again, referring to  FIG. 1 , the derail assembly  20  is shown mounted on the rail R. The derail  20  is positioned in such a manner as to cause a derailment of the undesirably moving locomotive L to the right side of the moving locomotive L for derailment to the field side of the spaced rails R. (The space between the rails R is known as the gage side.) 
     Referring to  FIG. 2 , the derail assembly  20  is shown mounted upon a rail R. The derail assembly  20  includes a steel, rigid derail shoe plate  22  which is mounted directly upon and rests upon and substantially completely covers the entire upper surface portion of the rail R to which the derail assembly  20  is attached. A wheel deflecting bar  24  is rigidly fixed in a substantially upright position, preferably vertical, on the upper surface of the derail shoe plate  22 . The bar  24  is mounted at an angle effective to engage the wheel W, as shown in  FIG. 3 , which is the lead wheel W of the moving locomotive L. The deflecting  24  is angled outwardly from the entrance end to the exit end of the derail  20  at between 11-28 degrees. 
     The derail assembly  20  further includes an entrance derail hook  26  and an exit derail hook  27 . The derail hooks  26  and  27  are rigidly secured to the derail shoe plate  22  and are spaced at opposite ends of the plate  22 . The hooks  26  and  27  are provided so as to secure one side of the derail assembly  20  to the field or outer side of the rail R. Again referring to  FIG. 2 , the derail assembly  20  further includes an adjustable clamp assembly  28  that is operatively secured to the plate  22  and is designed to secure the opposite side or gage side of the derail assembly  20  to the rail R. 
     Although not shown in  FIGS. 1-2 , a rigid upright bracing assembly, generally  38 , is shown in  FIGS. 3 ,  5  and  6 , is mounted on the underside of the shoe plate  22  of the derail assembly  20  and is designed to vertically support the derail assembly  20  as the heavy load of the front wheel W of the moving locomotive L comes into forcible contact with the assembly  20 , and specifically the deflecting bar  24 . 
     Referring to  FIG. 3 , the lead wheel W of the moving locomotive L, which may be moving undesirably at speeds of up to 10 miles per hour, is effectively derailed by the derail assembly  20  since the pilot P, which may be as low as 3″ above the upper surface of the rail, has cleared the derail assembly  20  which is less than 3″ above the upper surface of the rail R, preferably 2¾″ above the rail R, to provide a clearance of at least ¼″. 
     First Derail— FIGS. 4-6   
     Referring to  FIGS. 4-6 , the derail embodiment  20  is shown in somewhat greater detail. Some common details are found in U.S. Pat. No. 6,105,906, which is incorporated herein by reference. As previously indicated, the upright deflecting bar  24  is effectively angled outwardly to engage the moving lead wheel W of the locomotive L since the pilot P of the locomotive L has cleared the highest point of the derail assembly  20 , thereby derailing the moving locomotive L to the field side of the rail R. 
     Referring to  FIGS. 4-6 . the entrance derail hook  26  is rigidly secured to the derail shoe plate  22 , as by welding, along its lower surface while the inner end or gage side end  32  of the entrance derail hook  26  is welded to the outer or field side face of the entrance end of the deflecting bar  24 . 
     The derail shoe  22  is a rigid heavy duty plate that is welded to the lower edge of the upright deflecting bar  24  along the entire length of the bar  24  along the field side face of the deflecting bar  24 . The field side of the derail shoe plate  22  has a unitary, upright, downwardly extending flange  35  that covers the outer edge of the upper flange of rail R, as best seen in  FIG. 2 . The flange  35  as seen best in  FIG. 2 , and the substantially complete coverage of the adjacent upper surface portion of the rail R by the derail shoe on plate  22  provides significantly greater strength to the derail plate  22  to thereby significantly strengthen the entire derail  20 . The plate  22  and flange  35  are stronger than the ultralight embodiment of FIGS. 10-13 of the &#39;906 patent and such a design feature is important to derail an undesirably moving locomotive L. As seen best in  FIG. 4 , towards the exit end of the upright deflecting bar  24 , upright support plates  34  are rigidly positioned against the upright of the derail bar  24 . These upright plates  34  are also welded along the lower edges thereof to the derail shoe plate  22  while their upright edges are welded to the inner side or gage side face of the deflecting bar  24  to provide added strength to the deflecting bar  24  as the wheel W has been engaged by the bar  24  and cause the controlled derailment. 
     Referring to  FIG. 5 , the derail assembly  20  is shown resting upon a rail R. A clamp assembly  36  is securely and operatively carried by a support assembly  38 . The clamp  36  includes an upright end plate  40  which is designed to bear against the outer upright face of the upper flange of the rail R. The clamp  36  on the gage side of the rail R and the longitudinally spaced screw hook blocks  26  and  27 , on the field side, cooperate to secure the derail  20  to the rail R. Although two hook blocks  26  and  27  are shown in the drawing, for further strengthening, one or more additional hook blocks could be provided. 
     Referring again to  FIGS. 4-6 , the hook block assembly  26  and the hook block assembly  27  each have an inwardly and downwardly angled portion that threadably receives a screw  42  that is designed to be rotated generally upwardly to bear against the lower surface of the upper flange of the rail R. In assembling the derail assembly  22  to the rail R, it is preferred that the screws  42  in the hook blocks  26  and  27  first be adjusted to bear against the lower surface of the upper flange of the rail R and then the clamp  36  is adjusted to cause the end plate  40  to bear firmly against the upright outer surface of the upper flange of the rail R. The screws  42  are then firmly tightened the rail R. In  FIG. 5 , there is shown an upright pole P for a warning flag (not shown) that is merely an identifying signal that lets workers know that the derail  20  is in place. The pole P and flag assembly have no operative function relative to the invention described herein. 
     The upright rigid support assembly  38  is rigidly secured to the underside of the derail shoe plate  22  on the gage side of the derail assembly  20  as seen best in  FIG. 5 . The lower surface of the upwardly angled support  38  has teeth  39  that are designed to bear against the upper side corner of a transverse railroad tie T so as to enable the outer portion of the derail assembly  20  to be vertically supported by the support  38  during derailment of a locomotive L. Multiple teeth  39  are provided so that the derail plate  22  can be adjusted to a selected position to rest against the upper surface of the upper flange of the rail R. 
     The derail assembly  20  differs from U.S. Pat. No. 6,105,906 primarily in the fact that the derail shoe plate  22  is not only adjacent the surface of the rail flange but it covers substantially the entire upper surface area of the rail R. The unitary flange  35  portion of the plate  22  provides significant further strength. Upright supports  34  are provided on the gage side of the deflecting bar  24  to further strengthen the assembly  20 . The weight of a tested derail  20  was about 35 pounds while the weight of the “ultralight” derail of the &#39;906 patent was about 28 pounds. In other words, the plate  22  is continuous and rigid and does not include a cut-out portion as shown in FIG. 13 of the &#39;906 patent. In testing, it was found that the derail  20 , as shown and discussed above, did provide enough strength to cause a derailment during an actual test. Certain weaknesses in the test derail resulted in further improvements to be discussed relative to the derail, general  48 , shown in  FIGS. 7-11 . 
     Strengthened Derail Embodied in  FIGS. 7-11   
     The improved derail embodiment  48  is shown in  FIGS. 7-11  which includes a derail shoe plate  50  which, like the derail plate  22  of the derail  20 , substantially covers the entire upper surface area of the rail R upon which the assembly  50  is secured. The plate  50  includes a unitary downturned flange  51 . The heavy duty derail shoe plate  50  and flange  51  provide significant stability and rigidity to the assembly  48  to better resist torquing resulting from the heavy weight of the front end of an undesirably moving locomotive L during a controlled derailment. 
     A deflecting bar  52  is rigidly secured as by welding to the upper surface of the derail shoe  50  and is angled outwardly, that is, from the gage side, toward the field side of the rail R. The mounting of the derail assembly  48  upon the rail R is substantially the same as the mounting of the derail assembly  20  upon the rail R, as discussed in  FIGS. 1-6 . 
     Upright support plates  60  are secured by welding to the upper surface of the plate  50  and to the inner upright surface of the deflecting bar  52  in order to support the inner side or gage side of the deflecting bar  52 . The deflecting bar support plates  60  are preferably about ⅜″ thick as opposed to the 3/16″ thickness of the supports  34  of the derail  20 . A clamp assembly  62  is located on the field side of the assembly  62  and is securely attached to the derail shoe plate  50 . The clamp assembly  62  is supported on the derail assembly  48  in substantially the same manner as with the derail embodiment  20  of  FIGS. 4-6 . The clamp assembly  62  includes an end plate (not shown), which bears against the outer upright face of the upper flange of the rail R as like the derail embodiment  20  of  FIGS. 4-6 . 
     Like the embodiment  20  of  FIGS. 4-6 , the derail assembly  48  also includes an entrance derail hook  54  and an exit derail hook  56 . Each hook  54  or  56  is rigidly secured, as by welding, to the upper surface of the derail shoe  50 . An upright bracing assembly  58 , is designed to be positioned on the gage side of the derail assembly  20 . The bracing assembly  58  is rigidly constructed in order to better support the heavy weight of a moving locomotive L as it is being derailed. More specifically, the bracing assembly  58  of the embodiment  48  is doubled in thickness from the bracing assembly  20 , that is, the brace is ⅜″ thick versus the 3/16″ thickness of the brace  38  of the first derail assembly  20 . 
     A further difference between the derail embodiment  20  of  FIGS. 4-6  and the derail embodiment  48  of  FIGS. 7-9  is found in the design of both the entrance hook  54  and the exit hook  56 . Referring to  FIGS. 7 and 9 , the entrance end hook  54  includes an inwardly facing slightly downwardly angled portion  64 , a unitary upright outer portion  66 , and an inwardly directed or gage directed unitary upper portion  68 , which is directed straight inwardly. The upper portion  68 , for substantially its entire length, is secured to the upper surface of the derail shoe  52  such as by welding. In contrast to the embodiment  20  of  FIGS. 4-6 , the embodiment of  FIG. 7  provides a stronger interconnection between the deflecting bar  52  and the upper portion  68  of the entrance hook  54 . As seen in  FIG. 7 , the upper portion  68  passes beneath a cut-out portion of the entrance end of the deflecting bar  52  and passes externally beyond the inner surface of the upright deflecting bar  52 . The entrance hook  54  is welded along and to the front surface of the deflecting bar  52 , and is also welded along the rear surface of the deflecting bar  52  at the outer portion of the bar  52 . 
     Referring to  FIGS. 7 ,  10  and  11 , the exit hook  56  includes a lower, inwardly and downwardly angled portion  70 , a unitary upright portion  72 , and a substantially horizontal inwardly directed unitary upper portion  74 . In contrast to the entrance hook  54 , the exit hook  56  includes a unitary upwardly directed upright portion  76 . The exit hook  56  generally has an S-shape. The upright portion  76  provides greater rigidity for the exit hook  56  by supporting the exit end of the deflecting bar  52  to better assure derailment of a moving locomotive. The upright portion  76  is welded to the inner face of the deflecting bar  52  to provide added rigidity to the exit hook  56 . Particularly in the case of a heavy locomotive, the exit end of the derail  48  must be exceptionally strong to assure effective derailing of a locomotive L to the field side of the rail R when the wheel W engages the derail  48 . In effect, the exit end of the derail assembly  48  takes the highest level of weight or force from the wheel W of the heavy, moving locomotive L during a derailment. 
     The derail assembly  48  of  FIGS. 7-11  is secured to a rail R in substantially the same manner as previously described. First, the screws  78  carried by the entrance hook  54  and exit hook  56  are rotated upwardly so that the upper ends of the screws  78  bear against the lower flange of the rail R to secure one side of the derail  48  to the rail R. The clamp assembly  62  is then adjusted by rotation to cause the end plate (not shown in  FIG. 7 ) to bear against the outward upper surface of the upper flange of the rail R as seen best in  FIG. 5  on the opposite side of the rail R from the hooks  54  and  56 . The screws  78  are then tightened against the rail R. The clamp assembly  62  and the hooks  54  all cooperate to securely hold the derail  48  in place as a moving locomotive L is being derailed by the derail assembly  48 . 
     The derail  48  of  FIGS. 7-11  is generally more robust in design than the derail  20 , as described above. The overall weight of the derail  48  is about 42 pounds versus the 35 pounds of the derail  20 , and the 28 pounds of the ultralight derail of the &#39;906 patent. This generally robust design of the derail  20  thereby provides greater assurance that the desired derailing of an undesirably moving locomotive L or two ganged locomotives L will be accomplished. 
     While in the foregoing, there has been provided a detailed description of embodiments of the present invention, it should be recognized to those skilled in the art that the described embodiments may be altered or amended without departing from the spirit or scope of the invention defined in the accompanying claims.