Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a blade set for jaws used in demolition, railroad rail breaking and railroad rail recycling equipment. More particularly, the present invention relates to an opposing blade set having planar rails with recesses extending thereacross and a tapered knife blade adapted in conjunction with an anvil blade to secure a portion of the rail after it is severed. 
     2. Description of Related Art 
     While the present invention relates to demolition and recycling equipment, this equipment is also referred to as construction equipment and scrap handling/processing equipment. The description of demolition equipment, recycling equipment, scrap handling equipment, or construction equipment is not intended to be restrictive to the equipment being referenced. Demolition and recycling equipment, such as heavy duty metal cutting shears, grapples, concrete crushers and rail breakers has been mounted on backhoes powdered by hydraulic cylinders for a variety of jobs in demolition and recycling industries. 
     In the dismantling of an industrial site, railroad rails are often salvaged and it is necessary for efficient handling and transportation of these rails to reduce their length. Rail reduction methods are used to break rail to desirable pre-determined sizes for this purpose. Railroad rails present a unique challenge because the rail is hardened and very rigid. As a result, hardened rails are not amenable to processing using a shear and, therefore, a rail breaker, which bends and breaks the rail, is the most efficient tool for severing these rails. Therefore, rail breakers, which break the rail by bending it, are the most efficient tools for severing these rails. 
       FIG. 1  is prior art, extracted from U.S. Pat. No. 7,354,010, the disclosure of which is hereby incorporated by reference.  FIG. 1  illustrates a jaw set  10  having a bottom jaw  15  with a bottom blade  20  attached thereto and a top jaw  25  with a top blade  30  attached thereto forming a blade set  35 . The bottom blade  20  ( FIG. 2 ) includes two raised support rails  40 ,  45  with a cavity  50  therebetween, while the top jaw  25  includes a top blade  30  having a raised knife rail  55  centrally located above the cavity  50 . The raised support rails  45 ,  50  and the knife rail  55  have generally planar surfaces along their lengths and, as a result, occasionally, the railroad rail slips from between the jaws  15 ,  25  prior to being severed. Additionally, the blades  20 ,  30  sever the railroad rail and both severed ends fall from the rail breaker so that when the process is continued, the rail breaker must reorient and grab the rail again prior to breaking it. It should be noted that, with respect to the pair of jaws  92  illustrated in  FIG. 10   b , the cracker insert  94  does not enter the depression of the cracker insert  96 . 
     A design is needed to permit opposing jaws to more securely grab a railroad rail, making the breaking process more efficient. 
     SUMMARY OF THE INVENTION 
     One embodiment of the invention is directed to a blade set associated with jaws for demolition equipment, wherein at least one jaw rotates relative to the other jaw about a rotational axis within a rotational plane. The blade set has a bottom blade adapted to be secured to the bottom jaw. The bottom blade has a first radial axis therethrough and within the rotational plane and two raised support rails, each having planar surface segments generally perpendicular to the rotational plane and extending parallel to the first radial axis, recesses between the planar surface segments, wherein the recesses extend across the width of the support rail and the recesses of one support rail are aligned with corresponding recesses of the other rail, and a cavity extending between and adjacent to the support rails. A top blade adapted to be secured to the top jaw, a second radial axis therethrough and within the rotational plane, and a raised knife rail having planar surface segments generally perpendicular to the rotational plane and extending parallel to the second radial axis, and recesses between the planar surface segments, wherein the recesses extend across the width of the knife rail. The width of the knife rail at the planar surface segments is less than the width at the opening of the cavity. The top blade and the bottom blade are symmetric about the rotational plane. 
     Another embodiment of the subject invention is directed to a jaw set with the blade set just described. 
     Yet another embodiment of the subject invention is directed to a method of processing a railroad rail using a rail breaker demolition tool having a jaw set with a bottom jaw with a bottom blade and a top jaw with a top blade. The blades have planar surfaces and recesses. The bottom blade has support rails with planar surfaces that are spaced apart by a cavity. The top blade has a knife rail with a planar surface, wherein the width of the knife rail increases linearly away from the planar surface. The method comprising the steps of a) holding the rail between the jaws such that the bottom blade provides spaced apart support to the rail, b) advancing the top jaw and bottom jaw together such that the top jaw applies a load on the rail midway between the spaced apart support of the bottom blade until the rail breaks and a severed portion is ejected from the jaws, and c) further advancing the jaws together until the wider portion of the knife rail compresses the remaining portion of the rail against the cavity walls to retain the remaining portion within the clamped jaw set. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is prior art and is a side view of a jaw set; 
         FIG. 2  is prior art and is a view of the jaw set in  FIG. 1  along lines “ 2 - 2 ”; 
         FIG. 3  is a perspective view of the jaw set in accordance with the subject invention; 
         FIG. 3A  is a perspective view of the top blade in  FIG. 3 , but rotated to show features of the raised knife rail; 
         FIG. 4  is a side view of the jaw set illustrated in  FIG. 3 ; 
         FIG. 5  is an end view of the jaw set illustrated in  FIG. 3 ; 
         FIG. 6  is an end view of the jaw set illustrated in  FIG. 5  with the railroad rail illustrated in broken cross-section and with the connections between the blades and the jaws shown; 
         FIGS. 7A-7D  illustrate the sequence of the rail breaker as it severs a railroad rail; 
         FIG. 8  is a side view of the jaw set in the closed position illustrating the relative position of the recesses between the jaws; and 
         FIG. 9  is a perspective view of the bottom jaw illustrating the manner by which a bottom blade is retained. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 3  illustrates a perspective view of a jaw set  110  for demolition equipment having a bottom jaw  115  pivotally connected to a top jaw  125 . A bottom blade  120  is secured to the bottom jaw  115 . The bottom blade  120  has a first radial axis R 1  therethrough, wherein the first radial axis R 1  is within a rotational plane RP of the jaws  115 ,  125 . The bottom blade  120  has two raised support rails  140 ,  145 . Each raised support rail  140 ,  145 , as explained with respect to support rail  140 , includes planar surface segments  160  (see also  FIG. 4 ), wherein the planar surface segments  160  are generally perpendicular to the rotational plane RP and extend along the bottom blade  120  parallel to the first radial axis R 1  ( FIG. 3 ). Each support rail  140 ,  145 , as illustrated in support rail  140 , has recesses  165  between the planar surface segments  160 . The recesses  165  extend across the width W 1  of the raised support rail  145 . The recesses  165  of one support rail  140  are aligned with the corresponding recesses  170  of the other raised support rail  145 . A cavity  175  extends between and adjacent to the raised support rails  140 ,  145 . 
     Relative pivotal motion between the bottom jaw  115  and the top jaw  125  is achieved when both jaws  115 ,  125  rotatably move or when one jaw is stationary and the other jaw rotates relative to the stationary jaw. As an example, bottom jaw  115  may be stationary and top jaw  125  may rotate. 
     A top blade  130  is secured to the top jaw  125 . The top blade  130  has a second radial axis R 2  running therethrough and within the rotational plane RP. The top blade  130  additionally includes a raised knife rail  155  having planar surface segments  180  ( FIG. 3   a ) generally perpendicular to the rotational plane RP ( FIG. 3 ) and extending parallel to the second radial axis R 2 . The raised knife rail  155  further includes recesses  185  between the planar surface segments  180 , wherein the recesses  185  extend across the width W 2  of the knife rail  155 . Directing attention to  FIG. 5 , the width W 2  of the knife rail at the planar surface segment  160  is less than the overall width W 3  of the cavity  175 . 
     The top blade  130  and the bottom blade  120  are symmetric about the rotational plane RP ( FIG. 5 ). 
     As illustrated in  FIGS. 3 and 5 , the bottom blade  120  and the top blade  130  are U-shaped to provide overlapping matching surfaces on the respective bottom jaw  115  and top jaw  125 , such that the bottom blade and the top blade are supported by the jaws  115 ,  125  on three sides. For example, directing attention to  FIG. 5 , the bottom blade  120  is supported by the bottom jaw  115  along support surfaces  122   a ,  122   b , and  122   c . Additionally, the top blade  130  is supported by the top jaw  125  along three support surfaces  132   a ,  132   b , and  132   c.    
     Directing attention to  FIG. 6 , the width W 2  of the knife rail  155  at the planar surface  180  is between 10-40% of the width W 3  of the cavity  175  and preferably, the width W 2  at the planar surface  180  of the knife rail  155  is approximately 20% of the width W 3  of the cavity  175 . 
     In addition to effectively breaking railroad rails, the subject jaw set  110  may also be used to hold one side of a railroad rail after it has been severed. In particular,  FIGS. 7A-7D  show the progression of severing a railroad rail  112  into two parts  112   a ,  112   b . In  FIG. 7A , the rail  112  is placed between the bottom jaw  115  and the top jaw  125 . As illustrated in  FIG. 7B , the bottom jaw  115  and the top jaw  125  are urged toward each other at which time the rail  112  begins to deflect. As previously mentioned, the material used for the rail is relatively brittle and, as a result, the rail  112  will deflect only a small degree before the rail breaks as illustrated in  FIG. 7C . 
     Briefly returning to  FIGS. 5 and 6 , the rail  112  is supported by raised rail support  140  and raised rail support  145  and is unsupported along the width W 3  of the cavity  175 . The top jaw  125  applies a load to the rail  112  approximately midway between the width W 3  of the cavity  175  to produce maximum stresses on the rail  112 . It should be appreciated that the width W 3  of the cavity  175  is made possible because the bottom blade  120  is wider than the bottom jaw  115  supporting it. This is achieved by the U-shaped connections between the bottom blade  120  and the bottom jaw  115 . 
     Returning to  FIG. 7C , with a sufficient force supplied by the top jaw  125  against the rail  112 , the rail breaks into two parts  112   a ,  112   b , as illustrated in  FIG. 7D . However, in the instances where the rail  112  is relatively long, then it is possible to configure the top blade  130  and the cavity  175 , such that after the rail  112  is severed, the longer remaining half  112   a  may essentially be clamped between the top blade  130  and the bottom blade  120  so that the remaining rail section  112   a  may be positioned for an additional cut, or in the alternative, may be transported to a different location. In particular and directing attention to  FIG. 6 , the width W 2  of the knife rail  155  extending away from the planar surface  180  remains generally constant in the region  187 , however, thereafter, the width increases, as illustrated by the width in region  189  adjacent to region  187 . Furthermore, the width in the region  189  may increase linearly and may increase to the width W 4  equal to the width W 3  of the cavity  175 . 
     The knife rail  155  in the region  189  as it increases linearly forms an angle A with a line perpendicular to the rotational plane RP of between 30-60 degrees and preferably 45 degrees. Additionally, the cavity  175  may have a depth D 1  of approximately 50-150% of the width W 2  of the knife rail  155  at the planar surface segment  180 . The cavity  175  may have a shape that is generally oval, however, regardless of the shape, it is important that the surfaces of the cavity  175  are continuous and do not intersect with sharp corners that produce high stress concentrations. 
     Directing attention to  FIG. 4 , each recess  165  associated with the bottom blade  120  has a depth D 2  that is approximately 20-70% of the width W 1  ( FIG. 5 ) of the rail support  145 . Additionally, the length L 2  of the recess  165  is approximately 20-70% of the width W 1  of the support rail  140 . It is important to note that the length L 4  of the planar recess segments  160  may be greater than the length L 2  of the recesses  165 . The purpose of this is to maximize the wear capacity of the bottom blade  120 . 
     In a similar fashion, with respect to the top blade  130 , each recess  185  has a depth D 3  and the depth D 3  is approximately 20-70% of the width W 3  ( FIG. 5 ) of the planar surface segment  160  of the knife rail  155 . Furthermore, the length L 3  of each recess is approximately 20-70% of the width W 3  at the planar surface segment  160  of the knife rail  155 . Finally, the length L 5  of the planar surface segments  180  of the top blade  130  may be greater than the length L 3  of the recesses  185  of the top blade  130 . Once again, the purpose of this is to increase the longevity of the wear surfaces. 
     Again directing attention to  FIG. 4 , although in each instance the recesses  165 ,  185  of the bottom rail  120  and the top rail  135  are radiused, they may have different shapes, however, any intersection of surfaces should have radiused corners to minimize stress concentration factors. As illustrated in  FIG. 4 , both the bottom rail and the top rail have recesses  165 ,  185  that are generally arcuate in shape. 
       FIG. 8  illustrates a jaw set  110  with a bottom jaw  115  and a top jaw  125  in a closed position, such that the cavity  175  of the bottom blade  120  receives the radial knife rail  155 . It should be noted, however, that the recesses  165  of the bottom blade  120  are, for the most part, shifted along the radial axis R 1  relative to the recesses  185  of the top blade  130  with respect to the radial axis R 2 . Under certain circumstances, this off-set feature may enhance the ability of the bottom blade  120  and top blade  130  to hold and secure railroad rails. 
       FIG. 4  and  FIG. 8  also illustrate the relative position of the bottom blade  120  and the top blade  130  in the partially opened position ( FIG. 4 ) and in the completely closed position ( FIG. 8 ). Although the rail to be broken is brittle, depending upon the size of the rail  112 , the range of travel of the blades  120 ,  130  toward one another may be more or less. To break the rail  112 , it must be sufficiently deflected to produce the stresses which cause failure and breakage. In certain instances, the rail  112  may be small and oriented such that the blades  120 ,  130  are nearly closed when the rail  112  is initially grabbed by the blades  120 ,  130 . Under these circumstances, the travel of the blades  120 ,  130  is such that they overlap, as shown in  FIG. 8 . In particular, the travel of the blades  120 ,  130  may be so great in the closed position that the raised knife rail  155  enters the cavity  175  of the bottom blade  120 . With this arrangement, the raised knife rail  155  may compress a rail  112  within the cavity  175 . 
     Directing attention to  FIGS. 3 and 9 , the bottom blade  120  is removably secured to the bottom jaw  115  and the top blade  130  is removably attached to the top jaw  125 . The arrangement for attaching each of these blades to its respective jaw is similar and, for that reason, the attachment of the bottom blade  120  to the bottom jaw  115  will be discussed with attention directed to  FIGS. 6 and 9 . 
     The bottom blade  120  includes holding lugs  190  and a stabilizer  195  protruding from the bottom blade  120 . Extending through the holding lugs  190  are bores  192  adapted to accept bolts  230 . The bottom jaw  115  has receivers  200  to accept the holding lugs  190  and a cradle  205  to accept the stabilizer  195 . The holding lugs  190  extend on both sides of stiffening bars  210  extending along the lower jaw  115 . The stiffening bars also have bores  212  aligned with bores  192  to accept bolts  230 . Additionally, as illustrated in  FIG. 6 , below the holding lugs  190  are stabilizer wings  215  having surfaces  220  which abut the lower jaw surfaces  225  ( FIG. 9 ) to provide additional stiffness and to resist twisting between the bottom blade  120  and the bottom jaw  115  when forces are applied to the bottom blade  120 . As illustrated in  FIG. 6 , bolts  230  pass through the holding lugs  190  and the stiffening bars  210  to secure the bottom blade  120  to the bottom jaw  115 . It is possible to include sleeves around the bolts  230  for additional strength. 
     It should be appreciated that this arrangement just discussed, with respect to the bottom blade  120  and its attachment to the bottom jaw  115 , is also applicable to the attachment of the top blade  130  to the top jaw  125 . 
     As illustrated in  FIGS. 7C and 7D , when the railroad rail  112  is sufficiently stressed, due to the brittle nature of the rail  112 , it will bend only slightly before breaking. The energy released when the rail  112  breaks, typically manifests itself in energy transmitted to the severed parts. As shown in  FIG. 7D , while segment  112   a  is retained by the jaws  115 ,  125 , segment  112   b  becomes an airborne projectile moving in a direction away from the bottom jaw  115 . For that reason, during this cutting operation, for safety, the bottom jaw  115  of the jaw set  110  must be closest to the operator, while the top jaw  125  must be furthest from the operator. To insure this, the exterior surface  235  of the top jaw  125  is marked with indicia  240  to assist the operator in the proper orientation of the jaw set  110  during operation. In one embodiment, the indicia  240  may be a highly visible paint covering a substantial portion of the top jaw  125 , such that the highly visible paint and, therefore, the top jaw  125  should not be visible to the operator during a cutting operation. Preferably, the highly visible paint is red paint. As a result, so long as during the cutting operation the operator does not see the indicia on the top jaw  125 , then there is assurance that the path of segment  112   b , as it becomes a projectile, will be directed away from the operator. 
     A method of processing a railroad rail  112  using a rail breaker demolition tool having a jaw set  110  with a bottom jaw  115  having a bottom blade  120 , and a top jaw  125  having a top blade  130 , involves the steps as illustrated in  FIGS. 7A-7D  of holding the rail  112  between the bottom jaw  115  and the top jaw  125 , such that the bottom blade  120  of the bottom jaw  115  provides spaced-apart support using the raised support rail  140  and raised support rail  145 . As illustrated in  FIG. 7B , the top jaw  125  and the bottom jaw  115  are advanced together, such that the top jaw  125  applies a load on the rail  112  midway between the spaced-apart support of the bottom blade  120  until the rail  112  breaks ( FIG. 7C ) and a severed portion  112   b  ( FIG. 7D ) is ejected from the jaws  115 ,  125 . The jaws  115 ,  125  are further advanced together until the wider portion  189  of the top blade  130  compresses the remaining portion of the rail  112   a  against the walls of the cavity  175  to retain the remaining portion  112   a  within the clamped jaw set  110 . Additionally, when the exterior surface  235  of the top jaw  125  is marked with indicia  240 , the method of processing may further include the step of orienting the jaw set  110  such that the indicia  240  of the top jaw  125  is furthermost away from the machine operator, such that any severed part  112   b  may be expelled in a direction away from the operator. 
     What has so far been described is the application of the jaw set  110  to break railroad rails. While this is the primary application for this jaw set  110 , it should be appreciated that the jaw set  110  may have other applications including, for example, compressing hollow pipe either before or after it is cut with a shear to minimize the volume the pipe occupies, thereby increasing the efficiency of stockpiling and transporting such parts. 
     Furthermore, it should be appreciated that while the bottom blade  120  has been described as removably attached to the bottom jaw  115  and the top blade  130  has been described as removably attached to the top jaw  125 , each blade and its respective jaw may be formed as a unified integral part, such that the jaw and blade would be integral with one another. 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.

Technology Category: e