The present invention comprises a tamping tool comprising a shank and a blade, with the blade having various arrangements of wear-resistant material affixed to the face of the blade by means of brazing, soldering, gluing or other method. Additionally, some arrangements of the tamping tool have a wear-resistant tip inserted into a groove in the end of the blade. The tamping tool of the present invention reduces wear, providing an increased life and increasing the time intervals at which it becomes necessary to replace the tamping tool.

TECHNICAL FIELD  
       [0001]     The invention relates to ballast tamping tools that are used on tamping machines for adjusting and leveling ballast under railway ties of railroad tracks.  
       BACKGROUND  
       [0002]     Railroad tracks are typically supported by cross ties, typically made of wood, that run the width of the tracks, and are attached thereto by spikes. The cross ties rest upon ballast, which typically consists of gravel, crushed rocks or the like. The ballast typically shifts over time, with movement. Ballast tamping tools, which are machines that run along the railroad tracks, are used to tamp the ballast back into place around the cross ties so that the cross ties and the tracks attached thereto are adequately supported.  
         [0003]     Ballast tamping tools have a reciprocating tamping drive, that move and vibrate shafts attached to the drive such that a pair of spaced-apart shafts, and the ballast blades, or paddles, attached to the other end of the shafts move towards and away from each other, tamping and compressing the ballast positioned under and around the cross ties. The ballast blades undergo a great deal of wear as a result of repeated contact with the ballast and edges of the cross ties, especially the face of the blade that is pressed against the ballast. When the blades wear out, chip, or snap off, they no longer perform the tamping task effectively, and must be replaced. To replace the shafts and/or attached blades necessitates shutting down the entire machine and removing the shaft(s) with worn or damaged blades. The necessity to shut down the equipment is obviously time-consuming, and reduces productive operating time for the equipment.  
         [0004]     Therefore, what is needed is a system and method for enhancing the life of the blade to extend the interval at which blades must be replaced or repaired. A variety of devices and enhancements have been developed to help prolong the life of the ballast tamping tool shaft blade, or to simplify replacement of the blade.  
         [0005]     For example, U.S. Pat. Nos. 3,581,664, 4,062,291 and 4,068,594 disclose tools in which the blade is secured to the end of the shaft with one or more screws so the blade can be easily removed when it has worn and needs to be repaired. However, in use, it was found that the vibrating motion of the tamping machine tended to loosen, or back out the screws such that the blades would detach from the shafts.  
         [0006]     U.S. Pat. No. 4,160,419 discloses a system where the blade is rectangular and is gradually tapered from one side to the other so that the blade can sustain a greater amount of wear. However, this mechanism is complex, and must be opposed with a blade that is tapered in the opposite direction, necessitating more work and keeping multiple parts in stock.  
         [0007]     U.S. Pat. No. 4,501,200 discloses a system that attaches the tamping blades to the shaft in a method that simplifies replacement of the blades, combined with blades having a hardened working face. However, this system requires replacement of the standard shaft with the special system of the patent.  
         [0008]     U.S. Pat. No. 5,261,763 discloses a tool in which bits of hardened material have been attached to the blade. However, the hardened material is configured such that it has a ledge at the lower end which underlies the lower end of the blade. The configuration is such that the ledge of the hardened material is prone to catching on the ballast, detaching the hardened material from the underlying blade during use.  
         [0009]     Thus, an on-going need exists for a tamping tool mechanism in which the necessity to replace the shaft blade is reduced or simplified.  
       SUMMARY  
       [0010]     The present invention, accordingly, provides a tamping tool of the general character described in U.S. Pat. No. 5,261,763 which overcomes these and other difficulties.  
         [0011]     In one embodiment of the present invention, a wedge-shaped tip with a rounded end made of wear-resistant material is inserted in the lower end of the blade, and wear-resistant material is placed along both faces of the of the blade to increase side wear. The shape of the tip transfers impact into the body of the blade, to increase life.  
         [0012]     In another embodiment of the present invention, pieces of wear-resistant material have been placed along the face of the blade, including a very thick piece at the top of the blade, where it adjoins the shaft, which improves the life of the blade. Additionally, large pieces of wear-resistant material with a rounded edge are attached at the tip of the blade, with additional wear-resistant material on the rear side of the blade to improve impact resistance and wear.  
         [0013]     In yet another embodiment of the present invention, a tip shaped like an opened parachute made of wear-resistant material is inserted in the lower end of the blade. This shape protects the end of the tip area and the pieces of wear-resistant material attached to the side of the blade. This shape provides extra protection such that if the wear-resistant material on the side of the blade and the blade body wear through, the portion of the parachute tip inserted up into the blade will be what comes in contact with the ballast, to provide additional life for the blade.  
         [0014]     In a further embodiment of the present invention, the arrangement of the tool has the shank slightly off-set from center, and has wear-resistant material on both faces of the blade so that one blade can be used in either position by rotating it 180 degrees in the tool shaft holder. When one face of the blade has worn, it can be rotated and swapped with a blade from the other side of the tamping tool for continued use.  
         [0015]     Although it is known that facing a tool with wear-resistant hardened material, such as tungsten carbide, can increase the life of the tool, the results seen with the arrangements of wear-resistant material of the present invention yielded an unexpected increase in wear life of 25 to 75 times the life of uncoated blades.  
         [0016]     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:  
         [0018]      FIG. 1  is a front elevation view of a first arrangement of a tamping tool blade of the present invention;  
         [0019]      FIG. 2  is an side view of the system of  FIG. 1  taken along the line  2 - 2  of  FIG. 1 ;  
         [0020]      FIG. 3  is a rear elevation view of a first arrangement of a tamping tool blade of the present invention;  
         [0021]      FIG. 4  is a front elevation view of a second arrangement of a tamping tool blade of the present invention;  
         [0022]      FIG. 5  is an side view of the system of  FIG. 4  taken along the line  5 - 5  of  FIG. 4 ;  
         [0023]      FIG. 6  is a rear elevation view of a second arrangement of a tamping tool blade of the present invention;  
         [0024]      FIG. 7  is a front elevation view of a third arrangement of a tamping tool blade of the present invention;  
         [0025]      FIG. 8  is an side view of the system of  FIG. 7  taken along the line  8 - 8  of  FIG. 7 ;  
         [0026]      FIG. 9  is a front elevation view of a fourth arrangement of a tamping tool blade of the present invention;  
         [0027]      FIG. 10  is an side view of the system of  FIG. 9  taken along the line  10 - 10  of  FIG. 9 ;  
         [0028]      FIG. 11  is a rear elevation view of a fourth arrangement of a tamping tool blade of the present invention;  
         [0029]      FIG. 12  is a front elevation view of a fifth arrangement of a tamping tool blade of the present invention, which is a variation of the fourth arrangement;  
         [0030]      FIG. 13  is an side view of the system of  FIG. 12  taken along the line  13 - 13  of  FIG. 12 ;  
         [0031]      FIG. 14  is a rear elevation view of a fifth arrangement of a tamping tool blade of the present invention; and  
         [0032]      FIG. 15  is a detailed view of the tip used in the arrangements of the present invention shown in  FIGS. 7-14 . 
     
    
     DETAILED DESCRIPTION  
       [0033]     In the discussion of the FIGURES the same reference numerals will be used throughout to refer to the same or similar components. In the interest of conciseness, various other components known to the art, such as tamping machines, rails, ties and spikes, have not been shown or discussed.  
         [0034]     Referring to  FIGS. 1, 2 , and  3  of the drawings, the reference numeral  10  generally designates a tamping tool of the present invention, which comprises a shank  11   a , and a blade  100  that is welded to the lower end of the shank  11   a , or is forged as a single unit with the shank  11   a . As can be clearly seen in  FIG. 3 , the end of the shank  11   a  at the blade  100  bulges out slightly before tapering down near the end of the blade  100 . This shape provides strength and structural integrity to the shank  11  and blade  100 .  
         [0035]     The body  102  of the blade  100  is typically formed of a metal, such as steel, iron or the like, but can be made of other materials as well. The blade  100  has a front face  104 , a rear face  106 , a top  108 , a tapered, or slanted bottom  110  and a bottom end  112 . Typically, the blade  100  is about 2-6 inches long, about 2-6 inches wide, and about ¾ inch thick at the top  108 , tapering to the bottom end  112 . The blade  100  has tiles  120  of a wear-resistant material, such as tungsten carbide or the like, secured to the faces  104 ,  106  of the blade  100  at the top  108  of the blade  100 . In some configurations of this arrangement of the present invention, wear-resistant tiles  122  are secured to the bottom portion of the shank  11   a  for longer wear. Each tile  120  is preferably about 0.125 inches thick for long wear. The blade also has one or more other tiles  130  of wear-resistant material secured to the faces  104 ,  106  of the blade  100  near the bottom  110 . Each tile  130  is preferably about 0.125 inches thick for long wear. The tiles  130  protect the slanted bottom  110  portion of the blade  100 . The bottom end  112  has a groove cut down into the blade  100 .  
         [0036]     A tip  140 , which is shaped like a parachute or an elongated tear, is inserted into the groove in the bottom end  112 , with the rounded tear projecting outward. The shape of the tip  140  is designed to absorb impact and transfer it into the body of the tool  10 . The tip  140  is made of a wear-resistant material, such as tungsten-carbide. Multiple smaller tips  140  of wear-resistant material having an elongated shape can also be inserted in the groove adjacent to each other to fill in the entire groove, rather than a single continuous tip  140 .  
         [0037]     One or more pins  150  are inserted into the body  102  near the top  108 . The pins  150 , are typically made of a wear-resistant material and run through the width of the body  102  to provide increased strength to the body  102 , which increases the life of the tiles  120 ,  122 ,  130  attached to the body  102 . The tiles  120 ,  122 ,  130 , tip  140 , and pins  150  are attached to the body  102  by means of brazing, soldering, gluing or other appropriate means.  
         [0038]     Referring to  FIGS. 4, 5 , and  6  of the drawings, a second embodiment of the present invention is shown, in which the reference numeral  12  generally designates a tamping tool of the present invention, which comprises a shank  11   b , and a blade  200  that is welded to the lower end of the shank  11   b , or is forged as a single unit with the shank  11   b . As can be clearly seen in  FIG. 6 , the end of the shank  11   b  at the blade  200  bulges out slightly before tapering down near the end of the blade  200 . This shape provides strength and structural integrity to the shank  11   b  and blade  200 . The shank  11   b  can be centered on the rear face  206  of the blade  200  as shown in  FIG. 6 , or it can be positioned to the left or right of center (not shown), depending on the arrangement of tamping equipment the tamping tool  12  will be used with.  
         [0039]     The body  202  of the blade  200  is typically formed of metal, such as iron or steel, but can be made of other materials as well. The blade  200  has a front face  204 , a rear face  206 , a top  208 , a slanted bottom  210  and a bottom end  212 . Typically, the blade  200  is about 2 to 6 inches long, about 2-6 inches tall, and about {fraction (3/4)} inches thick at the top  208 , tapering toward the bottom end  212 . The blade  200  has tiles  220  of a wear-resistant material secured to the front face  204  of the blade  200  at the extreme upper portion of the top  208  of the blade  200 . Each tile  220  is preferably about {fraction (3/8)} inches thick for long wear. The blade  200  also has another layer of wear-resistant tiles  230  secured to the front face  204  of the top  208  of the blade. Each tile  230  is preferably about 0.125 inches thick for long wear. In some configurations of this arrangement of the present invention, wear-resistant tiles  222  are secured to the bottom portion of the shank  11   b  for longer wear.  
         [0040]     The blade also has additional wear-resistant tiles  240  secured to the front face  204  of the bottom  210  of the blade. The tile  240  protects the slanted bottom  210  portion of the blade  200 . The tile  240  is rounded at the end near the bottom  212  of the blade to minimize edge wear at the part of the strip  240  that impacts down into the ballast, and eliminate edges that could catch in the ballast and be torn off of the blade  200 , as in the prior art. The tile  240  can be a single tile extending across the entire face of the blade, multiple smaller tiles  240  can be secured to the blade to cover the entire face of the blade.  
         [0041]     The blade  200  can also have another layer of wear-resistant tiles  250  secured to the rear face  206  of the bottom  210  of the blade. The tiles  250  protect the slanted rear bottom  210  portion of the blade  200 , which absorbs the impact when the blade  200  is compressing the ballast inwards. This portion of the blade  200  also comes in contact with the ballast when the blade  200  is being pulled back from compacting the ballast under the cross ties (not shown). The tiles  250  reduce the wear frequently seen on this portion of the blade  200 . Each tile  250  is preferably about 0.125 inches thick for long wear. The tiles  220 ,  230 ,  240  and  250  are attached to the body  102  by means of brazing, soldering, gluing or other appropriate means.  
         [0042]     Referring to  FIGS. 7 , and  8  of the drawings, the reference numeral  14  generally designates a tamping tool of the present invention, which comprises a shank  11   c , and a blade  300  that is welded to the lower end of the shank  11   c , or is forged as a single unit with the shank  11   c . This arrangement of the present invention is intended for use in tamping equipment that utilize tamping tools  14  configured with the shank  11   c  positioned to the left or right of center. Because this arrangement of the tool  14  in the present invention has wear-resistant material  320 ,  322  on both faces of the blade  300 , one tool  14  can be used in either position by rotating it 180 degrees in the tool shaft holder (not shown). This eliminates the need to keep multiple parts in stock. Additionally, when one face of the tamping tool  14  has worn, it can be rotated and swapped with a tamping tool  14  from the other side of the tamping equipment for continued use. This results in a life that is twice as long for this arrangement of tamping tool  14 .  
         [0043]     The body  302  of the blade  300  is typically formed of metal, such as iron or steel, but can be made of other materials as well. The blade  300  has a front face  304 , a rear face  306 , a top  308 , a bottom  310  and a bottom end  312 . Typically, the blade  300  is about 2 to 6 inches long, about 2-6 inches tall, and about {fraction (3/4)} inches thick at the top  308 , tapering toward the bottom end  312 . The bottom end  312  has a groove cut down into the blade body.  
         [0044]     The blade  300  has tiles  320  made of a wear-resistant material, such as tungsten-carbide, secured to the entire surface of the front and rear faces  304 ,  306  of the blade  300 . Each tile  320  is preferably about 0.125 inch thick for increased wear resistance. Additionally, wear-resistant tiles  322  are secured to the bottom portion of the shank  11   c  for longer wear.  
         [0045]     A tip  340 , which is shaped like a mushroom, or a “T” with a rounded top, made of a wear-resistant material, is inserted into the groove in the bottom end  312  of the blade  300 , with the rounded top projecting outward. The shape of the tip  340  is designed to absorb impact and transfer it into the body of the tool  14 . Multiple smaller tips  3140  of wear-resistant material can also be inserted in the groove adjacent to each other to fill in the entire groove, rather than a single continuous tip  340 .  FIG. 15  shows a detailed view of the tip  340  of this arrangement of the present invention.  
         [0046]     The tiles  320 ,  322 , and tip  340  are attached to the shank  11 , and body  302  by means of brazing, soldering, gluing or other appropriate means.  
         [0047]     Referring to  FIGS. 9, 10 , and  11  of the drawings, the reference numeral  16  generally designates a tamping tool of the present invention, which comprises a shank  11   d , and a blade  400  that is welded to the lower end of the shank  11   d , or is forged as a single unit with the shank  11   d.    
         [0048]     The body  402  of the blade  400  is typically formed of metal, such as iron or steel, but can be formed from other materials as well. The blade  400  has a front face  404 , a rear face  406 , a top  408 , a bottom  410  and a bottom end  412 . Typically, the blade  400  is about 2 to 6 inches long, about 2-6 inches tall, and about {fraction (3/4)} inches thick at the top  408 , tapering toward the bottom end  412 . The blade  400  has tiles  420  of a wear-resistant material, such as tungsten-carbide, secured to the front face  404  of the blade  400  at the top  408  of the blade  400 . Each tile  420  is preferably about 0.125 inch thick for increased wear resistance.  
         [0049]     The blade also has wear-resistant tiles  430  of hardened material secured to the front face  404  of the bottom  410  of the blade. The tile  430  protects the bottom  410  portion of the blade  400 . Each tile  430  is preferably about 0.125 inches thick for long wear.  
         [0050]     The bottom end  412  has a groove cut down into the blade  400 . A tip  340 , which is shaped like a mushroom or a “T” with a rounded top, made of a wear-resistant material is inserted into the groove in the bottom end  412 , with the rounded top projecting outward. Multiple smaller tips  340  of wear-resistant material can also be inserted in the groove adjacent to each other to fill in the entire groove, rather than a single continuous tip  340 . The shape of the tip  340  is designed to absorb impact and transfer it into the body of the tool  16 .  FIG. 15  shows a detailed view of the tip  340  of this arrangement of the present invention.  
         [0051]     The blade  400  can also have wear-resistant tile  450  secured to the rear face  406  of the bottom  410  of the blade. The tiles  450  protect the slanted rear bottom  410  portion of the blade  400 , which absorbs the impact when the blade  400  is compressing the ballast inwards. This portion of the blade  400  also comes in contact with the ballast when the blade  400  is being pulled back from compacting the ballast under the cross ties (not shown). The tile  450  reduces the wear frequently seen on this portion of the blade  400 . Each tile  450  is preferably about 0.125 inches thick for long wear. Additionally, wear-resistant tiles  422  can be secured to the bottom portion of the shank  11   d  for longer wear.  
         [0052]     One or more pins  480  made of a wear-resistant material are inserted into the blade body  402  near the top  408 . The pins  480  run through the width of the body  402  to provide increased strength to the body  402 , which increases the life of the tiles  420 ,  422 ,  430 , and  450  attached to the body  402 . The wear-resistant tiles  420 ,  422 ,  430 ,  450 , tip  340 , and pins  480  are attached to the blade body  402  by means of brazing, soldering, gluing or other appropriate means.  
         [0053]     The embodiment of  FIGS. 12, 13 , and  14  is similar to the embodiment of  FIGS. 9, 10 , and  11 . According to the embodiment of  FIGS. 12, 13 , and  14 , the bottom end  512  is configured to taper up to a point in the center, rather than being essentially flat across the bottom.  
         [0054]     Referring to  FIGS. 12, 13 , and  14  of the drawings, the reference numeral  18  generally designates a tamping tool of the present invention, which comprises a shank  11   e , and a blade  500  that is welded to the lower end of the shank  11   e , or is forged as a single unit with the shank  11   e.    
         [0055]     The body  502  of the blade  500  is typically formed of metal, such as steel or iron, but can be formed from other materials, as well. The blade  500  has a front face  504 , a rear face  506 , a top  508 , a bottom  510  and a bottom end  512 . Typically, the blade  500  is about 2 to 6 inches long, about 2-6 inches tall, and about {fraction (3/4)} inches thick at the top  508 , tapering toward the bottom end  512 . AS can be seen, the bottom end  512  of the blade  500  comes to a peak or apex in the center of the blade, and tapers downwards from the tip toward both edges. The blade  500  has wear-resistant tiles  520  of various sizes secured to the front face  504  of the blade  500  at the top  508  of the blade  500 . Each strip of wear-resistant material  520  is preferably about 0.125 inch thick for increased wear resistance.  
         [0056]     The bottom end  512  has a groove cut down into the blade  500 . A tip  340 , which is shaped like a mushroom or a “T” with a rounded top, is inserted into the groove in the bottom end  512 , with the rounded top projecting outward. Multiple smaller tips  340  of wear-resistant material can also be inserted in the groove adjacent to each other to fill in the entire groove, rather than a single continuous tip  340 . The shape of the tip  340  is designed to absorb impact and transfer it into the body of the tool  18 .  FIG. 15  shows a detailed view of the tip  340  of this arrangement of the present invention.  
         [0057]     The blade  500  also has another wear-resistant strip  550  secured to the rear face  506  of the bottom  510  of the blade. The strip  550  protects the slanted rear bottom  510  portion of the blade  500 , which absorbs the impact when the blade  500  is compressing the ballast inwards. This portion of the blade  500  also comes in contact with the ballast when the blade  500  is being pulled back from compacting the ballast under the cross ties (not shown). The wear-resistant strip  550  reduces the wear frequently seen on this portion of the blade  500 . Each wear-resistant strip  550  is preferably about 0.125 inches thick for long wear. Additionally, wear-resistant tiles  522  are secured to the bottom portion of the shank  11   e  for longer wear.  
         [0058]     One or more pins made of a wear-resistant material  580  are inserted into the blade body  502  near the top  508 . The pins  580  run through the width of the body  502  to provide increased strength to the body  502 , which increases the life of the tiles  520 ,  522 , and  550  attached to the body  502 . The tiles  520 ,  522 ,  550 , tip  340 , and pins  580  are attached to the blade body  502  by means of brazing, soldering, gluing or other appropriate means.  
         [0059]      FIG. 15  shows a detailed view of the tip  340  used in the embodiments of the present invention shown in  FIGS. 7-14 . As can be seen, the tip  340  is shaped like a mushroom, with a rounded top, and a leg that is tapered inward from the top to a flat bottom.  
         [0060]     In addition to the advantages described above with respect to the previous embodiment, the alternate embodiment. It is understood that the present invention can take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention.  
         [0061]     Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.