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BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus and method for scarifying a railway tie bed, thereby providing sufficient space within the ballast for insertion of a replacement railway tie. More specifically, the present invention includes a scarifier capable of being mounted on a tie insertion/removal vehicle. 
     2. Description of the Related Art 
     Scarifying is a step in the process of removing and replacing old railway ties, wherein some of the ballast immediately surrounding the space formerly occupied by the old tie is removed, thereby providing additional space for insertion of the new tie. Although the present trend is to minimize the frequency with which this step is performed, scarifying is still helpful in locations wherein the ballast has been compacted and/or contaminated, resulting in excessive difficulty in inserting the new tie. 
     One proposed system of displacing ballast includes a pointed plow having a plurality of lateral ejectors, with each ejector reciprocating between a first position wherein one end of the ejector protrudes from the plow, and the opposite end is retracted, and a second position wherein the previously retracted end of the ejector is now extended, and the first end of the ejector is retracted within the plow. The lateral ejectors may be actuated in pairs, so that when one ejector is moved towards one side of the plow, a corresponding ejector is moved towards the opposite side of the plow. 
     Another proposed scarifying device includes horizontally and vertically reciprocating ballast clearing elements. The ballast clearing elements are moved vertically by a vertical displacement drive and vertical displacement guides. The ballast clearing elements and associated carrier are moved horizontally as a unit. The ballast clearing elements are pivotally secured to the carrier at their top ends, permitting them to pivot upward and outward. 
     Yet another proposed scarifying device includes a rotating drum having a plurality of pivotally attached hammer arms. Each hammer arm includes tool at its end for removing ballast, and a tie protecting portion on its front surface. As the drum rotates, the hammer arms are pulled outward by centrifugal force, causing the tooth of the hammer to strike the ballast, thereby removing the ballast from the desired location. When the rotating drum passes over a tie, the tie protecting portion of the hammer will strike the tie before the tooth, causing the hammer to be deflected towards the drum, preventing the tooth from damaging the tie. 
     Lastly, another scarifying apparatus includes three digging plates, with one digging plate extending between the tracks, and the other two digging plates each located on one side of the tracks. 
     The majority of the presently proposed scarifying devices are therefore designed to remove significantly greater amounts of ballast than the small amount necessary to widen the channel within the ballast previously occupied by the old tie, thereby permitting insertion of a new railway tie. Additionally, presently available scarifying devices are not particularly suited to mounting on a tie inserting/removal machine. 
     Accordingly, a scarifying device adapted for mounting on a tie remover/inserter machine is desired. Additionally, a scarifier having laterally reciprocating tines for removing ballast only immediately adjacent to the space occupied by an old railway tie is desired. 
     SUMMARY OF THE INVENTION 
     The present invention is a railway tie bed scarifier capable of being mounted on a tie remover/inserter machine, and being adapted to remove only that ballast immediately around the space wherein an old tie was formerly located. 
     The tie bed scarifier includes a plurality of tines, with a preferred number being four, supported by a carriage. The carriage is adapted to be raised into a travel position, and lowered into a work position. In the travel position, the tines are sufficiently raised to clear the railway tracks. In the work position, the tines are positioned slightly below the rails. The tines are mounted on the carriage so that they may reciprocate back and forth within the space to be occupied by a tie, perpendicular to the rails. A preferred configuration of tines includes four tines, with two adapted to travel towards one rail, and the other two adapted to travel towards the other rail. Preferably, the two tines adapted to travel in one direction will be located at opposing sides of the channel within the ballast. 
     In use, the scarifier will be in its raised travel position until needed. When the scarifier is needed, the tie remover/inserter machine will be moved so that the scarifier is directly over the channel in the ballast wherein an old tie was formerly located. The carriage will be lowered from the travel position to the work position, with the tines kept in their retracted position so that they pass between the tracks. Once the carriage is in the work position, the tines are extended and retracted within the channel left by the removed tie, thereby widening the channel. Once the channel within the ballast has been sufficiently widened, the tines are retracted, the carriage is raised to its travel position, and the tie remover/inserter machine travels sufficiently so that the tie removal/insertion arm is adjacent to the channel. 
     It is therefore an aspect of the present invention to provide a railway tie bed scarifier capable of being mounted on a tie remover/inserter machine. 
     It is another aspect of the present invention to provide a tie bed scarifier specifically adapted to widen pre-existing channels left within the ballast by the removal of old ties. 
     It is a further aspect of the present invention to provide a tie bed scarifier having a simplified design with respect to presently available scarifiers 
     It is another aspect of the present invention to provide an improved tie insertion method. 
     These and other aspects of the invention will become apparent through the following description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a tie remover/inserter machine with which the railway tie bed scarifier of the present invention will be used. 
     FIG. 2 is a side view of a railway tie bed scarifier according to the present invention, showing the carriage in its raised travel position. 
     FIG. 3 is a front view of a tie bed scarifier according to the present invention, showing the carriage in its raised travel position. 
     FIG. 4 is a side view of a tie bed scarifier according to the present invention, showing the carriage in its lowered work position. 
     FIG. 5 is a front view of a tie bed scarifier according to the present invention, showing the carriage in its work position and the tines in their retracted position. 
     FIG. 6 is a front view of a tie bed scarifier according to the present invention, showing the carriage in its work position and the tines in their extended position. 
     Like reference numbers denote like elements throughout the drawings. 
    
    
     DETAILED DESCRIPTION 
     The present invention is a railway tie bed scarifier for enlarging a channel within a railway track&#39;s ballast to facilitate insertion of a tie, and an associated method of inserting a tie. The scarifier of the present invention has the advantage of being mountable on a tie insertion/removal machine. The scarifier is bet understood through a brief description of a tie insertion vehicle and process. 
     FIG. 1 illustrates a railway tie insertion vehicle  10 . The tie insertion vehicle  10  includes an engine  12  for moving the vehicle  10  and supplying power to its various components, a plurality of wheels  14  for moving the vehicle  10  along the tracks  16 , and an operator&#39;s cab  18  from which the vehicle  10  and its various components are controlled. The engine  12  supplies power for operation of the hydraulic power system utilized to operate the various components of the vehicle  10 , with the hydraulic power system including a hydraulic fluid storage cylinder  20 , operatively connected with a plurality of valves  22  for channeling the hydraulic fluid to the various components of the vehicle  10 . 
     The vehicle  10  includes a pair of rail clamps  24 , dimensioned and configured to lift the rails  26  of the tracks  16  sufficiently to permit insertion and removal of the ties  28  beneath the rails  26  and tie plates  29 , supporting the rails  26  on the ties  28 . The rail clamp  24  includes a plurality of rollers  30  at the bottom end of a pair of scissor arms  31 , dimensioned and configured to grab the rail  26  from both sides beneath the rail&#39;s ball  32  (best illustrated in FIGS.  3  and  5 ). In use, the rollers  30  will be placed on either side of the rails  26 , beneath the ball  32 , and the rail clamp  24  will be raised, causing the scissor arms  31  to tighten around the rail  26 , and enabling the rail clamp  24  to deflect the rail  26  upward, typically approximately 1-2 inches. The rollers  30  permit the rail clamp  24  to remain clamped to the rail  26 , raising the rail  26  upward, as the vehicle  10  moves forward from tie  28  to tie  28  along the track  16 . 
     A tie kicker  34  is located near the rail clamp  24 . The tie kicker  34  includes an arm  36  having a striking plate  38  at one end, which is pivotally secured to the vehicle  10  at its other end  40 . In use, the arm  36  will pivot around the point  40  so that the striking plate  38  strikes a tie  28 , thereby pushing the tie  28  partially out from underneath the rails  26  and out from the ballast surrounding the tie  28 . The tie kicker  34  is used in conjunction with the tie boom  42  to remove old ties. 
     The tie boom  42  includes multiple telescoping sections, and terminates in a tie clamp  44 , dimensioned and configured to grasp a tie  28 . An example number of telescoping sections for the tie boom  42  is three, with these three sections extending horizontally, substantially parallel to the ties  28 . The tie clamp  44  is dimensioned and configured to be raised and lowered between a raised travel position and a lowered position wherein a tie  28  may be grasped. The tie boom  42  may be used to either insert new ties, or to remove old ties. To remove an old tie, the tie boom  42  is extended so that the tie clamp  44  is positioned above a portion of the tie  28  that may easily be grasped, the tie clamp  44  is lowered and closed around the tie  28 , and the tie boom  42  is then extended outward to slide the old tie  28  out from underneath the rails  26 , in a direction substantially parallel to the rail  28 . The old tie  28  may then be released by the tie clamp  44 , and left along side the track for later disposal. To insert a new tie, the tie boom  42  is first extended outward to a position wherein the tie clamp  44  is substantially directly above a new tie  28 , previously deposited along side the track  16 . The tie clamp  44  is lowered to a position wherein it may grasp the tie  28 . After the tie  28  is grasped, the tie clamp  44  is raised to a position wherein the tie  28  is aligned with a channel in the ballast surround the ties that has been left by removal of the previous tie, and the tie boom  42  is retracted to insert the new tie  28  underneath the tracks  26 . 
     The vehicle  10  also may include a ballast plow  46 , which may be lowered onto the tops of the ties  28  for removing ballast displaced during the tie insertion process, and/or a tie broom  48 , which may include a suction apparatus  50 , also for removing displaced ballast from the rails  26  and ties  28 . 
     Prior railway tie replacement processes frequently included the step of scarifying the channel left in the ballast after removal of the old tie, thereby widening and deepening the channel for ease of inserting the new tie into the channel. Presently used tie replacement methods generally do not use the scarifying step, but this step still remains beneficial in locations where the ballast has either been compacted or contaminated, for example, at road crossings, bridges, and switches, resulting in excessive difficulty in inserting the new tie. Because the scarifying step is used only for a limited number of occasions, having a dedicated scarifying machine is no longer advantageous. Therefore, the present invention provides a scarifier capable of being mounted on a typical tie removal/insertion machine  10 . 
     Referring to FIGS. 2-6, a scarifier  52  of the present invention includes a carriage  54  at one end of a positioning arm  56 . The carriage  54  includes at least two scarifying tines  58 ,  60 , with one scarifying tine  58  dimensioned and configured to remove ballast while moving towards one of the rails  26 , and the other scarifying tine  60  being dimensioned and configured to remove ballast when moved in the direction of the opposite rail  26 . The illustrated example includes four scarifying tines  58 ,  60 , with two tines  58  being dimensioned and configured to remove ballast in the direction towards one rail  26 , and the other two tines  60  being dimensioned and configured to remove ballast when moving towards the opposite rail  26 . The scarifying tines  58 ,  60  each correspond to one-half of one side of the channel within the ballast for containing a tie  28 . The carriage  54  also includes means for moving the scarifying tines  58 ,  60  between a retracted position wherein the carriage  54  may be raised and lowered between the rails  26  without interference between the tines  58 ,  60  and the rails  26 , and an extended position wherein the scarifying tines  58 ,  60  extend beneath the rails  26 . In the illustrated example, the means for moving the scarifying tines  58 ,  60  between their extended and retracted positions are the hydraulic cylinders  62 ,  64 , with the hydraulic cylinder  62  being dimensioned and configured to move the tines  58 , and the hydraulic cylinder  64  being dimensioned and configured to move the tines  60 . 
     The carriage  54  may include means for adjusting the height of the scarifying tines  58 ,  60  with respect to the carriage  54 . In the illustrated example, the carriage includes a pair of shim holders  66 , dimensioned and configured to contain a plurality of removable shims  68 , with the shims  68  secured in place by a pin  70 . By inserting and removing some of the shims  68  between the carriage  54  and the top surface  72  of the tine assembly  74  (including the tines  58 ,  60 , and hydraulic cylinders  62 ,  64 ), the height of the tine assembly  74  with respect to the carriage  54  may be adjusted, so that for a given height of rail  26 , when the bottom of the shim holders  66  rests on the ball  32  of the rails  26 , the scarifying tines  58 ,  60  will be located directly underneath the tie plates  29  of the rails  26 . Other alternative means of adjusting the height of the scarifying tines  58 ,  60  with respect to the carriage  54  may be used, with examples including threaded rods or electronically positioned hydraulic cylinders. 
     The positioning arm  56  is dimensioned and configured to guide the movement of the carriage  54  between a raised, travel position (FIGS.  2 - 3 ), and a lowered, working position (FIGS.  4 - 6 ). This may be accomplished by a positioning arm  56  having four elongated, substantially parallel members, pivotally secured to the carriage  54  at one end and to the tie insertion/removal vehicle  10  at the opposite end. Two of the four arm members, in the illustrated example, the bottom two members, will be support members  76  having a fixed length. The arm  56  preferably also includes a pair of guide members  78 , in the present example, the top two members of the arm  56 . The guide members  78  preferably have an adjustable length. The use of the fixed length support members  76  and adjustable length guide members  78  permits the carriage  54  to remain substantially horizontal whether in its raised position, lowered position, or anywhere in between. 
     The scarifier also includes means for raising and lowering the carriage  54 , which in the present example are at least two hydraulic cylinders  80 ,  82 . At least one hydraulic cylinder  80 , in the illustrated example, two hydraulic cylinders  80 , are pivotally secured between the tie insertion vehicle  10  and the arm  56  at  84 . Likewise, at least one hydraulic cylinder  82  is pivotally secured between the tie insertion vehicle  10  and the carriage  54  at the carriage&#39;s side  86 , opposite the arm  56 . In the illustrated example, two hydraulic cylinders  82  are used. 
     In use, the carriage  54  will remain in its raised position (FIGS. 2-3) until it is desired to scarify a channel within the ballast to facilitate insertion of a new tie  28 . The carriage  54  will be lowered from its raised position to its lowered position (FIGS.  4 - 5 ), wherein the scarifying tines  58 ,  60  contact the ballast where the location of the new tie  28  is desired. The tines  58 ,  60  are then repeatedly extended and retracted (FIGS. 5-6) between the rails  26  and tie plates  29 , as the hydraulic cylinders  80 ,  82  continue to push downward on the arm  56  and carriage  54 , until a channel of sufficient size for easy insertion of a new tie  28  has been formed. The tines  58 ,  60  are then moved to their retracted position (FIG.  5 ), so that the carriage  54  may be raised back up into its travel position (FIGS.  2 - 3 ). 
     While a specific embodiment of the invention has 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. Accordingly, the particular arrangements disclosed 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.

Summary:
A railway tie bed scarifier mounts on a tie remover/inserter machine. The tie bed scarifier is dimensioned and configured to widen the pre-existing channels left in the ballast through the removal of old ties. The tie bed scarifier includes a carriage moving between a raised travel position and a lowered work position, and a pair of tines reciprocating between a retracted position wherein they fit between the rails, and an extended position wherein they extend towards the sides of the ballast. A method of inserting a railway tie is also provided.