Patent Publication Number: US-6209462-B1

Title: Machine with ballast scarifying device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a machine comprising a machine frame supported on undercarriages adapted to support the machine frame on a track comprised of rails fastened to ties defining cribs therebetween, and a ballast scarifying device for removing ballast from a respective one of the cribs between the rails. 
     2. Description of the Prior Art 
     U.S. Pat. No. 5,125,345 discloses a tie exchange machine in which a ballast scarifying device is arranged to remove ballast from a crib adjacent the tie to be exchanged. The ballast scarifying device is comprised of four ballast clearing plates spaced from each other in a direction extending transversely to the machine frame. Pairs of the ballast clearing plates may be independently displaced in a transverse direction towards a respective one of the track shoulders. This transverse displacement will remove the ballast from the crib towards the track shoulders. 
     French patent No. 2,588,023 and German patent No. 1,116,257 disclose machines with endless bucket chains for clearing ballast from a track bed. The bucket chain is lowered into the ballast between the track rails to excavate the ballast and convey it upwards to a conveyor band. Before the bucket chain is immersed in the ballast, the track ties must be removed. 
     U.S. Pat. No. 4,611,541 discloses a ballast cleaning machine in which an endless ballast excavating chain is mounted between two tie exchange devices to remove the entire ballast of the track bed and to convey it to a cleaning screen. 
     U.S. Pat. No. 5,513,452 also deals with an installation for the rehabilitation of a ballast bed. A first ballast excavating device is arranged at the front of the installation for receiving clean ballast deposited on the track, and this clean ballast is conveyed behind a second ballast excavating device which clears the dirty ballast to expose the subgrade. The dirty ballast is cleaned and returned to the exposed subgrade where the clean ballast conveyed from the first ballast excavating device is used to supplement the cleaned ballast. 
     SUMMARY OF THE INVENTION 
     It is the primary object of this invention to improve a machine of the first described type so that a tie exchange operation may be facilitated with a better ballast scarifying device. 
     In such a machine, this object is accomplished according to the invention with a ballast scarifying device comprising a revolvable endless excavating chain vertically adjustably mounted on the machine frame for removing ballast from a respective one of the cribs between the rails, a drive for revolving the endless excavating chain, and a displacement drive for vertically adjusting the endless excavating chain. The endless excavating chain has a lowermost ballast receiving part being immersible in ballast in the crib between the rails upon vertical adjustment of the endless excavating chain. 
     Such an excavating chain makes it possible to clear substantially all the ballast in the crib between the rails. Moreover, it has the advantage to enable the cleared ballast to be completely removed from the track by the chain for immediate storage. Therefore, a new tie may be readily inserted without any obstacles in its way, and the full tie inserting movement under the second rail in the inserting direction is not hindered by jammed ballast. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The above and other objects, advantages and features of the present invention will become more apparent from the following detailed description of a now preferred embodiment thereof, taken in conjunction with the accompanying drawing wherein 
     FIG. 1 is a side elevational view of a machine according to this invention; and 
     FIG. 2 is an enlarged fragmentary end view of the ballast scarifying device, taken in the direction of arrow II of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     As shown in FIG. 1, machine  1  for clearing ballast from a crib comprises machine frame  5  supported on undercarriages  4 ,  4  adapted to support the machine frame on track  3  comprised of rails  16  fastened to ties  44  defining cribs  2  therebetween. Cab  7  is mounted on a front end of the machine frame, in the operating direction indicated by arrow  6 , and central control  8  is arranged in the cab, which also holds power plant  10  for the various drives of the machine to be described hereinafter, including drive  9  for moving machine  1  along track  3 . 
     Ballast scarifying device  11  is mounted on machine frame  5  between undercarriages  4 ,  4 . The ballast scarifying device comprises revolvable endless excavating chain  12  for removing ballast from a respective one of cribs  2  between rails  16 , and ballast clearing plate  13 . Endless excavating chain  12  is vertically adjustably mounted on machine frame  5  and comprises drive  14  for revolving the endless excavating chain. The endless excavating chain has a lowermost ballast receiving part  15  facing track  3  and immersible in ballast in crib  2  between rails  16  upon vertical adjustment of endless excavating chain  12 . For this purpose, displacement drive  18  for vertically adjusting the endless excavating chain is mounted in telescopingly extensible carrier arm  17  affixed to machine frame  5 . 
     Points of contact  19  between track rails  16  and wheels on undercarriages  4 ,  4  define running plane  20  extending in a longitudinal direction along track  3 , and endless excavating chain  12  is arranged to revolve and to be vertically adjusted in plane  21  extending transversely to the longitudinal direction and at an acute angle α to the running plane. The angle is preferably between 40° and 50°. 
     In the illustrated embodiment, the ballast scarifying device further comprises flanged rollers  22  transversely spaced from each other and supporting endless excavating chain  12  on track rails  16 . The flanged rollers are adjustably positionable in plane  21  in which the endless excavating chain is arranged, for which purpose they are connected to vertical adjustment drive  23  connecting flanged rollers  22  to endless excavating chain  12 . Furthermore, transversely spaced support rollers  24  affixed to machine frame  5  are arranged for additional support and guidance of endless excavating chain  12 . Support rollers  24  are freely rotatable about horizontal axis  25  extending in a transverse direction. 
     As endless excavating chain  12  is revolved, it conveys the ballast scooped up by lowermost ballast receiving part  15  to opposite end  26  of the endless excavating chain, where the ballast is discharged into opening  27  of a ballast storage bin  28  mounted on machine frame  5 . The bottom of the storage bin is constituted by conveyor band  29  extending in the longitudinal direction of the machine frame, and this conveyor band has a discharge end  30  above discharge chutes  31  so that the excavated ballast may be returned to the track bed. 
     As best shown in FIG. 2, ballast scarifying device  11  further comprises ballast clearing plate  13  arranged in vertical plane  32  extending in a longitudinal direction along track  3  and positioned in track shoulder  33 . Ballast cleaning plate  13  is affixed to tool carrier  34  mounted on vertically and transversely extending guides  35 ,  36 . Drives  37 ,  38  are connected to tool carrier  34  for independently displacing the ballast clearing plate in a vertical and transverse direction. 
     The specific construction of revolvable endless ballast excavating chain  12  is generally the same as in conventional ballast cleaning machines widely used in track maintenance and rehabilition, and it has been schematically illustrated at lowermost ballast receiving part  15 . The chain is comprised of a multiplicity of chain links  40  and, outside the lowermost ballast receiving part, it runs in trough-shaped guide members  39  carried on machine frame  5  by rollers  24  and carrier arm  17 . Each chain link  40  carries scraping fingers  41  which engage the ballast in crib  2  and remove it from the crib as the chain revolves. This removed ballast is then conveyed in an upwardly extending trough-shaped guide member  39  to discharge end  26 , and the revolving chain returns empty in a downwardly extending trough-shaped guide member. 
     Machine  1  is operated in the following manner: 
     The machine is driven in the operating direction indicated by arrow  6  to the site of crib  2  to be cleared of ballast after an adjacent tie has been removed in a manner not further described or illustrated. To clear the ballast from shoulder  33  adjacent crib  2 , drive  37  is actuated to lower ballast clearing plate  13  until it is immersed in shoulder ballast  42  immediately adjacent rail  16  of track  3 , as shown in phantom lines in FIG.  2 . Drive  38  is then actuated to displace clearing plate  13  transversely outwardly to remove the ballast from shoulder region  33  to shoulder embankment  43 . Crib ballast between track rails  16  is then cleared by actuating displacement drive  18  to displace endless balance excavating chain  12  from a raised transit position, shown in phantom lines in FIG. 1, to an operating position, shown in full lines, in which lowermost chain part  15  is immersed in ballast in crib  2  between rails  16 . At the same time, drive  14  is actuated to revolve the endless ballast excavating chain in the direction indicated by small arrows in FIG. 2 so that the lowermost chain part may clear the ballast in the crib. By actuating drives  23  to adjust the vertical distance of flanged rollers  22  from the endless ballast excavating chain, the depth of immersion of lowermost excavating chain part  15  in the ballast may be controlled. The ballast removed from crib  22  is discharged from end  26  into intermediate storage bin  28 . Bottom conveyor band  29  is driven so that the ballast may be discharged to the track bed from the storage bin at selected sites through discharge chutes  31 . 
     To enable the cribs to be cleared accurately of ballast, machine  1  is advanced just a little in the operating direction, i.e. just before tie  44  adjacent to cleared crib  2 . By displacing ballast excavating chain  12  into the raised transit position, machine  1  may be advanced to the next crib to be cleared. All the operating drives of the machine are actuated by control  8  in operator&#39;s cab  7 . The subsequent insertion of new ties in cleared cribs  2  is effected by a tie exchange machine, independently of the operation of machine  1 . 
     If desired, the illustrated embodiment of machine  1  may also carry devices for pulling and inserting ties, as well as devices for conveying and storing old and new ties. 
     Also, the flexbility of machine  1  may be enhanced if a further ballast clearing plate similar to that of ballast clearing plate  13  were installed at the opposite side of machine frame  5 .