Patent Publication Number: US-9416509-B2

Title: Machine group and method for cleaning ballast of a track

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a machine group for cleaning ballast of a track which comprises a first machine, having an endless clearing chain for picking up the ballast located underneath the track and a first screening plant for a ballast cleaning, a second machine preceding the former with regard to a working direction and having a pick-up device for picking up cleaned ballast pre-deposited on the track, and a first conveyor belt arrangement for passing the cleaned ballast from the pick-up device on to a discharge point, situated rearward of the clearing chain, of the first machine. The invention also relates to a method for cleaning ballast of a track, wherein cleaned ballast pre-deposited on the same is picked up, transported to an intermediate store and discharged, as needed, rearward of a clearing chain of a machine designed for cleaning. 
     A machine group of this type is known from U.S. Pat. No. 5,513,452 and is composed of a cleaning machine and a machine preceding the same which has a pick-up device for picking up cleaned ballast pre-deposited on the track. Provided between the two machines is a storage wagon having bottom conveyor belts which are part of a conveyor belt arrangement extending from the said pick-up device to a discharge point of the cleaning machine. In this manner, it is possible to use the pre-deposited ballast for replenishing the ballast cleaned by the cleaning machine, as needed. 
     According to U.S. Pat. No. 5,090,484, it is also known to arrange a shoulder cleaning machine so as to precede a cleaning machine having an endless clearing chain. Positioned immediately ahead of the clearing chain is a device for picking up ballast pre-deposited on the track, in order to discharge said ballast upon the track immediately to the rear of the clearing chain. This, however, has the disadvantage that an adjustment to adapt to the current ballast demand is not possible. 
     BRIEF SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide a machine group and a method of the type mentioned at the beginning with better higher work performance as well as improved ballast distribution can be accomplished. 
     According to the invention, this object is achieved with a machine group or a method of the type mentioned at the beginning by way of the inventive features as claimed. 
     Such a combination of features enables a parallel transfer of the ballast cleaned by the third machine, together with the ballast picked-up from the track by the second machine, to the discharge point of the first machine. Furthermore, any desired number of storage wagons, each having a bottom conveyor belt, can be incorporated without problems into this ballast transport without thereby negatively affecting the transport performance. Thus, in an advantageous way, the ballast picked up by both the third machine as well as the second machine can be intermediately stored and passed on, as needed. 
     Additional advantages of the invention become apparent from the drawing description. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The invention will be described in more detail below with reference to embodiments represented in the drawing in which  FIGS. 1 and 2  show a first variant and  FIGS. 3 to 7  show a second variant of a machine group for cleaning ballast of a track. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     A machine group  1 , shown in  FIGS. 1 and 2 , is composed of a first machine  2 , configured as a cleaning machine, a second machine  4  preceding the same with regard to a working direction  3 , and—preceding the latter—a third machine  6  equipped with shoulder excavating devices  5 . The said machines  2 ,  4 ,  6  are connected to one another by couplings  7  and mobile on a track  8 . 
     The first machine  2  has an endless clearing chain  9 , guided around the track  8 , and a first screening plant  10  which can be charged by the chain  9 . Immediately to the rear of the clearing chain  9 , a discharge point  11  for discharging the cleaned ballast upon the track  8  is provided. 
     The second machine  4 , comprising a two-part machine frame  19 , is equipped with a pick-up device  12  for picking-up cleaned ballast  13  pre-deposited on the track  8 . A first conveyor belt arrangement  14  is provided for transferring the cleaned ballast  13  from the pick-up device  12  on to the discharge point  11 , situated rearward of the clearing chain  9 , of the first machine  2 . 
     The third machine  6  has a second screening plant  15  for cleaning the ballast picked up by the shoulder excavating devices  5  from a shoulder region of a ballast bed. Provided for further transport of the ballast cleaned in the second screening plant  15  is a second conveyor belt arrangement  16 . To that end, the latter has a receiving end  17 , positioned underneath the second screening plant  15 , and a discharge end  18  situated above the first conveyor belt arrangement  14 . 
     The operating mode of the machine group  1 , mobile continuously on the track  8  during working operations, and the method for cleaning ballast will now be described in more detail. The two shoulder excavating devices continuously pick up the ballast located in the shoulder region of the ballast bed, said ballast being cleaned in the second screening plant  15 . 
     By means of the pick-up device  12 , the second machine  4  picks up cleaned ballast pre-deposited on the track  8  and transports the same via the first conveyor belt arrangement  14  past the clearing chain  9  to the discharge point  11 . Said first conveyor belt arrangement  14  also serves for transporting the cleaned ballast, coming from the second screening plant  15 , on to the said discharge point  11 . 
     By means of the first machine  2 , the rest of the ballast still remaining under the track  8  is picked up, cleaned in the first screening plant  10 , and also discharged via the discharge point  11  upon the track  8 . 
     In the case of the alternative of a machine group  1  shown in  FIGS. 3 to 7 , machine parts already described with reference to  FIGS. 1 and 2  and having the same function are denoted by the same reference numerals for the sake of simplicity. The essential difference lies in the fact that intermediate stores  23  in the shape of special storage wagons  20  are arranged between the first and second machine  2 ,  4 . These intermediate stores  23  each have a bottom conveyor belt  21  and a transfer conveyor belt  22 , both forming a section of the first conveyor belt arrangement  14 . Owing to these storage wagons  20 , there is the possibility of storing both the ballast picked up from the track  8  by means of the second machine  4  as well as the ballast coming from the second screening plant  15 . By varying the speed of the conveyor belts  21 ,  22 , the stored ballast can be transported onward to the discharge point  11  as needed and in the required amounts. 
     Additional storage wagons  20  are positioned following or preceding the first and third machine  2 ,  6  in order to store the spoil accruing in the screening plants  10 ,  15 , respectively.