Patent Publication Number: US-2006000382-A1

Title: Spike pulling machine

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates, in general, to a spike pulling machine for pulling rail spikes from ties of a railroad track.  
      2. Description of Related Art  
      European published patent application No. 1 041 202 A1 describes a machine of the generic type. There, the machine has pincer-like gripping elements for engaging a head of a rail spike. In operation, these gripping elements are pulled upwards into a cylinder-shaped tube, which causes the gripping elements to be moved towards one another automatically for the purpose of gripping a spike head. However, this has the disadvantage that deformed spike heads, or spikes of different design, can not be gripped properly or can only be gripped with difficulty.  
     SUMMARY OF THE INVENTION  
      It is an object of the present invention to provide a spike pulling machine that overcomes the disadvantages of the heretofore-known machines of this general type, and with which it is possible without problems to also remove rail spikes even when they possess heads of varying design.  
      With the foregoing and other objects in view there is provided, in accordance with the present invention, a spike pulling machine for pulling rail spikes from ties of a railroad track extending in a track plane, the rail spikes having spike heads. The novel machine comprises a clamping device including gripping elements configured for application to a spike head; a clamping drive provided for moving the gripping elements relative to one another; and a vertical adjustment drive provided for adjusting the clamping device in a vertical direction.  
      With a solution of this kind, incorporating two separate drives, it is possible to ensure that the gripping elements of the clamping device are moved with a uniform and constant clamping force, independently of the width of the spike head to be gripped. Thus, any type of spike head can be most reliably engaged.  
      In accordance with an added feature of the invention, the machine further comprises a supporting leg intended for placement upon a tie of the track. The clamping device, together with the clamping drive, is mounted for vertical adjustment on said supporting leg.  
      In accordance with another feature of the invention, the machine further comprises flanged rollers, provided for support on the track and spaced from one another in a longitudinal direction, and operating handles for controlling the machine. The clamping device and the supporting leg are arranged one following the other with respect to the longitudinal direction, and the supporting leg is distanced from the operating handles farther than the clamping device.  
      In accordance with an additional feature of the invention, the machine further comprises a machine frame, mobile on the track by means of said flanged rollers, and a tool carrier supported on said machine frame for pivoting about an axis extending perpendicularly to the track plane, the clamping device and the supporting leg being mounted on said tool carrier.  
      In accordance with again an added feature of the invention, the tool carrier is fixable in its pivoted position relative to the machine frame by means of a blocking device.  
      In accordance with yet another feature of the invention, the supporting leg has a lower end configured as a supporting plate which is mounted for displacement relative to the supporting leg in a direction of longitudinal extension of the supporting leg and designed to be connected to the supporting leg in different displacement positions, as desired.  
      Other features which are considered as characteristic for the invention are set forth in the appended claims.  
      Although the invention is illustrated and described herein as embodied in a spike pulling machine for pulling railroad spikes, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.  
      The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of the specific embodiment when read in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side elevational view of a spike pulling machine; and  
       FIG. 2  is an enlarged partial side view of a clamping device according to the invention configured for engaging a spike head. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT  
      Referring now to the figures of the drawing in detail and first, particularly, to  FIG. 1  thereof, there is shown a side view of a spike pulling machine  1  including a machine frame  4 . The latter is mounted on a chassis frame  11  having flanged rollers  2 , provided for mobility of the machine  1  on a track  3  extending in a track plane  14 . The flanged rollers  3  are spaced from one another in a longitudinal direction of the machine, as indicated by arrow  31 . The machine frame  4  is supported on the chassis frame  11  by means of a carriage  10  which is articulatedly connected to the machine frame  4  for pivoting about an axis  9  extending transversely to the longitudinal direction. The carriage  10 , in turn, is mounted on the chassis frame  5  for displacement transversely to the longitudinal direction. The machine frame  4  is further equipped with a motor  5  and a hydraulic installation  6 . Operating handles  7  including control devices  8  are provided at an end of the machine frame  4  distanced from the motor  5 .  
      Situated between the carriage  10  and the operating handles  7  is a tool carrier  12  which is fastened to the machine frame  4  for pivoting about an axis  13 . The latter extends perpendicularly to the track plane  14 . A blocking device  19  is provided for arresting the pivoting movement of the tool carrier  12  about the axis  13 .  
      As shown also in  FIG. 2 , a supporting leg  15  extending perpendicularly to the track plane  14  is fastened to the tool carrier  12 . The supporting leg  15  has a lower end  16  connected to a supporting plate  18  which is provided for being placed upon a tie  17  of the track  3 . The supporting plate  18  is mounted for displacement relative to the supporting leg  15  in a direction of elongation  21  of the supporting leg  15 , extending perpendicularly to the track plane  14 , and may be connected to the supporting leg  15  by means of bolts  20 , as desired.  
      A gripper carrier  28  is mounted on the supporting leg  15  for vertical displacement in the direction of elongation  21  in a guide  24  and is connected to a clamping device  22 . A vertical adjustment drive  23  connected to the tool carrier  12  is provided for vertical adjustment of the gripper carrier  28  with the clamping device  22 . The latter comprises two pincer-like gripping elements  25  pivotable about a gripper axis  27  by means of a clamping drive  26  which is connected to the gripper carrier  28 . The clamping device  22  and the supporting leg  15  are arranged one behind the other with regard to the longitudinal direction (arrow  31 ).  
      In operation, the machine  1  is positioned, with the aid of the operating handles  7 , in such a way that the clamping device  22 —with opened gripping elements  25 —comes to lie above a spike head  29  of a rail spike  30 . With actuation of the clamping drive  26 , the two gripping elements  25  are moved towards one another with a clamping force which is selectively adjustable, thus causing the spike head  29  to be engaged in a form-fitting manner (see  FIG. 2 ). As a result of the subsequent actuation of the vertical adjustment drive  23 , the supporting plate  18  is pressed onto the tie  17  and the gripper carrier  28 , together with the clamping device  22  and the clamping drive  26 , is raised, causing the rail spike  30  to be pulled out of the tie  17 .  
      In the event of a tie  17  lying in an oblique position, the clamping device  22  can be adjusted in an optimal way to match the particular position of the rail spike  30  by temporarily loosening the blocking device  19  and swivelling the tool carrier  12 . In order to pull a rail spike  30  located on the opposite rail side, it is merely necessary to pivot the machine  1  slightly about the axis  9  until the clamping device  22  and the supporting plate  18  are lifted clear of the upper rail edge. By transversely displacing the machine  1  with the aid of the carriage  10 , the gripping elements  25  can be centered above the rail spike  30  to be pulled. The subsequent pulling operation is initiated with lowering the gripper carrier  28 .  
      Alternatively, of course, it is also possible to arrange the gripper carrier  28  fixedly on the supporting leg  15  and to adjust the supporting leg  18  relative to the supporting leg  15  in the direction of elongation  21  by means of a drive, for example, in order to thereby pull a rail spike  30  from a tie  17 .  
      While the invention has been illustrated and described as embodied in a spike pulling machine, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.  
      This application claims the benefit, under 35 U.S.C. § 119, of German patent application No. 202004010216.1, filed Jun. 30, 2004; the prior application is herewith incorporated by reference in its entirety.  
      What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents: