Patent Publication Number: US-8522688-B2

Title: Rail anchor spreader-squeezer

Description:
BACKGROUND 
     The present invention relates to rail maintenance equipment, and specifically to maintenance equipment for spreading and squeezing anchor position with respect to the tie. 
     A rail anchor clamps onto a rail and is typically applied in pairs, one on each side of a rail tie to resist longitudinal movement of the rail relative to the supporting tie. In the course of rail maintenance, wooden ties are often replaced by pulling them transversely from beneath the rails. A part of this operation is the mechanical spreading of the anchors laterally away from edges of the tie to facilitate old tie removal and the insertion of new tie. An example of a conventional anchor spreader is U.S. Pat. No. 5,117,760. In some cases, through use, the anchors become embedded in the sides of the tie, and are difficult to remove. Existing anchor removers such as the model disclosed in the &#39;760 patent have been known to have difficulty in removing such embedded anchors. 
     Upon replacement of the tie, the previously spread anchors are mechanically squeezed into place to secure the new tie. Typically, railroads employ distinct, single task-oriented machines in this process, one restricted to anchor spreading, and the other to anchor squeezing. Thus, according to conventional railroad right of way maintenance procedures, the railroads have to change machines when the anchors are to be repositioned after tie replacement. 
     One conventional type of a task-specific anchor squeezing machine is disclosed in U.S. Pat. No. 5,277,122. This device employs a pivoting actuator for positioning the anchors. In practice, this device has been known to cause misalignment of the anchors on the rail, to the extent that the anchors disengage from the rail as trains pass over them. 
     Another factor in designing rail maintenance equipment for spreading and squeezing anchors is that the width of railroad track rails changes across the US due to manufacturing differences. Thus, a typical rail anchor spreader or squeezer must often be adapted or modified to accommodate these variations so that proper operation is maintained. 
     SUMMARY 
     The above-identified drawbacks of prior art anchor spreaders and squeezers are addressed by the present rail maintenance machine having an anchor spreader/squeezer work head. One feature of the present work head is that it has the capability for both squeezing anchors and spreading them, the conversion being achieved by an alternate function on the control system, which changes the sequence in laterally moving sliding brackets. Also, task-specific tools are interchangeably mounted to free ends of the sliding brackets. 
     Another feature of the present work head is that the same sliding brackets can spread the anchors by direct contact, and alternatively by grasping the rail tie plate located between the rail base and the upper surface of the tie, may employ the tie plate as a hammer reciprocating in the direction of the rail for facilitating the dislodging of anchors from the sides of the tie. 
     Still another feature of the present work head is that it is provided with an anchor-engaging tool configured for accommodating variations in rail base widths. Thus, anchor spreading or squeezing work in the field need not be interrupted by the installation of various anchor-engagement tools tailored for specific rail base widths. 
     More specifically, a rail maintenance anchor spreader/squeezer work head is provided and includes a work head frame, a pair of sliding brackets laterally reciprocating on the frame, each bracket having an anchor engaging end, and a pair of opposed fluid power cylinders secured to the frame, each cylinder connected to a respective one of the sliding brackets for laterally reciprocating the sliding brackets for one of anchor squeezing, when both cylinders are extended, and anchor spreading when at least one of the cylinders is retracted. 
     In another embodiment, a rail anchor spreader/squeezer machine is provided and is configured for selectively squeezing or spreading anchors on a rail of a railroad track. The machine includes a machine frame having a front frame end and a rear frame end. At least one work head is mounted to the frame and is reciprocably movable relative to the track between a working position and a travel position. A control system connected to the work head, and the work head is capable of performing anchor spreading and anchor squeezing depending on an operational sequence determined by the control system. 
     In still another embodiment, a tool is provided for use with a rail maintenance anchor spreader/squeezer having at least one sliding bracket with a work arm having an anchor engaging end. A tool body has a mounting end and an opposite anchor work end, the anchor work end including at least one impact surface. The tool body is provided with a rail following surface extending transverse to the mounting end and to the work end, and parallel to a corresponding rail of a railroad track. In addition, the following surface is stepped for accommodating variations in rail base width. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a rail maintenance machine equipped with the present anchor spreader/squeezer work head; 
         FIG. 2  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the present anchor spreader/squeezer work head in a travel position; 
         FIG. 3  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head in a ready or working position; 
         FIG. 4  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head in a tie plate engaging position; 
         FIG. 5  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head using the tie plate to spread a first or forward anchor; 
         FIG. 6  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head using the tie plate to spread a second or rearward anchor; 
         FIG. 7  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head in a ready position after two anchors have been spread; 
         FIG. 8  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head fitted with tools for direct contact anchor spreading and shown in a ready position; 
         FIG. 9  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head of  FIG. 8  in an anchor engaging position; 
         FIG. 10  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head of  FIG. 8  in an anchor spreading position; 
         FIG. 11  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head of  FIG. 8  in a ready position after spreading two anchors; 
         FIG. 12  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head fitted with tools for directly squeezing two anchors and shown in the ready position; 
         FIG. 13  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head of  FIG. 12  engaging two anchors for squeezing them against a tie; 
         FIG. 14  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head of  FIG. 12  after squeezing the anchors against the tie; 
         FIG. 15  is a fragmentary top perspective view of the machine of  FIG. 1  depicting the work head of  FIG. 12  in the ready position after squeezing both anchors; 
         FIG. 16  is a fragmentary front view of the control panel of the machine of  FIG. 1 ; 
         FIG. 17  is a fragmentary top perspective exploded view of a lower end of the present work head depicted with the tool of  FIG. 2 ; 
         FIG. 18  is a fragmentary top perspective exploded view of a lower end of the present work head depicted with the tool of  FIG. 8 ; 
         FIG. 19  is a fragmentary top perspective exploded view of a lower end of the present work head depicted with the tool of  FIG. 12 ; 
         FIG. 20  is a fragmentary front view of the present work head shown with the tool of  FIG. 12  engaged on a rail; 
         FIG. 21  is a control system flow chart supporting the operation depicted in  FIGS. 2-7 ; 
         FIG. 22  is a control system flow chart supporting the operation depicted in  FIGS. 8-11 ; and 
         FIG. 23  is a control system flow chart supporting the operation depicted in  FIGS. 12-15 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , a rail maintenance machine suitable for use with the present anchor spreader/squeezer work head is generally designated  10 . As is known in the art, the machine  10  is designed for use in maintaining a railroad track  12 , including a pair of spaced rails  14  resting on tie plates  16  located upon transversely arranged ties  18 . The ties  18  are typically made of wood or concrete, and when wooden, they require periodic replacement. The rails  14  and the tie plates  16  are secured to the ties  18  by spikes or other fasteners (not shown) as is well known in the art. A space between the rails is referred to as the gage area, and the space external to the rails is referred to as the field area, so each rail  14  has a gage side  20  and a field side  22  ( FIG. 1 ). 
     It is common for a track  12  to be provided with pairs of anchors  24  located on sides  26  of selected rail ties  18 . Anchors  24  (Best seen in  FIG. 20 ) are generally crescent-shaped clips of steel which are configured to frictionally grasp the rail adjacent the tie. When provided on either side of the tie  18 , the anchors  24  prevent linear misalignment or racking of the track  12  during use. During rail maintenance, it is typical to periodically replace the rail ties  18 . In order to replace the tie, the fasteners (typically spikes) are first removed, and then the anchors are either removed or spread apart to create a clearance for the tie  18 , which is removed transversely relative to the track. A suitable tie removing machine is disclosed in U.S. Pat. No. 6,463,858 which is incorporated by reference. 
     Included on the machine  10  is a frame  26  having wheels  28  suitable for travel on the rails  14 . An engine  30  powers the wheels  28  through a hydraulic system  32 , including a fluid reservoir, pump, manifold and valves as is known in the art. The engine  30  also provides power for other functions of the machine  10 . An operator&#39;s cab  34  is mounted to the frame  26  and includes a control system  36 , an operator&#39;s station (not shown), as well as windows  38  through which the operator can view the track  12  being worked on. 
     Also visible through the windows  38  is at least one and preferably a pair of anchor spreader/squeezer work heads  40 , suspended from a vertically projecting, central truss  42  of the machine frame  26 . Each work head  40  is movable relative to the truss  42  between a travel position, spaced away from the rails  14 , and a working position, spaced relatively closer to the rails, by actuation of a fluid power lift cylinder  44 . In the present application, “fluid power” refers to hydraulic or pneumatic cylinders, but hydraulic cylinders are preferred. It will be appreciated that the machine  10  preferably is equipped with a pair of work heads  40 , one associated with each of the rails  14 , however only one such work head will be discussed. It will be appreciated that on the machine  10 , both work heads  40  operate in the same direction at the same time as described below. 
     An important feature of the present work head  40  is that the same unit can perform multiple anchor-related functions. Specifically, the work head  40  can both squeeze anchors together and spread anchors apart, depending on commands provided by the control system  36 . In addition to these functions, as an option the work head  40  is also configured so that a selected rail tie plate  16  is grasped and used as a hammer reciprocating along the rails  14  for sequentially impacting each of a selected pair of the anchors  24 . 
     Referring now to  FIG. 2 , a work head frame  46  is slidably coupled to the central truss  42  and is selectively moved relative to the truss by the lift cylinder  44 . Included on the work head frame  46  is a pair of spaced, parallel main plates  48  generally aligned with the rail. Oriented between the main plates  48  are upper and lower guide shafts,  50  and  52 . The shafts  50 ,  52  are located in a work zone  54  generally defined between inner edges  56  of the plates  48  and extending towards the track  12 . 
     Each work head  40  has at least one and preferably a pair of guide wheels  58  connected to the main plates  48  for maintaining alignment of the work head relative to the rail  14 . As is known in the art, the guide wheels  58  preferably have a concave periphery for facilitating engagement with a head  60  of the rail  14 . Inboard of the guide wheels  58  and closer to the work zone  54  is at least one and preferably a pair of rail clamps  62 . While a variety of rail clamp mechanisms are contemplated, in the preferred embodiment, each rail clamp includes a pair of pivoting pincer arms  64  connected by fluid power clamp cylinders  66  transversely mounted relative to the rail  14  between upper ends  68  of the arms. Each pincer arm  64  is connected to the work head frame  46  at a pivot bracket  70  including a pivot pin  72  generally parallel to the rail  14 . Operation of the clamp cylinders  66  is controlled by the control system  36 . In general, extension of the cylinders  66  spreads the upper ends  68  of the arms  64 , creating a clamping force. Similarly, retraction of the cylinders  66  brings together the upper ends  68  of the arms  64 , releasing the clamping force on the rail  14 . 
     Referring now to  FIGS. 2-5 ), the work zone  54  is at least one and preferably a pair of sliding brackets  74  laterally reciprocating on the upper and lower guide shafts  50 ,  52 . The operation of the brackets  74  is along an operational axis which is parallel to a longitudinal rail axis defined by the rails  14 . While other constructions are contemplated, each sliding bracket  74  includes a pair of spaced, parallel work arms  76  separated by a bushing  78  ( FIG. 4 ) slidably engaging the respective guide shafts  50 ,  52 . The work arms  76  are respectively associated with the field side  22  and the gage side  20  of the rail  14 . Each bracket  74  is connected to a corresponding fluid power (preferably hydraulic) cylinder  80  disposed between the main plates  48  of the work head frame  46  and oriented to be parallel to the rails  14  and in opposing relationship to each other. In other words, ends of corresponding rods of the cylinders  80  are preferably disposed to face each other. However, it is also contemplated that in some applications the disposition of the cylinders  80  is reversed, with the cylinder bodies facing each other. Also, in the preferred embodiment, the cylinders  80  are disposed between and generally parallel to the guide shafts  50 ,  52 . 
     Rods of the cylinders  80  are preferably connected to the work arms  76  so that retraction or extension of the rods via selective pressurization of the cylinders  80  will cause movement of the brackets  74  along the guide shafts  50 ,  52  in the work zone  54 . In the preferred embodiment, the cylinders  80  are double acting, however, it is also contemplated that single acting, spring-return cylinders are also suitable. 
     Thus, it will be seen that the opposed cylinders  80 , controlled by the control system  36 , are each connected to a respective one of the sliding brackets  74  for laterally reciprocating the sliding brackets for any one of anchor squeezing, when both of the cylinders  80  are extended (referring to the rod action), and anchor spreading, when at least one of the cylinders is retracted. It is contemplated that the above-described configuration of the work head frame  46  may vary to suit the application as long as the functional operations of anchor squeezing and spreading by the sliding brackets  74  are achieved. 
     Referring now to  FIGS. 17-19 , in addition, each bracket  74  has an anchor engaging end  82  provided with at least one and preferably a pair of mounting bores  84  for selective attachment of one of a selected type of anchor tools  86 , to be described in greater detail below. It will be seen that each work arm  76  of each sliding bracket  74  has a corresponding anchor tool  86 . Structural support for the work head frame  46  in the work zone  54  is provided by a pair of support bars  88  secured at corresponding ends to the main plates  48 . 
     Referring now to  FIGS. 2-7 , the work head  40  will be described in greater detail in the context of the optional anchor spreading operation where the tie plate  16  is used as a reciprocating hammer for spreading the anchors  24 . Initially, in  FIG. 2 , the work head  40  is raised above the rail  14  in the travel position through action of the lift cylinder  44 . It will be seen that in this position, the guide wheels  58  are not in contact with the rail  14 , and suspension rods  90  for the guide wheels are extended relative to mounting blocks  92  which slidably receive the suspension rods  90 . As with all of the cylinders in the present machine  10 , the lift  44  is under the control of the control system  36 . 
     Referring now to  FIG. 3 , the lift  44  has lowered the work head  40  to the ready or working position, in which the guide wheels  58  are in contact with the rail head  60  and the anchor tools  86  are aligned with the rail head. At this point, both of the cylinders  80  are retracted, so that the sliding brackets  74  are spaced apart from each other, and are adjacent inner margins of the main plates  48 . Note that in this rail maintenance operation, the spikes or other fasteners have been removed from the ties  18  to be removed. 
     Since the cylinders  80  are identical to each other, but each operates a respective sliding bracket  74 , they will now be referred to as a front cylinder  80   a  associated with a front of the machine  10  and farther from the operator&#39;s cab  34 , and a rear cylinder  80   b,  associated with a rear of the machine and closer to the operator&#39;s cab. The corresponding sliding brackets  74 , as well as the anchors  24  being squeezed or spread, and the front and rear ends of the machine frame  26  will also be designated “a” and “b.” Further, the following operational discussion can be reviewed in flow chart logic sequence in relation to  FIG. 21 . 
     Referring now to  FIG. 4 , the lift cylinder  44  extends further, lowering the work head  40  so that the anchor tools  86  are adjacent the anchors  24  and the tie plate  16 . This is known as the ready or working position, as indicated in box  94  of  FIG. 21 . At this time, the rail clamp cylinders  66  extend, so that the work head  40  is clampingly engaged upon the rail  14 , as seen in box  96  of  FIG. 21 . Next, as seen in  FIG. 5  and in box  98  of  FIG. 21 , the control system  36  causes the rear cylinder  80   b  to extend, pushing the corresponding sliding bracket  74   b  towards the front bracket, in so doing engaging and pushing the tie plate  16  towards the front bracket, spreading the front anchor  24   a  and clamping the tie plate  16  between the anchor tools  86 . During this motion, the front cylinder  80   a  is held in place. 
     Next, referring to  FIG. 6 , and box  100  of  FIG. 21 , the front cylinder  80   a  extends simultaneously with retraction of the rear cylinder  80   b,  causing the grasped tie plate  16  to move rearwardly. In other words, the cylinders  80   a,    80   b  complementarily extend and retract to move the tie plate  16  to spread the second anchor  24   b  in an opposite direction from the first anchor  24   a.  In this motion, the tie plate  16  engages and spreads the rear anchor  24   b  away from the tie  18 . Upon completion of this operation, the anchors  24   a,    24   b  are sufficiently spread to accommodate removal of the tie  18 . As seen in box  102  of  FIG. 21 , the front cylinder  80   a  retracts, and the rear cylinder  80   b  is held in place so that the anchor tools  86  are spread apart to release the tie plate  16 . 
     Preferably simultaneously, the rail clamp cylinders  66  retract (box  104 ) releasing the rail clamps  62  and the lift cylinder  44  retracts (box  106 ) to pull the work head  40  upward ( FIG. 7 ). As seen in  FIG. 21 , the control system  36  is configured so that actuation of a single button F 4  on a joystick  108  initiates the complete automatic sequence depicted in boxes  94 - 106 . 
     Referring now to  FIGS. 8-11  and  22 , an embodiment is depicted in which the machine  10  is configured for anchor spreading without using the tie plate  16 . Instead, specialized anchor tools  110  are provided, being generally wedge shaped or downwardly tapered, while still being mounted to the common mounting bores  84  at the anchor engaging end  82  of the work arms  76 . It is anticipated that the anchor tools  86 ,  110  may be readily interchanged by the operator or in a railroad maintenance shop, as by removing fasteners such as cotter pins  112  retaining mounting pins  114  holding the tool in place in the bores  84 . 
     In describing the operation of this embodiment, steps which are identical to those described in relation to  FIGS. 2-7  and  21  will be designated with the same reference numbers. Referring first to  FIG. 8 , the work head  40  is lowered by the lift cylinder  44  so that the guide wheels  58  contact the rail head  60 . Note that both of the cylinders  80   a,    80   b  are in the extended position, so that the sliding brackets  74  are in contact with each other in the middle of the work zone  54 . In this view, cylinder rods  116  are visible. 
     Referring now to  FIGS. 9 and 22 , upon actuation of button F 4  on the control system joystick  108 , the lift cylinder  44  lowers the work head  40  to the ready position between the anchors  24   a,    24   b  as indicated in box  94 , and the rail clamp cylinders  66  are activated to clamp the rail  14  as seen in the box  96 . Next, referring to  FIGS. 10  and box  118  of  FIG. 22 , both cylinders  80   a  and  80   b  are simultaneously retracted, causing the anchor tools  110  to engage and spread the anchors  24   a,    24   b.    
     The degree of anchor spread, or the retraction of the cylinders  80   a,    80   b  may vary to suit the situation, and may not always be a full retraction. Furthermore, in some situations it is contemplated that only one of the sliding brackets is employed for spreading only one of the anchors  24   a,    24   b,  since such spreading is all that is required to clear the tie  18  for removal. As such, the operational cycle is be modified accordingly 
     Referring now to  FIGS. 11  and box  120  of  FIG. 22 , both cylinders  80   a,    80   b  are extended again to contact each other, and as such are ready to begin another spreading cycle. In conjunction with this step, the rail clamp  62  is released (box  104 ) and the lift cylinder  44  is retracted (box  106 ). Since the process is controlled by the control system  36 , the cylinder extension of box  120  and the release and retraction of boxes  104  and  106  occur simultaneously to decrease cycle time of the machine  10 . 
     Referring now to  FIGS. 12-15  and  23 , another embodiment of the present machine  10  is described, this one configured for anchor squeezing. As in the previously described embodiments, reference numbers for shared components and flow chart sequence steps are reapplied. In the anchor squeezing mode, the anchor engaging ends  82  of the work arms  76  are equipped with a specialized anchor squeezing tool  122  described in greater detail below, and mounted to the mounting bores  84  in similar fashion to the anchor tools  86  and  110 . 
     Referring now to  FIGS. 13 and 23 , the work head  40  is shown in the ready or working position, upon actuation of the button F 4  on the joystick  108 , having been lowered by the lift cylinder  44  (box  94 ) and the rail clamp  62  engaged (box  96 ). In this embodiment, the “start” position of the cylinders  80   a,    80   b  is retracted so that the sliding brackets  74   a,    74   b  are spread apart. Thus, as the cycle begins, the anchor spreader tools  122  are located outside, or farther from the tie  18  relative to the anchors  24   a,    24   b.    
     Referring now to  FIG. 14  and box  124  of  FIG. 23 , both cylinders  80   a,    80   b  are extended simultaneously, engaging and pushing the anchors  24   a,    24   b  against the sides  26  of the tie  18 . Upon completion of this step, and referring to  FIG. 15  and box  128  of  FIG. 23 , the cylinders  80   a,    80   b  are retracted, the rail clamp  62  is released (box  104 ), and the lift cylinder  44  retracted (box  106 ), all simultaneously to reduced cycle time and to prepare the work head  40  for the next operation. 
     Referring now to  FIG. 16 , a portion of the control system  36  is depicted, including a control panel  128  with a spreader mode switch  130 . The operator has the option of performing the anchor spreading operation using a rail tie plate  16  as described in relation to  FIGS. 2-7 , by selecting “w/tie”  132 , or using only the anchor tools  110  as described in relation to  FIGS. 8-11  by selecting “w/o tie”  134 . 
     Referring now to  FIGS. 17-19 , the present anchor engaging ends  82  of the work head  40  are provided with at least one type of an interchangeable anchor tool  110  configured for anchor spreading, the squeezing tool  122  and the tie plate clamping tool  86 . More specifically, each tool  86 ,  110 ,  122  includes a tool body  136  having a mounting end  138  configured for engaging the clevis-like anchor engaging end  82  and having throughbores  140  in registry with the mounting bores  84 . Opposite the mounting end  138  is an anchor head or anchor work end  142  with at least one impact surface  144 . In the case of the spreader tool  110 , there are two such surfaces  144  so that one type of tool is usable on both front and rear sliding brackets  74   a    74   b.    
     In the case of the tools  86  and  122 , the anchor head  142  is vertically offset from the mounting end  138  and depends from a side edge  146  of the mounting end. This orientation provides the work head  40  with the required increase in width of operational travel needed for anchor squeezing, and also for grasping the tie plate  16  when the embodiment of  FIGS. 2-7  is selected. 
     Referring now to  FIG. 20 , the tools  110  and  122  preferably include a rail following surface  148  projecting transversely relative mounting end  138  and the work end  142 , and parallel to the rail  14 . As depicted, the tool  110  of  FIG. 20  corresponds to the tool as depicted in  FIG. 8 . In addition, the rail following surface  148  is stepped for accommodating variations in the width of a rail base  150 . While other configurations are contemplated, the preferred rail following surface  144  has a step pattern accommodating a wider rail base  150  near a bottom of the tool  110 ,  122 , and a narrower base near an upper end of the tool. An advantage of this construction is that one tool  110 ,  122  is usable on a variety of track configurations, and reduces the inherent downtime of track machinery for changing tools to properly work on different types or brands of rails. Also, in the case of the tools and  122 , the stepped rail following surface  148  is on the same portion of the tool as the anchor head  142 , found on the side edge  146 . In the case of the anchor tool  110 , the rail following surface  148  projects from a central portion of the body  136 . 
     While a particular embodiment of the present rail anchor spreader-squeezer has been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.