Patent Publication Number: US-8534195-B2

Title: Rail plate inserter

Description:
This application is a divisional of application Ser. No. 12/566,988, filed Sep. 25, 2009. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to railroad maintenance machines, and more specifically to a railway plate inserter workhead for inserting rail plates under rail ties. 
     Conventional railroad track consists of a plurality of spaced, parallel wooden ties to each of which are attached a pair of spaced rail tie plates. Each tie plate is configured to rest on an upper surface of the tie and includes holes for receiving fasteners such as spikes or screws, as well as a canted seat or a cradle formation for receiving the foot or base of the steel rail. Since two rails make up a railroad track, there is a pair of spaced tie plates on each tie. As is known in the art, some of the fasteners are used to secure the tie plate on the tie and others secure the base of the rail to the tie plate cradle. 
     When replacing worn ties, or when laying new rails on a pre-existing railroad track bed, tie plates are positioned on the railroad ties. One plate is required for each rail on a tie and the plates are initially placed adjacent the track, either by a crane or by a work gang. The plates are then non-accurately positioned upon a top surface of the tie to receive the rail. 
     In conventional railroad track maintenance, the plates are manually centered on the tie, then positioned under the rail to receive the foot of the rail in the recess of the plate. As part of this process, the rail is lifted from the tie to properly position the plate. It will be appreciated that such manual placement involves high labor costs, inconsistent accuracy of placement, and is time consuming. 
     Railways have attempted to mechanize at least portions of the plate insertion process. However, such systems have not been widely accepted by the railroads because of the relatively complicated mechanisms involved in performing the insertion. Additionally, conventional insertion machines are unable to accommodate irregularities in plate sizes and shapes. For example, plates used on curved track are larger than plates used on straight track. Deviations of as little as ⅜ of an inch in the plate are significant in automatic plate insertion machines. Due to these variations, frequent manual readjustment of settings is required in conventional plate handling equipment to accommodate different sizes and shapes of plates. 
     Railroad installation and maintenance machines typically include a workhead that pushes a previously placed tie plate underneath a rail tie. These conventional machines are unable to account for plates misaligned on the tie. Further, in cases where the plate inserter incorrectly pushes the plate underneath the tie, a worker is typically required to manually retrieve the plate under the tie, which is time consuming. Since plate handling machines are commonly one of a caravan of maintenance machines, the productivity of the maintenance of the railroad maintenance gang is limited as measured by the rate of the slowest unit. 
     Accordingly, there is a need for an improved plate inserter which reduces the manual handling of plates during the plate insertion process, and which addresses the above deficiencies of conventional plate insertion techniques and equipment. 
     SUMMARY OF INVENTION 
     Embodiments of the present invention are directed to a plate inserter workhead mounted on a moving frame that is configured for automatically squaring a plate on a tie and correctly positioning the plate under the rail. At least one of a plurality of fingers engages an opening in the tie plate and automatically pushes the plate into position. Once the plate is in position, the plate inserter workhead subsequently releases the plate. Moreover, if the plate is misaligned under the rail, the operator can retract and reinsert the plate under the rail without manual intervention from an additional worker. 
     More specifically, a preferred embodiment is directed to a finger for use in a rail plate inserter machine workhead and for positioning a rail plate predisposed on a rail tie under a rail, having a planar body having an upper arm with a hook-shaped end and including an opening for accommodating a spring, the end being configured for being contacted by a bar operatively associated with a finger lift assembly; a lower arm having a depending tip; and a middle portion joining the upper and lower arms to define an obtuse angle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary side view of a preferred embodiment of the present machine for inserting rail plates under rail ties; 
         FIG. 2  is a fragmentary front view of the present machine for inserting rail plates under rail ties; 
         FIG. 3  is a front view of the present workhead assembly located on a side of the machine of  FIG. 2 ; 
         FIG. 4  is a fragmentary side view of the centering apparatus included in the workhead assembly of  FIG. 3 ; 
         FIG. 5A  is a fragmentary side view of the squaring apparatus included in the workhead assembly; 
         FIG. 5B  is a fragmentary front view of the squaring apparatus included in the workhead assembly; 
         FIG. 6  is a side view of the workhead assembly of  FIG. 3 , depicting an opposite side from that seen in  FIG. 4 ; 
         FIG. 7A  is a fragmentary side view of the pusher included in the workhead assembly of  FIG. 3  with the fingers in a raised position; 
         FIG. 7B  is a fragmentary side view of the pusher included in the workhead assembly of  FIG. 3  with the fingers in a lowered position; 
         FIG. 8A  is a fragmentary top perspective view of the pusher included in the workhead assembly of  FIG. 3  with portions removed for clarity and shown with the fingers in a raised position; 
         FIG. 8B  is a fragmentary top perspective view of the pusher included in the workhead assembly of  FIG. 3  with portions removed for clarity and shown with at least one finger engaged in an opening in the plate; 
         FIG. 9A  is a top elevation view of the pusher assembly included in the workhead assembly of  FIG. 3  with portions removed for clarity; 
         FIG. 9B  is a side elevation view of the pusher assembly included in the workhead assembly of  FIG. 3  with portions removed for clarity; 
         FIG. 9C  is a top perspective view of the pusher assembly included in the workhead assembly of  FIG. 3  with portions removed for clarity; 
         FIG. 9D  is a side view of the finger included in the pusher assembly; 
         FIG. 10  is a front view of the present workhead assembly with portions removed for clarity and shown with the workhead in the ready position; 
         FIG. 11  is a side view of the present workhead assembly with portions removed for clarity and shown with the workhead vertical cylinder lowering the workhead body; 
         FIG. 12  is a front view of the present workhead assembly with portions removed for clarity and shown with the centering elements closed on the tie; 
         FIG. 13  is a side view of the present workhead assembly with portions removed for clarity and shown with the box cylinder extending the ram towards the rail to push the plate into position; 
         FIG. 14  is a side view of the present workhead assembly with portions removed for clarity and shown with the box cylinder retracting and at least one finger engaged in the opening in the rail plate; 
         FIG. 15  is a side view of the present workhead assembly with portions removed for clarity and shown with the box cylinder assembly and tie locating pins rotated up toward the workhead body; 
         FIG. 16  is a side view of the present workhead assembly with portions removed for clarity and shown pushing the rail plate underneath the rail; and 
         FIG. 17  is a side view of the present workhead assembly with portions removed for clarity and with the rail plate underneath the rail. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT 
     Referring now to  FIGS. 1 and 2 , a railway maintenance machine is generally designated  10  and moves along a railroad track  12  having two parallel rails  14 . Supporting the rails  14  are a connected plurality of railroad ties  16 , each positioned generally perpendicular to the rails. While wood ties are preferred, ties of other materials are also contemplated as known in the art. Preferably, a rail plate  18  is used to secure each rail  14  to the corresponding tie  16 . Each rail plate  18  is secured to the tie  16  by inserting at least one rail fastener  20 , such as a spike, through an opening  22  in the rail plate. Also, the tie  16  is provided with nesting recesses and formations for engaging the plate  18 . 
     The railway maintenance machine  10  includes a frame  26  having at least one operator workstation  28  allowing an operator  30  to ride on the machine as it travels along the track  12 , preferably by employing an engine  32 . However, other propulsion mechanisms are contemplated. The frame  26  is provided with other components including wheels  33  for movement along the track  12 . Such features are well known in the art and are disclosed in U.S. Pat. No. 5,398,616 which is incorporated by reference. At least one control system  34  is positioned near the operator workstation  28  for controlling the operation of the machine  10  as discussed below. A hydraulic remote control and a hand controller  35  is provided for operator input to the control system  34  and for moving the machine  10 . 
     The machine  10  includes a lifter  36  for elevating the rail above the tie and at least one workhead carriage  38  which is constructed and arranged to move at least one workhead assembly  40  parallel and transverse to the rails  14 . Workhead carriages  38  of this type are well known in the art (see e.g., U.S. Pat. No. 5,465,667, which is incorporated by reference). A vertical cylinder  42  on the workhead carriage  38  facilitates movement of the workhead  40  in a direction parallel to a longitudinal axis of the rail  14 . A horizontal cylinder  44  on the workhead carriage  38  facilitates movement of the workhead  40  in a direction perpendicular to the longitudinal axis of the rail  14 . 
     Referring now to  FIGS. 2 and 3 , each workhead assembly  40  is configured to move vertically between a travel position and a ready position under the control of the control system  34 . In the travel position, the vertical cylinder  42  is fully retracted to facilitate travel of the machine  10  along the track  12  and such travel is permitted by the control system  34 . When in the ready position, the vertical cylinder  42  is not fully retracted, and the machine  10  is prevented from moving in either the forward and reverse direction. This feature of the present embodiment prevents possible damage to the workhead assembly  40  by not allowing the operator  30  to propel the machine  10  when the workhead is in a lowered position. 
     The machine  10  preferably includes two workhead assemblies  40 , each being able to move independently of the other so that two rail plates  18  can be inserted simultaneously on each side of the track  14 . Included in the workhead assembly  40  is a workhead body  46  connected to, among other things, a centering apparatus  48 , a squaring apparatus  50  and a pusher assembly  52 . Collectively, the squaring apparatus  50  and pusher assembly  52  make up a workhead center  54 . 
     As shown in  FIGS. 3-4 , the centering apparatus  48  is connected to the workhead body  46  and is constructed and arranged for centering the workhead center  54  over the rail tie  16 . Also, in cases where the plate  18  is misaligned on the tie  16 , the centering apparatus  48  is configured to simultaneously center the workhead center  54  and the rail plate  18  on the rail tie  16 . The workhead center  54  is supported on a generally horizontal shaft  56  and is movable along the shaft on the workhead assembly  40  along an axis parallel to the rails  14 . In this embodiment and as best shown in  FIG. 10 , a double-sided cylinder  58  enables movement of the workhead center  54  along the shaft  56  by transferring hydraulic fluid between a first chamber  60  and a second chamber  62 . Associated with the cylinder  58  is a lock valve  64  for preventing the flow of hydraulic fluid between the first chamber  60  and the second chamber  62 . When the lock valve  64  is in a locked position, the workhead center  54  is prevented from moving along the shaft  56 . 
     Returning to  FIG. 3 , a left centering element  66  and a right centering element  68  are each attached to corresponding ends of the shaft  56 . Each centering element  66 ,  68  reciprocates laterally relative to the tie  16  and along the rail, and is operatively associated with a corresponding side  70  of the rail tie  16 . Each centering element  66 ,  68  is also pivotable about a generally vertical axis between an open position and a closed position relative to the corresponding tie side  70 . Preferably, a tie locating pin  74  for contacting a corresponding side of the rail tie  70  is included at the lower end of each centering element  66 ,  68 . 
     As shown in  FIGS. 3 and 4 , a tie locating cylinder  80  is operatively associated with each centering element  66 ,  68  for moving the pins  74  from a retracted position (shown in phantom) to an extended position, thus enabling the centering elements and attached tie locating pins  74  to converge toward the rail tie  16 . When the tie locating pins  74  converge against a corresponding side  70  of the rail tie  16 , the workhead center  54  is forced to a position directly over the center of the tie  16 . Each centering element  66 ,  68  is also associated with a centering element return spring  82  for moving each centering element away from the rail tie  16  after the convergence has taken place. 
     Now referring to  FIGS. 5A-6  and  8 A-B, the squaring apparatus  50  included in the workhead assembly  40  is located on the workhead body  46  and is constructed and arranged for squaring the rail plate  18  on the rail tie  16 . In this configuration, the squaring apparatus  50  has a box cylinder assembly  86  mounted to the workhead body  46 . 
     Included in the box cylinder assembly  86  is a fluid powered ram  88  reciprocating relative to the box cylinder assembly between a retracted position farthest from the rail  14  and an extended position closest to the rail. Also, the ram  88  is configured for engaging a rail plate seat  90  (see  FIGS. 8A-B ). Preferably, the ram  88  has hard faced edges to provide additional durability. The preferred configuration of this embodiment includes a single acting ram cylinder  92  for extending the ram  88 . Also included in this embodiment is a ram return spring  94  for retracting the ram against the cylinder  92  upon depressurization. Other configurations for extending and retracting the ram  88  are also contemplated. Additionally, a tie leveling bar  96  is mounted to the box cylinder  92  for making first contact with the rail plate  18  to level the workhead body  46  with the tie  16 . 
     The squaring apparatus  50  is configured so that when the box cylinder assembly  86  is lowered into the rail plate seat  90  (and after the workhead  54  is centered over the tie  16 ), the ram  88  extends to contact a front edge of the plate seat  98 . This extension of the ram  88  in the plate seat  90  squares the plate  18  on the rail tie  16 . Additionally, it is preferred that the squaring apparatus  50  is constructed and arranged on the workhead body  46  to operate independently of the centering apparatus  48 . 
     As best shown in  FIG. 6 , a flip cylinder  99  is also operatively connected to the box cylinder assembly  86  and centering apparatus  48  for rotating both the box cylinder assembly and the centering apparatus about a generally horizontal axis to and from the rail plate  18 . As explained subsequently, such rotation is necessary during operation of the pusher assembly  52 . 
     Referring now to  FIGS. 7A-9D , the pusher assembly  52  is included on the workhead body  46  for positioning the rail plate  18  under a selected one of the rails  14  being lifted by the rail lifter  36 . Included in the pusher assembly  52  is at least one plate engaging finger  100  constructed and arranged for engaging the opening  22  in the rail plate  18 . Preferably, the pusher assembly  52  has a plurality of plate engaging fingers  100  divided as a right set of fingers  104  and a left set of fingers  106  spaced from the right set of fingers along an axis parallel to the rails  14 . More specifically, in the preferred embodiment each set of fingers  104 ,  106  includes six plate engaging fingers  100 . However, other configurations for the number of fingers  100  and finger sets  104 ,  106  are contemplated based on design preference. 
     As best shown in  FIGS. 7A-7B , each finger  100  pivots on an axis A parallel to the rails  14 . Additionally, a finger spring  108  is attached to an end of an upper arm global  109  of each finger  100 . The force of the spring  108  against the finger  100  causes the finger  100  to be biased against the plate  18  so that the finger  100  engages the opening  22  in the plate  18 . 
     A finger lift assembly  110  is provided to overcome the force of the spring  108  and raise and lower the fingers  100 . Included with the finger lift assembly  110  is a cam lift  111  connected to a finger contact rod  112 . The finger contact rod  112  contacts the end of the upper a in  109  of the fingers  100  to facilitate lowering and raising the fingers  100 . Also included in the finger lift assembly  110  is a finger lift rocker arm  114  pivotably connected to a finger lift cylinder  116 . The rocker arm  114  connects to the cam  111  such that movement of the rocker arm causes corresponding movement of the cam. Accordingly, when the finger lift cylinder  116  and rocker arm  114  are in a retracted position ( FIGS. 7A and 8A ), the cam  111  and attached rod  112  press down against the fingers end of the upper arm  109 , causing the fingers  100  to be in a raised position. When the finger lift cylinder  116  and rocker arm  114  are in an extended position ( FIGS. 7B and 8B ), the rod  112  does not contact the end of the upper arm  109 , and the force of the spring  108  causes the fingers  100  to be in a lowered position. As should be appreciated, the finger lift assembly  110  should be of sufficient strength to overcome the force of the spring  108 . 
     Referring now to  FIG. 10 , when the workhead assembly  40  is in the ready position, using the control system  34 , and preferably the hand controller  35 , the operator  30  locates the workhead assembly  40  above the rail plate  18  previously displaced on the rail tie  16 . While operation of the present machine  10  is described as being controlled by the operator  30 , operations can also be performed automatically by the control system  34 . Automatic control is preferably controlled by a program logic controller or PLC located in the control system  34 , however other components providing automation are contemplated as known in the art (e.g., circuit boards and/or relays). Once in the ready position, the operator  30  can use the hand controller  35  as part of the system  34  to adjust the position of the workhead horizontal cylinder  44 . Further, when in the ready position, the box cylinder assembly  86  is in the lowered position, the centering elements  66 ,  68  are fully open, and the tie locate pins  74  are rotated down. 
     As best shown in  FIG. 2  over the left hand rail, once the workhead assembly  40  is positioned over the rail plate  18 , the operator  30  initiates the program logic to start automatic insertion of the rail plate  18  under the rail tie  16 . Once the automatic insertion is started, the rail lifter  36  clamps the rail  14 , and a jack cylinder  120  included in the rail lifter extends and lifts the rail a pre-determined height over a tie  16  (not shown). Referring now to  FIG. 11 , the pre-determined height is input from a measuring device (not shown) that calculates a gap distance between an upper surface of the tie  122  and a bottom surface of the rail  124 . Next, the workhead vertical cylinder  42  lowers the workhead body  46  until contact is made between the rail plate  18  and the box cylinder assembly leveling bar  96 . Once a sensor (not shown) mounted to the flip cylinder  99 , and operatively connected to the box cylinder assembly  86 , determines that a predetermined flip cylinder position is achieved, program logic in the control system  34  causes the vertical cylinder  42  to suspend lowering the workhead body  46 . 
     As best shown in  FIG. 12 , once lowering of the vertical cylinder  42  is halted, the lock valve  64  associated with the cylinder  58  is set to an unlock position so that the workhead center  54  is moveable along the shaft  56 . At the same time, the tie locate cylinders  80  are energized, causing the tie locate elements  66 ,  68  and the attached tie locate pins  74  to close against the sides  70  of the rail tie  16 . When the tie locating pins  74  converge on the tie  16 , the workhead cylinder  58  is pressurized to force the workhead center  54  to a position directly over the center of the tie. 
     Referring now to  FIGS. 8A-B  and  13 , after the workhead center  54  is centered over the tie  16 , the finger lift assembly  110  is activated and the fingers  100  are lowered down against the plate  18 . Next, the ram cylinder  92  extends from the box cylinder assembly  86  to force the ram  88  against the front edge of the plate seat  98 . This extension of the ram  88  squares the rail plate  18  on the tie  16 . At the same time, at least one of the plurality of fingers  100  engages at least one opening in the rail plate  22  while the non-engaged fingers remain pressed against the rail plate shoulder  127 . Through the pressing of the fingers  100  against the rail plate shoulder  127 , a vertical and horizontal force is applied against the plate  18 . The vertical force component presses the rail plate  18  down while the horizontal force component forces an engaged finger back edge  126  against a rail plate opening back edge  128 . Once at least one of the fingers  100  is engaged in the opening  22 , the only way to free the finger from the opening is to energize the finger lift assembly  110 . In the case where no finger  100  engages the opening  22 , the operator  30  can stop the automated process and manually repeat the finger engagement process. 
     Moving to  FIGS. 5A ,  10  and  14 , once the plate  18  is captured by at least one of the fingers  100 , the box cylinder assembly  86  retracts the ram  88 . In this embodiment, the ram cylinder  92  is depressurized and the ram return spring  94  forces the ram  88  to retract against the box cylinder  92 . At the same time, the lock valve  64  associated with the shaft  58  is set to a lock position to prevent movement of the workhead center  54 . As best illustrated in  FIG. 10 , the centering element return springs  82  return the centering elements  66 ,  68  to the open position so that the tie locating pins  74  are no longer adjacent to the tie sides  70 . Once the centering elements  66 ,  68  return to the open position, the flip cylinder  99  rotates the box cylinder assembly  86  and tie locate pins  74 ,  76  about a horizontal axis toward the workhead body  46  and away from the rail plate  18 . This rotation is best illustrated in  FIG. 15 . 
     Next, as shown in  FIG. 16 , the workhead horizontal cylinder  44  is energized to move the workhead assembly  40  toward the rail  14 , causing the engaged finger  100  to push the plate  18  underneath the lifted rail. The plate  18  is advanced underneath the rail  14  until a pressure sensor  129  located on the horizontal cylinder  44  reaches a pressure threshold. At this point, program logic stops movement of the horizontal cylinder  44  and the automatic insertion process is stopped. 
     After the automatic insertion process is stopped, the operator  30  has several options. If the operator  30  is visually satisfied with insertion of the plate  18 , the operator can end the cycle, and prepare the machine  10  to move to the next tie  16 . A plate  18  positioned under the rail tie is shown in  FIG. 17 . In this event, the machine  10  will lower the rail jack  120 , unclamp the rail  14 , lift any engaged fingers  100  out of the rail plate opening  22  and return the workhead assembly  40  to the ready position. Alternatively, the operator  30  can choose to maneuver the rail plate  18  back out from underneath the rail  16 , and reattempt the plate insertion. 
     Unlike conventional plate placement machines, a feature of the present machine  10  is the ability to reposition a rail plate  18  already underneath a rail  14  without intervention from an additional worker. This functionality is possible because the finger  100  is designed to engage an opening in the rail plate  22  and is reciprocally movable relative to the rail  14 . 
     The finger  100  for use in the rail plate inserter machine workhead  46  and for positioning the rail plate  18  predisposed on the rail tie  16  under the rail  14  will now be described with reference to  FIG. 9D . The finger  100  includes a body  101  that is preferably generally planar forming a generally boomerang or rocker shape. Included in the body  101  are the upper arm  109  and a lower arm  130  having a tip  132 . Additionally, an end  134  of the upper arm  109  has a hook-shape. Also included in the upper arm  109  is an opening  136  for accommodating the spring  108 . Further, the upper arm  109  is configured for being contacted by the rod  112  operatively associated with the finger lift assembly  110  ( FIGS. 7A and 7B ). More specifically, the upper arm  109  includes a curved surface  137  that allows the rod  112  to contact the finger  100  while minimizing wear on the rod and finger. A middle portion  138  integrally joins the upper and lower arms  109 ,  130 . The upper and lower arms  109 ,  130  are angled relative to the middle portion  138  to define an obtuse angle a. The middle portion  138  preferably further includes a semi-circular recess  140  located on a bottom edge  142 . Additionally, a pivot axis aperture  144  is preferably located between the upper arm  109  and the lower arm  130  to accommodate the axis A. Finally, the tip  132  depends from the lower arm  130  at an angle approximately perpendicular to the lower arm. 
     While particular embodiments of the present machine for inserting rail plates under a rail have been described herein, 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.