Combined tie extractor and plate remover for rail maintenance

Information

  • Patent Grant
  • 6755135
  • Patent Number
    6,755,135
  • Date Filed
    Tuesday, September 3, 2002
    22 years ago
  • Date Issued
    Tuesday, June 29, 2004
    20 years ago
Abstract
A combined tie extractor and plate remover for railroad track maintenance includes a frame configured for movement along the track and having a first side corresponding to a first side of the track and a second side corresponding to a second side of the track, each side of the track having a corresponding rail. A rail lifting apparatus associated with the frame is configured for lifting a selected one of the first and second rails away from the track. A plate remover assembly associated with the frame is configured for grasping and removing tie plates associated with each side of the track from a selected tie. At least one tie extracting assembly is disposed on the frame for extracting the gripped tie transversely relative to the track in conjunction with the removal of the tie plates.
Description




BACKGROUND OF THE INVENTION




This application relates generally to railway right-of-way maintenance equipment of the type used to repair and maintain railroad track. More specifically, the present invention relates to an apparatus for replacing rail ties and for handling rail tie plates during rail tie replacement.




Conventional railroad track consists of a plurality of spaced parallel wooden ties to which are each attached a pair of spaced rail tie plates. Each tie plate is configured to rest on the upper surface of the tie and includes holes for receiving spikes or screws, as well as a canted seat or a cradle formation for receiving the bottom of the steel rail. Since two rails make up a railroad track, there is a pair of spaced tie plates on each tie. Some of the spikes are used to secure the tie plate on the tie and others are used to secure the base of the rail to the tie plate cradle.




During track maintenance operations, it is common to periodically remove worn out or rotten ties. This is accomplished by first removing the spikes which hold the plates to the tie as well as to the rail. Railroad ties are typically removed and replaced using specially designed machines. Generally, the tie replacing machines roll along the railroad track and stop at a tie needing replacement. Most machines have an extending member that positions a gripping device normally relative to the track and adjacent to an end of a rail tie to remove it. The gripping device has vice-like jaws that clamp onto the end of the rail tie (other machines have a pushing mechanism which pushes the loosened tie transversely from the track). Then, the extending member extends normally away from the track, and thereby removes the tie from under the railroad track. The reverse operation is used to insert a new tie under the track.




Although these prior machines are able to remove and replace the railroad ties, the machines are subject to several disadvantages. One disadvantage is that the extending members on the prior machines are relatively unstable. On the prior machines, the extending members are attached to the railroad repair machine frame at the center of the members. In operation, each member has an inner portion that is slidingly engaged within an outer portion and telescopes away from the frame to position the gripping mechanism relative to the rail tie. The length of the fully extended member places stress at the attachment point where the end of the member meets the frame. This stress often causes the member to sag, work improperly or even break over time. Furthermore, some prior machines only had one extending member, which was attached to a pivot, in order to remove ties from the other side of a track if necessary. These machines experienced additional stress at the attachment point due to the excess movement and vibration on the extending member.




More recently developed machines include two extending members, one on each side of the machine that are mounted along the same axis. A main support member is situated in the middle of the machine frame and contains the two extending members which are slidingly engaged with each other. This innermost member extends in an opposite direction from the next outer member. In operation, one extending member slides outward within the main support member, and away from the machine frame, towards the location of the rail tie.




The dual in-line extending member design increases efficiency and overcomes the stress experienced by the single pivoting extending member design. These machines can remove a rail tie from either side of a track without pivoting, however stress problems still occur when the extending member is completely extended away from the frame. The full extension places most of the weight of the extending member on the minimal contact point between the extending member and the main support member. Stress is created on the contact point between the main support member and extending member, and failure results.




As the tie is extracted, the loosened tie plates either fall into the rail bed or ballast, or are retained on the removed tie. Conventional practice is to manually remove the plates and throw them off to the side of the ballast so that they do not interfere with the replacement of the new tie. Once the new tie is inserted under the raised track, the plates must be reinserted in the appropriate position to support the rail and for re-spiking.




To avoid on the job injuries, especially those involved with handling tie plates, which typically weigh approximately 18-40 pounds and are heavy to manipulate, railways have attempted to mechanize the tie replacement and plate placement process as much as possible. One attempt has been to provide a mechanism which grips the plates and secures them to the rail as the tie is removed from beneath the plates. This system has not been widely accepted by the railroads because of its relatively complicated mechanism, and because in many instances the insertion of the new tie will cause particles of railway ballast to be retained on top of the tie and interfere with the repositioning of the tie plates. These conventional mechanisms have no way to remove unwanted ballast particles from the top surface of the tie.




Another drawback of conventional mechanized plate placement devices is that their speed is relatively slow and they cannot keep up with the other operations of the rail maintenance gang. Using manual removal and placement of tie plates, the tie replacement process typically operates at a rate of about 15 ties per minute. Conventional mechanized plate removal devices operate in the range of 3 to 5 ties per minute. At this point, this rate of production is unacceptable to the railroads.




Thus, there is a need for improved rail maintenance machinery which addresses the above-listed drawbacks by synchronizing the operations of tie extraction and plate handling. In addition, there is a need for an improved tie plate handling apparatus which addresses the problem of tie plates getting in the way of the tie extraction process. Another need in the industry is an improved plate handling system which reduces the manual handling of plates during the tie replacement process.




BRIEF SUMMARY OF THE INVENTION




The above-listed goals are met or exceeded by the present combined tie extractor and plate remover, which features the ability to grasp tie plates independently of the tie extraction procedure. In this manner, the tie plates do not interfere with the extraction and/or subsequent insertion of ties. Also, the tie plate remover assembly is preferably movable relative to the main machine frame, which allows the removed tie plates to be released remotely from the location of the tie extraction. In addition, when two non-axially aligned tie gripping extending members are provided on the frame, the movable tie plate remover assembly may be selectively movable to reference points associated with each of the extending members for operation on either side of the frame or either rail.




More specifically, a combined tie extractor and plate remover for railroad track maintenance includes a frame configured for movement along the track and having a first side corresponding to a first side of the track and a second side corresponding to a second side of the track, each side of the track having a corresponding rail. A rail lifting apparatus associated with the frame is configured for lifting a selected one of the first and second rails away from the track. A plate remover assembly associated with the frame is configured for grasping and removing tie plates associated with each side of the track from a selected tie. At least one tie extracting assembly is disposed on the frame for extracting the gripped tie transversely relative to the track in conjunction with the removal of the tie plates.




In another embodiment, a method for extracting ties and removing plates from a railroad track having a first and a second rail, includes gripping both tie plates located upon a tie to be extracted using a tie plate gripping assembly, lifting one or both of the rails of the track at a selected location of a tie extraction, pulling the tie plates away from the tie, grasping an end of the tie to be extracted adjacent the location where the rail is lifted, the grasping being performed by a tie gripping and extraction assembly, pulling the grasped tie transversely relative to said track from the point where the rail was lifted, and releasing the gripped plates.











BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS





FIG. 1

is a front perspective view of a rail tie extraction apparatus incorporating the present plate removing assembly, shown fragmentary;





FIG. 2

is an enlarged fragmentary view of the apparatus of

FIG. 1

showing the plate removing assembly with portions removed for clarity;





FIG. 3

is a top perspective view of the present plate removing assembly;





FIG. 4

is a schematic plan view of the present plate removing assembly connected to the present rail tie extraction apparatus when working on a first side of the track;





FIG. 5

is a schematic plan view of the present plate removing assembly connected to the present rail tie extraction apparatus when working on a second side of the track; and





FIG. 6

is a hydraulic schematic of the present control system for the plate removing assembly.











DETAILED DESCRIPTION OF THE INVENTION




Referring now to

FIG. 1

, a rail tie extraction apparatus incorporating the present invention is generally designated


10


and is configured for movement (preferably, but not exclusively, self-propelled) along a railroad track


12


. As is well known in the art, the track


12


includes first and second rails


14


,


16


which are connected to ties


18


using tie plates


20


and spikes


22


(plates and spikes shown in FIG.


3


). As is well known, the ties


18


are typically wood, but are also made of concrete in some applications. The present application is concerned with track laid upon wooden ties


18


, which periodically need replacement due to natural deterioration.




Furthermore, the apparatus


10


includes a frame


24


supported on a plurality of wheels


26


so that the frame can be driven along the rails


14


,


16


. The frame


24


supports a source of motive power such as an internal combustion engine


27


which also powers a fluid power system used for operating the various rail maintenance equipment found on, or associated with, the frame


24


. In the preferred apparatus


10


, the fluid power system is hydraulic, however other fluid power systems are contemplated, but are less desirable. An operator's cab


28


is mounted to the frame


24


and includes a control system


30


(best seen in FIG.


6


). As is known in the art, a main component of the control system


30


is a Programmable Logic Controller (PLC).




The frame


24


has a first side


32


corresponding to a first side


34


of the track


12


and associated with the rail


14


, and a second side


36


corresponding to a second side


38


of the track and associated with the rail


16


. In addition, the frame


24


has a first or front end


40


and a second or rear end


42


. In the preferred embodiment, the operator's cab


28


is situated nearer to the rear end


42


of the apparatus


10


and enables the operator to observe and control repair operations on either rail


14


or


16


. However, other locations for the cab


28


are contemplated. Also, an important feature of the present invention (seen schematically in

FIG. 4

) is that a first extending member


44


and a second extending member


46


are attached to the frame


24


in a non-axial relationship to each other, and each control the positioning of a corresponding gripping mechanism


48


relative to the plurality of the rail ties


18


. In the preferred embodiment, the first and second extending members,


44


,


46


, are positioned directly adjacent to each other, but it is also contemplated that first and second extending members may be positioned in spaced apart orientation at other locations along the frame


24


.




As is known on other such rail maintenance equipment, a rail lifting apparatus


49


is provided to lift a selected one of the rails


14


,


16


in close proximity to the tie


18


selected for replacement. The particular rail


14


,


16


which is lifted is the side of the track


12


from which the tie


18


will be extracted. It is this same side of the track


12


from which the spikes


22


were previously removed from the plates


20


by other equipment as is known in the art.




The extending members


44


,


46


are configured to telescope longitudinally from the frame


24


such that when the gripping mechanism


48


engages the end of a selected tie


18


, the telescoping movement pulls the tie transversely away from the track


12


. An advantage of the present apparatus


10


is that a plate removing assembly, generally designated


50


is provided to automatically grasp and retrieve the previously de-spiked tie plates


20


in conjunction with the tie extraction. In the application, tie extraction is understood to mean either pulling of the ties using a gripping mechanism as described herein, or pushing the ties transversely relative to the track


12


.




Referring now to

FIGS. 2 and 3

, the plate removing assembly


50


includes a remover frame or buggy


52


supported on rail wheels


54


for movement along the track


12


relative to the apparatus


10


. A front end


56


of the remover frame


52


is associated with the front end


40


of the frame


24


, and a rear end


58


of the remover frame is associated with the rear end


42


of the frame


24


. The operational details of the plate remover assembly


50


are provided in commonly-assigned Ser. No. 10/113,585, filed Mar. 29, 2002, which is incorporated by reference. While the plate remover assembly


50


is preferred as described above, it is contemplated that the benefits of the present invention may be equally achieved by employing other conventionally known technology for grasping and handling plates, including, but not limited to magnetic apparatus, air suction devices, or other devices not employing mechanical gripping jaws as described above. It will be understood that “plate removing” encompasses all of these technologies.




Basically, the tie plate remover assembly


50


includes at least one and preferably two subframes


60


, each with an associated plate gripping assembly


62


, including opposing plate gripping jaws


64


. The jaws


64


move reciprocally under fluid power control in the direction of the rails


14


,


16


. In addition, a retracting mechanism


66


is provided to pull the gripped tie plates


20


away from the tie


18


. A subframe


60


including a plate gripping assembly


62


and opposing jaws


64


is provided for each rail


14


,


16


so that both plates


20


located on a single tie


18


may be removed prior to the extraction of the tie from the track


12


.




Upon operator actuation of the control system


30


which activates a plate gripping control system


68


(represented schematically by hydraulic manifolds), the gripping jaws


64


come together about the forward and rear edges of a selected tie plate


20


and grasp it under fluid power. Next, the retracting mechanism


66


moves the gripped plate away from the tie


18


. Preferably, the gripped plate is moved to an area


70


between the rails


14


,


16


, however it is contemplated that the plate may be moved to another area away from the movement of the tie


18


as it is being extracted.




It is contemplated that the plate remover assembly


50


is connectable in a fixed position relative to the frame


24


, using welded or otherwise fastened bracket members (not shown) connecting the respective components. However, in the preferred embodiment, the present tie extraction apparatus


10


includes a locating system, generally designated


72


, which controls the movement of the plate remover assembly


50


relative to the frame


24


. The system


72


preferably takes the form of a pair of retractable tethers


74


,


76


, each of which is connected at a hook end


78


to a respective eyelet


80


fixed to each of the front and rear ends


56


,


58


of the remover frame


52


. While the preferred tethers


74


,


76


are belts or straps made of synthetic fabric selected for strength, durability and resistance to stretching, metal cables, chains or other such retractable tether materials are also contemplated.




Opposite the hook ends


78


, each of the tethers


74


,


76


is connected to a respective winch or powered winder


82


(best seen in FIG.


6


and designated


82


F and


82


R) affixed to the tie extractor apparatus


10


, preferably on the frame


24


. Energization of the winch


82


connected to the front tether


74


to retract the tether will pull the plate remover assembly


50


toward the front


40


of the frame


24


, and energization of the winch


82


connected to the rear tether


76


to retract the tether will pull the assembly


50


toward the rear end


42


of the frame


24


. Upon the energization of one of the winches


82


, the control system


30


is configured to exert a braking force on the plate remover assembly


50


to steady its movement relative to the frame


24


.




An important function of the locating system


72


is the positioning of the plate remover assembly


50


at a designated location relative to the frame


24


, and specifically relative to the first and second extending members


44


,


46


. Proper alignment of the plate remover assembly


50


is important so that the plates


20


of a designated tie


18


can be removed in conjunction with the tie extraction. Thus, the locating system


72


is configured for determining the location of the plate remover assembly


50


relative to a reference point corresponding to the tie gripping mechanism


48


and for moving the plate remover assembly to the reference point.




Referring now to

FIGS. 4 and 5

, to achieve this location objective, in the preferred embodiment, at least one of the tethers


74


,


76


is provided with at least two linearly spaced indicators


84


. The exact nature and/or composition of the indicators


84


may vary widely to suit the application, but in function the indicators must be capable of being sensed by at least one sensor unit


86


. In the preferred embodiment, the sensor unit


86


is a proximity switch and the indicators


84


are metallic plates. Since the plates


84


are secured to a nonconductive tether material, the location of the plates on the tether


74


,


76


provides the control system


30


with an indication of the position of the plate remover assembly


50


relative to the tie extraction apparatus


10


. The control system


30


is configured to receive signals from the sensor unit


86


and to perform a counting function to determine how many indicator plates


84


, correspondingly how much of the tether length, and ultimately how much the assembly


50


, has moved relative to the extraction apparatus


10


.




To effect accurate positioning of the remover assembly


50


, the sensor unit


86


is connected through the control system


30


to at least one and preferably both of the winches


82


to retract or extend the respective tethers


74


,


76


as is necessary to properly locate the plate remover assembly. Further, the indicator plates


84


are placed on the tether


74


at a designated spacing which may vary to suit the application, but in the preferred embodiment is 18 inches. In addition, a pair of remover indicators


88


,


90


are provided on the front tether


74


in a location closest to the front


56


of the remover frame


52


. The remover indicators


88


,


90


are preferably of the same construction of the indicators


84


, but are spaced differently. Specifically, the remover indicators


88


,


90


are spaced apart a distance “Q” which corresponds to the spacing of the respective tie extractor extending members


44


,


46


. Further, a pair of sensor units


86


are preferably provided, designated


86


R and


86


L, corresponding to the side (right or left) of the frame


24


at which the tie extraction operation will take place.




Since the extending members


44


,


46


are mounted to the frame


24


in side-by-side relationship to each other, the orientation, or the respective reference point P, of the remover frame


52


for plate gripping and removal will be different depending on which of the extending members


44


,


46


is in use. Referring now to

FIG. 4

, when the extending member


44


is operating (on the left side of the track


12


) once both sensor units


86


R,


86


L are triggered by the corresponding indicator plates


88


,


90


, the control system PLC will recognize that the remover frame


52


has reached the appropriate point P. Thus, the control system


30


will cause the remover frame


52


to move forward until the sensors


86


R,


86


L encounter the remover indicators


88


,


90


, designating that the proper position for removing the tie plates


20


from the tie has been achieved.




Referring now to

FIG. 5

, when the extending member


46


is operating (on the right side of the track


12


), only the sensor


86


L will be triggered by the remover indicator


88


after the control system


30


has moved the remover frame


52


to the adjusted reference point P′. If desired, the sensors


86


L,


86


R may be programmed to be triggered by the indicator


90


. The relative displacement of the sensors


86


L,


86


R reflects the difference in the operational reference point P of the remover frame


52


associated with each of the extending members


44


,


46


.




Referring now to

FIG. 6

, the control system


30


is configured for operating the tie gripping and extraction apparatus


44


,


46


and


48


, as well as the plate remover assembly


50


, and is schematically shown. As will be appreciated by those skilled in the art, as is typical with rail maintenance equipment, the majority of the functions described herein are actuated by fluid power systems, and preferably hydraulic fluid power. It is contemplated that the ordinary skilled practitioner will have sufficient knowledge to implement the functions described herein, which are achieved using commercially available hydraulic components. As such, the underlying hydraulic and, where applicable, related electronic circuitry have not been described in detail.




The control system


30


includes a main control panel


100


located in the cab


28


. Both the tie gripping and pulling mechanism


44


,


46


,


48


(collectively referred to as


102


and the plate removing assembly


50


are connected to the control panel so that the respective functions can be coordinated. From a functional standpoint, it is important to the present invention that the tie gripping and extraction assembly


102


is activated upon the grasping of the tie plates


20


by the plate remover assembly


50


. To increase the efficiency of the rail maintenance operation, it is important to prevent the tie plates from being dragged from the rail bed along with the extracted tie


18


. Thus, the rail tie extraction apparatus


10


is constructed, and the control system


30


is configured to sequentially operate the components


50


,


102


so that once the plates


20


are grasped and displaced from the ties, the operator then manually initiates the ties being pulled from the track


12


.




In addition, as described above, the control system


30


is configured to locate the remover frame


52


relative to the first and second extending members


44


,


46


so that the plates


20


are automatically removed from the correct selected tie


18


. The particular selected extending member


44


,


46


is relevant to the side of the track


12


from which the tie


18


is being extracted.




In the event the remover frame


52


is movable relative to the frame


24


, the remover frame


52


is provided with a pair of hold down cylinders


104


which temporarily stabilize the buggy relative to the track


12


by extending a piston rod


106


onto the plate remover frame to keep it on the rail


16


. A buggy hold down valve


108


is connected to the control panel


100


and to both cylinders


104


for controlling their operation upon commencement of a tie replacement. As is known in the art, it is preferable to include a pressure relief valve


110


in the circuit including the hold down valve


108


, and in this application the valve


110


is set at 550 psi. The precise setting may vary to suit the application.




To bring the remover frame or buggy


52


forward toward the sensor units


86


, the winch


82


F located nearer the front end


40


of the frame


24


is activated. In the preferred embodiment, the winches


82


are hydraulically powered by a hydraulic motor


112


under the control of a forward control valve


114


, which in turn is under the control of the control panel


100


. Since the movement of the remover frame


52


must be precisely controlled, the winch motor


112


is also equipped with a brake


116


to prevent unwanted rotation of the motor, and ultimately, the winch


82


F. A winch brake valve


118


applies the brake


116


when directed to by the control panel


100


, usually upon the desired disposition of the remover frame


52


, as triggered by the sensor unit


86


.




As a further control on the movement of the remover frame


52


, to both hold the frame in place by pressure on the rear tether


76


, and also to move the frame in the reverse direction, the control system


30


generates a reverse biasing force in the form of a separate reverse motor


120


operated by a motor control valve


122


for powering the second winch


82


R. In similar fashion to the forward motor


112


, a reverse winch brake


124


is provided for stopping unwanted rotation of the motor


120


and the winch


82


R. A rear winch brake valve


126


controls the reverse winch brake


124


and is under the control of the control panel


100


. To move the remover frame forward, or to the left in

FIG. 6

, the winch


82


F is energized, which, when turned by the motor


112


pulls on the tether


74


. At the same time, the tether


76


unwinds, which causes the motor


120


to rotate. However, a flow control valve


128


controls the flow of hydraulic fluid to the motor


120


and exerts a resistance force upon the motor, in effect braking the motor so that the winch


82


R does not excessively unwind the tether


76


. Since there is no energizing flow of fluid to the motor


120


, the flow control


128


is configured to naturally create back pressure on


120


and that keeps the tether


76


taught. Thus, the flow control


128


meters flow out of the motor


120


without actually turning the motor on.




As necessary, the reverse winch brake


124


is applied to prevent excessive unwinding of the tether


76


from the rear winch


82


R. The process is reversed when the buggy


52


needs to be moved closer to the rear end


42


of the frame


24


. In that situation, the reverse winch


82


R and its associated motor


120


provides the main motive force, and the appropriate flow control


128


provides the biasing control force.




Also, it is preferred that flow control valves


128


are provided for the circuits pressurizing the winch motors


112


,


120


as well as the hold down cylinders


104


. Also, signal connections


130


between the control panel


100


and the valves


108


,


114


,


118


,


122


and


126


are shown schematically and it is contemplated that the valves may be controlled electronically, hydraulically, individually or in prescribed sequences, depending on the application, as is known in the art. A feature of the present invention is that the plates


20


are released by the gripping jaws


64


of the plate removing assembly


50


as soon as the tie


18


is fully retracted from the track


12


.




In operation, it will be seen that the tie pulling apparatus


10


equipped with the plate removing assembly


50


extracts a tie


18


by first being located at a tie to be removed. The plate removing assembly


50


is then moved toward the selected tie


18


by the control assembly


30


, and the remover frame


52


is accurately located through the operation of the indicators


84


and the sensor units


86


R,


86


L. The tie plates


20


on the selected tie


18


are engaged by the gripping jaws


64


. Next, the rail lifting apparatus


49


is employed to lift either one or both of the rails


14


,


16


on the side of the track from which the tie


18


will be removed. The plates


20


are then detached from the tie and moved away from the tie. As the tie plates


20


are being removed, the extending member


44


,


46


and its associated gripping mechanism


48


grip an end of the tie


18


and pull it transversely from the track


12


. As the tie


18


is pulled away, the plates


20


are released by the gripping jaws


64


and fall to the track between the rails


14


,


16


, or wherever designated.




While specific embodiments of the combined tie extractor and plate remover for rail maintenance of the present invention have 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.



Claims
  • 1. A combined tie extractor and plate remover for maintenance on a railroad track, comprising:a frame configured for movement along the track and having a first side corresponding to a first side of the track and a second side corresponding to a second side of the track, each side of the track having a corresponding rail; a rail lifting apparatus associated with said frame and configured for lifting a selected one of the first and second rails away from the track; a plate remover assembly associated with said frame and configured for grasping and removing tie plates associated with each side of the track from a selected tie; and at least one tie extracting assembly disposed on said frame for extracting the tie transversely relative to the track in conjunction with the removal of the tie plates; wherein said plate remover assembly is movable on the track relative to said frame in a direction parallel to the track.
  • 2. The apparatus of claim 1 further including a control mechanism connected to said plate remover assembly and said at least one tie extracting assembly for activating said at least one tie extracting assembly upon the grasping of the tie plates by said plate remover assembly.
  • 3. The apparatus of claim 1 wherein said at least one extracting assembly further includes gripping means disposed on each of said sides of said frame and configured for grasping rail ties located in the track and extending means attached to said frame, said extending means including a first extending member associated with the first side of the track and a second extending member associated with the second side of the track, said extending members mounted to said frame in a non-axial relationship to each other and configured for positioning said gripping means relative to a selected rail tie located on the corresponding side of the track.
  • 4. A combined tie extractor and plate remover for maintenance on a railroad track, comprising:a frame configured for movement along the track and having a first side corresponding to a first side of the track and a second side corresponding to a second side of the track, each side of the track having a corresponding rail; a rail lifting apparatus associated with said frame and configured for lifting a selected one of the first and second rails away from the track; a plate remover assembly associated with said frame and configured for grasping and removing tie plates associated with each side of the track from a selected tie; at least one tie extracting assembly disposed on said frame for extracting the tie transversely relative to the track in conjunction with the removal of the tie plates; and a locating system for locating said plate remover assembly at the selected tie; wherein said plate remover assembly is movable on the track relative to said frame.
  • 5. The apparatus of claim 4 wherein said locating system is configured for determining the location of said plate remover assembly relative to a reference point corresponding to said at least one extraction assembly, and moves said plate remover to said reference point.
  • 6. The apparatus of claim 5 wherein said locating system includes a tether connecting said plate remover assembly to said frame, a plurality of linearly spaced indicators on said tether, a sensing mechanism for sensing said indicators and generating a location signal of said plate remover assembly which triggers a tether controller for adjusting the length of said tether and accordingly adjusts the position of said plate remover assembly.
  • 7. The apparatus of claim 6 wherein said tether is taken from the group comprising belts, straps, cables and chains.
  • 8. The apparatus of claim 6 wherein said sensing mechanism is configured for determining the distance of said plate remover assembly from said reference point, and for controlling said tether controller for adjusting the position of said plate remover assembly relative to said reference point.
  • 9. The apparatus of claim 8 wherein said at least one tie extracting assembly further includes gripping means disposed on each of said sides of said frame and configured for grasping rail ties located in the track and extending means attached to said frame, said extending means including a first extending member associated with the first side of the track and a second extending member associated with the second side of the track, said extending members mounted to said frame in a non-axial relationship to each other and configured for positioning said gripping means relative to a selected rail tie located on the corresponding side of the track, wherein said sensing mechanism includes first and second proximity switches for establishing said reference point for each of said first and second extending members.
  • 10. The apparatus of claim 6 wherein said tether controller further includes at least one motor for retracting and extending said tether, and a biasing mechanism for exerting a biasing force counter to said at least one motor.
  • 11. A combined tie extractor and plate remover for maintenance of a railroad track, comprising:a frame configured for movement along the track and having a first side corresponding to a first side of the track and a second side corresponding to a second side of the track, each side of the track having a corresponding rail; a rail lifting apparatus associated with said frame for lifting a selected one of the first and second rails away from the track; a plate remover assembly associated with said frame and configured for grasping and removing tie plates associated with each side of the track from a selected tie; a pair of non-axially aligned extending members, each associated with a respective one of said sides of said frame and each being provided with a corresponding gripping and extracting assembly configured for extracting one of the ties of the track adjacent the lifted rail transversely relative to the track once the tie plates have been removed; and a locating system configured for moving said plate remover assembly relative to said extending members, said system having a sensing system configured for creating a first operational reference point for locating said plate remover assembly adjacent a first one of said extending members, and a second operational reference point for locating said plate remover assembly adjacent a second one of said extending members.
  • 12. The apparatus of claim 11 further including a control system configured for selectively activating one of said first and second extending members so that said first extending member pulls ties from a right side of said frame, and said second extending member pulls ties from a left side of said frame, said sensing system includes a first sensor for determining the position of said plate remover assembly relative to said first extending member, and a second sensor for determining the position of said plate remover assembly relative to said second extending member.
  • 13. The apparatus of claim 12 wherein said locating system includes a tether connecting said plate remover assembly to said frame and having a plurality of linearly spaced indicators, and said first and second sensors are configured for determining the position of said plate remover assembly relative to said reference point.
  • 14. The apparatus of claim 13 further including a tether controller having at least one motor for retracting and extending said tether, and a biasing mechanism for exerting a biasing force counter to said at least one motor.
  • 15. The apparatus of claim 13 wherein said tie plate gripping assembly is configured for grasping a selected tie plate, pulling the plate away from the rail and away from the tie, and subsequently releasing the plate.
  • 16. The apparatus of claim 15 wherein said sensing system is configured for controlling said tie plate gripping assembly regarding the location of where the tie plates are released.
  • 17. A method for extracting ties and removing plates from a railroad track having a first and a second rail, comprising:gripping a front edge and a rear edge of both tie plates located upon a tie to be extracted using a tie plate gripping assembly; lifting at least one of the rails of the track at a selected location of a tie extraction; pulling the tie plates away from the tie; grasping an end of the tie to be extracted adjacent the location where the rail is lifted, said grasping being performed by a tie gripping and extraction assembly; pulling the grasped tie transversely relative to said track from the point where the rail was lifted; and releasing said gripped plates.
  • 18. The method of claim 17 wherein said plates are released upon the pulling of the grasped tie away from the track.
  • 19. A method for extracting ties and removing plates from a railroad track having a first and a second rail, comprising:gripping both tie plates located upon a tie to be extracted using a tie plate gripping assembly; lifting at least one of the rails of the track at a selected location of a tie extraction; pulling the tie plates away from the tie; grasping an end of the tie to be extracted adjacent the location where the rail is lifted, said grasping being performed by a tie gripping and extraction assembly; pulling the grasped tie transversely relative to said track from the point where the rail was lifted; and releasing said gripped plates; wherein said tie plate gripping assembly is movable along said track relative to said tie gripping and extraction assembly, and said method includes locating said plate gripping assembly adjacent said tie gripping and extraction assembly after said rail lifting step.
  • 20. The method of claim 19 wherein said tie gripping and extraction assembly includes two non-axial extending members, one associated which each rail of the track, said location of said plate gripping assembly further includes locating said assembly to a first location for operation on a side of the track associated with the first rail, and locating said assembly to a second location for operation on a side of the track associated with the second rail.
RELATED APPLICATIONS

This application is a continuation-in-part of Ser. No. 09/810,975, filed Mar. 16, 2001 now U.S. Pat. No. 6,463,858 entitled RAIL TIE REPLACEMENT METHOD AND APPARATUS and Ser. No. 10/113,585 filed Mar. 29, 2002 entitled PLATE HANDLING SYSTEM, both of which are incorporated herein by reference.

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Continuation in Parts (2)
Number Date Country
Parent 09/810975 Mar 2001 US
Child 10/233922 US
Parent 10/113585 Mar 2002 US
Child 09/810975 US