Railway plate inserter

A railway vehicle for inserting plates on rail ties that engage with rails includes a frame configured for movement relative to the track and a plate inserter workhead mounted to the frame. The plate inserter workhead is configured for pivoting the tie plate about a leading edge of the plate so that the trailing edge of the tie plate is lifted off the tie. The plate inserter workhead is configured to subsequently release the plate.

BACKGROUND OF THE INVENTION

The present invention relates generally to railroad right-of-way installation or maintenance machines, and specifically to a railway plate inserter for applying rail plates to rail ties, and a method of inserting the plates.

Conventional railroad track consists of a plurality of spaced parallel wooden ties to which are 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 or base of the steel rail. Since two rails make up a railroad track, there are 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.

When laying a new railroad track, replacing worn ties, or when laying new rails on a pre-existing railroad track, it is necessary to provide and position tie plates on the railroad ties. One plate is required for each side of each tie. The plates are initially placed adjacent the track, either by a crane or by a work gang. Then, the plates are placed onto the top surface of the tie. Subsequently, the plate must be positioned to the proper location on the tie to receive the rail.

Proper positioning of the plate on the tie requires the work gang to center the plate on the width direction of the tie, and position the plate under the rail to receive the bottom portion of the rail in the recess of the plate. In the past, the work gang has had to lift the rail or the tie in order to properly position the plate. It will be appreciated that the manual placement involves high labor costs, inconsistent accuracy of placement, and a time consuming process.

To avoid on the job injuries, especially those involved with handling tie plates, which typically weigh approximately 18-40 pounds and are awkward to manipulate, railways have attempted to mechanize the plate insertion process as much as possible. Such systems have not been widely accepted by the railroads because of the relatively complicated mechanisms involved in performing the insertion.

Additionally, there is inaccuracy in some of the insertion machines, particularly when there are irregularities in plate sizes and shapes. For example, the plates used on a curve in the track are larger than the plates used on a straight stretch of track. Deviations of as little as ⅜ of an inch in the plate is significant in terms of an insertion machine being able to properly place the plate. Due to these variations, frequent readjustment of settings is required to accommodate different sizes and shapes of plates.

Further, in many instances the insertion of the new plate is impeded by railway ballast. Conventional mechanisms have no way to remove unwanted ballast particles from the top surface of the tie.

Railroad installation and maintenance machines typically include a frame which is either self-propelled or towable along the track, and a plate inserter configured to perform the maintenance task. Such devices typically have a travel position, where the portion of the plate inserter is held sufficiently above the track to avoid damage by obstacles including the track itself, and a work position. During operation in the work position, the units typically move between a loading position for loading the part, and a track engaging position for applying the repair part. To avoid damage to the mechanisms, such units are designed for operation so that either travel is prohibited when these mechanisms are in the latter two positions, or the mechanisms automatically rise to the travel position when the unit begins to move to the next location.

While protecting the plate insertion mechanisms, these conventional operational precautions tend to take time and limit productivity of the plate insertion process. Further, in cases where the plate inserter is one of a chain of maintenance machines, the productivity of the overall maintenance of the railroad 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.

There is also a need for an improved plate inserter which enables a high frequency of plate insertions while protecting the plate inserting mechanisms.

Further, there is a need for an improved plate inserter which is accurate despite variations in the track, and which does not require readjustment to accommodate the variations in the track.

SUMMARY OF THE INVENTION

The above-identified objects are met or exceeded by the present railway vehicle for inserting plates on rail ties that engage with rails. The railway vehicle includes a frame configured for movement relative to the track. Mounted on the frame is a plate inserter workhead configured for pivoting the tie plate about a leading edge so that a trailing edge of the tie plate is lifted off the tie. The plate inserter workhead is also configured for subsequently releasing the plate.

More specifically, the present invention provides a railway vehicle for inserting tie plates located on rail ties that engage with rails, each tie plate having a field side shoulder. The railway vehicle includes a frame configured for movement relative to the track. Mounted on the frame is a plate inserter workhead configured for engaging the field side shoulder and pushing the plate along the rail tie. The plate inserter workhead is also configured for subsequently releasing the plate.

In a preferred embodiment, a railway vehicle for inserting plates located on rail ties that engage with rails includes a frame configured for movement relative to the track. The plate inserter workhead is mounted on the frame and is configured for engaging a field side shoulder of the plate with a base of the rail. The plate inserter workhead is also configured for subsequently releasing the plate.

A preferred method for inserting tie plates on railroad ties on a railroad track having a pair of rails includes pivoting the tie plate in a direction towards the rail and about a leading edge of the tie plate. The method also includes engaging the tie plate with the base of the rail and releasing the tie plate to allow it to fall upon the track with the rail engaged on the tie plate.

A plate pusher in a plate pusher assembly having a pushing arm is provided. The plate pusher includes a first portion having an attachment formation for linking the plate pusher to the plate pusher arm, and at least one contact body attached to or integral with the first portion. The contact body extends generally transverse to the first portion in the vertical direction. Also included is a distal end on the contact body which is offset in the vertical direction from the attachment formation. The distal end has an engaging formation configured to engage the plate.

A stop pin assembly for opposing the motion of a plate on a tie in a plate inserter is provided. The stop pin assembly includes an elongate member having a first end operatively attached to the plate inserter workhead, and a distal end opposite of the first end. The distal end has a tip attached to and extending therefrom, the tip being configured to engage the tie. At least one attachment structure is disposed on the elongate member and is configured for receiving a corresponding attachment structure of a locator tool to attach the locator tool to the stop pin.

A preferred locator tool for attachment to stop pins in a plate inserter workhead is provided. The locator tool includes an extension portion extending between at least two stop pins. The extension portion includes at least one attachment structure configured to engage a corresponding attachment structure on the stop pins. Also included is a receiving portion, which is attached to or integral with the extension portion. The receiving portion includes a receiving formation configured to receive a leading edge of a plate and to permit the leading edge to pivot within the receiving formation.

The present centering finger assembly on a plate centering workhead for centering a tie plate on a tie in a plate inserter includes a plate centering housing. The housing has two opposing sides generally corresponding to the width of the tie plate. There is at least one centering finger on each of the two opposing sides of the plate centering housing. The centering finger has a first end disposed on the plate centering housing, a distal end disposed opposite of the first end, and a body located between the first and second ends. The body has a spring bias toward the opposite centering finger. The spring bias is configured to maintain the plate centered on the tie as the plate is moved along a top surface of the tie and between the opposing centering fingers.

A preferred workhead-centering mechanism on a plate inserter workhead for centering the workhead above a tie is provided. The workhead-centering mechanism includes at least two tie gripper arms configured for controlled reciprocation in a direction parallel to a rail and towards the tie. A first tie gripper arm is disposed adjacent a first side surface of the tie, and a second tie gripper arm is disposed adjacent a second side surface of the tie. At least one rod is disposed between the tie gripper arms and located above the tie. Also included is at least one cylinder for converging the tie gripper arms along the rod and engaging on the first and second side surfaces of the tie to center the plate inserter workhead between the tie gripper arms.

A rail locator on a plate-stopping mechanism of a plate inserter workhead is provided. The rail locator includes a first portion having an attachment formation for linking the rail locator to the plate-stopping mechanism. At least one contact body is attached to or integral with the first portion. The contact body extends generally perpendicular to the first portion in the horizontal direction. A recess is located in the contact body at a lower surface. The lower surface is configured to engage a side surface of a rail, and the recess is configured to accommodate a plurality of rail ball shapes.

A preferred tie gripper arm assembly on a workhead-centering mechanism of a plate inserter workhead is provided. The workhead-centering mechanism is configured to reciprocate the tie gripper arm assembly in a direction parallel to the rail. The tie gripper arm assembly includes at least one tie gripper arm extending in a first direction, and a second portion attached to the tie gripper arm and generally perpendicular to the tie gripper arm. Also included is a bolt mount portion attached to at least one of the second portion and the tie gripper arm. The bolt mount portion has at least one attachment formation configured to be attached to the workhead-centering mechanism for reciprocating the tie gripper arm assembly parallel to the rail.

DETAILED DESCRIPTION OF THE INVENTION

Referring now toFIGS. 1-2, a railroad plate inserter workhead is generally designated10, and is specifically disposed on a railway maintenance vehicle, generally designated12, and designed for use in inserting tie plates14onto the railroad track, generally designated16. The track16is made up of a pair of spaced rails18, which are secured to a plurality of spaced, parallel ties20by the tie plates14. As is well known, the ties20are typically wood, but are also made of concrete in some applications. The present application is concerned with track16laid upon wooden ties20, which periodically need replacement due to natural deterioration.

As is known in the art, the tie plates14are secured to the ties20by spikes22or threaded fasteners, here collectively referred to as spikes. Only a few spikes22are depicted inFIGS. 1-2since at that stage of the rail installation or maintenance operation, all of the spikes would be withdrawn from tie plates about to be removed or just inserted. The present railway maintenance vehicle12and/or system is designed as a self-propelled unit independently movable along the track16, having an operator's control station24and a power source (not shown) as is known in the art, or alternatively, may be designed for use in a self-propelled or a towed configuration in conjunction with a chain of railway vehicles.

The present railway vehicle12includes a minor frame26configured for movement relative to the track16and provided with a pair of generally parallel side members28and a pair of end members30, which are connected at respective corners32to form a generally square or rectangular frame shape. The operator's control station24is preferably located on the minor frame26.

For purposes of describing the present railway vehicle12, the forward direction is in the direction of travel and the rearward direction is opposite the direction of travel. The vertical direction is transverse to the direction of the track16, and the horizontal direction is parallel to the direction of the track.

Extending in the forward direction from the minor frame26(as defined by the direction of travel), is a major frame34. The major frame34supports the plate inserter workhead10and a rail lifter workhead36, and extends to a front end38of the vehicle12. Preferably, there is one plate inserter workhead10on each side of the frame34to accommodate each rail18. Further, each plate inserter workhead10can be triggered to operate together or independently of each other.

Preferably, the major frame34extends centrally and generally longitudinally along the length of the railway vehicle12, however other arrangements are contemplated as long as structural support for the components is provided. Rail wheels40are rotatably mounted near the front end38and at the minor frame26to make the vehicle12movable along the track16. Although other locations of rail wheels40are contemplated, the wheels are preferably spaced from both the rail lifter workhead36and the plate inserter workhead10.

The rail lifter workhead36is preferably positioned rearward from the first set of wheels40, and forward of the plate inserter workhead10. The rail lifter workhead36preferably has clamps42to engage the rail18and is configured to hydraulically lift the rail18off of the tie20and off of the plate14, as is known in the art. When the rail18is lifted, a gap is created between the rail and the tie20for the replacement, and a new plate14can be inserted between the rail and the tie.

A flowchart of the preferred process steps of the railway vehicle having a rail inserter10is shown inFIG. 5. While the flowchart outlines the preferred process, it should be understood that the order of the steps can be varied, and variations to the steps are contemplated. The preferred process will be described herein.

Referring now toFIGS. 1-5, a control system44is used by the operator to spot or position the maintenance vehicle12and the plate inserter workhead10(step A ofFIG. 5). The operator controls the movement of the vehicle12over the track16until the target tie20to which a plate14is to be inserted is located. The plate inserter workhead10is lowered by virtue of a main cylinder46(step C ofFIG. 5). The plate inserter workhead10includes a locating mechanism48, a plate-stopping mechanism50, and a plate pushing assembly52. The locating mechanism48further includes the mechanisms to first center the plate inserter workhead10above the tie20, and second, to center the plate14on the tie. A more detailed description of the movement of each component of the plate inserter workhead10will be described later.

The control system44is used for controlling the workhead centering, the plate centering and the plate pushing operations. Included in the control system44is a hydraulic manifold (not shown) which receives the fluid power (preferably hydraulic) from lines which are connected to the various cylinders. The manifold is also connected to a plurality of hydraulic control valves (not shown) which, with the hydraulic lines and the cylinders, form a hydraulic circuit as is well known in the art. While actuation of the various mechanisms is preferably accomplished with hydraulic cylinders, it is contemplated that any type of actuation can be used.

The operator preferably triggers the control system44by a button or switch54on an operator-manipulated control device56, preferably a joystick, however other equivalent control units are contemplated. By manipulating the button or switch54, the operator controls the movement of the locating mechanism48and the plate-stopping mechanism50(step B ofFIG. 5). It will be appreciated that once the plate insertion cycle is initiated, some of the calculations and hydraulically controlled tasks are performed automatically, as is well known in the art.

In operation, the plate inserter workhead10moves along the track16on the vehicle12until the operator locates a tie20needing a plate14inserted. The various moving components are in their rest or inactive positions. Using the control device56, the plate inserter workhead10is positioned relative to the tie20in question so that the tie is located between tie gripping arms58of the locating mechanism48. However, the specific position of the locating mechanism48relative to the subject tie20may vary slightly with each gripping cycle. Referring now toFIG. 3A, once the locating mechanism48is in position, the operator actuates the switch or button54to initiate the automatic sequence described below.

Referring now toFIG. 3B, the locating mechanism48is lowered by the main cylinder46along a frame member47to the tie20. The locating mechanism48includes a workhead-centering mechanism142for centering the plate inserter workhead10above the tie20. The locating mechanism48preferably includes a vibrator60that aids the workhead-centering mechanism142in penetrating through ballast on both sides of the tie20. At least one tie gripper arm58extends from a tie gripper support frame64that engages a first and a second rod66,68running generally parallel to the rail18. Preferably, the tie gripper arm58is the portion of the workhead-centering mechanism142that penetrates the ballast. A second tie gripper support frame65is located inside the support frame64and also engages the first and second rod66,68.

Preferably, there are at least two tie gripper arms58which move toward each other as they slide along the first and second rods66,68(step D ofFIG. 5). In the preferred embodiment, there are eight gripper arms58spaced along the locating mechanism48, and specifically, there are preferably four gripper arms58configured to be located on each side of the tie20. As the tie gripper arms58move towards each other, they converge on side surfaces70of the tie20. A tie grip cylinder72provides hydraulic pressure to slide the support frame64along the first and second rods66,68to converge the tie gripper arms58.

Depending on the relative location of the locating mechanism48to the tie20, one or more tie gripper arms58may converge on and engage the side surface70of the tie and the plate14before other tie gripper arms. InFIG. 3C, the left side tie gripper arms58engage the tie20and the plate14, while the right side gripper arms continue to move toward the tie and the plate. Eventually, both sides of the tie gripper arms58will converge on the tie20. When the tie gripper arms have converged on the tie20, the plate inserter workhead10is preferably centered above the tie. In operation, this procedure is performed quickly, preferably within seconds.

At the inner portion of the locating mechanism48is a plate-centering mechanism74that is movable parallel to the direction of the rail18and within an area bounded by a collar76disposed around rods66,68. With this construction, the plate-centering mechanism74is positionable with respect to a plate centering housing78and over the top surface62of the tie20. The plate-centering mechanism74is positioned over the top surface62of the tie20by a contact point80on the tie gripper arm58. As the tie gripper arms58converge towards the tie20, the contact point80engages the plate-centering mechanism74and takes up any misalignment until the plate-centering mechanism and the tie gripper arms are centered above the tie.

At least one, but preferably multiple centering fingers82(FIG. 3A) are disposed on the plate-centering mechanism74of the locating mechanism48. The centering fingers82are spring-loaded and shaped to capture the plate14within the plate-centering mechanism74as the centering fingers descend towards the tie20, and as the tie gripper arms58converge towards the side surfaces70of the tie20. In this configuration, the spring-loaded centering fingers82take up misalignment of the plate14on the tie20as the plate is pushed along the tie. When both sides of the tie gripper arms58engage the tie20, the plate-centering mechanism74of the locating mechanism48should be centered above the plate14, and the plate should be centered on the tie.

Referring now toFIGS. 4A-4F, preferably simultaneously with the descending of the locating mechanism48, the control system44causes the plate-stopping mechanism50to descend. InFIG. 4A, the plate inserter workhead10is in the ready position above the tie20, and inFIG. 4B, the plate inserter workhead is descended to the tie.

InFIG. 4B, the plate-stopping mechanism50descends until a plate stop housing84engages the rail18. When the plate stop housing84impacts the rail18, stop pins86, located at the gage side GG of the rail and operatively connected to the plate stop housing84, should also impact the tie, either at the same time or very close in time. A rail locator90is disposed adjacent the bottom edge of the plate stop housing84, and is movable parallel to the tie20.

Referring now toFIGS. 4E,16and17, the rail locator90includes a first portion95having an attachment formation97A for linking the rail locator to a corresponding attachment formation97B on the plate-stopping mechanism50. In the preferred embodiment, a pin99fastens the attachment formations97A and97B together.

Extending generally perpendicularly in the horizontal direction from the first portion95is at least one, and preferably two contact bodies101. The contact bodies101are preferably integral with the first portion95, but can also be attached to the first portion. A recess96is located in the contact body101at a lower surface85of the contact body. The lower surface85is configured to engage a side surface of the rail ball92(step H ofFIG. 5). The recess96is configured to accommodate a plurality of rail ball92shapes and sizes since rails can be provided in different shapes and sizes, and further, the rail material can flow from repeated use, causing the rail ball to become misshapen. In the preferred embodiment, the rail locator90is provided with an abrasion-resistant coating, such as by flame spraying a metal particulate. As seen inFIG. 4E, a secondary rail locator surface93is preferably provided at the bottom edge of the plate stop housing84. The secondary rail locator surface93is configured to engage a top surface106of the rail ball92. Together, the secondary rail locator surface93and the lower surface85of the contact body cooperate to positively locate the rail ball92with respect to the plate inserter workhead10.

A stop pin assembly88(best seen inFIGS. 4E and 6), which operatively connects the stop pins86to the plate stop housing84, is moved along the top surface62of the tie20toward the gage side GG of the rail14. The motion of the stop pins86may be dependent or independent of the motion of the rail locator90. At least one, but preferably a plurality of stop pins86on the stop pin assembly88move vertically with respect to the plate stop housing84, and move horizontally along the length of the plate stop housing (as will be discussed in greater detail later). The stop pins86move towards the rail18along the length of the tie20until they are a measured distance from the rail (step N ofFIG. 5).

As discussed with respect to the locating mechanism48, the plate pusher assembly52descends until the locating mechanism impacts the tie20or the tie plates14. Since the plate-stopping mechanism50descends until it impacts the rail18, and the locating mechanism48descends until it impacts the tie20or tie plate14, the two workheads are movable with respect to each other. The plate centering housing78is slidable relative to the plate stop housing84by virtue of a relative plate stop rod98, cuff100and slide block102arrangement on opposing surfaces of the plate stop housing and plate centering housing. Specifically, if the plate-stopping mechanism50engages the rail18first, the locating mechanism48will continue to descend, its cuffs100A sliding down the plate stop rod98, and the cuffs100B of the plate stop housing84sliding along the slide block102. In this way, the locating mechanism48and the plate pusher assembly52continue to descend until the locating mechanism impacts the tie20or the tie plates14.

At this point, the gap distance between the rail18and the tie20is measured by the linear variable displacement transducer (“LVDT”), or any other known measuring device104(steps E-H ofFIG. 5). From this measurement, various calculations can be made. For example, the locating mechanism48lift distance, the tie20lift distance, and the rail18lift distance, if required. If the distance is less than a predetermined value or range of values, the rail18is lifted (steps G, J). If the distance is greater than a predetermined value or range of values, the tie20is lifted toward the rail18(steps E, F, I, M, L). Both operational sequences will be described below.

Through the use of an operator controlled potentiometer (not shown) located in the operator's control station24, the predetermined gap distance is set. It is desirable to have about a 2-inch gap between the rail and the tie. The operator dials in an amount, preferably once per day. In the preferred embodiment, the threshold value or range of values is about 1-2 inches, however this value or range of values will vary depending on track type and condition.

The gap distance is calculated using the height of the rail18(manually measured by the operator), which is subtracted from the total vertical distance of the bottom surface94of rail locator90from the tie20. The total vertical distance of the bottom surface94from the rail18is measured by the LVDT104. In the preferred embodiment, the LVDT104is located on the plate-stopping mechanism50. Assuming the gap distance is below the threshold range, the rail18will be lifted by the rail lifter workhead36provided on the major frame34until the predetermined gap distance is attained (steps G, J). Assuming the gap distance is above the threshold value, the tie gripper arms58will lift the tie20until the predetermined gap distance is attained steps E, F, I, M, L). If the gap distance is within the threshold range, neither the tie20nor the rail18will be lifted.

When the rail18is lifted by the rail lifter workhead36to obtain the predetermined gap between the rail and the tie20, the rail in turn lifts the plate-stopping mechanism50. The plate-stopping mechanism50is raised with the rail18because the plate stop housing84engages the rail at an upper surface106of the rail, so when the rail is lifted, the plate-stopping mechanism50is lifted with it. However, the stop pins86do not ascend with the plate-stopping mechanism50, but preferably remain engaged on the tie20(step M ofFIG. 5).

The plate14is positioned under the rail18by a plate pusher108sliding the plate along the tie20, and pivoting the plate about a leading edge110of the plate (steps K, O, P, Q ofFIG. 5). In the preferred embodiment, the plate pusher108positions the plate14in two stokes. The first stroke pushes the plate14along the tie20(step K, O ofFIG. 5), and the second stroke pivots the plate into engagement with a lower portion112of the rail (step P, Q ofFIG. 5).

Before the initial stroke, the locating mechanism48lifts off the tie20to provide the pusher assembly52with additional space to cycle, however, other configurations are contemplated. When the locating mechanism48ascends off the tie20, the cuffs100A slide up the plate stop rod98, while the plate-stopping mechanism50preferably does not move.

As seen inFIGS. 4C-4Dand11, the plate pusher108preferably includes an engaging formation114which is configured to engage the plate14. The motion of the plate pusher108is generally along the bottom of the locating mechanism48. A pusher arm116and a main pusher cylinder118are preferably located to the field-side FD of the locating mechanism48. The extension of the main pusher cylinder118causes the dog-leg shaped pusher arm116to place the plate pusher108in engagement with a field-side shoulder120of the plate14.

Referring now toFIG. 18, the plate pusher108has a first portion113including an attachment formation115for linking the plate pusher to a plate pusher arm117. At least one contact body109is attached to or is integral with the first portion113, and the contact body extends generally transverse to the first portion in the vertical direction. A distal end156on the contact body109is offset in the vertical direction from the attachment formation115. The distal end156includes the engaging formation114configured to engage the plate. By extending, the main pusher cylinder118causes the plate pusher108to pivot about a pivot point122to push the plate14along the surface62of the tie20until it is as close as possible to the rail base, or in the alternative (if the rail is sufficiently raised above the tie), until the end of the pusher assembly52stroke or until the plate14engages the stop pins86(SeeFIG. 4B). The length of the stroke of the plate pusher108is predetermined through the dimensions of the pusher arm116and the length of the cylinder arms118,132.

During the initial stroke, as the plate14is pushed across the tie20, the locating mechanism48, through its plurality of spring-biased centering fingers82, centers the plate14on the tie20, since the plate-centering mechanism74of the locating mechanism is pivotable on the plate centering housing78. In the preferred embodiment, the pusher arm116performs the initial stroke until a timer times out the stroke. When the stroke is timed out, the pusher arm116retracts (FIG. 4C) (Step O ofFIG. 5).

The lifting of the rail18or the tie20depending on the measured gap, as explained above, preferably occurs before the first stroke of the plate pusher108, but alternatively, can occur between the first stroke and the second stroke. The dimensions of the pusher arm116and the extensions of the cylinder arms118,132dictate the geometry of the stroke and whether lifting is desirable before or after the first stroke. Whichever order the lifting occurs, it is important for the predetermined gap to be established between the rail18and the tie20before the second stroke because the plate14must be positioned between the plate and the tie during the second stroke.

As seen inFIG. 4D, upon retracting the plate pusher108from the first stroke, the plate pusher performs a second stroke (Step P ofFIG. 5). This time, the plate pusher108engages a trailing edge126of the plate14. As the plate14is pushed under the rail18, the leading edge110of the plate impacts the stop pins86which are positioned near the gage side of the rail. The vibrators60can be energized to help the pushing motion of the plate14along the tie20(step R ofFIG. 5). A continued pushing stroke from the pusher arm116, working against the pressure of at least one stop pin cylinder130, causes the plate14to elevate at the trailing edge126.

In the preferred embodiment, this elevation is assisted by the vertical elevation of the pusher arm116caused by the supplemental pusher cylinder132retracting. It is also preferred that pressure to the stop pins86is cut off at this point, and the residual pressure and friction in the stop pin system provides sufficient resistance to the pusher arm116to cause the desired elevation (step S ofFIG. 5). Under the pressure exerted from the pusher arm116, the stop pins86retract away from the rail18along the length of the tie20.

As the plate14is elevated, the pusher arm116continues its second stroke and moves the elevated plate closer to the rail14. Eventually, the inside edge of the field side shoulder120, (or the inside of the rail base channel) is placed in contact with the lower portion112of the rail18(FIG. 4E). In this manner, proper alignment is achieved between the rail18and the tie plate14regardless of the size and shape of the tie plate channel.

In prior art plate inserters, a variation in the size of the plate length can cause the rail18and the plate14to not engage. Plates14can vary in size and shape on a track16, particularly at curves in the track. When variation in the plates14occurs, the prior art inserters required that the stop pins86be readjusted. Thus, by engaging a bottom portion of the rail directly into the plate channel, a problem of prior plate placing devices has been overcome without having to readjust the stop pins86.

Once the plate14is engaged on the rail base, the operator notes the engagement and releases pressure on the system by manipulating the switch54(steps Q, T, U ofFIG. 5). Alternately, the pressure can be released by action of a pressure sensor connected to the pusher arm main cylinder118, a timer, or other mechanisms known in the art. The plate pusher108retracts and the plate14is placed onto the tie20at the location of engagement with the rail18. Additionally, upon release of the pressure, the rail lifter workhead36releases the rail18onto the plate14, so that it assumes its prior position, now engaged upon the newly inserted plate.

Preferably, both the plate-stopping mechanism50and the locating mechanism48ascend and resume their rest position. The plate pusher assembly52is also drawn back towards the field side into its initial position. When the plate-stopping mechanism50, the locating mechanism48and the plate pushing assembly52are sufficiently retracted, the operator can move the vehicle12to the next tie20(step V ofFIG. 5).

In the situation where the measured distance is greater than the threshold value or range of values, this signifies that the tie20is lower than desired and must be pulled upward towards the rail18to place the plate14. Ties20often are unusually low in the ballast due to factors involved in the tie insertion process, well known to skilled practitioners.

After the control system44makes the calculation, upon the engagement of the plate-stopping mechanism50and the locating mechanism48with the rail18and the tie20, respectively, the tie gripper58arms engage the tie. The main cylinder46is retracted to raise the tie gripper arms58and the tie20until the LVDT or other measuring device104indicates that the appropriate height has been achieved. When the appropriate height has been achieved, the appropriate predetermined gap exists between the tie20and the rail18. Then the first stroke is initiated by the pusher arm116, as in the first example. At the end of the stroke14, the plate is in close proximity to the rail base, which is raised above the tie20.

According to the preprogrammed cycle, the pusher arm116begins its second stroke, pushing the plate14against the stop pins86. Continued extension of the pusher arm116against the stop pins86moves the pins backwards, but also causes the plate14to elevate at the trailing edge126, as in the first example. Further movement of the pusher arm116places the field side plate shoulder120in engagement with the rail base as described above. In both examples, the pushing assembly52both pushes and pivots the plate14against the backpressure of the stop pins86.

In the event the operator tries to move the vehicle12during the operational cycle, the system is configured to release all pressure to prevent damage to the mechanisms. Further, in the event the vehicle12encounters an obstacle on the track16, shear pins136are located on the plate inserter workhead10to permit the workheads48,50to shear off at a calculated location to minimize damage (SeeFIGS. 3A and 9).

Referring now toFIGS. 6 and 7, the stop pin assembly88will be described in more detail. The stop pin assembly88preferably includes at least two of the stop pins86and a bridging bracket138, and a locator tool140. The bracket138extends between the two stop pins86and is preferably spring loaded so that if one pin hits the tie20and the other does not, the non-contacting pin will not be drastically out of alignment with the other. It is important that the pins86be generally aligned because the alignment of the plate14is determined by the alignment of the pins.

The stop pin86includes an elongate member79having a first end81operatively attached to the plate inserter workhead10, and a distal end83opposite of the first end. Each stop pin86preferably has a tip87which has a first end89that is attached to the distal end83of the stop pin86, and a second end91that engages the tie20. Each stop pin86includes at least one attachment structure77A disposed on the elongate member79configured for receiving a corresponding attachment structure77B of a locator tool140(FIG. 13). In the preferred embodiment, the attachment structure77A is a hole configured to receive a fastener.

As seen in FIGS.7and13-15, the locator tool140preferably includes an extension portion143extending between the stop pins86. The extension portion143preferably includes the least one attachment structure77B which is configured to engage the corresponding attachment structure77A on the stop pins86. The locator tool140also includes a receiving portion145, which is preferably either attached to or integral with the extension portion143. The receiving portion145includes a receiving formation141configured to receive a leading edge110of a plate14and to permit the leading edge to pivot within the receiving formation (FIG. 4B). While the receiving formation141is preferably an indentation in the face of the locating tool140, other configurations of receiving formation are contemplated. Further, other configurations of locator tools140configured to be attached to the stop pins86are also contemplated.

The stop pins86are controlled by multiple cylinders. The main cylinder46controls the vertical movement of the plate-stopping mechanism50as the stop pins86descend until they contact the tie20. The stop pin cylinder130prevents or permits the movement of the stop pins86relative to the rail locator90in the horizontal direction when the plate14is inserted. In the preferred embodiment, a third cylinder129is located generally parallel to and in opposing orientation to the stop pin cylinder130. Together, the third cylinder129and the stop pin cylinder130position the stop pin assembly88near the rail14. Preferably, the stop pin cylinder130and the third cylinder129cooperate to engage the recess96of the rail locator90with the side surface of the rail ball, and to engage the bottom edge94of the rail locator with the top surface of the rail ball. However, the number and arrangements of cylinders can vary. An upper portion131of the stop pins86works in conjunction with the LVDT104(or other measuring device) to measure the gap distance between the rail18and the tie20by measuring the distance between the tie and the bottom contacting surface94of the rail locator90, and subtracting the known height of the rail.

The workhead-centering mechanism142of the locating mechanism48is shown inFIGS. 8 and 9, and a tie gripper arm assembly57is shown inFIG. 12. The tie gripper arms58preferably have a gripping formation144disposed on a distal end146of each arm for gripping the tie20. In the preferred embodiment, the gripping formation144are a series of ridges, but other configurations are contemplated.

The tie gripper arms58are attached to the first and second rods66,68by a gripper mount assembly148. A bolt mount portion150attaches the gripper arms58to support frames65. The support frames65move closer or further away from each other with the retraction or extension of the tie grip cylinder72, respectively. Referring now toFIG. 12, the tie gripper arm assembly57includes the at least one tie gripper arm58extending in a first direction, generally vertically. A second portion147is attached to the tie gripper arm58and is generally perpendicular to the tie gripper arm. Preferably, the second portion147is a structural member that attaches a plurality of tie gripper arms58together. The bolt mount portion150is attached to either the second portion147or the tie gripper arms58, or both. The bolt mount portion150has at least one attachment formation149configured to be attached to the workhead-centering mechanism48for reciprocating the tie gripper arm assembly57parallel to the rail14. InFIGS. 10 and 11, the plate-centering mechanism74of the locating mechanism48is shown. The plate-centering mechanism74is mounted inside the workhead centering portion142of the locating mechanism48, as seen inFIG. 4. Additionally, the plate pusher assembly52is shown inFIG. 11, portions shown in phantom.

As seen inFIGS. 4C,11and18, the plate pusher108has a first portion154linked to the pusher arm116. The first portion154is preferably directly coupled to the second pusher arm117, which is pivotally connected to the pusher arm116at pivot119. Extending between the pusher arm116and the pusher arm117is the supplemental pusher arm cylinder132. The extension of the supplemental pusher arm cylinder132increases the angle between the pusher arm116and the second pusher arm117.

The distal end156of the plate pusher108is preferably offset in the vertical direction from a proximal end154. The contact body109includes and is located between the distal end154and the proximal end156and is sized and shaped to offset the distal end156from the proximal end154to permit the engaging formation114to extend near the tie20, while the remainder of the pusher assembly52is located a distance above the tie.

The distal end156is configured to engage the plate and includes the engaging formation114, which is preferably an indentation158and two protrusions160. As seen inFIG. 4B, the lower protrusion160can engage the field side shoulder120and push the plate along the tie20, and as seen inFIG. 4D, the indentation158can catch and grip the plate14between the protrusions160. Further, the shape of the distal end156permits the plate14to freely pivot while being grasped by the plate pusher108. The pivoting motion of the plate14about the leading edge110results in some motion of the trailing edge126within the indentation158.

The plate pusher assembly52is attached to the locating mechanism48at an upper cylinder attachment162and the pivot point122. The plate pusher assembly52moves relative to the locating mechanism48, the movement being dictated by the number, size, shape, attachment and linkages on the assembly.

While the preferred embodiment of plate pusher assembly52includes a two-bar, two-cylinder linkage with a single pivot point on the locating mechanism48, other configurations are contemplated. Further, there can be one or more plate pushers108associated with the plate pusher assembly52, or one or more plate pusher assemblies associated with the locating mechanism. Further still, the plate pusher assembly can operate independently of any other workhead.

In the preferred embodiment, the centering fingers82are located on the plate-centering mechanism74of the locating mechanism48in a spaced arrangement. Preferably, there are a plurality of centering fingers82and a plurality of tie grippers58on the workhead centering mechanism142of the locating mechanism48. In this preferred embodiment, the spacing along the locating mechanism48is such that the centering fingers82are disposed alternately between the tie grippers58.

While the centering fingers82do not center the plate14on the tie20in the first instance, the centering fingers82retain the plate14centered on the tie20while the plate pusher108slides the plate along the tie. The centering fingers82extend generally downward and outward from a bottom surface164of the plate-centering mechanism74. The fingers82have a generally flat bottom surface166to engage the tie20.

It will be appreciated that the present rail plate inserter workhead10features the ability to accurately place plates14on the tie20. The rate of plate insertion accomplished by the present plate inserter workhead10is in the range of about 5-12 plates per minute, and overall, is as efficient or slightly more efficient than using manual labor for plate insertion, when issues of worker fatigue and manpower costs are eliminated. Also, the above-described drawbacks of conventional automatic plate insertion devices have been overcome.

While specific embodiments of the present railway vehicle having a plate inserter workhead have been shown and described, and specific embodiments of various workheads, mechanisms, and assemblies 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.