Railway track switch

A railroad switch point having fixed rails and switching rails is provided. The switch point includes a first railroad tie having a top side. The switch point also includes a rod positioned at the top side of the first railroad tie. The rod is coupled to the switching rails and is also coupled to a switch actuator. A first rail support is secured to the top side of the first railroad tie for supporting the fixed rails and the switching rails above the rod.

TECHNICAL

The present invention relates generally to railway track equipment. More particularly, the present invention relates to railway track switches.

BACKGROUND

Conventional railroad tracks include rails supported on railroad ties. The railroad ties are supported on an aggregate bed that functions as a foundation for the ties. Routine track maintenance involves the periodic tamping of the aggregate bed to ensure that the bed is sufficiently compacted to provide adequate support to the rails and ties. Tamping is a fairly straightforward procedure on most lengths of track. However, at switch points, tamping can be more difficult because the various switching linkages typically positioned between the rails prevent the tamping equipment from accessing the aggregate bed located beneath the linkages. To overcome the above problem, it has been proposed to place a track switching mechanism within a hollow railroad tie (see U.S. Pat. No. 4,105,175 to De Spiegeleer). However, this type of design is fairly complicated and the relatively large, open volume within the railroad tie provides areas where ice and debris can collect thereby interfering with the effective operation of the switching arrangement. In view of the above problems, an improved switching device for railroad tracks is needed.

SUMMARY

One aspect of the present disclosure relates to a railroad track switching device that is relatively simple and that allows the aggregate adjacent to the switch point to be readily tamped with minimal interference from the switching device.

Examples representative of a variety of inventive aspects are set forth in the description that follows. The inventive aspects relate to individual features as well as combinations of features. It is to be understood that both the forgoing general description and the following detailed description merely provide examples of how the inventive aspects may be put into practice, and are not intended to limit the broad spirit and scope of the inventive aspects.

DETAILED DESCRIPTION

In general, one aspect of the present disclosure relates to a railroad switch having one or more switching linkages mounted within a plate positioned at the top side of a railroad tie. In certain embodiments, the plate can define a channel or other type of guide structure for guiding the linkage along a path of travel (e.g., a linear path of travel). Another general aspect of the present disclosure relates to a railroad track switching device having a switch linkage including a non-electrically conductive composition. In one embodiment, the entire linkage is made of a dielectric material such as plastic. In other embodiments, the linkage can have a composite structure. For example, the linkage may include a conductive (e.g., metal such as steel) core surrounded by a dielectric layer (e.g., a dielectric housing or coating).

FIGS. 1A and 1Bshow a railroad track arrangement20in accordance with the principles of the present disclosure. The track arrangement20includes a main track22and a side track24. The main track22includes a fixed rail22aand a switch rail22b, and the side track24includes a fixed rail24aand a switch rail24b. A switching mechanism26is located at a switch point of the track arrangement20. The switching mechanism26moves the switching rails22b,24bbetween a first position (shown atFIG. 1A) and a second position (shown atFIG. 1B). In the position ofFIG. 1A, the switch point routes trains along the main track22. In the position ofFIG. 1B, the switch point routes trains along the side track24.

Referring still toFIGS. 1A and 1B, the rails22a,22b,24aand24bare supported on railroad ties28. For clarity, only a few of the ties28are shown. The railroad ties28are typically supported on an aggregate base. Typically, the railroad ties28have a wood construction. In one embodiment, the railroad ties28have a square 9 inch by 9 inch cross-sectional shape at the region beneath the rails22a,22b,24a,24b.

Referring toFIG. 2, the switching mechanism26includes an actuator30offset to the side of the fixed rail24a.

Referring still toFIG. 2, the actuator30interfaces with a throw rod32, a lock rod34, and an indication rod36. The actuator30also interfaces with a controller38that controls operation of the actuator30. The actuator30pushes the throw rod32in a direction away from the actuator30to move the switching rails22b,24bfrom the position ofFIG. 1Ato the position ofFIG. 1B. The actuator30pulls the throw rod32toward the actuator30to move the switching rails22b,24afrom the position ofFIG. 1Bto the position ofFIG. 1A. After the switching rails22b,24bhave been moved to the desired position, the actuator30locks the lock rod34in place to prevent unintended movement of the switching rails22b,24b. Prior to switching, the actuator30releases the lock rod34so that the lock rod does not interfere with the movement of the switching rail22b,24bduring switching operations. The indication rod36follows the movement of the switching rails22b,24band interface with electric switches (e.g., limit switches) that provide information to the signal system regarding the position of the switching rails22b,24bso that the position of the switching rails22b,24bcan be verified and monitored.

Referring still toFIG. 2, the actuator30is mounted on railroad ties28a,28b. The railroad ties28a,28bare customized with each having a rail supporting portion40positioned beneath the rails and an actuator mounting portion42on which the actuator30is mounted. The railroad ties28a,28bpreferably are manufactured from a conventional material such as wood, but can also be manufactured of other materials such as concrete, steel, wood laminate or other compositions. In one embodiment, the rail supporting portions40have conventional 9 by 9 inch cross-sectional shape, while the actuator mounting portions42have reduced heights as compared to the rail supporting portions40. For example, as shown inFIGS. 3 and 6, the actuator mounting portions42have heights H1which are smaller than corresponding heights H2of the rail supporting portions40. The actuator30is mounted on actuator mounting plates46secured to the top sides of the actuator mounting portions42of the ties28a,28b. The actuator mounting plates46include connector flanges48reinforced by gussets50.

The fixed rails22a,24aare secured to support plates60,62fastened to the top sides of the rail support portions40of the railroad ties28a,28b. Support plates60,62are preferably manufactured of a metal material such as steel. In one embodiment, the plates60,62have a thickness of less than 3 inches and most preferably about 2 inches. Plates60,62support the weight of the rails and also define guides or channels for supporting and guiding movement of the throw rod32, the lock rod34and the indication rod36. Spikes, bolts or other fasteners can be used to secure the plates60,62to the top sides of the ties28a,28b. The fasteners typically will extend through openings in the plates60,62. Rail reinforcement assemblies300can also be secured (e.g., welded) to the top sides of the plates60,62.FIGS. 2A and 2Bshow an example rail reinforcement assembly300including a rail brace301, a rail brace support plate302welded to the top plate of the tie, a locking plate304that interlocks with the brace301to prevent the brace301from sliding relative to the support plate302, and a clip306(e.g., an e-clip) for holding the locking plate304down. In use, the brace301is wedged between the support plate302and the rail (e.g., by hammering the brace in place across the top side of the top tie plate), and then locked in place by plate304and clip306.

Referring toFIG. 2, support plate60includes four separate pieces60a-60cand support plates62includes four separate pieces62a-62d. Connector plates66and fasteners64are used to secure dielectric spacers68between pieces60aand60b, between pieces60cand60c, between pieces62aand62b, and between pieces62cand62d. The insulators68prevent the support plates60,62from providing electrical connections between the rails of the track arrangement20. Dielectric spacers can also be used to electrically insulate the connector plates66from the top sides of the plates60,62(e.g., the insulators can extend between the connector plates66and the top sides of the plates60,62). Insulators (e.g., dielectric bushings) can also be used to electrically isolate the fasteners64from the connector plates66. The support plates60,62include connector flanges70supported by gussets72. Fasteners such as bolts can be used to secure the connector flanges70of the rail support plates60,62to the flanges48of the actuator mounting plate46. Flanges70and gussets72can be provided at both ends of the plates60,62to accommodate mounting the actuator30on either the left or right side of the tracks.

The support plates60,62are adapted for supporting the weight of the rails, and also for supporting and guiding the throw rod32. As shown inFIG. 2, the support plate60defines a channel80that extends along the length of the plate60between the rails of the track arrangement20. The channel80is sized to receive the throw rod32such that the throw rod32can slide back and forth along the length of the channel80. As shown atFIGS. 4 and 5, the channel80includes interior notches82that extend along the length of the channel80. The notches82are sized to receive corresponding projections84(seeFIG. 4A) that extend along a length of the throw rod32. A top side86of the channel80is open.

The support plates60,62also provide structural reinforcement to the throw rod32to prevent the throw rod32from excessively bending/flexing during usage. In one embodiment, the support plates60,62contact or are in close proximity to the throw rod32for a majority of the length of the throw rod32. In a preferred embodiment, the plates60,62contact the throw rod32for at least substantially the entire distance between the rails22b,24b. By providing the plates60,62in close proximity to or in contact with the throw rod32, debris is also inhibited from entering the channel between the plates60,62.

Referring still toFIG. 2, the throw rod32is connected to the actuator30by a linkage88. From the linkage88, the throw rod32extends through the flanges48,70and into the channel80defined by the support plate60. The throw rod32includes risers90(seeFIG. 3) that extend upwardly through the open top side86of the channel80. Pivot links92connect the risers90to brackets94fastened to the switch rails22b,24b. Each of the pivot links92includes two vertical pivotal axis95,96defined by pins that connect the links92to the risers90and the brackets94, respectively. The pivot links92provide a pivoting action that prevents the throw rod32from binding within the channel80as the throw rod32slides along the channel80to move the switch rails22b,24bbetween the two switch positions.

Referring toFIGS. 6-8, the rail support plate62defines channels108,110that extend along the length of the plate62. The channels108,110are adapted for respectively receiving the lock rod34and the indication rod36. The channels108,110guide linear movement of the lock rod34and the indication rod36. The support plate62supports the rails and prevents the lock rod34and the indication rod36from being crushed. The support plate62also reinforces the rods34,36along their lengths. In certain embodiments, substantially all of the lengths of the rods34,36between the rails are in contact with the support plate62. Lock rod34is coupled to the actuator30at linkage112and indication rod36is coupled to the actuator30at linkage114. Similar to the throw rod32, the lock rod34and the indication rod36extend through the flanges48,70and into the respective channels108,110. As shown atFIG. 2, risers190and pivot links192are used to couple the lock rod34to brackets194fastened to the switching rails22b,24b. Still referring toFIG. 2, risers290and pivot links292are also used to couple the indication rod36to brackets294fastened to the switching rails22b,24b. The pivot links prevent the rods34,36from binding within their respective channels108,110as the switching rails22b,24bare moved between the position ofFIG. 1Aand the position ofFIG. 1B.

It is preferred for the throw rod, the lock rod and the indication rod36to each have a construction that does not conduct electricity between the rails22a,22bor between the rails24a,24b. The ability to not conduct electricity is advantageous because trains often include safety circuitry that detects electrical current between the rails. If the rods electrically connect opposite rails, the operation of the safety circuitry could be compromised. In one embodiment, rods32,34and36are constructed of a dielectric material such as plastic. In other embodiments, rods can have a composite construction including both conductive and non-conductive materials. In still further embodiments, the rods32,34,36can have a dielectric coating. In certain embodiments, a layer such as Teflon or other low friction material (e.g., grease) can be provided within the channels or on the rods32,34,36to facilitate linear movement of the rods within their respective channels.

Since the switching arrangements disclosed herein are mounted on the top sides of railroad ties, the arrangements do not interfere with tamping operations.

In use, the switch rails22b,24bmay move in a longitudinal orientation (see orientation arrow400atFIG. 1A) when approaches and passes over the rails22b,24b. This is caused by the train pushing the rails as the train approaches the switch point and can be referred to as “running” the rails. In certain cases, the rails22b,24bmay move an inch or more in the direction of travel of the train. The switching arrangements ofFIGS. 9-12include structure for accommodating longitudinal movement of the rails22b,24b. In certain embodiments, the structures allow the rails22b,24bto move relative at least2inches in the longitudinal direction400relative to the throw rod coupled to the rails22b,24b. For example, the rails22b,24bcan move at least one inch in each direction along the orientation400relative to the central longitudinal axis of the throw rod coupled to the rails22b,24b. It will be appreciated that the same structures for allowing accommodating longitudinal movement of the switching rails relative to the throw rod can also be used in combination with the locking rod and the indicator rod to accommodate longitudinal movement of the switching rails relative to such rods.

FIGS. 9 and 10show a switching arrangement including a throw rod532. Similar to the previous embodiment, the throw rod532is slidably mounted in channel80defined by support plate60, and one end of the throw rod532is connected to actuator30that controls movement of the throw rod532within the channel80.

The throw rod532includes risers590that extend upwardly through the open top side of the channel80. The risers590are pivotally connected to rocker members591by pivot members592(e.g., pins, bolts, rivots, or other fasteners that allow pivotal movement). The rocker members591can pivot relative to the throw rod532about vertical axes593defined through the pivot members592. The rocker members591have curved surfaces594that engage planar surfaces595of brackets596secured (e.g., welded, fastened, or otherwise attached) to the switching rails22b,24b. The planar surfaces595are oriented generally perpendicular relative to the longitudinal axis of the throw rod532. Fasteners597(e.g., shoulder bolts) connect the rocker members591to the brackets596. For example, the fasteners597extend though holes598in the rocker members591and are anchored into the brackets596. Sufficient clearance exists between the holes598and the fasteners597to allow the rocket members591to rock or toggle relative to the brackets596. When the rocker members591rock relative to the brackets596, the curved surfaces594roll along the planar surfaces595of the brackets596. Springs599are provided on the fasteners597to bias the rocker members591to a central position where the central axes of the rocker members591are aligned with the longitudinal axis of the throw rod532.

In use, the rocker members591allow the switching rails22b,24bto move in the longitudinal orientation400relative to the throw rod532. For example, as the switching rails22b,24bmove along the orientation400relative to the throw rod532, the curved surfaces594of the rocker members591roll on the planar surfaces595of the brackets596and the rocker members591simultanteously pivot about the pivot axes593relative to the throw rod532to accommodate the longitudinal movement of the rails22b,24b. The rocker members591can pivot in either clockwise or counterclockwise directions about the axes593and the rocker members591can rock forward or backward to accommodate rail movement in either a forward or backward direction along the longitudinal orientation400.

To move the rails22b,24bto a position where rail22bengages rail24a(seeFIG. 9), the actuator30pushes the throw rod532along the longitudinal axis of the throw rod532in a direction away from the actuator30. As the throw rod is pushed, force is transferred to the rail22bby direct contact between the curved surface594of the rocker member591and the planar surface595of the bracket596attached to the rail22b, and force is transferred to rail24bthrough the fasteners597. To move the rails22b,24bto a position where rail24bengages rail22a, the actuator30pulls the throw rod532along the longitudinal axis of the throw rod532in a direction toward the actuator30. As the throw rod is pulled, force is transferred to the rail24bby direct contact between the curved surface594of the rocker member591and the planar surface595of the bracket596attached to the rail24b, and force is transferred to rail22bthrough the fasteners597.

FIGS. 11 and 12show a switching arrangement including a throw rod632. Similar to the previous embodiments, the throw rod632is slidably mounted in channel80defined by support plate60, and one end of the throw rod632is connected to actuator30that controls movement of the throw rod632within the channel80.

The throw rod632includes risers690that extend upwardly through the open top side of the channel80. The risers690are connected to members691. As depicted inFIGS. 11 and 12, the members691are rollers (e.g., roller bearings) that are free to rotate about vertical pivot axes695defined by pins696connected to the risers690. The members691fit within slots/tracks697defined by members699secured to the rails22b,24b. The slots/tracks697are aligned generally perpendicular to the longitudinal axis of the throw rod632.

In use, the members691,699allow the switching rails22b,24bto move in the longitudinal orientation400relative to the throw rod632. For example, as the switching rails22b,24bmove along the orientation400relative to the throw rod632, the members699move/slide relative to the members691in a direction perpendicular to the longitudinal axis of the throw rod632. The lengths of the slots/tracks697provide space to accommodate this relative movement. The members691are typically centered with the slots/tracks697when the switching rails are in their normal position. Thus, the members699can move a distance x in a forward direction relative to the members691to accommodate rail movement in the forward direction, and can also move a distance x in a backward direction relative to the members691to accommodate rail movement is a backward direction. In one embodiment, the distance x is at least 0.5 inches. In another embodiment, the distance x is at least 0.75 inches. In still another embodiment, the distance x is at least 1 inch.

To move the rails22b,24bto a position where rail22bengages rail24a(seeFIG. 11), the actuator30pushes the throw rod632along the longitudinal axis of the throw rod532in a direction away from the actuator30. As the throw rod632is pushed, force is transferred to the rails22b,24bthrough the slide members691which engage the guide members699secured to the rails22b,24b. To move the rails22b,24bto a position where rail24bengages rail22a, the actuator30pulls the throw rod632along the longitudinal axis of the throw rod532in a direction toward the actuator30. As the throw rod is pulled, force is transferred to the rails22b,24bthrough the slide members691which engage the guide members699secured to the rails22b,24b.

The above specification provides examples of how certain inventive aspects may be put into practice. It will be appreciated that the inventive aspects can be practiced in other ways than those specifically shown and described herein without departing from the spirit and scope of the inventive aspects. The description, like reference numbers have been used to identify like or similar parts.