1. The Field of the Invention
Exemplary embodiments of the invention relate to transportation. More particularly, exemplary embodiments relate to transportation by rail. More particularly still, exemplary embodiments of the invention relate to stacked railway ties.
2. The Relevant Technology
Railway systems play an important role in North American and other worldwide economies. Railway systems can be adapted to run over land or water and thus provide a quick, reliable, convenient, and generally inexpensive method of transportation for both products and people.
Railway systems run over sets of tracks, and each track is made up of one or more rails. A railway tie is a well-known apparatus for use in supporting a rail. In practice, multiple ties are spaced to support sections of the rail so as to form the track over which a train may run. Railway ties may be made of a variety of materials including timber, reinforced concrete, composites, such as plastic composites or carbon, or steel. A railway tie may comprises a solid block which has upper and lower surfaces for contacting a rail and ballast, respectively. In operation, the railway tie is either placed on the ballast or partially submerged within the ballast, and the rail is secured to the upper surface of the railway tie. For example, when the railway tie is comprised of timber or plastic composite, the rail is secured to the railway tie via a tie plate.
As a train moves along a rail and across the railway ties, the tie supports the weight of the train and helps to transfer at least a portion of the load to ballast. Train movement also creates frictional forces and vibrations which may cause the railway ties to shift position or which may cause ballast to migrate and thereby cause cavities or otherwise reduce the ballast in contact with the railway tie. If the ballast migration is left uncorrected, the railway tie may be unable to effectively transfer load to the ballast and may fail. Alternatively, the shift in the ballast may cause the railway tie and the rail to fall out of alignment. Failure or misalignment of a railway tie can cause misalignment of the track, which can ultimately result in train derailment. To reduce ballast migration, and ultimately to prevent derailment, the crib (the void between adjacent ties) can be filled with additional ballast. To the extent the additional ballast does not effectively prevent ballast migration, expensive processes may be necessary to refill cavities, or alternatively, removal and/or replacement of the ties may be required.
Commonly, equipment such as switch rods, electric wire conduits, or other track components are placed or run between ties. When this equipment is in place between the ties, the crib is reduced. With the crib reduction there is less ballast filled in between railway ties, and greater ballast migration may result under the ties. One approach to resolve this is to allow for greater clearance for the equipment by raising the railway tie, and thereby reducing or eliminating the partial submersion within the ballast. While reducing the submersion of the railway tie allows for greater clearance and more ballast to fill the crib, the contact with ballast below the tie is reduced, which increases the tendency for cavities to form. Reducing the submersion of the tie also reduces the railway tie's resistance to lateral and longitudinal movement or displacement.
Railway ties have a limited service life before replacement becomes necessary. When the rail is connected to the railway tie, the weight of the rail and passing trains stresses the tie, with the stress being most concentrated near the areas where the rail contacts the tie and where the tie contacts ballast. Additional stress is placed on the tie from the removal and/or replacement of rails. Over time, the continual and cyclical loads on the stressed railway tie may cause the tie to fail, so as to require replacement. Additionally, train derailment may uproot a railway tie or may sufficiently damage a tie so as to necessitate replacement. When the service life ends and replacement is necessary, the tie is completely removed and a new tie is placed in or on the ballast. Often, where ballast migration occurred, replacement may be time consuming and/or expensive because ballast may need to be refilled and repacked before the new tie can be positioned.
Railway ties made of timber and steel have been used for more than a hundred years, and railway ties made with reinforced concrete have been used for the last thirty years. Traditionally, steel ties were more expensive than concrete or timber ties, but had a longer service life. Due in part to converging prices of steel and timber, the popularity of steel ties is increasing even where a timber tie has been treated with creosote to improve its service life. In part, this increased popularity is the result of other cost savings that can be realized by using steel ties. For example, steel ties are lighter than the timber or concrete counterparts so transportation costs are reduced. Because of the reduced weight, the dead loads that must be supported by bridges and foundations for railway tracks are also reduced. Additionally, steel ties wear better than timber ties in humid, wet environments, are not affected by insect infestation, do not suffer from plate cutting or spike kill, require less ballast per mile, allow greater load spreading capabilities, can be spaced at greater distances, are recyclable, require less material handling, and have better derailment survivability than either timber or concrete ties.
Despite the advantages that steel offers, timber ties are the traditional choice for most railroad applications, and are often used where the track carries electrical circuits for electrical signal systems or to reduce vertical pullout. Approximately twenty percent of the track mileage in North America has track signal systems using track circuits. A track circuit uses the rails as the conductors and the train wheels and axles as the switch for activating signals. Unlike timber ties, steel ties can conduct electricity. Thus, timber ties are more commonly used on tracks employing track circuits because steel ties can complete the track circuit and disrupt the signaling systems. Where track signal systems are necessary in conjunction with conductive ties, such as steel ties, insulator systems are required to reduce or prevent short-circuit of the electrical current through the conductive tie material. All concrete ties require rail seat insulation systems to protect the concrete from damage that would be imparted by direct contact with the steel rail regardless of track signal requirements.
Embodiments of the present invention relate to a stacked railway tie that supports the weight of a train by transmitting the load to ballast. A stacked railway tie can allow for improved track surface and alignment, while also providing greater clearance for railway equipment. A stacked railway tie can further allow the tie to be positioned deeper into the ballast, thus reducing ballast migration and improving the service life of the tie. The present invention can be helpful in railway environments where ballast migration may occur and where vertical, lateral and longitudinal forces may displace the tie and cause track misalignment. Additionally, the present invention may reduce ballast migration in areas where the crib is reduced or removed in order to accommodate railway equipment.
In one exemplary embodiment of the invention, a stacked railway tie includes a base deck, a top deck stacked on and coupled to the base deck by a fastening system, and a deck spacer positioned between the top and base decks. The stacking of the top deck on the base deck can allow the base deck to be positioned deeper into the ballast underneath the top deck such that ballast migration is reduced. This can be particularly useful in settings where the crib or the ballast positioned between ties is reduced or eliminated in order to accommodate other railway equipment, or in other applications where ballast is reduced.
The base deck may be configured to be positioned within and/or on top of ballast. The top deck may be configured to have at least one rail mounted thereon to in turn couple the rail to the base deck. Such a configuration of the stacked railway tie may facilitate transmission of the load force ultimately to the ballast positioned beneath the base deck. The stacking of decks may allow the base deck to be positioned deeper within the ballast yet still maintain the height of the rail to an adequate level such that elevation requirements are met. The stacked railway tie may further include a fastening system configured to couple the top deck to the base deck. In one embodiment, the fastening system includes one or more clamps. In other embodiments, the fastening system includes one or more bolts. In some embodiments, the stacked railway tie further includes a second fastening system that can be configured to couple at least one rail to the top deck.
The stacked railway tie may further include a deck spacer positioned between the top and base decks in order to offset the top deck from the base deck. The deck spacer can be configured to facilitate transmission of the load force induced on the top deck to the base deck and thus the ballast positioned beneath the base deck, and to support the load force placed thereon from an over-passing train. Additionally, the deck spacer may be used to adjust the height of the top deck, thus facilitating correct alignment of a rail.
In some embodiments, the stacked railway tie may further include a ballast displacement system to distribute a load on the tie to ballast. The ballast displacement system may connect to the underside of the base deck, and can increase the surface area of the stacked railway tie that is in contact with ballast. The ballast displacement system may include a single block or multiple blocks which can distribute the load from the base deck to ballast.
In an alternative embodiment, a stacked railway tie includes a base deck, a top deck stacked on the base deck and electrically insulated from the base deck. Electrical isolation between the base deck and the top deck may be enabled by employing nonconductive side plates, deck spacers, and/or side posts. The side plates and deck spacers can maintain a separation between the base deck and the top deck, thus preventing conduction. Side posts isolate the top deck from the fasteners, and may also include ramps to allow proper positioning of the fasteners.
In an alternative embodiment, a stacked railway tie may include a base deck, a first top deck stacked on the base deck, and a second top deck stacked on the first top deck and electrically insulated from the first top deck. Electrical isolation between the first top deck and the second top deck may be enabled by employing nonconductive side plates, deck spacers, and/or side posts. The side plates and deck spacers can maintain a separation between the first top deck and the base deck, thus preventing conduction. Side posts isolate the first top deck from the fasteners, and may also include ramps to allow proper positioning of the fasteners.
In one embodiment, a method for making a stacked railway includes providing a base deck, placing a spacer on the base deck, stacking the top deck on the base deck such that the spacer can be positioned between the base deck and the top deck, securing the top deck to the base deck, and securing a rail to the top deck. In some embodiments, securing the top deck to the base deck or rail may be done with a clamp or bolt. In other embodiments, the method for making a stacked railway tie further includes the step of insulating the top deck from a second top deck.
In another embodiment, a method for distributing a load between a stacked railroad tie and ballast includes providing a base deck and configuring that deck to receive a top deck, coupling the top deck to the base deck, configuring the top deck to distribute a load to the base deck, placing a ballast displacement system in communication with the base deck, and adapting the ballast displacement system to distribute a load on the base deck to ballast. Distribution of the load from the top deck to the base deck may include positioning a spacer between the top and base decks.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that not all of these and other contemplated advantages are required in all embodiments of the invention. It is further appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
a is a frontal view of a stacked railway tie illustrating a top deck stacked on a base deck wherein a single track is coupled to the top deck;
b is a top view illustrating the stacked railway tie of
The present invention is directed to a stacked railway tie having multiple decks through which the weight of a train can be transmitted to ballast. A feature of one exemplary embodiment can be at least one top deck that can increase clearance for railway equipment, and which can be removable to enable quick and effective replacement or repositioning of the deck and rails. The top deck may be selectively fastened to other components of the tie. The present invention can be helpful in railway environments where rails need to accommodate railway equipment in the crib, where adjustments are necessary to improve track alignment, or where replacement of the removable deck is necessary. The stacked railway tie of the present invention can further act to reduce ballast migration in areas where the crib is reduced or eliminated in order to accommodate railway equipment.
a and 1b illustrate an exemplary embodiment of a stacked railway tie 10. According to one embodiment of the present invention, stacked railway tie 10 can be configured to reduce ballast migration in areas where the crib is reduced or removed in order to accommodate additional railway equipment such as switch rods, electric wire conduits, or other track components. In the illustrated embodiment, stacked railway tie 10 includes a base deck 12 and a top deck 14 stacked on top of and coupled to base deck 12. Stacking of decks in this manner may provide many advantages. For instance, the additional weight introduced into stacked railway tie 10 from top deck 14 can increase the deadweight of the tie. Increasing the tie's deadweight can improve the vertical pullout. Additionally, the stacking of top deck 14 and base deck 12 can improve switch rod clearance, and drainage and deicing from around the track. Further, stacked railway tie 10 can reduce the stress on the base deck when rails or tracks are removed and/or replaced. Also, in the event of a train derailment, stacked railway tie 10 can be less expensive to fix due to the need to replace only the top deck.
Base deck 12 may be configured to transmit the weight of an over-passing train and any equipment attached to the stacked railway tie 10 to the ballast positioned beneath base deck 12. Base deck 12 may further be configured to have another deck stacked thereon, such as top deck 14. In the illustrated embodiment, base deck 12 includes a mounting surface 16, sides 18a, b, and an underside 20. In one embodiment, mounting surface 16 can be substantially flat such that fasteners, spacers, equipment, or track components can easily be mounted thereon and coupled thereto. Underside 20 of base deck 12 may also be substantially flat and configured to have equipment mounted thereon. Base deck 12 can be made from a single piece of steel. However, in alternative embodiments, base deck 12 can be made of composite material, other metals, or any other material sufficient to withstand the forces induced thereon by a train and any equipment attached or mounted to base deck 12. Further, in alternative embodiments, base deck 12 may include multiple pieces of material such as, for example, separately formed sides 18a, b. In one embodiment, base deck 12 is a steel tie.
Top deck 14 may also be configured to transmit the weight of a train and any equipment, rails, or components attached or mounted to top deck 14 to base deck 12. Top deck 14 may further be configured to have another deck stacked thereon. In addition, top deck 14 can be configured to have at least one rail coupled to top deck 14. In the illustrated embodiment, top deck 14 includes a mounting surface 22, sides 24a, b, and an underside 26. Mounting surface 22 may be substantially flat and/or configured to have equipment and at least one rail mounted thereon and coupled thereto. In the illustrated embodiment, top deck 14 has mounted thereon rails 28a, b. Top deck 14 can be made from a solid piece of steel. However, in alternate embodiments, top deck 14 can be made of a composite material, a metal, or any other material sufficient to withstand the normal forces induced in a railway tie. In still other embodiments, top deck may include multiple pieces including, for example, separately formed sides 24a, b, or multiple pieces forming mounting surface 22. In one embodiment, top deck 14 is a steel tie.
In the illustrated embodiment, top deck 14 is stacked on base deck 12 and can be coupled thereto by first fastening system 30. The coupling of top deck 14 to base deck 12 can facilitate coupling of rails 28a, b to base deck 12. First fastening system 30 may be configured to couple top deck 14 to base deck 12. In one embodiment, first fastening system 30 includes first fastener 32a and second fastener 32b. Using first fastener 32a and second fastener 32b in tandem may present many advantages. For example, where the sides of top deck 14 are prone to lateral, longitudinal, or vertical displacement, first fastener 32a and second fastener 32b can each limit the displacement of one end, thus limiting the displacement of top deck 14 as a whole.
First fastener 32a may further be configured to reduce the lateral, longitudinal, and vertical movement and displacement of top deck 14. In one embodiment, first fastener 32a is coupled to mounting surface 16 of base deck 12 and secured to mounting surface 22 of top deck 14 so as to reduce vertical and lateral movement of top deck 14. First fastener 32a may be mounted to mounting surface 16 of base deck 12 and secured to mounting surface 22 of top deck 14 with any conventional method including, for example, welds, hooks, lynch pins, brackets, or bolts. In the illustrated embodiment, first fastener 32a abuts a terminating edge of top deck 14 so as to reduce longitudinal movement or displacement of top deck 14.
First fastener 32a may also be configured to be selectively releasable, such that top deck 14 can be removable. In the illustrated embodiment, first fastener 32a includes a clip 36a and a shoulder clamp 38a combination. Clip 36a may be positioned over top deck 14. In the illustrated embodiment, clip 36a is in communication with top deck 14 and can apply a force which limits the vertical and lateral movement by top deck 14. To remove top deck 14, clip 36a can be lifted and taken out of communication with top deck 14. It should be appreciated by a person of ordinary skill in the art in view of the disclosure provided herein that the illustrated first fastener 32a is exemplary only and that alternative embodiments are within the scope of this invention. For example, first fastener may permanently couple top deck 14 to base deck 12 through a weld, rivet, or the like. Alternatively, other selectively releasable fasteners such as, for example, bolts or C-clamps are contemplated.
In one embodiment, second fastener 32b is configured in substantially the same way as first fastener 32a, and/or can be identical to first fastener 32a. Second fastener 32b may be coupled to mounting surface 16 of base deck 12 and secured to mounting surface 22 of top deck 14 so as to reduce vertical and lateral displacement of top deck 14. In one embodiment, second fastener 32b abuts a terminal edge of top deck 14 so as to reduce longitudinal movement and displacement of top deck 14. In the illustrated embodiment, second fastener 32b includes a clip 36b and a shoulder clamp 38b combination. It is appreciated that it is not necessary that second fastener 32b and first fastener 32a be identical, or that first fastening system 30 have a first fastener 32a and a second fastener 32b. For example, first fastening system 30 may be configured to reduce the lateral, longitudinal and vertical movement or displacement of top deck 14 with any number of fasteners, including a single fastener or more than two fasteners.
In another embodiment, stacked railway tie 10 may further be configured to have rails 28a, b mounted and fastened thereon. Stacked railway tie 10 may also include a second fastening system 44 configured to couple rails 28a, b to top deck 14. Coupling of rails 28a, b to top deck 14, in combination with first fastening system 30 coupling top deck 14 to base deck 12, links and couples rails 28a, b ultimately to base deck 12. In the illustrated embodiment, second fastening system 44 includes a first fastener 46a and a retention plate 48a. First fastener may be configured to reduce lateral, longitudinal and vertical displacement of rail 28a. In one embodiment, first fastener 46a is coupled to mounting surface 22 of top deck 14. In some embodiments, first fastener 46a can abut an edge of the base of rail 28a and can be secured against the base of rail 28a so as to reduce vertical, lateral and longitudinal displacement of rail 28a. In the illustrated embodiment, first fastener 46a includes a clip 50a and a shoulder clamp 52a combination. Clips 50a, b, as well as clips 36a, b, can be resilient and made of steel. However, as will be appreciated by one of ordinary skill in the art in view of the disclosure provided herein, clips 36a, b and 50a, b may embody a variety of other characteristics and need not be resilient, and may also be made of different metals or composite materials.
In still other embodiments, retention plate 48a may be configured to reduce lateral movement of rail 28a. In one embodiment, retention plate 48a includes a substantially flat piece of metal such as steel, and can be mounted on mounting surface 22 of top deck 14. The coupling of first fastener 46a, and the mounting of retention plate 48a to mounting surface 22 of top deck 14, may be done by any conventional means including, for example, welds, rivets, or bolts. Retention plate 48a may further be configured to substantially prevent lateral movement of rail 28a when rail 28a is mounted on top deck 14 and first fastener 46a is coupled to top deck 14 and secured against the base of rail 28a.
In one embodiment, retention plate 48a is positioned on top deck 14 a distance away from first fastener 46a that is sufficient to allow the base of rail 28a to be positioned there between. The distance between first fastener 46a and retention plate 48a should not be so great so as to allow gaps to form between rail 28a and either first fastener 46a or retention plate 48a. In the illustrated embodiment, the combination of first fastener 46a and retention plate 48a can substantially minimize gaps around the bottom of rail 28a, and can reduce the lateral movement of rail 28a.
Rail 28b may be coupled to top deck 14 in substantially the same way as rail 28a. In one embodiment, rail 28b is coupled to top deck 14 by second fastener 46b and retention plate 48b. In the illustrated embodiment, first fastener 46a can be identical to first fastener 46b and retention plate 48a can be identical to retention plate 48b. However, it is not necessary that first fastener 46a be identical to second fastener 46b, nor that retention plate 48a be identical to retention plate 48b. As will be appreciated by one of ordinary skill in the art in view of the disclosure provided herein, a variety of types and configurations may be utilized as first fastener system 30 or second fastener system 44 without departing from the spirit and scope of the invention. For example, clamps, welds, tie fasteners, bolts, rivets, brackets, braces, and end fasteners are all within the scope of the present invention.
a further illustrates the use of a deck spacer 54 and a ballast displacement system 56 utilized in connection with stacked railway tie 10. In one embodiment, deck spacer is positioned between base deck 12 and top deck 14. Ballast displacement system 56 may be located below base deck 12 such that it is positioned to be in contact with the ballast.
Deck spacer 54 may further be configured to support top deck 14 and to distribute loads to base deck 12. In the illustrated embodiment, deck spacer 54 includes a block of material having a length substantially equal to or larger than the length of top deck 14. Deck spacer 54 may also have a predetermined thickness according to the desired separation of top deck 14 from base deck 12. Deck spacer 54 can be made of different types of material such as a metal, polymer, or a composite, or from a variety of other materials that are sufficient to substantially support top deck 14 and distribute loads through to base deck 12 without failure. Deck spacer 54 can be a single piece of material or multiple pieces of material, and may be solid or hollow. In one embodiment, the construction shape and type of material can be such that deck spacer 54 substantially supports top deck 14 and substantially distributes load to base deck 12. Deck spacer 54 can be made from mild steel, High Density Polyethylene (“HDPE”), Ultra High Molecular Weight Polyethylene (“UHMW”), or polyurethane.
Deck spacer 54 may further be configured to improve track surface and alignment, and to improve clearance for switch rods, electric wire conduits, or other track components, while not requiring replacement or adjustment of base deck 12. One feature of embodiments utilizing deck spacer 54 in relation to stack railway tie 10 is that deck spacer 54 can provide adjustability as to the height of top deck 14 in relation to base deck 12 and in relation to the ballast positioned beneath base deck 12. Deck spacer 54 may be replaced, or the width of deck spacer 54 may be modified. Consequently, the base deck 12 can remain deep into ballast while a change in deck spacer 54 can alter the height of top deck 14. This feature can be particularly useful where crib is reduced for clearance, as base deck 12 can remain deep in the ballast, while the height of top deck 14 is increased. Further, deck spacer 54, when made from a nonconductive material, provides for a nonconductive layer between top deck 14 and base deck 12, which may facilitate the use of steel railway ties even where the track carries electrical circuit systems.
Deck spacer 54 may also be configured to extend the service life of stacked railway tie 10. In one embodiment, deck spacer 54 can operate in connection with ballast displacement system 56 to facilitate the distribution of loads to the ballast positioned beneath base deck 12, thus reducing the stress on stacked railway tie 10 and prolong the service life of top deck 14, base deck 12, and stacked railway tie 10. Additionally, top deck 14 may be stacked on base deck such that sides 24a, b are in communication with sides 18a, b of base deck 12. While it is not necessary for sides 24a, b of top deck 14 to be in contact with sides 18a, b of base deck 12, such a configuration, in combination with deck spacer 54, can provide for a more stable and rigid stacked railway tie 10, thus also contributing to an extended service life of stacked railway tie 10.
As will be appreciated by one of ordinary skill in the art in view of the disclosure provided herein, ballast displacement system 56 is not limited to a solid block of material. In other embodiments, ballast displacement system 56 may include, for example, a hollow block or multiple blocks spaced along the length of base deck 12. In still other embodiments, ballast displacement system 56 may include plating. Ballast displacement system 56 may be comprised of a material that is a metal, a composite, or some other material. A suitable material for ballast displacement system 56 can be capable of supporting base deck 12 and distributing loads to the ballast without failure. Ballast displacement system 56 can include steel and/or HDPE composite.
In one embodiment, ballast displacement system 56 is coupled to underside 20 of base deck 12 via welding or through brackets and screws. Utilizing ballast displacement system 56 in conjunction with stacked railway tie 10 can provide many advantages. For example, ballast displacement system 56 may reduce the void space beneath base deck 12 such that more surface area of stacked railway tie 10 and base deck 12 are in contact with the ballast positioned beneath base deck 12. The reduction of void space beneath base deck 12 can provide increased support for base deck 12, provide for the longer service life of stacked railway tie 10 due to reduction of stress on base deck 12, and provide for a more solid base for the track coupled to stacked railway tie 10, thus improving the track surface and alignment.
In the illustrated embodiment, stacked railway tie is configured to electrically insulate first top deck 14a from second top deck 14b by using side plates 58, side post insulators 60, and a nonconductive deck spacer 54. When stacked railway tie 10 supports two rails 28a, b, the illustrated embodiment further demonstrates that to electrically insulate rail 28a from rail 28b, it may not be necessary to utilize nonconductive side plates 58a, b nor side post insulators 60a, b in connection with top deck 14b. However, as will be appreciated by those of skill in the art, rails 28a, b could easily be electrically insulated from base deck 12 by utilizing nonconductive side plates, side post insulators, and nonconductive deck spacers similar to those utilized with top deck 14a.
Side plate 58a may be positioned between the sides of top deck 14a and base deck 12, such that side plate 58a separates top deck 14a from base deck 12. Side plate 58b may also be oriented in a similar manner as side plate 58a. However, side plate 58b may separate the opposing sides of top deck 14a and base deck 12. In the illustrated embodiment, side plates 58a, b include a flat, nonconductive and resilient plate extending at least the length of top deck 14a. In other embodiments, side plates 58a, b may be shorter than top deck 14a so long as the length is sufficient to maintain the separation of top deck 14a from base deck 12. Side plates 58a, b can be made from HDPE, UHMW or polyurethane. Alternatively, side plates 58a, b may include a metal and a nonconductive composite combined in such a way that the overall side plate is nonconductive. In still other embodiments, other nonconductive materials can be used and have sufficient mechanical properties to withstand the forces exerted on it by top deck 14a and base deck 12. Side plates 58a, b may also have a predetermined width and thickness that is sufficient to separate the sides of base deck 12 and top deck 14a. The shape of side plates 58a, b, can determine separation of sides 18a, b of base deck 12 from sides 24a, b of top deck 14 and, in conjunction with them being made of a nonconductive material, may facilitate electric insulation of rail 28a from rail 28b.
In some embodiments, side post insulators 60a, b can be configured to facilitate electric insulation of rail 28a from rail 28b. In the illustrated embodiment, side post insulator 60a can be identical to side post insulator 60b. As such, description will now be given with reference to only side post insulator 60a. However, it is not required that side post insulator 60b be identical to side post insulator 60a. In one embodiments, side post insulator 60a includes a piece of resilient nonconductive material for facilitating electrical insulation between top deck 14a and fastener 32. Side post insulator 60a can be made of HDPE, UHMW or polyurethane, although other nonconductive materials, or a combination of materials that are nonconductive, are also contemplated.
In the illustrated embodiment, side post insulator 60a can be shaped and positioned such that a portion of side post insulator 60a separates shoulder clamp 38 from the edge of top deck 14a, and separates steel clip 36 from mounting surface 22 of top deck 14a. In this manner, side post insulators 60a, b can facilitate the electrical insulation of rail 28a from rail 28b. Utilization of side plates 58a, b, side post insulators 60a, b and deck spacer 54 may provide substantial electric insulation of rail 28a from rail 28b. As will be appreciated by those skilled in the art in view of the disclosure provided herein, a variety of types and configurations of side post insulators and side plates and/or deck spacers can be utilized without departing from the scope and spirit of the present invention. For example, deck spacer 54, side plates 58a, b, and/or side post insulators 60a, b may comprise non-resilient materials, a side post insulator may be shaped and positioned in such a way that separates shoulder clamp 38 from mounting surface 16 of base deck 12, or a deck spacer may act as both deck spacer and side plate.
As shown in
As will be appreciated by one having ordinary skill in the art in view of the disclosure provided herein, ramps 62 may also be formed of a variety of conductive or nonconductive materials that can support the load on the fastener 36 and side post insulators 60a, b, including HDPE, metals, or composite materials. Other methods of securing the ramp to top deck 14 may also be used including rivets, brackets and screws, or friction. Side post insulators 60a, b can be placed on ramp 62 and secured by friction created by clip 36. However, one of ordinary skill in the art in view of the disclosure provided herein may also appreciate that ramp 62 may also be secured to side post insulators 60a, b by other suitable methods.
In the illustrated embodiment, rails 28a, b can be coupled to top decks 14a, b rather than to a single top deck 14. As will be appreciated by one of ordinary skill in the art in view of the disclosure provided herein, varying numbers of top decks 14a, b may be used in appropriate conditions. In one embodiment, top deck 14a can be substantially the same height as top deck 14b. However, multiple top decks 14a, b can enable the ability to independently vary the height of rails 28a, b with respect to base deck 12. Deck spacers 54 may vary the height of stacked railway tie 10 by creating a separation between top decks 14a, b and base deck 12. Where multiple deck spacers 54 are used, top deck 14a may be raised to a different height than top deck 14b. This can be advantageous in various circumstances, including where only one of rails 28a, b is out of alignment, or where rails 28a, b are both out of alignment but to differing extents.
An additional feature of stacked railway tie 10 with separate top decks 14a, b can be a reduced deadweight. In the illustrated embodiment, there can be a longitudinal separation between top decks 14a, b. Longitudinal separation between top decks 14a, b can result in decreased deadweight as compared to a stacked railway tie 10 of equal length but with a single top deck 14, such as that depicted in
In addition, the illustrated embodiment demonstrates an alternative embodiment of ballast displacement system 56. Ballast displacement system 56 may include a substantially flat plate 42 and a U-shaped channel 40. In one embodiment, channel 40 can be in contact and positioned against underside 20 of base deck 12, and plate 42 can be positioned on the bottom side of channel 40. Further, plate 42 may also be in contact with and/or coupled to the inside surface of sides 18a, b of base deck 12. Plate 42 may be coupled to base deck 12 and channel 40 via welding, rivets, brackets and screws, or by some other fastening means. It should be a appreciated by one of ordinary skill in the art in view of the disclosure provided herein that channel 40 may be of a variety of cross-sectional shapes and configurations, and may be, for example, hollow, solid, rectangle, trapezoid, or an I-beam. Alternatively, either channel 40 or plate 42 may be eliminated, or plate 42 and channel 40 may be integrally formed. Additionally, it should be appreciated that plate 42 does not need to be substantially flat, and may be, for example, arched, crimped, or bent.
It will be appreciated by one of ordinary skill in the art in view of the disclosure provided herein that the invention can be utilized in various railway configurations. For example, the invention can be utilized in connection with standard railway tracks, or alternatively with switches or turnouts, crossovers, diamonds or other configurations. Furthermore, the present invention can be configured to accommodate other trackwork material such as a frog, guard rail or switch point.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application claims benefits from U.S. Provisional Patent Application, Ser. No. 60/730,195, filed on Oct. 25, 2005, entitled “STACKED RAILWAY TIE”, the disclosure of which is hereby incorporated by reference.
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Number | Date | Country | |
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