Patent Application
20180023256
The present disclosure relates generally to fastening track rail to a substrate, and more particularly to a fastening mechanism with a base plate and a surrounding rail plate.
Rail equipment is widely used throughout the world for transportation of persons and all manner of goods. Rail lines formed by parallel track rails supported upon a concrete or gravel substrate will be familiar to most. Depending upon the manner of supporting the rails, and the type of substrate, different mechanisms are used for maintaining a desired positioning of the rails and, to a certain extent, attenuating shocks and vibrations transmitted between rail equipment and the underlying substrate. So-called “fixation” systems can range from relatively simple plates that attach rails to wooden ties partially buried in gravel, to more sophisticated mechanisms consisting of a relatively complex assembly of metallic and non-metallic components.
One known fixation system is set forth in United States Patent Application Publication No. 2015/0060561 to Ciloglu et al. Ciloglu et al. proposes a design where a section of track rail is supported between fasteners attached to a substrate and insulating elements. The design of Ciloglu et al. appears to be for the purpose of reducing corrosion-causing currents. The strategy is relatively complex, and for this and other reasons there remains ample room for improvement.
In one aspect, a fastening mechanism for coupling a track rail to a substrate includes a rail plate formed of a metallic material and including a lower side structured to face a substrate, and an upper side including a rail support surface extending between a front edge and a back edge of the rail plate. The rail plate further includes an outer perimeter and an inner perimeter defining an opening. The mechanism further includes a base plate formed of a metallic material, the base plate including a first lateral end and a second lateral end and having a first bore and a second bore formed therein, respectively. Each of the first bore and the second bore is structured to receive an anchor extending into the substrate. The base plate is positioned within the opening such that the rail plate surrounds the base plate and a gap extends peripherally between the rail plate and the base plate. The mechanism further includes an overmolded coating formed of a non-metallic material that is resiliently deformable relative to the metallic material. The overmolded coating encases the rail plate and the base plate and at least partially fills the gap to resiliently couple the rail plate and the base plate together.
In another aspect, a system for coupling a track rail to a substrate includes a fastening mechanism including a rail plate, a base plate, and an overmolded coating encasing the rail plate and the base plate. Each of the rail plate and the base plate are formed of a metallic material and the overmolded coating is formed of a non-metallic material. The rail plate includes a lower side structured to face a substrate, and an upper side including a rail support surface extending between a front edge and a back edge of the rail plate. The rail plate further includes an outer perimeter and an inner perimeter defining an opening. The base plate includes a first lateral end and a second lateral end having a first bore and a second bore formed therein, respectively, and each structured to receive an anchor extending into the substrate. The base plate is positioned within the opening such that a gap extends peripherally between the rail plate and the base plate, and the overmolded coating at least partially fills the gap.
In still another aspect, a method of fastening a track rail to a substrate includes attaching a base plate formed of a metallic material to a substrate by way of fasteners extending through bores in opposite lateral ends of the base plate. The method further includes positioning a rail plate formed of a metallic material and surrounding the base plate in a service orientation relative to the substrate by way of the attaching of the base plate. The method still further includes clamping a track rail against a rail support surface of the rail plate to establish a load transmission path between the track rail and the substrate by way of a resilient non-metallic material in an overmolded coating encasing the base plate and the rail plate.
Referring to
Fastener body 12 further includes an outer perimeter 32 defining a generally rectangular footprint. Each clip receiver 22 and 24 may be positioned at least partially and may be entirely within the rectangular footprint. As will be further apparent from the following description, internal components of fastener body 12 including a rail plate not visible in
Referring also now to
Referring also now to
It will be recalled that coating 50 is formed of a non-metallic material that is resiliently deformable relative to the metallic material of base plate 46 and rail plate 48, which metallic materials may be but are not necessarily the same. Coating 50 encases rail plate 48 and base plate 46 and at least partially fills gap 90 such that rail plate 48 and base plate 46 are resiliently coupled together. It can also be seen from
Referring also now to
Also shown among the various figures are bores 74 and 76 that receive anchors 20 and/or clamping mechanisms 42 and 44, respectively. In a practical implementation strategy, fastening mechanism 10 is structured to enable lateral adjustability, a feature altogether lacking or commonly inadequate in known designs. To this end, it can be seen that first bore 74 and second bore 76 are non-circular, each having a relatively greater extent in lateral directions, i.e. toward or away from ends 70 and 72, and a relatively lesser extent in fore and aft directions, i.e. toward or away from edge 134 and edge 136. Anchor bolts or the like within bores 74 and 76 can be positioned relative to base plate 46 through a range of lateral positions. Base plate 46 is also shown to further include a first set of indexing elements 52 adjacent first bore 74 and a second set of indexing elements 52 adjacent second bore 76. Each of the sets of indexing elements 52 is structured to couple with a clamping mechanism, such as a clamping collar 80 as shown in
Referring to the drawings generally, when it is desired to fasten a track rail to a substrate, such as upon installation of new track or retrofitting of fastening mechanisms to an old track, base plate 46 may be attached to an underlying substrate by way of fasteners such as anchors 20 extending through bores 74 and 76 in the opposite lateral ends 70 and 72 of base plate 46. Rail plate 48 may be positioned, by way of the attaching of base plate 46, in a service orientation relative to the underlying substrate. Those skilled in the art will appreciate that rail support surface 64 will be thusly positioned either at a horizontal orientation, or an orientation tilted slightly inward toward a center line running longitudinally between adjacent track rail paths. In one implementation, clamping mechanisms 42 and 44 may include anchoring bolts that are received within threaded sleeves or the like embedded in the underlying substrate. In other instances, clamping mechanisms 42 and 44 could include only the nuts, washers or other hardware that is used to attach mechanism 10 to a preexisting anchor held fast within a substrate.
With base plate 46 and rail plate 48 positioned as desired and mechanism 10 clamped to the underlying substrate, a track rail may be clamped against rail support surface 64 of rail plate 48, so as to directly contact rail support surface 64 or to contact a layer of overmolded coating or another material placed upon rail support surface 64. As described herein, clips 26 and 28 may be used in a generally conventional manner to clamp a track rail such as track rail 18 to mechanism 10, and thereby support track rail 18 relative to the underlying substrate. Clamping track rail in this manner establishes a load transmission path between track rail 18 and the substrate by way of resilient non-metallic material of coating 50. As discussed above, base plate 46 may be attached at one of the plurality of lateral attachment positions within an available range of lateral attachment positions. Clamping track rail 18 can therefore also include clamping track rail 18 at a selected lateral mounting location relative to pre-established anchoring locations so as to establish the load transmission path by way of the non-metallic material of coating 50 that is resident within gap 90.
Those skilled in the art will be familiar with other track fixation systems where a base clamped to a substrate surrounds a rail plate or the like. In such a strategy, while the base may be robustly supported upon the substrate, and the track rail capable of moving slightly relative to the base, various disadvantages or limitations result from such a design. On the one hand, a lateral length of a track rail fastening mechanism, oriented transverse to the rail, is sometimes limited due to proximity of a vertical wall such as a wall of an adjacent structure or some other permanent feature adjacent a rail line. With such a limitation on length, lateral stiffness of the track rail fastening mechanism of conventional design may be less than optimal, allowing the rail to rotate relatively more easily than what would otherwise be desired. The undesired ease of rotation is believed to be due at least in part to a lack of vertical supporting elastomeric material under lateral sides of the rail plate. The present disclosure provides for substantially higher lateral stiffness at least in part because the rail plate is not confined in length by the surrounding base plate, since the base plate is instead itself surrounded by the rail plate. While adjacent walls or other structures can still place limits on the overall length of a track rail fastening mechanism, among other things the present disclosure enables more of the available length to be taken up by rail plate than conventional approaches. The present disclosure also provides close proximity of anchor bolts to the rail and, in return, full vertical support by elastomeric material between the substrate and lateral ends or all four angles of the rail plate. The design thus has robust lateral stability resulting in reduced rail tilting, in a fastener having a relatively short lateral length. Such a solution can also be beneficial in scenarios where two competing requirements need to be met at the same time, such as soft elastomeric material in conjunction with short lateral length fasteners.
The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present disclosure in any way. Thus, those skilled in the art will appreciate that various modifications might be made to the presently disclosed embodiments without departing from the full and fair scope and spirit of the present disclosure. Other aspects, features and advantages will be apparent upon an examination of the attached drawings and appended claims.
