Rail-fastening for rails

Abstract: A rail fastener (16) for fastening rails (15a, 15b) to a support structure, particularly adapted for use in switches, crossovers, frogs and the like where a track plate must support a pair of closely spaced or nonparallel rails. The rail fastener (16) includes a rigid track plate (17) to which the rail is adjacent and two fastener pads (20) laterally spaced on the track plate (17) and disposed between the track plate (17) and the support structure. Each fastener pad has a rigid member (21) and a resilient member (23) bonded together and two pins (22a, 22b) to join the resilient member (23) to the track plate (17).

Description: The present invention relates to systems for fastening railroad rails to an underlying support structure, and particularly to such fastening systems for special trackwork such as switches, crossovers and guardrails in rapid transit rail systems. In the past, fasteners for attaching railroad rails to support structures have included a track plate secured to the bottom of each rail by suitable clamping devices, together with an underlying layer of elastomeric material abutting the support structure directly or abutting a second underlying plate which rests on the support structure. Ordinarily, the track and underlying plates on which the rail rests are secured to the support structure by bolts or other clamping arrangements. In certain clamping arrangements of this sort, as exemplified by U.S. Patent No. 3,784,097, the clamps take the form of clips having a load bearing surface which mate to and overlie the lower rail flange and are secured to an underlying plate by means of bolts. Serrations may be provided in the top surface of the track plate for receiving a projection of the clip to permit lateral adjustment of the clip while limiting horizontal or sideways movement of the clip and rail. Such fasteners are limited to attaching rails that are perpendicular to the longitudinal axis of the track plate or are spaced apart to accommodate separate fasteners for each rail. Sufficient distance between the rails is required to accommodate the track plate of the individual fasteners. However, rails are not always perpendicular to the track plate and in other cases, the rails are spaced too close together to allow for separate fasteners for each rail. Furthermore, two non parallel rails may require support on one track plate. Such rails are generally found in systems used to switch trains from one set of rails to another including crossings, switches, frogs and the like. Conventional fasteners may be used in switches on converging rails until the rails are too close together to allow for individual fasteners to be placed under each rail. Although the fasteners as described are adjustable along the longitudinal axis of the track plate, they fail to provide angular adjustment for nonperpendicular positioning of the rail to the track plate. That is, if other than a substantially perpendicular relationship exists between the rail and the track plate, the load bearing surface of the clips will not fully engage the bottom flange of the rail. In other cases where the rails are spaced too close together such that the usual rail fasteners can not be used for each rail. Hence it is desirous to have a rail fastener that can accommodate lateral and angular adjustments as well as close spacing of rails. A commercially available product overcoming some of the above described problems is an adjustable special track fastener sold by Lord Corporation, assignee of the present patent. The special track fastener includes a long flat rectangular track plate for attachment to the flanges of more than one rail and has an elastomeric member bonded the length of the track plate on the side opposite to the rail contact side for isolating and damping vibration of the track fastener. Combination of the long track plate and elastomeric member allows for positioning the plurality of rails along the longitudinal length of the track plate. Vertical serrations extend along each of the longitudinal edges of the track plate and are adapted to cooperate with fastener assemblies for securing the plurality of rails to the track plate. The fastener assemblies include a clamping member overlying the flange of each rail and a threaded nut having mating vertical serrations thereon engagable with the serrations along the longitudinal edges of the track plate. The clamping member overlies the nut and has a load bearing surface engagable with the flange of the associated rail. A bolt extends through the clamping member and is threaded into the nut for securing the clamping member to the nut while securing each rail against horizontal movement. The fastener assembly may be located or adjusted along the longitudinal length of the track plate by virtue of the mating of the vertical serrations of the nut and the track plate. By virtue of the fact that the clamping member may rotate above the aforesaid bolt, it can be used to positively engage the rail along its length regardless of the angular attitude of the rail with respect to the plate. Such rotation provides angular adjustment of the clamping member to positively engage the rail along its length at nonperpendicular displacement of the rail with respect to the track plate. Furthermore, the clamping member of the fastener assembly has elongated bores therethrough for the bolts to accommodate the varying distances between the bolts resultant from the angular adjustment of the clamping member. The distance between the bolts is shortest when the rail is perpendicular to the track plate and the distance increases with the nonperpendicularity of the rail. While the described special trackwork fastener satisfactorily fastens closely spaced or nonparallel rails, hereinafter referred to as special rails, problems have arisen in using the fastener. One problem area is the adaptation of the special trackwork fastener to various separation widths between the rails. As one can imagine, widths between the rails will vary based on the point of convergence of the rails. Such separation widths may vary from about 2.54 cm (1 inch) to about 30.5 cm (12 inches). Using a long special trackwork fastener for a short separation results in much of the special fastener being unused. Varying the length of the special trackwork fastener requires manufacturing using various molds corresponding to the length of the fasteners. The resiliency properties of the special trackwork fastener are less desirable than the regular single pad under a single rail. Bonding of rubber to the full length of the track plate results in a very stiff fastener, increasing the spring rate of the elastomeric member underneath the rail and decreasing the flexibility of the fastener. Also, bonding of the rubber to the full length of the track plate is more expensive and difficult than for single pads. Various costly large molds are required to make the special fasteners. Serrations along the longitudinal edges of the track plate also increase the cost of the fastener. The elastomer member of the aforesaid special trackwork fastener may require replacement after a period of time due to normal wear or upon failure. Replacement of the elastomeric member of the special trackwork fastener as described requires replacement of the entire fastener even though a limited portion of the fastener needs replacement. In summary, although the special trackwork fastener is capable of fastening special rails, various undesirable features are inherent in the product. US-A-3858804 describes a rail fastener assembly which is adjustable, so that the rails may be set to a desired gauge. With the foregoing in mind, the present invention provides from one aspect, an improved rail fastener particularly suited for connecting special trackwork such as switches, crossovers and guardrails (hereinafter referred to as special rails) to a support structure. Thus the present invention consists in a rail fastener for attaching at least two closely spaced rails to a support structure including a fastener pad which has a rigid plate and a resilient member bonded to said rigid plate, and means to secure each of said rails in a position fixed relative to said support structure, said rail fastener being characterised by a rigid elongated track plate positioned between said fastener pad and said rails; said rigid plate of said fastener pad being bonded to an upper surface of said resilient member such that said resilient member engages said support structure and said rigid plate receives said elongated track plate, a separate fastener pad which is laterally adjustable relative to said track plate being provided for each said rail; said elongated track plate having a longitudinal axis which extends in a direction which is generally transverse to said rails and is of sufficient longitudinal extent to underlie each of said rails; said means to secure each of said rails including a plurality of fasteners received in elongated orifices which permit both lateral and angular adjustment of said rails relative to said track plate, such that one or more of said at least two rails may be positioned in directions which are not orthogonal to said track plate. The objects, features and advantages of the present invention should become apparent from the following description of the preferred embodiment when taken in conjunction with the accompanying drawings in which: Figure 1 is a top or plan view of an example of a track installation with which the present invention may be employed; Figure 2 is a top view of one embodiment of the invention showing two non-parallel rails fastened with clamping members to the track plate; FIG. 3 is a partial cross-sectional view taken along the line 3-3 of FIG. 2 showing the track plate and a fastener pad disposed underneath the rail; FIG. 4 is a partial cross-sectional view of the rail fastener taken substantially along the line 4-4 of FIG. 3. Referring now to the drawings, FIG. 1 shows a typical track installation with which the present invention may be used. It includes a switch section 10, a straight rail section 11 and a frog section 12. In the straight rail section 11, the rails are secured to underlying support structure such as concrete, by fasteners 13 which include an upper plate secured to the rails by suitable laterally adjustable clamping devices. Ordinarily, the fasteners 13 are provided with an underlying elastomer layer which abuts the underlying support surface directly or abuts a second underlying plate which rests on the support surface. Such fasteners are suitably used for straight sections of rails wherein the fastener and components thereof are square with the flange of the rail and can be used for converging rails at frogs or switches wherein the rails are sufficiently spaced to accommodate separate fasteners for each rail. Typical fasteners for rapid transit systems of this type are described in U. S. Patent No. 3,576,293. In the switch section 10 and the frog section 12, however, it will be appreciated that there are areas where two rails 15a, 15b converge or are located close together wherein single fasteners 13 cannot be located under individual rails 15a, 15b. Rather, rail fasteners 16 according to the present invention extending under closely adjoining rails are used for this purpose. Rail fasteners 16 include a rigid track plate spanning at least two rails, a plurality of adjustably spaced, discrete fastener pads, each joined to the track plate in an underlying relation to respective rails, and a means to join each rail to the track plate. One embodiment of the present invention is shown in FIGS. 2-4. In particular, FIG. 2 shows the orientation of two rails 15a, 15b to the rail fastener 16. The two rails 15a, 15b are in close proximity as would be found in a switch section 10. Rail 15b extends at right angles to the rail fastener 16 whereas rail 15a is not parallel to rail 15b, being disposed at an angle of about 10° from a line perpendicular to the rail fastener 16. Such angle displacements may range up to about 20° from a line perpendicular to the rail fastener 16. Each rail 15a, 15b has an upper portion 31, web 33 and a flange 35 of which the upper portion 31 and flange 35 are shown in FIG. 2 and the web 33 is intermediate thereof. As best seen in FIG. 3, the rail fastener 16 has a rigid track plate 17, a fastener pad 20 removably secured to the rigid track plate 17 and a fastener assembly 30 to secure the rail 15a to track plate 17. The rigid track plate 17 is a substantially flat elongate rectangular steel plate extending under and beyond the flanges 35 of both rails 15a, 15b. Located near each longitudinal end of the track plate 17, (one shown in FIGS. 2 and 3) is a bolt 28 and clamp 27 to secure the track plate 17 to the support structure 26 preventing undesirable lateral, longitudinal or vertical movement thereof. As shown in FIG. 3, the support structure 26 is concrete. A mating member 28a to the bolt 28 is secured in the support structure 26. The bolt 28 extends through an orifice in the clamp 27, an orifice in the track plate 17 and an orifice in a fastener pad 29 disposed between the track plate 17 and support structure 26 and is threadedly engaged with the mating member 28a. Clamp 27 and elastomer member 29 allow the track plate 17 to deflect in response to applied forces thereby reducing vibration and noise. Furthermore, a series of orifices 19 extend through and are located along the longitudinal axis of the plate 17 for joining the elastomeric member 20 to the top plate 17. Each fastener pad 20 is an integral unit made up of a flat rectangular rigid steel plate member 21, a pair of steel pins 22a, 22b and a resilient member 23 affixed to the rigid member 21. The rigid member 21 has an upper surface mating against the bottom of the track plate 17 when assembled, and is sufficiently long to extend beyond the two longitudinal sides of the track plate 17 as shown in FIGS. 2 and 4. The opposite longitudinal edges of the rigid member 21 are provided with vertical serrations 25 along substantially their entire length as shown in FIG. 2. These serrations cooperate with fastener assemblies 30 to secure each rail 15a, 15b to the rail fastener 16. See FIG. 4. Orifices 21a extend through rigid member 21, spaced from each other and sized to mate with the orifices 19 of the top plate 17. Corresponding pins 22a, 22b extend through the respective orifices 21a and fit into the aligned orifice 19 of the top plate 17. Each pin 22a, 22b has a head portion 22a′, 22b′ which abuts the flat surface of the rigid plate 21. The pins 22a, 22b are assembled in the respective orifices 21a prior to the bonding of the resilient pad to the rigid member 21. The resilient member 23 is made of elastomer suitable to isolate and dampen vibrations as well as to electrically insulate each rail 15a, 15b which may carry electrical signals, from ground. As is well known, the elastomer section allows the track plate 17 to deflect in response to force applied to the rail 15a, 15b, which reduces vibration and noise. The pad 23 is bonded to the rigid members 21 by a suitable elastomer to metal adhesive. An outer peripheral lip of the rigid plates extends beyond the resilient member 23 to provide a surface area to clamp the fastener pad 20. According to the present invention, each rail 15a, 15b is adjustably secured to the rail fastener 16 at the desired angular and lateral relationship by the fastener assemblies 30. Referring to FIGS. 3 and 4, each fastener assembly 30 includes a rectangular upper clamping plate 32, two bolts 36 each with a cooperating lower nut 38. The upper clamping plate 32 extends across and beyond the track plate 17 adjacent the rail flange 35 and has a projection 34 having a load bearing tapered surface overlying the flange 35 on the corresponding rail to hold it vertically and horizontally. Each clamping plate 32 has two elongated orifices 32a, one located at each longitudinal end thereof beyond the side of the track plate 17 through which the bolt 36 extends. The bolt 36 threadedly engages the lower nut 38. A gap 38a exists between the upper clamping plate 32 and the lower nut 38 to allow tightening across the two members. Nut 38 is provided with serrations 40 along one edge and has a threaded opening 42 into which the bolt 36 is threaded. Serrations 40 engage in a meshing relationship with the serrations 25 on an edge of the plate 21. Beneath the serrations 40 on each nut 38 is a perpendicular projection 44 which fits the underside of the lip 24 of rigid plate 21. This arrangement allows for rotation of each clamping plate 32 relative to the track plate 17 yet maintaining the interfacing of the load bearing tapered surface on the flange 35. Returning to Figure 2, one can see a top view of how the rail fastener 16 is suitable to clamp rails at various spacings and at various angles to the longitudinal axis of the rail fastener 16 . Located between the support structure 26 (not shown) and the track plate 17 for each rail 15a,15b is the fastener pad 20 of which the serrated sides 25 of the rigid member 21 are shown extending beyond the sides of the plate 17. Each pad 20 is oriented square to the plate 17. The flange 35 of the rails 15a,15b are clamped to the track plate 17 by fastening the clamping plates 32 to the elastomeric member 20. The clamping plates 32 are oriented parallel to the flange 35 of the rails 15a,15b . For rail 15b, extending perpendicular to the track plate 17, the clamping plates 32 are accordingly perpendicular to the track plate 17. Bolts 36 extending through the elongated orifices 32a to threadingly engage the nut 38. When the bolt is tightened, the rail 15b becomes securely clamped in place to the track plate 17. The distance between the two bolts 36 is shortest when the clamping plate 32 is perpendicular to the track plate 17. As shown in Figures 3 and 4 and in conjunction with the foregoing description, each pad 20 can be laterally positioned along the longitudinal axis of its respective track 15a,15b by suitably positioning the clamping plate 32, bolts 36 and the nut 38 such that the serrations 40 of the nut 38 and serrations 25 of rigid member 21 align. Rail 15a is not parallel to rail 15b but extends at about an angle of 10° therefrom. As with rail 15b, the clamping plates 32 are oriented parallel to the flanges of rail 15a, thereby at an angle of about 10° from the plane perpendicular to the track plate 17. Such an angular orientation results in an increase in distance between the bolts for each clamping plate 32. The elongated orifices 32a allow for the increased distance. Bolts 36 are then extended through the orifices 32a and threadingly engaged with a corresponding nut 38. The serrations 40 and projection 44 of the nut 38 remain square with the respective serrations 25 and lip 21a of the fastener pad 20. Rail 15a can be clamped by tightening the bolt 36 accordingly. A feature of the present invention is having fastener pad 20 that may be positioned underneath each special rail to result in maximum benefit of the resilient member in isolating and damping vibratory motions of the rail. Each fastener pad 20 is positioned underneath the top rigid plate 17 by mating the extending pins 22a, 22b of each pad 20 with two of the series of the mating orifices 19 of the track plate 17. Once the location of the rail 15a on the track plate 17 has been determined, the fastener pad 20 may be joined to the top plate 17 so that the resilient member 23 of the fastener pad 20 is positioned between the rail 15a and the support structure 26. Furthermore, when replacement of the fastener pad 20 is required, the member 20 can be removed from the track plate 17 and easily replaced. The entire special trackwork fastener of prior art had to be completely removed and replaced upon replacement of the elastomeric pad. Also, the rail fastener 16 of the present invention is easily manufactured requiring only one mold for the fastener pad 20, regardless of the spacing or angle of the rails to the fastener. In manufacturing the prior art special trackwork fastener the entire assembly was molded with the rubber member. In the present invention, the top plate is separately manufactured and only the smaller elastomeric pad 20 requires molding. Furthermore, the number of serrations are greatly reduced, providing more advantages. While the invention has been described with reference to two embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teaching of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.

Claims: A rail fastener (16) for attaching at least two closely spaced rails (15a,15b) to a support structure (26) including a fastener pad (20) which has a rigid plate (21) and a resilient member (23) bonded to said rigid plate (21), and means (30) to secure each of said rails (15a,15b) in a position fixed relative to said support structure (26), said rail fastener (16) being characterised by a rigid elongated track plate (17) positioned between said fastener pad and said rails; said rigid plate (21) of said fastener pad (20) being bonded to an upper surface of said resilient member (23) such that said resilient member (23) engages said support structure (26) and said rigid plate (21) receives said elongated track plate (17), a separate fastener pad (20) which is laterally adjustable (19,22a,22b) relative to said track plate (17) being provided for each said rail; said elongated track plate (17) having a longitudinal axis which extends in a direction which is generally transverse to said rails (15a,15b) and is of sufficient longitudinal extent to underlie each of said rails (15a,15b); said means (30) to secure each of said rails (15a,15b) including a plurality of fasteners (36) received in elongated orifices (32a) which permit both lateral and angular adjustment of said rails (15a,15b) relative to said track plate (17), such that one or more of said at least two rails (15a,15b) may be positioned in directions which are not orthogonal to said track plate (17). The rail fastener of Claim 1 being further characterised by said rigid plate (21) having vertical serrations (25) extending along the longitudinal edges thereof and said means (30) to secure said rails (15a,15b) to said track place (17) including a threaded nut (38) which has serrations (40) thereon which are adjustably engageable with said serrations (25) of said rigid plate (21). The rail fastener of Claim 2 being further characterised by a clamping member (32) overlying said nut (38) and engageable with an associated rail, and bolt means (36) threaded into said nut (38) for securing said clamping member (32) to said nut (38) for securing said rail against horizontal movement. The rail fastener of Claim 3 being further characterised by said clamping member (32) being rotatable about said nut (38) for securing a rail to said track plate (17) at any desired angular relationship with respect to the longitudinal length of said track plate (17). The rail fastener according to any of the preceding claims being further characterised by said track plate (17) having a plurality of orifices (19) therethrough, means to secure said resilient member (23) to said track plate (17) including a pair of pins (22a,22b) extending from said resilient member (23) mateable with a pair of said plurality of orifices (19).

Inventors: SHERRICK JAMES W, SHERRICK, JAMES W.
Applicants: LORD CORP, LORD CORPORATION
Application year: 1989
Main classification: E01B9
IPC codes: E01B9