Railway ail fastening assembly and method

A fastening system or apparatus for securing a rail to the underlying railroad tie includes a pad, two insulators attached to the pads and two shoulders attached to the ties. An interference fit is formed between the insulators and the shoulders to capture the pad between the shoulders. The insulators are pre-attached to the pad. The mating protrusions of the shoulders and pad allows for ease of insertion such that the pad assembly can be shipped together with the underlying tie.

RELATED APPLICATIONS

BACKGROUND OF THE INVENTION

A. Field of Invention

This invention pertains to a rail support assembly for supporting the rails of a railroad track. The assembly includes shoulders preferably attached or mounted on a precast concrete tie and a pad disposed on top of the tie and captured between the shoulders so that the whole assembly can be stored and shipped to a track installation/repair site as a single unit.

B. Background of the Invention

Generally speaking, the present invention pertains to the art of securing the rails forming railroad tracks to transversal ties. Typically, a rail support assembly is used that includes a pair of shoulders, somewhat flexible clips engaging the shoulders and shaped to secure the lateral flange of the rail to the tie and a generally electrically insulating pad. The pad is positioned between the two shoulders and under the rail. The elements of rail support assembly are often tied together and shipped to the installation site. For some types of railroads, for example light rails, the shoulders are imbedded into the ties as they are being cast, for example, from concrete and thus are not transported to the site together with the rest of the elements of the support assembly. As a result, the rest of the assembly or some parts thereof, can easily separate, get lost, or stolen. Thus, shipping and installing these support assembly create a logistic and economic nightmare.

It has been suggested by some references (see for instances, U.S. Pat. Nos. 6,367,704 and 7,669,779) that the assembles be provided that used captive elements. The assemblies are attached to the shoulders together with the clips to the ties prior to their shipping. However, the previously suggested concepts were only useable with split clips and not with convoluted or S-shaped clips that are now used almost universally. Moreover, the suggested solutions required elements with complex shaped that are difficult and expensive to make; required a complex installation requiring the use of a heavy hammer; and required the rail clip to be part of the assemblies to hold the rail pad in place.

SUMMARY OF THE INVENTION

According to the present invention there is provided a railway rail fastening assembly for fastening a railway rail to an underlying rail foundation (e.g., a cast concrete tie). The assembly includes two railway shoulders. Each shoulder is formed with a protrusion on the rail facing. A pad is sized and shaped with or attached to two lateral insulators. The insulators have lateral sides for mating with the posted pad assembly; the pad assembly comprising of either a single or composite pad and insulator; where the insulators face the shoulders and having protrusions or ribs mating with groves on the shoulders to retain pad in a captive position. The protrusions on the insulators also serve as seals or covers against dirt and debris—runoff in between insulator and/or pad and shoulder and/or rail seat. Additionally, the insulator protrusions are angled to guide the rail into the rail seat area aiding the process of placing the rail into the rail seat, further having the posted pad assembly allows the dunnage to be reduced by an amount equal to the pad thickness plus the compression amount of the pad due to external forces to the system such as crosstie stack height, storage temperature, etc.; the pad assembly is being held captive in the assembly against unintentional removal from the rail seat whereby the pad is pre-attached to the side post insulators located in a mirror image of each other with the pad in the middle, and the pad is of preferably of a softer material to attenuate rail seat loads and the insulators in a stiffer material to resist rail seat lateral loads and together the pre-attached, insulators and pad, represents the posted pad assembly of which they together electrically insulates the rail from the underlying foundation, the said insulators are pre-attached to the pad, preferably overmolded, as an assembly of which can be hand-inserted or utilizing a 0.5″ or higher gravity drop of posted pad assembly into the rail seat. The gravity drop requires the posted pad assembly to be centered above the rail seat to within a 0.25″. The mating protrusions of the shoulders and posted pad allows for ease of insertion and so that the posted pad assembly can be shipped together with the underlying foundation. The preferred method to remove the posted pad assembly, from inserted and captive position, is to compress the pad slightly, preferably, against either of the two shoulders in order to vertically disengage the shoulder and insulator protrusions from each other; the rail clip, preferably with a pre-attached electrically insulating plastic toes installs into the shoulders, after rail has been put in the rail seat, to fasten the rail on the pad and in between the two insulators whereby the clip bears against the base of the rail and anchored to the shoulders that are secured by embedment into underlying foundation; a clip is not required to retain the pad assembly in pre-assembly position. The clip used with the assembly preferably has a plastic toe pre-attached electrically insulating the clip from the rail.

DETAILED DESCRIPTION OF THE INVENTION

Referring now toFIG. 1a railroad assembly10constructed in accordance with this invention includes a rail12having a foot14with two sections14A,14B. The rail12is supported on a tie16by a fastening assembly18.

Fastening assembly18includes a pad20, and two shoulders22,24. The two shoulders22,24are imbedded in a conventional concrete tie25. The rail12is secured to the fastening assembly18by two conventional clips, such as e-clips available from Pandrol. These clips have been omitted from the figures for the sake of clarity.

As shown inFIGS. 2A-2D, the pad20includes a generally rectangular central portion30with a top surface32and a bottom surface34. Both surfaces32,34are formed with a plurality of circular indentations36as shown. The central portion includes two longitudinal sides38,40. These sides are sized and shaped to mate with two insulators42,44. In one embodiment, the insulators42,44are made separately and joined to the central portion30by an interference fit and/or by an adhesive. In one embodiment, the two insulators42and44and the central portion30are a single piece made by molding or other well known-techniques.

The central portion30and insulators38,40are sized and shaped to insure that two vertical inner surfaces46,48of the insulators are oriented perpendicularly to the top surface32and in parallel to each other and are separated by a distance W. W is also width of the foot14so that when the rail12is placed on the pad20it fits snugly between walls46,48, as shown inFIG. 1.

As shown more clearly inFIGS. 3A, 3B, insulator44is formed with a generally vertical body50and a wing52. The wing52is formed so that it leans or extends away from wall48. Wing52terminates with a horizontal profiled edge54.

Insulator44is also formed with an outer vertical wall56disposed below and inwardly of profiled edge54.

Insulator42similarly has an inner vertical wall46(discussed above), an outer vertical wall60and a horizontal edge62disposed on a wing64(seeFIGS. 5, 5A).

Referring toFIG. 4, shoulder24is formed with a leg70extending downwardly as shown. The leg70is connected to and is integral with a body72. Body72is formed with a round horizontal bore74. The body72further includes an external surface76formed with a lip77and an external horizontal groove78disposed below lip77. Below grove78there is a vertical wall80. Grove78is sized and shaped so that it is complementary to edge62. Shoulder22has the same shape as shoulder24.

The fastener assembly18is produced as follows. First, the concrete tie16is formed in a conventional manner. As part of this step, the shoulders22,24are imbedded in the tie so that their legs70are completely disposed within concrete and only the bodies72are exposed, as shown inFIGS. 1 and 5. It should be noted that two sets of shoulders are used, on a tie, one for each rail.

The pad20with insulators44,46are created independently of the tie16. As discussed above, the pad20are either formed simultaneously with the insulators42,44, or separately. If the second technique is used, then the insulators42,44are then attached to the pad20along sides38,40.

Note that the various components described above are sized and shaped so that when the pad20with its insulators42,44are assembled the distance between the outer vertical walls56,66are the same or just slightly less than the distance between the inner vertical walls80of the shoulders22,24. However the wings52,64with their edges54,62extend outwardly of these vertical walls. As a result, if the pad20with the insulators42,44is placed above of the shoulders, edges54,62rest on top of lips77, as seen inFIG. 5A.

In order to attach the pad20and insulators22,24(forming a pad assembly90) to the tie16, the pad20is dropped from about 0.25-0.5 inches As the pad assembly is falling, as indicated by arrow A inFIG. 5A, the bottom surfaces of the edges54,62come into contact with the lips77. The insulators42,44, or at least their wings are sufficiently elastic so the wings52,64flex slightly inward until they clear the lips77, and the edges65,62then snap into grooves78. In this manner, the pad assembly90is secured or captured between the shoulders22,24, as shown inFIGS. 1 and 5, but of course, without the rails12. The pad assembly and the shoulders are thus held together by an interference fit between the wing edges of the insulators and the grooves of the shoulders. If necessary, the pad assembly can be separated from the shoulders by bending one or both wings inwardly and then placing a sharp object between the pad20and the tie16and forcing the pad20upward until the insulators disengage from the grooves in the shoulders.

The tie with the shoulders22,24and the pad assembly90is now ready to be stored or shipped out to the field. The ties with the pad assembly and the shoulders are placed in position, the rails12are placed on the ties, as shown inFIG. 1, and conventional clips (not shown) are inserted into the holes74to fasten the rails down.

In an alternate embodiment, the shoulders are made with profiled edges to fit into matching groves in the insulators.

Obviously, numerous modifications may be made to this invention without departing from its scope as defined in the appended claims.