The present invention relates to the field of rail pad assemblies for railway systems that have concrete rail ties.
Railway systems commonly seat a metal rail upon a concrete rail tie via the use of a rail pad assembly. Within a rail pad assembly, there is often a plurality of components. In one example, a rail pad assembly includes a rail pad and a protective sheet. In the past, there have been some efforts to attach a rail pad assembly to a rail tie. It is to be appreciated that having the rail pad assembly attached to the rail tie can provide for ease of handling, etc. during transport, installation, etc.
In the past, it has been a common practice to utilize adhesive tape, and specifically double sided adhesive tape to secure rail pad assemblies to concrete ties. Such an approach has several detractions. One example of such a distraction is that the aspect of providing the adhesive tape is rather labor intensive. Also, it is possible that the adhesive tape will not provide sufficient adhesion. Still further, if it is ultimately desired/beneficial to use the adhesive tape for transportation and not have the tape present during final installation of the concrete tie and associated rail pad assembly within a railway system, the tape must be removed.
Another example of a past device is a Pandrol Lock-in Pad (available at http://www.pandrol.com/cstudies/c25_fr.htm). This device has tabs on a rail pad that extend into recess pockets within cast-in-place shoulder components on a rail tie. This device relies upon the pockets being provided in the shoulder components to receive the tabs. It is noted that this device intentionally does not have an interference fit since the tabs are designed to extend under portions of the shoulder components that define the pockets for positive locking. So long as both tabs are present and nothing obscures or blocks the pockets, the tabs can provide a holding mechanism. Unfortunately, if the shoulder components are not positioned properly on the tie (e.g., cast in too low or too high, the rail) pad assemblies may encounter retainment issues. Also, retainment issues may arise if concrete or debris fills the pockets.
Other structures have been tried and are shown in U.S. Pat. Nos. 4,971,247 and 7,100,837. With regard to U.S. Pat. No. 4,971,247, in one embodiment (see face sheet and
Such projections are logically constructed to be rather small because the tabs are either for location purposes or are located with a notch. The notch provides bearing surfaces for bearing against the clip-retainer member or the shoulder component so that the pad does not significantly move when the rail pad is finally installed and subjected to cyclic loading as a train passes. As such, there is a need for improvements in this area. Specifically, there is a need for an improved design of a rail pad that can retain the rail pad or rail pad assembly during shipping/transportation without interfering with the primary and long term functions of the rail pad, including movement prevention caused by cyclic loading.
In accordance with one aspect, the present invention provides a rail pad assembly for use with a rail tie that has a pair of rail retainer shoulder components that oppose each other for receiving the rail pad assembly onto the rail tie upon a relatively downward vertical movement of the rail pad assembly into engagement with the rail tie. Each shoulder component has a center projection portion and two stepped-back side portions that have laterally-outwardly sloped face surfaces adjacent to the center projection. The rail pad assembly includes a rail pad for engagement with a rail and a protective member extending between the rail pad and the rail tie. The rail pad includes two notches formed at laterally-opposed ends of a body of the rail pad for mating with the center projections of the shoulder components by the center projections extending into the notches when the rail pad assembly is received onto the rail tie. Each notch has a face surface and two side surfaces that conform in shape and position to respective face and side surfaces of the center projection portion of the shoulder component such that with the rail pad assembly received onto the rail tie the rail pad is constrained against translational movement. The rail pad includes flexible projections that extend out away from the body of the rail pad in lateral directions. Each projection is located adjacent to one of the notches on the rail pad such that each flexible projection engages the laterally-outwardly sloped face surface of a respective one of the stepped-back side portions of the shoulder components as the rail pad assembly is moved vertically downward toward the rail tie and nears a final position in engagement with the rail tie. The flexible projections have a construction such that the flexible projections are resiliently deflected relatively upward during the relative downward vertical movement of the rail pad assembly subsequent to engagement between the flexible projections and the face surfaces of the stepped-back side portions and as the rail pad assembly settles into the final position in engagement with the rail tie to wedge the rail pad between the face surfaces of stepped-back side portions and retain the rail pad assembly onto the rail tie.
In accordance with another aspect, the present invention provides a rail pad assembly for use with a rail tie that has a pair of rail retainer shoulder components that oppose each other for receiving the rail pad assembly onto the rail tie upon a relatively downward vertical movement of the rail pad assembly into engagement with the rail tie. Each shoulder component has a center projection portion and two stepped-back side portions that have laterally-outwardly sloped face surfaces adjacent to the center projection. The rail pad assembly includes a rail pad for engagement with a rail and a protective member extending between the rail pad and the rail tie. The rail pad includes two notches formed at laterally-opposed ends of a body of the rail pad for mating with the center projections of the shoulder components by the center projections extending into the notches when the rail pad assembly is received onto the rail tie. Each notch has a face surface and two side surfaces that conform in shape and position to respective face and side surfaces of the center projection portion of the shoulder component such that with the rail pad assembly received onto the rail tie the rail pad is constrained against translational movement. The rail pad includes projections that extend out away from the body of the rail pad in lateral directions. Each projection is located adjacent to one of the notches on the rail pad such that each projection engages the laterally-outwardly sloped face surface of a respective one of the stepped-back side portions of the shoulder components as the rail pad assembly is moved vertically downward toward the rail tie. Each of the two side surfaces of each notch is located on a portion of one of the projections. Each projection has a portion that tapers to thin as the projection extends in a direction laterally away from the body of the rail pad.
In accordance with yet another aspect, the present invention provides a rail pad assembly on a rail tie that has a pair of rail retainer shoulder components that oppose each other for receiving the rail pad assembly onto the rail tie upon a relatively downward vertical movement of the rail pad assembly into engagement with the rail tie. Each shoulder component has a center projection portion and two stepped-back side portions that have laterally-outwardly sloped face surfaces adjacent to the center projection. The rail pad assembly includes a rail pad for engagement with a rail and a protective member extending between the rail pad and the rail tie. The rail pad includes two notches formed at laterally-opposed ends of a body of the rail pad and mating with the center projections of the shoulder components by the center projections extending into the notches with the rail pad assembly received onto the rail tie. Each notch has a face surface and two side surfaces that conform in shape and position to respective face and side surfaces of the center projection portion of the shoulder component such that with the rail pad assembly received onto the rail tie the rail pad is constrained against translational movement. The rail pad includes flexible projections that extend out away from the body of the rail pad in lateral directions. Each projection is located adjacent to one of the notches on the rail pad such that each flexible projection is engaged with the laterally-outwardly sloped face surface of a respective one of the stepped-back side portions of the shoulder components, the engagement having occurred during movement of the rail pad assembly vertically downward toward the rail tie. The flexible projections are resiliently deflected relatively upward, the resilient deflection having occurred during the relative downward vertical movement of the rail pad assembly subsequent to engagement between the flexible projections and the face surfaces of the stepped-back side portions and as the rail pad assembly settles into the final position in engagement with the rail tie. The resiliently-deflected flexible projections engaged with the face surfaces of the stepped-back side portions wedge the rail pad between the face surfaces of stepped-back side portions and retain the rail pad assembly onto the rail tie.
The foregoing and other aspects of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:
It is to be appreciated that the following descriptions of example embodiments are not intended to present overall limitations on the present invention and are merely provided for illustrative purposes. It is to be appreciated that the present invention contains broader concepts than as presented within the following simplistic example embodiments and that the broader aspects are to be considered as part of the present invention.
As seen in
Each of the two retainer assemblies 30A, 30B has a shoulder component 32A, 32B, which may be made of metal such as cast iron. The two shoulder components 32A and 32B are secured to the rail tie 8. In one specific example, as the rail tie 8 is cast, the shoulder components 32A and 32B are cast in place such that a portion of each shoulder component 32A, 32B is embedded (hidden) into the concrete and a portion of each shoulder component 32A, 32B extends out of the rail tie, generally as shown within
The shoulder components 32A and 32B are generally identical and as such the shoulder components are described generically with the understanding that the description applies to both shoulder components. The same references numbers are used for both shoulder component 32A and 32B. Each shoulder component (e.g., 32A,
The center projection portions 34 of the shoulder component 32A and 32B face each other. Specifically, face surfaces 38 on the center projection portions 34 are opposed to each other across the space in which the rail pad assembly 10 and the rail 6 are located. Also, the face surfaces 42 on the stepped-back side portions 36 are respectively opposed to each other across the space in which the rail pad assembly 10 and the rail 6 are located. The center projection portion 34 does extend further toward the opposed, other shoulder component than the stepped-back side portions 36. Thus, the stepped-back side portions 36 can be considered to provide two shoulders with reference to the center projection portion 34. Each face surface 42 of the stepped-back side portions 36 slopes laterally-outward, away from the space that contains the rail pad assembly 10 (
It is to be appreciated that each shoulder component (e.g., 32A) provides a point of attachment or anchor for one or more fasteners, such as a spring clip 44 that is part of the respective retainer assembly (e.g., 30A). Such spring clips 44 are generally well known within the rail system industry, especially concerning the rail system industry directed to the use of concrete rail ties. In short summary, the spring clips 44 secure the rail 6 on top of the rail pad assembly 10. In one example, the spring clips 44 are made of spring metal. Such fasteners are often referred to as rail clamps. It is to be appreciated that many types of fasteners can be used with the subject invention. Also, the shown example has an insulator member 46 within each retainer assembly (e.g., 30A) located between the spring clip 44 and the rail 6. The insulator member 46 is made of insulating material, such as electrically insulating material.
It is to be appreciated that the materials and general constructions of the retainer assemblies 30A and 30B, and the rail tie 8 are not specific limitations on the present invention. However, the shoulder component configuration is of particular interest because it is this configuration the present invention utilizes to provide a unique solution to retaining the rail pad assembly 10 onto the rail tie 8, and yet not interfere with the long term functions of the rail pad assembly.
It is desirable and/or useful to have the rail pad assembly 10 remain in position/in engagement with the rail tie 8 and the shoulder components 32A and 32B during pre-assembly, transport, movement, etc. As such, and in accordance with one aspect of the present invention, the rail pad assembly 10 includes means for retaining the position/engagement between the rail pad 12 and the rail tie 8. In one example method, the rail pad 12 can be attached to the rail tie 8 by the use of means for retaining the position of the rail pad. This also provides for the rail pad 12 to be attached to the rail tie 8 before the entire tie pre-assembly is shipped to the customer (e.g., a railway company). This pre-assembly can reduce installation time and cost. In the present example, such means for providing such functions is provided, at least in part by projection 56A-56D (
As shown in the example embodiment of
The flanges 58A-58D and thus the projections 56A-56D extend in lateral directions away from the body of the rail pad 12. The flanges 58A-58D and/or projections 56A-56D have several surfaces. These surfaces can have different shapes and/or configurations. These surfaces can be used as a locating feature for making assembly easier. The locating feature can be used to form registration between the shoulder components 32A and 32B and the rail pad assembly 10. These surfaces can also bearing surfaces for force transmission to prevent movement of the rail pad assembly 10 relative to the shoulder components 32A and 32B.
Turning to the shown example, each projection (e.g., 56A) can be considered to be the respective entire flange (e.g., 58A). As such, the term projection is simply used for discussion. Also, within the shown example, each projection (e.g., 56A) has generally identical structure to that of the other projections. As such, identical reference numbers are used and with the understanding that the description is applicable to all of the projections.
Again with reference to the shown example, the projection (e.g., 56A) has an inner surface 62 that is generally planer and an outer surface 64 that is generally planer. The two projections (e.g., 56A and 56B) on a lateral side of the rail pad 12 define a notch 66 there between. The notch 66 has a most recessed face surface 68, which is the surface furthest into the notch. The notch 66 also has two side surfaces, which in this example are the same surfaces 62 as the surfaces of the projections (e.g., 56A and 56B). As such the projections (e.g., 56A and 56B) are immediately adjacent to the notch 66. It is to be noted that the surfaces 62 of the projections (i.e., the side surfaces of the notch) are connected to the face surface 68 of the notch 66 via two curved surface segments 70. Of course, different surface patterns/configurations are possible.
The surface patterns/configurations are designed so that the center projection portion 34 of the shoulder component mates into the respective notch 66 with a fairly close relationship. In such a mated relationship, the projections (e.g., 56A and 56B) lie close to the side surfaces 40 of the center projection portion 34. Accordingly there is a conformance in shape between the center projection portion 34 and rail pad 12. Thus, the rail pad 12 is entrapped against transverse movement by the two shoulder components 32A and 32B of the retainer assemblies 30A and 30B. The entrapment results in a constraint against translational movement of the rail pad 12.
Turning back to details of the projections within the shown example, each projection (e.g., 56A) has a maximum thickness, as measured vertically, which is not greater than the maximum thickness, as measured vertically, of the body of the rail pad 12. Also in the shown example (see
It is to be appreciated that the projections 56A-56D are located adjacent to the notches 66 and the center projection portions 34 are to be located within the notches. As such, the projections 56A-56D are located to interact with the stepped-back side portions 36 of the shoulder components 32A and 32B.
To be clear, each projection (e.g., 56A) is located adjacent to one of the notches 66 on the rail pad 12 such that each flexible projection engages with the laterally-outwardly sloped face surface 42 of a respective one of the stepped-back side portions 36 of the shoulder component. The engagement occurs during movement of the rail pad assembly 10 vertically downward toward the rail tie 8. Specifically, as the rail pad assembly 10 nears a final position, the projections 56A-56D engage the laterally-outwardly sloped face surfaces 42 of the respective stepped-back side portions 36 of the shoulder components 32A and 32B. The flexible projections 56A-56D resiliently deflect relatively upward as the rail pad assembly 10 continues to move relatively, vertically downward subsequent to engagement between the flexible projections 56A-56D and the face surfaces 42 of the stepped-back side portions 36 and as the rail pad assembly is pushed down and settles into the final position in engagement with the rail tie 8.
The resiliently-deflected flexible projections 56A-56D engaged with the face surfaces 42 of the stepped-back side portions 36 wedge the rail pad 12 between the face surfaces of stepped-back side portions and retain the rail pad assembly 10 onto the rail tie 8. This wedging occurs without interference with the interaction between the center projection portion 34 and the notch 66 on the rail pad 12. Specifically, the center projection portion 34 can directly bear against the surfaces 62, 68 and 70 without a flexible portion interposed there between. Also, spacing concerns about being able to interpose a flexible portion in the area between the rail pad at the notch and the center projection portion do not exist. Such was a concern for prior rail pad designs. Thus, the surfaces 38 and 40 of the center projection portion 34 and the surfaces 62, 68 and 70 are constructed with a focus upon just the function of being bearing surfaces for transverse force transmission. During cyclic loading, which is caused by a train passing along the rail track, transverse forces pass directly between the bearing surfaces of the rail pad 12 and the center projection portion 34.
It can be appreciated that the wedging is very useful for transportation/shipping of the rail pad assembly 10 with the rail tie 8. Specifically, no external retaining means is needed to keep the rail pad assembly 10 on the rail tie 8. One example of a previously used retaining means includes double sided tape. However, the retaining function without interfering with other functions is beneficial. Also, the wedging with the laterally-outwardly sloped face surface of a respective one of the stepped-back side portions via the deflection of the projection is useful because spacing of bearing surfaces does not need to accommodate any additional portions of the rail pad such as space filler projections. Still further, the wedging with the laterally-outwardly sloped face surface of a respective one of the stepped-back side portions via the deflection of the projection makes use of easy arrangement and permits a greater tolerance of sizing non-conformity than merely a button-like projection. In addition, with the projection being next to the center projection portion of the shoulder component, the projection can provide the dual function of wedging and also providing additional bearing surface, without the bearing forces being solely transmitted through the flexible projection portion, as in some previous rail pad designs.
As still another possible feature, the protective sheet member 14 can have additional function concerning bearing upon the center projection portion 34 of the shoulder component (e.g., 32A) during transmission of transverse force between the rail pad 12 and the shoulder component. Specifically, since no room needs to be provided within the notch 66 to accommodate a projection that would extend within the notch to engage the center projection portion of the shoulder component, surfaces that define a corresponding notch 86 in the protective sheet member 14 can be identical or nearly identical to the surfaces that define the notch 66 in the rail pad 12. In other words, the two notches 66 and 86 are identical or nearly identical in size, and both can closely mate to the center projection portion 34. As an example,
Of course, it is to be appreciated that modifications are possible. For example, a different number, a different location, or a different configuration of the projections 56A-56D is possible within the rail pad assembly 10. For example, it is possible that two projections rather than four, possibly laterally disposed, may have sufficient retaining ability.
Turning to other details of the construction of the example rail pad assembly 10, the protective sheet member 14 is located below the rail pad 12. The protective sheet member 14 can be made of a tough and abrasion resistant material. The protective sheet member 14 can be mostly flat. However, the shown example presented within this embodiment has an outer peripheral raised lip 90 extending at least partially about the protective sheet member. This lip 90 provides a receiving area for the rail pad 12. Thus, the rail pad 12 is seated within and is partially surrounded by the lip 90.
It is to be appreciated that the protective sheet member 14 may be attached to the rail pad 12. In one example, such attachment is via a plurality of passageways or holes 92 that extend through the rail pad 12. The passageways 92 receive projections 94 on the protective sheet member 14. The projections 94 can be seen best in
With regard to the foam sheet 16, the sheet may be adhered to the bottom of the protective sheet member via several adhesive methods. However, one useful and efficient method is to use spray adhesive. The adhesive can be sprayed onto just a portion of the bottom surface of the protective sheet member 14 (e.g., much less than the entire bottom surface).
Also, as mentioned the present example rail pad assembly 10 includes the insulator member 46 that is located between the spring clips 44 and the rail 6. The insulator member 46 also has a portion that extends between the rail 6 and the shoulder component (e.g., 32A). In order to accommodate the insulator member 46 at this portion and/or to prevent movement and possible loss of the insulator member, the example rail pad 12 includes a stepped-in recess 98 that is open to the notch 66. The insulator member 46 is received within the stepped-in recess 98. At least a portion of the face surface 68 of the notch 66 is located below the stepped-in recess 98. With such construction within the notch 66 it can be appreciated that if projections extended within the notch such projections may be problematic or less than desirable.
It is to be appreciated that one of many possible uses of such an engagement between the rail pad assembly 10 and the rail tie 8 is for ease of transportation of the tie/rail pad (pre-assembly) as one unit. Another possible use is to hold the rail pad assembly 10 in place relative to the rail tie 8. As yet another example of a use is to keep the rail pad assembly 10 from coming off of the rail tie 8.
Another embodiment of a rail pad assembly 10′ is shown in
Still other features and functions of the present invention include increased efficiencies concerning labor and cost. As one example, in distinction from the use of adhesive tape, the present invention is believed to provide a cost savings of approximately US $0.08 per unit.
It is to be appreciated that the present examples presented and discussed herein are merely examples and that the present invention certainly encompasses examples not presented herein. Moreover, the function as provided by a means is to be considered within the scope of the present invention. It is to be appreciated that the present invention is applicable to a pad assembly that has any number of components and/or a single component pad.
Benefit of priority is claimed from U.S. Provisional Patent Application Ser. No. 60/780,390 filed on Mar. 7, 2006, the complete disclosure of which is hereby expressly incorporated herein by this reference thereto.
Number | Date | Country | |
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60780390 | Mar 2006 | US |