| WO/2001/029319 | MAT CONSISTING OF TUBES |
| JP2003042207 | SHOCK ABSORBER UNIT |
| WO/1995/030796 | RAIL ARRANGEMENT |
WANG, Donghua (R502 No. 16 Lane 1068 Jingao Rd, Shanghai 8, 206208, CN)
LI, Guangze (R303 No. 10 Lane 155 Baocheng Rd, Shanghai 0, 201100, CN)
WANG, Donghua (R502 No. 16 Lane 1068 Jingao Rd, Shanghai 8, 206208, CN)
| CLAIMS: 1. A rail fastener for mounting a rail to a support foundation, the rail extends along a first direction, said rail fastener including: - a bottom plate for engaging the support foundation; - a top plate with rail-mounting member for engaging the rail; - a first elastomeric body between the top plate and the bottom plate for supporting the top plate on the bottom plate; characterized in that the rail fastener further includes: - at least one pressing member for pressing the top plate towards the bottom plate or pressing the bottom plate towards the top plate. 2. The rail fastener of claim 1, characterized in that said pressing member presses the top plate towards the bottom plate or presses the bottom plate towards the top plate through a second elastomeric body, said second elastomeric body is between the top plate and the pressing member, or the bottom plate and the pressing member. 3. The rail fastener of claim 1 or 2, characterized in that said pressing member presses the top plate towards the bottom plate. 4. The rail fastener of any one of claims 1 to 3, characterized in that said top plate has two opposing top plate ends disposed along a second direction perpendicular to the first direction, and said pressing member presses the top plate towards the bottom plate at the respective two opposing top plate ends. The rail fastener of claim 4, characterized in that the two opposing top plate ends are offset with respect to a line parallel to the second direction. The rail fastener of claim 5, characterized in that said bottom plate has two opposing bottom plate ends disposed along the second direction, said two opposing bottom plate ends are offset with respect to the line parallel to the second direction. The rail fastener of claim 6, wherein the bottom plate is shaped to receive the top plate. The rail fastener of claim 7, characterized in that the two opposing top plate ends are disposed on a line parallel to the second direction. The rail fastener of claim 6 or 7, characterized in that the pressing member engages the respective two opposing bottom plate ends. The rail fastener of any one of claims 1 to 5 and 8, characterized in that the bottom plate has two opposing bottom plate ends disposed along the second direction, and the pressing member engages the respective two opposing bottom plate ends. The rail fastener of claim 9 or 10, characterized in that the pressing member and the opposing bottom plate ends are secured by a bolt. 12. The rail fastener of any of claims 4 to 11, characterized in that each of the two opposing top plate end is rectangular-shaped having a length along the first direction, and the second elastomeric body covers the entire said length. The rail fastener of any of claims 4 to 11, characterized in that each of the two opposing top plate end is rectangular-shaped having a width along the second direction, and the second elastomeric body covers a portion of said width. The rail fastener of any of claims 4 to 11, characterized in that each of the two opposing top plate end is circular-shaped having a circumference, and the second elastomeric body covers the entire said circumference. 15. The rail fastener of any of claims 1 to 14, characterized in that the top plate has a top plate bottom surface facing the bottom plate, and the entire said top plate bottom surface is provided with the first elastomeric body. The rail fastener of any of claims 1 to 14, characterized in that the top plate has a top plate bottom surface facing the bottom plate, and a portion of said top plate bottom surface is provided with the first elastomeric body. The rail fastener of any of claims 1 to 14, characterized in that the top plate has a top plate bottom surface facing the bottom plate, and the entire said top plate bottom surface is not provided with the first elastomeric body. 8. A rail fastener for mounting a rail to a support foundation, the rail extends along a first direction, said rail fastener including: - a bottom plate for engaging the support foundation; - a top plate with rail-mounting member for engaging the rail, said top plate having two opposing top plate ends disposed along a second direction perpendicular to the first direction, and the two opposing top plate ends are offset with respect to a line parallel to the second direction; - a first elastomeric body between the top plate and the bottom plate for supporting the top plate on the bottom plate; characterized in that said bottom plate has two opposing bottom plate ends disposed along the second direction, said two opposing bottom plate ends are offset with respect to the line parallel to the second direction. A rail system having a rail fastener of any one of claims 1 to 18. A method of mounting a rail to a support foundation, the rail extends along a first direction, said method including the steps of: providing a rail fastener including: - a bottom plate for engaging the support foundation; - a top plate with rail-mounting member for engaging the rail; - a first elastomeric body between the top plate and the bottom plate for supporting the top plate on the bottom plate; - at least one pressing member for pressing the top plate towards the bottom plate or pressing the top plate towards the bottom plate; engaging the rail to the top plate. A method of making a rail fastener for mounting a rail to a support foundation, the rail extends along a first direction, said method including the steps of providing a bottom plate for engaging the support foundation; providing a first elastomeric body on the bottom plate; mounting a top plate to the bottom plate, such that the first elastomeric body is between the top plate and the bottom plate for supporting the top plate on the bottom plate; pressing the top plate towards the bottom plate or the bottom plate towards the top plate by at least one pressing member. |
Field of the Invention
This invention relates to rail fasteners for suspending a rail over a support foundation, more particularly those having a resilient elastomeric layer between a top plate and a bottom plate.
Objects of the Invention
Therefore, it is an object of this invention to resolve at least one or more of the problems as set forth in the prior art. Particularly, it is an object of the current invention to provide rail fasteners having a resilient elastomeric layer between a top plate and a bottom plate with multiple effective spring rates. As a minimum, it is an object of this invention to provide the public with a useful choice. Summary of the Invention
Accordingly, this invention provides a rail fastener for mounting a rail to a support foundation. The rail extends along a first direction. The rail fastener includes a bottom plate for engaging the support foundation, and a top plate with rail-mounting member for engaging the rail. A first elastomeric body between the top plate and the bottom plate for supporting the top plate on the bottom plate. The rail fastener further includes at least one pressing members for pressing the top plate towards the bottom plate or pressing the bottom plate towards the top plate.
Preferably, the pressing member presses the top plate towards the bottom plate or presses the bottom plate towards the top plate through a second elastomeric body. The second elastomeric body is between the top plate and the pressing member, or the bottom plate and the pressing member.
Optionally, the pressing member presses the top plate towards the bottom plate.
Advantageously, the top plate has two opposing top plate ends disposed along a second direction perpendicular to the first direction, and the pressing member presses the top plate towards the bottom plate at the respective two opposing top plate ends. Preferably, the two opposing top plate ends are offset with respect to a line parallel to the second direction. More preferably, the bottom plate has two opposing bottom plate ends disposed along the second direction, said two opposing bottom plate ends are offset with respect to the line parallel to the second direction. Even more preferably, the bottom plate is shaped to receive the top plate.
Alternatively, the two opposing top plate ends are disposed on a line parallel to the second direction.
Advantageously, the pressing member engages the respective two opposing bottom plate ends. More preferably, the pressing member and the respective opposing bottom plate ends are secured by a bolt.
Preferably, each of the two opposing top plate end is rectangular-shaped having a length along the first direction, and the second elastomeric body covers the entire said length. Optionally, each of the two opposing top plate end is rectangular-shaped having a width along the second direction, and the second elastomeric body covers a portion of said width.
Preferably, each of the two opposing top plate end is circular-shaped having a circumference, and the second elastomeric body covers the entire said circumference.
Preferably, the top plate has a top plate bottom surface facing the bottom plate, and the entire said top plate bottom surface is provided with the first elastomeric body. Alternatively, a portion of said top plate bottom surface is provided with the first elastomeric body, or the entire said top plate bottom surface is not provided with the first elastomeric body.
It is another aspect of this invention to provide a rail fastener for mounting a rail to a support foundation, the rail extends along a first direction, said rail fastener including:
- a bottom plate for engaging the support foundation;
a top plate with rail-mounting member for engaging the rail, said top plate having two opposing top plate ends disposed along a second direction perpendicular to the first direction, and the two opposing top plate ends are offset with respect to a line parallel to the second direction;
a first elastomeric body between the top plate and the bottom plate for supporting the top plate on the bottom plate;
characterized in that said bottom plate has two opposing bottom plate ends disposed along the second direction, said two opposing bottom plate ends are offset with respect to the line parallel to the second direction. It is yet another aspect of this invention to provide a rail system having the above rail fasteners.
It is a further aspect of this invention to provide a method of mounting a rail to a support foundation. The rail extends along a first direction. A rail fastener is provided, which includes:
- a bottom plate for engaging the support foundation;
- a top plate with rail-mounting member for engaging the rail;
- a first elastomeric body between the top plate and the bottom plate for supporting the top plate on the bottom plate;
- at least one pressing member for pressing the top plate towards the bottom plate or pressing the bottom plate towards the top plate.
The rail is engage to the top plate. It is another aspect of this invention to provide a method of making a rail fastener for mounting a rail to a support foundation. The rail extends along a first direction. A bottom plate is provided for engaging the support foundation, and a first elastomeric body is provided on the bottom plate. A top plate is then mounted to the bottom plate , such that the first elastomeric body is between the top plate and the bottom plate for supporting the top plate on the bottom plate. The top plate has rail-mounting member for engaging the rail. At least one pressing member is then provided to press the top plate towards the bottom plate or press the bottom plate towards the top plate.
Brief description of the drawings Preferred embodiments of the present invention will now be explained by way of example and with reference to the accompanying drawings in which:
Figure 1 shows various views of a first exemplary rail fastener;
Figure 2 shows a perspective view of the rail fastener of Figure 1 without the rail;
Figure 3 shows another exemplary rail fastener with a different top plate design;
Figure 4 shows the installation of the pressing member onto the rail fastener of Figure i;
Figure 5 shows an alternative design of the pressing member and the bottom plate for the rail fastener;
Figure 6 shows the a view of the elastomeric body between the top plate and the bottom plate of the rail fastener;
Figure 7 shows the vertical stiffness of the rail fastener of the current invention with effective segmented multiple spring rates by finite element analysis on modeled/predicted performance data;
Figure 8 shows an alternative design of the top plate and bottom plate for the rail fastener;
Figure 9 shows another exemplary rail fastener;
Figure 10 shows yet another exemplary rail fastener;
Figure 11 shows an alternative rail fastener having pressing member that presses the bottom plate towards the top plate.
Detailed Description of the Preferred Embodiments
This invention is now described by way of example with reference to the figures in the following paragraphs. List 1 below is a part list so that the reference numerals in the figures may be easily referred to. Reference Numerals Description
10 Rail fastener
12 Rail
20 Top plate
22 Rail engaging member
24 Top plate end
30 Bottom plate
32 Support foundation engaging member
34 Bottom plate end
40 First elastomeric body
42 First elastomeric body end
44 First elastomeric body side
50 Pressing member
60 Second elastomeric body
70 Pressing member maintaining member
List 1
Objects, features, and aspects of the present invention are disclosed in or are apparent from the following description. It is to be understood by one of ordinary skilled in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
An exemplary rail fastener 10 is shown in Figures 1 to 3. The rail fastener 10 has a top plate 20 with rail engaging member 22 to which the rail 12 is engaged. The rail engaging member 22 can be various known devices, including but not limited to track clamp, mound, and Pandrol clips. The top plate 20 in Figure 1 is formed by a solid piece of material, while the top plate 20 in Figure 3 has a hollow core. The rail fastener 10 has a bottom plate 30 for engaging the support foundation, which may be the ground, through various know mechanisms including but not limited to lugs and screws. The top plate 20 and bottom plate 30 can be formed by any suitable materials including cast iron or steel, spheroidal graphite iron. Between the top plate 20 and the bottom plate 30 is a first elastomeric body 40, which may be cured to the top plate 20 and the bottom plate 30, or may be shaped appropriately as a boot as described in WO 2005/108675A1, which is hereby incorporated by reference regarding such shaping, such that the top plate 20, the bottom plate 30, and the first elastomeric body 40 are held together without the use of vulcanization or traditional holding fixtures. The first elastomeric body 40 can be made of any suitable natural or synthetic elastomers. The first elastomeric body 40 may embrace the entire side of the top plate 20 by the first elastomeric body side 44 as shown in Figure 6, or the first elastomeric body side 44 in Figure 6 may be omitted if desired. Preferably the elastomer body is cure bonded with the plates, preferably with the plates and elastomer vulcanized cured mold bonded in a mold. Preferably with the elastomer and metal plates bonded with an elastomer to metal adhesive.
At least one pressing member 50 is provided to press the top plate towards the bottom plate as shown in Figures 1 to 5. Alternatively, the pressing member 50 can press the bottom plate 30 towards the top plate instead, as shown in Figure 11. It was surprisingly found that because of the pressing by the pressing member 50, the rail fastener of the current invention has effective segmented multiple spring rates, as shown in Figure 7. Thus the rail fastener of the current invention can provide additional damping to minimize undesirable vibrations of different frequencies, and is suitable for use in various working conditions, for example, deflection control, normal operation, and extreme conditions.
As shown in the section A-A in Figure 1 and section H-H in Figure 3, the top plate 20 has two opposing top plate ends 24 disposed along a second direction. This second direction is substantially perpendicular to the first direction along which the rail 12 extends. At these two opposing top plate ends 24, respective pressing members 50 are provided for pressing the top plate 20 towards the bottom plate 30 through a second elastomeric body 60 between the top plate and the respective pressing members. This second elastomeric body 60 may be unified with the first elastomeric body 40 as shown in Figures 3 to 5, or can be separated from the first elastomeric body 40 as shown in Figures 1, 9, and 10. In the later case, the second elastomeric body 60 may be made of a material different from that of the first elastomeric body 40 to achieve different effective spring rates if desired. The second elastomeric body is optional but is preferred for better electric isolation. Figure 4 shows the detailed installation of the pressing member 50 onto one top plate end 24. In step 1, before the application of the pressing member 50, the top plate 20 together with the first elastomeric body 40 and the second elastomeric body 60 may have a height g, which is, for example, higher than the height a of the base plate 30 as shown in Figure 4. In step 2, the pressing member 50 is provided on the second elastomeric body 60, which is then pressed such that the height of the top plate 20 together with the first elastomeric body 40 and the second elastomeric body 60 equals to that of the bottom plate. However, it should be noted that the rail fastener 10 of the current invention will still work as long as the top plate 20 is pressed towards the bottom plate 30 through the second elastomeric body 60, that is, the height of the top plate 20 together with the first elastomeric body 40 and the second elastomeric body 60 should be any value smaller than g after the top plate 20 is pressed by the pressing member 50.
An alternative pressing member 50 is shown in Figure 5, which is in the form of a U-shaped clip engaging the bottom plate. Different from the example in Figure 4, before the application of the pressing member 50, the top plate 20 together with the first elastomeric body 40 and the second elastomeric body 60 may have a height g, which is lower than the height a of the base plate 30. However, the pressing member 50 in Figure 5 is still able to press the top plate 20 towards the bottom plate 30 by compensating the difference in the heights.
The pressing members 50 are preferably maintained at the pressing position by a pressing member maintaining member 70, for example a bolt that can be conveniently installed to the rail fastener 10. However, this pressing member maintaining member 70 may not be necessary if the pressing member 50 can itself maintain its position with respect to the rail fastener. For example, a bolt having an enlarged bolt head may achieve the dual function of pressing the top plate and maintaining its own position in the rail fastener. Alternatively, the U-shaped clip as shown in Figure 5 can also achieve this purpose.
In Figures 1 to 3, each of the two top plate ends 24 is in a general rectangular shape, and the second elastomeric body 60 covers the entire length along the direction of the rail of this rectangular-shaped top plate ends 24. However, it is also possible that the second elastomeric body 60 covers only a portion of this length. Figure 9 shows an alternative embodiment in which only a portion of the width along the direction traversing the rail of the top plate ends is covered by the second elastomeric body 60. Figure 10 shows yet another embodiment of the current invention in which the top plate ends 24 is circular-shaped and has a circumference, and the second elastomeric body 60 covers the entire circumference.
As shown in Figures 1 to 3, the pressing member 50 is not required to cover the entire elastomeric body 60, while in some specific embodiments like those in Figures 9 and 10 this may be preferred. It should be noted that it is possible to have only one pressing member 50 to press the top plate 20 towards the bottom plate 30, or press the bottom plate 30 towards the top plate 20. It is possible to have the pressing member 50 pressing, for example, the middle of the top plate 20 or bottom plate 30, if desired. It is not necessary for the pressing member 50 to press the top plate 20 or bottom plate 30 at the top plate ends 24 or bottom plate ends 34. Further, it is possible to have the pressing member 50 pressing only one of the top plate ends 24 or one of the bottom plate ends 34, or at any other suitable position if desired. The pressing member 50 can press the top plate 20 or bottom plate 30 directly (that is, the pressing member 50 directly engages with the top plate 20 or bottom plate 30), or indirectly (through the second elastomeric body 60 or any other suitable components, for example the rail engaging member 22).
In the embodiments in Figures 1 to 3, the bottom plate 30 has a recess with inclined side flanks, which are complementary to the top plate ends 24. This is an optional feature, and the flanks can be vertical as shown in Figure 4, which are preferred alternative embodiments.
In the embodiments in Figures 1 to 3 and 9 to 10, the two opposing top plate ends 24 of the top plate 20 are offset with respect to a line parallel to direction traversing that of the rail. Due to bigger projection area in the direction traversing the rail, the rail fastener having offset top plate ends is more resistant to lateral deflection, which helps to maintain the track gage. Similarly, the base plate could also have two opposing bottom plate ends 34 that are offset with respect to a line parallel to direction traversing that of the rail. One advantage of this arrangement is that the rail fastener could engage the ground with less number of lugs, for example two as shown in Figures 1 to 3, which reduces the overall size of the rail fastener. It is preferred that the base plate 30 is shaped to receive the top plate 20 in which both of them have respective offset ends. However, it is possible to have a top plate with offset ends and a bottom plate without offset ends sacrificing the size advantage. Figure 8 shows a so-called "in-line" design of the current invention, in which the two opposing ends 24 and 34 of the top plate 20 and the bottom plate 30, respectively, lies on a line traversing the rail.
The entire bottom of the top plate 20 can be provided with the first elastomeric body. Alternatively, only a portion of the top plate 20 can be provided with the first elastomeric body. If desired, the entire bottom of the top plate 20 is not provided with the first elastomeric body.
With the provision of the pressing member 50 to press the top plate 20 towards the bottom plate 30 or press the bottom plate 30 towards the top plate 20, it is possible to provide a rail fastener with a relatively low spring rate with improved vibration attenuation. The overall spring rate of the rail fastener can be below 15 kN/mm, more preferably 3 to 15 kN/mm, and more preferably 3 to 10 kN/mm, yet maintaining reasonable deflection range. Further, with the current invention, it is possible to provide a rail fastener of a relatively small overall size having multiple effective spring rates without the use of additional biasing members like additional springs. As such, the overall structure of the rail fasteners is relatively simple. Other than providing additional damping, reduction in size of the rail fastener is desirable. This is because the installation of such fasteners is sometimes restricted due to lack of available spaces. The size of rail fastener of the current invention may further be reduced by the offset ends of the top plate 20 and bottom plate 30 along the direction traversing the rail.
While the preferred embodiment of the present invention has been described in detail by the examples, it is apparent that modifications and adaptations of the present invention will occur to those skilled in the art. Furthermore, the embodiments of the present invention shall not be interpreted to be restricted by the examples or figures only. It is to be expressly understood, however, that such modifications and adaptations are within the scope of the present invention, as set forth in the following claims. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the claims and their equivalents.