The present invention is a system and a method for securing tuned mass dampers to rail.
Various devices for securing rail seals to a rail are known. The rail seals typically are used at level crossings, where the rail seals and the clips used to hold the rail seals in place are typically buried under asphalt or concrete at the level crossing, after installation. A clip assembly for a rail seal is illustrated and described in U.S. Pat. No. 6,213,407. Because the clip assembly and the rail seal held thereby are intended to be covered by asphalt or concrete, the extent to which the clip assembly extends outwardly from the rail is generally not important.
In contrast, tuned mass dampers may be attached or secured to linear rails, along the lengths of rail outside the level crossings. The tuned mass dampers primarily are designed to minimize the extent to which vibrations resulting from traffic over the rails may be transmitted as airborne noise. As is known in the art, the tuned mass dampers are formed to have a mass and an overall density designed to dampen vibrations of the rail generated by the movement of rail car wheels along the rail.
It is important that the installed tuned mass dampers, and the devices holding them to the rail, extend outwardly from the rail only a relatively short distance. This is in contrast to the less onerous requirements for conventional clip assemblies securing rail seals at level crossings, described above. Along the exposed parts of the rail that are located outside the level crossings, the devices that secure the tuned mass dampers to rails are required to fit within a relatively small envelope or perimeter relative to the rail. This is due to the routine rail and track bed maintenance tasks (e.g., ballast tamping, and rail grinding) that are required to be done to the rail and ballast located outside the level crossings. In order for these routine maintenance tasks to be completed efficiently, the tuned mass dampers and the clips holding them may extend outwardly from the track only a relatively short distance.
The prior art devices that have been used to secure tuned mass dampers to a rail outside the level crossings are generally unsatisfactory because they are relatively expensive, and/or difficult to use, and/or ineffective.
There is a need for a system and a method for securing tuned mass dampers to a rail that overcome or mitigate one or more of the disadvantages or defects of the prior art. Such disadvantages or defects are not necessarily included in those described above.
In its broad aspect, the invention provides a clip assembly for securing first and second tuned mass dampers to respective first and second sides of a rail. The clip assembly includes a bar element having a connector portion extending between first and second ends thereof and formed to be positioned in a predetermined location relative to the rail at least partially under a foot of the rail, a first clamping arm connected with the connector portion at the first end of the connector portion, the first clamping arm being formed to engage the first tuned mass damper to urge the first tuned mass damper against the first side of the rail and at least partially downwardly toward the foot, when the connector portion is in the predetermined location, and a linkage section connected with the connector portion at the second end of the connector portion, the linkage section comprising a curved wall with an opening therein. The clip assembly also includes a second clamping arm extending between upper and lower ends thereof. The lower end includes a locking portion at least partially receivable in the opening in the curved wall. The locking portion is securable to the linkage section, and the upper end is formed for engagement with the second tuned mass damper, to urge the second tuned mass damper against the second side of the rail and at least partially downwardly toward the foot.
In another aspect, the invention provides a system including a clip assembly for securing first and second tuned mass dampers on respective first and second sides of a rail. The clip assembly includes a bar element having a connector portion extending between first and second ends thereof and formed to be positioned in a predetermined location relative to the rail at least partially under a foot of the rail, a first clamping arm connected with the connector portion at the first end of the connector portion, the first clamping arm being formed to engage the first tuned mass damper to urge the first tuned mass damper against the first side of the rail and at least partially downwardly toward the foot, when the connector portion is in the predetermined location, and a linkage section connected with the connector portion at the second end of the connector portion, the linkage section comprising a curved wall with an opening therein. The clip assembly also includes a second clamping arm extending between upper and lower ends thereof. The lower end includes a locking portion at least partially receivable in the opening in the curved wall. The locking portion is securable to the linkage section. The upper end is formed for engagement with the second tuned mass damper, to urge the second tuned mass damper against the second side of the rail and at least partially downwardly toward the foot. The system also includes an installation tool configured for engagement with the curved wall and the second clamping arm, for urging the first and second clamping arms against the first and second tuned mass dampers respectively, and to secure the locking portion to the linkage section.
In another of its aspects, the invention provides a method of installing a clip assembly for securing first and second tuned mass dampers on respective first and second sides of a rail. The method includes inserting a linkage section of a bar element of the clip assembly underneath a first side of a foot of the rail. The linkage section is pushed in a first direction underneath the foot of the rail, to position a connector portion of the bar element in a predetermined location relative to the first and second tuned mass dampers, and to engage a first clamping arm that is connected with the connector portion with the first tuned mass damper. A locking portion body of a locking portion at the lower end of a second clamping arm of the clip assembly is inserted into an opening in a curved wall of the linkage section, to engage a locking element positioned on a lower surface of the locking portion body with a lower edge element of the curved wall that partially defines the opening, to hold the locking portion of the second clamping arm in the linkage section. An installation tool is positioned to engage one or more first contact portions thereof with the bracing element, and to engage one or more second contact portions thereof with the bearing surface of the second clamping arm. With the first contact portion, the bracing element is pulled at least partially in the first direction, to urge the first clamping arm in the first direction against the first tuned damper element, and simultaneously with the second contact portion, urging the second clamping arm in the second direction against the second tuned damper element.
In yet another of its aspects, the invention also provides a pair of tuned mass dampers for damping airborne vibrations from a rail generated by movement of wheels over the rail, the rail including a web portion supported by a foot thereof. Each of the tuned mass dampers includes a body including an elastomeric material and one or more insert elements embedded in the elastomeric material. The body also includes an inner side formed for engagement with the web portion and an outer side of the body opposite to the inner side thereof, the outer side having an upper part and a lower part formed to be located below the upper part when the inner side of the tuned mass damper is engaged with the web portion. The upper and lower parts are at least partially separated by a slot with a recessed region therein defined by upper and lower surfaces positioned at least partially inwardly from the outer side.
The invention also provides a system for damping airborne vibrations from a rail generated by wheels rolling over the rail, the rail including a web portion supported by a foot. The system includes first and second tuned mass dampers, the first and second tuned mass dampers being engaged with opposite first and second sides of the web portion and being at least partially supported by the foot of the rail. The system also includes a clip assembly for securing the first and second tuned mass dampers to the respective first and second sides of a rail. The clip assembly includes a bar element having a connector portion extending between first and second ends thereof and formed to be positioned in a predetermined location relative to the rail at least partially under the foot of the rail, a first clamping arm connected with the connector portion at the first end of the connector portion, the first clamping arm being formed to engage a lower surface of the first tuned mass damper to urge the first tuned mass damper against the first side of the rail and at least partially downwardly toward the foot, when the connector portion is in the predetermined location. The bar element also includes a linkage section connected with the connector portion at the second end of the connector portion, the linkage section including a curved wall with an opening therein. The clip assembly also includes a second clamping arm extending between upper and lower ends thereof. The lower end includes a locking portion at least partially receivable in the opening in the curved wall. The locking portion is securable to the linkage section, and the upper end is formed for engagement with the lower surface of the second tuned mass damper, to urge the second tuned mass damper against the second side of the rail and at least partially downwardly toward the foot.
The invention will be better understood with reference to the attached drawings, in which:
In the attached drawings, like reference numerals designate corresponding elements throughout. Reference is first made to
The bar element 32 preferably also includes a linkage section 44 connected with the connector portion 34 at the second end 38 of the connector portion 34. As can be seen in
In one embodiment, the clip assembly 20 preferably also includes a second clamping arm 50 extending between upper and lower ends 52, 54 thereof (
As will be described, the first and second sides 26, 28 are sides of a web portion “W” of the rail 30.
As can be seen in
As can be seen in
It can also be seen in
The first engagement portion 64 preferably is located relative to the connector portion 34 so that, when the first clamping arm 42 is urged in a first direction (generally indicated by arrow “A” in
When the first engagement portion 64 engages the lower surface 68 and is urged against the lower surface 68, the force exerted by the first engagement portion 64 (schematically represented by arrow “A1” in
As illustrated in
As can be seen in
The Applicant has determined that the tuned mass dampers 22, 24 are more effective at damping airborne vibration (i.e., noise) when they are at least partially urged downwardly, against the foot 40 of the rail 30. That is, a tuned mass damper that is solely urged in a substantially horizontal direction by engagement of the first engagement portion 64 with the lower surface 68 has been found to dampen noise less effectively than if the tuned mass damper were urged both horizontally and downwardly (i.e., as illustrated for exemplary purposes in
It is also preferred that the second clamping arm 50 includes a second engagement portion 70 at the upper end 52 thereof, for engaging the second tuned mass damper 24. As can be seen in
It can also be seen in
The second engagement portion 70 preferably is located relative to the locking portion 56 so that, when the second clamping arm 50 is urged in a second direction (generally indicated by arrow “B” in
When the second engagement portion 70 engages the lower surface 74 and is urged against the lower surface 74, the force exerted by the second engagement portion 70 (schematically represented by arrow “B1” in
As illustrated in
Those skilled in the art would appreciate that the forces schematically represented by the arrows “A1” and “B1” in
As can be seen in
As noted above, the Applicant has determined that the tuned mass dampers 22, 24 are more effective at damping airborne vibration (i.e., noise) when they are at least partially urged downwardly, against the foot 40 of the rail 30.
As can be seen in
The first tuned mass damper 22 is also illustrated in
As can be seen in
Those skilled in the art would appreciate that the tuned mass dampers may be made of any suitable material, or combination of materials, to provide a tuned mass damper with suitable density and stiffness. The tuned mass dampers ideally have densities and other physical characteristics so that the tuned mass dampers, once secured to the rail, minimize airborne noise. For instance, in one embodiment, the tuned mass dampers may include pieces of steel embedded in an elastomeric matrix.
As can be seen in
As noted above, it is important that the extent to which the clip assembly 20, once installed, extends laterally outwardly from the outer sides “OS1” and “OS2” be minimized. Preferably, the sizes of the tuned mass dampers are minimized. Because of the recessed regions 66, 72, the clip assembly 20 once the clip assembly 20 is installed, the extent to which the first and second clamping arms 44, 50 extend laterally outwardly from the outer sides “OS1” and “OS2” is minimized.
As will be described, it is preferred that the clip assembly 20 initially is manually positioned on the first and second tuned mass dampers 22, 24, and also on the rail 30. It will be understood that, when the clip assembly 20 has been manually positioned on the first and second tuned mass dampers 22, 24, the first and second engagement portions 64, 70 may only lightly engage the respective lower surfaces 68, 74. Once the clip assembly 20 is positioned so that the first and second engagement portions 64, 70 engage the lower surfaces 68, 74, the second clamping arm 50 is urged in the direction indicated by arrow “B”, and the first clamping arm 42 is urged in the direction indicated by arrow “A”, to install the clip assembly 20 against the first and second tuned mass dampers 22, 24.
As a practical matter, it is convenient for a user (not shown) to manually position the bar element 32 so that the linkage section 44 is positioned underneath the foot 40, proximal to the second tuned mass damper 24, and the first engagement portion 64 is at least proximal to the lower surface 68 of the first tuned mass damper 22 (
Those skilled in the art would appreciate that the rail 30 may be supported by sleepers or railway ties (not shown) that are spaced apart from each other along the rail 30. Ballast 75 is located between the railway ties (
Those skilled in the art would appreciate that, in order to install the clip assembly 20, the linkage section 44 of the bar element 32 is first inserted into the ballast 75, underneath a left (or first) side 76 of the foot 40 (
Those skilled in the art would also appreciate that the amount of the ballast 75 at respective locations along the track relative to the rail may vary. It is preferred that the clip assembly 20 is installed at a location along the track where there is somewhat less ballast 75 present, to permit easier installation of the clip assembly 20.
The bar element 32 preferably is manually pushed in the direction indicated by arrow “C” until the first engagement portion 64 engages the lower surface 68 of the first tuned mass damper 22. As noted above, the first engagement portion 64 may only lightly engage the lower surface 68, because the installation at this point is done manually. When the bar element 32 is at the point where the first engagement portion 64 lightly engages the lower surface 68, the connector portion 34 of the bar element 32 is in its predetermined location. It is preferred that, when the connector portion 34 is in the predetermined location therefor, the connector portion 34 is horizontal, or substantially horizontal, as illustrated in
As can be seen in
Once the second clamping arm 50 is positioned with the locking portion 56 in the opening 48 and the second engagement portion 70 engaging the lower surface 74, the clip assembly 20 preferably is secured to the first and second tuned mass dampers 22, 24 by an installation tool 80. As can be seen in
As can be seen in
As can be seen in
As illustrated in
In one embodiment, the curved wall 46 of the linkage section 44 preferably includes a lower edge element 98 that a least partially defines the opening 46 (
Preferably, the locking elements 102 include a number of teeth 104 (
It will be understood that the teeth 104 preferably define notches 106 therebetween respectively (
Preferably, after the clip assembly 20 has been manually installed as described above (i.e., with the first and second engagement portions 64, 70 lightly engaging the respective lower surfaces 68, 74, and the locking portion 56 received in the opening 48 of the curved wall 46), the first contact portion 82 of the installation tool 80 is pushed into the ballast 75, in the direction generally indicated by arrow “E” in
Once the first contact portion 82 engages the bracing element 58, an upper end 108 of the installation tool 80 preferably is moved in the direction indicated by arrow “G” in
At the same time as the second contact portion 84 urges the second clamping arm 50 in the direction indicated by arrow “B”, the first contact portion 82 pulls the bracing element 58 generally in the direction indicated by arrow “F”. Because the connector portion 34 is connected with the bracing element 58 via the curved wall 46, the connector portion 34 is pulled as a result in the direction indicated by arrow “C” in
It will also be understood that, when the first contact portion 82 urges the bracing element 58 in the direction indicated by arrow “F”, the lower edge element 98 may be moved outwardly, i.e., in the direction indicated by arrow “C”. In this way, when the installation tool 80 is applied to urge the first and second clamping arms 42, 50 generally toward each other as described above, the lower edge element 98 simultaneously is positioned in a selected notch 106 which can hold the first and second clamping arms 42, 50 in position, i.e., held then urged against the first and second tuned mass dampers 22, 24 respectively. Because of the positioning of the lower edge element 98 in the selected notch 106 when the installation tool 80 is applied, the bar element 32 and the second clamping arm 50 are held locked together thereby, when the installation tool 80 is removed.
Those skilled in the art would appreciate that the bar element and the second clamping arm may be made of any suitable material, or materials. For example, in one embodiment, the bar element 32 preferably is made of spring steel. This enables the connector portion 34 to deform upwardly toward the foot 40 of the rail 30, when the first and second engagement portions 64, 70 are urged against the first and second tuned mass dampers 22, 24 respectively. The upward deformation of the connector portion 34 is in the direction indicated by arrow “H” in
Also, those skilled in the art would appreciate that the second clamping arm 50 may be made of mild steel, or spring steel.
In one embodiment, the invention preferably includes a system 110 that includes the clip assembly 20 and the installation tool 80. In use, as outlined above, the linkage section 44 of the bar element 32 is inserted underneath the left (or first) side 76 of the foot 40 and pushed through the ballast 75 underneath the foot 40 until the connector portion 34 of the bar element 32 is in the predetermined location thereof, relative to the first and second tuned mass dampers 22, 24. At this point, the linkage section 44 preferably is generally proximal to the side 78 of the foot 40 that is below the second tuned mass damper 24, i.e., the linkage section is also in its predetermined location. When the connector portion 34 is in its predetermined location, the first clamping arm 42 is engaged with the first tuned mass damper 22.
Once the connector portion 34 and the linkage section 44 are in their predetermined locations, the locking portion body 90 of the locking portion 56 of the second clamping arm 50 is inserted into the opening 48 of the curved wall 46 of the linkage section 44, so that a selected one of a number of locking elements 102 on a lower surface of the locking portion body 90 is engageable with a lower edge element 98 of the curved wall 46 that partially defines the opening 48. The installation tool 80 is used to secure the second clamping arm 50 to the linkage section 44, as described above. Once the second clamping arm 50 is secured to the linkage section 44, the locking portion 56 of the second clamping arm 50 is held in the linkage section 44 by the lower edge element 98 engaging the selected one of the locking elements 102.
The installation tool 80 is positioned to engage the first contact portion 82 of the installation tool 80 with the bracing element 58 of the curved wall 46, and also to engage the second contact portion 84 thereof with the bearing surface 88 of the second clamping arm 50. With the first contact portion 82 of the installation tool 80, the bracing element 58 is pulled at least partially in the first direction, to urge the first clamping arm 42 against the first tuned mass damper 22. With the second contact portion 84 of the installation tool 80, pressure is exerted on the bearing surface 88 in the second direction, to urge the second clamping arm in the second direction against the second tuned mass damper 24.
As noted above, the tuned mass dampers 22, 24 preferably include a suitable elastomeric material. Due to the resilience of the spring steel of the bar element 32 and the resilience of the elastomeric material in the tuned mass dampers, the bar element 32 preferably is subjected to tension as the installation of the clip assembly 20 is completed, so that once the locking elements 102 are engaged with the lower edge element 98 of the curved wall 46, they tend to stay so engaged.
It will be appreciated by those skilled in the art that the invention can take many forms, and that such forms are within the scope of the invention as claimed. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.