TAMPING TOOL

Information

  • Patent Application
  • 20170298576
  • Publication Number
    20170298576
  • Date Filed
    April 11, 2017
    7 years ago
  • Date Published
    October 19, 2017
    7 years ago
Abstract
The present disclosure generally relates to an improved railroad track ballast tamping tool. The tamping tool may be lowered into ballast underlying railroad tracks and between railroad track ties for performing ballast tamping operations. The tamping tool includes a shank and a paddle coupled to the shank. The paddle comprises a top ridge disposed on a top surface of the paddle and a bottom ridge disposed on a bottom surface of the paddle. The tamping tool additionally includes a top surface wear tile coupled to the top surface of the paddle and abutting a rear face of the top ridge, a bottom surface wear tile coupled to the bottom surface of the paddle and abutting a rear face of the bottom ridge, and a nose wear tile coupled to the top and bottom surfaces of the paddle and abutting a front face of both the top and bottom ridges.
Description
BACKGROUND

Railroads are generally constructed of a pair of elongated, substantially parallel rails, which are coupled to a plurality of laterally extending ties via metal tie plates and spikes and/or spring clip fasteners. The rails and ties are disposed on a bed formed of hard particulate material, such as gravel. This hard particulate material, which is called ballast, often underlies or surrounds the rails and ties.


During operation of the railroad, underlying ballast tends to shift or move from its position relative to the rails and ties. As such, a level of support provided by the ballast may be unwantedly reduced. To maintain the ballast, the ballast adjacent to and/or under the ties may be “tamped,” or compressed, to ensure that the ties and rails do not shift. This tamping process ensures that the rails and ties are sufficiently aligned, stable, and durable.


A rail vehicle for carrying out tamping operations is generally referred to as a “tamper” or a “tamping machine” and includes work heads for carrying out tamping operations. Such work heads typically include replaceable tamping tools to help compress the ballast. The replaceable tamping tools pound into the ballast as the tamping machine moves along the track. Known tamping tools tend to wear out from the pounding impact with the ballast and will often require replacement or repair as a result of repeated impact.


To extend the life of typical tamping tools, tamping tools often include wear-resistant materials such as tiles provided along the surface of the tamping tool. These wear-resistant tiles, however, can break off as the tool is used and potentially require replacement or repair of the tool.


It is often difficult to manufacture or repair tamping tools with wear-resistant tiles provided thereon. For example, as shown in U.S. Pat. Nos. 7,726,246 and 5,261,763, typical tamping tools include many wear-resistant tiles that require control and precision location and placement of the tiles during manufacture. Precision placement of the tiles requires expensive labor as well as extended production and brazing time. Additionally, the numerous tiles required can often lead to more repair and replacement of a tool. As individual tiles dislodge from the tool, the entire tool may need to be replaced, even though many of the remaining tiles may still be usable.


In typical tamping tools, wear-resistant tiles are often abutted against each other. As a leading wear-resistant tile shifts or moves (e.g., as it strikes ballast), it imparts a force on adjoining tiles. This force can cause adjoining tiles to fail more quickly or to fail when a leading or adjacent tile fails.


During manufacture of tamping tools with wear-resistant tiles, the wear-resistant tiles are typically brazed onto the tamping tool. When the tiles are abutted against each other, brazed material from the brazing operation of adjacent tiles may spill over into areas that should be kept clean of braze alloys. This spillover of braze materials into adjacent areas can negatively impact the brazing of tiles in those adjacent areas.


A typical tamping tool includes a nose or a top that wraps around one side of a paddle of a tamping tool. Accordingly, the known paddle and tile often require a second braze which can weaken or lead to a weakening of the first braze of the wear tile to the paddle. In addition, a nose wear tile can push off the paddle in one direction during use. Also, in manufacturing, a nose wear tile can be difficult to locate and position relative to the paddle during manufacture, ultimately resulting in longer production times and manufacturing defects. As such, as improved tamping tool is desired.


BRIEF SUMMARY

The present disclosure generally relates to a railroad track ballast tamping tool. The tamping tool may be lowered into ballast underlying railroad tracks and between railroad track ties for performing ballast tamping operations. The tamping tool includes a shank and a paddle coupled to the shank. The paddle comprises at least one top ridge disposed on a top surface of the paddle and a bottom ridge disposed on a bottom surface of the paddle. Top surface wear tiles are coupled to the top surface of the paddle and positioned so as to abut a rear face of the top ridge. Similarly, bottom surface wear tiles are coupled to the bottom surface of the paddle and positioned so as to abut a rear face of the bottom ridge. Nose wear tiles are coupled to both the top and bottom surfaces of the paddle and positioned so as to abut a front face of both the top and bottom ridges, thereby substantially covering a front end of the paddle.


Advantageously, the ridges serve as impact barriers between surface wear tiles and nose wear tiles. During ballast tamping operations, forces absorbed by nose wear tiles are transferred to the ridges (and thus the paddle) instead of adjacent surface wear tiles. Similarly, forces absorbed by surface wear tiles are transferred to a ridge (and thus the paddle) instead of adjacent nose wear tiles. As such, the lifespan of surface wear tiles, nose wear tiles, and the paddle is dramatically increased. The ridges also prevent the spillover of braze materials into adjacent tile locations.


The shape of the nose wear tiles matches a profile of the front end of the paddle. By installing the nose wear tiles as continuous pieces that cover the front end of the paddle, only one braze may be required during installation. Accordingly, the amount of time and cost spent to manufacture and maintain the improved tamping tool described herein is drastically less than that spent on previous tamping tool designs. A single-braze installation of nose wear tiles may additionally provide an increased disposal of carbide at the tip ends of nose wear tiles, which may ultimately allow for larger penetrating tip shapes to be used.





BRIEF DESCRIPTION OF THE DRAWINGS

Various examples of embodiments of the systems, devices, and methods according to this invention will be described in detail, with reference to the following figures, wherein:



FIG. 1 illustrates a top isometric view of an exemplary tamping tool paddle and a portion of a tamping tool shank, according to various examples of embodiments;



FIG. 2 illustrates a top view of the exemplary tamping tool paddle and shank portion illustrated in FIG. 1;



FIG. 3 illustrates a first side view of the exemplary tamping tool paddle and shank portion illustrated in FIG. 1;



FIG. 4 illustrates a second side view of the exemplary tamping tool paddle and shank portion illustrated in FIG. 1;



FIG. 5 illustrates a front view of the exemplary tamping tool paddle and shank portion illustrated in FIG. 1;



FIG. 6 illustrates a rear view of the exemplary tamping tool paddle illustrated in FIG. 1;



FIG. 7 illustrates a bottom view of the exemplary tamping tool paddle and shank portion illustrated in FIG. 1;



FIG. 8 illustrates a side view of an exemplary nose wear tile, according to various examples of embodiments;



FIG. 9 illustrates a top view of the exemplary nose carbide illustrated in FIG. 8;



FIG. 10 illustrates a side view of an exemplary tamping tool, according to various examples of embodiments;



FIG. 11 illustrates a side view of an exemplary tamping tool with wear tiles removed, according to various examples of embodiments; and



FIG. 12 illustrates various views of an exemplary tamping tool, according to various examples of embodiments.





It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary to the understanding of the invention or render other details difficult to perceive may have been omitted. It should be understood, of course, that the present disclosure is not necessarily limited to the particular embodiments illustrated herein.


DETAILED DESCRIPTION

Referring to the drawings, various exemplary embodiments of an improved tamping tool are provided. It is to be understood that the following explanation is merely exemplary in describing the devices and methods of the present disclosure. Accordingly, several modifications, changes, and/or substitutions may be contemplated.



FIG. 1 illustrates an exemplary tamping tool 100. The tamping tool 100 may include a shank portion 102, a paddle 104, and a plurality of wear tiles 106, 108. In some embodiments, the shank 102 and the paddle 104 may be integrally formed. It should be appreciated, however, that in other embodiments, the shank 102 and the paddle 104 may be coupled in other ways, including welding, being detachedly and/or operatively coupled to each other, and/or the like.


The shank 102 and the paddle 104 may be manufactured as a common piece or different pieces coupled together. The shank 102 and the paddle 104 may be formed of a rigid material such as metal (e.g., iron, brass, aluminum, and/or steel), an alloy (e.g., a carbon-based alloy), a plastic, a ceramic, and/or the like. In various embodiments, the shank 102 and/or the paddle 104 may be forged, cast, fabricated, 3-D printed, assembled, and/or the like. The shank 102 and/or the paddle 104 may also be heat treated (e.g., tempered).


In various embodiments, the shank 102 may include an upper portion 110 and a lower portion 112. The upper portion 110 of the shank 102 may be configured to operatively couple to an arm (e.g., arm 118 of FIGS. 10 and 11) of the tamping tool 100. The arm may connect the tamping tool 100 to a rail maintenance vehicle and/or tamping vehicle chassis. In some embodiments, the upper portion 110 of the shank 102 may include the arm of the tamping tool 100.


The lower portion 112 of the shank 102 may couple to a top surface of the paddle 104 as seen in FIGS. 1 and 2. In some embodiments, the lower portion 112 of the shank 102 may extend upwardly from the top surface of the paddle 104. The lower portion 112 of the shank 102 may also extend outwardly at an angle in a rear direction from the paddle 104.


In various embodiments, the wear tiles 106, 108 may include surface wear tiles 106 and nose wear tiles 108. As seen in FIGS. 1-4, 10 and 12, surface wear tiles 106 may be provided (e.g., disposed and/or displaced) on a top surface and/or a side surface of the paddle 104. FIGS. 3, 4, 7, 10, and 12 illustrate that surface wear tiles 106 may also be provided on a bottom surface of the paddle 104. The surface wear tiles 106 may be substantially square, rectangular, and/or another shape and may be configured to lie flatly against a surface of the paddle 104. A plurality of surface wear tiles 106 may be placed adjacently to one another on one or more surfaces of the paddle 104. As shown in FIGS. 3-4 and 10-12, one or more surface wear tiles 106 may also be recessed into the paddle 104. Additionally, and as shown in FIGS. 1-5, 10, and 12, one or more surface wear tiles 106 may be positioned on an outer surface of the lower portion 112 of the shank 102. In some embodiments, the surface wear tiles 106 may include beveled edges.


The nose wear tiles 108, as shown in FIGS. 1, 3-6, 8, 10, and 12, may be provided around a front end (e.g., a nose) of the paddle 104. The front end of the paddle 104 is inserted into the underlying ballast and, as such, may require additional protection provided by the nose wear tiles 108. The nose wear tiles 108 may wrap around at least a portion of the front end of the paddle 104. In some embodiments, and as seen in FIGS. 1-7, a nose wear tile 108 may include multiple nose wear tiles and/or tile portions. Alternatively, a nose wear tile 108 may be manufactured as one piece, such as the nose wear tile 108 illustrated in FIGS. 8-10 and 12.


While the nose wear tiles 108 are shown in FIGS. 1-7 and 9-12 as each having a cross-sectional V-shape, it should be appreciated that the shape of the nose wear tile 108 can be any number of shapes, including a U-shape, a J-shape, a C-shape, a checkmark shape, and/or the like. One or more nose wear tiles 108 may be placed adjacently to one another around the front end of the paddle 104 so as to extend along and substantially cover a width of the front end of the paddle 104. The nose wear tiles 108 may be configured to substantially cover and/or couple with a top surface and a bottom surface of the front end of the paddle 104. Because the nose wear tiles 108 may couple with a top surface and a bottom surface of the front end of the paddle 104, only one braze of the nose wear tile 108 may be required (e.g., as opposed to brazing a first nose wear tile 108 portion on a top side of the paddle 104 and brazing a second nose wear tile 108 portion on a bottom side of the paddle 104). In some embodiments, the nose wear tiles 108 may include beveled edges.


The wear tiles 106, 108 may be made of a wear-resistant and/or abrasion-resistant material, such as tungsten carbide. It should be recognized that one skilled in the art could substitute a variety of rigid materials such as metals, metal alloys and/or mixtures, plastics, ceramics, and/or the like to form the wear tiles 106, 108. The wear tiles 106, 108 may be provided on and/or are otherwise coupled to the paddle 104 in a variety of ways. For example, the tiles 106, 108 may be coupled to the paddle by brazing, soldering, gluing, an adhesive, a fastener, a coupling, and/or the like. While a silver braze or filler metal may be utilized to couple the wear tiles 106, 108 to a surface of the paddle 104, it should be appreciated that any variety of brazes, filler metals, and/or adhesives may be utilized. In some embodiments, the wear tiles 106, 108 may be secured to a surface of the paddle 104 using multiple iterations of brazing.


In various embodiments, the paddle 104 may include and/or otherwise define one or more ridges 114, 116. For example, a top surface of the paddle 104 may include a top ridge 114, whereas a bottom surface of the paddle 104 may include a bottom ridge 116. In some embodiments, the ridges 114, 116 may exist as an impact cushion or barrier between the surface wear tiles 106 and the nose wear tiles 108 on the top and bottom surfaces of the paddle 104.


Referring more specifically to FIGS. 1-7, in various embodiments, the top ridge 114 and/or the bottom ridge 116 may each include a rear face and a front face. For example, a top surface wear tile 106 may be provided on the paddle 104 abutting the rear face of the top ridge 114, and a bottom surface wear tile 106 may be provided on the paddle 104 abutting the rear face of the bottom ridge 116. Additionally, a nose wear tile 108 may be provided around a nose (e.g., a front end) of the paddle 104. In various embodiments, the nose wear tile 108 may abut the front face of the top ridge 114 and the front face of the bottom ridge 116.


In this manner, the ridges 114, 116 may separate the surface wear tiles 106 and the nose wear tiles 108 so as to prevent the surface wear tiles 106 from directly contacting the nose wear tiles 108 during operation. Thus, when a nose wear tile 108 absorbs large forces as it is inserted into and/or tamps ballast, those forces may be transferred through the nose wear tile 108 and to the ridges (e.g., top ridge 114 and/or bottom ridge 116) of the paddle 104 as opposed to being transferred to a surface wear tile 106 directly abutting the nose wear tile 108. The ridges 114, 116 may dramatically increase the longevity of surface wear tiles 106 by reducing the amount of exposure of the surface wear tiles 106 to large (and potentially damaging) forces received by the nose wear tiles 108 during ballast tamping operations.


In some embodiments, the ridges 114, 116 may be integrally formed into top and/or bottom surfaces of the paddle 104. In other embodiments, the ridges 114, 116 may be operatively coupled to top and/or bottom surfaces of the paddle 104. As shown in FIGS. 1-12, the paddle may include one or more top ridges 114 and/or one or more bottom ridges 116.


In various embodiments, one or more wear tiles 106, 108 are provided between the top ridges 114 and/or the bottom ridges 116 of the paddle 104. These wear tiles 106, 108 provided between the top ridges 114 and/or the bottom ridges 116 may be brazed to the paddle 104. Any other wear tile 106, 108 may be brazed to a surface of the paddle 104.


During braze operations, the ridges 114, 116 may further serve as a barrier for preventing braze material from seeping into adjacent spaces where wear tiles 106, 108 may be installed later. For example, as a surface wear tile 106 abutting a rear face of the top ridge 114 of the paddle 104 is being brazed to the top surface of the paddle 104, the top ridge 114 may prevent braze material from flowing into the location abutting the front face of the top ridge 114 into which a nose wear tile 108 is to be installed. In this manner, the top ridge 114 and/or the bottom ridge 116 may keep adjacent areas clean of braze alloy and/or other braze materials, ultimately increasing the structural integrity of the paddle 104 and/or the wear tiles 106, 108.



FIG. 12 illustrates various views of an exemplary tamping tool as described herein (e.g., tamping tool 100). For example, FIG. 12 shows an isometric view 120, a top view 122, a bottom view 124, a front view 126, a rear view 128, a first side view 130, and a second side view 132 of a tamping tool. As seen in FIG. 12, the location at which the shank 102 couples to the paddle 104 may be offset to a side; as a result, the sizing and/or shape of surface wear tiles 106 on the top and/or bottom surfaces of the paddle 104 may vary.


It should be appreciated that while, as disclosed herein, the present disclosure specifically relates to the field of tamping tools for adjusting ballast underlying or adjacent railroad ties and tracks, the present disclosure could be utilized in connection with any variety of tamping or other tools which may utilize wear tiles to help protect and increase the long, useful life of such tools.


As utilized herein, the terms “approximately”, “about”, “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.


It should be noted that references to relative positions (e.g., “front” and “rear,” “upper” and “lower”, “top” and “bottom”, and “side”) in this description are merely used to identify various elements as are oriented in the Figures. It should be recognized that the orientation of particular components may vary greatly depending on the application in which they are used.


For the purpose of this disclosure, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature.


It is also important to note that the construction and arrangement of the system, methods, and devices as shown in the various examples of embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements show as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied (e.g. by variations in the number of engagement slots or size of the engagement slots or type of engagement). The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the various examples of embodiments without departing from the spirit or scope of the present inventions.


While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. Moreover, the above advantages and features are provided in described embodiments, but shall not limit the application of the claims to processes and structures accomplishing any or all of the above advantages.


Additionally, the section headings herein are provided for consistency with the suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically and by way of example, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Neither is the “Brief Summary” to be considered as a characterization of the invention(s) set forth in the claims found herein. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty claimed in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims associated with this disclosure, and the claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of the claims shall be considered on their own merits in light of the specification, but should not be constrained by the headings set forth herein.

Claims
  • 1. A tamping tool comprising: a shank;a paddle coupled to the shank, wherein the paddle comprises: a top ridge disposed on a top surface of the paddle; anda bottom ridge disposed on a bottom surface of the paddle;a top surface wear tile coupled to the top surface of the paddle and abutting a rear face of the top ridge;a bottom surface wear tile coupled to the bottom surface of the paddle and abutting a rear face of the bottom ridge; anda nose wear tile coupled to the top and bottom surfaces of the paddle and abutting a front face of both the top and bottom ridges.
  • 2. The tamping tool of claim 1, wherein the shank comprises: an upper portion for interfacing with a rail vehicle chassis; anda lower portion for coupling with at least one of the top surface and a rear surface of the paddle, wherein the lower portion extends upwardly at an angle from the paddle to substantially match a profile of the paddle.
  • 3. The tamping tool of claim 1, wherein the shank is integrally formed with the paddle.
  • 4. The tamping tool of claim 1, wherein at least one of the top ridge and the bottom ridge is integrally formed with the paddle.
  • 5. The tamping tool of claim 1, wherein the nose wear tile substantially covers a front end of the paddle, wherein the front end is adjacent to the top and bottom surfaces of the paddle.
  • 6. The tamping tool of claim 1, wherein a cross-sectional shape of the nose wear tile substantially matches a cross-sectional profile of the front end of the paddle.
  • 7. The tamping tool of claim 1, wherein the top ridge comprises a plurality of top ridges.
  • 8. The tamping tool of claim 7, wherein the top surface wear tile comprises a plurality of top surface wear tiles, each top surface wear tile abutting a rear face of a top ridge of the plurality of top ridges.
  • 9. The tamping tool of claim 1, the bottom surface wear tile comprises a plurality of bottom surface wear tiles positioned adjacent to each other on the bottom surface of the paddle, each bottom surface wear tile abutting a rear face of the bottom ridge.
  • 10. The tamping tool of claim 1, further comprising a side surface wear tile coupled to a side surface of the paddle.
  • 11. The tamping tool of claim 1, further comprising a shank surface wear tile coupled to an outside surface of the shank.
  • 12. The tamping tool of claim 1, wherein at least one of the top surface wear tile, the bottom surface wear tile, and the nose wear tile is coupled to the paddle via one or more braze operations.
  • 13. The tamping tool of claim 12, wherein at least one of the top ridge and the bottom ridge prevents braze material from entering a tile location abutting the at least one of the top ridge and the bottom ridge during the one or more braze operations.
  • 14. The tamping tool of claim 1, wherein at least one of the top surface wear tile, the bottom surface wear tile, and the nose wear tile is coupled to the paddle via only one braze operation.
  • 15. The tamping tool of claim 1, wherein the paddle is configured to be lowered into ballast underlying railroad tracks and between rail ties of the railroad tracks for performing ballast tamping operations.
  • 16. The tamping tool of claim 15, wherein forces absorbed by the nose wear tile during ballast tamping operations are at least partially transferred to at least one of the top ridge and the bottom ridge.
  • 17. The tamping tool of claim 1, wherein at least one of the top surface wear tile, the bottom surface wear tile, and the nose wear tile is detachedly coupled to the paddle.
  • 18. The tamping tool of claim 1, wherein at least one of the top surface wear tile, the bottom surface wear tile, and the nose wear tile comprises beveled edges.
  • 19. The tamping tool of claim 1, wherein the nose wear tile is a single tile piece.
  • 20. The tamping tool of claim 1, wherein the nose wear tile comprises multiple tile pieces.
  • 21. The tamping tool of claim 1, wherein the nose wear tile is coupled to a front end of the paddle, wherein the front end is adjacent to the top and bottom surfaces of the paddle
  • 22. The tamping tool of claim 1, wherein at least one of the top surface wear tile, the bottom surface wear tile, and the nose wear tile is coupled to the paddle via one or more braze operations at a wear penetration point of the paddle.
  • 23. The tamping tool of claim 1, wherein forces absorbed by the nose wear tile during ballast tamping operations are at least partially diverted from at least one of the top surface wear tile and the bottom surface wear tile.
  • 24. The tamping tool of claim 1, wherein at least one of the top ridge and the bottom ridge at least partially speed up alignment of at least one of the nose wear tile, the top surface wear tile, and the bottom surface wear tile during production.
  • 25. A tamping tool paddle coupled to a shank and comprising: a top ridge disposed on a top surface of the paddle; anda bottom ridge disposed on a bottom surface of the paddle;a top surface wear tile coupled to the top surface of the paddle and abutting a rear face of the top ridge;a bottom surface wear tile coupled to the bottom surface of the paddle and abutting a rear face of the bottom ridge; anda nose wear tile coupled to the top and bottom surfaces of the paddle and abutting a front face of both the top and bottom ridges, wherein the nose wear tile substantially covers a front end of the paddle.
  • 26. A tamping tool paddle comprising: a top ridge disposed on a top surface of the paddle; anda bottom ridge disposed on a bottom surface of the paddle;a top surface wear tile coupled to the top surface of the paddle and abutting a rear face of the top ridge;a bottom surface wear tile coupled to the bottom surface of the paddle and abutting a rear face of the bottom ridge; anda nose wear tile coupled to the top and bottom surfaces of the paddle and abutting a front face of both the top and bottom ridges.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a nonprovisional application of, and claims priority to, U.S. Provisional Patent Application No. 62/322,027 filed on Apr. 13, 2016, the contents of which are hereby incorporated by reference in entirety.

Provisional Applications (1)
Number Date Country
62322027 Apr 2016 US