Patent Grant
10233594
None.
The present invention relates to a railroad track and related switching assemblies.
The present invention relates to a switching assembly for a railway switch and rail arrangement. A railway switch is employed where one track diverges from another. This invention relates to a switch point guard casting for use adjacent the switch point of railway switches in trackwork.
Typically, railroad switching components are some of the highest maintenance portions of a railroad track arrangement as they must endure repetitive impact and stress, as well as extreme inertial forces attendant to lateral disposition of the running wheels and the loads they bear.
The switching rail of a railway switch assembly includes a tapered rail portion which terminates into a thin end point for intercepting and switching the wheels of rolling stock from one rail onto another.
Because such switch point guards engage the wheel flanges at an angle and urge the wheel toward a new route as it proceeds through the switch region, they experience considerable wear due to the repeated contact between the moving wheels and the wheel engaging surface of the guard rail. These castings are designed to capture the wheel and direct it through the switching zone.
In prior art arrangements, switch point guards used a simple, straight lateral surface to urge the wheels into and through their required course through the switching region. In such arrangements, such switch point guards also carried the risk of derailment because their lateral surfaces rub against the engaging wheel and can cause the wheel to ride up the lateral surface, which may lead to a raising of the wheel through a ramping effect as the side of the wheel creeps up the side of the casting. This causes either violent re-leveling of the wheel as the friction of the wheel against the casting gives way to gravity (leading to repetitive impact events that wear the track work and wheels alike) or, in extreme cases, to derailment should the wheel be raised to a point where it loses the capture of the wheel flange.
It is also best to provide a uniform, secure wheel path that distributes load and reduces wheel and guard wear, while reducing the risk of wheel ride-up and derailment.
The embodiments of the invention described herein address the shortcomings of the prior art.
In general terms, the invention may be described as including a switch guard casting, a switch guard assembly for a railway intersection, as well as a rail intersection design and a switch guard assembly therefor.
The present invention may be used for single and multiple switches as will be appreciated from the description and drawings.
The present invention thus provides several concomitant advantages over the prior art. The system of the present invention allows the required capture and guidance of the approaching wheel as it is presented while travelling through the switch region.
In addition, the switch guard casting and its arrangement also allow the engaging surface of the approaching wheel to be guided through the switch region with reduced risk of ride-up along a substantial portion of the run-through distance such that risk of violent re-leveling or derailment is substantially reduced.
The present invention also includes a switching system which may be assembled as a complete unit at a manufacturing site and transported to its intended installation site. This allows for greater control of manufacturing costs and allows the operator to obtain a completed switching assembly that may be produced using relatively small and simple frog castings that can be installed on site.
In operation, the system of the present invention also provides for a secure wheel path and it accepts and allows the wheel to move through the respective intersecting region.
Rail crossing systems of the present invention may be incorporated with canted rail systems that allow for speeds as high as 50-60 mph where desirable.
The several aspects of the present invention may be summarized as follows.
In general terms the present invention includes a switch guard casting, switch guard assemblies and a panel arrangement, as well as a crossing constructed thereby.
Switch Point Guard Casting
In general terms the present invention includes a switch point guard casting comprising a main line body portion having a lateral guide surface, the lateral guide surface having, in series: (a) an entry section defining an entry section curved line; (b) a central section defining a substantially straight line; and (c) an exit section defining an exit section curved line.
The entry section curved line and exit section curved line may be of any curvature, though preferably are selected from the group consisting of continuous curvature lines and progressive curvature lines. It is most preferred that the entry section curved line and the exit section curved line are selected from the group consisting of continuous curvature lines with a radius in the range of from about 40 feet to about 150 feet; though the entry section curved line and the exit section curved line may be selected from the group consisting of progressive curvature lines with radii varying in the range of from about 40 feet to about 150 feet.
Switch Point Guard Casting and Support
The present invention also includes a switch point guard casting and associated support, adapted to be attached to a series of railroad ties, comprising: (a) a switch point guard casting having main line body portion having a lateral guide surface, the lateral guide surface having, in series: (i) an entry section defining an entry section curved line; (ii) a central section defining a substantially straight line; and (iii) an exit section defining an exit section curved line; and (b) a tie plate attached to two of the railroad ties; and (c) a support piece attached to the switch point guard casting and adapted to be affixed to the tie plates.
The entry section curved line and the exit section curved line may be as described above.
Typically, the support piece will be in the form of a bridge-shaped piece adapted to be attached to the switch point guard casting and adapted to be affixed to respective tie plates of two corresponding ties, while allowing a central tie to extend therebetween.
Full Gage Railroad Panel with Switch Point Guard Casting and Support
The invention also includes in its preferred embodiment a full gage railroad panel comprising a switch point guard casting and support, adapted to be attached to a series of railroad ties, comprising: (a) a railroad switch panel comprising a series of railroad ties supporting a railway switch arrangement of sufficient size to accommodate the full gage of a railroad track, the track comprising a running rail; (b) a switch point guard casting having main line body portion having a lateral guide surface oriented toward the running rail, the lateral guide surface having, in series (i) an entry section defining an entry section curved line curving away from the running rail; (ii) a central section defining a substantially straight line parallel to the running rail; and (iii) an exit section defining an exit section curved line curving away from the running rail; and (c) a tie plate attached to two of the railroad ties; and (d) a support piece attached to the switch point guard casting and adapted to be affixed to the tie plates.
The entry section curved line and the exit section curved line may be as described above.
In accordance with the foregoing summary, the following describes a preferred embodiment of the present invention which is considered to be the best mode thereof. With reference to the drawings, the invention will now be described in detail with regard for the best mode and preferred embodiment.
It is preferred that the curvature of entry/exit regions 2B and 2C be identical. The curvatures of the entry/exit regions may be continuous or progressive. In the case of continuous curvatures, the radius of the curvature will typically be in the range of from about 40 feet to 150 feet, although a radius of approximately 100 feet is preferred as it provides a smoother wheel path transition as the wheel enters the guard flare region. It is preferred that the switch point guard has a circular curve entry/exit region with a minimum radius of 50 feet.
In an alternative embodiment, the curvature of the entry/exit regions 2B and 2C may be progressively curved, the respective curvature of a series of sub-regions increasing as they progress from the end of the central region 2A to the respective ends of the casting.
This view shows central region 1A and entry/exit regions 1B and 1C. In this embodiment, the central region 1A is straight, and typically will be in the range of 16±4 inches in length though other lengths may be used depending upon the specific application. The entry/exit regions 1B and 1C are curved, and typically will be in the range of 20±6 inches in length though other lengths may be used depending upon the specific application. In this embodiment, entry/exit regions 1B and 1C are flared such that the deflection away from the straight line represented by rail-facing side 2A of central region 1A is about 1 9/16 inch, and this deflection may vary with each variation, though the typical deflection ratio is normally in the range of 20:1 to 15:1.
It will also be appreciated that the curved surfaces 2B and 2C allow for a somewhat tighter channel to be presented to the wheel, which lends greater wheel security while best resisting wheel lifting and potential derailment.
The preferred adjustable switch point guard of the present invention may incorporate several new design features that have proven to provide improved performance. The switch point guard preferably may have a relatively longer overall guard bar length of about 8 feet, with relatively longer flare lengths; i.e., each end being about 4 feet. The switch point guard of the present invention may also feature a relatively reduced flare entry angle of a 20% reduction (i.e., broadly in the range of 15%-25%). The raised guard bar height may be 5/16 of an inch higher than industry standards, giving increased guarding surface of up to a 50% increase.
Relatively larger diameter mounting bolts of 1⅜″ diameter are preferred as is the use of improved bolt tightness of 1800 ft./lbs. The fixtures preferably are fittings commercially available such as Nord-Lock washers.
The outside handling holes preferably are balanced for safety purposes.
The switch point guard has been found to provide improved service life; i.e., (4) ⅛″ wear cycles.
The switch point guard's support structure of the present invention may preferably be prepared from a durable one-piece cast steel body casting. The arched design not only provides strength to the assembly but it allows for installation on and over an existing center gage plate and with clearance for the existing rail brace assembly. The outside plates are pre-set to the industry standard 42″ spacing which provides ease of installation on right-hand or left-hand new and existing switches. The increased height of the guard bar which provides a substantial increase in the true vertical guarding surface area. The preferred switch point guard will not have a traditional beveled end flare so as to further reduce the likelihood of wheel climbs. The three top mounted indexing inserts allow the manganese steel guard bar to be easily adjusted in track without disassembly providing four ⅛″ wear cycles. The reduced flare entry angle provides less radical wheel deflections thus reducing lateral impact loads. The mounting bolts preferably are H.T.Hex Head 1⅜″ dia. Grade 8 and are factory torqued to 1800 ft./lbs. and secured with Nord-Lock Washers.
While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for the purposes of exemplification, but is to be limited only by the scope of the attached claims, including the full range of equivalency to which each element thereof is entitled.
The following patent documents generally describe switch point guard arrangements, and such references are hereby incorporated herein by reference:
| Number | Name | Date | Kind |
|---|---|---|---|
| 690597 | Meader | Jan 1902 | A |
| 910027 | Stickel | Jan 1909 | A |
| 1161741 | Smoter | Nov 1915 | A |
| 1163431 | Maranda et al. | Dec 1915 | A |
| 1230533 | Stiles | Jun 1917 | A |
| 1463943 | Fallon | Aug 1923 | A |
| 1481765 | Wentling | Jan 1924 | A |
| 1872848 | Told | Aug 1932 | A |
| 3026074 | Kern | Mar 1962 | A |
| 3063641 | Frey | Nov 1962 | A |
| 4355776 | Rydin | Oct 1982 | A |
| 4386751 | Meyer | Jun 1983 | A |
| 4566630 | Keiper, Jr. | Jan 1986 | A |
| 4738418 | Farrell | Apr 1988 | A |
| 5115970 | Rice et al. | May 1992 | A |
| 5169064 | Rice et al. | Dec 1992 | A |
| 7137601 | Christ et al. | Nov 2006 | B2 |
| 8714092 | Heitzenrater | May 2014 | B2 |
| Entry |
|---|
| Switch Point Guard, www.voestalpine.com/nortrak, web page. |
| Switch Point Protectors & Guards, www.harmersteel.com, web page. |
| Switch Point Guards, www.rrtools.com, web page. |
| Guard Rails, Unitrac Railroad Materials, Inc., catalog. |
