Patent Grant
7261259
The present invention relates to rail crossings and turnouts and more specifically to an improved frog particularly suitable for mine use.
Rail crossings and turnouts are points where two sets of track cross. The center part of the crossing is sometimes referred to as a frog. Frogs can be cast or fabricated. For heavy use, frogs are sometimes formed from a durable steel such as manganese to increase resistance to wear and impact. Manganese frogs are a standard part of the mining, tunneling and railroad industry.
The rails connecting the switch rails to the frog are called closure rails. A frog has a toe end connected to the closure rail and a heel end at the end of a frog furthest from the switch. The frog point is the area where the running edges of two crossing rails come together. The frog has wing rails, which are two small rails at the heel end of the frog running essentially parallel to the wheel path along each side of the frog point. The wing rails support the wheel of the train car as the wheel crosses the gap at the frog point. The wing rails and the point define an X-shaped pair of grooves or flangeways. The flangeway is a channel that allows the wheel flange of the car to pass. The flangeway allows the wheel flange to maintain continuous contact with the inner surfaces of the frog through the intersection of the rails.
In order to properly guide a passing car over the frog, a guard-rail is typically placed on the opposite rail. A short rail is placed inside of and parallel to the stock rail opposite the point that the wheels pass through the frog.
The width of the frog is called its spread. Different sized frogs are used for rails making various angled turns. Frogs are generally identified by a frog number, which corresponds to the ratio of the length to the sum of heel and toe spreads. Conventional frogs have standard dimensions according to the frog number. Larger numbered frogs are generally used for larger turn radii.
The mining industry presents challenges for rail crossings. Modern mining cars are longer than their predecessors are. Most mine car wheels are fixed and do not turn. Due to the tight curves in the rails in mining operations, the wheels of these longer rail cars cannot follow the turns easily and easily derail when passing through a frog. As the leading wheels of the car move through the frog to the secondary rail, the car is turned in a different direction from that of the original rail. The fixed rear wheels of the car are pushed to the outside of the turn. In an existing frog, the rear wheel may jump the frog and derail the car. Where cars derail, damage may occur to the car and or the load in the car and the impact of the train car wheels on the frog generates early failure of the crossing.
Wing rails and guard rails have been used in an attempt to prevent derailing; however, no frog exists that adequately prevents derailing of longer fixed-wheel cars, such as those used in mines. A need exists for a frog having the ability to maintain the rear wheels of a car and successfully transfer the car through a turnout or crossover on a track. A need exists for a frog with a flangeway having an adequate width and angle to allow the wheel of a train car riding the wing rail across the intersection to stay in contact with the frog until it is supported by the secondary rail.
The present invention addresses these needs and relates to an improved frog having flared segments in each of two opposite flangeways. The improved frog varies in size and turn radius corresponding generally to known frog numbers. Although the frog's dimensions vary by frog number, the ending width of the flangeway is proportionally greater than a corresponding ending flangeway width of a conventional frog.
The frog has an upper surface for supporting a rail car wheel. The flared flangeway comprises a channel that allows a wheel flange of a railway car to pass through the frog. A segment of the flangeway angles away from a point section at a greater angle than that of similar segments of conventional frog flangeways. In an embodiment, the segment's ending width is approximately 3.5 times greater than the beginning width.
Each segment tapers outwardly from a center line of the frog to form a generally triangular perimeter. Together the segments form a generally triangular perimeter. In an embodiment, the angle of the segment wall forms about a 25 degree or about a 30 degree angle with the center line or the point wall. The segments together form about a 50 degree to about a 60 degree angle. In an embodiment having a certain frog number, the ending width of each channel is approximately 5.5 inches.
The present invention's construction comprises walls that are thicker than corresponding walls of conventional frogs. In comparison to conventional frogs, the present invention comprises additional steel in cavities to increase strength and durability. In an embodiment, the frog is unitarily formed of steel, preferably manganese.
The present invention comprises a method for providing an improved rail way frog comprising forming the frog into a predetermined shape having a predetermined length and a predetermined width with thicker walls than corresponding walls of conventional frogs. The improved frog of the present invention is formed with opposite flangeway channels having an ending width greater than a corresponding ending width of a channel in a conventional frog.
These improvements offer enhanced performance over conventional frogs, resulting in a savings of time and expense by rail operators and owners, particularly mines owners and their employees.
Features, aspects, advantages and objects presented and accomplished by the present invention will become apparent and or be more fully understood with reference to the following description and detailed drawings of preferred and exemplary embodiments.
As shown in
The frog comprises a left wing rail 150 and a right wing rail 160 that generally mirror each other and extend from the throat 130. The distance between the throat ends 151, 161 of the wing rails 150, 160 is less that the distance of the opposite ends 152, 162 of the wing rails 150, 160.
The toe ramp 140 cooperates with flangeways 170, 180. The flangeways 170, 180 are joined prior to point 185 and formed from the sides of the wing rails 150, 160. The flangeways 170, 180 diverge after the point 185 and each extend outwardly toward the heel end 110. A point section 190 extends between flangeways 170, 180. Lateral side walls of the point section 190 form each flangeway's second wall 191, 192. The point section 190 is essentially triangular shaped and terminates at the heel end connector near ends 128a, 128b. Each heel end connector near end 128a, 128b is closer to the other than each heel end connector far end 129a, 129b.
The flangeways 170, 180 angle outward as compared to each other. Ends of a flangeway first segment 171, 181 at the throat 130 are closer in proximity to each other than the segment opposite end. The first segment wing rail side wall 178, 188 and the point side wall 191, 192 are approximately parallel to each other. A second flangeway segment 173, 183 has a second segment wing rail side wall 179, 189 at a greater angle to that of the side wall of the first flangeway segment 171, 181 in reference to the point side wall 191, 192. In an embodiment, the angle of the second segment side wall 179, 189 to the point side wall 191, 192 is approximately 25 degrees to approximately 30 degrees. In a preferred embodiment, each second flangeway segment wing rail side wall 179, 189 angles from the respective point side wall 191, 192 at about a 28 degree angle. In an embodiment, the segment side walls 179, 189 form about a 50 degree to about a 60 degree angle to each other. In a preferred embodiment, the angle formed by the second segments is about a 56 degree angle.
In an embodiment, a flangeway second segment end 172, 182 width is approximately 3 to 4 times greater than a beginning width closest to first segment. In a preferred embodiment, the width of each flangeway end 172, 182 is about 3.5 times greater than end closest to the first segment.
One skilled in the art would readily understand that the size and angles of the present invention vary to conform to the pattern and dimensional details of the rail and the radius of the curve. The present invention varies in size, generally corresponding to the size of conventional frogs based on frog numbers.
In
The improved frog of the present invention is cast of steel, preferably, manganese steel. As depicted in
The frog of the present invention is formed such that wheel load is borne at least in part by the rail ties. The thickness of the walls of the at the heel end connector 122, 123 adds stability at the point of re-contact of the wheel of the train car to the second rail. As a consequence of these improvements, the frog supports heavier loads and lasts longer than conventional frogs.
The following example is provided to further describe the invention. One skilled in the art would readily understand that the example would similarly apply to a right hand turn, switch, other crossing, and the like.
In this example, a train car traveling on a first track is switched to a track that is a left turn from the direction of the first track. As the train car is moved from the first track to the second track, the front wheels of the car traverse the frog and change the direction of the car to the direction of the second track. As the fixed rear wheels of the car enter the turnout, the right hand wheel engages the frog. As shown in
The frog optionally works in conjunction with conventional guard railings that work on the wheel opposite the frog wheel to further aid in the prevention of derailings.
The thickness of the walls, the additional steel, and the wide flared flangeways of the present invention have greatly improved performance over conventional frogs, resulting in a savings of time and expense.
One skilled in the art will understand that the description of the present invention herein is presented for purposes of illustration and that the design of the present invention should not be restricted to only one configuration or purpose, but rather may be of any configuration or purpose which essentially accomplishes the same effect.
The foregoing descriptions of specific embodiments and examples of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. It will be understood that the invention is intended to cover alternatives, modifications and equivalents. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
| Number | Name | Date | Kind |
|---|---|---|---|
| 1391226 | Weaver | Sep 1921 | A |
| 1402098 | Shaw | Jan 1922 | A |
| 2377273 | Siebert | May 1945 | A |
| 3764802 | Webster | Oct 1973 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20060081734 A1 | Apr 2006 | US |
