Train traction device and methods

REFERENCES CITED

U.S. Patent Documents

[0001]

1

4,768,312
Sep. 6, 1988
U.S. Patent

5,919,295
Jul. 6, 1999
U.S. Patent

5,305,853
Apr. 26, 1994
U.S. Patent

5,549,343
Aug. 27, 1996
U.S. Patent

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a class of rail traction enhancement devices, traction particles and methods of enhancing locomotive and carriage wheel traction. The device, particles and methods of the invention provide a benefit in reduction of train wheel noise and rail wear.

[0004] 2. Description of Related Art

[0005] Traction and wheel noise have historically been difficult problems in the rail road industry. Inadequate traction wastes energy, disturbs neighbors and passengers, and damages equipment.

[0006] Steel wheels on a steel track are surprisingly slippery. The surfaces are smooth and the actual contact patch between the rail and wheel can be only a square inch. Poor traction can make it difficult for a locomotive to haul large cargos, especially from a start or up a grade. Traction problems are also exacerbated in wet weather and while traveling around corners. Inadequate traction is a major cause of wheel noise and rail wear.

[0007] Slipping wheels cause wear to the track, the wheel and, ultimately to the entire train. As wheels slip, they damage the track and are, in turn, burnished and abraded by the track. The wheels can go out of round or develop flat spots that cause vibrations, damage transported goods and wear on train suspension. Worn track also causes vibrations and wear. Some technicians believe repeated slipping interactions between train wheels and tracks can lead to harmonic wear patterns (corrugation similar to “washboard” patterns on gravel roads) that can present severe vibration problems. Barely detectable wear patterns on a rail surface can result in high frequency vibrations detectable as noise to the human ear. Treatments to the track can increase locomotive traction. Sand has historically been applied in front of the drive wheels to increase traction. Sand application provides extra traction for only the the passage of one train, then it falls aside to accumulate beside the tracks. In Lamba, U.S. Pat. No. 5,919,295, “Locomotive Adhesion Enhancing Material Mixtures” metal oxides are dispensed onto the track in front of driving wheels. This is somewhat of an improvement because the oxides provide more traction by weight than sand. However, this treatment is expensive and provides only brief benefits as it too falls from the tracks. In addition, sand and oxides may reduce electrical conductivity necessary to some electric trains.

[0008] Sometimes traction is lost due to foreign substances, such as grease, on the track. In Fearon, U.S. Pat. No. 4,230,045, “Method and System for Increasing the Track-to-Wheel Friction of the Wheels of a Locomotive for the Motive Power and Decreasing the Rolling Resistance for Trailing Loads”, the track is washed and dried in front of the driving wheels. Liquid cleaning agents are sprayed in front of the driving wheels at very high pressure, then the cleaning agents are removed with a powerful blast of air. This requires complex, heavy, energy consuming and expensive systems to be mounted on the locomotive. This invention provides the traction of a standard clean track, at best.

[0009] One of the major problems associated with inadequate traction on a railroad is noise. Noise can be caused by slippage in a straight section of track that causes harmonic wear patterns, as described above. Even more famous is the noise generated by trains going around curved sections of track. Unlike automobiles, which have differentials to allow independent movement of left and right wheels, trains employ solid axles. Train wheels are paired on the solid axles and must turn together. As a train goes around a corner, the outside wheel travels a longer distance than the wheel on the inside of the turn. Because the wheels must turn together, one wheel must slip. The slipping wheel often creates a screeching noise. Without being limited to one theory, it is believed the wheel slips and grabs repeatedly at a high frequency. The wheel vibrates traversely in a sine wave pattern of starts and stops, slipping across the track as it rings like a bell. This traverse slippage scuffs and wears at the track and wheel.

[0010] One way to minimize to prevent noise and wear while a train goes around a curve is to lubricate one of the tracks. In U.S. Pat. No. 5,305,853 to Ross, “Lubricant Stick Applicator”, an apparatus is mounted to apply a lubricant to train wheels to reduce noise on turns. This invention may minimize noise at the point of application but can leave a residue of lubricant on wheels and tracks that only increases the traction problems previously discussed.

[0011] Trains can be redesigned to eliminate train wheel noise. For example, the Paris metro system has experimented with using pneumatic rubber tires on trains. This works only for light rail applications and has its own set of problems such as flat tires. Trains with magnetic levitation have been experimented with for years. Such trains usually require super cooled electromagnets and are currently envisioned only for high speed light weight applications.

[0012] Wheels can be ground to reduce noise. Wheels can be inspected, using methods well known in the art, to detect flat spots and out of round conditions. Ensuring wheels are perfectly round and that left and right wheels have exactly the same diameter can reduce wear and noise. Apparently, a particular lateral grind to the wheel contact surface can also reduce noise. In U.S. Pat. No. 5,549,343 to Blazer, “Train Tire Profile”, a hyperbolic profile is ground into the train wheel to minimize the lateral oscillations, discussed above, that produce noise and wear.

[0013] Another way to minimize train wheel noise is by grinding the tracks. In U.S. Pat. No. 4,768,312 to Williams, “Rail Grinding Machine”, joints between rail sections are ground to eliminate the noise associated with track joints. Other methods are commonly used to grind the harmonic wear corrugation patterns off of rails to reduce noise. Grinding rails requires expensive machinery, highly trained crews and takes the track out of commission during the grinding process. Rail life is shortened as the grinding process must be repeated periodically. As the harmonic wear patterns are more a symptom than a cause of the problem, a better solution would be to address the ultimate cause of wear and noise—inadequate traction.

[0014] A need remains for an inexpensive way to provide a long term improvement in train wheel traction that will reduce the wear and noise caused by wheel slippage on tracks.

SUMMARY OF THE INVENTION

[0015] The present invention provides methods and devices to increase traction and minimize train wheel noise by application of hard metal particles to the track surface.

[0016] In one aspect, the invention provides a device for application of traction particles to rails. The device includes a grinding wheel, a metal source in contact with the grinding wheel, and a roller. In the working device, the metal source is cut or ground by the wheel to provide metal particles which are applied to rails to be pressed into the rail by the roller. The grinding wheel can be, e.g., a grind stone, carbide cutting wheel or diamond cutting wheel, driven by a motor. The metal source can be harder than the rail, e.g., the metal can be tool grade steel, stainless steel, carbide steel and titanium alloys. The metal source can be directed and urged into the grinding wheel by a feed mechanism such as a slot with a spring loaded push bar. The roller can be a wheel made of a material with a hardness greater than the metal particles.

[0017] The particles of the invention can be of a size and shape appropriate to the task. Factors to consider include, e.g., the hardness of the rail, hardness of the particles, hardness of the wheels, amount of wear on the track, and the amount of additional traction needed. In one embodiment, the particles can range in size, e.g., 0.1 to 2 mm. The particles can be made of any hard metal, for example, tool grade steel, stainless steel, carbide steel and titanium alloys. Optimum materials, sizes and shapes for the particles can be determined empirically by those skilled in the art for the particular traction requirements at hand.

[0018] A guide mechanism can be provided as a component of the device to receive the metal particles and apply them to a rail. In a preferred embodiment, the guide mechanism can alternately apply the particles to a left or a right rail, for example on a curved section of track. In a more preferred embodiment, the guide mechanism can apply the particles to either track or both tracks as desired.

[0019] The method of the invention can include providing increasing traction for train wheels moving over a rail surface by applying metal particles to the rail and pressing the metal particles to become embedded into a surface of the rail. The method of increasing rail traction can be practiced by using the devices of the invention to apply metal particles onto the rail.

[0020] In an embodiment of the method, a metal bar is ground to provide the metal particles. In a preferred embodiment, the metal particles are harder than the rail. Such metal particles can be made from, e.g., tool grade steel, stainless steel, carbide steel and titanium alloys. Preferred sizes for the particles range from about 0.1 mm to about 2 mm. It is preferred that the particles be pressed into the rail by a roller which is harder than the metal particles.

[0021] The device of the invention can be mounted on a mobile frame to move along sections of track continuously treating rails as required. The device can be mounted on a rail road carriage and transported along the track with a locomotive. Alternately, the device can be mounted to a self propelled carriage to treat track independent of a locomotive. In operation, the device can, e.g., grind particles from a metal source (or provide them from a hopper) and guide them for application in a thin continuous layer on a rail as the device is moved along the track. A hard heavy wheel mounted to the carriage behind the particle guide mechanism can then roll over the particles to embed them into the top surface to the rail.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention will now be more particularly described in connection with its preferred embodiments and with reference to the accompanying drawing wherein:

[0023]
FIG. 1 is a schematic diagram of a device to apply hard metal filings to a track.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention provides particles and a device to increase the traction between a train wheel and a track. The methods of the invention, by increasing traction, can reduce train wheel noise and wear on the entire railroad infrastructure.

[0025] Modern locomotives generate huge amounts of torque to move a train, yet the full force is directed to tiny patches of smooth surface contact between the drive wheels and the rail. Slippage often occurs, particularly under starting forces and while climbing a grade. This slippage can lead to noise and wear to the track and wheel. The particles and methods of the invention provide a gripping surface to increase working traction and to dampen, e.g., lateral wheel oscillations that cause wear (e.g., corrugations) and noise.

[0026] Particles of the Invention

[0027] Traction is provided to train drive wheels and coach wheels by applying hard metal particles to the rail road track. Traction is increased because the particles provide a better grip between the smooth wheel and track surfaces. This effect is accentuated when the particles are made up of a hard metal.

[0028] In one aspect, the particles are metal harder than the track to be treated. The hard metal can be of any formulation appreciated by those in the art, such as tool grade steel, stainless steel, carbide steel and titanium alloys. In one aspect, the particles conduct electricity, thereby providing an effective path for grounding of electric trains and electronic train control systems. In a preferred embodiment, the particles range in size from, e.g., about 0.1 mm to about 2 mm. In one embodiment the particles have sharp edges or points. Particles with more than one sharp edge or point are particularly well adapted to the methods of the invention as they are more likely to become embedded in a rail head.

[0029] Particles can be, e.g., ground, filed, or cut, form hard metal stock. A grinder can contact the steel stock and cut or abrade particles for direct application to a track or for storage and later application. The grinder can be a grind stone wheel driven by, e.g., an electric motor. Alternately, the grinder can cut particles from the hard steel stock. For example, a carbide or diamond cutting tool can cut hard metal stock to provide sharp particles of various sizes and with various sharp edges. A variety of grind stones are available on the market that can produce metal particles of various shapes and sizes well adapted to the methods and devices of the invention.

[0030] The Method of Increasing Traction

[0031] In one basic embodiment of the method of the invention, metal particles are applied to the surface of a rail that requires better traction. The particles are then pressed into the surface of the rail. It is preferred the particles are hard and sharp enough that they become embedded in the rail well enough to remain in place during the passage of more than one train.

[0032] In one embodiment, (see, FIG. 1) feed mechanism 1 has a spring 2 which urges metal source 3 against grinding wheel 4. Metal particles 5 fall into and slide down guide mechanism 6 to fall onto rail 7. The metal particles 5 are then pressed into rail 7 by roller 8.

[0033] The metal particles can be applied to the track by any appropriate means known in the art. In one aspect, the particles are applied to the track by sprinkling them from a hopper through a screen or sieve for uniform dispersion by gravity onto the track. In another aspect, the particles are continuously cut or ground from a metal bar to fall upon the track as required. Those skilled in the art can devise a variety of other means to apply particles to a track, e.g., spraying a suspension of particles, squeezing a paste of suspended particles onto an application roller, and the like.

[0034] Particles can be pressed onto the track with enough force that they remain on the track for more than just one train passage. In one embodiment, the particles are pressed into the track with a roller wheel. Such a roller wheel is preferably hard enough that the particles do not become embedded into the roller. The roller should be directed down onto the particles and track with sufficient force, e.g., to ensure the particles become embedded into the track and thus preventing transfer of the particles to train wheels. The particles can be pressed into the track by other means such as by high speed impact during application or by being forced into the track by a hard inclined plate.

[0035] The Track Traction Treatment Device

[0036] The method of the invention can be practiced by any device adapted to apply and press hard particles into a track. The device can include, e.g., a particle source, a way to guide the particles to the track and a roller to press the particles into the track.

[0037] A particle source for a track treatment device can include prepared particles or particles made in real time, e.g., preformed particles stored in a hopper or particles formed in-situ by cutting or grinding from solid stock, as described above in the Particles of the Invention section.

[0038] Particles can be cut or ground on demand from solid stock. For example, square or round stock of tool steel rods can be fed onto a rotating grinder wheel, file or cutting tool. Depending on particles desired, the grinding wheel can be fine or course to adjust the particle size. Cutting tools with a variety of cutting teeth and patterns can be alternately used to provide particles with different sizes, shapes and edge configurations. Particle composition can be quickly changed, as desired, by loading different types of stock, e.g., tool steel, stainless steel, carbide steel, etc., into the grinder/cutter feed mechanism.

[0039] The grinder wheel and/or cutting tools can be driven by any appropriate means such as by an electric motor, a drive belt or shaft from a locomotive, hydraulic drives or pneumatic motors. As used herein, a grinding wheel can include, e.g., any mechanism known in the art to grind, file or cut particles from solid metal stock. In a preferred embodiment, the grinder or cutter is directly driven by an electric motor.

[0040] The grinder/cutter feed mechanism can employ any means, known in the art, to urge the solid stock into the grinder or cutter surface. The feed mechanism can employ the force of, e.g., spring pressure, hydraulic pressure, air pressure, gravity, electromotive induction, a motorized screw, and the like. In one embodiment, the feed mechanism is a preloaded spring that urges the solid stock into the grinder. The amount of pressure from the spring can be adjustable, e.g., by a manual or motorized turn screw that compresses or releases the loading spring as necessary to accomplish the desired grinding pressure.

[0041] As particles are released from the solid stock by grinding or cutting. they can be guided to be received at the surface of the track by a guide mechanism. The guide mechanism can include any guide means known in the art such as spray from the grinder, falling from the grinder, sliding down a chute, conveyers, rolling applicators, and the like. In a particular embodiment, the solid stock is ground such that particles fall onto the top end of a chute. The particles slide down the chute to be directed onto the surface of the track. In a preferred embodiment, one or more chute can be alternately directed to a left rail, right rail or to both. This can be accomplished by a control mechanism to direct the particles to the desired rail(s), e.g., having the chute mounted on a pivot that swings left or right, or by having left and right chutes receive separate portions of the particles as grinding progresses. On a curved portion of track, it can be desirable to apply particles to one rail while applying a lubricant to the other rail in order to retain driving traction without noise or stress on axles.

[0042] In one aspect of the invention, the particles are embedded into the track to provide more than temporary improvement in traction. The particles can be, e.g., hammered, rolled or pressed into the surface of the rail head. The particles can be embedded into the track by the wheels of a passing train. In a preferred embodiment, the particles are embedded into the rail head by rolling a dedicated hard metal wheel (roller) over the particles applied to the track. The roller can be harder than the particles to prevent sticking to the particles, and to enhance the life of the roller. The hard roller surface can dull sharp upper edges of particles, thereby minimizing abrasive effects of embedded particles on wheels of trains that will use the track. The roller can be forced onto the particles and rail with an amount of force required for the desired penetration of particles into the rail depending on factors such as the hardness of the track, hardness of the particles, shape and sharpness of the particles, etc. The roller can be directed onto the particles and rail by the force of gravity, spring pressure, hydraulic pressure, and the like. Particles not embedded into the rail can be blown, vacuumed or brushed off so they won't be embedded by later arriving train wheels.

[0043] The device of the invention can be mounted, e.g., on a rail road carriage, whereby the process of application and pressing can progress along extended lengths of track. The device can include a dedicated rolling frame, adapted to travel along rail road tracks, the frame providing a mounting structure for the grinder or hopper, the guide mechanism and the roller. Such a rolling frame rail road carriage can be propelled through linkage to a locomotive or can include a motor for self propulsion. Alternatively, the components of the device can be functionally mounted to a conventional railroad car or carriage. It can be appreciated by those skilled in the art that the components of the device can be mounted to a frame or carriage in any number of ways, e.g., steel braces, pivoting links, etc., as appropriate to the particular embodiment.

EXAMPLE

Effect of Particles on Wheel/Track Noise

[0044] Particles applied to corrugated rails were found to significantly reduce noise from passing trains.

[0045] Sound level readings were taken as trains passed a straight corrugated section of commuter rail track (see, Table 1). The sound readings were determined at a distance of 10 feet from the track using a sound level meter (Radio Shack® model 33-2055) with accuracy ±2 dB at 115 dB.

[0046] Tool steel was ground on a conventional grinding wheel powered by an electric motor. Metal particles were collected and placed in a hopper having a sieve. A thin dusting of the particles was manually applied to the rail head of the straight corrugated section of commuter rail track.

[0047] Sound level readings were again taken as trains passed the same section of track.

[0048] Data acquired in this experiment indicate an immediate 13 dB reduction in noise from passing trains, or a 16-fold reduction in audio power coming from the trains. The noise reduction was observed over the course of more than one train. The noise reduction remained significant with the passage of several weeks after treatment.

2TABLE 1Wheel/Track Noise Reduction Effect of ParticlesTreatmentReadingsAverageBefore98 dB100 dB98 dB102 dB104 dB100.4 dBAfter86 dB 87 dB 86.5 dB

Train traction device and methods

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