US3140887A - Method and apparatus for applying traction sand to locomotive driving wheels - Google Patents

Description

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METHOD AND APPARATUS FOR APPLYING TRACTION SAND TO LOCOMOTIVE DRIVING WHEELS 2 Sheets-Sheet 1.

Filed June 9, 1961 JOHN F. mama 212 INVENTORS BY QM July 14, 1964 B. P. WALLACE ETAL METHOD AND APPARATUS FOR APPLYING TRACTION SAND TO LOCOMOTIVE DRIVING WHEELS 2 Sheets-Sheet 2 Filed June 9. 1961 gm A L ZCUHO 3% W U EEMW. A wa m 6mm mw fifi w surface of a revolving locomotive wheel.

United States Patent 3,140,887 METHOD AND APPARATUS FOR APPLYING TRACTHGN SAND T0 LOCOMOTIVE DRIV- ING WHEELS Burgess P. Wallace, Brooklyn, and Ronald E. Melcher, Camhria Heights, N.Y., and John F. Loertscher, J12, Wayne, N..li., assignors to Whitehead Brothers Company, New York, N.Y., a corporation of New Jersey Filed June 9, 1%1, Ser. No. 116,140 5 Claims. (Cl. 291-1) This invention relates to new methods and apparatus for increasing the coefficient of friction between the metal wheel of a locomotive and the surface of the rail on which it operates.

The object of this invention is to provide an improved method and apparatus for using very small quantities of sand as a material to increase the coefficient of friction between locomotive driving wheels and the rails. Another object is to efficiently utilize sand as a means of increasing the driving efficiency of locomotives.

The art has long sought some efiicient means for increasing the driving emciency of locomotives, particularly under conditions of wet rails, during winter travel and at the point of starting. Many different types of apparatus and many different methods have been attempted. Uniformly these methods and apparatus have been unsuccessful. Some of these different ideas are shown in US. Patent No. 747,823, US. Patent No. 1,730,717 and in German Patent No. 448,830. None of the disclosures of these patents, insofar as method or apparatus are concerned, are in practical use today. The reason for this lack of use lies in the fact that these devices and methods simply do not work. Experimental evidence indicates that sand or sand grains, as eroded from an artificial sandstone or composite bar of sand which is held together with any type of binder, simply will not adhere to the This is particularly true when it is considered that the locomotive wheel is turned at a speed of approximately 100-156 rpm. This is the equivalent speed in miles per hour of about 14 mph. The adhesion between the sand grains scraped off the bar or even if loose sand is fed to the wheel, is virtually none. Almost all of the sand is thrown off at a tangent and little, if any, lodges between the locomotive tire and the track.

Experimental evidence has indicated that even very finely pulverized sand, for example sand passing through a 200 mesh screen formed into a composite bar, when applied to a revolving locomotive wheel, the sand will not adhere to the wheel. Furthermore in this type of sand bar or the other sand bars which have been tried by the prior art, it is found that there is a pronounced glazing or polishing action at the face of the bar which results from the wearing of the locomotive wheel on the surface of the bar. Accordingly the composite bar is no longer capable of being surface eroded. No particles of the sand come off and therefore no anti-friction material adheres to the turning locomotive tire.

Yet the art has consistently made this kind of attempt to apply some form of anti-friction material to the locomotive wheels in order to increase traction. German Patout No. 448,830 mentioned above is illustrative of the type of thinking which has been employed and which has been found to be uniformly unsuccessful. Thus, in that patent a traction sand bar is provided Which is eroded by a fluted wheel turning against the bar. The fluted wheel acts as a file or an eroding member which scrapes off some of the abrasive material and delivers it to the locomotive wheel. However, the material will not adhere to the tire since there is simply nothing there which will hold it on the rapidly rotating surface.

Other prior art patents disclose the application of silica or pulverized quartz so finely pulverized as to be in colloidal form. The colloidal silica is compounded in the form of gels or sprays and is applied to the track ahead of the driving wheels, to the wheel itself, or to either surface. The silica or other abrasive material must be in colloidal form to be applied by spray, straight liquid delivery or by a wick-wiping arrangement.

The application and use of such colloidal ground silica, colloidal calcium carbonate or any other colloidally suspended solid, creates a very serious handling problem. Such solids, gels or sprays must be protected from freez ing. In using such material in the winter months, when increased traction is most often necessary, the liquid'will freeze if the container in which it is stored is not heated. Even if heating means are provided if the material is sprayed on the rails or is somehow applied to the rails, which are at temperatures far below freezing, the material immediately freezes creating an ice film. The ice film on the rail of course is directly the opposite result to that which is required in order to increase the traction or driving efficiency of the locomotive wheels.

Other colloidal materials have been suggested for use in suspensions of alcohols, or in other non-freezing materials. To be effective, these must be applied to the rail in such a way as to dry prior to the time the driving wheel contacts them. This eliminates the possibility of such a material being applied just before the driving wheel meets the track because no drying could be obtained in the small amount of time between application and the driving wheels contact with the coated rail. In fact, it has been demonstrated that the application of colloidal silica suspended in alcohol to a track is valueless to the locomotive applying the silica in a volatile solvent form and the material only becomes effective at some subsequent time when drying has occurred. Thus it is effective principally for the locomotive following the applying locomotive and then only after some prolonged time interval. This of course does not meet the problem, and this attempted solution has not gone into any practical use.

For many years, and currently, the accepted practice has been to use ordinary dry, free-flowing silica sand for increasing the friction between the driving wheels and the track. As simple as this application is, there are serious disadvantages to the practice and to the use of this material. For example the sand is normally delivered from a hopper located in the locomotive through a pipe which is placed in a position immediately ahead of the juncture between the locomotive driving wheel and the track. Usually the pipe delivering the sand is aimed directly at the junction of the wheel and the rail. A very much larger volume of sand is delivered than is actually necessary because it is well known that most of the sand is wasted by falling off the rail or by being blown away before the wheel comes in contact with the rail. This blowing away of the sand is materially affected by the fact that a moving train creates air drafts which are of sufficient force to cause the sand to be largely blown away from its effective point.

is substantially that of 200 mesh silica flour.

Another difficulty is that the pipe which delivers the sand is often knocked out of line and a substantial amount of maintenance work is required in order to keep the sand pipe in proper alignment so as to deliver the sand to the precise point of contact between the locomotive wheel and the track. Of course if the sand delivery pipe is not properly aimed, the sand will not hit the track at all, and the sand is therefore completely useless in increasing the traction of the locomotive wheel on the track.

Because of the above mentioned diificulties large volumes of sand must be carried by the locomotives and must be used. This large volume is very ineffective and the deposit of the large quantities of sand on the track bed creates serious maintenance problems. In fact it is well known that such sand is often swept up into and through the intakes of the diesel engines. The sand gets into the diesel fuel causing serious wear on piston rings and cylinder walls. Additionally the sand, in certain points such as stations, where sand is often applied in order to increase the starting traction, builds up to the point where it is necessary to clean the track bed.

With the above problems and the objects of this invention clearly in mind this invention is briefly as follows. We have determined that very few sand grains are actually necessary to obtain the maximum friction between the 10- comotive tire and the track. We have also found that the sand grains must adhere to the revolving locomotive tire or wheel and be reduced to fine silica powder in situ while the wheel is in motion. The sand grains then become highly effective as a friction producing agent and very little of their efficiency is lost. Only a small quantity of sand is required since virtually all of it is utilized.

Briefly, the method of this invention involves depositing said grains on the locomotice wheel at a substantially fixed rate and immediately crushing the sand grains so deposited to a degree of fineness similar to silica flour. For some reason, which is not completely explainable, the material which has been freshly crushed will remain on a spinning locomotive wheel in proportions which are greatly in excess of what might be expected and will so remain on the locomotive wheel until the wheel rolls over the track, thus providing the added traction which is often essential.

The apparatus which is preferred according to this invention is a means for feeding sand to the moving surface of locomotive driving wheels and causing the sand to be crushed by a hardened steel crushing wheel positioned adjacent the point of delivery of the sand in the direction of movement of the locomotive wheel. The crushing wheel is preferably spring-loaded with sufficient pressure to cause the sand grains to be crushed to a fineness which It is this particular mesh which exhaustive studies have indicated provides the greatest amount of traction. Larger grains have a tendency to bounce and to be thrown away from the surface of the wheel prior to the time the wheel engages the track. However, freshly crushed sand grains have a tendency to stick to the locomotive wheel and will so remain on the wheel until after the Wheel engages the track.

Other objects and features of this invention will become more apparent in the discussion which follows below when taken with the drawings in which:

FIG. 1 is an elevational view illustrating a preferred form of this invention;

FIG. 2 is a cross-sectional end view of the device illustrated in FIG. 1 taken on the line 2--2 of FIG. 1;

FIG. 3 is a perspective of a sand delivery spout in accordance with the teachings of this invention;

FIG. 4 is a partial elevation of an alternate form of this invention employing a sand bar;

FIG. 5 is a cross-sectional plan view taken on the line 5-5 of FIG. 4;

FIG. 6 is another embodiment of the device of this invention illustrating the means for removing the sanding device when this is not needed;

FIG. 7 illustrates another embodiment of this invention; and

FIG. 8 is a cross-sectional plan view taken on the line 88 of FIG. 7.

Referring now to the form of the invention illustrated in FIGS. 1 and 2, it will be noted that the locomotive wheel 10 rides on the tread. of normal supporting rail 12 in the usual manner. A sand box 14 filled with such sand as is normally used for sanding purposes is positioned above the wheel 10 and is carried by the frame 16 of the locomotive (not shown). A valve (not shown) would normally be provided for the engineer to open the passageway 18 when sanding is desired. The sand is delivered through passageway 18 to a spreading nozzle 20 such as that illustrated in FIG. 3. The purpose of the spreading nozzle 20 is to insure that the sand grains are evenly spread across the driving surface 22 of the wheel 10. Furthermore, the nozzle 20 serves the purpose of delivering the sand grains directly adjacent the point at which crushing wheel 24 rests on driving surface 22 of wheel 10.

Wheel 24 is mounted on the frame 16 by means of a pivotal connection 26 which joins lever 28 to arm 30. The wheel 24 is carried on shaft 32 and is completely free to rotate thereon. Anti-friction bearings are used to insure that the rotation of wheel 24 is as free as possible. Springs 34 urge the lever 28 towards the wheel 10 with an amount of force sufficient to cause the Wheel 24 to crush the incoming sand grains uniformly to a size about that of 200 mesh silica flour.

Our investigations have shown that if a very few dry silica grains are crushed against the revolving driving sur .face 22 of locomotive wheel 10 prior to its contact with the rail 12, for some reason the crushed grains will adhere very tightly to the locomotive wheel 10. There may be many reasons why this adhesion occurs. Two possible reasons are as follows: A strong electrostatic charge is induced on the surface of a freshly broken sand grain and the crushed or powdered particle will adhere to the wheel 10 due to this electrical charge. Another possibility is that the silica grains which are crushed in situ against the locomotive Wheel 10 create sharp particles which will penetrate the micropored surface of the wheel 10 and become sufiiciently embedded therein to remain thereon until the surface 22 of the wheel 10 contacts the rail 12.

However, regardless of the precise reason for this phenomenon, we do know that this phenomenon occurs, and that a very small amount of sand, if properly crushed, gives a much greater traction force than has been available before with normal methods of applying sand to locomotive wheels.

The sand may be fed to the surface 22 by any suitable means and in any suitable form. It may be dry, loose sand or it maybe in the form of a bar such as that illustrated in FIGS. 4, 5 and 6. In the modifications illustrated in FIGS. 4, 5 and 6 a friable bar 36 of previously prepared bonded together sand particles is positioned in a holder 38 which is in turn carried on the frame 16 of a locomotive (not shown). A solenoid 40 is provided having a plunger 42 which extends into holder 38 sufficiently far to engage bar 36. When sanding is desired, the engineer actuates solenoid 40, causing plunger 42 to be withdrawn sufficiently far to permit the bar 36 to drop down through holder 38 and into contact with the surface 22 of wheel 10. The rotation of wheel 10 against the bar is sufiicient to erode away particles of sand and cause them to be introduced to the crushing effect of crushing wheel24.

One advantage which accrues from using the bar 36 is that it eliminates the difficulties had with loose sand. Moisture tends to cause the loose sand to lump together and in freezing weather creates serious problems if the sand freezes and does not flow freely. will eliminate that kind of trouble.

The modification illustrated in FIG. 6 employs the same kind of holder 38, solenoid 40 and plunger 42, but this is also provided with a lever 44 pivoted about a stud 46. One end of lever 44 is slotted and carries within it a pin 48 which is rigidly attached to holder 38. Holder 38 is vertically movable within the frame 16. An air valve 50 is provided which has a plunger 51, one end of which is attached to the end of lever 44 opposite to the slotted end. The engineer can operate the valve 50 to cause the lever 44 to pivot about its pivot point 46 causing the holder 38 to be raised, thus removing the sand bar 36 from contact with the surface 22 of wheel 10.

Another alternate embodiment of this invention is illustrated in FiGS. 7 and 8. In this embodiment the crushing wheel 24 is carried within a closed housing 52. The housing 52 has a flaring passageway 54 formed therein as shown in FIGS. 7 and 8. A flexible hose 56 attached to a supply of sand (not shown) carries the sand to the surface juncture between surface 22 of wheel and crushing wheel 24. The housing 52 is mounted on the frame or the truck of a locomotive by the stud 58 and spring 60 as shown. The device has the general appearance of a caster and as such is free to rotate sufficiently so that crushing wheel 24 will accurately track itself on surface 22.

Both the crushing wheel illustrated in FIG. 1 and the remaining figures can be arranged to be retracted when not in use if that is desired. Simple arrangements similar to that employed for removing the sand bar 36 in the modification illustrated in FIG. 6 could be interconnected so that both the sand supplying means and the crushing wheel 24 could be removed and applied simultaneously.

The point of application of the sand and crushing point may be at any convenient location provided the crushing occurs prior to the wheel 10 contacting track 12. Different locomotives will require that the device of this invention be located at different points and the position indicated in the drawings is for illustrative purposes only.

While in the embodiments illustrated in the figures, the crushing means has been illustrated as a wheel 24, it will be appreciated that any suitable type of crushing means, for example a brake shoe which would be stationary but positioned a small distance away from the surface 22 of wheel 10, could be employed. The requirement simply is that some means he provided at a point which will intercept the sand which is supplied to the surface 22 before a significant amount of that material has been lost from the surface of the wheel and will exert a suflicient crushing action so that the grains of sand deposited are substantially crushed to something of the order of 200 mesh or finer. We do not intend that we be bound simply by the embodiments illustrated with respect to either the mode of applying the sand to the surface 22 or to the means by which the sand is crushed. We prefer, however, to be limited solely by the scope of the appended claims.

Having described the various embodiments of this invention it would perhaps be well now to discuss the type of sand which is best employed to obtain the maximum advantages hereof. We have found that material which is coarser than 6 mesh to 12 mesh silica sand has a greater tendency to bounce away from the wheel prior to the time any crushing action can be effected. Therefore we preferably employ sands which are less coarse than 12 mesh. We find, however, that when sands of 40 mesh or finer are employed there is virtually no bounce and substantially all of the material receives some crushing action. By adjusting the pressure of the crushing wheel 24 to produce a material which, after crushing, is about 200 mesh or finer, we find that from between 44% to about 80% of the material is retained and is effective to increase the traction.

The most suitable materials are those which are from 70 mesh to 140 mesh and the preferred compositions of The sand bar 36 6 traction sand should include a major proportion of these mesh sizes in order to obtain the maximum efl'iciency.

Actual tests using a 140 mesh sand applied to a revolving locomotive wheel traveling at about .14 miles per hour and. using a crushing pressure of about 100 pounds per square inch, We found that about 94% of the material was crushed to a fineness of 200 mesh or finer and that about of the material was retained on the wheel. This represents an efficiency which is greatly in excess of anything which has previously been available before and constitutes a substantial answer to the problems of sanding locomotive wheels to improve traction.

The total amount of pressure which should be used to force the crushing wheel 24 against the wheel should be the minimum possible in order to crush over 50% of the sand mixture being employed to a fineness of about 200 mesh or less. This figure can he arrived at depending upon available sand supplies and keeping in mind the discussion above with respect to the sand particles size distribution which gives the best results.

If a sand bar such as 36 is employed then any suitable binder which is easily eroded is useful. Great care should be taken to make sure that the binding material is not so strong that the bar 36 will be polished or glazed in use. At the same time the bar 36 should break down readily to produce a single layer of sand on the wheel 10 as it revolves Without any substantial glazing or polishing action being set up on the surface of the bar by the action of the locomotive wheel. To assist in the breakdown a spring force can be employed to force the bar against the wheel 10, which force will depend on the binder used as well as the grain size of the sand.

Such a bar might be comprised of one of the following types of materials. 900 grams of sharp silica sand which has particles predominantly in the l00140 mesh range is mixed with 9 grams of Silicate K, which is Du Ponts trademark for a silicate compound, and 18 grams of Water. The bar is rammed into mold of suitable shape, such as the square shape shown in the figures and baked at 400 F. overnight. Such a bar i found in use to be sufliciently strong to permit handling and yet friable enough to break down with a minimum amount of pressure being exerted on it forcing it toward the wheel 22. If the bar feeds downwardly gravity will be enough to cause breakdown.

Various other types of bars using similar materials are satisfactory provided they meet the basic requirements which have been set forth above.

We have described in detail above a method and several different forms of mechanical embodiments of our invention. It is intended that the above disclosure sets forth our preferred mode of practicing out invention. However, it will be apparent to those skilled in the art that modifications can be made which do not depart from the spirit of our invention or from the scope of the appended claims.

We claim:

1. A method of improving the traction between the driving surface of locomotive wheels and the tread of the supporting rail which comprises depositing sand particles of various sizes on said driving and revolving surface of said wheels and immediately adjacent the point of deposit of said sand particles on said surface, subjecting said particles to a crushing force on said driving and revolving surface sufiicient to crush the major proportion of said particles to cause said crushed particles to remain on said driving and revolving surface until said particles are interposed between said surface and said rail tread.

2. The method of claim 1 in which said sand is deposited in the form of loose, dry particles.

3. The method of claim 1 in which said sand is deposited on said wheels by said wheels breaking down a bar of sand grains friably bound together, which bar is forced against said surface.

4. Apparatus for sanding a locomotive wheel comprising feeding means fordepositing a layer of sand particles on said Wheel and roller means adjacent to and driven by said Wheel for crushing said sand particles.

References Cited in the file of this patent UNITED STATES PATENTS Wilson Dec. 22, 1903 8 Cox et al. Nov. 1, 1938 Moon Oct. 31, 1939 Campbell et a1 Apr. 16, 1940 Havill May 5, 1942 Davis Oct. 26,1943 Canetta June 27, 1944 Foster Oct. 6, 1953 Charp Aug. 8, 1961

Claims (1)

1. A METHOD OF IMPROVING THE TRACTION BETWEEN THE DRIVING SURFACE OF LOCOMOTIVE WHEELS AND THE TREAD OF THE SUPPORTING RAIL WHICH COMPRISES DEPOSITING SAND PARTICLES OF VARIOUS SIZES ON SAID DRIVING AND REVOLVING SURFACE OF SAID WHEELS AND IMMEDIATELY ADJACENT THE POINT OF DEPOSIT OF SAID SAND PARTICLES ON SAID SURFACE, SUBJECTING SAID PARTICLES TO A CRUSHING FORCE ON SAID DRIVING AND REVOLVING SURFACE SUFFICIENT TO CRUSH THE MAJOR PROPORTION OF

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