US3497403A - Surface hardening of rails - Google Patents

Description

1970 I o. A. RUTHERFORD ETAL SURFACE HARDENING 0F RAILS Original Filed Oct. 30, 1963 4 Sheets-Sheet l I INVENTORS. DAVID A. RUTHERFORD ROBERT J. M WlLLlAMS BY Zlfal/ue ,4 ATTORNEYS 4, 1970 D. A. RUTHERFORD ETAL 3,491,403

summon HARDENING 0F RAILS Original Filed Oct. 30, 1963 4 Sheets-Sheet 2 mm m MO D NH M E -l VHW WU WW R V 5 m N mu m M w & M vm m Q wv MW L Q3 we QM mm... 1. mm m NN 3 52:

ATTORNEYS Feb. 24, 1970 o. A. RUTHERFORD ETAL 3,497,403

SURFACE HARDENING OF RAILS Original Filed Oct. 30', 1963 4 Sheets-Sheet 3 INVENTORS. DAVID A. RUTHERFORD ROBERT J. M WILLIAMS ATTORNEYS Heb. 24,1970 o. A. RUTHERFORD ETAI- 3,497,403

SURFACE HARDENING OF RAILS Original Filed Oct. 30, 1963 4 Sheets-Sheet 4 FIG. 7

INVENTORS.

DAVID A. RUTHERFORD ROBERT J. M WILLIAMS ATTORNEYS 3,497,403 SURFACE HARDENING F RAiLS David A. Rutherford and Robert J. McWiliiams, Pueblo, Colo., assignors to Abex Corporation, New York, N.Y., a corporation of Delaware Original application Oct. 30, 1963, Ser. No. 320,193, now Patent No. 3,300,197, dated Jan. 24, 1967. Divided and this application July 25, 1966, Ser. No. 567,590

Int. Cl. C21d 1/06, 1/78 U.S. Cl. 148-446 2 Claims ABSTRACT OF THE DISCLOSURE Method of simultaneously surface hardening a pair of steel railroad rails by heating the surfaces of the rail heads above the critical temperature for hardening steel and at the same time heating the webs and bases to a temperature below said critical temperature, and quenching the rail head surfaces below the critical temperature and the webs and bases to lower their temperature.

This application is a division of application Ser. No. 320,193, filed Oct. 30, 1963, now Patent No. 3,300,197.

This invention relates to a method of surface treating railroad rails, and more particularly to surface hardening the head of a rail.

Railroad rails have been surface treated heretofore by applying heat to the top surface of a single rail clamped to a stationary bed with a movable flame head traversing above the top surface of the head of the rail. After the head of the rail had its top surface quenched, the rail, in most instances, was so distorted that the rail had to be subsequently straightened in a straightening machine. Accordingly, an object of the present invention is to increase the efficiency of rail treating operations by heat treating in a novel fashion a pair of rails simultaneously. Another object of the invention is to eliminate the distortion necessitating straightening of the rails by a novel manner of heating not only of the head of the rail but also of the web and base of the rail.

According to the method practiced under the present invention, a pair of rails are juxtaposed with their bases adjacent one another to form a pocket between the interior surfaces of opposed heads, webs and bases of the rails. The flame heads direct heat downwardly on the top surfaces of the heads of the rails to raise the surfaces above the critical temperature for steel. Deflectors deflect heat downwardly along the side surfaces of the heads of the rails and over the webs and bases of the rails as the rails are being moved past the flame heads. Accordingly,

a further object of the invention is the method of positioning a pair of rails with their bases abutted and deflecting heat from a flame head along the sides of the head of the rail, the web, and the base of the rail to heat these elements in order to eliminate distortion of the rail that necessitates a straightening operation.

Another object of the invention is to make more efficient utilization of the heat generated by the flame heads and to prevent the heat of the flame heads from escaping upwardly and damaging pipes and hoses leading to the flame head and to the quenching heads at a quenching station. More specifically, an object of the present invention is to create an air layer or curtain of cold air over the flame heads whereby heat escaping from the flame heads is forced downwardly along the rails to preheat the rails, and whereby this heat is prevented from its normal convection rise into the area of the pipes and hoses of the heat treating station.

Under the present invention and according .to one of its objects, rails are pulled through the surface treating United States Patent 0 3,497,403 Patented Feb. 24, 1970 "ice station by a novel wheeled, driving mechanism rather than having to be clamped to a stationary bed while a heating head is moved thereacross.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiment of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention.

In the drawings:

FIG. 1 is a front elevational view showing a rail being pulled through a surface-treating station by a driving mechanism;

FIG. 2 is a sectional view taken along the lines 2-2 of FIG. 1 and in the direction of the arrows showing side roller guides for urging a pair of rails to abut the edges of their respective inner base surfaces together;

FIG. 3 is an enlarged plan view of a mounting plate supporting the flame heads;

FIG. 4 is an enlarged sectional view showing the surface-treating station and deflector blocks deflecting the heat to the heads, webs and bases of a pair of rails;

FIG. 5 is an enlarged cross-sectional view of the flame head and quenching head;

FIG. 6 is a diagrammatic view showing an air pipe generating a layer or curtain of air forcing heated air downwardly to preheat the rails; and

FIG. 7 is an enlarged side elevational view showing an adjustable mounting for the flame and quenching head.

Referring to the drawings, and more particularly to FIGS. 1 and 4, one rail 10R of a pair of rails 10R and 10L is shown being pulled through a surface treating station 11 by a wheeled electromotive driving device 12. The heat treating station 11 is supported between a series of parallel and spaced horizontal support beams 14 which are in turn supported by a plurality of upstanding supporting legs 15. The supporting beams are I-shaped beams, and adjacent beams 14 are secured together by coupling plates 16 to form a long, rigid, longitudinal extending support. Extending between the beams 14 are series of spaced rollers 17 which support the rails 10R and 10L being towed thereacross by the driving device 12.

As digrammatically shown in FIG. 1, the rail 10 passes beneath a flame head 20 which heats the top surface 22 of the head 23 of the rail 10 to above the critical temperature for steel. Immediately after the top surface 22 of the rail head 23 moves past the flame head 20, the top surface 22 is air quenched from a quench head 25 to lower the temperature of the surface 22 to below the critical temperature for steel and as a result the top surface 22 becomes hardened. This operation is commonly referred to as a surface hardening operation.

The surface treating station 11, as shown in greater detail in FIG. 4, has a pair of rails 10R and 10L positioned with the interior side edge portions 26 of their respective bases 27 abutted against one another. The bases 27 of the rails are supported on a pair of adjacent rollers 17. Each of the rails 10R and 10L is heated by its respectively associated flame head 20R and 20L. The designation of the elements in the specification by an L or R suflix indicates that a pair of identical elements are being employed and all of the elements having an R suflix have in common the fact that they are functionally related to the rail 10R and vice versa.

Heretofore, only one rail at a time was heated, and as shown in FIG. 4, the present invention contemplates the simultaneous treating of two rails R and 10L positioned as shown in FIG. 4. When the rails 10R and 10L are positioned with their inner side edge portions 26 of their respective flanges 27 in engagement, an interior groove or pocket 30 is formed into which heated air from the flame heads R and 20L, respectively, moves downwardly across the side surfaces 32 of the heads 23 of the rails and into the pocket formed between the opposed webs 34 of the rails 10R and 10L respectively. In actual practice, it has been found that it is desirable to surface harden not only the top surface 22 of the rails, but also the side surfaces 32 of the heads 23. Since it is desired to surface harden the side surfaces 32- of the heads 23 in accordance with the present invention, suflicient heat is provided to raise the temperature of the sides 32 of the heads 23 above the critical temperature. Additionally, suflicient heat is generated to heat the webs 34 and bases 27 at the interior of the rails, though not to the critical temperature. This additional heating of the side 32 of the heads 23, bases 27 and webs 34 has been found to counteract excessive contracting and expanding occurring in the rails that caused the distortion heretofore experienced that necessitated a later straightening operation.

For the purpose of heating the outer side surfaces 32 of the heads of the rails 23, deflector blocks 37 are positioned adjacent the side surfaces 32 and are preferably canted at an oblique angle to the normal to direct some of the heat generated by the flame heads 20R and 20L into contact with the exterior or outer sides 32 of the head 23, web 24 and bases 27. The deflector blocks 37 are shown in FIG. 4 as being supported by angularly bent brackets 38 having an upper portion 39 hooked about their respective flame heads 20R and 20L and having a lower, hooked portion 40 in which are carried the deflector blocks 37.

The deflector blocks 37 must Withstand high temperatures and are, accordingly, formed of firebrick or other heat-resistant materials. The deflector blocks 37 are positioned relatively near the heads 23 of the rails and inclined at an angle suflicient to obtain the desired reflection. In practice, the outer edges of the deflector blocks 37 are usually placed about one inch from the closest portion of the outer surface 32 of a head 23 of a rail, and inclined at a small angle to the normal in order to direct the heated air downwardly along the exterior of a web 34 and against a base 27 of a rail 10R and 10L.

For the purpose of increasing the efficient utilization of the heat generated by the flame head 20, which heat has in the past been allowed to rise by convection and to be dissipated, a curtain or layer of cold air 41, FIG. 6, is directed over the hot air leaving the flame head 20. The cold air originates from an apertured air pipe 42 connected to a source of compressed air. The layer of air 41 forces the hot air downwardly along the heads 23, webs and bases 27 of the rails as they enter the heat treating station 11 to pre-heat these rails prior to their entry into the surface treating station 11.

The air curtain '41 performs an additional function in that it prevents the heat from rising or escaping upwardly of the flame head 20 in the vicinity of the flame head 20, thereby protecting the hoses, pipes and other elements located above the flame head 20, which elements would have to be insulated against the extreme heated air rising from the flame heads 20 if the air curtain 41 were not present.

The rails 10R and 10L are first quenched by air immediately after passing through the area of the flame head 20 and then are further reduced in temperature by a water quench which prevents residual heat from remaining within the thick heated head 23, which residually heated portion could cause distortion. As seen in FIG. 5, the flame head 20 has a top cover plate 45 from which projects a pipe 46 adapted to be connected to a line carrying a mixture of gas and oxygen. The top cover plate is water-tight in engagement with upstanding walls 47 and forms therewith a water chamber 48 through which is circulated cooling water from an inlet pipe 49 to an outlet pipe 50. The mixed gas and oxygen from the pipe 46 enter an enclosed primary chamber 51 and move through apertures 52 in a baffle plate 53 to a secondary chamber 54 prior to emerging from ports 55 formed in the bottom wall 56 of the flame head 20. The gas and oxygen mixture is, of course, burning exteriorly of the flame heads 20 and this burning furnishes the heat for the surface heating of the rails 10R and 10L.

The quench head 25 has a first air quenching chamber 59 for directing air through ports 60 and across the top surface 22 of a rail. Quench head 25 has a water chamber 62 for secondary quenching with water leaving through ports 63. As shown in FIG. 5, the quench head 25 is secured in close proximity to the flame head 20 by a nut and bolt type of fastener 64. Air enters through a pipe 65 into the air chamber 59 which is separated from the water chamber 62 by an enclosing wall 66. The water enters through a water pipe 67 and flows across the top of the wall 66 into the water chamber 62 whence it leaves through the ports 63.

To achieve the desired versatility of employing a single machine for varying sizes of rails, the flame head 20 and quench head 25 are adjustably supported at the treating station for lateral and vertical movement. More specifically, the turning of a hand wheel 70, FIG. 7, causes a supporting column 71 for the flame head 20 to move vertically; and the turning of a hand wheel 72 causes a horizontal and lateral movement of a column 71 and the flame head 20.

The hand wheels and 72) and the supporting column 71 for the flame head 20 are supported on a flat horizontal mounting plate 74 which is secured by a pair of forward supporting legs 75 and a rearward supporting leg 76 to the I-beams 14, FIG. 1.

The mounting plate 74 has a generally rectangularshaped opening 77, FIG. 3, through which opening extends each of the supporting columns 71 which are shown in FIG. 7 an being secured by a fitting 72' to the flame head 20.

In order to move a flame head 20 and quench head 25 vertically, a hand wheel 70 is turned to rotate a worm shaft 79 in a nut 80 to move the nut 88 vertically along the threaded shaft 79. The nut 80 is fastened to a bracket 81, which is clamped to the column 71 by fasteners 82. The end of the threaded shaft 79 is formed with an enlarged, circular, end portion 83 held within a race or groove 84 in a housing race 85. The enlarged end 83 is prevented by the housing race 85 from moving vertically, but is permitted to slide laterally in response to the turning of hand wheel 72.

To move a column 71 and its attached flame head 20 vertically, a hand wheel 70 is turned and as the threaded shaft 79 turns in the nut 80, the nut 80 moves vertically along with the bracket 81 to move the clamped column 71. The nut 80 is prevented from turning with the shaft 79 and is guided in its vertical movement by a guide rod 87 projecting through a guide bore 83 in the nut 80. Since the quench head 25 is attached to the flame head 20, both the flame head 20 and quench head 25 are moved simultaneously with a column 71 to position the flames, quenching air, and quenching water at a desired distance from the top surface 22 of a rail.

When it is desired to move a flame head 20 and a quench head 25 laterally, a hand wheel 72 is turned and rotates its shaft 90 to rotate a spur gear 91, secured to the shaft 90, to move the spur gear 91 along a horizontal and toothed rack 92. Shaft 90 is journaled in the housing support 94. The housing support 94 has a lower U- shaped portion 95 in slideable engagement with the side walls and bottom walls on the tooth rack bar 96 so that the housing 94 is confined to sliding transversely along the rack bar 96 as the spur gear 91 is rotated across the rack 92. For the purpose of horizontally moving a column 71 and an attached flame head 20, the housing support 94 has secured thereto a guide strap 97 which has an outer end portion 100, FIG. 7, apertured to permit the column 71 to slide vertically therein. The guide strap 97 guides the vertical movement of the column 71 at its lower portion and guides the column 71 for horizontal movement with the support housing 94 to which the guide strap 97 is secured.

In addition to rack bar 96, the opening 77 in the mounting plate is spanned by a'bracing bar 98 secured by nuts and bolts 99, which bar 98 serves to brace the mounting plate 74 at the opening 77.

In order to simplify the description, the various hose and pipe connections have not been shown but the inlets and outlet connections are described. Water is furnished from a water tank 100a carried on mounting plate 74. The mixed oxygen and gas mixture is supplied by mixing valves 101R and 101L, shown diagrammatically, on the mounting plate 74. More specifically, water from water tank 100a leaves one of the couplings 111 and is directed to couplings 105R and 105L that lead to water inlet pipes 49 entering the water chamber 48, FIG. 5, of flame head 20, and water exits the chamber 48 via pipe 50 and couplings 106R and L to a catch basin (not shown). The oxygen and gas mixture from mixing valves 101R and L goes through couplings 108R and 108L to pipe 46, FIG. 5, in the flame head 20, where it is burned to create the heat necessary for surface hardening. Water from coupling 111 of the water tank 100 is fed to couplings 110R and 110L leading to the quench heads 25. Couplings 112R and 112L receive air from outlet couplings 113R and 113L of an air chamber 114 and furnish the air for the air pipe 65 shown in FIG. 5 leading to the air chamber 59.

As best seen in FIGS. 3 and 7, the air tank 114 receives air from a line source 115 of air and delivers air through its outlet 116 to the perforated pipe 42, which blows air across the top of the flame head 20. The air is under considerable pressure and leaves the pipe 42 at sutficient velocity to drive the heated air rising above the flame head 20 forwardly and downwardly away from the hoses and pipes (not shown) which are situated above the flame head 20 and quench head 25. The air tank 114 has a gate valve 120 to control the flow of air through the pipe 42. At the opposite end of the pipe 42, a handle 121, FIG. 3, is provided for rotating the pipe 42 within a coupling 122 so that the direction of the air stream or air curtain can be varied to the degree necessary to obtain the forcing of the heated air downwardly and forwardly along the rails R and 10L. These rails are thus being subjected to a blast of heated air and are being pre-heated prior to entering the heat treating station 11.

The air tank 114 is supported at its rearward portion by a bracket 124 mounted on and extending outwardly of the supporting leg 76. The air tank 114 is supported at its forward portion by a bracket 125 secured to a leg 126, which leg is adapted to be attached to an I-beam 14.

Prior to entry of the rails into the surface treating station 11, the rails 10R and 10L are forced toward one another to abut their respective interior side edges 26 of their respective bases together by side roller guides 130 and 131, FIG. 2, which are positioned on opposite sides of the rails 10R and 10L.

The roller guides 130 and 131 are spaced at predetermined intervals along the length of the I-beams 14 on the entry or forward side of the surface treating station 11 to assure that the bases 27 of the rails 10R and 10L are abutted together when they enter the surface treating station 11. Side roller guides are not necessary on the exit side of the surface treating station 11 since the rails are straight and need not be constricted or attempted to be straightened.

Referring again to FIG. 2, the side roller guide has a roller 132 journalled in an upper supporting flange 133 and a lower supporting flange 134. The supporting flanges 133 and 134 are secured to an L-shaped bracket 135, secured to the I-beam 14. The opposite roller guide 131 has a spring biased roller which exerts a biasing force on the base 27 of the rail 10L tending to move the rail 10L laterally across its horizontal roller 17. This biasing force assures that the base 27 of the rail 10R is in engagement with its guiding roller 132 and that the side edges 26 of the respective bases 27 are in engagement.

The roller 140* has its ends journalled in opposed flanges 141 and 142 which are secured to a central and vertically extending support 143. Secured to the vertical support '143 is a piston-like, cylindrical extension 144 which extends into a cylinder-like collar 148 secured to a vertical leg 146 of an L-shaped bracket 145. The L-shaped bracket is secured to the I-beam 14. The collar 148 receives the cylindrical extension 144 of the support 143 and guides the extension 144 for reciprocal movement like a piston in a cylinder. The cylindrical collar 148 has a pair of opposed studs 149 which are welded to its outer peripheral surface. A spring plate 150 is bolted to the studs 149. Secured to the spring plate 150 is a cylindrical sleeve 151 in which is disposed a compressed, coil spring 152. Spring 152 bears against the spring plate 150 and against the piston-like cylindrical extension 144 to urge the cylindrical extension 144, the support 143, and the roller 140 toward the opposite roller guide 130. Thus, the spring 152 biases the roller '140 against the base 127 of the rail 10L. In this manner, the biasing roller guides 130 and 131 assure that the bases 27 of the rails 10R and 10L are abutted at their respective interior portions 26 of their bases 27.

To attach the rails 10R and 10L to a pull bar 161 of the electromotive drive mechanism 12, the rails 10R and 10L are joined together by a pin 160, FIG. 1. The electromotive mechanism 12 has an electric motor and gear reducing drive under a cover 162 which cause rotation of a spur gear 163 by means of an interconnecting chain (not shown), the spur gear 163 traveling along a stationary tooth rack 164. The tooth rack 164 is supported by the spaced axles 166, FIG. 4, and as shown in FIG. 4, is medially disposed between the pairs of opposed rollers 17.

As apparent from FIG. 1, the electromotive drive mechanism 12 is provided with wheels 168 adapted to roll over spaced tracks 169. The tracks 169 are attached to upstanding legs 170, FIG. 2, of L-shaped brackets 171. Thus, as the spur gear 163 is turned by the electric motor and drive gearing arrangement, the spur gear 162 moves along the rack 164 and the wheels 168 roll along the opposed tracks 169. In order to assure that the spur gear 163 is properly engaged with the rack 164, the spur gear 163 is mounted on the end of a vertically movable worm shaft which is threaded through a nut 176 of an arm 177 on the drive mechanism 12.

From the foregoing, it is believed to be apparent that by juxtapositioning the rails with their bases abutted together and applying heat in the above-described manner that two rails can be surface hardened simultaneously. Also, by deflecting heat to Webs and bases of a pair of rails at the time of heating the top surface of the head of the rail above critical temperature, a pair of rails can be surface-hardened by a later quenching without the usual accompanying distortion, necessitating a straightening operation on the rails.

Also, it should be apparent that the present device also employs a novel air curtain or layer to cause upwardly escaping heated air to be forced downwardly to pre-heat the rails and prevent the heated air from damaging the hose and pipe connections to the flame and quench heads.

Hence, while we have illustrated and described preferred embodiments of the present invention, it is to be understood that these are capable of variation and modification.

We claim:

1. A method of flame heating to simultaneously surface harden the heads of a pair of steel railroad rails, said method comprising the steps of positioning the pair of rails with the respective interior portions of their bases abutting against each other; moving the rails beneath flame head means in a heating station for heating the top surfaces of the heads of the rails to above the critical temperature for hardening steel while simultaneously heating the webs and bases to a temperature below said critical temperature by deflecting heat downwardly by means of deflector block means canted at an oblique angle to the normal of the web sections and positioned adjacent the exterior side surfaces of the rails in order to direct some of the heat generated by the flame head means downwardly along the exterior or outer sides of thehead, web and base portions of the rails; quenching the heated surfaces of said heads of the rails to lower the temperature thereof 8 below said critical temperature; and quenching the webs and bases to lower their temperatures.

2. The method of surface hardening the heads of a pair of steel railroad rails as set forth in claim 5, with the additional step of blowing the heat rising from the heating station forwardly and downwardly across the rails entering the heating station to pre-heat the rails.

References Cited UNITED STATES PATENTS 1,008,674 11/1911 Russell 148-446 2,882,191 4/1959 Van Swaal 148146 3,266,956 8/1966 Bennewitz et al. 148--146 X 3,275,481 9/ 1967 Adams 148151 X CHARLES N. LOVELL, Primary Examiner US. Cl. X.R.

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