US2573308A - End hardening of rails - Google Patents

Description

Oct. 30, 1951 A. c. CHAMBERLIN ETAL 2,

END HARDENING OF RAILS Filed April 2, 1948 s Sheets-Sheet 1 Wardgns;

Oct. 30, 1951 A. c. CHAMBERLIN ETAL 2,573,308

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Oct. 30, 1951 A. c. cHZ'MBERuN' ETAL 2,573,308

END HARDENING OF RAILS Filed April 2, 1948 8 SheetsSheet 5 Inventors [ZasselZ/Il /flare llzmnfi 1951 A. c. CHAMBERLIN ETAL 2,573,308

END HAfiDENING OF RAILS I 8 Sheet-Sheet 6 Filed April 2, 1948 NNN ' 00811501 6 fiwscl ll Ie 111m 6*. (Yea ll? 1951 A. c. CHAMBERLIN EI'AL END HARDENING 0F RAILS 8 Sheets-Sheet '7 Filed April 2, 1948 ZfuSSeZZMII Z c. CHAMBERLIIN ETAL 2,573,308

Oct. 30, 1951 END HARDENING 0F RAILS Filed April 2; 1948 8 Sheets-Sheet 8 la erla'w;

- Muss-00M Ian/616W Patented Oct. 30, 1951 Alan 0. 'Chamberlin, Bethlehem, and Russell M. Weigle, Steelton, Pa., assignors to Bethlehem Steel Company, a corporation of Pennsylvania Original application April 9, 1947, Serial'No.

740,344. Divided and this application 1948, Serial No. 18,518

This invention relates generally to a method for heat treating rails and more particularly to amethod for. heat treating the ends of the tread surfaces of rails, and is a division of our copending application, Serial No. 740,344, filed April 9, 1947, now Patent No. 2,519,354, for End Hardening of Rails.

7 During service in railway tracks, the ends of the rail tread surfaces are subjected to a greater amount of wear than the remainder of the tread surfaces due to the impact of the rolling stock in passing over the joint from one end of one rail onto the end of an adjacent rail.

. We are aware that the tread surfaces at the ends of rails have been hardened by locally heating only the portion to be hardened to a temperature at or above the critical range by means of a high temperature heating flame or electrically by induction or by passing an electric are over the surface portion to be hardened and then quenching the heated portion by a liquid or air quench.

This is usually accomplished by heating the tread portion at each end of the rail separately to a high temperature in a single operation and then quenchin each end separately.

Among such methods is that commonly known as flame hardening wherein the upper surface of the rail end is rapidly heated in one operation by means of an oxyacetylene flame or the like and then quenched in air or water. This treatment produces ahard case upon the upper surface of the rail without affecting the toughness and shock-resisting ability of the core. The rapid heating of a cold rail followed by the quenching of a small area of the rail head tends to promote cracking of the treated portion. It is also extremely difficult to produce uniform results by said method. Heating by means of the oxyacetylene torch is an extremely rapid operation and. accordingly small variations in the length of heating will produce appreciable variations in the depth of penetration of the heat, with corresponding variations in the depth of the finished case. The quenchin operation is likewise difficult since small variations in the duration of the quench operation will produce appreciable variations in the hardness of the "case. Accordingly, uniformity of results in flame hardening as above described can be obtained only with difiiculty.

We have found that by slowly preheating the end of the cold rail and then subjecting-it to a .high flame prior to locally hardening the heated surface of the rail head lessens the tendency 2 Claims. (Cl. 148 -21.56)

April 2,

of the rail to crack as a result of the local application of the intense heat of thetorch fol lowed by the quenching of the heated portion.

The end tread surfaces of rails have been hardened by first heating the rails in a furnace and when discharged therefrom the endtread portions have been quenched.

Rail ends have also been surface hardened after being laid in the track but such a procedure usually necessitates the use of a wheeled carriage adapted to roll along the track, and having a considerable amount of apparatus .mounted thereon for accomplishing the heating. and quenching operation. Much time is consumed in rolling the carriage up and down the track, in adjusting the apparatus for each particular joint, and in removing the apparatus from the track upon the approach and passage of a train or other equipment using the track.

One object of this invention relates to advance ing a plurality of rails laterally in a step by step movement and subjecting the end tread surface of each rail to a plurality of burners to slowly raise the temperature of the end tread portion of each end of the rails to a point above the critical range, then quenching the heated ends of each rail to a point below the critical range .and then advancing the rails to a cooling bed for air cooling.

Another object of this inventionrelates to advancing a plurality of rails laterally intermittently in a step by step movement and subjecting the end tread surface of each rail to a plurality of preheater burners, then to a high heat burner where the temperature is raised to a point above the critical range, then advancing the rails and subjecting the heated portion at the end of each rail to an air blast to quench -it below the critical range and then advancing the rails to a cooling bed for air cooling.

Another object of the invention relates .to ad- :vancing a plurality of rails laterally intermittently in a .step by step movement at substantially a minute and one-half intervals and sub- --jecting the end tread surface of each rail to a plurality of preheater burners to heat the end tread portions to a temperature of substantially 1000 F., then to a high heat burner where the :temperature is raised to at least 1450 F., then subjecting the heated portion of each rail to an air blast to quench it to 900 F. and finally ade -.vancing the rails to a cooling bed for air cooling. Another. objectv of this invention relates to 'initially taking cold rails advancing a plurality filofthe rails laterally. intermittently in a step by each rail to an air blast to quench the ends of the rails to substantially 900 F. and finally ad-,

vancing the rails to a cooling bed for air coolmg.

The usual rail steel normally requires only the application of an air quench in order to produce the desired hardness and this invention will be explained with reference to air quenching, but it will be understood that liquid cooling might be employed without departing from the spirit of our invention.

Some rail steel have a critical temperature of about 1350 F., but this may vary somewhat with different steels and steel alloys. We have found that 1450" F. is desirable for our purpose, although in some cases it may be desirable to raise the temperature as high as 1550 F. before quenching for hardening and we do not limit the heating to 1450 F., as it may be slightly greater or less without departing from the spirit of our invention.

With the foregoing and other purposes in view which will become more fully apparent as the nature of the invention is more fully described, this invention consists in the novel features which will be hereinafter more fully described and illustrated in the accompanying drawings and defined in the appended claims.

Referring now to the eight sheets of drawings forming a part of this specification in which like characters of reference indicate like parts:

Figure 1 is a perspective view of an apparatus for heat treating one end of a plurality of rails embodying our invention.

Fig. 2 is a perspective view of an apparatus similar to Fig. l for simultaneously heat treating the opposite ends of the same plurality of rails.

Fig. 3 is a top plan view of the general arrangement of the end hardening equipment shown in Fig. 2.

Fig. 4 is a vertical transverse section taken on the line 44 of Fig. 3, and showing the relative position of the shock absorbing device in dotted lines.

Fig. 5 is a detail view drawn on a larger scale of one of the high heat "Selas burners and the general arrangement of support therefor showing parts in section to more clearly show the construction.

Fig. 6 is a detail view drawn on a larger scale of one of the air quench devices and the general arrangement of the air quench support with parts in section.

Fig. '7 is a detail section taken on the line 1-4 of Fig. 8, showing the general arrangement of one of the shock absorbers in the act of turning one of the rails after they have been advanced down a skid from the drilling machines to the reciprocating slide bar having dogs pivoted thereto.

Fig. 8 is a top plan view of a portion of the shock absorber shown in Fig. '7.

Fig. 9 is a top plan view of one of the shock absorbers showing its connection to one of the slides carrying the dogs.

Fig. 10 is a section through one of the slides carrying the dogs taken on the line I 0I0 of Fig. 11 showing how the pivoted dogs pass under the rails during the return stroke of the slide,

4 and Fig. 11 is a transverse section through one of the slides taken on the line IIII of Fig. 10.

In the manufacture of rails, after the rolling operation the rails are hot-sawed into lengths, they are then cooled on a cooling bed. After the rails are cooled on the cooling bed both ends of the rails are treated simultaneously by duplicate machines.

The rails are first advanced sidewise to a pair of milling machines for removing the burr from the ends of the rails caused by hot sawing, then advanced to drilling machines and holes drilled in the web of the rails adjacent to each end. These operations are well known in this art.

Referring now to the characters of reference on the drawings, the numeral [indicates the skid upon which the rails 2 are received after the drilling operation and upon which they are advanced downwardly by gravity to a pair of shock-absorbing devices 3 which feed the rails to the ap-.- paratus for heat treating. Both ends of the rails are heat treated simultaneously by duplicate apparatus and a detailed description of one will apply to both. The shock absorbing devices 3 are disposed between the heat treating apparatus and adjacent thereto as indicated in Fig. 9, the construction of which is more clearly shown in Figures 7 and 8. The shock absorbing devices 3 are each mounted in a frame 4, adapted to form a part of the skid I, which is supported at an intermediate point near one end by means of a pin 5 on a bearing 6 and at the other end by means of a post 1 which is pivoted at the upper end to frame 4 by means of a pin 8 and pivoted at the lower end to bracket 9 as at I0.

The shock absorbing devices are each provided with a rocking lever I I having a hub I2 at an intermediate point for receiving a shaft l3 which has its ends supported in the frame 4. Spaced side plates I4 are attached at their upper ends by means of shafts I5 and I6 for supporting the operating mechanism for the rocking lever II.

The rocking lever II is resiliently held at one end which is attached thereto by means of a pin H to the clevis end [B of a bolt I9. The shank 20 of the bolt i9 is provided near its upper end with a Washer 2| having trunnion projections 22 pivoted at 23 in the spaced side plates I4. The lower end of the shank 20 is provided with a washer 24 and interposed between the washers 2I and 24 is a helical spring 25. The lower end of the bolt is threaded to receive nuts 26 to give greater or less tension to the spring 25.

The opposite end of the rocking lever I I to that resiliently held is provided with an abutment shoulder 21 adapted to engage and support the base of the rails 2 during the manipulation of them through an arc of substantially 90 thereby turning the webs of the rails from a horizontal to a vertical position. Pivctally attached to the rocking lever l I as at 28 adjacent to the abutment shoulder 2'! is a clevis member 29 adj ustably connected as at 38 to a piston rod 3I working in a fluid pressure cylinder 32 pivoted at its lower end by means of a pin 33 to the lower ends of the spaced side plates l4. This fluid pressure cylinder acts as a dash pot and is supplied with liquid such as oil or the like from a reservoir or tank 34 which is. connected to the upper end of and is returned to the reservoir and the top end of the cylinder.

A shaft 39 is also mounted in the frame 4 of each of the shock absorbers 3 adjacent to the shaft I3 and has mounted thereon, at one end a cam plate 40 to which the bifurcated end H of a connecting rod 42 is pivoted as at 43. The opposite end of this connecting rod 42 is also bifurcated and is pivoted by means of a pin 44 to a crank arm 45 which is mounted at an intermediate point on a rock shaft 45 which is mounted in bearings 41.. As it is sometimes necessary to adjust the length of the connecting rod 42 the central portion is provided with a sleeve nut 48.

A crank arm 49 is keyed to each end of the rock shaft 46 each having their outer ends pivoted as at 50 to one end of a pitman rod which have their opposite ends connected to one of the slide bars 52 which are reciprocated in slideways 53 by means of pressure cylinder 54, and form means for conveying the rails intermittently. The slideways 53 are formed of two rails spaced apart forming a table for receiving the rails between which the slide bar 52 is adapted to reciprocate and are mounted by means of brackets 55 on a truck frame 56 provided with rollers 5! engaging rails 58 mounted on a base frame 59 whereby the truck may be adjusted for different lengths of rails. The reciprocating slide bars 52 have side walls 60 connected by vertical transversely extending ribs BI and a bottom wall 52 with openings 63 therein each adapted to normally receive the weighted end 64 of a dog 55 which is pivoted on a shaft 65 supported by the side walls 80. Each dog is provided with a toe 67 adapted to engage during the forward stroke of the slide bar 52 the base flanges of the rails under heat treatment and to advance all the said rails one step and on the return movement of the slide bar 52 to rotate and slide under the base flanges of the rails 2 as indicated in Fig. 10.

The fluid pressure cylinder 54 for actuating the slide bar is mounted on the truck frame 55- and has the outer end of the piston rod 68 working therein pivotally connected as at 69 to an ear I0 extending downwardly from the bottom wall 52 of the slide bar 52. As the toe 61 of the dogs 65 have to clear the base flanges of the rails 2 under heat treatment, the reciprocating stroke of the slide bar has to be slightly greater than the step by step movement of the rails 2 treated so that at the end of the return stroke of the slide bar the toe 51 of the dogs will be spaced from the edges of the base flanges of the rails 2 as clearly shown in Figs. 1 and 2. As it is necessary to limit the forward stroke of the slide bar a stop II is provided on the truck frame 56 adapted to engage the shoulder 'I2 on the inner face of the rear end of the slide bar.

It is sometimes necessary to release thetoes 87 of the dogs 65 from the base flanges of the rails or to back the slide bars 52 slightly and for this purpose a push type solenoid I3 is mounted on the bottom of the rear end of the said slide bar with its magnet 14 pivotally connected by means of a link 15 to the Weighted end 64 of the rear dog 65. I

The rails 2 are advanced sidewise in a step by step movement at minute and one half intervals during each reciprocation of the slide bars 52 and both ends of the rails are heat treated simultaneously. For illustration the ends of six rails are shown being treated but this number could be varied without departing from the spirit of our invention. As shown the rails are first advanced to four Selas preheater burners 16 each connected to a branch pipe 11 of a main fuel supply pipe 18 which has adjustable supports 19. The branch pipes H are each provided with a valve for controlling the supply of gas for each of the Selas preheater burners. During the preheating operation the temperature of the top end tread surface of the rails are slowly raised to substantially 1000" F. The forward rail is then advanced to the high heat Selas" burner 8| where the temperature at the ends of the rail are raised to substantially 1450 F. The rail is then advanced to the air nozzles 82 for the air quench. After it is air quenched the temperature at the ends of the rails is reduced to substantially 900 F., after which it is advanced to a skid way 83 where the rail is deposited on a cooling bed (not shown) for final air cooling. As shown in Fig. 5, the high heat Selas burner 8| is adjustably mounted in a support 84 and is provided with a gas supply pipe 85 and is water cooled having inlet and outlet pipes 85 and 8'! respectively; The outlet pipe 81 discharges into an overflow pipe 88.

The support 84 has its lower bearing surface 89 slidably and resiliently mounted in a base plate 90 having at its outer end an upwardly extending flange 9I for receiving an adjustable bolt 92 which is threaded as at 93 at its outer end to receive nuts 94.

The base portion of the support 84 is recessed as at 95 and is provided at an intermediate point with a downwardly extending flange 95 which is perforated at 91 for the shank of the headed end of the bolt 92 to pass through. A spring 98 is.

mounted on the bolt 92 interposed between the flanges 9| and 96 having its ends engaging washers 99 and I00. An adjustable gage arm IOI is secured to the lowerv portion of the base portion of the support 84 by means of set bolts I02 and is provided with a cylindrical threaded portion I03 at one end extending through a hole I04 in the flange 96 and is clamped thereto for adjustment by means of nuts I05. The opposite end of the gage arm IOI is provided with a rotating gage wheel I06 for engaging the ends of the rails 2. The gage wheel I06 is attached to the end of the gage arm IOI by means of a bolt I0? and has an asbestos board I80 of disk shaped mounted thereon to protect it from the flame of the high heat burner.

The support I09 for the air nozzle 82 shown in detail in Fig. 6 is similar to that for the high heat Selas burner '8I shown in Fig. 5.

The air nozzle 82 is slidably mounted in a support I09 and is provided with an air supply pipe IIO controlled by a solenoid operated valve III. The support I09 has its lower bearing surface I I2 slidably and resiliently mounted in a base plate II3 having at its upper end an upwardly extending flange II4 for receiving an adjustable bolt II5 which is threaded as at H6 .at its outer end to receive nuts III. The base portion of the support I09 is recessed as at H8 and is provided at an intermediate oint with a downwardly extending flange II9 which is perforated at I20 for the shank of the headed end of the bolt II5 to pass through. A spring I2I is mounted on the bolt II5 interposed between flanges H4 and H9 having its end engaging washers I22 and I23. An adjustable gage arm I24 is secured to the lower portion of the base portion of the support I09 by means of set bolts I25 and is provided with a cylindrical threaded portion I25 at one end extending through a hole I21 in the flange I I9 and is clamped thereto for adjustment by means of the nuts I28. The opposite end of the gage arm I24 is provided with a rotating gage wheel I29 for engaging the ends of the rails 2. The gage wheel 129 is attached to the ends of the gage arm 124 by means of a bolt I30 and has an asbestos board 13! of disk shape mounted thereon to protect it from the heat of the end of the rail.

The operation of our device is as follows: Assuming that the holes in the rails 2 have been drilled and the rails then delivered to the skid l where they are advanced by gravity to the shock absorbing devices 3. Referring to Fig. 4, a rail has just been turned 90 by the cam plate 40 during the forward stroke of the piston rod 68 working in the fluid pressure cylinder 54 and the pivotal point 50 in the outer end of the crank arm 49 has traveled in the arc of a circleas indicated at 132, while the pivotal pin 44 of the crank arm 45 for actuating the shock absorber has simultaneously traveled in the arc of a circle as indicated at I33. In this figure the abutment shoulder 27 of the rocking lever H has been depressed below the top of the slide way 53 by the movement of the cam plate 49 and fluid pressure has just been admitted to the front end of the cylinder 54 to reciprocate the piston rod 68 in its return movement. When the abutment shoulder 21 of the rocking lever l i is forced .downward the piston rod 3| is forced downwardly. in the fluid pressure cylinder 32 and the spring 25.0n the bolt I9 is compressed between the washers 2i and 24. As indicated in Fig. 4 the toes 61 of the dogs 65 have just been advanced into engagement with the edges of the-base flanges of the rails 2. At the end of the backward stroke of the piston rod 68 all the rails will be advanced from one heat treating position to the next. To insure the exact space movement for each step the slide bar is provided with a shoulder.'l2 for engaging a stop H on the truck frame at the end of the forward stroke of the slide bar and the cam plate 40 is rotated until the end engaging the rail during the turning operation is below the top surface of the skid I, while the abutment shoulder will be raised by the action of the spring 25 on the bolt l9 into the position indicated in Figs. 7 and 8.

When the cam-plate is in the position indicated in dotted lines in Fig. 4 the rails 2 on the skid l are prevented from further downward movement by engaging the edge of the cam plate 40 as indicated in Figs. 4 and 7, but when the cam plate is rotated so it is entirely below the skid l the rails are free to slide downwardly until they engage a stop I34 where the forward rail is held until the slide is moved backward again thereby first raising the forward rail into position indicated in Fig. 7 with its base flanges engaging the abutment shoulder. As the cam plate 48 rotates the rail is rotated 90 to the position indicated in Fig. 4. The operation above described is repeated at minute and one half intervals for each step by step movement of the rails during the heat treating operation. After leaving the Selas preheater burner ends of the tread of each rail the temperature is raised to 1000" F. The high heat Selas burner then raises the temperature to substantially 1450 F. and the air quench of the nozzles 82 then reduces the temperature to substantially 900 F. The rails are then conveyed to a cooling bed and air cooled.

Although we have described and illustrated our 8 invention in considerable detail, we do not wish to be limited to the exact and specific details thereof, as shown and described, but may use such modifications in substitution for, or equivalents thereof, as are embraced within the scope of our invention, or as are pointed out in the claims.

Having described our invention, what we claim as new and desire to secure by Letters Patent is:

1. In a method of heat treating the ends of rails, the steps of disposing the rails in substantial parallelism with the heads of the rails equally spaced, advancing the rails in unison in a direction transverse of the lengths of the rails, disposing a plurality of preheating flames and a final heating flame of higher temperature equally spaced along the path of the ends of the rails whereby the advance of the rails bring them successively into heat interchanging relationship with such flames, intermittently interrupting the advance of the rails for a time interval when the rail end portions are in such heat interchanging relationship with the flames whereby the rail end portion of each rail is successively preheated by such preheating flames to bring a substantial mass of the metal of the end portion of each rail to a high temperature but below the critical range and the tread portion of each rail is raised above the critical range by said final heating, high temperature flame, and quenching the tread portion of each rail.

2. In a method of heat treating the ends of rails, the steps of disposing the rails in substantial parallelism with the heads of the rails equally spaced, disposing a plurality of preheating flames and a final flame of higher temperature equally spaced along a line which continues the line of the ends of the rails, effecting a relative movement between the rails and said flames in a direction transverse of the lengths of the rails whereby the rail ends are successively put into heat interchanging relationship with said flames, intermittently interrupting said relative movement when the end portions are in such heat interchanging relationship with said flames whereby the rail end portion of each rail is successively preheated by such preheating flames to bring a substantial mass of the metal of the end portion of each rail to a high temperature but below the critical range and the tread portion of each rail is raised above the critical range by said final heating higher temperature flame, and quenching the tread portion of each rail.

' ALAN C. CHAMBERLIN.

RUSSELL M. WEIGLE.

- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 694,838 Coyan Mar. 4, 1902 2,032,738 Cramer et al Mar. 3, 1936 2,070,889 Frickey et al Feb. 16, 1937 2,129,670 Brunner Sept. 13, 1938 2,254,307 Mott Sept. 2, 1941 OTHER REFERENCES The Making, Shaping and Treating of Steel. Page 760. Published by Carnegie-Ill. Steel Corp. 5th ed. 1940.

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