US2198808A

US2198808A - Method of and apparatus for hardening rail ends

Info

Publication number: US2198808A
Application number: US101358A
Authority: US
Inventors: Cecil V Eskridge
Original assignee: Linde Air Products Co
Current assignee: Linde Air Products Co
Priority date: 1936-09-18
Filing date: 1936-09-18
Publication date: 1940-04-30
Anticipated expiration: 1957-04-30
Also published as: GB501340A; FR825906A

Description

April 30, 1940.

c. v. ES'KRIDGE METHOD OF AND APPARATUS FOR HARDENING RAIL ENDS Filed Sept. 18, 1936 2 Sheets-Sheet 1 INVENTOR CECIL V. ESKP/DGE ATTRE April 30, 1940;" c. v. ESKRIDGE 2,198,808

- METHOD (5F AND APPARATUS FOR HARDENING RAIL EN'DS FiledSejpt/lS, 1936 I 2 Sheets-Sheet 2 INVENTOR CECIL l/. ESKR/DGE ATTORNEY Patented Apr. 30, 1940 UNITED STATES METHODOF AND APPARATUS FOR mum'- PATENT OFFICE ENING RAIL ENDS Cecilv. Esl rridge, Chicago, 111., assignor to The Linde Air Products Company, a corporatipn of Ohio This invention relates to the heat treatment of rails and particularly to a novel method of and apparatus for hardening the tread'surfaces of rails. r

When rails are in service, the tread surfaces adjacent the ends of the rails at joints in the track become battered to a lower level than the rest of the tread surfaces of the rails. .This is due to the fact that at the ends of the rails there is no support against end flow of rail surface metal, and consequently the rate at which the tread surfaces become battered is greatest at the rail ends. Heretofore, it has been the practice to harden a substantially rectangular area of the tread surface adjacent the rail lend by heat treatment so as to retard the rate of batter. The desired uniform hardness has usually been obtained by applying a localized I high temperature heating medium, e. g. an oxyo acetyle'ne flame or an electric arc, to the area Q5 with a suitable quenching medium, such as air or water. When a blast of air of sheet-like form is employedas the quenching medium, and moved relatively to the work, a low pressure area is created at the rear side of such sheet which tends to deflect the heating flame envelope, or the heated air adjacent thereto, upon the treated section in the rear of the air blast. This flame envelope and the conducted heat from the rail will tend to heat and temper the hardened portion, destroying-its uniformity or preventing the desired hardness from being obtained.

. Moreover, it has also been found that when a rectangular area of the tread surface is hardened to a uniform depth and degree in this manner, there will be an abrupt transition between the hardened heat treated tread surface ends of rails which will not be subject to the 1 above mentioned disadvantages. Another object is to provide such an improved method, and

apparatus for practicing the method, which will' produce an effective hardened tread surface'capable of resisting batter. Other and more specific objects are: To provide a method and apparatus for quenching the highly heated portion of the rail which will be adapted to produce a hardened area having maximum hardness at the end of the rail and gradually decreasing hardness toward theuntreated tread surface'of the rail so as to avoid abrupt transi tion between treated and untreated portions; to provide such a method and apparatus which will prevent reheating of the treated surface due to the low pressure zone in the rear of the air blast; and to provide a baflle for separating the source of high temperature heat from the quenching medium.

The above and other objects and novel features: of the invention willbecome apparent from the following description, having reference to the accompanying drawings, in which:

Fig. 1 is a side elevational view of one form of apparatus for hardening the tread surface areas of rail ends and embodying the principles of the present invention;

Figs. 2and 3 are, respectively, fragmentary left and right hand end elevational views of portions of the apparatus shown in Fig. 1;

Fig. 4 is a horizontal sectional view, partially diagrammatic, taken along the line 44 of Fig. 3, and showing the construction of shells or chambers for the quenching air blasts; V Fig. 5 is a view similar to Fig. 4 showing a modified form of air blast shell;

Fig. 6 is a fragmentary ,end. elevational view of a modified form of apparatus embodying the principles of the present invention, and adapted to be moved longitudinally over the tread surface of a rail; and

Fig. '7 is a horizontal sectional view taken along the line 1-1 of Fig. 6.

In accordance with the principles of this invention, the tread surfaces of rails, or the portions thereof to be treated, are rapidly heated to an elevated temperature in any suitable manner. For example, a multiflame oxy-acetylene blowpipe may be employed, which has a sumcient number of heating tips to heat uniformly a desired small area of the tread surface adjacent the end of the rail. Such a source of high temperature heat may be moved progressively over the surface portion which is to be hardened to heat said portion to a temperature above the critical point for the particular steel employed. Upon being heated. to the desired elevated temperature in this manner, a suitable quenching medium is applied to cool the metal 2 i and thereby produce the desired hardness. This cooling may be effected by means. of a 'system c of air'quenches which are preferably applied to the heated tread surface portion in the form of sheet-like blasts. One of these blasts-follows directly behind the heating medium and may be substantially coextensive with the width or length of .the heated area, depending upon behind such first air blast and thereby tends to.

heat and temper the hardened portion. Accordingly, there is included in the system of air blasts a second sheet ofair under pressure which I ing blast of air prevents reheating after harden-' ing and further assists the first sheet of air in cooling the heated path. If desired, the heat- 1 ing means may be definitely separated from ,'0f the treatedsection-may be progressively re- 'duced toa point where it will merge with the the quenching means by means ofa water cooled bailie. It will be apparent that in the above out= lined method of heat treatment, the heating medium and the quenching air blastsmay be moved either longitudinally or transversely of the rail-being treated. The former procedure may be applied to the heat treatment of rails laid in track or to rails in the mill before being laid intrack; while the latter procedure is particularly adapted to be carried out in the treatment of rails in the steel mills.

When the heating medium and the air blasts are moved transversely of the rail, an economy in gas consumption and labor may be effected by placing a plurality of rails parallel to each other -so that they may all be'hardened in a single pass as the heating medium and quenching means are moved progressively from one rail to the next. Furthermore, variations in the hardness of the treated portion of the tread sur a face may be more readily effected with the transverse procedure. Should it be desired to produce a greater hardness at the extreme end of the rail, a greater amounto'f air may be readily supplied at this point to effect a more rapid quenching normal grain structure of the -unt reated tread surface of the rail.

Referring to Figs.- 1. 2, and, 3, wherein is shown one form of apparatus for hardening a plurality of rail ends placed side by side in accordance with the procedureoutlined above, it wiJl be seen that a source of high temperature heat H and a quenching device Q may be progressively moved over the end portions of the tread surfaces of a plurality of rails R by means of a suitable travel- 4mg machine M. The machine M is .employed plication of 'J. H. Bucknam and A. J. Miller,

Serial N .4'.7.0;'fl1d January 12, 1935. 'Such a machine comprises a motor driven carriage i0 which is adapted to be driven along the surface q e h of'thework, the floor, or atrack l I. A cross arm i2 is mounted on the upper side of the carriage l0 and has secured to one end thereof a vertically disposed guide member l3 which receives a slide M. The slide I 4 is adapted to be moved up and down in the guide l3 by meansof a handle l5 and has a clamping sleeve i6 adjustably connected thereto. A- tubular supporting member I], which is part of a main supporting frame F for the heating and quenching means, is removably mounted in the clamping-sleeve i6 so that as the machine M travels along the track I I said heating and quenching means may be progressively moved from one rail end to the next. The speed of the machine M is adjusted so that the end portions of the rail tread surfaces will be.

heated to the desired elevated temperature as the heating medium H moves progressively over such surfaces. J

The supporting frame F comprises, in addition to the tubular member II, a horizontally disposed angle member it which is hinged at 19" to said v tubular member I'L The opposite end of the member "is maintained in a horizontal position by means of asupporting leg 20 which is bifurcated at its lower extremity so as to receive a wheel 2i that is adapted to'ride along over the tread surfaces 'ofthe rails R or on a'suitable plate or track 22. At its upper end the leg 20 is adjustably secured by means of a set screw 23 (Fig. 2) in an opening 24 provided in a bar 25.

This bar is rectangular in cross section -and. is.

received in a similarly shaped opening 26 provided in the vertical flange of the angle-member l8 and is removably held therein by means of a set screw-21. With'such a construction, the leg 20 may be adjusted both horizontally and vertically so that' it will not be in the way of other parts of the apparatus.

Heating of the end portions of the rail tread surfaces is accomplished by means of the source.

of high temperature heat H which, asshown, may comprise a suitable oxyacetylene blowpipe having a head 30 provided with a plurality of heating nozzles or tips 3i that are adapted to be connected with a source of gaseous fuel so as to provide high temperature heating flames. The distribution and number of these tips 3! in the head 30- may be varied and positioned so as to give a uniform distribution of heat over the area of the tread surfacewhich is to be treated. A

casing 32 is attached to the head 30 and provides a convenient housing for'the necessary gas sup. ply conduits leading to the tips 3!. Water for cooling the blowpipe head'30 may be supplied from 'any convenient source through water connections or conduits 33 which are shown entering the upper end ofthe casing 32. The casin 32 of to the rail ends and is consequentlyadapted to be moved progressively from one rail to the next as the supporting frame F is so moved by means of the travelling machine M. It will be noted that the tips 3|, may be spaced at any suitable distance from the tread I surfaces of the rails either by adjustment of the casing and bracket 34, or by adjustment of" the tubular member 11.

- and the leg 20. As the end portions of the rail tread surfaces are heated progressively by the blowpipe travelling across' the surfaces thereof, they are immediately quenched by the quenching means Q which is arranged to follow directly behind .the

outer end thereof so that greater quantities of source of high temperature heat. .Air is preferably employed as the quenching medium and such quenching air is applied to the heated tread surface of the rail by means of a box-like air shell or chamber 35 which may be constructed of any suitable material such as thin sheet metal. Compressed air is supplied to the chamber 35 from any convenient source of supply through a supply conduit 36 entering the upper portion thereof. The bottom side of the air shell 35 is preferably positioned horizontally or parallel to the tread surface of the rail and is provided with a slot. 31 through which the air may issue and be directed upon the heated rail surface. This slot may be coextensive with the length of the heated area, though preferably said slot may extend from the extreme end of the rail to a point somewhat short of the length of the heated portion, since the unheated steel in the rail adjacent the heated portion will also have a quenching effect. Should it be desired to produce a greater hardness at the extreme end of the rail, the slot 31 may be provided with a widened portion 38 at the surface more quickly and effect a greater hardnesstherein.

' Behind the air shell 35, or to the left thereof as shown in Fig. 3, there is provided a secondary air shell or chamber 39. which is supplied with compressed air through a supply conduit 40 and is similar in shape and construction to the air shell 35, being provided with a slot 4| in the bottom side thereof. This second air chamber, however, is arranged perpendicularly to the first air shell 35-and is attached thereto by means of brackets 42 so that theblast from the slot 4| will be perpendicular to the blast issuing from the slot 31. By positioning the shell 39 near the outer end of the shell 35 and adjacent .to the widened portion 38 of the slot 31,- this second blast of air will also aid in producing a greater hardness in the rail tread surface at the end of the ed path. 7

Both of the air blasts are moved progressively from rail to rail behind the blowpipe or source of high temperature heat H. To this end, the

air shells

35 and 39 are supported or hung, by means of a suitable supporting member 43, from an auxiliary supporting arm 45 .which is slidably connected to the tubular member 11 bymeans of a collar 46 and may be held inany adjusted position thereon by a set screw 47. The inner or opposite end of the auxiliary supporting arm 45 has a block 48 mounted thereon which forms a support for an elongated cylindrical sleeve or tube 49 suitably secured to and depending from the underside thereof. A cylindrical supporting leg 50 is slidably mounted within the elongated sleeve 49 andresiliently urged downwardly by mounted thereon by means of a set screw 53, and the end of this arm 52 is provided with a caster or wheel 54 which is adapted to ride over the tread surface of each rail or along the track or plate 22 as the entire supporting frame structure F is moved by the travelling machine M. It will be seen that the above described construction provides a suitable supporting and carrying means for the

air shells

35 and 39 so that they may .beheld and properly spaced above the heated rails. It will benoted also. that the spring mounting of the leg 50 will prevent the auxiliary supporting structure from being bent or broken due to any irregularities encountered by the wheel 54.

Should it be found desirable to definitely separate the quenching devices Q from the heating blowpipe H, a water cooled baffle 55 may be provided between the air shell 35 and the heating head 30. As shown in Figs. 1, 3, and 4, this water cooled baille 55 comprises a thin box-like. shell or chamber composed of sheet metal, or other suitable material, and having an inlet pipe or conduit i 56 which extends through the top of the shell 3 and to a point near the bottom thereof so as to insure circulation of the water within the baffle. An' outlet conduit 51 is also connected to the top side of the bafiie to conduct the cooling water to a cooler for re-use, or to a drain. In

Fig. 3 it will be seen that the baflle 55 is provided on the bottom side thereof with a pair of gripping fingers or flanges 58 whose function it is to hold an apron or strip of packing 59. This apron or packingstrip 59 may be composed of asbestos, or other suitable material, and is adapted to drag overthe surface of each rail and thereby form a seal between the heating and quenching devices.

Inwardly bent grippingflanges 60 may also be provided on the side edges of the baflle 55 so as to slidably engage the lateral edges of the air shell 35 and hence assist in holding the balile in proper position.

The baflieis supported by means of a rod 5| which is welded or secured in any suitable manner to the side wall of the baffle and extends outwardly and horizontally therefrom and passes through an opening 62 provided in the leg 5|) which is in substantial alignment therewith. A counterbalance weight 63 may be provided on the free end of the supporting rod 6| and said rod thus fulcrums upon the leg 50 to support the baffle 55. The weight of the counterbalance 63 is such as to allow the bafile to have a firm contact with the tread surface of the rail as it passes thereover, but together with the cooperating flanges 69 will not allow said baflie to drop between the rails as it passes from one rail to the next. A

Shouldit be desired to have the heating-means H follow the contour of the rail tread surface more closely, the track or plate 22 could be Omitted In such event the wheels 2| and 54 would directly contact the rail tread surfaces and follow the contour thereof and thereby effect a corresponding movement in the heating torch H and in the baflle 55 also. In order to prevent the a could be provided in the sleeve 49 to prevent the leg 59 from sliding downwardly too far therein, and the hinge I9 could be constructed to prevent the'angle mem Fig. 5 shows a modified form of the quenching r l8 from dropping below the horizontal position an undesirable distance.

means Q which is similar to the arrangement 15 shown in Fig. 4 and described above, and'com-f prises a first air shell or chamber 35 having a second air shell or chamber 39' arranged perpendicularly thereto and attached to the first air shell 35 by means of brackets 42'. The second air shell 39' is provided with a slot 4| which is similar to the 'S10t.'. However, the first air shell 35' is provided with a slot'3'l' which may be either triangular ortrapezoidal in shape with the wider portion thereof at the. outer end of the shell which passes over, the extreme end of the rail. With such a construction the quenching air will issue from a slot 31 in amounts'which gradually diminish from a maximum at the end of the rail to a minimum at the end of the heated sectionso that a hardness in the rail tread surface will be produced which is greatest at the end of the rail and gradually diminishes and merges with the normal grain structure of the rail at the end of the treated section.

The apparatus described above is'designed particularly for the heat treatment 'of'railss'on similar metallic bodies in which the source of heat and quenching means. are moved transversely over the rail or body being treated. However, these same principles and features of construction may be embodied in a heat treating apparatus, which is particularly adapted to be moved longitudinally over the surface of the rail or metallicbody which is to be heat treated. Such apparatus may comprise thegsame general arrangement of structure and parts as has been". described above, employing a somewhat smaller heat torch provided with a'suflicient number of heating tips to heat uniformly the entire-width of, the tread surface of the rail being treated.

The structural details of the water cooled baiile and the quenching air chambers are changed, however, to meet the new requirements, and such changes will now be described.

Referring to Figs. 6 and '1, it will be seen that a suitable form of baflle adapted to be moved longitudinally along .the surface of a rail R comprises a casing Giha'ving water inlet and outlet conduits 66 and 61 respectively, and is very much the same as the baflle 55. However, the lower side thereof isv curvedat 68 to conform to the contour of the upper surface of -the rail and an apron 69 of asbestos or other suitable material is secured within such curved portion 68 so as toprovide a seal between the heating means and the quenching means. The quenching means likewise are similar to those described above and comprise an air shell or chamber III with which the baiiie may be slidably engaged by means of gripping flanges II. This air shell 10 is supplied with compressed air in any suitable manner and is curved at .12

on the lower side thereof. The curved portion I2, also corresponds to the contour of the tread surface of the rail and a slot 13 is provided therein so that the primary sheet of quenching air may issue therefrom and'be applied to the heated rail surface. The quenching means. also include a second quenching shell I4, similar, to the shell 39, having a slot I therein from which the'secand sheet of air may issue. This second air shell I4 is secured to the central portion of the rear side of the first air shell by means of brackets,

' .16 and in such a position thatthe sheet of air issuing from the slot "will be directed upon the tread surface of the rail substantially in the center of the heated path. Thus,.-the tread surface of the rail may be heated and subsequently cooled by means of a system. of air blasts which are applied in such a manner as to prevent a low pressure at the rear of a first air blast from causing the hardened area to be reheated.

It is to be understood that the above described methods and apparatus, which were explained particularly in their application to the hardening of the end portions of rail tread surfaces, may be appliedto the heat treatmentof other similarly shaped metallic bodies and certain features thereof may be applied to the hardening of local portions of' metallic bodies in general. It will also be understood that other means than those shown and described could be employed to support and move the heating and quenching means, or that I .such'means could be. manipulated manually.

Various other changes may be made in the construction and certain features thereof may be employed without others without departing from the. present invention or sacrificing .any of its advantages.

What-is claimed is:

' l. A method of hardening a portion of a surface of a relatively narrow metallic body which comprises progressively moving a localized high temperature heating medium over said surface portion which is to be hardened; progressively applying, perpendicularly to said heated surface portion behind said heating medium and under pressure, a primary sheet of quenching medium elongated transversely to the direction of movement of said heating medium; and following said primary sheet of quenching medium with a second sheet of quenching medium directed under pressure perpendicularly against said heated surface portion substantially at the center thereof and elongated in the direction of movement of said heating medium, said second sheet of quenching medium creating a high pressure area then progressively applying under pressure to.

such heated tread portion a primary quenching medium in the form of an elongated sheet which is directed perpendicularly upon and-is substantially coextensive with the length of the heated portion; and following this with an elongated secondary sheet of quenching medium which is directed under pressure perpendidularly upon said heated tread portion and is perpendicular to the primary sheet of quenching medium, said secondary sheet of quenching medium creating a high pressure areato prevent deflection of heat to-the rear of said primary sheet of quenching medium to thereby prevent reheating and consequent tempering of said tread portion.

3. A method of hardening a surface-of a relatively narrow metallic body which comprises ap-. plying a.high temperature heating flame to such surface. so as to heat such surface uniformly to an elevated temperature; during the application of the'high temperature heating flame directing two elongated sheet-like blasts of. quenching air perpendicularly upon said heated surface, one ofsaid blasts being positioned behind the heating flame and extending across the heated path, and the second being arranged perpendicular to and behind the first and substantially in the center aroaaos of the heated path to create a high pressure area at the rear of said first blast of quenching air;

. and moving the metallic body and said heating and quenching means relatively to one another.

4. A method of hardening a portion of the tread surface area of a rail, which comprises progressively moving a source of high temperature heat transversely over said portion to betreated, said source of heat being adapted to heat said surface portion to an elevated temperature; progressively applying perpendicularly upon such heated area an elongatedsheet-like blast of air which is substantially coextensive with the length of said heated area; and following such first air blast with a second elongated sheet-like blast which is directed perpendicularly upon the heated area and is substantially perpendicularto the first blast and adapted to further cool the heated area and prevent reheating thereof, said second sheet-like blast of air creating a high pressure area at the rear of such first air blast to preventdefiection of heat to the rear of such first air blast and consequently to prevent reheating and ,tem-

pering of said tread surface area.

5. A method of hardening a portion of the tread surface area of a rail, which comprises progressively moving a source of high temperature heat transversely over said portion, said source of heat being adapted to heat said tread surface portion to an elevated temperature; progressively moving an elongated sheet-like blast of air transversely over the heated area, said blast of air being shorter than the heated area and extending from the extreme end of the rail to a point short of the end of the heated area, and following such first elongated air blast with a second elongated sheet-like blast of air which is directed perpendicularly upon the heated area adjacent one end thereof, is substantially perpendicular to the first blast of air, and is adapted to further cool the heated area and prevent reheating thereof, said second sheet-like blast oi. air creating a high pressure area at the rear of such first air blast to prevent deflection of heat to the rear of such first air blast and consequently to prevent reheating and tempering of said tread surface area.

6. Apparatus for heat'treating a surface of a relatively narrow metallic body comprising, in combination, a high temperature heating means disposed above said surface; means for directing a sheet-like blast of quenchingmedium perpendicularly against said surface at the rear of said heating means, said last-named means comprising a casing having a wall parallel to said surface and formed with a narrow elongated slot therein; a heat insulating member disposed between said heating means and said casing; and mechanism for moving said heating means, said casing and said member'as a unit parallel to said surface,

said heat insulating member comprising a chamher for cooling fluid, means to circulate cooling and formed with a narrow elongated slot there-' in; a heat insulating member disposed between said heating means and said casing and including a heat resistant seal engaging said surface to separate the heating means from said casing; and mechanism for moving said heating means, said casing and said member as a unit parallel to said surface. v

8. Apparatus for hardening the tread surfaces of a plurality of rails arranged side by side comprising, in combination, a frame; a high temperature heating means; means on said frame for directing a sheet-like blast of quenching medium substantially perpendicularly against said surfaces, said means comprising a chamber having a narrow elongated slot in the lower wall thereof; mechanism for moving said frame transversely of said tread surfaces; a support pivotally connecting said heating means. to said frame for frame for directing a sheet-like blast of quenching medium substantially perpendicularly against said surfaces,said means comprising a chamber having a narrow elongated slot. in the lower wall thereof; a heat insulating bame disposed between saidheating means and said chamber;

mechanism for moving said heating means,

. chamber and baiile transversely over the tread surfaces being treated; a first support secured to said heating means and pivotally connected to said frame; a second supportsecured to said balls and movably mounted on said frame; and

means secured to each of said supports and progressively contacting said tread surfaces to move said heating means and said baflle in a path parallel to the contours of said tread surfaces.

CECIL V; EsKRlDGE.