US2321645A - Apparatus for flame hardening of articles - Google Patents

Description

June 15, 1 943. O BlSHOP ETAL 232L645 APPARATUS FOR FLAME HARDENING OF ARTICLES Filed Aug. 5, 1940 5 Shee ts-Sheet 1 Q I ,-x 3 1: I16:

E I 75 5 I10 b v m 151, I 4 0 5 7 a c 1 I6 I66 35 1/9 1Z9 A I0 7'0 MIX ING VALVE grwam/to'u IQME; BIS/'0 Lloyd L. BABc dc June 15, 1943.

J. 0. BISHOP ETAL APPARATUS FOR FLAME" HABDENING OF ARTICLES Filed Aug. 3, 1940 5 Sheets-Sheet 2 June 15, 1943. 4 J. o. BISHOP ETAL 2,321,645 I APPARATUS FOR FLAME HARDENING OF ARTICLES I Filed Aug. 5, 1940 l 5 Sheets-Sheet 3 Jhmss 0. 5 1 L/oyd L. Linapoug June 15, 1943. J. o. BISHOP ETAL- APPARATUS FOR FLAME HARDENING ARTICLES Filed Aug. 5, 1940 '5-Sheets-Sheet 4 IIIII'IIHII I MES 5/560 7 I I Ll yd fimscoclg I June 15, 1943. J. o. BISHOP ET AL APPARATUS FOR 'FLAME HARDENING OF ARTICLES Filed Aug. 5, 1940 5 Sheets- Sheet 5 ,4 Z. 648caclg Patented June 15, 1943 APPARATUS FOR HARDENING OF ARTICLES.

James 0. Bishop, Torrance,"and Lloyd L. Bab

cock, Compton, Calif., assignors to The Nation Supply Company, Pittsburgh,v Pa., a oorpi' tion of Pennsylvania Application August 3, 1940, Serial No; 350,196 11 Claims. (01. 266-4) This invention relates to a method of and apparatus for the treating of metallic surfaces to flame-harden the same and is more particularly directed toward the provision of a method and apparatus for flame-hardening the teeth of a gear.

In the flame-hardening of a metallic surface, it is essential to provide a method of producing uniform flame distribution and heating over the surface to be hardened and in such manner as to avoid thebuilding up of stresses within the body so treated and the localization of the heat as applied to the surface.

It is also essential to provide a method and apparatus which makes possible very accurate control of the time of the treatment, as well as to insure the even distribution of the flame and heating over the entire surface during the said time interval.

In the particular problem of flame-hardening a gear tooth, it is desirable that themethod and apparatus be susceptible of producing a uniform heat treatment of the gear tooth from its opposed or opposite flanks simultaneously and over the entire area of such flanks.

It is therefore an object of this invention to provide a method for the flame-hardening of the opposed flanks of the gear by simultaneous directing of flames over the entire surface 7 of the flanks in a direction substantially normal to the flanks and oscillating the flames as directed in a curved path-substantially parallel with the said flanks.

Another object of this invention is to provide an apparatus for the flame-hardeningof the gear tooth, which apparatus includes a pair of oppositely disposed and directed torches having a multiplicity of flame-directing apertures extending substantially the length of the flanks of the gear tooth, and a means for supporting the torches in a position parallel with the flanks, and means for imparting an oscillatory motion to the supporting means to move the torches in a curved path substantially parallel with the flanksto obtain distribution of the flames evenly over the flanks and. from the opposed sides of the gear tooth.

Another object of this invention is to provide a torch which oscillates in a substantially elliptical path.

. Another object of this invention is to provide a method and apparatus for directing flame against a surface to be hardened, including flame distribution members including a plurality of flame producing apertures, and a means for increasing the heat intensity in the fuel as burned at the point of application of the flame to the to the surface to be hardened.

Another object of this invention is to produce a method-and apparatus wherein the time of heat or flame application to a surface may be accurately regulated and whereby the heat-directing means is maintained during such period of time adjacent the surface to be heat-treated.

Another object of this invention is to produce a flame-hardening method and apparatus which embodies the provision of a means operable to maintain a wide range of mixtures of heat producing fuel and gas required for combustion thereof and which is operable over a wide range of flow rates to maintain such efliciency.

Another object of this invention is to provide a flame-hardening method and apparatus which includes safety means operable to prevent accidental over-heating of the apparatus by controlling-the flow of the combustible gas utilized until circulation of the requiredcooling medium is established.

Other objects and "advantages of this invention it is believed will be apparent from the following detailed description of a preferred embodiment thereof as illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a perspective view of the apparatus embodying this invention and diagrammatically illustrating the method of operation thereof.

Figure 2 is a fragmental perspective view thereofupon an enlarged scale.

Figure 3 is a longitudinal sectional view of the mixing valve embodied in our invention.

Figure 4,is a diagrammatic side elevation partly in section illustrating the flame-applying or torch means in operable position with respect to a method and apparatus for heat-treating the i the surfaceto be flame-hardened.

Figure 5 is a view similar to Figure 4 illustrating the position of the parts .with the flamedirecting or torch means raised to inoperable position.

Figure 6 is a detached detail view illustrating the clutch shifter element with the parts in the position of Figure 4.

Figure 7 is a view similar to Figure 6 illustrating parts.

Figure 9 is a fragmental view partly in section illustrating the construction of the half-revolu-.

tion clutch embodied in our invention.

Figure 10 is a sectional view taken substantially on the line Ill-l of Figure 9.

Figure 11 is a sectional view illustrating the construction of the adjustable supporting standard for the article to be flame-hardened.

Figure 12 is a sectional side view illustrating the details of construction and operation of the means provided for imparting an'oscillatory motion to the torches.

Figure 13 is an enlarged sectional elevation of one of the torches embodied in our invention.

Figure 14 is a sectional view taken substantially on the line I i-I4 of Figure 13 and illustrating the position of the torches with relation to a section of a gear tooth.

Figure 15 is a diagrammatic view partly in section illustrating the safety device provided to prevent the flow of combustible gas to the torches until flow of the cooling medium for the torches has been established.

Figure 16 is a fragmentary sectional view illustrating the arrangement of the part of the valve of Figure 15.

In carrying out the method embodying our invention, we prefer to utilize the apparatus as illustrated in the accompanying drawings, which apparatus includes generally a universal work supporting unit A, a flame or torch unit B, a torch unit timing and oscillating unit C which also functions to support the torch unit B, and a fuel and cooling medium supplying unit D for supplying fuel', gas necessary for supporting combustion of the fuel, cooling means for the torch unit,. and the cooling medium required for quenching the flame-hardened teeth or surface after the flame treatment.

The method embodying our invention comprises the supporting of the surface to be hardened, as illustrated, the opposed flanks of a gear tooth, the providing and directing of flames over the entire surfaces of the opposed flanks of the gear tooth in a direction substantially normal to the surfaces and parallel therewith, and the distribution of the flames. as supplied evenly over the surfaces of the tooth by oscillating the flames in a curved'path substantially parallel with the plane of the surface to be flame-hardened, and then the proper quenching of the flame-treated surfaces in order to obtain the desired surface hardening thereof.

In order to effectively carry out this method, the apparatus as illustrated in its preferred form includes a base frame I upon which there i supported a standard 2, upon which there is sup ported the universally mounted work head or table 3 of the unit A. As will hereinafter be set forth, this table 3 is mounted so as to permit rotation in a horizontal plane, adjustment vertieach torch to fit in the recess or space between the teeth so as to be substantially parallel thereto and uniformly spaced throughout the entire length of the flanks 6 and l of the gear teeth 4.

Means are provided for supporting the torches l0 and II upon a supporting means so that the torches may be oscillated in a direction parallel with the flanks 6 and 1 and in a curved path in the arallel plane defined by the flanks 6 and I so as to provide for and insure uniform distribution of the flame over the said flanks 6 and I and to avoid all possibility of concentration of any single flame upon a point upon such flank surfaces.

In order to accomplish this result, the torches secured to the oscillating bar E2 to permit aligning the torch surfaces 8 and 9 with the flanks 6 and 7. Means are provided for reciprocating the bar l2 and hence the torch unit B parallel with the flanks 6 and l, which means include a bearing support l6 for the bar l2, which bearing support is carried upon trunnions H of a bracket iii. The opposed end of the bar I2 is enlarged to receive a bearing H) which is mounted eccentrically with relation to the axis of the power shaft 20 so that rotation of the shaft 20 imparts an oscillatory movement to the bar l2.

The torch supporting, timing and oscillating unit C includes a standard 2|, likewise supported upon the frame l, upon which standard there is mounted for vertical adjustment the torch supporting head 22.

Vertical adjusting means are provided between the standard 2! and the head 22 through the medium of adjusting screw and wheel 23 and a clamping unit 24.

Carried by the head 22 isa carriage 25 which is slidably supported in ways 26 for vertical reciprocation. A spring 21 is provided for counterbalancing the weight of the carriage 25 and its attendant parts so that the same may be raised or lowered with a minimum of effort. The carriage 25 supports the motor 28 which provides the source of power for driving the power shaft 20 through a worm 29 and worm wheel 30 drive. An extension shaft 3| is positioned in axial alignment with the power shaft 20 and is rigidly coupled thereto by means of a sleeve32 which has a key connectionwith each of the shafts 20 and 3|. An outboard bearing 33 is provided for the outer end of the extension shaft 3|.

Means are provided for varying the intensity or magnitude of the oscillatory movement imparted to the bar I2, providing both a flne adjustment and an adjustmentwhich permits of a wide variation in intensity and in the path of oscillation given to the torches l0 and II. This adjustcally to position the work, and supporting of the vided with spiral gear teeth requiring that the ment is particularly important to enable the changing of the torches I ll and-H to vary the type and characteristics of the flame utilized for the flame-hardening as well as to permit adjustment of the eccentric means so that the flames as emitted from the torches l0 and II are uniformly directed over the surfaces to be flamehardenedwithout concentration of the effect of the flame at any particular point or region during the flame-hardening operation.

torches l0 and H be slightly curved, to permit In order to provide for these'adjustments, the sleeve 32 has an outer periphery which, provides a, cylindrical surface 34 which is not coaxial with the axes of the shafts 20 and 3|. Mounted on this eccentric surface 34 is an outer sleeve 35 which may be rotated to any desired angular position relative to the inner sleeve 32 and may be maintained in such desired position of adjustment by means of a set screw 36. The outer surface of the outer sleeve 35 is also cylindrical but not concentric with the surface34. By this arrangement the magnitude of the eccentric mounting for the bearing I9 is capable of fine adjustment to enable adjustment of the oscillatory motion imparted to the torches l6 and II. It will be apparent that by turning the outer sleeve 35 relatively to the inner sleeve 32, that any desired degree of eccentricity may be obtained ranging from zero to the sum of the individual eccentricities provided for by the sleeves 32 and 35.

Means are also provided for obtaining a much greater degree of adjustment of oscillation than is permitted through the variation of the eccentricities as hereinabove set forth. This additional adjustment is accomplished through the medium of the bracket l6 which supports the bearing |6 through which the bar I2 is reciprocated and by mounting this bracket upon the carriage 25 so that it may be reversed end for end as illustrated in the dottedlines in Figure 12 to vary the position of the bearing I6 along the length of the bar l2, and also by reason of the fact that the bracket I6 is secured to the carriage 25 by means of bolts 31 positioned within the slot 38.

Means are provided for raising and lowering relation to the work to be flame-hardened and a as illustrated, this means includes a forwardly projecting foot-piece 39 of the head 22 which is adapted to be engaged by a cam 46 mounted upon a shaft 4| carried by the carriage 25. The shaft 4| carries a sprocket 42 over which a chain 43 is trained and the chain 43 is also trained over a sprocket 44 mounted through the medium of a half-revolution clutch upon the power shaft v2|).

As th half-revolution clutch is engaged to. rotate the sprocket 44, it will be apparent that the cam 46 is rotated to lift the carriage 25 upward and thereby raise the torches l and II from the operative position as illustrated in Figure 4 to the inoperative position illustrated in Figure 5.

Means are provided for timing the operation of raising and lowering the torches l0 and H so that the same'are maintained in the operative position of Figure 4 for a definite predetermined period of time before the half-revolution clutch is engaged to discontinue the flame-heating operation of the work. This means includes the formation of the threads 45 upon the extension shaft 3| and a cooperating half nut 01' follower element 46. The head portion 41 of the follower 46 is provided with threads (not shown) which mate with the threads 45 and cause the follower 46 to move axially along the threads 45 when the extension shaft 3| is rotated.

Means are provided for slidably supporting the follower 46, which means include a square bar 48 which passes through a square hole 49 formed in the follower element 46. The bar 48 is sup ported in bearings 56 on the carriage 25. I

A trigger is pivotally connected with the handle 52 of the follower 46 and is provided with a lug 53 which is adapted to slide in contact 4 contact with the guideway 54 and thereby holds the follower 46 in engagement with the threads 45. A notch 56 is provided in the guideway 54 into which the lug 53 drops when it reaches the position of the notch 56. When the lug 53 drops into the notch 56, the weight of the handle 52 overbalances the head 41 of the follower element 46, thereby turning the square bar 46 in its bearance around the extension shaft 3|.

' ings 50 and disengages the head 41 from' the threads 45.

The turning of the square bar 46 not only serves to disconnect the follower element 46 from the threads 45, but also acts to cause engagement of the half-revolution clutch and thereby cause the sprocket 44 ,to rotate the cam and raise the carriage 25 and the torches l0 and II.

As herein illustrated, the half -revolution clutch (Figures 9 and 10) includes the hub 51 secured to the extension shaft 3| and the rotatably mounted driven member 58 which carries the sprocket 44.

The-rotatably mounted member 56 is provided with a longitudinal bore 59 extending there-v through and adapted to register with a pocket 66 formed in the lateral face of the hub member 51.

' A transverse passage 6|, closed at its outer end by means of a plug '62 intersects the longitudinal bore 59 at a point between its ends.

A clutch shifter late 63 is secured and supported upon the square bar 48 and is located adjacent the rotatable member 56.

A' central opening 64 is provided in the shifter member 63 large enough to provide for clear- Adjacent this opening and on opposite sides thereof are a pair of like projections 65 and 66 which extend beyond the end surface 61 of th plate 63. ,The

' projection 65 is adapted to register with the longitudinal bore 59 when the follower element 46 is in the engaged position shown in Figure 4.- Similarly the projection 66 registers with the. longitudinal bore 59 when the lug 53 enters the notch 56 and the follower element 46 is disengaged as shown in Figure 5. Balls 66 and 69 are positioned in the longitudinal bore 59 and a ball 16 is positioned in the transverse passage 6|. The ball I6.

the member 58 remains stationary. However when the square shaft 48 tilts the shifter plate 63 to bring the lug 66 out of engagement with the ball 66, the ball 69 moves against the surface Ill as the spring crowds the ball 10 between the balls 66 and 69, and thisforces the ball 66 into the pocket 60 when the rotating hub 51 moves the pocket 60 into registry with the bore 59. As the pocket 66 is too shallow to receive the full diameter of th ball 56, the ball 66 is caught between the walls of the pocket 60 and the wall of the longitudinal bore 59, and thereby forms a positive driving connection between the hub 51 and the member 56. The member 56 thereby rotates the sprocket 44, causingthe cam 40 to turn and the carriage 25 drops of its own weight.

'I'he member 56 and sprocket 44 continue to revolve only until the longitudinal bore 59 comes into alignment with the projection 66 and the parts are arranged so that this travel amounts to one-half revolution. At this point of movement the sloping side of the projection 66 engages the ball 69 and forces it back into the longitudinalbore 59 which inturn raises the ball I permitting the ball 68 to move out of the pocket 60, disrupting the driving connection. When the clutch shifter 83 is tilted back to the position illustrated in Figure 7, the clutch is again engaged for a half revolution and consequently the carriage is again raised to the position shown in Figure 5.

As the extension shaft 3|v is rotated at substantially constant speed, the distance travelled by the follower on the threads determines the time that the carriage remains in its lowered position and until the lug 53 drops into the recess 56. Therefore the act of engaging the head 41 of the follower element at any pre-selected point along the threads 45 determines the time interval which must elapse before the torches are raised from the" work. We utilize this relationship for accurately regulating the time interval by providing an adjustable stop member I2 adapted to contact the lug 53.

The adjustable stop member I2 is carried upon a screw I3 carried by the carriage 25 and the position of this lug I2 ,is calibrated to indicate the number of seconds which will elapse-as the follower element 46 moves from the pre-selected point to the notch 56. Thus as illustrated in Fi that the standard 2 forms a hydraulic cylinder for the reception of a piston 84 which may be raised or lowered in the cylinder by the introduction of fluid under pressure into the interior of the piston 84 through the inlet 85. Ports 86 communicate through the piston 84 with the lower end of the cylnder 2 and owing to the difference in area between the inside and outside of the piston 84, the fluid pressure acts to raise the piston in the cylinder.

A clamping device 81 is provided for maintaining the piston at any desired height. Carried on the piston 84 is a crosshead 88 which has bearings 89 for reception of the trunnions 90 of the ring 9|. A worm-gear wheel 92 is fixed upon one of the trunnions 90 and may be rotated to any desired angle by means of -a cooperating worm 93. A barrel 94 is journaled upon spaced bearings 95 carried on the ring 9| and the worksuppporting table 3 is secured to the barrel 94. It will thus be apparent that a universal mounting is provided for the table 3 which permits raising or lowering the table 3, its rotation or its ure 8, the follower element 46' is positioned by the I stop member I2 to require 14% seconds to reach the notch 55. The time scale 14 is provided upon the carriage adjacent the stop member I2 to enable an easy determination of this time element as the screw I3 is rotated to adjust the position of the stop member I2.

Means are provided for rotating the particular tooth which has been flame-treated away from the position of the torches l0 and II and into a position under a quenching bath. Thisquench- ,ing bath is conveniently provided by a pair of cooling nozzles I5 which direct fluid against the flanks 6 and I of the tooth which has been heated. The quenching fluid flows off the tooth 4 across the table 5 and falls into a sump IS. A shield 11 may be provided to direct excess fluid into the sump.

Indexing means are provided to facilitate the rapid and accurate movement of the heated tooth to the proper position beneath the cooling nozzles I5 and also to position a second tooth in position with relation to the heating torches I0 and II. As herein illustrated, this indexing means includes a radial lever I8 which carries a projection I9 adapted to drop between adjacent teeth of the gear. Arcuate" movement of the lever I8 is limited by a pair of stops 80 and 8| positioned upon a stationary arm 82 mounted in the work support 2. These stops 80 and-BI are so positioned that when the lever is swung by .the operator from theposition shown in Figure 2 to the position shown in Figure .1, the heated tooth is brought into position beneath the cooling nozzle I5. The lever I8 is provided with a pivoted joint .83' which enables the operator to lift the projecting lug I9 from between the gear teeth and to swing the lever I8 back against the' stop 8| and reengage the projecting lug I9 between a pair of new teeth.

As heretofore set forth, the work supporting means provides a rotatable support for the work and the preferred form of this construction is illustrated in Figure 11. Here it is illustrated ing the flame-hardening operation.

tilting to any desired angle.

The torch means herein illustrated are preferably of the following construction and are substantially duplicates except that they are right and left-handed. Each torch is proportioned so that it'may be inserted adjacent the gear teeth. The broad sides of the torch from which the flame is directed are designated as the active faces 8 and 9. Formed in the active faces 8 and 9 are a large number of orifices 95, each of which has a counterbore 98 forming an enlarged chamber upon the faces 8 and 9. The large number of orifices are distributed over the area of the active faces and hence the large number of individual flame jets combine to function as a single mat of flame. The orifices 95 communicate with one of a plurality of lateral fuel passages 91 which in turn leadfrom a main header passage 98. Cooling passages are also formed in the torch to permit a cooling fluid to be circulated through the torches to prevent overheating dur- As illustrated, these cooling passages are the passages 99, I00, and It, connected by lateral passages I02 and I03. Cooling fluid, such as water, enters through the inlet I04, circulates through the passages 99, I02, IOI, I03, and I00, in the order named, and then discharges through the outlet I05. Hot water from the outlet I05 is delivered to the cooling trough I06 mounted on the carriage 25 and is then carried away through the discharge pipe I 01.

The torches I0 and II are provided with through-bores I08 interposed between the fuel orifices 95. These orifices extend completely through the torches and provide air delivery apertures through which air is delivered into the flames upon the faces 8 and 9 of the torches I0 and II, respectively. The torchesas herein illustrated are particularly adapted for use with natural gas, although their use is not limited thereto. Natural gas is used as a source of the fuel to produce the flame because it has been found to be less expensive than acetylene and because it has been found that the results accomplished through the use'of this less expensive fuel are just as satisfactory. Just as when acetylene is used, the natural gas is mixed'with oxygen through the medium of a mixing means, as will hereinafter be described.

It has been found that when using natural gas, it is necessary to obtain a reduction in velocity of the gas mixture to prevent the flame produced on the surface of the torch from being blown out. This reduction in velocity we have accomplished by forming the enlarged cou'nterbores 94. We have further found that we are enabled to reduce the time required for heat-treating the flanks of the gear teeth by the intensification of the heat produced at the surface by the use of the throughbores I08. As an example, before the throughbores were formed through the torches, it required approximately 70 seconds to heat the flanks 6 and 1 of the teeth 4 to the desired depth. After the through-bores I08 were formed, the

same depth of heating was attained in approxi- Means are provided for regulating the supply of natural gas, oxygen, and the-cooling fluid or water for the torches I and II and for controlling the type and amount of, quenching fluid delivered to the nozzles 15. p This means as here- I43 adapted to seal off around the pipe I39. When the sleeve is positioned as shown in the upper half of Figure 16, no flow is permitted, but when the sleeve is located as shown in the lower half of Figure 16, flow takes place outwardly through the ports I40 bore of the sleeve I42 and back through ports I4I. Both valves H6 and H1 are shifted simultaneously by the lever H8.

Means are provided for preventing 'flow of combustible mixture through the control valve I I6 until water under pressure is made available for circulation through the cooling passages of the torches I0 and II, respectively. This safety device thus prevents accidental overheating of the torches through failure to circulate cooling water. As this means is illustrated (Figure it includes a diaphragm I44 connected by a rod I45 to actuate an interference lug I46 when suf, flcient water pressure exists in the cooling line I35. This pressure forces the diaphragm I44 down, moving the interference lug I46 out of If for any reason the water pressure is too low,

in illustrated includes a control stand I09 which trol valve II1, governor H5 and through the piping I to the mixing valve I2I. The pressure in the governor I I5 is indicated by the manometer II3, there being a connecting pipe I22.

Similarly, natural gas is supplied through a line I23 and passes through the flow meter H0 and control valve II 6 and governor II4 through the piping I24 to the mixing-valve I2I, The

manometer II2 indicates the gas pressure in the governor I I4.

Air under pressure passes from the supply line I25 through the valve I26 to the supply line' I21 for the cooling nozzles 15 when it is desired to cool with air alone or with a mixture of air and water. A gauge I28 may be provided to indicate the pressure of the air delivered into the supply line I21.

Water is supplied through the water supply line I29 to the branch pipes I30 and I3I which lead to the valves I32 and I33, respectively. From the valve I32 water may be admitted into 'the' quenching line I21 and its pressure may be indicated by the gauge I34. From the valve I33 the water enters the cooling line I35 by way of the connecting pipe I36. A gauge I31 is provided for indicating the water pressure in the line I36.

The control valves H6 and H1 for the natural gas and oxygen are substantial duplicates and therefore a description of one such valvewill sufiice. These valves are preferably constructed to include a plug I38 (Figure 16) which is positioned in the pipe I39 leading from the flow meter IIO to the governor II4.

Ports I40 and I are formedin the wall of the pipe I39 on opposed sides of the plug I38. A shiftable sleeve I42 is slidably mounted upon the pipe I39 and is adapted to permit flow into the governor H4 or to prevent such flow when desired. The sleeve I42 is provided with a pair of spaced annular flanges which carry packing .valve I2I (Figure 3).

the diaphragm I44 remains in the upper position, thereby holding the interference lug I46 between the valve sleeve I42 and the abutment I41 preventing opening of the valve H6 and as the valves H6 and. I I1 are connected by a common shifting lever II8, neither valve H6 nor II1 may be open when this interference is met. l

Means are provided for mixing the combus tible mixture of natural gas and oxygen which means as herein illustrated include the mixing I In Figure 3 the mixing valve I2I is illustrated inverted from its actual operating position for the reasons of clarity of description. This mixing valve has an oxygen inlet from the connecting pipe I20 and a natural' gas inlet from the connecting pipe I24 and a common outlet I48, both of which inlets and outlets lead to and from the body I49. Within the threaded into the body I49 and maintains a lan-' tern. ring I 53 in contact with spaced packings annular port I8I.

directed flange I51. The lower end of the flange I51 cooperates with the body I49 to define an annular orifice I58 leading from the chamber I5I to the outlet I48.

A plunger I59 is threaded into the sleeve I56 and has a. tapered valve head I60 adapted to cooperate with the annular flange I51 to form an This port establishes communication between the annular chamber I50 and the outlet I48 by way of the windows I62 in the sleeve I56 and the lantern ring I53. The plunger I59 is provided with a micrometer scale I63 which permits of very accurate setting of the size of the annular port IGI. Similarly, a micrometer scale (not shown) is provided for regulating the size of the port I58. These port openings may therefore be accurately regulated to meet the requirements of the particular torch in use, and may be independently varied to change the proportions of the mixture as desired:

It will also be noted from the foregoing that the annular ports I58 and I6I are separated only by the relatively thin annular flange I51, and that therefor the oxygen and natural gas are intimately mixed on a circular periphery near the upper end of the valve chamber I64. It has been found that this form of mixing valve l2! operates very satisfactorily over a very wide range of port openings.

Branch pipes I65 connect the outlet pipe I48 with the torches l and l I.

The operation of the apparatus embodying our invention to carry out the method thereof is as follows:

A gear is placed on the table 3. It is held in place by means of locking members I66. The table 3 is elevated to the proper height and tilted enough to bring the flanks of the gear tooth 4 adjacent and parallel with, and axially spaced from, the faces 8 and 9 of the torches l0 and II With the carriage in its upper position as illustrated in Figure 5, and with the lug 53 in the notch 56,

the motor 28' is started. If the observed path of oscillation of the torches Ill and H is not the desired one, the sleeve and the bracket l8 may be adjusted until the proper path is obtained. In any event, the path of the torches is a closed, curved path which is not circular but more close- 1y approximates an elliptical path, though perhaps not an elliptical path in the true, precise mathematical sense. It will however be hereinafter referred to as an elliptical path.

' The proper valve settings are made on the control stand to insure proper delivery of combustible gas, oxygen and cooling water to the torches l0 and II and the cooling fluid to the quenching nozzle 15;

Either air or water, or any combination thereof, may be used as a quenching medium, depending upon the particular steel employed and the depth of hardening desired. The lever I I8 is then actuated and the torches lighted.

The trigger 5| of the follower element 46 is then actuated to release the lug 53 from the notch 56 and the follower element 46 is manually moved along the guideway until the lug 53 strikes the adjustable stop I2 which has previously been set at the desired point.

The handle 52 isthen raisedto bring the head 41 of the follower element 46 into cooperative engagement with the screw threads 45. The lug 53 contacts the guideway 54 to prevent disengagement of the follower element 46 and screw threads 45 while the follower element 46 is moved along the guideway 54 by the screw threads 45.

The act of raising the handle 52 turns the square bar 48 and thereby moves the shifter plate 63. This in turn effects engagement of the halfrevolution clutch and causes the cam '40 to revolve and permit the carriage to gravitate to its lowermost position, thus bringing the torches i0 and I i into operative position adjacent the flanks 6 and I of the tooth 4.

The torches are continuously oscillated in the curved, closed, substantially elliptical path by means of the rod or bar l2 and this oscillation prevents overheating at points on the flanks. At the end of the selected time interval, the lug 53 drops into the slot 56. This automatically releases the follower from the screw threads 45, efiects engagement of the half-revolution clutch, rotates the cam to lift the carriage 25, and hence raises the torches away from the heated tooth 4. The operator promptly swings the radial lever 18 until it engages the stop 80, thereby rotating the gear 5 to bring the heated tooth .4 into position under the cooling nozzle 15 and also presents a new'tooth for the flame treatment under "the torches l0 and II. The operator then lifts the lever 18 to clear the projection 19, swings the lever 18 back against the stop 8!, and releases the lever. This brings the projection 19 into position between two teeth ready for the next indexing movement. The handle 52 is again moved to its starting position by the operator and the cycle is repeated until all of the teeth in the gear table 5 have been heator flame-treated as desired.

Having fully described our invention, it is to be understood that we do not wish to be limited to the details herein set forth, but our invention is of the full scope of the appended claims.

We claim:

1. In a device. for heat treating the teeth of a gear, the combination of, a torch positioned adjacent the flank of a tooth and extending along the flank for substantially the full length thereof, means on the torch for directing a mat flame at right angles against the entire flank surface the gap between two teeth andextending along y the flank of one of them for substantially the full length thereof, means emitting a mat flame from the torch adapted to simultaneously heat the entire flank surface which is to be heat treated, the flame being directed substantially at right angles to the flank surface, and means for imparting an elliptical movement to the torch.

3. In a device for flame hardening the teeth of a gear, the combination of, atorch positioned adjacent the flank of a tooth and extending along the flank for substantially the full length thereof, means on the torch for directing flame simultaneously against the entire flank surface which is to be hardened, means for imparting an oscillatory movement to the torch, means for automatically removing the torch from the proximity of the flank after a predetermined time interval, and means for quenching the heated surface of the flank.

4. In a. device of the class described for flame hardening the teeth of a. gear, the combination of, a power shaft provided with an eccentric, means to rotate the power shaft, a member having a rotatable connection with said eccentric, a relatively stationary support having a slidable engagement with said member, a torch supported on said member and adapted to be positioned adjacent one of the teeth of the gear, the torch being provided with means for directing flame against the flank of said tooth, and a time controlled device for removing the torch from the vicinity of the heated tooth flank after a predetermined interval.

5. In a device for imparting an oscillatory motion to a torch, the combination of, a relatively stationary member having a shaft rotatably mounted thereon, means to rotate the shaft, an eccentric carried on said shaft and arranged to be radially adjusted .relative thereto to vary the degree of eccentricity, a-bar having a rotatable connection with said eccentric, a relatively stationary support adjustably positioned upon said member, a bearing element pivotally carried on said support and adapted to receive said bar in sliding engagement, and means mounted on the bar adapted to support a torch.

6. Apparatus for hardening gear teeth, comprising in combination, a torch adapted to be time the torch'is maintained adjacent the tooth flank, including a screw associated with the positioned in the gap between adjacent teeth of the gear, the torch'having an active face adapted to lie in relatively closeproximity to the flank of one of the teeth, a plurality of openings in the active face of the torchadapted to direct flame jets against the flank of the tooth, a

:plurality of air ducts passing laterally through the torch and communicating with said active face adjacent said openings, and passage means in the torch adapted to supply a combustible fluid to each of said openings.

7. In a device for flame hardeningthe teeth of a gear, the combination of, a torch adapted to be positioned in the gap between adjacent teeth of the gear, means on the torchfor directing flame at right angles simultaneously against the entire flank of one of said teeth, means including a carriage for supporting the torch in operative posi tion relative to said flank, means mounted on the carriage adapted to impart an oscillatory movement to the torch, and means for shifting the position of the carriage whereby the torch may be moved out of said gap and away from the flank of said tooth.

- 8. In a heat treating device of the class' described, the combination of, a torch having means means for directing flame against an adjacent surface,'means including a carriage for supporting the torch in operative position with relation to said surface, a power shaft rotatably mounted on the carriage, drive means for rotating the, power shaft, operative connections between the power shaft and the torch whereby rotation of the power shaft serves to impart an oscillatory movement to said torch, and means driven from said power shaft selectively operaple to shift the position of the carriage.

9. In a device of the class described, the combination of, a rotatably mounted power shaft, drive means adapted to rotate the power shaft, a torch adapted to be positioned adjacent a gear tooth, means associated with the power shaft adapted to impart an oscillatory movement to the torch, means for regulating the length of power shaft and a cooperating follower element adapted to move axially of the screw, mechanical means for shifting the torch to a position remote from said flank, and means including a clutch automatically operable to effect a driving connection between said drive means and said mechanical means upon the follower element reaching a predetermined position axially of the screw.

10. In a heat treating device of the class described, the combination of, a torch having means for directing flame against an adjacent surface, means including a carriage for supporting the torch in operative position with relation to said surface, an externally threaded lead screw rotatably mounted on said carriage, a power source adapted to rotate said lead screw, a follower element selectively engageable with said lead screw and adapted to be translated along thecarriage in a direction axially of the lead screw, mechanical means for shifting the position of the carriage whereby the torch may be moved away from said surface, and means including a clutch automatically operable to effect a1driving connection between said power source and said mechanical means, upon the follower element reaching a predetermined position upon the carriage.

11. In a device for flame hardening a gear tooth, a pair of substantially oppositely directed torches having a multipilcity of flame directing apertures extending substantially the length of the flanks of the gear tooth, means for supporting the torches in a position parallel with the said flanks, and means for imparting an oscillatory movement to the supporting means to move the torches in a curved path substantially pare allel with the said flanks to distribute the flames evenly over the-said flanks and obtain uniform flame heating thereof,

JAMES o. BISHOP. LLOYD L. BABCOCK.

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