US2495055A

US2495055A - Method and apparatus for flame hardening and annealing

Info

Publication number: US2495055A
Application number: US562312A
Authority: US
Inventors: John J Crowe
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1944-11-07
Filing date: 1944-11-07
Publication date: 1950-01-17
Anticipated expiration: 1967-01-17

Description

-several passes of the name.

Patented Jan. 17, 1950 METHOD AND APPARATUS FOR FLAME HARDENING AND ANNEALING John J.` Crowe, Westiieid, N. J., assigner to Air Reduction Company, Incorporated, a corporation of New York Application November 7, 1944, Serial No. 582,312

8 Claims.

This Vinvention relates to a method and apparatus for heat-treating metal surfaces with heating flames.

It is the usual procedure in heat-treating .metal surfaces to bring the surface metal to the desired heat by a single pass of the flame over the surface. When deep penetration is attempted, the llame is often retained on a given area of the metal surface a length of time such that the surface is melted or burned and control of the deptheoff. penetration is thereby lost. Thus,

' now Patent No. 2,480,287, and cao-pending herewith, there is disclosed a method of obtaining deep penetration of a metal surface by effecting intermittent application of the flames to a given area of the metal surface. Heat is thus delivered in separate amounts with time intervening to allow the preceding heat delivery to soak into the metal before the next heat delivery is made. By such procedure, control of the depth of penetration of the'heatlis: had and the smooth metal surface is preserved. Also, apparatus is disclosed in my application for carrying out the method by which the Oxy-acetylene torch which projects the heating flames upon the metal surface is given a sweeping motion as the torch is advanced over the metal surface. The resultant eiect is a long forward sweeping stroke and'a short rearward sweeping stroke. A given area on the surface itt f with the different orifice rows.

is kept stationary on the advancing wheeled carriagefwhile the heating gas for the flames is introduced consecutively into spaced rows of orifices within the' torch-tip. The flames are applied to the metal surface in consecutive order while relative movement is effected between the torch tip and the metal surface. A rotatable valveelement is provided in the torch tip for controlling the iiow of gas to the different rows of orifices. The valve element extends out of one end ofthe nozzletip and is either rotated or oscillated, as the iiame pattern may require, by a motor and reduction gear arrangement on the carrier. The valve element has a recess always containing the mixed gases which registers The recess can be of such width to span only one row at a time. as in .one form oi the invention, or several rows. as in.v another form of the invention.

For a better understanding of the invention.

" reference may be had to the following detailed is thus supplied with heat intermittently or with The disadvantage with this apparatus is that, because of the difference in theflengths of the stroke, uneven heating will result, thereby limiting the use of the apparatus. Furtherf with this apparatus, the

flame pattern cannot be readily changed.

It is one objectofthepresent invention to! provide a method and apparatus for intermit tentlyv applying heat to a metal siuface wherein more even heating of the surface areas will be obtained.

It is another object of the present invention.

an apparatus for intermittently applying heat-- treating flames wherein the torch projecting these dames remains stationary and need not be bodily moved while it is advanced over the metal surface.

According to the present invention, the torch sectionof a torch tip having a valve element -with a spiral recess.

view of the apparatus shown in Fie. 2;4

Fig. t is a perspective view of the torch tip l' looking lup from its bottom and with a section taken in a vertical piane` to show one full orifice ofeach -of four rows and with a valve element recess of-such width asto spaziali of the rows ofsurfaces:

Fig. 5 is' a large elevational view of the same opened up and in section toshow the valve elenient and one full row of orices;

Fig. 6 is a perspective view of therotatable valve element removed from ,the torch tip with drive sprocket attached;

Fig. 7 isapside elevational view, partly in Referring now particularly to Figs. l, 2, 3, there is shown the complete apparatus which comprises a wheeled carriage or Support lil, adapted to be moved over tracks Hf I2'. A metal work-piece i3. having atop-surface It to be heat-treated lies addac'ent'the tracks and beneath a gas torch I5 carried on a bracket I8 extending laterally from carriage body I1. A clamping plate I8 secures the torch to bracket I6 which, upon being released, permits the torch I5 to be vertically adjusted on the bracket.

Torch I5 includes a mixer I9 to which oxygen and acetylene are separately delivered through hoses 2|, 22, a torch tip 23, and a pipe connection 24 coupling the torch tip 23 with the mixer I9. clamp 26 to the torch I5. The torch, if desired, can be designed to be water-cooled.

A rotatable shaft element 21 extends from one end of the torch tip 23 to the other end and hasl a sprocket 28 thereon. A motor 29 and reduction 15 gear 3| drive a sprocket 32 which is, in turn, connected by chain 33 to a sprocket 28. In thismanner, the valve element 21 is rotated.

Torch tip 23 has four parallel rows. a, b, c, d of orifices 34 in tip bottom face 35. These ori- 20 iices 34 extend vertically to valve chamber 31 which contains the rotatable valve element 21., Distributing chambers 38, 39, 40, 4I are respec-- tively provided in rows a, b, c, d to insure good distribution of the mixed gases between the oril ces of a given row. The valve chamber 31 and these distributing chambers may be formed in the tip body by drilling one-large hole and four small holes into the tip body. The small holes are closed with plugs 42, Fig. 5. The rotatable valve 3o element 21 closes oil" the large hole. lThe orifices 34 enter bottom wall 43 of the valve chamber so that outer rows a and d are within 180 degrees from each other.

Valve chamber 31 includes a depressed annular 35 recess 44 which is supplied continually with the heating gases from central passage 45 in threaded inlet portion 46. An orifice portion 34', Fig. 5, opens into annular recess 44 tobleed therefrom sufiicient gas to maintain small non-heating 40 llames at times when recess 41 of the valve element 21 is not in registry with the orifice' rows. Should there be insufficient gas to supply all of the orifices at this time, those orifices which are supplied will serve to provide a pilot ame for 45 the unlighted orifices when the greater supply of gas is delivered. Coupling nut 48, Fig. 2,'on torch pipe connection 24 iits the threaded inlet portion 46 of the torch tip to connect the tip and pipe connection together. i

In the form of the invention shown in Fig. 1, the valve element recess 41 supplies gas to only one row of orifices at a time. As the valve ele-, ment is rotated in the direction of the arrow V48 by chain 33, the orifice rows are supplied with large quantities of the mixed ga'sesuto produce heating llames in the rows in the consecutive order a, b, c, d, a, b, etc. The resulting llame pattern is comparable with the ame pattern shown 6o in the above-mentioned application with the forward stroke omitted. In other words, there is a succession of rearward strokes, and. if the torch remained stationary, intermittent heat would be applied to one section of the work-piece. The 65 relative movement between the carriage and i workpiece during the repeated application of the flames causes the heating of successive and overlapping portions of the surface. l,Sincethe torch is progressed along the metal surface, intermittent heat is applied to the entire path of the torch providing that the number of vrevolutions of the valve element is not reduced to less than two while the torch travelsa distance equal to the distance from row al to rowv-l- If theregolutions 75 f will be a, b, c, d, d, c, b, a, etc., or the same as were so reduced, portions of the metal surface would be untouched by the llames.

If, insteadof rotating the valve element 21 of Fig. 1, the valve element 21 is oscillated, as by a link 53, Fig. 2,in lieu of the chain 33, connected between points 54, 55, on

respective sprockets

32, 28 with the point 55 being of longer arm distance from the center of rotation than point 54 on sprocket 32 to effect only the reciprocation of A quenching nozzle 25 is connected by a lsp'rocket 23, back and forth sweeping motion of the flames is obtained. The flame pattern here that obtained by bodily moving the torch back and forth. This ame pattern does not give as even heat applications as the rotating valve element because the forward stroke travels faster than the rearward stroke. However, for some applications, uneven heating may be desirable.

' When the valve element having a wide recess 41', Figs. 4,. 5, 6, which can span all of the oritice rows at one time, is rotated, a longer consecutive exposure of an area to the flame than when the narrow recessed valve element is rotated, is had. The flame pattern will be a, ab, abc, abcd, a, ab, etc. Still another ame pattern can be obtained by oscillating this same valve element by the link 53.

A In Fig. 7, the valve element 21 has a spiral recess 41". extending once around the valve element and there are no distributing chambersv connecting the torch tip passages in a given row, Mixed gases are continually received by the spiral recess 41" yfrom an annular recess 44 of the valve element 21 and, since the recess 41" extends one full turn about the element the gases` are continuously fed to the torch tip passages.

Consequently, there are always some flames lburning all the time.

thus unnecessary. A further advantage is that the gas flow is more uniform because all of the flames are not extinguished at the same time.

lThe valve element 21 is either rotated by chain 33, Fig. 2, or oscillated by link 53, the same as gv'tlvalve element having the straight recesses It will now be apparent that numerous flame patterns can be obtained with slight alteration of the parts and that this is to bodily reciprocate the torch tip.

- What is claimed is:

1. Apparatus for intermittently and progressively applying heat to a movable carriage, a torch tip mounted thereon having an inlet passage for a combustible gas mixture and a discharge face and a plurality of gas delivery passages orifices in the discharge face arranged in rows spaced apart in the direction in which the heating is to progress, a Vmovable valve element mounted, in said tip having gas passage means adapted upon movement of the valve element to place said inlet passage in communication with saidr-delivery passages in an order such that gas jets for heating llames will be discharged from orifices in said spaced rows in consecutive order, motor driven means mounted on said carriage for operating said valve element, and means for effecting relative movement between the torch tipand the metal surface in the direction in which said rows of orifices are spaced apart.

2. Apparatus for progressively heat-treating a metalfsurface comprising a carriage, a torch tip mounted thereon having an inlet passage for a combustible gas mixture and a discharge face and a plurality of gas delivery passages termi- A separate pilot flame isA eil'ected without havingA a metal surface including I terminating in discharge nating in discharge orices in the discharge face arranged in rows spaced apart in the direction in which the heating is to progress, a movable valve element in said tip having gas passage means adapted upon movement of the valve element to place said inlet passage in communication with said delivery passages in an order such that gas jets for heating flames will be discharged from oriiices in said spaced rows in consecutive order, means for causing movement of the carriage with respect to the metal surface in the direction in which said rows of orices are spaced apart, and means mounted on the carriage for moving said valve element at a speed which is coordinated with the speed of movement of the carriage.

3. Apparatus for progressively heat-treating a metal surface comprising a carriage, a torch tip mounted thereon having an inlet passage for a combustible gas mixture and a discharge face and a plurality of gas delivery passages terminating in discharge orifices in the discharge face arranged in rows spaced apart in the direction in which the heating is to progress, a rotatable valve element mounted in the tip having gas passage means adapted upon movement of the valve element to place said inlet passage in communication with said delivery passages in an order such that gas jets for heating flames will be discharged from orifices in said spaced rows in consecutive order, means for causing movement of the carriage with respect to the metal surface in the direction in which said rows of orifices are spaced apart, and drive means on the carriage for turning the valve element. l

4. Apparatus for heat-treating a metal surface comprising a carriage, a torch tip mounted on the carriage having a discharge face and also having a valve chamber and a plurality of gas passages leading from the valve chamber to the discharge face of the tip, a valve element rotatable in the valve chamber and having an annular depression and also a spiral recess adapted to continually receive gas from said annular depression, and means for turning the valve element to pass heating gases consecutively to saidpasmovement required to heat treat the desired surface area, directing flames upon the metal surface from the orices of the diierent rows consecutively in said direction and repeating said application of the iiames to consecutive portions of the metal surface-throughout the extent of said relative movement, whereby consecutive sweeping motions of the flames are applied to the surface of the metal in a direction in which the heating is to progress.

6. The method of progressively heat-treating a metal surface by iiames which issue from orifices arranged in rows spaced apart in the direction in which the heating is to progress, which comprises effecting relative movement in said direction between the flame orices and the metal surface, and throughout the extent of relative movement required to heat treat the desired surface area, directing flames upon the metal surface from the orices of the dierent rows consecutively in said direction and repeating such application of the ames to successive overlapping portions of the metal surface throughout the extent of said relative movement, whereby consecutive sweeping motions of the ames are applied to the surface of the metal in a direction in which the heating is to progress.

'7. The method of Vprogressively heat-treating a metal surface as deiined in claim 6 in which there are at least two applications of the iiames from each row of oriiices for a relative movement between the orifices and metal surface equal to the distance between the rst and last rows of orifices.

8. The method of progressively heat-treating a metal surface as defined in claim 5 in which the ames from the orifices are moved across a stationary work surface. y

' JOHN J. CROWE.

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

` UNITED STATES PATENTS Number