US2742279A

US2742279A - Machine for heat-treating strip material

Info

Publication number: US2742279A
Application number: US472989A
Authority: US
Inventors: William E Small
Original assignee: Perfect Circle Corp
Current assignee: Perfect Circle Corp
Priority date: 1954-12-03
Filing date: 1954-12-03
Publication date: 1956-04-17
Anticipated expiration: 1973-04-17

Description

April 17, 1956 w. E. SMALL MACHINE FOR HEAT-TREATING STRIP MATERIAL 4 Sheets-Sheet l F'i led Dec. 3, 1954 INVENTOR. Z/dlarwflfiml BY PM sum HM & no

A ril 17, 1956 w. E. SMALL MACHINE FOR HEAT-TREATING STRIP MATERIAL 4 Sheets-Sheet 2 Filed Dec. 5, 1954 April 17, 1956 w. E. SMALL MACHINE FOR HEAT-TREATING STRIP MATERIAL 4 Sheets-Sheet 3 Filed Dec. 3, 1954 INVENTOR.

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April 17, 1956 I w, E, SMALL 2,742,279

MACHINE FOR HEAT-TREATING STRIP MATERIAL 4 Sheets-Sheet 4 Filed Dec. 3, 1954 United States PatentO 1 I MACHINE FOR HEAT-TREATING STRIP MATERIAL William E. Small, Hagerstown, Ind., assignor to Perfect Circle Corporation, Hagerstown, Ind., a corporation of Indiana Application December 3, 1954, Serial No. 472,989

24 Claims. (Cl. 266-25) The invention relates generally to heat treating apparatus and more particularly to a machine for heat treating and shaping partially preformed strip material.

in one form of piston ring assembly utilized in present day internal combustion engines, a combined spacer-expander member is provided to hold a pair of thin steel rails properly spaced from each other and in operative This structure is other. Flanges are provided on the ends of the arms of the U to engage the inner peripheries of the rails. When the ends of such a member are in abutment With each other, the slotting permits circumferential expansion and contraction, and with proper pitch length between the slots when the member is in its free state, the member will exert a predetermined outward force on the, rails when the latter are confined within a cylinder. A piston ring assembly of this type is shown in the Shirk PatentNo. 2,635,022, issued April 14, 1953, and the Estey Patent No. 2,695,825, issued November 30, 1954.

Piston rings have also been made, which have a construction similar in some respects to the spacer-expander member described above, that is, a ring which is transversely slotted to provide for circumferential expansion. It has also been suggested that circular springs for various uses be made in this manner. t

The general object of the invention isto provide a novel machine for heat treating preformed strip material of transversely slotted type. i

Another important object is to provide a novel machine for heat treating strip material of this type and to give the material a' predetermined and uniform pitch length between slots.

A further object is to provide a novel machine of the foregoing character which may be adjusted to provide, within limits, any desired pitch length.

Still another object is toprovide a machine of the foregoing character, which bends the material into a circular form while heated for the heat treating and'which provides for quenching'the material after it is given'the so that it has a permanent set in such shape.

A still further object is to providea machine having the foregoing characteristics and which functions in a continuous manner so that the material may be fed to the machine in a long strip of indefinite length and the treated material comes off the machine in a continuously formed helical coil which may be separated into any desired lengths.

Other objects and advantages of the invention will become apparent from the subsequent detailed description 2,742,219 Patented Apr. 17, 1956 2- taken in conjunction with the accompanying drawings, in which:

Fig. 1 is an enlarged perspective view of a portion of the slotted strip material for which the present machine is adapted; i

Fig. 2 is a perspective view of one embodiment of the invention; 7 e, I Fig. 3 is a .v'erticalfsection'al view taken on the line 3-3 ofFigZ;

Fig. 4; is a sectional view taken on the line 4-4 of Fig. 3;

, Fig. 5 is a fragmentary sectional view taken on the line 5-5 of Fig. 2; r

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 2;

Fig. 7 is a fragmentary rear viewof the'machine; and

Fig. 8 is an enlarged fragmentary sectional view taken on the line'8-8 of Fig. 6. t

As heretofore mentioned, the machine or apparatus dis-j closed herein is adapted for heat treating transversely slotted strip material of the type utilized in certain piston ring assemblies or for piston rings themselves or for other purposes. To illustrate this type of material, 'I have shown in Fig. 1, as anexample, a fragmentary portion of a combined spacer-expander member constituting a' part of a piston ring assembly of the character referred to.

As is apparent'in that figure, the member is formed from an elongated strip of sheet metal, which is transversely slotted alternately from opposite edges of the strip. This slotting results" in providing two rows of segments 10 along the respective edges of the strip, and the segments are connected by web membersll which are spaced from each other and extend transversely of the strip. The strip a groove in a piston with the ends of the member .in abutproper pitch length and after-bending into a circularform ment and the pair of thin steel rails are then plac'ed in the groove in operative relation with the spacer-expander member. When the piston with such a ring assembly is placed in the cylinder of the engine, the rails are compressed from their free state, and the rails in turn cause a compression of the spacer-expander member fromits' free state, the Web members 11 flexing edgewise when the member is compressed. One function of this member is to exert an outward expansive force on the rails to holdthem in contact with the cylinder wall with a predetermined pressure. The expansive force exerted by this member will of course depend upon how much it is compressed from its free state. A member of] this character may be said to have a pitch length which is the length of material between the side of one slot in one edge of the strip to the same side of the next slot-in the same edge, and the member will be composed of a predetermined number offpitch lengths for use in a cylinder of a given diameter. Since the circumferentiallength of the member in its free state is one of the factors determining the force it exerts on the rails when compressedwithin the cylinder, the pitch length for the strip must be carefully controlled in order to give the member; which has a predetermined number of pitch lengths,the correct circumferential length for its free state. The member must also be properly heat treated in order to give it the desired resiliency.

In making members of this character, the slotting and forming into the U-shape are performed on a continuous strip of a length suflicient to make a large number of members andthe strip is then preferably wound on-r eels,

The reels are then taken to the heat treating machine embodying the features of the present invention, and "the strip is unwound from the. reel and fed continuously thrpngh this machine. I

The machine of apparatus disclosed herein is arranged to. heat the material to a desired temperature and to quench the material after such heating to give it the desired resilient characteristics. Preferably heating is effected by electricalinduction means. When the material is soheated, it is in a sufficiently plastic state to permit it to be adjusted to the desired pitch length. V The heated portion of the strip at any instant is of sufficient length to comprise a number of pitch lengths, so the adjustment is made .trated in the drawings, comprises a frame in the form of a box-like cabinet structure indicated generally at 20 andshown in Figs. 1 and 2; Within the cabinet, there is provided a heating means which is tubular in character so that the material heated thereby may be continuously fed therethrough. As shown in Figs. 2 and 5, the heating element preferably is in the form of an induction heater and comprises a quartz tube 21 about which is wrapped a conductor 22 adapted to be connected to a source (not shown) of electrical current of suitable voltage. The heating means extends generally crosswise of the cabinet. The strip of material to be fed into the machine and through the heating means is preferably carried on a reel on the total heated length. The strip comes from the slotting and bending operation with a certain pitch length.

' This may or may not be the desired pitch length for the member. While the desired pitch length may be less than that in the strip when it comes off the reels and the present m achine may be employed to slightly decrease the pitch length, more accurate results and more satisfactory operation can be obtained 'if the pitch length controlled since the drag due to unwinding the strip from the reel would vary and the strip would be variably stretched. To avoid this difficulty, a pair of feeding means is employed, one at the inlet end of the heating means and. one at the discharge end. Each feeding means is provided with a toothed roll'with the teeth engaging in the slots of the material to effect a positive feedv thereof. The two toothed rolls are rotated at the same rate so that the length of material between them is thusheld constant and the pitch length is thusmaintainedconstant.

Since the material on the reel has a pitch length slightly less than desired, the length. of the material between the two-toothed rolls, which includes the heated portion, must be stretched, To this end, one of the feeding means is adjustable. relative to the other to adjust the length of the material therebetween and thus givethe material a predetermined pitch length. Thus, one feeding, means may be -shifted. relative to-the other to adjust the distance therebetween. to adjust the, length oft-he material between the two toothed rolls. The same effectmay be obtained by rotating one'of the toothed rolls; slightly more or-less than the other toothedroll. Thus, by imposing a slight counter rotation momentarily on the-trollat the in'let end of the heating means, the number of pitch lengths. between the two rolls will be slightly decreased and the material will thereby be stretched. In the present machine, the feeding means at the inlet end of the heating is shiftably mounted so that the distance thereof from the other feeding means can be adjusted, and this feeding means is so constructed that such adjustment also causes slight rota- 19 at the leftside of the machine as illustrated in Fig. 2, and the material enters the cabinet 20 through a guide tube 23 extending through an enlarged aperture 24 in the left wall of the cabinet and carried by a bracket 25 mounted on the exterior surface of the cabinet wall.

Because the material being treated is quite flexible and becomes quite plastic when heated, a single feeding means which would draw the material through the tubularheating means would be impractical because of the variable drag on the material in unwinding it from the reel. As generally discussed above, the pitch length of the material has to be carefully controlled. For these reasons, a pair of feeding means are provided, one located at the inlet end of the heating means and indicated generally at 26 and the other located at the discharge end of the heating means and indicated generally at 27.

Both feeding means 26 and 27 are adapted to feed the material at the same rateso that the length of the material between the'two feeding means, which includes the i heated portion of the material, will be held constant. The

stretch the material, while heated, to the desired pitch length. In order that the pitch length may be accurately controlled, one of the feeding means, in this instance the feeding means 26, is'mounted for adjustment relative to V the other feeding means 27.

In order that the two feeding means may feed the material at the same rate, a common drive means is provided' therefor; Thus in the present instance, a motor 30 (see Fig. 7) is mounted within the cabinet 20 and is provided with a belt drive 31 connecting with a shaft 32 The feeding means 26 includes a housing 34 (see Figs.

. 2, 3, 4' and 7-) mounted on a bracket 35 which is pivotally material is permanently set. The material is then loosely wound in a helix a-nd a 'helical'coil-of the material may be removed from the machine by breaking the strip at the desired point, the material being 'britt'le after cooling;

The preferred embodiment of the invention, as illussupported at its lower end by a rod 36 carried by the front and rear walls of the cabinet 20. The shaft 33 extends into the housing 34 at the rear end thereof and is journalled in bushings 37 mounted within the housing. Within the housing, a worm 40- is rigidly mounted on the shaft 33 and meshes with a worm wheel 41. The worm wheel 41 is mounted on the rear end of a stub shaft 42 journalled in bearings in the housing34. The stub shaft 42'at its front end carries a toothed roll 43' (see Fig. 3) which engages the strip of material with the teeth thereof entering the slots in the material to positively .feed the strip. The method roll 43 is preferably placed between two flange members'44 mounted on the shaft 42 and the toothed roll 43 and theflan-ge members'ml are clamped thereon by means of a nut 45 threaded onthe end of the stub shaft 42.

Cooperating with the toothed roll 43 is an idler roll 46-having a plain cylindrical periphery and mounted on a bearing 47 carried by a stud 50. The =stud- 50 is-secured in an arm 51 extending downwardly from and adapted such, adjustment.

positively feed the strip of material to the heating means and draws the material through the guide tube 23. The left'end of the quartz tube 21 is preferably supported in an opening 52 formed in'a, portion of the bracket 35, as shown in Fig. 2.." I

The feeding means 27' at the right .or discharge end of ing means. The toothed roll 57 is adapted to be clamped on the shaft 56 between a pair of flange members 60, and a nut 61 is threaded on the end of the shaft 56 to hold the toothed roll 57 and flange member 60 in fixed relation on the 'shaft.

The toothed-roll 57 cooperates with a forming roll 62,

which will .be described more fully hereinafter, to draw the material from the heating means at the same rate that the feeding means 26 feeds the material into the feeding means. The forming roll 62 is journalled on bearings 63 mounted ona tube 64 clamped in a pair of arms 65, one at the front end of the housing 53 adjacent the toothed'roll 57 and the other at the rear end of the housing. The arm 65 at the front end of the housing is clamped about the housing itself while the arm 65 at the rear end of the housing is clamped on a cover member 66 forming a partof the housing. With the foregoing structure, it will be apparent that both of the toothed rolls 43 and 57 are rotated at the same rate and thus feed the material at the samerate. 1 The portion of the materialbetween the two toothed rolls, which includes the heated portion of the material, will thus-be held to a-constant length.

As heretofore mentioned, thematerial fed to the present machine may vary in the pitch length thereof and preferably ismade slightly less than that desired. The two feeding means which include the two toothed rolls 43 and 57, while holding the portion of the strip between them to l a'fixed length, can befrelatively adjusted to adjust suchtation to decrease the amount of material between the two feeding means. In the present'instance both forms of adjustment are simultaneously effected.

For this purpose, the bracket 35 is pivotally supported and may be swung on its pivot rod 36. To effect the swinging adjustment thereof, a nut 70 (see Figs. 2, 3 and 7) is pivoted at opposite sides thereof in a portion of the bracket 35 and an offset plate 71 secured to the bracket 35. Threaded in the nut 70 is arod 72 which extends to the right within the cabinet 20 through the wall thereof and is fixed against endwise movement and provided with a knob 73 onits outer end. By rotating the knob 73, the

nut 70'will be adjusted along the" rod 72 to swingthe I bracket 35. When the bracket 35 is swung toward the left of the. machine, the distance' between the two feeding means 26 and 27 is thus increased and, since the toothed rolls thereof engage positively in slots in the material, the material therebetween will be stretched to the extent of Adjpstrnent of the p' ch length of the material is also At its forward end,- the stub shaft.

t '6 I effected by inducing a slight counter rotation to. the toothed roll 43. To this end, the worm 40 is'fixed onthe shaft 33 and is permittedto have a slight movement relative to the housing when the bracket 35' is swung. Thus as shown in Fig. 4, a small space 74 is provided between the worm 40 and thebushing 37. When the bracket 35 is swung towards the left; the housing :34 also moves toward the left and carries the worm wheel 41 along with it. 'Since the worm 40 is fixed against endwise movement, a slight rolling movementof the worm wheel 41-is thereby effected along the worm 40. Such rolling movement of the worm. wheel 41 is transmitted to. the'toothed roll 43 because they are both mountedon the same shaft, and the toothed roll 43 is thereforeiadjusted rotatively in' a direction counter toxits normal rotation in. feeding the material. The counter rotation of the toothed roll 43 reduces the number of pitch lengths of the material between it and the other toothed roll 57 so that such rotative adjustment also effects stretching of the heated portion of the material. Thus adjustment of the feedingmeans 26 by the knob 73 both increases the spacingbetween the two feeding means and decreases the number of pitch lengths therebetweento effect the desired amount of stretching of the material. When the feeding means 26 is suitably adjusted, it is held in its adjusted position and the material continues to .be fed thereby and the two feeding means thus holdthe pitch length of the material to that desired. t

The present machine also includes means for imparting a circular form to the material, the toothed roll 57 and the forming roll 62 performing this function. The forming roll 62, being carried by the arms 65 which are clamped about the housing 53, are adjustable about the axis of the toothed roll 57. To effect the circular forming of the material, the forming roll 62 is positioned sothat the heated materialas it leaves the quartz tube 21 of the heating means extends generally tangential to the forming roll 62,- and the toothed roll 57 is so positioned that it causes the hotmaterial to wrap over an arcuateportion of the forming roll 62. Thematerial is thus bent into a circular form. The toothed roll 57 is therefore-positioned to engage the material slightly beyond the point of tangency, as illustrated in Fig. 8.- The forming roll.62;.is driven at the same rate as the toothed roll 57 by means of a gear mounted for rotation with-the toothed roll57 and meshing with a gear.81 secured to the forming roll '62, the gears 80 and.81 being of the same-size. In order portion 84 (see Fig.6). adjustably mounted on the tube 64 which supports the forming roll 62. Thus when the formingroll 62 is adjustedabout'the axis of the toothed roll 57, the bracket supporting the quartz tube of the heating means may also besuit ably adjusted about the axis of the forming roll 62. A strap 88 secured to the plate 83 and to the cabinet isprovided to hold theyplate 83 in its adjusted position. i

The material, after it has been stretched to the desired pitch leng'th andafter it has been given the circular form by being wrapped partially on the forming roll 62, is then quenched to set it permanently in such condition. To this end a nozzle 85 (see Figs.,2 and 8) is provided and is connected to a. means (not shown) for supplying coolant thereto. The nozzle 85 directs thecoolant on to the material at substantially the point where the material enters the bite'between the toothed roll 57 and the forming roll 62 and after the'materialhas been given its circular form by being wrapped on the forming roll. The material is thus permanently'set in the desired condition. To prevent a pool of coolant from building up in front offthe bite 'betwee'n'the toothed roll 57 and the forming roll 62, which would tend to cool the material before it is given this circular form,'the flange members 60 adjacent on the: forming roll.

Wardly' along the material Where it would prematurely chillthe material or run into the tubev21.

To facilitate handling of .thernateri'ahafter it leaves the present machine, it is preferably formed into elongated helical: coils. r 'Tothis end a carn plate 86 (see Figs'Z and 5). is secured: to the block 82i'which'supports the quartz tube 21 andembraces the forming. roll 62 immediately in front of theposition wherethe toothed roll 57 and the formi-ngroll 62 engage the material; Onitsfree end, the

cam: plate 86' is provided with alip 87, bent out of the plane of the plate so that the: strip of material after being formedis forced longitudinally of: the forming roll- 62.

, Since the forming roll 62- is rotatably driven, the material coming off the machine willsbeformed into a helical coil To support: such coil, the forming roll 62is elongated by being provided with an extension 90; To prevent the coil of material from binding on-the extens'ion- 90, the latter is of reduced diameter relativetothe forming'portion of the forming roll, and the forming roll is'tapered as at 9L to the diameter of the extension 90.

The material as it comes from themachine is quite brittle because of the heating andsubsequent quenching. Thus when a helical coil of desired length of thematerial is formed on the extension 90, the inner end may be readily broken by merely snapping the material and the coil may be removed endwise from the extension 90- to permit another coil to be formed thereon.

From the foregoing description, it will be apparent that I have provided a'novel machine for heat-treating preformed strip material of the transversely slottedtype. :By adjustment'of the feeding means 26, the'heated portion of the strip as it passes through the machine may be given a predetermined and uniform pitch length be tween'slots. As the material. emerges from the heating means,itis bent into a circular form-andthen quenched so that the material is permanently setwith the proper heating means for heating'the material as it is fed there through, a pair of feeding 'means'lo'cated' at the respec tive ends of said heatingfmean's for feeding the. material into and Withdrawing the material from said heating means to hold the heated portion of the material within s'aidlheatin'g'mcans to a predetermined length, andmeans for bending the material into circular'form while still hot after passing through saidheating means.

' '2. A heat treating machine for slotted strip material of the character described, comprisingtub'ular heating means for heating the material as it is fed' therethrougb, a pair of feedingmeans'locat'e'd' at there'spe'ctive' ends of said "heating means for feeding" the material-into and withdrawing the material from said heating, means to hold the heated portion of the material within. said heating means to apredetermined l ength,.means cooperating withv the feeding means at the discharge end'of said heating means for bending the material intocircular form while still hotfrom passing through said heating means, and means for directing coolant on the material after being-bent for giving the material a-permane'rit set in its circular form and of predetermined;unit length5 1 3'. A heat treating machine for slotted strip material of the character described, comprising. tubular heating means for heating the material'as' it is fed 'therethrough, and a pair of feeding means located at therespective ends of said heating means for feeding the material into and withdrawing the material from said heating means,' said pair of feeding means operating atthe same rate to hold the heated portion of the material to a predetermined length.

4. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as it is fed -therethrough, and apair of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing the material from said heating means, each of said feeding means including *a too'thed roll with the teeth adapted to enter the slots in the material to positively feed the material, and means for'driving the toothed rolls of both feeding means at the same rate to hold the heated portion of the material to a predetermined length:

5. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as it is fed -the'rethrough', and a pair of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing the material from said 'heating means at the same rate to hold the heated portion of the material to a predetermined length, and means for adjusting the spacing of one feeding means from the other to adjust the length to which the heated portion is held.

'6. A heat treating machine for "slotted strip material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, and a pair of feedingmeans located at the respective ends of said heating means for feeding the material into and withdrawingthej material from said heating means, a shiftable bracket'supp'o'rting one of said feeding: means, adjustable means for shifting said bracket for adjusting the spacing between said feeding means, and means for driving both of said feeding means at thesame rate to hold the heated portion ofthe material to a length determined by said adjusting means.

7. A heat treating machine for slottedstrip material of the character described,comprisingtubular heating means for heatingthe material as it is 'fed therethrough, and a pair of feeding meanslocated at the respective ends of said heating means for feeding the material into and withdrawing the material from said heating means, each of said feeding means including a toothed roll with the teeth adapted to enter the slots in the material to positively feed the material, means for adjusting the spacing. of one toothed roll from the other, and means for driving both of said toothed rolls at the same rate to hold the heated portion of the material to a length determined by .said adjusting means. I V V I 8. A heat treating machine for slotted material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, and a pair of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing the material from said heating means, each of said feeding means including a toothed roll with the teeth adapted to enterthe :slots in the material, means for driving the toothed rolls ofboth feeding. means at the same rate to hold the heated portion of the material to a predetermined length, andmeans rotatively adjusting one ofsaid rolls relative to the other to adjust the length of the heated portion.

9. A heat treating machine for slotted material of the character described, comprising tubularheating means for heating the material as his fedtherethrough, a pair of feedmg means located at the respective end's'of said heating means for feedingthe material intogand Withdrawing the material from said heating means, each of said feeding means including a-too'thed roll withthe V 9 teeth adapted to enter the slots in the material, means for driving the toothed rolls of both feeding means at the samerate to hold the heated portion of the material to a predetermined length, and means for shifting one of of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing the material from said heating means, and means for adjusting one of said feeding means relative to the other to adjust the length to which the heated portion'is held.

11. A heat treating machine for slotted strip material ofthe character described, comprising tubular heating meansfor heating the material as it is fed therethrough, a'pair of feeding means located at the respectiveends of said heating means for feeding the material into and withdrawing the material from said heating means, and means for increasing the spacing of one feeding means from the other to stretch the heated portion of the material to a'predetermined length.

12. A heat treating machine for slotted material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, a pair of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing the material from said heating means, each of said feeding means including a toothed roll with the teeth adapted to enter the slots in the material, means for driving the toothed rolls of both feeding means at the same rate to hold the heated portion of the material to a. predetermined length, and means for shifting one roll away from the other and simultaneously rotatively adjusting said one roll to stretch the heated portion of the material to a predetermined length.

heating means for feeding the material into and withdrawing the material from said heating means, one of said feeding means comprising a toothed roll with the teeth'adapted to engage in the slots in the material, a shiftably mounted housing enclosing a driven shaft having said toothed roll and a worm wheel mounted thereon, a drive shaft extending into said housing in slidable relation therein and having a worm rigidly mounted thereon in mesh with said worm wheel, and means for shifting said housing to adjust the spacing of said toothed roll from the other feeding means and to efiect rolling movement of the worm wheel relative to the worm to rotativelyadjust said-toothed roll to adjust the length of the heated portion of the material, the other feeding comprising a toothed roll, and means connecting said lastmentioned toothed roll to said drive shaft for driving said last-mentioned toothed rollat the same rate as said first-mentioned roll.

14. A heat treating machine, for slotted material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, a pair of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing the material from said heating means, eachof said feeding means including a toothed roll with the teeth adapted to enter the slots in the material, a worm wheel element coaxial with one of said toothed rolls and drivingly connected thereto, a worm element for driving said worm wheel element, means for driving said worm element and the other toothedroll, and means for adjusting one of said elements longitudinally of the worm 10 element to rotatively adjust said one toothed roll relative to the other toothed roll to adjust the length of the heated portion of the material.

15. A heat treating machine for slotted material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, a pair of feeding means located at the respective ends of said heating means for feeding the material into and withdrawing'the material from said heating means, each of said feeding means including a toothed roll with the teeth adapted to enter the slots in the material, a worm wheel coaxial with one of said toothed rolls and drivingly connected thereto, a worm for driving said worm wheel, means for driving said worm and the other toothed roll, a support for said one toothed roll and said worm wheel, and means for shifting said support to roll said worm wheel along said worm and thereby rotatively adjust said one toothed roll to adjust the length of the heated portion of the material.

16. A heat treating machine for slotted stripmaterial of the character described, comprising tubular heating means for heating the material as it is fed therethrough, and feeding means located at the discharge end of said heating means comprising a feeding roll and a forming roll holding the material therebetween to draw it from said heating means, said feeding roll being positioned to bend the material on the curvature of the forming roll while the material is still heated from the heating means.

17. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, and feeding means located at the discharge end of said heating means comprising a feeding roll and a forming roll holding the material therebetween to draw it from said heating means, said feeding roll being located at a point beyond the point Where the material first contacts said forming roll and holding the material against the forming roll to bend it to the curvature ofthe forming roll while the material is still hot.

18. A heat treating machine forslotted strip material of the character described, comprising tubular heating means for heating the material as it is fed therethrough,

and feeding means located at the discharge end of said heating means comprising a feeding roll and a forming roll holding the material therebetween to draw it from said heating means, said forming roll being positioned so that the path of travel of the material through the heating means is generally tangent to the forming roll, said feeding roll being located beyond the point of tangency to bend the material to the curvature of the forming roll while still hot.

19. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as it is fed therethrough,

and feeding means located at the discharge end of said and feeding means located at the discharge end of said heating means comprising a feeding roll and a forming roll holding the material therebetween to draw it from said heating means, said feeding roll being positioned to Wrap the material around an arcuate portion of the forming roll to bend the material while hot, and means for directing a stream of coolant on the material after being bent, said heating means slanting downwardly toward said forming 1'1 rollitoprevent the coolant from mnning along the material toward the heating means. i

21. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as it is lied therethrough, and feeding means located at the discharge end of said heating means comprising a feeding roll and a forming roll holding the material th5I6btW66l],'tO draw it from said heating means, said feeding. roll being positioned to hold the material against the forming roll for an arcuate portion of the latter, said forming roll being supported for swinging movement about the axis of said feedingroll for adjusting the length of said arcuate portion, and means'for driving both of said rolls at the same speed.

22. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as it is fed therethrough, and feeding means located at the discharge end of said heating means comprising a feeding roll and a' forming roll holding the material therebetween to draw it from said heating means,' saidr feeding roll being positioned to .hold the material wrapped against the forming roll for an arcuateportion of the latter to form the material into a coil, and means for camming' the material into a helix after it passes said feeding roll, said forming roll being elongated toreceive the helix of material.

23. A heat treating machine for slotted strip material of the character described, comprising tubular heating means for heating the material as .it is fed therethrough, and feeding means located: at the discharge end-of said heating means" comprising a feeding roll and to. form ing roll holding the material therebetween to draw it from said heating means, said feeding roll being positioned to hold the material wrapped against the forming roll for an arcuate portion of the latter to form the material into a coil, and means for camming the ma terial itno a helix after it passes said feeding roll, said forming roll being elongated and of reduced diameter beyond the forming portion thereof to loosely receive and support the helix of material.

' 24. A heat'treating machine for slotted strip material of the character described; comprising tubular heating means for heating the material as it is fed therethrough, and feedingmeans located at the discharge end of said heating means comprising a feeding roll and a forming,

'roil for holding the material therebetween to drawit from said heating means, said feeding roll being positioned to hold the material against the forming roll for anarcnate portion of the latter, a support for said -form ing roll mounted for swinging movement about the axisof said feeding roll for adjusting the lengthof said arcuate portion and a bracket on said support carrying theadjacent end of said heating means and swingable with said support to adjust the end of said heating means to the adjusted position of said forming roll.

No references cited.