US1950623A

US1950623A - Method of and machine for producing spiral fin tubing

Info

Publication number: US1950623A
Application number: US519370A
Authority: US
Inventors: Charles W Owston
Original assignee: McCord Radiator and Manufacturing Co
Current assignee: McCord Radiator and Manufacturing Co
Priority date: 1931-03-02
Filing date: 1931-03-02
Publication date: 1934-03-13
Anticipated expiration: 1951-03-13

Description

Mafch 13, 1934. c. w. OWSTON METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING 6 Sheets-Sheet 1 Filed March 2. 1951 W v M ATTORNEYJ.

March 13, 1934. c. w. owsToN 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING 6 Sheets-Sheet 2 Filed March 2, 1931 INVENTOR. [flaw/E5 W. [7W5/27/7 aw Fm ATTORNEYJ,

March 13, 1934. c. WIOWSTON 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING Filed March 2. 1931 s Sheets-Shef 3 &

INVENTOR.

1755/ /55 fk Z7W5/L/7/7 Q M,4AM,M 54....

ATTORNEYJ'.

March 13, 1934. c, w OWSTON 1,950,623

'METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING Filed March 2, 1931 6 Sheets-Sheet 4 INVENTOR. [bar/E5 W Z7W5/0/7 ATTORNEYS.

March 13, 1934.

' c. w. OWSTON 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING Filed March 2, 1931 6 Sheets-Sheet 5 Mum I .Nk/ RM INVENTORV March 13, 19 4, c. OWST'QN 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING I Filed March 2, 1931 6 Sheets-Sheet 6 1 INVENTOR.

TTORNEYS Patented Mar. 13, 1934 UNITED STATES PATENT OFFICE METHOD OF AND MACHINE FOR PRODUC- iNG SPIRAL FIN TUBING Charles W. Owston, Detroit, Mich., assignor to McCord Radiator & Mfg. 00., Detroit, Mich., a

corporation of Maine This invention relates to a method of and machine for producing spiral fin tubing.

One object of my invention is to provide a method and machine whereby the spiral fin material may be applied to the tube without rotating the latter.

Another object of my invention is to provide a machine in which the supply of fin material is rotated asa body about the axis of the tube, thereby permitting the tube to be fed through the machine without being revolved.

Another object of myinvention is to have the tube fed longitudinally through the machine through the center'of the fin material supply, thereby permitting the fin material to be drawn from the outer or inner circumference of the supply in the application of the fin material to the tube.

A further object of my invention is to provide a high-speed machine whereby the fin material may be wound on the tube at a greater speed than heretofore, thereby increasing the rate of production of the machine.

The invention consists further in the matters hereinafter described and claimed.

In the accompanying drawings Fig. 1 is a side view, with parts in section, of my improved machine;

Fig. 2 is a rear end view of the machine, with parts in section and parts broken away for the sake of illustration;

Fig. 3 is a top plan view of the machine with parts in section;

Fig. 4 is a front end view of the machine with parts broken away for illustrative purposes;

Fig. 5 is a perspective view of certain of the bearing blocks;

Fig. 6, is a front view of the fin guide;

Fig. 7 is a sectional view taken on line 7-7 of Fig. 6;

Fig. 8 is a similar view taken on line 8-8 of Fig. 6;

Fig. 9 is a perspective view illustrating the direction of movements of the gear assembly to be hereinafter described;

Fig. 10 is a view similar to Fig. 4 illustrating the fin strip material being taken from the inner circumference of the reel;

Fig. 11 is an elevational view illustrating the releasable locking device for the removable cover plate to be hereinafter described; I

Figs. 12 and 13 are sectional views taken on lines 12-12 and 13- -13, respectively, of Fig. 11; and

Fig. 14 illustrates the manner in which the fin strip material is squeezed as it is applied to the tube to so change the cross-sectional shape of the fin strip that it may wind in spiral form about the tube.

In the drawings, 1 indicates the base of the machine, preferably in the form of a table having a top plate 2 and a number of depending

legs

3, 3.

Arranged on the top plate 2 at the rear end of the machine is a tube feeding and straightening assembly 4 having a plurality of upright laterally spaced

standards

5, 5 arranged on opposite sides of the machine and providing vertical guides for

bearing blocks

6, 6, in which are journaled

cross shafts

7, 7, as shown in Figs. 1 and 3. Each shaft is provided with a roll 8 having a peripheral groove 9 of a shape to accommodate a tube 10, which is fed through the machine, and on which tube-the fin material is spirally wound, as will be hereinafter described.

' Certain of the rolls 8, and thus their shafts '7, are arranged in vertical sets along the length of the tube feed, so that a number of the rolls engage the upper and lower surfaces, respectively, of the tube 10, as shown in Fig. 1. Thus, the tube 10 is supported in its passage through the roll assembly, and with springs associated with the blocks of the rolls, sufficient tension may be placed on the rolls to force them into contact with the tube and thus serve to straighten as well as feed the tube through the machine in the rotation of the rolls in a direction required for the feed. The rolls of the vertical set are power-driven for this purpose. The form of drive, as shown in the drawings; is as follows: Sprocket or

chain wheels

12, 12, are fixed to the cross shafts 7 of the lower rolls. These wheels are connected by suitable power transmitting

chains

13, 13, so that the power fur nished to one of the shafts will rotate the other". In the drawings, I have shown the power fur-- nished to the lowermost shaft 7, at the inner end of the roll assembly. This shaft is extended beyond one side of the base or bed of the machine, and is there provided with a sprocket or chain wheel 14, which by a chain or equivalent element 15 is connected -with a sprocket or chain wheel 16 on a shaft 1'! mounted in the base of the machine, as shown in Fig. 2. A worm gear 18 is fixed to the shaft 17 within the base of the machine, and is in mesh with a worm 19 on a shaft 20, which is arranged to extend lengthwise of the machine, and has a sprocketor chain wheel 21 engaging a chain 22,

which leads to a chain wheel 23 fixed on a revoluble drum 24 at the front end of the machine to actuate the fin applying mechanism. Power is furnished to shaft 20 from a suitable source, as for instance, a line shaft or an electric motor through drive chain 25 and chain wheel 26 on shaft 20, as shown in Figs. 1 and 2. There may be a suitable clutch device 2'7 on shaft 20 in association with wheel 26, whereby the power tothe machine may be cut in and cut off, as desired.

Drum 24 is mounted in anti-friction bearings 28, 29, supported in

upright standards

30, 30, on the upper side of the base 1 of the machine at the opposite ends of the drum, as shown in- Fig. 1.

The shaft 7 of the upper roll of each set of rolls in the feeding mechanism is rotated by the lower shaft of the set by being connected therewith through

intermeshing gears

7, 7 as shown in Fig. 2. The bearing blocks 6 for the various shafts, as shown in Fig. 5, are provided with vertical grooves 6 6 on opposite sides thereof to slidably engage the associated standards 5. The springs 11 for each set of rolls are preferably interposed between the blocks for such rolls. The blocks have suitable recesses 6 6 to accommodate the springs as shown in the drawings. The springs for the idle rolls bear at their upper ends against the bearing blocks for such rolls and at their lower ends The shaft 20 is journaled in a hanger 31,'

depending from the under side of the top plate 2 of the machine as shown in Figs. 1 and 2. The top plate 2 is provided between the

standards

30, 30, with an opening 32, so that the chain 22 may extend upward through the plate to engage the wheel 23 on the drum 24, as shown in Fig. 3.

A tubular guide 33 is disposed axially of the drum 24, and receives the tube 10 from the feed roll assembly 4 in the operation of the machine. The drum 24 is provided at its front end with an enlarged circular disk-like head 34, which r0; tates with the drum in the turning of the same through the chain 22. The head 34 is provided with a centrally disposed cavity 35, at which the adjacent end of the guide 33 terminates as shown in Fig. 1 to form a surface against which the fin strip material 36 is pressed in the applying of the material edgewise about the exterior of the tube 10. A revoluble disk 3'7 is associated with this end of the guide 33, and serves to force the fin strip against the guide in the application of the strip to the tube. It is essential that the guide 33 and the disk 37 be revolved in a direction to feed the fin strip material onto the tube. This is accomplished in the following manner:

A shaft 38 is journaled in the drum 24 at one side of and in parallel relation. to the guide 33. The disk 37 is secured to the end of the shaft at the cavity 35. The other end of the shaft is provided with a spur gear 39, which meshes with a similar gear 40 fixed to the guide 33. Gear 40 meshes with a gear 41 loosely mounted on a stud shaft 42 carried by the drum 24. These gears are at the inner end of the drum and are located in a cap-shaped housing 43 which is secured to the adjacent standard 30. The housing 43 is thus stationary and supports a bushing 44, which is locked-against rotation by a nut 45. Bushing 44 is provided with gear edge of the recess 49.

teeth 46 arranged about the same, with which teeth meshes a gear 47 loosely mounted on stud shaft 42. Gears 41 and 47 are preferably integrally connected, being made in spool form. As shown in Fig. 9, when the drum 24 is revolved in the direction of the arrow a, gear 47 is rolled about the stationary gear 46, and gear 47 is turned in the direction of the arrow indicated in the figure. Gear 41 is turned by gear 47, and rotates gear 40 in a reverse direction as indicated in Fig. 9, thus revolving or turning guide 33 in the same direction as gear 40. The turning of gear 40 turns gear 39 in the direction indicated by the arrow, and through the shaft 38 rotates disk 37 as indicated in Fig. 9, thus causing the fin material fed between disk 37 and guide 33 to be positively drawn from the fin stock and onto the exterior of the tube 10. This is accomplished by having disk 37 set sufiiciently close to guide 33 to frictionally grip the strip between them.

The fin stock is applied to the machine in the form of a fiat reel or coil 48 as shown in Figs. 2 and 4. This coil is located in an annular recess or cavity 49 provided in the front face of the disk or head 34 on the outer side of the same, with a cover plate 50 over the stock material, as shown. The inner circum ference of the coil surrounds an annular flange 51 provided on the head 34 at the base or inner To enable the coil of fin stock material to revolve bodily with respect to the head 34, and thus permit a ready and easy drawing of the fin material from the reel, I provide movable supports 52 in the flange 51 for the inner edge of the coil as shown in Fig. 4. These supports are preferably in the form of rollers located in recesses 53 in the flange 51, the parts being so arranged that the rollers extend slightly beyond the outer periphery of the flange, so as to provide a support for the reel. The axis pins 54 for the rollers 52 are preferably in the form of screws threaded in the head 34 on the rear sides of the rollers, as shown in Fig. 8. The outer ends of these pins extend through a ring 55 which by the screws is clamped against the outer side of the flange 51 over the outer ends of the recesses 53 to provide a cover therefor. The inner edge of the cover plate 50 overlaps and is secured to a ring 56 by rivets 57, and said ring is detachably secured to the flange 51 by fastening means to be presently described. The ring 56 has a recess on its inner side to accommodate the ring 55, as shown in Fig. 7.

The flange 51 is cut away at one point in its circumference, as at 59, through which the fin material 36 passes on being drawn from one of the circumferences of the reel 48, as shown in Figs. 4 and 10. In Fig. 4, the fin material is drawn from the outer circumference of the reel over a roller 60'mounted on the head 34 beyond the outer edge of the reel and in radial alinement with the slot 59. The cover plate 50 is cut away, radially, in line with this slot so that the fin material may be drawn across the front side of the reel to the guide assembly in the cavity 35. To wind the strip material on the tube, it is necessary that the strip be presented to the tube in edgewise relation thereto, as shown in Fig. 6. This makes it necessary therefore that the strip material prior to presentation to the tube be turned into edgewise relation thereto at some point between the tube and the roller 60-. This is accomplished by twisting the strip into edgewise relation to the tube just after it leaves the roll 60 and passing the strip-so disposed through a guide channel or way 61 in the cavity immediately in advance of the point where the strip is presented to the tube for spiral winding thereon. The channel 61 is preferably in the form of a longitudinal groove provided in a metal block or bar 62, which is clamped against the bottom face of the cavity by cross member 63 through the medium of bolts or screws 64, 64, at the opposite ends of the bar as shown in Figs. 6 and 8. The head 34 is preferably in the form of a casing of some light material, so as to reduce its weight, and also reduce as much as possible the effect of the centrifugal force set up in the rotation of the head, and to provide a wearing surface for the fin strip material, as it is fed to the tube 10, I provide a hard metalwear strip 65 secured to the head in the cavity opposite the guide strip 62 by a screw 66, as shown in Fig. 8.

The cover plate 50 is detachably secured to the head 34 in the following manner: As shown in Fig. 11 the ring 56 is provided with a pair of diametrically disposed key slots 6'7, 68, extending through the ring in circumferential di- -rection. Screws 69, '70 extend through the respective slots, and are anchored at their inner of the cover plate. The screw 69 extends outward beyond the ring 56, and provides a slida- -ble support for a sleeve '71, within which is a coil spring '72, bearing at its outer end against the under side of the head of the screw, and at its inner end against the associated end of the sleeve, so as to normally urge the sleeve inward. The larger end of the slot 6'7 is slightly larger than the sleeve '71, so that when the ring has been turned to register the sleeve with the larger end of the slot, the sleeve will be forced by its spring into the slot, and thus permit removal of the ring over the sleeve. The screw '70 for the slot 68 has its head spaced slightly outward from the outer face of the ring 56, and. cooperates with a spring plate 73 secured to the outer surface of the ring as shown in Fig. 11. This plate is designed to enter beneath the head of the screw '70 to aid inholding the ring 56 and its cover on the head 34. The plate '73 is providedwith a slot or notch '74 to accommodate the'shank of the screw '70 in the turning of the ring 56 'into and out of released position. The enlarged end of the slot 68 is large enough to permit passage of the head of the screw '70 therethrough when the ring 56 has been turned to release position. At such time, the spring 68 are reversely arranged, so that when the ring 56 is turned in one direction the enlarged ends of the slots will be brought into register with the head'of the screw '70, and the sleeve '71, respectively, whereas when the ring is turned in the opposite direction, the smaller portions of the slots will be brought opposite the screw and sleeve, respectively. In this position, the ring and its cover are fastened to the head, the coil spring '72 of the sleeve serving to force the sleeve against the outer side of the ring across the narrow portion ofthe slot 67, while the spring plate '73 by engagement under the head of the screw '70 forces the ring against the head 34. To release the cover plate 50, the

. sleeve '71 is .drawn outward against the tension of the spring '72, whereupon the ring 56 may be turned to register the large portions of the slots with the sleeve 71 and head of the screw '70, respectively.

The machine shown and described operates as follows:

To load the machine, the cover plate v is taken off. A reel or coil of fin-strip material is then placed in the cavity 49, whereupon the cover plate is re-applied, and fastened in place. The outer end portion of the fin-strip material on the outer circumference of the reel is then drawn over the roller 60, ,twisted and inserted through the guideway' 61, whereupon the strip is drawn partly round the tube 10 which has been projected beyond the guide 33. The strip is then tacked, as by solder, to the outer surface of the tube 10, whereupon the machine is set in motion, and the fin strip rapidly applied on the outside of the tube 10 in the form of a sprial, as the head revolves about the axis of 'the tube, and the tube without rotation is fed endwise or longitudinally through the machine beyond the head 34. The fin strip is squeezed sumciently or shaped as it passes between the guide 33 and the disk 37 to so thin the outer edge portion of the strip that it will readily wind on the tube and adjust its outer circumference to the increased length provided by winding the strip edgewise on the tube.

To squeeze the strip to so change its crosssectional shape that the strip may wind in spiral form about the tube in the operation of the machine, the rear face a: of the disk 3'7, is beveled or inclined outward while the opposed end surface y of the guide 33 is straight and substantially normal to the axis of the tube or guide as clearly shown in Fig. 14. This provides a triangular-like throat with the apex at the outer end of the throat so as to change the 1 direction to draw the strip through the throat,

the squeezing or reducing action on the strip is a rolling or rotative one. This not only aids in drawingthe strip from the supply coil about the tube, but also aids in causing the strip to wind in spiral form about the tube or adjacent core. Obviously, this squeezing or reducing action on .the opposite sides of the strip, thins the outeredge portion of the strip so that it will wind in spiral form on the tube as the head 3'7 is revolved about the axis of the tube as the tube is fed longitudinally through the head.

The machine is continued in operation until the supply of fin material is practically exhausted from the reel, whereupon a new reel is applied, and its outer end either overlapped and brazed to the outwardly extending end of the previous reel, or run onto the tube and tacked thereto as before described. After the connection has been made, the machine is set in operation and the Winding continues with the fin in the form of a continuous spiral about the tube. In practice, the tubes run through the machine are of predetermined lengths. With the machine being continuous in its operation, the length of the'tube does not require that the machine be stopped, and the fin-strip materialbe severed and then connected with the next tube, because the tubes as they are fed into the machine may ends through the medium of a suitable clampfixture ('75, Fig. 3), which may be inserted in the bore of the tube and be tightened to connect two tubes together by rotating one with respect to the other after the clamp has been connected with one of them. This, in effect, produces a continuous length of tubing and the fin material may be wound over the joint between the several tube lengths. The tubing with the-fin material Wound thereon is fed out of the front end of the machine into a suitable V-shaped trough (not shown) supported at a proper height above the fioor to receive the finished product. The operator to separate the tube lengths need only sever the fin material where it extends over the joints between the tube sections. In this way, a supply of fin material, as carried by the machine, may have a lineal length sufiiicient to take care of the several lengths of tubing, without stopping and starting the machine at the beginning and end of each length of tube section. It is only necessary to stop the machine when the coil of fin material becomes exhausted. This stopping is only momentary because the machine is so constructed that a new supply may be readily and quickly applied.

Instead of taking the fin strip material 36 from the outer circumference of the reel 48, as shown in Fig. 4, the fin strip material may be taken from the inner circumference of the reel, as shown in Fig. 10. In this case, the fin strip material is led over a roller located in the slot 59 in the flange 51. The strip after passing over the roller is twisted so as to enter the guideway 61 for presentation in edgewise relation to the tube 10. The structure of the machine remains the same as before, the only difference being the location of the guide roll for the fin strip as it passes from the reel to the guideway 61. The fact that it is possibly easier to make a connection between the fin-strip material wound on the tube and the outer end of a new reel, makes it preferable to take the feed from the outer circumference of the supply, asthe inside of the reel running out may be welded or attached with much more ease to the outside end of the new reel.

The machine of my invention is simple in construction, and is eflicient in operation. The tube itself not being rotated but merely advanced may have the rate of feed of the tube so timed as to determine the pitch of the spiral wound thereon. In other words, by adjusting the feed, the pitch of the spiral fin may be varied for different jobs. Moreover, the machine carrying its fin supply and revolving it about the axis of the tube enables the machine to operate at relatively high speeds, because the drawing of the fin material from the supply is within the speed of rotation of 'the head 34 of the machine. Thus there is no drag or undue pull on the supply as is likely to be encountered in a machine wherein the supply is arranged exterior of the rotating parts of the machine, and is not carried by the same. Consequently, with my improved machine the rate of production may be greatly increased, in that the fin material may be applied faster to the tube than heretofore, Then again with the tube fed merely endwise through the machine, and not revolved, no complicated form of feed and revolving rollers or equivalent mechanism is required inthe drum 24, with the result that the speed of rotation of the machine is not reduced as when a reducing gearing is required to slow down the machine to the feed required for the tube therethrough. With the machine operating at relatively high speeds and the tube stationary in so far as rotation is concerned, the fin-strip material may be applied with sufiicient tightness around the exterior of the tube to hold it on the tube without the necessity of soldering the parts together as the fin is applied. This has the advantage of-avoiding the necessity of a solder bath or a solder applying fixture in associaticn with the machine, thereby allowing such parts to be operated remote from the machine, and thus enable the machine to produce tubing devoid of solder, if that type of product is required. Other advantages of my invention will be apparent to those skilled in the art to which it pertains.

The details of construction and arrangement of parts shown and described may be variously changed or modified without departing from the spirit and scope of my invention, except as pointed out in the appended claims.

' I claim as my invention:

1. In a machine for producing spiral fin tubing, a revoluble head having an axially disposed passage through which a tube may be fed, said head having an annular flange about said passage and forming a support for a supply of fin strip material in reel or coil form, said flange having a slot in one part of its circumference whereby the fin strip material may be drawn from one circumference of the coil through the slot and be presented to the tube for spiral winding thereon.

2. A machine for producing spiral fin tubing, comprising a revoluble head, a tubular'guide disposed axially of the head and opening theretlirough, means for feeding a tube through said guide past the head, means on the head for supporting a supply of fin strip material in coil or reel form about said guide. a rotary disk carried by the head and overlapping with the adjacent end of the guide, means carried by the head and, acting in the rotation thereof to turn the guide and the disk in a direction to draw the fin strip material from the coil and present it to the tube for spiral winding thereon, and means for rotating said head.

3. A machine for producing spiral fin tubing, comprising a revoluble head, a tubular guide disposed axially of the head and opening therethrough, means for feeding a tube through the guide past the head, means on the head to support a supply of fin strip material in coil or reel form about the guide, a rotary disk carried by the head and overlapping the adjacent end of the guide, and means including meshing gears actuated in the rotation of the head for'rotating the guide and the disk in a direction to draw the fin strip material from the coil and present it to the tube for spiral winding thereon," and means for rotating said head.

i. A machine for producing spiral fin tubing, comprising a revoluble head, a tubular guide disposed axially of the head and opening therethrough, means for feeding a tube through the guide past the head, means on the 'head to support a supply of fin strip material in coil or reel form about the guide, a rotary disk carried by the head and overlapping the adjacent end of the guide, gearing associated with the guide and the disk for rotating the same in the turning of the head to draw the fin strip material from the coil and presenting it to the tube for spiral winding thereon, the gearing and the disk being arranged at opposite ends of the guide, and means for rotating the head.

5. A machine for producing spiral fin tubing, comprising a rotary drum, a head fixed to said drum at one end and rotated in unison therewith, a tubular guide extending axially through the drum and the head, means for feeding a tube through the guide past the head, means on the head to support a supply ofv fin strip material in coil or reel form about the guide, a rotary disk carried by the head and overlapping the adjacent end of the guide, gearing located at the end of the drum opposite the head for imparting rotation to the disk and the' guide in the rotation of the drum, and means for rotating the drum.

6. A machine for producing spiral fin tubing, comprising a rotary drum, a head fixed to the drum and rotatable therewith, a tubular guide extending axially through the ,drum and the head, said head having an annular flange about the guide to support a supply of fin-strip material in coil or reel form and to provide a cavity inside of said flange, means including a roller carried by the head in the cavity formed by said flange, and cooperating with said guide for'presenting the fin-strip material in edgewise relation to the tube for spiral winding thereon in the rotation'of the head, and means for rotating the head.

7. In a machine for producing spiral fin tubing, a revoluble head having an axially disposed passage through which a tube may be fed, said head having an annular flange about said passage, a supply of fin strip material carried by the head about said flange in coil or reel form, means carried by the head for drawing the fin strip materialfrom the coil and presentingit in edge-wise relation to the tube for spiral winding thereon, a cover for the outer side of the coil,and means providing a releasable connection between the cover and the flange, said means being so constructed and arranged that the cover may be attached to and detached from the flange on'turning the cover in opposite directions.

8. In a machine for producing spiral fin tubing, a revoluble head having an axially disposed passage through which a tube may be fed, said head having an annular flange about said passage, a supply of fin strip material carried by the head about saidfiange in coil or reel form, means carried by the head for drawing the fin strip material from the coil and presenting it in edge-wise relation to the tube for spiral winding thereon, a cover for the outer side of the coil, and means providing a pin and slot connection for releasably connecting the cover to the flange.

9. In a machine for producing spiral fin tubing, a revoluble head having an axially disposed passage through which a tube may be fed, said head having an annular flange about said passage and forming a support for a supply of fin strip material in reel or coil form, means carried by the head for drawing the fin strip material from the coil and presenting it in edgewise relation to the tube for spiral winding thereon, and a cover for the outer side of the coil and connected to the flange, said flange and cover being cut away to provide a passage for the feed of the fin strip material from the coil to the tube.

10. The method of making a helical winding for finned tubes or other purposes, consisting in revolving a supply of fin strip material in coil form about an axis passing through the coil, drawing the fin strip material from the coil toward said axis, and at the same time so reducing the cross-sectional shape of the strip material that it may wind in successive convolutions in spiral form about said axis upon an adjacent core.

11. The method of making a helical winding for finned tubes or other purposes, consisting in revolving a supply of fin strip material in coil form about an axis passing through the coil, drawing the fin strip material from the coil toward said axis, and at the same time presenting the strip in edgewise relation to said axis and subjecting the strip to a squeezing action from opposite sides to cause the strip to wind in successive convolutions in spiral form about said axis in edgewise relation thereto on an adjacent core.

12. The method of making a helical winding for finned tubes or other purposes, consisting in revolving a supply of fin strip material in coil form about an axis passing through the coil, drawing the fin strip material from the coil toward said axis, and at the same time reducing the cross-sectional shape of the strip by a rolling action applied to the sides thereto to cause the strip to wind in successive convolutions in spiral form about said axis on an adjacent core.

13. An apparatus for forming a helical winding from strip metal stock, compressing means for supporting the stock in coil form, means for revolving the coil about an axis passing through the coil, a pair of pressure rollers having opposed faces between which the stock passes, and means for rotating said rollers to draw the strip stock from the coil and so reduce the cross-sectional shape of, the strip stock as it passes between said rollers to cause the strip to wind in successive convolutions in spiral form upon an adjacent core.

14. The method of producing spiral fin tubing, which consists'in revolving a supply of fin strip? material in coil form about an axis passing through the 'coil, supporting and-feeding a tube through the coil along said axis without rotating the tube, drawing the fin strip material from the coil and presenting the strip in edgewise relation to the tube and at the same time so changing the cross-sectional shape of the strip that the strip may be wound in spiral form on the tube in edgewise relation thereto as the tube leaves the support. I

15. The method of producing spiral fin tubing, which consists in revolving a supply of fin strip material in coil form about an axis passing through the coil, supporting and feeding a tube endwise through the coil along said axis without rotating the tube, drawing the fin strip material from one circumference of the coil, and presenting the strip in edge-wise relation to the tube and atthe same time so changing the crosssectional shape of the strip that it may be wound in spiral form on the tube as the tube leaves the support.

16. The method of producing spiral fin tubing, which consists in revolving a supply of fin strip material in coil form about an axis passing through the coil, supporting and feeding a tube endwise through the coil along said axis without rotating the tube, drawing the fin strip material from the outer circumference of the coil and presenting the strip in edge-wise relation to the tube and at the same time reducing the thickness of the outer marginal portion of the strip that it may be wound in spiral form on the tube as the tube leaves the support.

17. The method of producing spiral fin tubing, which consists in revolving a supply of fin strip material in coil form about an axis passing through the coil, supporting and feeding a tube endwise through the coil along said axis without rotating the tube, drawing the fin strip material from the inner circumference of the coil and presenting the strip in edge-wise relation to the tube and at the same time so changing the crossvsectional shape of the strip that it may be wound in spiral form on the tube as the tube leaves the support. 7

18. In a machine for producing spiral fin tubing, a revoluble head, a tubular guide disposed axially of the head and opening therethrough, means for feeding a tube through the guide past the head, means on the head for supporting a supply of fin strip material in coil or reel form about the guide, means for rotating the head and the guide about the tube, and means carried by the head and acting in conjunction with the rotating guide for drawing the strip material from the coil and presenting it in edgewise relation to the tube and at the same time so reducing the cross-sectional shape of the strip that it may be wound in spiral form on the tube.

19. In a machine for producing spiral fin tubing, a revoluble head, a tubular guide disposed axially of the head and opening therethrough, means for feeding a tube through the guide past the head, means on the head for supporting a supply of fin strip material in coil or reel form about the guide, means for rotating the head and the guide about the tube, and means carried by the head and acting in conjunction with the end surface of the rotating guide at the head for drawing the fin strip material from the coil and presenting it in edgewise relation to the tube and at the same time subjecting the strip to a squeezing action from opposite sides :obcause the strip to wind in spiral form on the 20. In a machine for producing spiral fin tubing, a revoluble head, a tubular guide disposed axially of the head and opening therethrough, means for feeding a tube through the guide past the head, means on the head for supporting a supply of fin strip material in coil or reel form about the guide, means for rotating the head and the guide about the tube, and means carried by the head and acting in conjunction with the rotating guide for subjecting the strip as it is presented in edgewise relation to the tube to a rotative action for drawing the strip from the supply coil and causing the strip to wind in successive convolutions in spiral form on the tube.

21. In a machine for producing spiral fin tubing, a revoluble head, a tubular guide disposed axially of the head and opening therethrough, means for feeding a tube through the guide past the head, means on the head for supporting a supply of fin strip material in coil or reel form about the guide, means for rotating the head and the guide about the tube, and means carried by the head and forming in conjunction with the end surface of the guide at the head a triangular throat for the passage of the strip to the tube, whereby the normal rectangular crosssectional shape of the strip will be changed to conform to the throat for winding the strip in successive convolutions in spiral form on the tube.

22. In a machine for producing spiral fin tubing, a revoluble head, a tubular guide disposed axially of the head and opening therethrough, a supply of fin strip material carried by the head about said guide in coil or reelform, a revoluble support on, the head for the inner circumference of the coil, means for rotating the head and the guide about the tube, and means carried by the head and acting in conjunction with the rotating guide as the tube leaves the same for drawing the fin strip material from the coil and presenting it in edgewise relation to the tube and at the same time so reducing the crosssectional shape of the strip that it may be wound in spiral form on the tube.

CHARLES W. OWSTON.