US3220234A

US3220234A - Machine for forming helical lock seam pipe

Info

Publication number: US3220234A
Application number: US157350A
Authority: US
Inventors: Harper Laffie
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-12-06
Filing date: 1961-12-06
Publication date: 1965-11-30
Anticipated expiration: 1982-11-30
Also published as: GB974097A

Description

Nov. 30, 1965 HARPER MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6. 1961 4 Sheets-Sheet 1 INVENTOR. LAFF/E HARPER A 7'7'ORNE VS Nov. 30, 1965 HARPER MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6, 1961 4 Sheets-Sheet 2 INVENTOR. LAFF/E HARPER ATTORNEYS Nov. 30, 1965 L. HARPER 3,220,234

MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6, 1961 4 Sheets-Sheet 5 FIG l8 INVENTOR. LAFF/E HARPER A 7' TORNE VS Nov. 30, 1965 L. HARPER 3,220,234

MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6, 1961 4 Sheets-Sheet 4 INVENTOR. LAFF/E HARPER United States Patent C) 3,220,234 MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Laffie Harper, 1192 Montgomery Ave., San Bruno, Calif. Filed Dec. 6, 1961, Ser. No. 157,350 11 Claims. (Cl. 72-50) This invention relates to a machine for forming helical lock seam pipe, and has for one of its objects the provi sion of a machine of the above type that is provided with a simple structure enabling the machine to be adjusted, within a substantially shorter time than has heretofore been required in other machines for the same purpose, for making pipe of a different diameter.

Another object of the invention is the provision of improved means in a machine for making helical lock seam pipe that enables quickly converting the machine to the making of pipe of different diameters, and from metal strips of different gauges and widths.

A still further object of the invention is the provision of a machine for making helical lock seam pipe in which a strip of metal from which the pipe is formed is moved longitudinally thereof between a final pair of rollers that extend at right angles to the longitudinal axis of the strip and whose axes are in a common vertical plane, and which strip is guided toward helical form, and the seam locked, in said plane at said rollers.

An additional object of the invention is the provision of a simple compact machine in which the coil from which the strip that forms a helical or spiral pipe is drawn, is supported in a position and manner that not only improves the balance of the machine, but that contributes to making the machine compact and to taking the stress out of the strip.

In brief, heretofore most machines of which I am aware for making helical lock seam pipe are provided with relatively expensive and complicated structure for bending and guiding the strip as it forms the helix. Usually such structure includes a plurality of rollers or rollers in conjunction with guide plates. The assembly of such rollers or plates provides a forming head, and the changes required for making different diameter pipe, using a strip of the same gauge and width takes a relatively long time, to say nothing of the changes that would be required where a different width strip or metal of a different gauge is to be used.

In the present invention the structure is such that Within substantially less than ten minutes time the machine can be adjusted to making pipe of a different diameter from the same width strip. For example, it is customary to fabricate pipe of from approximately four to eight inches in diameter from a standard flat metal strip that is slightly less than six inches in width. This metal may be of different gauges.

Provision is made in the machine hereinafter described that eliminates the necessity for changing rollers where a change within normal limits is made in the gauge of metal used, and the change from one helix forming head to another for the different diameter pipe can be made in approximately seven minutes time. Also provision is made for quickly adjusting the final margin bending rollers, that make the final bend for the interlocking seam forming portions, to regulate the degree of bend that may be required for strips of different gauges.

The present machine is not restricted to making pipe of a greater diameter than eight inches from the same width strip. However, it is usually found to be more economical and practical to use a wider strip for making pipe of greater diameter than eight inches. The present machine is readily adapted to make pipe of any practical diameter above eight inches.

3127203234" Patented Nov. 30, 1965 One of the important features of the present invention is the particular structure of the helix forming head, which head is extremely simple, economical to make, and accurately and positively guides the strip at all points along the length of the latter with a minimum of frictional resistance.

Other objects and advantages will appear in the description and drawings.

In the drawings:

FIG. 1 is a top plan view of the machine.

FIG. 2 is a side elevational view of the machine, with the strip of metal from which the pipe is formed being shown thereon.

FIG. 3 is an enlarged, fragmentary cross sectional view through the seam locking rollers taken along line 33 of FIG. 1.

FIG. 4 is an enlarged, fragmentary elevational view looking at the outer ends of the seam locking rollers, and showing the guide shoe on the pipe forming head.

FIG. 5 is a cross sectional view taken along line 55 of FIG. 4.

FIG. 6 is a fragmentary top plan view of the pipe forming head showing a portion of the pipe as it is formed.

FIG. 7 is a fragmentary cross sectional view taken through a portion of the pipe showing the flange along one marginal portion of the strip before the formation of a seam.

FIG. 8 is an enlarged fragmentary sectional view taken through a portion of the adjacent sides of one of the three pairs of margin forming rollers.

FIGS. 9, 10, 11, respectively, are taken along lines 9-9, 10-10 and 11-11 of FIG. 2 and are enlarged to show the approximate relationship between the rods of the helix forming head and the flange on the strip that forms the pipe.

FIG. 12 is an enlarged vertical fragmentary sectional view taken through adjacent parts of the middle set of margin forming rollers, along line 12-12 of FIG. 1.

FIG. 13 is a fragmentary elevational view of the final set of margin forming rollers, the strip that is being formed being shown in cross section.

FIG. 14 is an edge elevational view of a filler ring adapted to be used on the coil supporting drum where the coil is a narrow strip of metal.

FIGS. 15, 16, 17 are fragmentary cross sectional views taken substantially along lines 1515, 1616 and 17-17, respectively, of FIG. 4.

FIG. 18 is an edge view of one of the lock seam form ing rollers that may be substituted for one of the rollers of FIG. 3 where lighter gauge metal is to be used.

Referring to FIGS. 1, 2 the machine herein illustrated comprises a horizontally elongated frame generally designated 1, and which frame supports three pairs of superposed rollers for rotation, which pairs, from right to left as seen in FIG. 1, are generally designated 2, 3 and 4; These are the rollers that are adapted to bend the marginal portions of the strip of sheet metal that is to form the pipe for forming the seam, and they also drive the s rip.

The upper rollers of pairs 2, 3, 4 are designated 5, 6, 7 and the lower rollers are designated 8, '9, 10. Rollers 5, 8 are the right hand pair (FIG. 2), rollers 6, 9 the middle pair and rollers 7, 10 the left hand pair.

Shafts in coaxial extension of the inner ends of these rollers (the upper ones are seen in FIG. 1) are journalled for rotation on the frame 1 or in bearings carried by the frame, the shafts in extension of

rollers

5, 6, 7 being seen in FIG. 1 and designated 12, 13, 14. The shafts for rollers 8, 9, 10 are below shafts '12, 13, 14.

Other shafts

15, 16 also rotatably supported on the frame 1 are between the shafts of rollers 8, 9 and 9, 10 and these shafts and the shafts of rollers 5-10 are connected by gears 17 (FIG. 1), for positive rotation of the pairs of rollers 2, 3, 4 for driving a strip of sheet metal 20 from right to the left as seen in FIG. 2.

A shaft 21, also rotatably carried by frame 1, has a sprocket wheel 22 secured thereto, which wheel, in turn, is connected with a motor 23 by a sprocket chain 24. A gear 25 on said shaft 21 is in mesh with a gear 26 on the shaft that carries roller 10.

Beyond or to the left of the third pair 4 of rollers 7, 10 are the seam locking rollers, one roller 27 (FIGS. 3, 4) being positioned over a set of three rollers '28, 29, 30 that are below roller 27.

Roller 27 is secured on the outer end of a shaft 32 that is journalled for rotation in bearings that are rigid on frame 1, and the three rollers 28-30 are rotatably carried on the outer end of a shaft 33 that is parallel with and below shaft 32, and that is also journalled for rotation in hearings on frame 1.

The rollers 28-30 are independently supported on their own bushings, as seen in FIG. 3, so they can rotate relative to each other, as will later be explained.

Shafts

32, 33 are connected by corresponding gears 34 for driving their adjacent sides in the same direction as the margin forming sets of rollers 2, 3, 4 and a gear 35 (FIG. 1) on shaft 33 in line with gears 25, 26 is in mesh with gear 25 for driving the seam locking rollers.

These seam locking rollers are at the discharge end of the machine while the pair 2 of margin bending rollers is at the feed end of the machine.

The helix forming head is generally designated and is positioned with its inlet and outlet ends adj a-cent to the seam locking rollers 27-30 and at the side of said rollers adjacent to the third pair 4 of marginal forming rollers.

This helix forming head will be explained more in detail later on, it being suflicient at this time to state that it engages and guides one preformed marginal portion of the strip 20 to guide it along a helical path and to lapping relation to the other preformed marginal portion of the strip so that the seam locking rollers will lock them together to form the seam of the helical pipe.

The main frame 1 is supported on a subframe 41 (FIG;

2) for swinging of said main frame about the vertical axis of a pivot 42, which axis extends vertically through the center of the

seam locking rollers

27, 29, and at the opposite or feed end of the machine, a vertical shaft 43 is rotatably carried on the main frame, having a suitable handle 44 at its upper end for manually rotating said shaft. I

The lower end of shaft 43 has a gear 45 secured thereto, which gear is in mesh with the teeth of an arcuately extending rack 46 (FIG. 1) that is rigid with the subframe. By manually rotating shaft 43 the main frame may be swung about pivot 42 to different positions, so that the helical pipe 47 (FIG. 6) extending away from the seam locking rollers and from the helix forming head 40 can move to any desired position extending ang'ularly from the main frame.

Inasmuch as substantially the entire weight of the machine is on the subframe 41 between pivot 42 and the feed end of the machine, provision is made for supporting the heavy strip-supporting coil 48 in a position at the side of pivot 42 that is opposite to the feed end of the machine. An extension 50 extends from the helix forming end of frame '1 longitudinally of the latter, and a shaft 51 projects laterally of said extension and supports a drum 52 for rotation thereon, with said drum in proper alignment with the pairs of rollers 2-4.

This drum has heads 53 at its ends, and the coil 48 has a core that is of greater diameter than the external diameter of heads 53. Thus the coil may be positioned on the drum over the outer head of the latter, without removing the drum.

At the feed end of the machine is a pair of opposed,

peripherally flanged wheels 55 secured on a shaft 56 that is supported for rotation on the frame 1, the said wheels being in alignment with the heads 53 of the drum 52.

The strip 20 from coil 48 is carried under, around and over the radially outwardly facing annular surfaces of wheels 55 between the radially outwardly projecting annular flanges 57 on said wheels and then is moved between a pair of

parallel guide plates

58, 59 that are formed with opposed, horizontally extending grooves in their opposed sides into and through which grooves the marginal: portions of the strip 20 extend. The dotted lines 60 (FIG. 1) indicate the grooves.

The level of these grooves 60 is substantially the level of the marginal forming portions of the pairs 2, 3, 4 of marginal forming rollers, and the spacing between

guide plates

58, 59 is such that the marginal portions of the strip 20 will be guided to their proper positions between the sets 2, 3, 4 of the marginal forming rollers.

In the event the width of the strip 20 is to be changed, a filler ring 62 (FIG. 14) of an inside diameter greater than the outer peripheral diameter of the outer head 53 of drum 52 is slipped over said outer head and onto the drum. Rods 63 secured at one of their ends to said ring 62 at points equally spaced around the ring will space the ring from the inner head of the drum the desired distance so that the space between the ring 62 and the outer head 53 will be equal to the width of the new strip.

The marginal forming rollers 5-10 are secured on the shafts carrying them by bolts 64 on the ends of said shafts, and they are keyed to said shafts for rotation therewith, hence they can readily be removed and others having their marginal forming portions spaced for the new width strip may be substituted.

Plates

58, 59 are removably held in place on suitable supports 65 that are bolted at one of their ends to frame 1, and their spacing can be readily changed to accommodate the new width strip. Also wheels 55 are adjustable relative to each other on the shaft 56.

The seam locking rollers may be replaced by others if desired, where different gauge metal is used for the pipe.

The helix forming head is readily unbolted from the frame and another of different diameter substituted when a different diameter pipe is to be formed. A bolt 66 extends through a slot 68 in a block 69 that is connected with and supports the receiving end of the helix forming head. This bolt extends into frame 1, and another bolt 67 extends through a bracket 70 that is connected with the other end of the helix forming head 40, and into frame 1. Similar structure is provided for each helix forming head with suitable bolt holes formed in the frame 1 for securing the different helix forming heads to the frame.

Upon actuation of motor 23 and after the leading end of strip 20 has been drawn from coil 48, under and over wheels 55, and through grooves 60 in supporting

plates

59, 58 to between the rollers of set No. 2, the said strip will be driven longitudinally thereof through the rollers of pairs Nos. 2, 3, 4 and around the helix forming head to the seam locking roller.

The helix forming head only engages the strip 20 along the flange 71 that is formed along only one marginal portion of the strip. This flange is directed downwardly by the pairs 2-4 of the margin forming rollers while the opposite marginal portion of the strip is formed with an upwardly opening channel 72 by the same rollers (FIG. 12).

The helix forming head guides the flange 71 into the upwardly opening channel, and both the flange and the sides of the channel are similarly slightly inclined relative to vertical (FIG. 5) so that the seam locking rollers will force said flange and said sides to horizontally positioned tight interlocking relation to form the seam 73 (FIG. 3).

Once the seam is locked the helical pipe 47 will be continuously formed as long as the strip 20 is fed through the machine.

These operations, in themselves, are generally performed by conventional helical pipe forming machines.

The specific combinations, structures and methods that are particularly important in the present machine will now be considered separately.

Coil, frame and strip feed structure and arrangement As has been briefly mentioned, by supporting the coil 48 at the side of pivot 42 that is opposite to the main frame 1 of the machine, main frame is more readily and easily moved on the subframe since the weight on the subframe is to a substantial degree counterbalanced, and since the adjustment of the machine is usually made when there is a substantial coil on the machine, this is important.

Another advantage of the arrangement is that by drawing the strip around the wheels 55, the stresses are substantially taken out of the flat strip leading to the marginal forming rolls, provided the strip is kept under tension when drawn around the wheels 55. This tension is maintained by suspending the coil on drum 52 so that the greater weight of the coil is below the axis of the drum, and by drawing the strip from the lower side of the coil. This arrangement provides an automatic brake that will maintain the length of the strip between the coil and the roller sets 2-4 under constant tension.

A further advantage of the arrangement of the coil, frame 1 and the parts on said frame is that the machine is more compact than where the supply coil is at the feed end. Usually heretofore, in the latter structure, the strip is drawn from the upper side of the coil, and as the coil decreases in diameter the strip from the coil to the forming rollers changes direction or means must be provided to keep the strip straight as the size of the coil decreases.

Rollers of sets 2, 3, 4

A common feature of the rollers 5-10 which make up the pairs 2, 3, 4 is the formation of the portions of these rollers between their opposite end portions.

Insofar as the rollers of sets 2, 3 are concerned, which are

rollers

5, 8 and 6, 9, their opposite end portions are conventional.

FIG. 12 is illustrative of the cross sectional contours of the ends of: the middle rollers 6, 9, or pair No. 3, in which the outer end portion of roller 6 (relative to frame 1) is formed with a radially outwardly projecting flange 75 that is adapted to enter a generally complementary recess 76 opposite thereto in lower roll 9, the latter being an annular outwardly opening V-shaped recess, and the inner surface of the annular flange 75 being slanted to correspond to the axially inner side of the V.

The opposite end of roller 6 is formed with a radially outwardly projecting annular rib 77 having a slanted axially facing surface that is directed generally toward the outer end of the roller. The end of roller 9 that is opposed thereto is relieved as at 78 to receive the rib '77.

The first roller set No. 2, which consists of rollers 5, 8, have substantially the same structure, except that the ribs or flanges do not project as far and the recesses that receive them are more shallow, and the inclined surfaces are less steep.

Thus, as the strip passes between set No. 2 of rollers, the marginal portion of strip 20, which will ultimately be the flange 71 of FIG. 3, is slightly bent downwardly, and when it passes between the rollers 6, 9 of set No. 3, the marginal portion will be further bent to the position shown in FIG. 12.

At the same time, the channel 72 along the opposite marginal portion of the strip will be progressively formed, first by the rollers of set No. 2, and then by the rollers 6, 9 of set 3, as seen in FIG. 12. This marginal forming structure is much the same as in US. Letters Patent No. 1,288,134 issued December 17, 1918 to C. G. Naylor.

However, heretofore adjustment must be made for strips of different gauges or thickness.

In the present instance, as seen in FIG. 1 and more in detail in FIG. 8, the intermediate or central portion of each roller is formed with a row of spaced annular outwardly projecting ribs which may have fiat radially outwardly facing surfaces. The ribs on the

upper rollers

5, 6, 7 are staggered relative to the ribs 81 on the lower rollers 8, 9, 10 and

adjacent ribs

88, 81 are spaced axially of the rollers and the ribs or ridges on one roller of each pair are in non-lapping relation, axially of said rollers, with the ribs or ridges on the other roller, so that a relatively heavy gauge strip will be sprung slightly between adjacent rollers 80 and adjacent rollers 81, while lighter gauge metal will be merely tightly gripped by the rollers, without being sprung. This does not corrugate the strip, although in relatively heavy gauges there may be a slight distortion or impres sion where the

ribs

80, 81 engaged the strip, which, however, appears only in the heaviest gauge metal the machine is intended to handle.

The advantage of providing a structure that is adapted to automatically and without adjustment handle metal strips of several gauges is believed to be obvious. This structure becomes more important when the structure of the rollers of set 4 or rollers 7, 18 are considered.

Rollers of set 4 0r final marginal forming rollers Referring to FIG. 13, the upper roller 7 is formed at its outer end with a coaxial threaded extension 82 on which is threadedly supported a channel forming annular ring 83, which ring projects radially outwardly of the main body of the roller and into a relieved portion 84 at the outer end of the lower roller 10.

The axially inwardly facing surface of the ring 83, which is the surface that faces toward frame 1, is inclined inwardly from its outer peripheral edge.

This ring 83 may be moved toward or away from the shoulder 85 that is at the bend between the central body of strip 20 and the inner side of the channel that is formed in the marginal portion of strip 20.

FIGS. 12 and 13 should be compared, since the channel portion of strip 20 as seen in FIG. 12 is the shape it has when it reaches the rollers 7, 10.

When said channel portion reaches the rollers 7, 10 the outer side 86 of the channel 72 will engage the slanted side of ring 83, as seen in FIG. 13, and it will be bent a substantial distance past a vertical position to a position that may be almost parallel to the inner side 87 of the channel. However, this outer side 86 will spring back to a degree after it leaves the rollers 7, 10 and the degree to which it will so spring is according to the characteristic of the metal and to the gauge of the metal.

By enabling the ring 83 to be quickly adjusted relative to the shoulder 85 of the lower roller 10, the correct degree of bend of the outer side 86 of the channel to compensate for the spring-back, can be readily determined. After the ring is in its adjusted position, a set screw 88 is tightened to hold it in adjusted position.

At the flange forming end of the lower roller 10, a ring 89 similar to ring 83 is threadedly supported a threaded portion 90 of the shaft of roller 10. When the flange 71 of the strip 20 leaves the rollers 6, 9 of the middle set 3, it is substantially as seen in FIG. 12 and it must be bent a predetermined degree past a position in which it is at right angles to said strip so it will spring back to a position such as seen in FIG. 5.

Ring 89 has an axially facing slanted surface that faces toward the outer end of the roller 10, and this slanted surface engages the flange 71 and bends it toward the axially facing shoulder 91 of roller 10 that is in spaced opposed relation to the slanted side of the ring 89. By adjusting ring 89 on the threaded portion 90 of the shaft of rollers 18, the degree of bend of the flange 71 can be varied according to the gauge of metal and the character of the latter. Set screw 96 locks ring 89.

In connection with the above, it may be pointed out that while the metal in a coil that is made is uniform in its resiliency for a particular gauge, it does not necessarily follow that another coil having the same specifications will have exactly the same resilient characteristics. Hence the provision for rapid adjustability of the last pair of margin forming rollers, as above provided, is quite important.

Helix forming head and guide shoe The helix forming head, generally designated 40, comprises a pair of axially spaced, substantially helically extending

rods

92, 93, the rod 92 being the outermost rod of the helix and the rod 93 being the innermost rod (FIG. '2). This pair of rods preferably have cylindrical opposed surfaces that define the opposite sides of a helically extending passageway or path 94 that opens generally oppositely outwardly at its ends so that the one outwardly opening end faces the oncoming flange 71 of strip 20 after the strip passes the No. 3 pair of rollers.

The opposite open end of the passageway 94 is directed toward the space between the seam locking rollers 27, 29 (FIG. 3). The helix extends above the seam locking rollers. The end of the head 40 that faces toward the oncoming flange 71 may be called the inlet end of the head, while the opposite end is the outlet end.

The rod 92, for most of its length, is offset relative to the rod 93 commencing at the inlet end of the head in a direction axially of the helix toward the outlet end (FIGS. 9-l0) and it may, at the outlet end, be disposed substantially below rod 93 (FIG. l-l). However, at the initial length of the rods, the juncture of the flange 71 and the main body of the strip will be between the

rods

92, 93. As the strip is driven into passageway 94 between the rods, the rod 93 will force the flange and the portion of the strip therealong to a helical path defined by the radially inwardly facing surface of the outer rod 93. The rod 93 will prevent the flange from moving straight, since the juncture between the flange and strip engages the inner surface of said rod above the lowermost point on the latter.

Once the flange is bent in the proper direction it will automatically follow a helical path, and will emerge from the outlet headed toward the space between the seam locking rollers 27 29.

In order to insure against the possible drifting of the flange out of the helical path leading to the outlet, a third rod 95 is rigidly secured to the

rods

92, 93 in spaced horizontally opposed relation to the rod 92, so as to extend across the outer surface of flange 71 (FIGS. 10, M). This third rod or flange engaging rod may extend from a point about half way around the rods to approximately the outlet end of the path.

The

rods

92, 93 and 95 are held together in spaced relation by any suitable connectors 98 that clear the flange 71 as the latter is carried around the helix.

After the flange 71 has passed out of the outlet end of the passageway or path 94, it passes below a guide shoe 99 (FIGS. 4, in engagement with the generally downwardly facing convex surface of said shoe, which surface terminates substantially at the space between locking

rollers

27, 29. The shoe positively guides the flange 71 into the upwardly opening channel '72 of strip 20 that, in turn, is guided between the

seam locking rollers

27, 29 below a horizontal guide plate 100 that is below and in rearward extension of shoe 99 (FIG. 5).

The shoe 99 and guide plate 100 may be welded or otherwise secured together, and, as seen in FIG. 5 and FIGS. 16, 17, the shoe projects laterally of the plate 100 and the underside of said shoe along the free lateral edge thereof on the laterally projecting part may be convexly curved, which curved surface contributes to guiding the flange 71 to its proper position for entering channel '72. The end of the shoe that extends between the

rollers

27, 29 terminates as close as possible to a vertical line extending betwen the axes of said rollers.

As seen in FIG. 1, a plate 101 secured to frame 1 by bolts 102 and extending through slots 103 in said frame carries the guide shoe 99 and plate 100. This plate 101 may be thus adjusted longitudinally of the frame 1 to properly position the shoe 99.

Seam locking rollers The

rollers

27, 28, 29 and 30, as seen in FIG. 3, are arranged so that

rollers

28, 29 and 30 are on shaft 33 while roller 27 is keyed to shaft 32.

Shafts

32, 33 are positioned with their axes in the same vertical plane.

Where there is a change in the gauge of metal that is being used for the pipe, the rollers 2830 would be changed. The thinner the metal the greater the diameters of rollers 28-30.

As seen in FIG. 3 there is a space between the outer peripheries of the

rollers

27, 29 in which the flange 71 and channel 72 will pass.

The spacing between rollers 27 29 is such that the flange 71 and the sides of channel 72 will be pressed tightly to gether (FIG. 3), and since the outer peripheries of

rollers

27, 28, 30 engage the strip 20 at opposite sides of the seam, with roller 29 being of reduced diameter, the seam '73 will not project into the pipe but will be wholly positioned outside the pipe (FIG. 7) leaving the inside of the pipe unobstructed by the seam.

Rollers

28, 29, 30 are on separate bearings since they may rotate at different peripheral rates of speed. The fact that shaft 33 is driven in the same direction as the rollers facilitates their rotation.

Once a complete starting helix is formed in strip 20 and the seam is locked, the outer rod 92 functions mainly to prevent radial outward expansion of the flanged por tion of the strip. The pipe will be formed more or less automatically. In the helix forming head, the outer rod 92, at the start of the formation of a helix in the strip must control the diameter of the pipe and the flange 71 must be started in the true desired spiral and accurately guided into the channel 72 at the outlet end of the head.

To change the diameter of .a pipe it is merely necessary to remove the two bolts holding the head in place and substitute a head of the desired diameter, which may be accomplished in a few minutes time.

It should also be noted that the locking of the seam is accomplished at a point along a line that is at a right angle to the longitudinal axis of the strip 20, said line being parallel with the axis of rollers 28-30. The strip is not fed to the seam locking rollers at an oblique angle, hence all of the rollers including the seam locking rollers rotate about parallel axes.

Attention is called to the fact that the roller 29 is formed with an annular outwardly projecting flange 104 along the side of the roller that is adjacent to the outer end roller 28.

Where a heavier gauge metal than that illustrated is being used for the pipe, this flange would be of greater axial thickness or may even be eliminated for the heaviest gauge metal that the machine is adapted to handle. Where lighter gauge metal is being used it may be thicker as seen in FIG. 18. The thickness of the flange determines the axial width of the space in which the flange 71 and channel 72 extend, and this width is such as to insure the tightest possible seam. If the same axial dimension of the space were used for all gauges of metal, then the seam would not be as tight as it should be since the axially opposed surfaces defining width of the space in which the seam is formed would not axially crowd the metal of the flange and channel together in the lighter gauge metals to insure a tight seam. However, by varying the thickness of the flange 104, the axial dimension of the space between flange 104 and roller 30 may be varied. Of course, the outer diameter of the portion of roller 29 at the side of flange 104 would be greater (FIG. 8) where metal of lighter gauge is being used, or it would be less where the gauge is heavier.

It should be noted that the outer periphery of flange 104 will not necessarily be in driving relation with strip 20. The mounting of the roller 29 on a bushing separate from the bushings supporting the

rollers

28, 30 enables a differential in the rate of rotation of the rollers 2830.

In conclusion it has been mentioned, with reference to the helix forming head 40, that suitable bolt holes are provided in the frame for securing different helix forming heads to frame 1. The same bolts in the same places are employed where the strip that forms the diiferent diameter pipe is of the same width. It is only when a wider strip is used that there is any occasion to employ a diflerent bolt hole.

I claim:

1. In a machine for forming helical lock seam pipe from a continuous sheet metal strip and which machine includes;

(a) strip moving means for moving said strip generally horizontally longitudinally thereof in one direction, and

(b) flange forming means for forming a downwardly projecting flange along one marginal portion of said strip during said movement, and

(c) channel forming means for forming an upwardly opening channel along the other marginal portion of said strip during said movement, which channel is adapted to receive said flange therein when said strip is helically formed;

(d) a pair of helically extending rods one spaced radially within the other to provide an inner helical rod and an outer helical rod;

(e) said rods defining substantially a single coil of a helix about a horizontal axis with their terminating ends lowermost and at points spaced horizontally apart a distance substantially equal to the distance between said flange and channel;

(f) the space between said rods opening oppositely outwardly at the terminating ends of said helix; and

(g) means supporting said helix of rods with its axis above the path of travel of said strip and at right angles to the direction of movement of the latter and with the outwardly opening space between said rods at one end of said pair thereof facing oppositely to the direction of movement of said strip and substantially in alignment with said flange for receiving the portion of said strip along said flange between said rods, and with the outwardly opening space between said rods at their opposite ends fac ing the direction of movement of said strip and adjacent to and over the said channel,

(h) said outer helical rod being slightly offset relative to said inner helical rod axially of the helix at said one end of said pair of rods toward the edge of said strip having the channel therein to support the juncture between said flange and said strip against said inner helical member for following the said inner helical member to thereby form said flange into a helix and to guide the latter into the open side of said channel during said movement of said strip.

2. In a machine as defined in claim 1;

(i) rod holding means at opposite ends of said pair of rods holding them rigidly relative to each other in their spaced relation,

(j) and means for removably securing said rod holding means on said machine in said position for forming said strip to a helix.

3. A head for use on a helical lock seam pipe forming machine to form a helix from a strip of sheet metal that is preformed along one marginal portion thereof to provide a flange projecting to one side of said strip and that is preformed to provide a channel along the other marginal portion opening outwardly of the side of said strip opposite to said one side having a main body portion between said flange and channel, said head comprising:

(a) a pair of helically extending rods one spaced radially within the other a distance adapted to receive said strip along such flange thereby providing an inner rod and an outer rod;

(b) said rods defining substantially a single coil of a helix with the space between opposite terminating ends of said rods opening outwardly in generally opposite directions substantially tangentially of said helix,

(0) the adjacent surfaces of said rods being substantially cylindrical and one laterally facing surface of said outer rod directed axially of said helix and away from the body portion of said strip being free from obstruction to engagement with the side of said flange adjacent to said body portion when said strip adjacent to said flange is between said pair of rods,

((1) said rods being slightly offset relative to each other axially of said helix to engage said strip along the juncture between said flange and said strip and to bend said flange to follow a helical path upon moving said strip longitudinally thereof around said helix with said strip along the juncture between said flange and said strip disposed in the space between said rods.

4. In a machine for forming helical lock seam pipe from a continuous flat sheet metal strip;

(a) a pair of parallel rollers alongside each other between which said strip is adapted to be moved longitudinally of the latter,

(b) means supporting said rollers for frictional engagement with opposite sides of said strip between its marginal portions and for rotation of said rollers to so move said strip;

(c) an annular bending member on one end of one roller of said pair coaxial therewith and (d) an annular bending member on the end of the other member of said pair at the end thereof that is opposite to said one end,

(c) said means supporting said rollers for frictional engagement with opposite sides of said strip including shafts extending from one of the corresponding ends of said rollers,

(f) said bending members each being formed with an axially facing surface adapted to engage said strip along its opposite marginal portions for engaging and bending said marginal portions generally axially;

(g) each roller including a threaded end portion threadedly supporting each annular bending member on the roller carrying the same for axial movement to different adjusted positions on each roller relative to the portion of the roller that is adapted to engage opposite sides of said strip upon rotation of each annular bending member in one direction or the other relative to the roller carrying the same to thereby eflect a greater or lesser degree of bend of said marginal portions of said strip according to the gauge of the metal of said strip, and

(h) means for securing said annular members in their said adjusted positions for rotation with said rollers.

5. A construction as defined in claim 4, plus;

(i) the portions of said rollers that are adapted to frictionally engage the opposite sides of said strip being formed with annular axially spaced ridges in spaced staggered relation for so engaging said opposite sides of said sheet along axially spaced lines with the ridges on one roller of said pair in nonlapping relation, axially of said rollers, to the ridges on the other pair thereby enabling metal strips of different gauges to be driven by and between said rollers without changing the spacing between said pair of rollers and without material distortion of the flat portion of said strip between its marginal portions.

6. A machine for forming a helical lock seam pipe (a) a horizontally extending main frame;

(b) a plurality of pairs of horizontally disposed superposed strip-driving and marginal bending rollers horizontally spaced apart in a horizontally extending row adapted to receive a fiat strip at a feed end of said row and to drive said strip longitudinally thereof to the opposite helix forming end of said row;

(c) said rollers having marginal bending means thereon at their opposite ends adapted to form opposite marginal portions of said strip for interlocking when said strip is helically formed with one preformed marginal portion in lapping relation to the other preformed marginal portion,

(d) a helix forming head on said frame at said helix forming end of said row, said head comprising: (e) a pair of substantially parallel rods bent to form a single helix with one rod generally spaced radially inwardly of the other rod a sufficient distance to receive therebetween the portion of said sheet along one of said marginal portions only and said other rod being adapted to engage and to guide one of said preformed marginal portions around the helix formed by said rods to said position in lapping rela tion to the other marginal portion,

(f) means removably supporting said pair of rods on said frame in a position relative to the pair of said rollers adjacent thereto for receiving in said space at one of the ends of said pair of rods said one of said preformed marginal portions;

(g) a pair of presser rollers supported on said frame for rotation about an axis parallel with the axes of the rollers of said row and at right angles to the longitudinal axis of said strip,

(h) said pair of presser rollers being supported on said frame adjacent to the said helix forming head in a position for receiving the lapping marginal por tions of said strip therebetween and means supporting them for pressing said preformed lapping marginal portions in tight interlocked relation,

(i) a subfrarne below said main frame,

(3') and a pivot connecting said main frame with said subframe on a line extending perpendicular to the axes of said presser rollers and extending through said last mentioned axes and the preformed lapping marginal portions of said strip Where said pressing rollers force said preformed lapping marginal portions together.

7. A machine as defined in claim 6;

(k) coil supporting means on said frame for supporting a supply of said strip in the form of a coil thereof at the side of said pivot opposite to the side on which said row of rollers are positioned whereby the weight of said coil will partially balance the weight of said rollers to facilitatepivotal movement of said frame on said subframe;

(l) and guide means at the feed end of said machine for guiding said strip from a coil on said coil supporting means to the pair of rollers at the feed end of the row thereof and for supporting the portion of said strip between said coil supporting means and said last mentioned pair of rollers.

8. A machine for forming a helical lock seam pipe from a continuous sheet metal strip that comprises the combination of:

(a) a horizontally elongated main frame;

((1) a helix forming head on said frame at said helix forming end of said row adapted to receive and to guide one of said preformed marginal portions in a helical path to said lapping relation to the other preformed marginal portion,

(e) means on said frame below said helix forming head for pressing said preformed lapping marginal portions into interlocking relation,

(f) a portion of said frame extending longitudinally thereof past said helix forming head to the side of said head that is opposite to said row of rollers,

(g) a coil supporting roller having annular radially outwardly projecting heads at its end rotatably carried on said extension for rotation about a horizontal axis for supporting a supply of said strip in the form of a coil having a relatively large diameter central core; with the central axis of such coil spaced below the axis of said coil supporting roller,

(h) a pair of concentric marginal supporting wheels rotatably supported on said frame adjacent to the feed end of said row over which a length of such strip from the lower side of a coil adapted to be supported on said coil supporting roller is adapted to extend with the marginal portions of such strip extending around and over said wheels to between the rollers at the feed end of said row whereby the length of such strip adapted to extend between such coil and the feed end of said row will form a U- bend in passing over said marginal supporting wheels to relieve tension in said length prior to bending by such bending means.

9. In the combination as defined in claim 8,

(i) means supporting one of said marginal supporting wheels for movement toward the other to adapt said wheels to support a strip of reduced width, and

(j) an annular ring of an internal diameter greater than the diameter of said one of said heads adapted to be slipped over said one of said heads and onto said coil supporting roller without removing said roller for adapting said coil supporting roller to a coil of a metal strip of said reduced width.

10. In a machine for forming helical lock seam pipe from a continuous sheet metal strip and which machine includes a frame supporting means to preform opposite marginal portions of said strip to the same side of said strip for interlocking when said strip is helically formed with one preformed marginal portion in overlying relation to the other,

(a) a helix forming head on said frame in a position to receive said one of said preformed marginal portions upon movement of said strip thereto longitudinally of said strip and to guide said one of said preformed marginal portions to helical form and to interlocking relation with the other of said preformed marginal portions,

( b) flattening means on said frame adjacent to said helix forming head in a position to receive said preformed marginal portions after they are in interlocking relation, said flattening means comprising:

(0) a central roller and a pair of end rollers coaxial therewith, each rotatably supported on a shaft for rotation independently of the others about the axis of the latter, said central roller being of less external diameter than the external diameters of the two end rollers and said end rollers being of the same diameter,

(d) a drive roller supported on said frame for rotamovement of said strip longitudinally thereof thereby causing said strip including said flange and said channel to form a helix at said helical path;

() leaving the remainder of said strip extending transversely of said strip away from said flange and the portion adjacent thereto, free from all support and engagement with any external object other than along said flange, during said movement of said flange along said helical path, and

(d) guiding said leading end of said flange into said channel at the end of said helical path in the direction of movement of said flange, into said channel for securement therein.

pressed together in looking relation when the portions of the adjacent sections of said strip at opposite sides of the interlocking marginal portions are flat between the peripheries of said end rollers and said drive roller,

(e) said drive roller being adapted to be positioned inside the helix of said strip whereby the entire seam 15 will :be outside the inner surface of the pipe thereby leaving the inner surface of said pipe free from pro- References Cited by the Examiner UNITED STATES PATENTS jecfions 183,328 10/1876 Root 113-35 199,631 1/1878 Felix et a1. 24273 T method of g a hehcal, 10ck Seam P P 1 394 11 10 1921 Rendano 113 35 from a continuous strip of sheet metal moving longitu- 1856151 5/1932 B1 OS t a] 153 73 dinally thereof in one direction along -a path of travel s e n 2,03 8,483 4/ 1936 Ferguson et al 113-35 with one end leading, that includes the steps of.

(a) bending one longitudinally extending margina 2136942 11/1938 Freeze 11335 ortion of said stri to one side thereof to form a 2282176 5/1942 Fay et a1 11335 ontinuous flange, commencing with said leading g end and, at the same time bending the other lonme en u gitudinally extending marginal portion of said strip FOREIGN PATENTS to form a continuous channel openlng outwardly of 2 said strip to the side of the latter that is opposite to 41513 1 189 3 Great i i Said flange; 869,390 5/ 1961 Great Britain.

(b) confining the portion of said strip along said flange only, commencing with said leading end, to between helically extending surfaces defining the sides of a predetermined helical path of travel during said CHARLES W. LANHAM, Primary Examiner.

NEDWIN BERGER, Examiner,

Claims

1. IN A MACHINE FOR FORMING HELICAL LOCK SEAM PIPE FROM A CONTINUOUS SHEET METAL STRIP AND WHICH MACHINE INCLUDES: (A) A STRIP MOVING MEANS FOR MOVING SAID STRIP GENERALLY HORIZONTALLY LONGITUDINALLY THEREOF IN ONE DIRECTION, AND (B) FLANGE FORMING MEANS FOR FORMING A DOWNWARDLY PROJECTING FLANGE ALONG ONE MARGINAL PORTION OF SAID STRIP DURING SAID MOVEMENT, AND (C) CHANNEL FORMING MEANS FOR A UPWARDLY OPENING CHANNEL ALONG THE OTHER MARGINAL PORTION OF SAID STRIP DURING SAID MOVEMENT, WHICH CHANNEL IS ADAPTED TO RECEIVE SAID FLANGE THEREIN WHEN SAID STRIP IS HELICALLY FORMED; (D) A PAIR OF HELICALLY EXTENDING ROD ONE SPACED RADIALLY WITHIN THE OTHER TO PROVIDE AN INNER HELICAL ROD AND AN OUTER HELICAL ROD; (E) SAID RODS DEFINING SUBSTANTIALLY A SINGLE COIL OF A HELIX ABOUT A HORIZONTAL AXIS WITH THEIR TERMINATING ENDS LOWERMOST AND AT POINTS SPACED HORIZONTALLY APART A DISTANCE SUBSTANTIALLY EQUAL TO THE DISTANCE BETWEEN SAID FLANGE AND CHANNEL; (F) THE SPACE BETWEEN SAID RODS OPENING OPPOSITELY OUTWARDLY AT THE TERMINATING ENDS OF SAID HELIX; AND (G) MEANS SUPPORTING SAID HELIX OF RODS WITH ITS AXIS ABOVE THE PATH OF TRAVEL OF SAID STRIP AND AT RIGHT ANGLES TO THE DIRECTION OF MOVEMENT OF THE LATTER AND WITH OUTWARDLY OPENING SPACE BETWEEN SAID RODS AT ONE END OF SAID PAIR THEREOF FACING OPPOSITELY TO THE DIRECTION OF MOVEMENT OF SAID STRIP AND STUBSTANTIALLY IN ALIGNMENT WITH SAID FLANGE FOR RECEIVING THE PORTION OF SAID STRIP ALONG SAID FLANGE BETWEEN SAID RODS, AND WITH THE OUTWARDLY OPENING SPACE BETWEEN SAID RODS AT THEIR OPPOSITE ENDS FACING THE DIRECTION OF MOVEMENT OF SAID STRIP AND ADJACENT TO AND OVER THE SAID CHANNEL, (H) SAID OUTER HELICAL ROD BEING SLIGHTLY OFFSET RELATIVE TO SAID INNER HELICAL ROD AXIALLY OF THE HELIX AT SAID ONE END OF SAID PAIR OF RODS TOWARD THE EDGE OF SAID STRIP HAVING THE CHANNEL THEREIN TO SUPPORT THE JUNCTURE BETWEEN SAID FLANGE AND SAID STRIP AGAINST SAID INNER HELICAL MEMBER FOR FLOWING THE SAID INNER HELICAL MEMBER TO THEREBY FORM SAID FLANGE INTO A HELIX AND TO GUIDE THE LATTER INTO THE OPEN SIDE OF SAID CHANNEL DURING SAID MOVEMENT OF SAID STRIP.