US1933279A

US1933279A - Tubing

Info

Publication number: US1933279A
Application number: US567321A
Authority: US
Inventors: Bert L Quarnstrom
Original assignee: Bundy Tubing Co
Current assignee: Bundy Tubing Co
Priority date: 1931-10-06
Filing date: 1931-10-06
Publication date: 1933-10-31
Anticipated expiration: 1950-10-31
Also published as: FR743584A

Description

Oct. '31, 1933. B, QUARNSTROM TUBING Filed Oct. 6, 1931 4 2 Sheets-Sheet 1 I INVENTORQ BERT L. QUARNSTROM A TTORNEYS 0 31, 193 B. L. QUARNSTRQM TUBING 2 Sheets-Sheet 2 Filed Oc t. 6, 1931 l NV EN TOR.

A TTORNEYS.

Patented Oct. 31, 1933 TUEEKNG Evert ll..- Quarnstrom, Grosse Pointe Park, Mich... assignor to Bandy Tubing Company, Detroit, Mich a corporation at Michigan Application October 6, i931.' Serial No. 567,321

% Claims.

This invention relates to tubing, and it has to do particularly with a tube of improved conmovement.

struction which is made from strip stock fashioned into tubular form and having'its edges united to form a strong and effective seam.

The invention is one which lends itself advantageously to the making of tube from strip stock wherein the strip stock is fashioned through 360 thus giving the tube a single ply wall. Accordingly, drawings showing a tube having a single ply wall are utilized for this disclosure, but it is understood that the invention is applicable to tubes having multi-ply walls.

A tube of a single ply wall constructed in accordance with the invention comprises a strip shaped into tubular form with its edges overlapping and secured together; this type of tube made from strip stock is commonly termed a lap seam tube. The object of the invention is to provide an improved lap seam structure wherein the edges are locked together. The structure is such as to materially strengthen the tube inasmuch as the locking arrangement prevents the edges from separating by relative movement circumferentially of the tube, and also by relative radial A number of things may tend to cause'such separation, such as pressures on the tube either internally or externally, or by the bending of the tube into suitable shapes. As a more specific example, high internal pressure may tend to separate the edges by relative, circumferential movement. In accordance with the invention the edges are locked together to oppose such movement. Prior to separation by relative circerential movement, relative radial movement of the edges may be necessary to permit oi relative circumferential movement, but in accordance with the invention the edges are locked together to prevent this relative radial movement.

In the accompanying drawings:

Fig. l is a transverse sectional view taken through a strip oi! stock showing the same as it may appear after the first operation in the making of the tube.

Figs. 2 to 6, inclusive, show one way in which the strip stock may be rolled or fashioned into tubeiorm by means of suitable forming rolls known in the tube making art.

Fig. 7 is an enlarged sectional view taken through the edges prior to the final operation.

Fig. 8 is an enlarged sectional view showing the completed lapped and locked seam.

Fig. 9 is a sectional view in illustration of (Gi. Hal- 35 forming rollers which may be used for suitably shaping a strip into the form shown in Fig. i.

Fig. 10 is a sectional view illustrating rollers and arbor which may be employed in making the tube just prior to the final operation.

Fig. 11 isa similar view illustrating rollers and arbor which may be employed in the final opera tion.

A strip of material, of which the tube may be made, may be, in a long length and disposed in a roll from which'it may be drawn by longitudinal movement and fashioned and shaped into tube form by tube forming rollers such as are known in the tube making art. Such strip may be 0i uniform thickness from edge to edge, and the thicknessand width may be selected as desired for making tubes of diiierent requirements. The strip may be first acted upon to shape it substantially as shown in Fig. 1. This may be done by means of rolls, as shown in Fig. 9, wherein the strip is referenced 1 and opposed rolls are at 2 and 3.

These forming rolls may be termed pressure rolls between which the strip may be drawn. The space between the rolls in their central portions may be such as to be substantially equal to the thickness of the stock; the roll 2 may have a fillet 4, a groove 5, a raised portion 6, and a part 7 the diameter of which may be slightly greater than the central portion of the roll. Roll 3 may have corresponding parts such as fillet 8, groove 9, raised portion 10 and part 11. As the strip passes through these rolls the said parts cooperate to flow the metal of the strip and shape the same, as shown in Fig. 1. The 99 raised portions 6 and 10 compress and flow the metal to form grooves near the edges of the strip, as shown at 15 and at 16. In doing this the metal is compressed and some of the same fiows into the grooves 5 and 9 thus forming projections 1'! and 18 immediately adiacent the

grooves

15 and 18. The parts 7 and 11 of the rolls may compress the extreme edges of the stock thus thinning them and forming

parts

19 and 20,

while the fillets 4 and 8 form angular or beveled

10o edges

21 and 22. In thus shaping the strip it is preferable that the thickness of the metal forming the bottom of one of the grooves plus the thickness of the metal forming one of the

edge portions

19 and 20, is substantially equal to the initial thickness of the strip stock, or in other words, equal to the center or body portion of the strip.

After thus fashioning the strip the same may then pass through the forming rolls of a tube lit) .of the strip following the second bending operation; Fig. 4 illustrates the shape the strip may take following the third bending operation; Fig. 5 illustrates the relation of the parts of the strip and the shape of the strip following the fourth bending operation; while Fig. 6 may illustrate the final form of the tube. Inasmuch as the tube making machines embodying tube forming rollers are known in the art it is not deemed nee-v essary herein to show such machine as the manner in which tube is constructed by the machines is well known to those versed in the art.

By referring to Fig. '7, it will be noted that the portion 19 is fitted into the groove 16 whereas portion 20 is fitted into the groove 15. Advantageously and preferably the formation of the strip is such that the inner edge of the portion 19 and inner edge of the portion 20 are substantially at right angles to the body of the strip so that these two edges form an effective engagement with each other when they are fitted together as shown in Fig. 7. It is advantageous that the

parts

19 and 20 fit rather snugly in the

grooves

16 and 15 when in the condition shown in Fig. 17. The engagement may be rendered still more snug or tight after pressure has been applied for finally shaping the partsas shown in Fig. 8 by means of flowing the metal. It will be noted thatthe beveled edge 22 lies next adjacent projection 18, and the bevel edge 21 lies next adjacent the projection 1'7. These

projections

17 and 18 are then urged or fashioned against the respective beveled edges substantially filling the groove formed thereby, and'due to their overlapping the beveled edges, serve to lock the parts togetherto prevent separation of the overlapped edges of the strip by relative radial movement. In Fig. 10 a pair of rolls and an arbor are shown such as may be employed when the tube and its seam are in the condition shown in Fig. 7. The pressure rolls are illustrated at 30 and 31, respectively, one of which has a groove 32 for accommodating the projection 18. Inside the tube is an arbor 33 having a groove 34 for accommodating the projection '17. In Fig. 11 there is shown another set of rolls and another portion of the same arbor 33 such as may be employed for fashioning the

projections

17 and 18 into locking position. These rolls are shown at 35 and 36, respectively, and are shaped to engage the tube structure over its surface while the arbor 33 at this point does not have the groove 3i.v Thus the arbor fashions the projection 17 into its final position, and the roll 35 fashions the projections 18 into final position as the tube is drawn or moves through rolls and over the arbor. It is to be appreciated that the

rolls

35 and 36 may exert considerable pressure upon the tube and that the arbor provides internal reinforcement, exerting requisite outer pressure for shaping the projection 17 and for supporting the tube.

It will be seen that a tube thus constructed has a seam wherein the edges are lapped, and at the same time locked together. An eflective lock is provided by the interfitting of the

projections

19 and 20 and the

grooves

15 and 17. To further strengthen this lock and to prevent separation of the edges,

projections

17 and 18 are thrown down over opposite edges of the stock. By coordinating. the depth of the

grooves

15 and 16 and the meagre thickness of the

portions

19 and 20 the wall thickness of the tube at the seam may be substantially equal to the stock thickness. When the

portions

17 and 18 are fashioned into final position both the inside and outside surfaces of the tube are completed into a smooth substantially unbroken surface.

Various kinds of metals may be selected in making this tube, and the seam may be sealed by the utilization of molten sealing metal of any desirable type. Also the edges of the strip may be welded without the use of an intermediate sealing metal. The seam and all overlapping parts may be sealed by the means of solder such as the common tin and lead alloy, or various other solders such as silver-solder or the like, or brazing metal. Copper may be used for sealing the seam as well as for coating the tube inside, outside, or both, and in this regard it may be pointed out that the copper sealing and coating medium may be employed with strip stock of ferrous metal. Of course the copper may be employed with strip stock of other metals, but where ferrous metal is used it may be desirable to coat the same and seal the seam with copper. It may also be pointed out that while the strip for forming the tube herein described is fashioned into appropriate form by pressure rolls, as illustrated in Fig. 9, the strip may likewise be fashioned by cutting or trimming operations without departing from the scope of the invention. The resultant tube is one having a strong, single .ply wall with a seam which afiords substantiallyunbroken and smooth interior and exterior tube surfaces, and which aifords great strength for resisting rupture or breakage. While it is preferable that the seam be sealed by molten metal or by welding for the purpose of conducting fluids or the like, structural tubing may be made and used without sealing the seam against fluid leakage as the seam structure affords material strength even without being thus sealed.

I claim:

1. A tube comprising a strip of metal fashioned into hollow cross sectional form with the edges 1;?

of the strip overlapping and providing a seam lengthwise of the tube, each edge having a groove and an adjacent projecting portion, with the grooves and projecting portions of the respective edges interlocking with each other, and means on an edge overlapping the other edge for locking the edges against separation by relative radial movement.

2. A tube comprising a strip of metal fashioned into hollow cross sectional form with the edges of the strip overlapping and providing a seam lengthwise of the tube, each edge having a groove and an adjacent projecting portion with the grooves and projecting portions of the respective edges interlocking with each other, each edge having another projecting portion overlapping the opposing edge for locking the edges against separation by relative radial movement.

.3. A tube having a longitudinally running seam comprising a strip of metal fashioned into hollow cross sectional form with the edges of the strip overlapped, one on the inside and one on the outside, said edges having cooperating grooves and projections which interflt to form a locking engagement, the edge of the strip on the inside of the overlap having a part which overlaps the outside of the opposite edge.

4. A tube comprising a strip of metal fashioned into hollow cross sectional form with the edges of the strip overlapped, one on the inside and one on metal of the edge forming an abutment defining the outside, said edges having cooperatin grooves and projections which interfit to form a locking engagement, theedge of the strip on the inside of the overlap having a part which overlaps the outside of the opposite edge, and the edge of the strip on the outside of the overlap having a part which overlaps the opposite edge on the inside of the tube.

5. A tube comprising a strip of metal fashioned into hollow cross sectional form with the edges overlapping, each edge having a longitudinal groove bounded by an abutment with said grooves and abutments interfitting to lock the edges together, the edge of the stock located inside the tube having a longitudinal part disposed so as to overlap a portion of the opposite edge on the outside of the tube, and the edge of the stock located outside the tube having a longitudinal part disposed so as to overlap the opposite edge of the stock on the inside of the tube..

6. A tube having a longitudinally running seam comprising a strip of stock fashioned into hollow cross sectional form with its edges overlapping, said edges having interfitting grooves and projecting portions to lock them together against separation by relative circumferential movement, said edges at their extreme ends having each a beveled portion, and each edge having a longitudinal projection fashioned into overlapping relation as regards the beveled portions.

7. A tube comprising a single strip of metal stock fashioned into hollow cross-sectional form having a longitudinally running seam, one face of the stock having a longitudinally running groove adjacent one edge of the stock with the one side of the groove, the metal defining the opposite side of the groove having a longitudinally running projection, the opposite face of the stock having, adjacent the opposite edge of the stock, a similar groove defining abutment and longitudinally running projection, the edges of the stock being lapped one over the other with the abutment forming metal of each edge fitted into the groove of the other edge,and the longitudinally running projections overlying portions of the edges fitting into said grooves to lock the same in the grooves.

8. A tube comprising a single strip of metal stock fashioned into hollow cross-sectional form having a longitudinally running seam, one face of the stock having a longitudinally running groove adjacent one edge of the stock with the metal of the edge forming an abutment defining one side of the groove, the metal defining the opposite side of the groove having a longitudinally running projection, the opposite .face of the stock having, adjacent the opposite edge of the stock, a similar groove defining abutment and longitudinally running projection, the edges of the stock being lapped one over the other with the abut ment forming metal of each edge fitted into the groove of the other edge, the e rtreme edgesof the stock being. relieved from opposite faces of the stock and the longitudinally running projecspective relieved portions of opposite edges to lock the same in the grooves.

BERT L. QUARNSTROM.

tions adjacent'the said grooves overlying the re-