US1725088A - Counduit - Google Patents

Description

A ug. 20, 1929. w. J. LEARY CONDUIT Original Filed March 3l, 1927 Dx by Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM J. LEARY, OF CHICAGO, ILLINOIS.

CONDUIT.

Application led March 31, 1927, Serial No. 180,047. Renewed January 17, 1929.

This invention relates to a conduit and more particularly to a fabricated conduit which is acid and alkali resistant and thereby enables the conduit to be used for conveying materials which would eat into ordinary piping and require its frequent replacement.

The principal object of this invention is to provide a conduit or pipe constructed of spirally wound strips of metal, the inner i strip or lining of which is of an acid and alkali resistant metal such as lead, Monel metal, brass, copper, tin, etc., and the outer strip or strips of which are of steel or, .if desired, a relatively hard and durable acid and alkali resistant metal such as Monel metal, brass, copper, tin, etc., theouter strips being securely interlocked .to impart the necessary strength and rigidity to the conduit, and the seam or joint between the convolutions of the lead lining being tightly and reliably sealed to insure against possible leakage ot' the material being conveyed to the exterior steel strips.

A further airn is to provide such a fabricated conduit which is adequately insulated to prevent exchange ot' heat between the lining ofthe conduit and the protecting sheath.

Further objects are to provide such piping which is light in weight, easily fabricated by continuous winding processes, and in which heavy gage'and hard sheet st eel can be employed for the layer which reinforces and supports the lining, thereby permitting of the production of large size piping of great strength.

ln the accompanying drawings: v

Figure 1 is a side elevation ola section length of a conduitmade in accordance with my invention, a portion of the same being shown in section. Figure 2 is an enlarged fragmentary oblique section taken transversely through the joint between the convolutions of the conduit shown -in Fig. 1. Figure 3 is a View similar to Fig. 1 but showing a modified form ot' joint. Figure 4 is an enlarged sectional view similar to Fig. 2 but showing the modified forni of joint illusti'ated in Fig. 3. Figure 5 is a view similar to Figs. 2 and 4, but showing a further modified form of joint. Figure 6 is a fragmentaiy longitudinal section through the form of locking band shown in Fig. 5. Figure 7 is a view partly in elevation similar to Fig. 5, but showing the same rolled and the attaching lugs struck out from the base thereof. Figure 8 is a perspective View of a section of the lead key which is interposed between the lead lining strip in all of the forms of the invention illustrated in the drawings.

Similar reference numerals refer to like parts on each of the several figures.

The strips of metal used in making the conduit may vary in Width or thickness and either a single strip of metal can be used as shown in the drawings, or a lurality of strips may be employed side y side, in which case the lead of the convolutions may be increased. Good practice dictates that a long spiral lead makes a much stronger and stiffer pipe than a short lead. Although a short lead may be used in Winding the strips it is preferable to make the leads as long as possible to avoid fracturing the met-al or destroying the fibrous structure thereof, which would be liable to occur if the metal were crimped or bent abruptly.

The lining of the conduct is made of a strip 10 of sheet lead or other soft acid and alkali resistant metal and is wound spirally on a mandrel. Simultaneously with the winding of the lining strip 10, a lead key 11 is wound so as to be interposed between the successive convolutions of the lining strip. This key as shown in Fig. 8 is in the form of a continuous band and the opposite sides thereof are recessed or dished inwardly as indicated at 12. When the key and lining strip are being wound, the key is fed against the advance edge of the lining strip so that a ange 13 is formed on the advance edge of the strip, which flange lies against the recessed side l2 of thekey, and the width of the strip being wound is proportioned so that a similar flange 14 is formed at the rear edge of the strip against the advance recessed face 12 of the next preceding convolution of the key strip. By this means both edges of the lining strip are extended along opposite sides of the key strip, as shown in Figs. 1-5, and a tight joint is obtainable.

To securely unite the lining strip and the key strip and also to impart the necessary strength and rigidity to the conduit, a metal strip 15 of steel or the like is wound helically over the lining strip and a locking band 16 is wound over the spiral joint and securely locks the convolutions together. This metal strip 15 is formed at its edges to provide flanges 17 which lie against the outer sides of the flanges 13 and 14 of the lead lining strip as best shown in Figs. 2, ,4, and 5. The

locking band 16 comprises a central portionV extending` flat flange 23 and the underside of the central portion 1S is provided with a rounded ridge 2e. Before being applied to the body of the conduit, the side portions 2O are spread apart and disposed at an oblique angle to the central portion 18. The band is then wound over the seam and the central portion thereof rolled down o n the upper ends of the flanges of the lining and steel strips, and at the same time the side portions are rolled flat against the periphery of the conduit, andthe inner ridges 22 thereof are forced under and against the flanges 17 and the seam thereby compressed so that the lead is forced to flow and unites the flanges and key. The locking band also provides a. joint which is as strong or stronger than the other portions of the conduit and stiffens and strengthens the entire piece of p1 Je.

lIo prevent circumferential displacement of the locking band and also to add to the strength and tightness of the joint, each of the steel strips15 is provided adjacent its two ,edges with a plurality of circular recesses suitably formed on the outer side of the strip and spaced the entire length of the same. The locking band 1G is similarly providedwith a plurality of lugs or bosses 25 spaced along the inner side of the flat flanges 23, which lugs are adapted to engage the corresponding recesses in the steel strip. These lugs 25 are preferably stamped or punched from the locking. band, leaving corresponding recesses 26, on the outer side thereof.

The insulation 27 is then wound on the conduit between the convolutions of the locking band. This insulation may be of any suitable material but is preferably acid and alkali resistant and is preferably wound in the form of a strip or sheet which completely fills the space between the convolutions of the locking band but leaves the channel 19 in the upper side of the locking band exposed.

In the next operation the sheath is wound over the insulated conduit to finish, strengthen and protect the pipe. This sheath is preferably made of a steel strip 28 and the adjacent edges'of the successive convolutions are interloclred about a core 29, but if it is desired to have a'conduit which is acid resistantboth inside and outside, it may be made of lead, brass, copper, etc. Different seams may be employed for this purpose, the seams shown in Figs 1 and 2 being formed about a round core and being of corresponding shape, and the seams shown in Figs. 3-5

being wound around a core which is recf tangular in cross section. In this latter form of seam, the edges of the strip are interloclred so that the seam is disposed on the inner side of the sheath thereby providing a conduit having a smooth outer surface. In each of the forms, the seam is received in the channel 19 provided in the locking band, thereby materially strengthening the pipe against bending strains. If desired, the seam formed by the interlocking of the edges of the sheath strip may be soldered or brazed to the locking band so as to prevent the sheath from separating when the pipe is .cut.

In the modified form of the invention shown in Figs. 5, 6, and 7, the central portion 18'of the locking band is provided with a series of integrally formed wedge shaped lugs or teeth 30 which are spaced along the inner side of the same. When the locking band is rolled, these wedges are forced into the lead key and causethe lead to flow laterally and upwardly and securely unite the members forming the seam and provide a hermetically sealed seam. These wedge shaped lugs or teeth also serve as spacers, the flanges 17 being forced against the sides of the teeth when the locking band is rolled in place, as shown in Fig. 5, and these teeth thereby insure a seam or joint of uniform width and strength throughout the conduit. Inasmuch as the conduit during this opera tion is held on a mandrel, the bore or inner surface ofthe conduit is not affected by this squeezing ofthe lead-in the seam.

This invention provides a light and inexpensive fabricated conduit for conveying acid and alkaline materials; it is strong and thoroughly insulated and adequately protected against injury.

I claim as my invention:

1. A conduit comprising a helically wound strip of a soft, acid resistant metal, a helically wound strip `of theV same metal arranged between adjacent convolutions of said first named strip, and means for locking said strips together.

2. A conduit comprising a helically wound strip of a soft, acid resistant'metal, a helically wound key of the same metal interposed between adjacent convolutions of said strip, said strip being formed at its edges to provide flanges arranged at the opposite sides of said key, and a helically wound locking band locking said flanges and key together.

3. A conduit comprising a helically wound strip of a soft, acid resistant metal, a helically wound key of the same metal interposed between adjacent convolutions of said lll) strip, said key having inwardly dished sides, and said strip being formed at its edges to provide flanges arranged at the opposite inwardly dished sides of' said key, and a helically wound locking band locking said flanges and key together.

4. A conduit comprising a helically wound lining strip of a soft, acid resistant metal, said lining being formed at its edges to provide flanges, a helically wound hard metal strip overlying said lining, said outer strip being formed to provide flanges arranged adjacent the flanges of said lining strip, and a helically Wound locking band engaging the outer sides of the flanges of said outer strip.

5. A conduit comprising a helically wound lining strip of a relatively soft, acid resistant metal, a helically wound key of the saine metal interposed between adjacent convolutions of said strip, said key having inwardly dished sides and said lining strip being formed at its edges to provide flanges arranged at t-he opposite inwardly dished sides of said key, a helically wound hard metal strip overlying said lining strip, said outer strip being formed to provide flanges arranged adjacent the flanges of said lining strip, and a helically wound locking band engaging the outer sides of the flanges of said outer strip.

6. In a conduit, a helically wound lining strip of relatively soft metal, a helically Wound key of the same metal interposed between adjacent convolutions of said strip, said lining strip being formed at its edges to provide flanges arranged at the opposite sides of said key, a helically wound hard metal strip overlying said lining strip, said lining strip being formed at its edges to provide flanges arranged adjacent the flanges of said lining strip, and a helically Wound locking band engaging the outer sides of the flanges of' said outer strip, said locking band being provided with an inwardly projecting portion which is forced into said key during winding of the conduit and uniting said key and lining.

7. In a conduit, a helically wound strip of relatively soft metal, a. helically wound key of the same metal interposed between adjacent convolutions of'said strip, and means for locking said strip and key together, said means including inwardly projecting portions which are forced into said key and unite said key and strip.

8. In a conduit, a helically wound lining strip of relatively soft metal, a helically wound key of the same metal interposed between adjacent convolutions of said strip, said lining strip being formed at its edges to provide flanges arranged at the opposite sides of said key, a helically wound hard metal strip overlying said lining strip, said lining strip being formed at its edges to provide flanges arranged adjacent the flanges of said lining strip, and a helically wound locking band engaging the outer sides of the flanges of said outer strip, said locking band being formed with a series of longitudinally disposed, wedge shaped teeth which are forced into said soft metal key during the winding of the conduit and unite said key and lining.

9. In a conduit, an inner helically Wound strip of metal, said strip being formed at its edges to provide flanges, a helically wound locking band engaging the opposite sides of said flanges and locking adjacent convolutions together, a helically wound insulating strip overlyin said inner helically wound strip, a helically wound strip overlying said insulating strip and said locking band and forming a sheath, the strip forming the sheath being interlocked at the edges of adjacent convolutions, and a seam thereby formed being received in a longitudinal channel provided in said locking band.

10. In a conduit, an inner helically wound strip of metal, said stri being formed at its edges to provide anges, a helically wound locking band engagin the opposite sides of said flan es and locing adjacent convolutions toget er, a helically wound insulating strip overlying said inner helically wound strip, a helically Wound strip overlying said insulating strip and said locking band and forming a sheath, the strip forming the sheath being interlocked at thel edges or" adjacent convolutions to form an inwardly extending seam which is received in a longitudinal channel provided in said locking band.

1l. In a conduit, an inner helically wound strip of metal, said strip being formed at its edges to provide flanges, a helically wound locking band engagin the opposite sides of said flanges and loc ing adjacent convolutions together, a helicaly Wound insulating strip overlying said inner helically wound strip, a helically wound strip overlying said insulating strip and said locking band and forming a sheath, the strip forming the sheath being interlocked at the edges of adjacent convolutions, and a sea-m thereby formed being received in a longitudinal channel provided in said locking band, said seam being adapted to be connected by a fused joint with said locking band.

In testimony whereof I affix my signature.

WILLIAM J. LEARY.

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