US2145244A

US2145244A - Process of making reinforced tubes or pipes

Info

Publication number: US2145244A
Application number: US63896A
Authority: US
Inventors: Alfred J Berg; John O Huse
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-02-14
Filing date: 1936-02-14
Publication date: 1939-01-31
Anticipated expiration: 1956-01-31

Description

1939. A. J. BERG ET AL 2,145,244

PROCESS OF MAKING REINFORCED TUBES' OR PIPES Filed Feb. 14, 1936 E/5% J Bea BY Jan 0. 2/05:-

ATTORNEY Patented Jan. 31, 1939 UNITED STATES PROCESS OF MAKING REINFORCED TUBES OR PIPES Alfred J. Berg and John 0. Huse, United States Navy, Portsmouth, N. H.

Application February 14, 1936, Serial No. 63,896

1 Claim.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) Our invention relates to a reinforced pipe or tube and the method of producing the same.

The object of our invention is to provide a. reinforced pipe or tube with a reinforcement which shall not impair in any respect the strength, resistance to pressure, corrosion and other deterioration that may be encountered in use, and

which will increase the efficiency of the pipe or tube to which the same may be applied and at a moderate cost of production.

The further object of our invention is to provide the reinforcement of such character and structure that the same may conform to the foregoing objects.

A further object of our invention is to provide a process for the convenient commercial economical production of the reinforced pipe or tube in accordance with our invention, and which method may be practiced by hand or by any of a number of different machines with or without substantial modification.

Further objects will become apparent from familiarity with the specification. 4

In the drawing in which like characters of reference indicate the same parts,

Fig. l is a plan view of a portion of a tube constructed in accordance with our invention;

Fig. 2 is a magnified cross-sectional view of a portion of our reinforced tube;

Fig. 3 is a view similar to Fig. 2 but showing a foot in both sides of the reinforcing strip at its inner edge.

Fig. 4 is an illustration in central vertical sectional elevation of a means for performing the act of splitting the edge of the reinforcing strip adjacent to the pipe or tube.

In the drawing, I0 represents the pipe, tube, or other hollow body to be reinforced, and II represents the reinforcing strip. The reinforcing strip is formed usually from a flat thin wide strip of metal whose edge adjacent the pipe or tube is slightly turned over to form a shoulder in contact with the exterior surface of the tube. Such turned over edge is at its end secured to the surface of the tube by solder to a slight extent. The amount turned over at the inner edge of the fin is but a very small portion of the width of the initial fiat reinforcing strip. This bent over shoulder is progressively formedon the inner edge of the reinforcing strip II simultaneously with and in advance of the point where the flat fin II is progressively bent about the tube or other hollow member. This bent over portion of the reinforcing strip precludes the wrinkling of the reinforcing strip at its inner edge as it is being coiled about the pipe or tube, and further tends to reduce the liability of the formation of such wrinkles by slightly reducing the internal diameter of the bent or formed reinforcing strip; stiffens the inner edge of the reinforcing strip so as to tend to preclude the formation of wrinkles therein by reason of and during the bending operation and requires, for the avoidance of suchtwrinkles, that the neutral axis of the reinforcing strip while the same is being formed about the pipe or tubeshall be located longitudinally close to the bent portion I2 of said strip II. Relative to said neutral axis there will occur in strip I I, while the same is being formed about the pipe or tube, a compression strain in the metal of this strip II toward the surface of the tube ID from said neutral axis, while there will likewise occur in the metal of the strip I I an elongation or stretching stress between said neutral axis and the outer edge of the formed or bent strip II. This bent over shoulder I2 may be formed by at least one pair of rollers through which said edge of strip II is passed progressively adjacent to and while being wound upon the outer surface of pipe or tube ID. The pipe or tube I0 is not thinned or weakened by having formed therein any groove in which an edge of strip I I may be inserted and progressively wound therein and the wall of the pipe or tube I0 is not otherwise weakened. In the coiling or bending of strip II about the pipe or tube II] the bent edge or shoulder I2 of strip II .has a substantial tendency to induce the bending or winding of the strip II upright. However, some relatively slight lateral support is required for at least the outer edge of strip II at least at the point where it is being progressively bent or coiled about the pipe or tube III. The shoulder I2 of strip I I enables such reinforcment to be coiled about a relatively thin walled tube III without distorting or weakening such wall by the act of reinforcing such pipe or tube.

At a point preferably beyond the point where the strip II is being progressively bent the shoulder I 2 is rolled or thinned slightly and at least a portion of its area in contact with the tube III is depressed slightly into the outer surface of the thin wall of the pipe or tube I0 in order to secure the strip II to the wall of the pipe or tube III by an interrupted or continuous line of such depression or interlocking of the metal of the strip and the tube together extending parallel with the strip II and within the area of the shoulder I2.

Instead of forming the shoulder I2 solely upon .edge of strip I I.

one side of the strip I I while the sameis being formed or bent about the tube I0, shoulders I2a may be formed on opposite sides of the inner One convenient and inexpensive manner of forming said opposite extending shoulders I2a being shown in Fig. 4 in which the straight strip II is passed through a block or roller I5 having a slot extending therethrough provided with a flaring outer edge, and into which flaring edge enters the bifurcating edge of a knife or roller I6 which bifurcates the adjacent edge of strip I I without the loss of any metal content of the portion of the strip II which is so bifurcated. This operation is performed preferably continuously with and in advance of the coiling of this strip about the tube. The force required to coil the strip about the tube will spread said bifurcation and laterally extend the shoulders [2a from opposite sides of strip II during the coiling of strip II about the tube. This lateral extending of shoulders I2a, while the strip II is being pressed toward the body portion I0 exerts an abrading action upon and along the outer surface of the body portion in contact with the separated split edges of the shoulders I2a. This abrading action afiords a very efficient heat and cold exchange between the body portion III and the split surfaces of the shoulders or feet In of the strip II by providing a firm contact between clean metal freed from oxide or other accumulated matter, as well as avoids the possibility of inviting corrosion between the thus contacted surfaces. At a point subsequent to but continuous with the bending of the strip II about the tube the shoulders I2a are rolled or otherwise formed into the desired shape and preferably as a part of said shaping or rolling at least a small portion of the surfaces of shoulders I2a is depressed beneath the exterior surface of pipe or tube III to secure the strip to the tube by the interlocking together of portions of the metal of each of these secured parts in a course substantially continuous along the line of contact between said parts.

From the foregoing, those skilled in the art will be enabled to readily make the thus described reinforced pipe and to understand and practice the method of making the same, by hand, as well as by a number of different machines with or without substantial modification after becoming familiar with the foregoing.

It will be understood from the foregoing that a very eilicient reinforced pipe or tube is readily produced in accordance with our invention of the requisite strength and yet substantially lesser weight and cost more advantageously than has been possible to obtain with prior constructions.

It will be furthermore understood that the inherent advantages of the reinforced pipe or tube constructed in accordance with our invention is peculiarly adapted to be very advantageously employed for any purpose for which reiriforced'pipe or tubes may be employed as well as for the exchanging of heat and cold, among other uses. In such latter use the contact between the exterior and normal surface of the pipe or tube and the inner surface of the shoulder I2, as well as shoulders Ila, afford a very eflicient heat and cold exchange between the tube I0 and strip II; that the rolling and securing by said interlocking of the metal of the shoulder or shoulders and of thetube increases the rate of heat and cold exchange between the tube and the strip by increasing the density of the metal in the original of the surface of the parts in contact; that it provides a securement without any open joint in which dust, sediment or other non-conducting matter may be.deposited to impair the rate of heat or cold exchange between the parts thus secured together, as well as avoids the possibility of inviting corrosion.

This invention may be made and used by or for the Government of the United States for governmental purposes without the payment of any royalty therefor.

Having now so fully described our invention that others may therefrom make and use the same, what we claim is:

The method of making a heat exchanging element comprising the steps of splitting and partially spreading one edge of a thin rib, disposing said rib along a surface of the thin walled body portion of the element with said split edge of the rib in contact with the surface of the body portion, pressing the rib toward and along said body portion with its split spread edges laterally abrading the surface of the body portion as the same are further spread by said pressing, and simultaneously placing the 'outer and inner portions of said rib respectively under tensional and compressional stresses, slightly thinning said split edges and further spreading the same, and pressing a minor portion of said thinned edges beneath the normal surface of the thin walled body portion.

ALFRED J. BERG. JOHN O. HUSE.