US2685306A

US2685306A - Air tube

Info

Publication number: US2685306A
Application number: US200038A
Authority: US
Inventors: Tillman F Jones
Original assignee: Coleman Co Inc
Current assignee: Coleman Co Inc
Priority date: 1950-12-09
Filing date: 1950-12-09
Publication date: 1954-08-03
Anticipated expiration: 1971-08-03

Description

Aug. 3, 1954 'r. F. JONES 2,685,306

. AIR TUBE Filed Dec. 9, 1950 IN V EN TOR.

I ATTOHNE Y5.

Patented Aug. 3, 1954 AIR TUBE Tillman F. Jones, Wichita, Kans., assignor to The Coleman Company, Inc., Wichita, Kans., a corporation of Kansas Application December 9, 1950, Serial No. 200,038

3 Claims.

This invention relates to an air tube and to the method of forming the same. The invention is particularly useful in connection with a pipe employed for conveying heated air or conditioned air and in which the pipe is formed from sheet metal rolled into cylindrical shape.

In the manufacture of pipe commonly used with hot air systems, sheets of metal are rolled into cylindrical form and the edges of the metal are bent back and interlocked, the interlocked seam being usually swaged to secure the edges of the pipe together. The resulting pipe is not truly round and in securing the pipe sections together considerable difiiculty is often experienced in uniting the pipe sections, while often loose or unsatisfactory connections are made. Further, the pressure of the outside pipe upon the enclosed pipe often causes an undesirable slippage of the parts near their connecting edges. There has long been a need for a pipe section which could be inexpensively formed while at the same time providing an end having a true or uniform diameter which may be readily secured and clamped within the other or expandable end of the section. A substantial factor in the problem has been the requirement that little cost can be added to the pipe because so much of the pipe is required for an installation and the cost of the pipe enters largely into the cost of the complete installation.

An object of the present invention is to provide a pipe structure which overcomes the above disadvantages and permits ready assembly of the sections into a continuous pipe while preventing undesirable slippage of the interlocked edge portions of the sections. Yet another object is to provide a method for inexpensively forming pipe sections which permits the sections to be readily connected while forming uniformly tight joints. A still further object is to provide an air tube structure which may be formed quickly and at a minimum of cost While providing for the connection of the tubes readily and in a manner permitting the overlapping portions to be clamped tightly together. Other specific objects, and advantages will appear as the specification proceeds.

The invention is shown in an illustrative embodiment, by the accompanying drawing, in which- Figure l is a broken view in elevation of pipe sections embodying my invention, a portion of the structure being shown in section; Fig. 2, a broken top plan view; Fig. 3, an end view of a section; Fig. 4, a broken perspective View; and

Fig. 5, a detailed sectional view, the section being taken as indicated at line 5-5 of Fig. 2.

In the illustration given, l0 designates a pipe section which is formed from a sheet of metal rolled into cylindrical form and provided with interlocking edge portions H and t2, as illustrated in Fig. 5. At one end of the pipe, the pipe edges are brought into simple overlapping relation, as indicated at I3,,and that end of the pipe is adjusted by means of a jig so as to provide a slightly reduced end and the end is secured in this condition by a spotweld M or by other suitable means.

The lock seam [5 formed by the hooked edges II and I2 is preferably loose, permitting movement to increase or decrease the over-all diameter.

The end of the pipe opposite the seamed end is also provided with a slip seam in which one edge I6 ov laps the other edge I1. I prefer also to equip the latter or larger end of the pipe with a clamp [8 which has laterally extending integral strap portions l9 welded at 20 to the pipe on opposite sides of the slip seam. The clamp 18 is formed of malleable metal so that when the leg portions of the clamp are pressed towards each other they draw the overlapping portions of the pipe inwardly over each other and tighten the pipe about the enclosed pipe and the heavy or malleable metal cap I8 holds the parts in this position.

In the specific illustration shown, I provide a standard 3 /2" 0. D. and 28" length of pipe. It will be understood that any length may be employed and the diameter of the pipe may be varied as desired. By means of a jig and spotweld, the male end of the pipe is held to the proper dimension and secured therein while the opposite end is given flexibility by the use of the loose lock seam and by the slip seam at the end of the pipe. It will be understood, however, that this structure may be varied to give the desired flexibility.

Operation In the operation of the structure, a sheet metal strip is rolled upon itself to form the cylinder shown. The edges of the metal intermediate the pipe length are brought into interlocking position as illustrated at l l and I2. The ends of the pipe are provided with simple overlapping strips providing slip seams. The reduced end of the pipe is held to a desired smaller diameter by the use of a jig, and that end of the pipe is secured by spotwelding against further change.

The other end of the pipe is provided with a clamp for utilizing the flexibility of that end for clamping that end of the pipe readily about the reduced end of another pipe. Thus ready and accurate fitting is accomplished when the pipes are joined, by simple compressing of the clamp 48. In this operation, the reduced end which is spotwelded at 14 resists the compression caused by clamping the loose end of another pipe about it while at the same time providing a sturdy base about which the clamping is efiected. As a result, the uniting of pipe ends is accomplished easily and quickly, while at the same time permitting the ends to be clamped tightly against each other without the slipping of joints and While thus providing a tight seal. The forming of the pipe is accomplished at substantially no increased expense and in the resulting assembly of the pipe sections, a great saving in time and labor is brought about.

While in the foregoing specification, I have set forth a single structure in considerable detail for the purpose of illustrating an embodiment of the invention, it will be understood that the details of such structure and method may be varied widely by those skilled in the art without departing from the spirit of my invention.

1 claim:

1. An air tube, comprising a sheet of metal rolled into cylindrical form and provided intermediate its end portions with interlocking edges forming a pipe, said pipe at one end thereof being provided with overlapping portions providing a slip joint, and said end being reduced in diameter and spotwelded, the other end of said pipe being provided with a loose line of division permitting tightening of the pipe, and a clamp member having integral stra portions secured to said pipe on opposite sides of said line of division for normally maintaining said pipe end in enlarged condition for receiving the welded end of another pipe, said clamp being adapted to be compressed for tightening the loose end of the pipe about the reduced end of another pipe.

2. An air tube, comprising a sheet of metal rolled into cylindrical form and provided intermediate its end portions with interlocking edges forming a pipe, said pipe at one end thereof being provided with overlapping portions providing a slip joint, said end being reduced in diameter and rigidly secured, the other end of said pipe being provided with a loose line of division permitting tightening of the pipe, and a clamp member having integral strap portions secured to said pipe on opposite sides of said line of division for normally maintaining said pipe end in enlarged condition for receiving the reduced end or" another pipe, said clamp being adapted to be compressed for tightening the loose end of the pipe about the reduced end of another pipe.

3. In an air tube, a sheet of metal rolled into cylindrical form and provided intermediate its end portions with interlocking edges forming a pipe, said pipe at one end thereof being provided with overlapping portions providing a slip joint and said end being reduced in diameter and the overlapping portions secured together, the other end of said pipe being'provided with a loose line of division for tightening of the pipe, and a clamp member secured to said pipe at the loose line of division thereof for normally maintaining the pipe end in condition for receiving the reduced end of a similar pipe, said clamp being adapted to draw the loose end of the pipe about the reduced end of another pipe.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 539,334 Barclay May 18, 1895 942,256 Hague Dec. '7, 1909 2,463,593 Boardman Mar. 8, 1949 2,483,412 Harker Oct. 4, 1949