US1025337A - Manufacture of steam-boilers. - Google Patents

Description

H. H. TRACY & H. E. BOYRIE.

MANUFACTURE OF STEAM BOILERS.

APPLICATION FILED MAY 2, 1911.

1,025,337. Pat ented m 7, 1912.

al I d2 }w K i J a! J 'I 1 I G i I l O G (D H Q m M/OMOT D UNITED STATES PALIENT OFFICE.

HAYDEN HOMER TRACY, OF BERKELEY, AND HARRY EUGENE BOYRIE, OF SAN FRANCISCO, CALIFORNIA.

MANUFACTURE OF STEAM-BOILERS.

To all whom it may concern."

Be it known that we, HAYDEN HOMER TRACY, a citizen of the United States, and resident of the city of Berkeley, in the county of Alameda and State of California, and HARRY EUGENE BoYRIE, a citizen of the United States, and resident of the city of San Francisco, in the county of San Francisco and State of California, have jointly invented a certain new and useful Improvement in the Manufacture of Steam-Boilers, of which the following is a specification.

This invention relates generally to cylindrical boilers, or drums, of sheet metal designed for water and steam circulation,and particularly to those boilers or drums where the main joints are longitudinal, and in which a plurality of perforations must be made close together at some particular por tion or portions of the circumference for the reception of tubes.

The main objects of the improvement are to insure the maximum economy in material and labor, combined with the greatest efficiency in strength and durability, as well as convenience in manufacture and use.

A special purpose is to compensate for the weakening of the boiler or drum caused by the tube-openings at those parts which so often have to sustain the greatest load or strain. I

A further object is to present an integral structure with an evenly-continuous inner surface in place of those constructions where lapped seams or edges joined by rivets, are employed, with the necessary objection that the radius of the interior face of such styles of boilers is not uniform, and difliculty in consequence is experienced in fitting the required cylindrically-flanged heads or caps thereto, as in the case of steam and water drums for water-tube boilers.

A further and important object of the invention is to economize in weight of metal, it having been demonstrated that by doing away with overlapped meeting edges, and butt-joints, and the rivets heretofore found necessary in all of such structures, a saving in weight and cost of material alone of about one-half is effected.

To these ends, the invention contemplates-as an essential featurethe welding of the meeting edges of the metal composing the boiler or drum shell, by any of the approved methods, or processes, such as by Specification of Letters Patent.

Application filed May 2, 1911.

Patented May *7, 1912.

Serial No. 624,571.

electricity, or by acetylene or other gases capable of producing intense welding heat. (From this feature alone, the weakening of the structure caused by drilling for rivets at or near the seams, which invariably results from the practices now in vogue, is entirely obviated, whether the lapped joints have been narrow or otherwise, or whether they are single, double or triple riveted in any of the forms now commonly used.) (It may be further explained that it is impossible to make a riveted joint with an eiiiciency of 100 per cent, owing to the loss of that part of the sheet body where the rivet holes have to be made. A welded joint,

however, we have found, can be made with.

an efliciency exceeding 100 per cent, as it can be built up thicker than the main sheet, and the joint then becomes one of the strongest parts of the structure instead of the weakest.)

Briefly speaking, the present invention consists in a structure involving a metal cylinder made from a plate with the meeting edges abutting one against th other, and welded, brazed, or fused in S1101 manner as to present a uniform continuous cylindrical surface interiorly, and at the same time be homogeneous exteriorly of the circumference,-such plate, however, being of two thicknesses or gages of material, the greater weight or thickness coming at the point-or at such portion of the circumferencewhere such metal may have to be drilled or perforated for the reception of water or steam tubes.

For more complete comprehension of the invention, reference may be had to the accompanying drawings forming part of this specification.

Figure l is a cross-section of a boiler or drum constructed according to our invention. Fig. 2 is a longitudinal vertical section. Fig. 3 is a diagrammatic plan of the sheet from which the improved cylinder is preferably made.

In said drawings similar letters of reference indicate like parts.

In carrying out our invention, we prefer to form the boiler plate A by rolling according to any approved method, it being essential that the sheet be of at least two different thicknesses, the main portion A of its area being the thinner and going to make up the body of the boiler or drum,

and the auxiliary portion A being preferably about double the thickness of the former, so as to thoroughly compensate for all weakness throughout that area Which is tapped by the multiple holes 6, b, for the tubes B.

It is preferred that one extremity or side edge of the rolled plate A shall be at one end or edge of the thick auxiliary portion A and that the free longitudinal edge of the thinner main body A shall be Welded thereto at that point, as indicated by the abnormally heavy lines V, in Figs. 1 and 2, but the exact location of this welded joint is arbitrary, so long as the special feature of doing entirely away with lapped or abutting riveted joints or seams is maintained, and a perfectly cylindrical contour be preserved in the interior of the finished boiler or drum.

For commercial reasons, involving the purchase in the general market, and use of standard sizes and gages of boiler plates, it is apparent that our invention will in no wise be departed from should the main sheet A and the auxiliary portion A of the boiler shell be welded at two points WV, as in Fig. 1.

It'will be seen that from the nature and simplicity of this improvement it has been rendered possible and practicable to practice and employ, in one structure of an integral nature, all of the valuable features surrounding the needed reinforcement of ordinarily-weakened boiler shells at the points where a plurality of tubes may have to enter same, to lessen weight of metal throughout, and also-to conveniently adopt and use a simple welding process for joining the meeting edges of the shell in lieu of the objectionable riveting methods,

the whole of the advantages herein set forth being accomplished at practically one-half the cost for material and labor, and the efiiciency and appearance of the finished boiler at the same time greatly enhanced.

hat we claim and desire to secure by Letters Patent is as follows:

1. The combination in a water tube boiler, of a cylindrical drum made from two cylindrical segments of differentthickness, which segments are welded along their contiguous edges to form a seamless drum, with the interior surfaces of the segments continuous and flush and in the same circumference, so that the inside of the drum is smooth, the thicker portion of said drum being perforated and designed to receive the tubes secured in said perforations.

2. The combination in a water tube boiler of a cylindrical drum which is of substantially the same thickness throughout its circumference except in that portion which is to receive the tubes; said tube-receiving portion being thicker and in the plane of the remainder of the boiler drum and united thereto by welding, so that the interior of the boiler drum is substantially Hush and of uniform diameter and with the thicker part in continuation with the thinner part and homogeneous therewith, and tubes piercing the thickened portion of the boiler drum, substantially as, andfor the purpose described.

In testimony whereof, we have signed in the presence of the two subscribing wit- Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G.

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