US24323A - Truss for roofs - Google Patents

Description

UNITED STATES PATENT OFFICE.

M. C. MEIGS, OFy WASHINGTON, DISTRICT OF COLUMBIA,y AND SAMUEL J. REEVES, F

PHILADELPHIA, PENNSYLVANIA.

TRUSS FOR ROOFS, BRIDGES, &c.

Specification of Letters Patent No. 24,823', datedJune '7, 1859.

To all whom fit may concern:

Be it known that we, MONTGOMERY C. Mmes, of Washington, District of Columbia, and SAMUEL J. REEVES, .of Philadelphia, in the county of Philadelphia and State of Penn- Sylvania, have invented a new and Improved Truss or Frame for Roofs and Bridges; and we do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The nature of our invention consists in the use of tension rods or ties of metal wood or other suitable material'attached to various points of an arched or curved beam of metal or wood and converging to and connected together at a common point within the space included between the arched or curved beam and the greatest chord of the are, the straight line joining its two extremities.

To enable others skilled in the art to make aud use our invention we will proceed to describe its construction and operation as shown upon the accompanying drawing, which represents two trusses or roof frames designed the one for a span of one hundred and fifty and the other for a span of one hundred feet.

Figure l represents a truss of a span of one hundred feet. a, d, e, f, g, 71 represents the curved or arched beam of wood or metal of suitable dimensions to which at the points a, CZ, @,f, g, and h, are attached tension rods or ties a, de, ec, fc, g, he, and bc,

of metal, wood or other suitable material which converge to the central point c, between the arched or curved beam and the straight line, ab, where they are strongly connected together either immediately or by the use of a connecting ring or plates or other suitable means.

Fig. 2 represents a truss of a span of one hundred and fifty feet. a, d, e, i, f, g, h, b, represents the arched or curved beam of wood or metal. ac, d, cc, z'c, f, g, he, and be, are the tension rods or ties of metal, wood or other suitable material which are all strongly attached to the curved or arched beam at their outer ends and converging to the point, c, between the arched or curved beam or rafter and the straight line a, b, joining its extremities are there strongly connected toeach other. In this design a chord or tie reaching from one end of the curved beam or rafter to the other is represented. This is not essential to our construction or invention which may be used in combination with this principal tie ror without it as may be more convenient and economical in the particular roof to be constructed. When this principal tie is omitted the arched or curved beam and some of the ties ac, be, &c. must be made stronger than when it is used.

By experimenting upon the model which accompanies this design and specification or by a mathematical investigation it will be seenthat any irregular load or load applied to and tending to force inward toward the center, or to depress any point as g of the arched or curved beam will tend to cause some other part as, e, to rise or recede from the center and this tendency is resisted by the tension of the tie as, ce, which corresponds to this part e. By the tension of the tie ec and of those adjoining the force or strain is transmitted to the point, c, which being by the lower ties ac, cb firmly connected with the fixed ends of the arched or curved beam or rafter. the tie e?, and those adjoining can not yield to the strain produced by the irregular load without stretching 0r breaking themselves or stretching or breaking one or both of the ties ac, cb, or lifting or removing the ends of the curved or arched beam or rafter from their positions. But as the tendency of the whole weight of the roof and of all loads equally or unequally distributed upon it is to more firmly fix the ends of the beams upon the walls, it is evident that these points may be regarded as Xed and immovable by any strains arising from loads not "able to break some part of the truss thus constructed. The same reasoning applies to any other points of the curved beam than and, e,

When they rest upon the walls and therefore the truss will be a stiff and n Fig. 3, represents a simple mode of con- Y necting the ties with the ends of the beam by means of bolts and shoes resting upon the wall.

Fig. 4, represents one mode of connecting vthe ends of the radiating ties where they meet at the point, c, by a ring passing through rings formed on the inner ends of the ties. Y

Fig. 5 represents a mode of connecting the outerV ends ofi-the ties or tension rods with the curved beam.

Having calculated the dimensions of th p' parts of trusses designed upon this princi'-A ple for various spans from 80 to 200 feet We lare able to say that the invention Will be an important contribution to the science of-` engineering and construction and that it is applicable with great eeonomy'toroofsof spans even exceeding 200 feet.

What We claim as our invention and desire toV secure by Letters Patent is- The inode of trussing or stilening a curved or arched beam or rater for bridges or roofs by means oftension rods or ties of metal, Wood or other suitable'material connected at their outer ends With the arched or curved beams or rafters at various points and `converging toward and connected together at their inner ends at a point Within the space" contained between the arc or arched or curved beam or rafter and the straight line joining its extremities `substantially as above described and as represented in the drawing and model herewith.

o. Mines. n l SAM J REEvEs.- p

VVit-nesses: Y Y

PAUL T. JONES, Jr., JNO. B. KENNEY.

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