US513794A - Tension-rod - Google Patents

Description

- 2 shets-sheet 1'.

lTBNSIGN RGD. No. 513,794.I

Patented Jan. 30, 1894.

Wi'tnEsSES- `(No Model.) `A2 Sheets-Sheet 2.

' T.. A; LEB. TENSION ROD.

Witnessgs.. x M'SQW, A

"ma @.@Qwm Y NITED STATES APATENT EErcE.

` THOMAS A. LEE, or KANSAS CITY, MISSOURI.

TENSION-ROD.

SPECIFICATION forming part of Letters Patent No. 513,794, dated January 30, 1894.

Appnmio ned April 3o, 1892.

To @ZZ whom it may concern,.-

Be it known that I, THOMAS A. LEE, of Kansas City, in the State of Missouri, have invented certain new and useful Improvements in Tension-Rods for Fireproof Floors, Roofs, Ceilings, Valls, Cement Area-Walks, and the Like, of which the followingV is a description,

. reference being had to the accompanying rwstantially in the manner hereinafter described, illustrated, and claimed.

In the accompanying drawings, Figure lis an isometric projection showing oneform of my tension rod or cable embedded in a mass of plaster, concrete, or other building material. Fig. 2 is a similar view showing my tension rod as used in one construction of ooring. Figs. 3, 4, 5, 6, and '7,'are detailed views of several types of my tension rod or cable.

In the drawings like letters ot' reference indicate like parts.

In the construction vof my rods or. cables I preferably employ steel wire of high tensile strength which has been drawnthrough a die,

thus obtaining greater uniformity and relia-` bility with a much higher tensile strength and elastic limit than the usual rolled bars or rods possess. The wire is cut into convenient lengths for twisting-say fifty or seventy feet-and washers or separating devices hereinafter more fully described, are strung upon the wires or placed between several wires laid side by side, at desired intervals. The number of wires, preferably three or four, are then made fast to end clamps provided with tension attachments and means for twisting the wires and the cable. The wires are then twisted and the Awashers or spreaders thereby 5o bound rmly in position.

My washers or spreaders consist of metal blocks, plates, rings, or flat strips. These Serial No. 431,369. (No model.)

hold the wires apart at the points where they occur, and thereby greatly increase the cement engaging surface of the cable or rod. They also serve to hold the wires while being twisted and in certain types project above the rod and form anchor plates for more securely retaining the rods in their surrounding masses of cement.

In Fig. 4 I have'shown in sections and in side view a piece of tension rod provided with the washers L my most preferred form.

These consist of pratssn provided with perforations through which theeseyeral wires of the tension rod are strung.

Figs. 3 and 5 show my cables providedwith`` devices for merely spreading the wires apart and presenting cement engaging surfaces.

Fig. 6 shows my rod provided with plate strips forming spiral ribs around the rod. I

vprefer to cut these plate strips of lengths vequal to the wires to be twisted and of iron similar to thin hoop iron and possessing high tensile strength. Vhen placed between the wires as shown in the gure and twisted with them, these strips form a spiral rib between each pair of adjacent wires, giving great cement engaging surface and resistance to end stresses or thrusts. When the plate strips are made of metal possessing different coefficients of expansion with heat, I preferably cut the Strips into short lengths. In the use of these plate strips I am able to form tension rods of metals having dilferent coefficients, without injury Vto the floor structure.

In Fig. 7 I show a modification of Fig. 4, in which circular wiresare replaced by triangular wires, the washers being adapted to such change. The triangular wires may be rolled or drawn in the process of manufacturing, or

vprepared by other methods; andI make use IOO j or rodin .the cement.

load. By so doing I avoid the usual iron beam and liat arch construction; for the tile work of burnt clay or other material possesses the requisite strength for compression and my tension rods relieve it of the tensile strains which, without them, it would not be capable of withstanding.

In Fig. 2 is shown a construction of iiooring in which two layers of blocks are used with cement filling between them. My tension rods are shown embedded between adjacent blocks of the lower layer in masses of cement D. I nd it preferable, especially with narrow wall bearings, to place a washer upon the projecting end of the tension rod, and to turn over or head up on the Washer the ends of the Wires, as shown at cin Fig. 2. This washer gives a bearing surface upon the ends of the tiles and thereby relieves the cement about the end of the rod from excess ive shearing strains.

Besides giving greater and more tortuous exterior surface to tension rods, my invention, by furnishing abrupt shoulders to engage the cement, effectually anchors the cable I am therefore enabled to use a cement of weaker composition, and I find that lime mortar tempered with cement in the usual way possesses ample strength for forming the union between by tension rods and the hollow tiles, blocks of cement, or concrete, which may be used in the construction of fire proof floors, roofs, walls, area walks and the like. I do not find it any advantage, therefore, to substitute strands in my cable consisting of several small wires each, for the rougher surface thereby gained is of less advantage than is the stiffness obtained by strands of single wires of greater size. The latter will remain straight when laid in position without being stretched.

When my rods have been completed by the process of twisting, they are cut into proper lengths, and, when desired, a washer of large bearing surface is provided for each end of each rod to extend over the faces of the tiles and bear any excessive stress that may come upon the rod near the ends.

I have now set forth several embodiments of my invention as constructed for various uses. In a patent issued to me October 13,

1891, and numbered 461,028, I have shown the way in which artificial joists may be constructed from terra cotta tiles and tension rods, and in this present patent I have set forth a further development of the construction therein shown or described.

I do not claim .broadly a tension rod of twisted construction, forI am aware that such a device has heretofore been used. Neither do I in this patent claim a spiral or twisted rod consisting merely of two or more strands or wires twisted or laid together, as these form the subject matter of a patent No. 505,664, granted to me September 26, 1893, and entitled non-shearing rods for strengthening concrete work. In that patent also, I include a specific claim for the spiral ribs shown in Fig. 6, since such claim could not be made in the present patent.

What I do claim, and desire to secure by these Letters Patent, is the following:

1. A rod for the purposes described consisting of two or more strands twisted together but held apart at intervals by separating pieces for increasing the cement engaging and shearing surface of the said rod substantially as set forth.

2. A rod for use in concrete, mortar, cement, and the like, consisting of two or more strands of wire or small rods, and a separating piece or pieces placed between the strands of the said rod, the strands of the rod being held together between the said separating pieces, but allowed to separate around the said pieces, whereby greater cement engaging surface is produced, substantially as, and for the purposes, set forth. v

3. A tension rod for the purposes described consisting of two or more strands or wires, twisted together, and of separating pieces held in position by the said strands or wires and projecting from the said rod, whereby concrete or other embedding material may more firmly cling to the said rod substantially as set forth.

4. A twisted tension rod for the purposes described provided with pieces of metal or other material strung thereon, substantially as set forth.

5. A tension rod for the purposes described consisting of two or more strands, of angular cross section, secured together, substantially as set forth.

In testimony whereof Ihave hereunto set my hand this 11th day of April, 1892.

THOMAS A. LEE.

Witnesses:

CHAs. M. BEAM, 'HAROLD BINNEY.

IOO

Images