US2143612A

US2143612A - Electric power transmission tower

Info

Publication number: US2143612A
Application number: US108663A
Authority: US
Inventors: Norman B Obbard
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-10-31
Filing date: 1936-10-31
Publication date: 1939-01-10
Anticipated expiration: 1956-01-10

Description

Jan. 10, 1939. B OBBARD 2,143,612

I ON TOWER Filed Oct. 51, 1936 [0 2/0 .Fgj, Z

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Patented J... 10, 1939 ELECTRIC POWER. TRANSMISSION TOWER Norman B. Obbard, Sewickley, Pa. Application October 31, 1936, Serial No. 108,663

2 Claims. (Cl. 189-22) UNITED STATES PATENT OFFICE This invention relates to towers for suspending wires and is particularly concerned with electric power transmission tower ground wire peaks, one of the objects being to provide a construction whereby the longitudinal wire pull is transmitted properly to the legs of the tower but adapted to accommodate the same.

Specific examples of the present invention are illustrated by the accompanying drawing, in which:

Figure 1 is a perspective of an electric power transmission line, the towers of which embody the features of the present invention.

Figures 2 and 3 are diagrammatic views representing two possible ways of constructing the ground wire peaks of a transmission tower to embody the features of the present invention, the tower as shown by Figure 1 having its peaks constructed according to the diagrammatic showing of Figure 3.

The drawing illustrates a tower having two of its legs I aligned parallel the ground wires 2 of the transmission line, the which therefore constitute a set of legs particularly well adapted to accommodate the longitudinal pull of these wires. Members 3 spread upwardly from this set of legs I and, in conjunction with other members, support a superstructure 4 designed to distributively transmit the vertical and transverse wire loads to all of the legs of the tower, it being understood that the other two legs of the tower also support this superstructure through the members 3.

This superstructure includes members 5 that are equally spaced on both sides of the towers center line and are aligned parallel with the longitudinal wire load. These members form continuations of the members 3 and are intended to transmit the longitudinal wire load to the legs I of the tower. However, conventional peak constructions are such that the longitudinal wire pull is transmitted to other parts of the superstructure so as to put the latter under a twisting stress. This is undesirable.

According to the present invention, the peak is in the form of a tripod extending from the superstructure 4 and having two of its legs 6 aligned parallel with the longitudinal wire load and connecting directly with the members 5 of the superstructure. The apex of this peak is arranged in the center line of the tower. The third leg I of the tripod extends transversely of the ground wire. and is connected with the superstructure 4 at the center line of the tower.

In the first example of the invention the superstructure 4 is in the form of a rectangular girder,

and this third leg I is connected to a member 8 arranged transversely of the superstructure.

In the second example of the invention the superstructure is in the form of a triangular girder having a member 9 arranged in the center line of the tower, and it is therefore only necessary to connect the leg I to this memberv 9. The apex II] of the peak is in each instance adapted to carry the ground wire 2 of the transmission line. 10

The transverse and vertical wire loads are transmitted by all of the legs of the tripod, that is to say, the legs 6 and I, to the superstructure 4 whereby the latter may distribute it to all of the legs of the tower and to the tower structure as a whole. However, due to the leg I of the peak being connected to the tower at the latters center line, the longitudinal wire load can be transmitted only through the members 5 of the superstructure and, by way of the members 3 to the legs I which are aligned parallel with the ground wires and are, therefore, best adapted to accommodate this load.

It is to be understood that a ground wire peak is different from a horizontal arm of triangular or other form. In the latter two legs may be aligned parallel with the longitudinal wire load but since the legs are in a plane at right angles, or nearly so, with any legs that may also be so aligned, the entire reaction is one of torque. To involve the problem solved by the present invention two of the peak legs must not only be alignedas mentioned but they must also be in a plane at least approximately parallel with the plane of the tower legs that are also so aligned. 3

I claim:

1. A wire suspension tower including legs for carrying all of the wire loads, a superstructure supported by said legs for distributively transmitting the vertical and transverse wire loads to the latter, said superstructure including members equally spaced on both sides of the towers center line in alignment parallel with the longitudinal wire load and connecting with a set of said legs aligned with the longitudinal wire load for transmitting the latter to said set of legs, and a tripod extending upwardly from said superstructure for supporting a wire from its apex, the latter being in the transverse center line of the tower and two of the legs of said tripod being aligned parallel with the longitudinal wire load and connecting with said members while the third leg extends transversely and connects with said superstructure in the transverse center line of the tower, whereby the longitudinal wire load is transmitted as through the first named legs of said tripod through said members and so primarily to said set of tower legs while the vertical and transverse wire loads are transmitted to the legs of said tower by distribution through said superstructure.

2. An electric power transmission tower including main legs of which two are aligned parallel with the transmission line, a superstructure supported by said legs, and a tripod extending upwardly from said superstructure with two of its legs aligned parallel with said line in a plane at least approximately parallel the plane of said two main legs and with its third leg connecting with said superstructure at the transverse center line of the tower, the peak of said tripod being adapted to support a wire extending parallel with the transmission line and said two main legs and said, two tripod legs interconnecting so as to transmit stresses at least approximately straight from the latter through the former to the ground. 10

NORMAN B. OBBARD.