US1687449A - Tower construction - Google Patents

Description

H. O. HILL TOWER CONSTRUCTION Oct. 9, 1928. 1,687,449

Filed July 28, 1926 Patented Oct. 9, 1928.

UNITED-STA TES PATEN T OFFICE.

MANUFACTURING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TOWER CONSTRUCTION.

Application filed July 28,

This invention relates to improvements in steel transmission towers employed for supporting electric conducting wires or cables,

and it relates more particularly to that class of towers having cross arms from which suspended insulators strings for supporting the conductors are hung.

In use, electric conductors or circuits supported on steel transmisison towers and poles are quite often subjected to interruptions in the continuity of the current due to arcs or flash-overs from the conductors to the adjacent steel members of the structure, due to lightning disturbances. These flash-overs usually disrupt the service and render all users of the power without service until the damage to the circuits can be repaired and the service restored,

Attempts have been made to eliminate or reduce arcing or flash-overs by spacing the conductors, wires, or Cables away from the cross-arm hanger braces and other tower members, so that the air gaps between the conductors and the braces or other members will afiordsuificient resistance toprevent arcing. This necessitates the use of long crossarms and very high structures and long strings of insulators, all of which materially increase the cost of the transmission line and thus the cost of the electric service.

The crossarms, hangers, and other parts entering into tower construction, adjacent to or relatively near the conductors, have usually been formed of steel bars placed on edge or steel angle members having sharp edges or corners. This construction, embodying members of the character stated and positioned as described, provides one that'is pal?- ticularly liable to produce arcing or flashovers. I have discovered that by forming the exposed surfaces of the said members nearthe conductors without edges, sharp angles or corners, arcing or flash-overs at these points are practically eliminated.

Among the objects of my invent-ion are, to provide a tower construction embodying members, disposed close to the conductors, having curved or rounded exposed surfaces, and a construction devoid of sharp edges, angles, and sharp corners; also, to provide a construction that eliminates or greatly reduces the liability of arcing from the conduc= tors to certain tower members, without the nemas =iid5 of large vertical and horiziintal 1926. Serial No. 125,420.

separation of the conductors and said members.

In the accompanying drawings, whichillustrate applications of my invention:

Fig. 1 is an elevational view of a portion of a transmission tower embodying my invention Fig. 2, a horizontal sectional view taken on line IIII of Fig. 1; r

i Fig. 3, a view similar to Fig. 2, taken on line IIIIII of Fig. 1;

Fig. 4, a detail plan view of a cross-arm constructed of tubular members;

Fig. 5, a detail plan view, partly broken away, of a tubular structural member that may be employed in the tower construction;

Fig. 6, a similar View of amodified form of member;

Fig. 7, a detail elevational view, partly broken away, of a structural steel member and its tubular protective covering;

Fig. 8, a view similar to Fig. 7, showing an irngle member and its protective covering; anc t Fig. 9, a sectional view, the section being taken on line IX-IX of Fig. 8.

Referring to the drawings, the tower structure, as illustrated, includes the usual vertically extending corner diagonals t3 extending across the four sides of the tower and Connected with the corner posts in the usual manner.

Extending upwardly from the upper ends of the corner posts 5 are four vertically extending angle members 7, said members constituting the corner posts of the upper square portion of the tower. 8 designates crossmembers or diagonals also entering into the construction of the said upper tower portion.

Disposed at the desired levels on the upper tower portion are a plurality of cross arms 9, 10 and 11. These cross-arms are secured to the top portion of the tower, designated generally by the character A, and project from two faces or sides thereof in the usual manner.

Suspended from the outer ends of the respective crossarms are string insulators 12. Each of the said string insulators is designed to connect with an electrical conductor, wire or cable 13.

The respective cross-arms 9 and 10 are preferably braced by hanger members or han er braces 14 and 14 having their inner ends connected with. the comet members '7 and posts 5 and the cross extending downwardly and outwardly therefrom. The upper cross-arm 11 is reinforced by hanger braces 15 extending downwardly from the top tower members 16.

Located immediately under the upper cross-arn'i 11 and on two faces of the upper portion A of the tower and between the said cross-arm and the liangenbraces 146, I provide protective plate member 17. These plate members are secured to the members 7 and preferably have rounded ends or edges 17 The function of the said protective plates is to prevent arcing or flash-overs from the conductors to that portion of the tower covered by said plates. 18 designate similar protective plate members disposed on two sides of the tower structure just below the lower cross-arm 9 and relatively close to the lower insulator strings 12 and the lower conductors 13.

In order to prevent arcing between the conductor lines and the angle members entering into the formation of the respective crossarms, said members are provided with protective members 19 having rounded exposed surfaces. These protective members 19 are particularly shown by Figs. 8 and 9,- Fig. 9 shows rivets 19 for securing the member 19 to the angle member of the cross-arm. It is, or course, evident that, so long as the protective member 19 has a curved surface, the cross-section thereof may vary. For we ample, it may be either circular, as in the form of Fig. 7, or semi-circular, as shown by Fig. 9; or the protective covering may be spherical. The said members may be made of sheet material or of wire mesh.

The hanger braces 14 are usually bars and, if this is the case, I preferably employ a circular protecting covering member 20. Such a member will afford protection to the said hanger members from the conductors carried by the upper cross arm 11 and the intermediate cross-arm 10.

Fig. 4 shows a cross-arm formed of tubular members 21, said members 21 being shown also in the enlarged view, Fig. 5. A crossarm could also be constructed of members 22 shown by Fig. 6. anger braces might also take the form of members 21 or 22.

My invention contemplates the employment of curved surfaces, either in the form of coverings for angular members or bars, from which the tower cross-arms and other tower members relatively close thereto are formed, or the employment of such surfaces in the formation of the said arms per se and the members relatively close thereto. It further contemplates the use of protective plate members, as shown and described.

lVhat I claim is:

1. In a structural tower, the combination with a suspended insulator string carrying a transmission wire, of an upper body portion formed of angular members, a cross-arm formed of angular members, a metallic protector plate on the body adjacent the crossarm, and metallic protector elements for the cross-arm members having curved surfaces.

2. In a structural tower, the combination with a suspended insulator string carrying a transmission wire, of an upper body portion formed of angular members, an upper, a lower and an intermediate crossarm formed of angular members, a metallic protector plate on the body adjacent the upper crossarm, a similar plate adjacent the lower crossarm, and metallic protector elements having curved surfaces for the cross-arm members.

3. In a structural tower, the combination with a suspended insulator string carrying a tral'ismission wire, of a plurality of cross arms arranged one above the other, a protective metallic plate covering for the body of: the tower located between two adjacent cross arms, and metallic protector elements having curved surfaces for the cross-arm members.

In testimony whereof I affix my signature.

HAROLD O. HILL.

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