US3182761A - Skeleton structure - Google Patents

Description

' May11, 1965 s. F. GQQDRUM 3,182,761

' f sK LETON STR March 8, 1962 2 Sheets-Sheet 1 May 1l, 1965 s. F. GooDRUM SKELETON STRUCTURE 2 Sheets-Sheet 2 Filed MarCh 8, 1962 INVENTOR.

SAMUEL F. GOODRUM United States Patent 3,182,761 SKELETON STRUCTURE Samuel F. Goodrum, Sharpsville, Pa. (918 Park Ave., Syracuse, N.Y.)

Filed Mar. 8, 1962, Sel'. No. 178,379 2 Claims. (Cl. 1S9--15) This invention relates to the art of constructing skeleton towers of metallic sections and is more particularly concerned with the problems encountered in the assembling and erection of such structures in the fieldfor example, inthe building of electrical power transmission lines. now is to deliver the structures rto the erection sites `in knocked-down condition and' to haveerection `crews assemble :the structures piece-by-piece in upright position, after which the hardware required in the specialized end use of the structure is affixed. Sincevpractically all this work is done high above the ground the work proceeds slowly due to the meticulous care required and thus is very costly.

In attempts to facilitate andvto reduce the cost of erection of skeleton towers it has been heretofore proposed to assemble the tower structures in horizontal position on the ground, and after afxing the necessary hard- In such operations, the common practice 3,182,761 Pancentted May 1l, 1965 lCC , infinite length along the tower line to reachareas where ware, to tilt the structures up into vertical position wheret r by their supporting legs may be connected to anchoring supports which are normally part of pre-prepared supporting piers. These attempts have not been successful,

however, due to the impracticality of transporting the complex erection equipment heretofore required to the 7 tower `sitesfor example, along a power transmission lineand also due to the fact that the towers were often bent and otherwise damaged during the erection process.

It isaccordingly the primary object of this invention to provide an improved arrangement whereby skeleton towers can be assembled in horizontal position on the ground and thenupended to standing positions on their axis of the assembled tower over which an erecting cable may be strung to thereby provide a moment arm of substantial dimension to facilitate the up-ending of the tower. This A-frame or compression boom abuts against one general side face of the `tower structure and to resist the thrust the tower structure is reinforced with an integral truss at this point. Excessive deflection and bending of the tower structure during the erection process is thereby eliminated.

A further and more specic object 'of the invention is the incorporation of the above mentioned erecting frame or boom as an integral part of the tower structure so that each assembled tower may be self-contained and only winch means is required to be moved from tower to tower to erect the same. These Winches may be conveniently carried on crawler type of tractors as is well understood and thus are readily available for use in wild rough country not suitable for trucks, trailers, etc. normally used to transport rigging. Further, aswill be more apparent below, rny method of tower construction and erection permits construction in areas even inaccessible lto crawler tractors-so long as materials `for the towers and assemblying personnel can somehow be delivered tothe sites-by helicopter, for example. This is made possible because the only erection rigging required is a pair of oppositely extending cables which may be of power-operated Winches may be located.

, The above and other object-s rand advantages of the invention will become `apparent upon consideration of the following specification and the accompanying drawing wherein there is disclo-sed certain preferred embodiments of the invention.

In the drawing: r

FIGURE l is a perspective view of a skeleton tower constructed Vand erected in accordance with the principles of my invention;

FIGURE 2 is the tower of FIGURE l in horizontal position ready for erection; v

FIGURE 3 is a modified lform of tower in the position of lbeing erected in accordance with the principles of my invention;

FIGURE 4 is a schematic showing of a modified form of top construction which may be employed in `the towers of my invention; and

FIGURES 5 and 6 are fragmentary front and side elevations of the erecting A-frame utilized in the assemblies of FIGURES l and 2.

Whilein actual practice the skeleton towers to which mysinvention may be applied may assume widely varying structural arrangements and details, I have chosen `for illustration purpos-es `a rather heavy tall -tower commonly used to support current conductors in electric tower transmission lines. Such towers are commonly square in plan having an upwardly tapering principal portion 11 and an upwardly extending top portion 12` from which extend the braced lateral arms 13 supporting at their outer ends insulators 14 used to carry the power transmission wires. `These towers are assembled from discrete lengths of lightweight structural steel members or sections, and itis common practice to make the corner members 15 of angles which extend downwardly 4to suitable 4anchors used to support Iand retain the tower on concrete piers, platforms and the like. Such piers are shown at 16 in the drawing, the anchors at 17, and the latter are arranged to have pin connection with the lower ends of the structural members making up the four corners of the tower. As shown in the drawing, the tower structure includes, in addition Vto the elongated corner members, a multiplicity of horizontally disposed spacing members 18 and Various diagonally disposed brace members 19 lying in the planes of the four sides of the structure. The "assembly is so designed that when placed in rigidly anchored vertical Iposition it is sufciently strong and rigid to support the considerable weigh-t of lthe transmission wires and to withstand any wind loads which may Areact against the wires and tower `structure. However, for these resultant loads the strength requirement against bending of the tower out of its vertical alignment or axis, particularly when the corner angles are rigidly anchored at their ybottom ends, is rather reasonable and consequently the spacing and bracing members may be rather light in cross section. Heretofore, this characteristic has made it extremely difficult to erect the towers by up-ending structures which have been fully assembled in horizontal position on the ground. The beam strength or resistance to deection in directions normal to the principal or vertical axis of the tower is rather limited and while `attempts have heretofore been madeV to erect towers in this seemingly economical many ner the complexity of the rigging required and the fre- 'quency of damage to .the tower structures has made the i dicated by reference numeral 15r) of adequate strength V and design to serve as tension members for bottom chords in the trusses for the purpose to be hereinafter described. Sections 15r may, ,of course, be provided by simply reinlforcing the general continuing members 15 or bymaking the sections of greater thickness and cross-sectional tensions as will be understood. In either case, the sections 15r are rigidly connected to the continuing corner sections 1S. To complete the trusses I provide the spacing members l8r and the diagonal braces 19 and, again, these members l8r and 191A are preferably of heavier effective section and of greater strength than the other components of the tower structure. U-pon the assemblies comprised of the parts 151', l8r and l9r bein-g employed as trusses the parts l8r and 19r serve as compression members. rl'lhe apices of these trusses are rigidly interconnected by a strut 20, and in the embodiment of the invention shown in FIGURES 1 and 2 lugs 21 are'secured to the outer face of this strut. These lugs are vfor the purpose of pivotally mounting the base ott an erecting A-frame 2.2. While this frame may be constructed in various ways, it may consist simply of a pair of heavy angle members connected at their top end portions by a heavy ilanged steel plate 23 which is welded thereto. See FIGURES and 6.

In assembling and erecting the tower described above, the pre-cut component parts are delivered to the site normally in bundles by any suitable means and, of course, the piers 16` and anchors 17 will have been constructed by this time. First, the trusses comprised of the parts r, l8r and 191' are preferably assembled and are pivotally connected to two of the anchors 17 as shown in FIGURES 2 and, 3. With the aid ci suitable blocking, the remainder of the tower is then assembled onto these trusses in reclining or horizontal position and since most of the work is performed directly on the ground this assembling proceeds very rapidly-including the hanging of the insulators 14 and the placing of pulleys, not shown, which are temporarily secured to the tower arms to temporarily support the transmission wires during erection of the complete line. Upon this hardware being attached to the assembled tower the A-frame 22` (in the embodiment of FIGURES 1 and 2) is now connected to the lugs 21 and a pair of cables 24 and 2S are connected to spaced points along the upper reaches of the tower.V The other ends of these cables are connected to hooks 26` which engage apertures formed in the ilanges of the plate 23, and the cables are so adjusted as to length that both remaintaut when the frame 22 is pivoted upwardly to a position substantially normal to the longitudinal or principal axis of the tower. As shown in FIGURE 6, a cable sheave 27 is pivoted `onto the plate 23 and entrains a cable 28 one end of which may lead to a deadman, not shown, while the other reach is extended to a power-operated winch, also not shown, which may be of the kind commonly mounted. on the front or back end of a crawler-type of tractor.

It will be apparent that as a pulling torce is applied to the cable 28 the A-frame 22 will rock up and the pulling torce will be transmitted to the cables 24 and 25. Thereafter, the entire tower structure will rock up about the pivotal point ot one end of the sections 15r. The vertical distance between these sections and the top of the A-frame 22 will provide a substantial moment arm forthe upturning ot the tower structure. Of course, the cables will exert a large force downwardly through the trame 22 but this will be effectively resisted by the action of the trusses comprised of the parts 15r, l8r and 19r without bending ot the tower along its longitudinal axis. Further, i

since the trame 212 may be of substantial height the cable 25 is steeply angled to the principal axis ot the tower and therefore a substantial upward component of torce may be excited through this cable. Since itis attached to the upper end portion of the tower the unsupported cantilevered weight is kept to aminimum and the tower upends without bending or excessive deflection.

Vuse.

In the embodiment of the invention shown in FIGURE 3 the tower structure is substantially identical to that of FIGURES 1 and 2 except that the lower portions (15b) of the corner angles 15 which are on the opposite face of the tower from the truss chords 151' are pivoted at ISC to the apices of the trusses and are interconnected at the-ir lower ends by a rigid strut 15d. Thus, as illustrated in FIGURE 3, these lower portions of the corner sections (which also form two legs of the tower structure) can be utilized in the erection process for the same purpose as the trame 22 in FIGURES 1 and 2.- In this embodiment, however, the erecting cables Zlib and 25h have only a bearing relation on Vthe strut 15d so that after the tower is upended to a predetermined angle these cables move free of the strut 15d and, thereaxter act directly on the upper reaches of the tower structurepermitting the assembly of the parts 15b, 15d to be lowered by a cable 3i). While the tower structure is temporarily held in vertical positon by the erecting cables 24b, 25h and the snubbing cables 219 the lowel ends of the legs 15b may be pinned or otherwise rigidly secured to their anchoring means.

A singular advantage of the tower constructions and method of erection described above is that lthe tower structures may be readily assembled at their erection sites lfrom component parts which are easily handled and readily transported to the sites with practically all the work being done on the ground and that thereafter the towers may erected by means of simple and readily transportable 'Winches and cables. It is not necessary that the Winches be brought closely to the erection sites since the snubbing cables 29 and the erecting cables (28 in FIGURE 2 and 24h, 25b in FIGURE 3) may be of inlinite length. In either embodiment excessive strains on the structural members of the towers do notfjoccur during the erection process because of the l-arge upturning moments provided by the compression members (.22 in FIGURE 2 and 15b in FIGURE 3) and because Kof the litting force exerted on the upper reaches of the tower. All this is made by the truss structure or structures built into the lower reaches of the towers.

When constructing and erecting exceptionally high towers in the manner described above I propose to make the tower telescopic as shown schematically in FIGURE 4 wherein the upper portion of the tower 12b may telescope into the tapered portion IIb of the tower. For this purpose, lthe insulator and wire supporting arms lb would be pivoted to the tower section 12b as at 3l and the braces therefor shown at 32 would be readily disconnectable whereby the arms 13b could beV swung upwardly to be received within the structure 11b when the tower section 12b is slipped into it. Upon erection, the tower yof FIGURE 4 would be telescoped tothereby very greatly reduce the upending forces required. Upon the structure being upended to vertical position and anchored, the section 12b is elevated by a block and tackle or other suitable means, the arms 13b swung outwardly; the braces 32 being applied as the raising proceeds. After the section 12b reaches its linal position its lower end is securely bolted to the upper end of the tower section 11b.

It should now be apparent that I have provided improved skeleton tower constructions and methods of erecting the same in the eld which accomplishes the objects initially set out. Since the principles of the invention may be used in many different specific embodiments without departing from the spirit or scope thereof reference should be had to the appended claims in determining the scope of the invention.

I claim:

1. A skeleton tower structure formed of interconnected elongated structural members and designed to be assembled in horizontal position on the ground and thereafter tilted upwardly to permanent vertical position, certain of said structural members forming corner posts of said tower structure and other of said structural members forming diagonal braces between said corner posts, the lower-most end portions of two of said corner posts lying in a common plane, the lower-most ends of said two of said corner posts being adapted to be pivotally connected to a supporting foundation, trusses built up on said portions and extending normal thereto and each comprised of a compression member extending from the apex thereof normal to an intermediate point on said portion as well as other compression members extending from the apex to the ends of said portion, said trusses extending the full width of the tower structure from said portions, and an elongated compression member connected at one end to the apices of said trusses and extending outwardly of said apices generally normal to said portions, the arrangement being such that when said tower structure is lying horizontally on the ground said trusses together with said last mentioned elongated compression member forms a moment arm to upend the tower structure by pivoting on said supporting foundation upon pulling horizontally on a cable which is connected to a top portion of the tower structure and entrained over the outer free end Kof said last-mentioned compression member.

2. Structure according to claim 1 fur-ther characterized in that said last-mentioned compression member is pivotally connected to the tower structure at the apices of the trusses and is so constructed that after said structure is upended to substantially vertical position, said member may be swung downwardly to form a supporting leg portion of the permanent tower structure.

References Cited by the Examiner UNITED STATES PATENTS 1,949,750 3/34 Lunt et al. 189-15 2,530,848 11/50 Woolslayer et al 189--15 FOREIGN PATENTS 900,775 7/45 France.

RICHARD W. COOKE, JR., Primary Examiner'.

y JACOB L. NACKENOFF, Examiner.

Claims (1)

1. A SKELETON TOWER STRUCTURE FORMED OF INTERCONNECTED ELONGATED STRUCTURAL MEMBERS AND DESIGNED TO BE ASSEMBLED IN HORIZONTAL POSITION ON THE GROUND AND THEREAFTER TILTED UPWARDLY TO PERMANENT VERTICAL POSITION, CERTAIN OF SAID STRUCTURAL MEMBERS FORMING CORNER POSTS OF SAID TOWER STRUCTURE AND OTHER OF SAID STRUCTURAL MEMBERS FORMING DIAGONAL BRACES BETWEEN SAID CORNER POSTS, THE LOWER-MOST END PORTIONS OF TWO OF SAID CORNER PORTS LYING IN A COMMON PLANE, THE LOWER-MOST ENDS OF SAID TWO OF SAID CORNER POSTS BEING ADAPTED TO BE PIVOTALLY CONNECTED TO A SUPPORTING FOUNDATION, TRUSSES BUILT UP ON SAID PORTIONS AND EXTENDING NORMAL THERETO AND EACH COMPRISED OF A COMPRESSION MEMBER EXTENDING FROM THE APEX THEREOF NORMAL TO AN INTERMEDIATE POINT ON SAID PORTION AS WELL AS OTHER COMPRESSION MEMBERS EXTENDING FROM THE APEX TO THE ENDS OF SAID PORTION, SAID TRUSSES EXTENDING THE FULL WIDTH OF THE TOWER PORTION, SAID TURSSES PORTIONS, AND AN ELONGATED COMPRESSION MEMBER CONNECTED AT ONE END TO THE APICES OF SAID TRUSSES AND EXTENDING OUTWARDLY OF SAID APICES GENERALLY NORMAL TO SAID PORTIONS, THE ARRANGEMENT BEING SUCH THAT WHEN SAID TOWER STURCTURE IS LYING HORIZONTALLY ON THE GROUND SAID TRUSSES TOGETHER WITH SAID LAST MENTIONED ELONGATED COMPRESSION MEMBER FORMS A MOMENT ARM TO UPEND THE TOWER STRUCTURE BY PIVOTING ON SAID SUPPORTING FOUNDATION UPON PULLING HORIZONTALLY ON A CABLE WHICH IS CONNECTED TO A TOP PORTION OF THE TOWER STRUCTURE AND ENTRAINED OVER THE OUTER FREE END OF SAID LAST-MENTIONED COMPRESSION MEMBER.

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