US2582050A - Attaching parts to wooden poles - Google Patents

Description

Jan. 8, 1952 M. w. MANSON ATTACHING PARTS TO WOODEN POLES Filed Sept. 7, 1946 Patented Jan. 8, 1952 ATTACHING PARTS T oqn srotns Magnus William Manson, Johannesburg I I I t p I TransvaaLUnion ofSouth Africa a v 1 vi I Application September 7, 194c,jseria1 mists. 111' Union of South Africa September 1 Claim. (01. 287 54 This invention relates to means whereby parts such as cross arms for wire lines, pole stays and other fittings are attached to wooden poles.

Cross arms for telephone and telegraph lines are sometimes attached by means of a bolt passed through a hole bored in the wood and are stabilized by cutting a flat in the surface of the pole which forms a seating for the cross arm or other part rigidly connected to the crossarm. In either case cutting of'the wood mechanically weakens the pole and exposes the timber to deterioratinginfluences. Moreover if the pole warps by twisting, the cross arm is thrown out of perpendicularity with the line of wires, necessitating the pole being loosened in theground and rotated to compensate for the twist.

Cross arms are also attached to wooden poles by a halved clamp device, one half of the clamp being provided as a saddle welded to thearm and presenting a series of seating'edges, which in practice make little more than point contacts with the pole. The other half of the clamp is a straight barof channel section that presents the channel edges to the pole and accordinglyalso makes virtual point contacts with a pole. As a consequence of these contact formations the surface fibres of the pole are crushed; destroying the native resilience of the timber which is a factor in maintaining the tight grip of the clamp on the pole. Thereafter periodical weather changes cause alternate diametral expansions and. contractions of the good timber remaining within the crushed zone. These increase the radial extent of the initial damage and the rate of destruction in this manner is accelerated by the repeated retightenings of the clamp which are thus rendered necessary in order to maintain the arm rigidly at its initial position on the pole and to prevent its slipping down the pole.

It is an object of the present invention to overcome the drawbacks mentioned and to provide means by which cross arms can be attached to wooden poles with minimum destruction of the timber and in a manner which renders the attachment secure over long periods.

A device according to this invention comprises clamp elements which may be two or more in number and which collectively encircle and make internal contact with a considerable circumferential extent of the substantially cylindrical surface of the pole. The internal contact surface has a definite cylindrical character in that its extent parallel to the axis and \relatively to its diameter, is materially greater than that of the known clamps referred to above. Such longie I ,7, no; tudinal extent relatively to the diameter is such; as: toprovide'a; contact area large enough to make the clamping pressureper unit of area 'o'f'such low value as not to cause significant breaking of'thesurface wood fibres. I

"The internal contact s'urfaces'are'provided with pointed pins whicl'i'penetrate the surface of the pole to 'a substantial depth and thereby anchor th'e'a'ss'e'mbly' ofclamp elements againstits gravitational tendency to slipdown the pole. The

pins penetrate the-timber by spreading the fibres' apart rather than by "severing the individual fibres. With" the object I of causing the least' necessary disturbance to the fibre structure said-- pins are. directed parallel with the radial direction in which theparticular clamp element to which theyare attached, approaches the pole during the tightening movement of the clamp ele- The cl'ampfelements are themselves provided with tightening means and constitute the clamp. They are formed with laterally extending ears through which clamping bolts are passed} and a cross arm is secured to one of the elements, as

by weldingyand the clamping'bcilts pass through the ears provided on the-other,- or another; ne ment, and through holes in the cross arm.

Two forms of the invention are illustrated in the accompanying drawings, in which Figure I is a perspective View from beneath of an arrangement in which the cross arm is connected directly to one of the clamp elements;

Figure II is a fragmentary perspective View showing an alternative arrangement of the penetrating pin formations.

In the drawings, the pole is numbered 2, and the clamp elements 3, 3', the clamp shown consisting of two elements which collectively constitute the clamp assembly. Each of said elements 3 and 3' is provided with a pair of pins 4 welded to it, the said pins passing through the element and the pointed ends 5 penetrating the timber of the pole 2 when the assembly is tightened around the pole.

To enable the pins 4, 5 to penetrate the said timber by spreading the timber fibres apart, rather than by severing them, the said pins are, preferably, arranged parallel with one another and with the radial direction in which the clamp element 3 or 3 approaches the pole during .the tightening of the assembly around the pole.

Said clamp elements 3, 3' are formed with internal pole contacting surfaces 3a which are of definite cylindrical character in that the extent e of the surface in a direction parallel with r the assembly axis is, relatively to the diameter with a considerable enough to make the clamping pressure per unit v of area of such low value as;not-,t0.cause,sig-

nificant breaking of the surface fibres ofthe pole 2. l

The cross arm 6 is shown as welded-ton saddle I which'in turn is welded to the-element}, The other of the elements 3' is formed withradl-ally extending lugs 8; and cross bolts 9 pass through said lugs and through holes in the crossearm 6, the clamp assembly being tightened around th polezthymeans cfithe nuts 10. g g :Ifit be required tmrctate the cross arm .Sabout the 1001s. :in :the arrangement of ,Figure ,I it is necessary to :pry the elements out'of the =-pole .2

before said rotation can take place. Accordingly,

the 'arr..angement=of Figure :11 is provided-tore able rotation-to .be readilyeifected, I

In Figure II the ;pins --4 are shown as screw-f threaded and they are-screwed through thread ediholes providedin A the elements .3, .3 and :held in position against unintentional unscrewing .-.by lock-nuts?! 3. In attaching zthe clamp elements tothe pole,*,the pins I;are.initial1y' retracted, and

.A d vic for attachin parts :to wooden poles,-

ccmnrising clamp elements adapted collectively to encircle the pole .and make internal contact is holes in the 4 V circumferential extent of the substantially cylindrical surface of the pole. the internal contact surface of the clamp assembly having a definite cylindrical character in that its extent parallel to the axis of the clamp assembly and relatively to the diameter of the assembly is materially greater than that of the clamps at present in common use; pointed pins at the internal contacting surface adapted to penetrate the surface of the pole to a substantial depth; a cross arm rigidly attached to one element of the clamp assembly and having a hole at each side of the element, lateral ears on the opposite element of the assembly; and clamping bolts passed. through the ears and through the cross arm. MAG NUS WILLIAM MANSON.

REFERENCES CITED The following references are of record in the flle of this patent: i a

, UNITED STATES PATENTS Number Name Date 734,620 Sears July 28, 1903 743,964 Weir Nov. 10,1903

768,819 Palmer Aug. 30,1904 772,175 Palmer 0ct. 11, 1904 868,843 Clay -0ct. 22, 1907 878,867 Coldwell Feb. 11, 1908 964,140 Zahniser etal. July 12, 1910- .1,204,196 Schulz Nov. 7, 1916 1,485,629 Seeger Mar. 4,1924 1,575,614 Blaw Mar. 9, 1926 1,588,810 Rudolph et al June 15, 1926 1,843,454 Manson Feb. 2, 1932 1,967,288 Cathcart July 24, 1934 2,060,171 Burton Nov. 10, 1936- 2,118,467 Jones May 24, 1938 2,201,608 Causey May 21, 1940 FOREIGN PATENTS 7 Number Country Date 425,376 Germany Feb. 18, 1926 705,395 France June .5, 1931

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