US 2835002 A
Description (OCR text may contain errors)
May 20, 1958 J. v. MAJEWSKI' 2,835,002
CONNECTOR AND JOINT FOR SPAR TYPE TIMBER CONSTRUCTION Filed Aug. 26, 1954 JOHN v. MAJEWSKI a INVENT OR. BY M M u l ATTORNEY United States CONNECTOR AND JOINT FOR SPAR TYPE TIMBER CONSTRUCTION John V. Majewski, Milwaukee, Wis., assignor to McGraw- Edison Company, a corporation ofDelaware The present invention relates to timber connectors, and more particularly to connectors for joining a transversely disposed spar arm to a pole support.
In the field of high voltage transmission there has been a tendency to replace steel towers with wood structures for supporting the conducting lines. Wood structures raise the insulation level of the lines, therebyv reducing the occurrence of phase to phase, and phase to ground flashovers caused by lightning and switching surges. In addition, wood constructions, such as the so-called H-frame structure reduces the cost of transmission line construction, The H-frame structure comprises two wood poles supporting a transversely disposed cross arm from which the transmission line conductors are suspended. Both the pole and cross arms are of unsqua-red timber from which the bark has been removed, but is otherwise in its natural state.
It has, in the past, been common practice to bolt the various cross arms and supporting braces to the wood poles, which required drilling of holes for the bolts and cutting away certain portions of the pole and cross arms to provide gains for seating the pole and cross arm relative to one another. In the case of spar arm construction, such gains were often cut as circular grooves. in any case, the drilling of holes and cutting of gains and grooves materially reduced the bending strength of the wood members. The insertion of bolts often crushed adjacent wood fibers and even caused the wooden members to split. Bolt holes and grooves provide an easy access to rain and snow and intimate contact therebean atmosphere conducive to decay.
Although it is preferred to provide a structure having no bolt holes for the reasons outlined above, it is a continued practice in some instances to use thru-bolts. Nevertheless, when such structures are provided, it is desirable to provide a means of permitting drainage and quick drying of the wood members.
It is an object of the present invention to provide a wood connector for use in spar arm construction which may be used in conjunction with supporting bands or half bands, and if desired, in conjunction with thrubolts.
It is another object of this invention to provide a.
wood connector for spar arm construction which connector is designed to embrace a portion of the pole and of the spar by means of a plurality of spurs in order to take advantage of seating the transversely disposed members relative to one another without destroying any of the bending strength of these wooden members as transmitted through their tough outer fibres.
It is a further object of the present invention to provide a wood connector of a flexible stamped member designed to accommodate a wide range of pole and spar diameters.
It is still another object of the present invention to provide a one-piece wood connector for use in spar arm construction, which connector, if used in conjunction with atent tween encourages moisture to remain and also provides thru-bolts will permit a minimum contact between the wood members and a construction permitting adequate drainage and drying of any atmospheric moisture.
For a better understanding of the present invention, reference may be had to the accompanying drawings, in which:
Fig. 1 is a perspective view of the novel wood connector.
Fig. 2 is a top plan view, shown in phantom, of a pole and spar arm construction having the wood connector interposed therebetween.
Fig. 3 is a side elevational view, shown in phantom of the construction illustrated in Fig. 2.
Referring now to the drawing and particularly to Fig. 1 thereof, there is illustrated an embodiment of the present invention taking the form of a metallic stamping to provide a wood connector 1 having an arcuately formed base 2 and formed at opposed sidesthereof to provide outwardly extending spaced-apart arms 3 and 4. Each of the arms 3 and 4 is further formed to provide oppositely extending flanges 5 and 6. Each of the flanges 5 and 6 are preferably formed with an arcuate contour and are provided with inwardly projecting spurs 7.
The base portion 2 of the connector may be provided with a centrally located aperture 10 arranged to receive a thru bolt (not shown), if such is desired. Additional spurs 11 are punched through the base portion as shown, and project in a direction opposed to the direction of spurs 7.
Referring now to Figs. 2 and 3, the preferred pole and spar construction are as shown with the use of half bands 15 and double-arming bolts 16. The half bands are formed at their ends to provide opposed apertured mounting ears 17 for receiving the bolts. The mounting ears are preferably provided by bending the strap metal forming the band back upon itself in the manner illustrated. The double-arming bolts threaded at both ends to receive the nuts 18. It will be apparent, that thrubolts having a single threaded end and upset to provide a head (not shown) at the opposite end may be used. Or if so desired, conventional U-bolts may be substituted for one set of the half bands (not shown), which U-bolts are adapted to receive either the pole or the arm in the bail thereof.
In operation, it is the usual practice, especially in the case of new construction, to fasten the various pieces together while the members are lying on the ground. After initially securing the members, the frame is raised to standing position with the lower ends of the poles 19 being positioned in previously-dug holes in the ground. While on the ground, the connector is placed over the pole with either the base 2 or the arcuate flanges 5 and 6 adjacent the pole, as desired. The spar arm 20 is then seated as shown, transversely of the pole, lying in the other arcuate portion provided by the flanges or base, respectively. The half-bands are positioned around the pole and arm, and the bolts 18 are threaded through the apertured ears 17 of corresponding half-bands. The nuts are then threaded on the ends of the double-arming bolts and are tightened as desired. After the frame has been assembled and brought to standing position, minor adjustments of the bands and bolts may be made.
As suggested above, the connector may be positioned in either direction relative to the pole and cross arm. This may be governed by the pole or arm circumference or manufacturing variations of the arcuate base or flange. However, it will be apparent that the arrangement illustrated in Figs. 2 and 3 is preferred. It will be noted from Fig. 2 that there are relatively unobstructed vertical passages between the base and the pole when the base is positioned adjacent to the pole, as shown. These pasassaoaz sages provide excellent drainage facilities for atmospheric moisture that would otherwise tend to accumulate.
It is to be noted that the gain is flexible in its embracing surfaces so that it may accommodate a variety of pole and spar diameters by simple adjustment of the tightening bolts. By being of a one-piece construction, the connector has the advantage over a two-piece member as there is no shear stress imposed between two mating portions.
Although the connector embodiment illustrated and described hereinabove is a preferred structure, it is within the province of the present invention to provide a connector of cast construction (not shown). That is, a connector may be cast with integral opposed spurs and angularly disposed contoured portions facing oppositely of one another similarly to the stamping shown and described. It will be apparent, however, that a cast structure will not have the flexibility nor the access for drainage of collected moisture as does the stamped member.
I claim as my invention:
A joint between two angularly disposed members each having an arcuately contoured periphery at said joint, comprising in combination, a connector disposed between said members consisting of a stamping integrally formed of a rectangular blank of sheet metal including a base member having a concave surface engaging one of said angularly disposed members substantially coextensive the entire extent of said concave surface, a through bolt hole formed in the center of said base portion, said blank being upturned at opposed sides to provide substantially parallel flange portions extending outwardly of the base member in a direction away from and substantially normal to a chord subtended by the arc of said concave surface and intersecting said flange portions, each of said flange portions being further formed at their respective extremities to provide a flanged arcuate concave surface and engaging the other of said angularly disposed members substantially coextensive the entire extent of said concave surface, said flanged surfaces lying in a plane spaced from and angularly disposed relative to the plane of the concave surface of said base member, oppositely facing spur teeth formed from said blank of sheet metal and projecting from each arcuate surface and engaging the respective angularly disposed members, said spur teeth formed in said base portion being in two parallel rows disposed at right angle to said flange portions, said spur teeth formed in said flange portions being formed intermediate the end surfaces thereof, and two pair of half-bands, each pair being in spaced apart embracing engagement with a respective angularly disposed member, and double-arming bolt and nut assemblies releasably joining the respective half-bands and drawing the said angularly disposed members towards one another to complete the said joint between the members.
References Cited in the file of this patent UNITED STATES PATENTS 868,843 Clay Oct. 22, 1907 900,663 Callane Oct. 6, 1908 1,043,260 Shover Nov. 5, 1912 2,606,952 Cofer et a1 Aug. 12, 1952 2,704,586 Kennedy Mar. 22, 1955 FOREIGN PATENTS 26,980 Great Britain Dec. 2, 1911 356,799 Great Britain Sept. 14, 1931