US2570985A - Separable pole clamp - Google Patents

Description

Oct' 9, 195l E. w. RIEMENSCHNEIDER E-r/u. 2,570,985

SEPARABLE POLE CLAMP Filed June 28, 1948 l MM WM A TTORNE YS Patented Oct. 9, 1951 SEPARABLE POLE CLAMP Edmund W. Riemenschneider and Wilbur C. An-

derson, Canton, Ohio, assignors to The, Union A Metal Manufacturing Company, Canton, Ohio,

a corporation of Ohio Application June 28, 1948, Serial No. i-204 3 Claims. 1

The invention relates generally to clamps for supporting lateral arms or brackets on lighting poles and the like, and more particularly to a separable clamp which will wrap around the pole to adjust itself to various pole diameters within a limited range.

There` are certain prior separable or two-part pole clamps which are substantially rigid and which have out/turned cantilever ears for engage ing the clamping bolts, and when these clamps are. drawn together to clamp around various sizes of poles the forcel is transmitted from the bolts to the clamp at the bases ofthe ears. The result is that the *clamps tend to dig into the pole at` those points, and the ears will bend before sufcient wrapping contact of the clamp with the pole is accomplished,

Because of these point contacts between such. prior clamps and the pole,` the clamp is'apt to slip upor down or around the pole, and the clamp does not have maximum strength because the? clamping force is not transmitted substantially in awrapping direction, i. e. circumferentially of the pole, but is concentrated in particular points.

While certain prior clamps have had ears formed by bending the ends of the clamp into a. triangular shape., some of such ears have eX- tended too far around the periphery of the clamp with the result that unless curved clamping bolts are used, the bolts do not lie. closely enough to the. pole and the clamp. does not t a range of pole sizes because'of the large amount of Variation in the radial distance of the bolts from the pole.r In other prior clamps having these triangular ears, the ears have not extended far enough around the periphery of the clarnptol give full strength in a wrapping or circumferential direction when used with diierent pole sizes,I because the bolts have caused rthe ears to rock around their front ends as a fulcrum and thus pull the clamp away from the pole at the base of the ear.

It is a general object of the present invention to provide a` novel two-part clamp which overcomes all of the foregoing disadvantages of prior clamps.

Another and more specific object is to provide a novel two-part clamp which is adapted to wrap around and hug poles of dierent sizes within a substantial range, to give full surface contact between the clamp and pole.

.Another object' is to provide a novel two-part clamp in which the clamping boltsexerti their force circumferentially of the clamp to give maximum strength with minimum material.

A further object is to provide a novel two-part; clamp in which the @1amping;,earsare.ccinstructesl to. use straight bolts which lieelose to the pole throughout a substantial range of polev sizes.

A still further object is to provide a novel and improved vtwo-part clamp which is simple and inexpensive to make, and which is. easily applied without special tools.

These and other objects are. accomplished by the parts, constructions, arrangements, and combinations which comprise the present inventionl, the nature of which is set for-th lin the following general statement, and a preferred embodiment of which is set forth in the following description and illustrated in the accompanying drawings, and which is particularly and distinctly pointed out and set forth in the appended claims forming part hereof.

In general terms, the novel two-part clamp comprising the present invention preferably in-A cludes two clamping` bands of resilient material for wrapping around a range of sizes. of poles, thel peripheral length of each band being slightly less than one-half of the smallest pole circumferencev within the range, each band having itsI ends bent rearwardly outward and thenY inclined inward to form a. triangular ear, the shape ofthe` triangle being substantially equilateral, the front. side of theear being slotted to receive a straight clamping bolt at varying radial distances `from the pole, and the rear part of the ear being secured to the peripheral part of the band and havinga hole for receiving the clamping bolt.

Referring to the drawingforming part hereof in which a preferred embodiment of the invention is shown-by Way'of; examplel AFigure 1v is a plan view oi the improved clamp secured around a pole, the pole being Shown in section and the clamp in elevation;

Fig. 2 is a fragmentary plan sectional view through the clamp;

Fig. 3 is a frontA elevation of the clamp shown in Fis. 1;V

Fig; 4 is a side elevation thereof; and

Fig.A 5 is a fragmentary enlarged view similar to Fig. 1 showing two positions of the improved clamp secured on two. different sizes ofA poles.

Similar numerals refer to similar parts throughoutthe several views off the. drawing.

Theclamp shown in the drawing includes two parts orhands. 6 and 'l and the bands areof such Widthsas to-'requirevfgour clamping bolts 8 for drawing them togetheraround a y,circular pole 9. it will be understood that it isv within the scope of the invention to provide narrow clamping bands which require only two bolts for clamping them around, a P016;the'desisnand,construction or the clamping bands and their ears being otherwise the same as those shown and described herein.

For supporting a lateral arm on the improved clamp, the clamping band 'I is provided with a supporting boss indicated generally at I, which is adapted to be received in a complementary socket in the end of the arm for solidly supporting the arm on the clamp. Obviously, other ways of attaching lateral arms or brackets to the clamp can be employed without departing from the scope of the invention as defined in the claims.

Each of the bands and 'i has an arcuate peripheral body portion which is, preformed to conform substantially to the circumference of a pole having a diameter substantially equal to or slightly less than the largest diameter pole in the range of diameters for which the clamp is designed. Moreover, the inside peripheral length of each band is made slightly less than one-half the circumference of the smallest pole in said range, so that when the two bands are clamped around the smallest pole, their ends will not abut each other.

If, for example, the clamp is designed to t a range of poles of 4% diameter to 51/4 diameter, the inner radius of each of the bands 6 and I is made to be about 21% so that the curvature of the bands corresponds to the circumference of a pole 51/8 in diameter, and the peripheral length of each band is slightly less than one-half the circumference of a 41% diameter pole.

The material of the bands is a standard low carbon, low alloy, high strength steel plate of 1% thickness, which we have found in actual practice will wrap around poles of flg" diameter and upwards and give maximum strength to the clamp. The clamps may be made in several sizes to t ranges of pole diameters different from that given above, but in each case the curvature of the bands is preformed to conform to sub-- stantially the largest diameter pole within the range, and the inner peripheral length oi each band is slightly less than one-half of the outer circumference of the smallest diameter pole in the range.

The ears for engaging the clamping bolts 8 are preferably formed by inclining the end portion of each band outwardly and rearwardly to form a leg II and then bending the outer end inwardly to form a rear leg i2 inclined to the leg II, so that the legs II and I2 are at substantially equal angles to the intervening portion of the band 6a or la, and so that they form a substantially equilateral triangle with the band. The inner end of each leg I2 is secured to the band at I2', as by welding.

The outer'leg I I of each ear is provided with a closed slot I3 extending substantially radially throughout the length of the leg I I, and the slot I3 is adapted to receive a straight clamping bolt B at different positions radially of the ears for accommodating different sizes of poles 9, as in.v dicated in Fig. 5. The rear legs I2 of each ear are provided with bolt holes I4 aligned with the slots I3, and the holes I4 are preferably square for receiving the squared Shanks I5 of carriage bolts 8,. The width of each leg I2 from its end I2' to its connection with leg Il is ample to support the head i6 or nut 8 of a bolt.

In Figs. l through 4, the improved clamp is shown in position around a pole of a larger size diameter within its range, so that the clamping bands 6 and 'I are spread apart at the ears to a position similar to the dot-dash position shown in Fig. 5. When the same clamp is drawn to- 4 gether about a smaller diameter pole within its range, the ears assume the full line position shown in Fig. 5.

In Figs. 1 and 2, the clamping bolts are seated at the inner ends of the slots I3 and lie closely adjacent to the outer circumference of the pole 9. When the clamp is drawn together around a smaller pole by tightening the nuts 8', the ears are drawn closer together as shown in the full line position of Fig. 5, and the clamping bolts move slightly outwardly in the slots I3, but in each case the bolts lie quite close to the pole so that the force exerted by the bolts is transmitted to the clamping bands in a circumferential direction directly around the bands so as to cause them to wrap around and closely hug the pole.

If the ears of the clamping bands were formed so that the leg I2 was connected to the periphery of the band at a greater distance from the front end Il of the ear, the force transmitted from the bolts would be slightly more directly around the band, but the bolt head and nut would be moved inwardly of the pole circumference so as to require a curved bolt to accommodate a range of pole sizes.

By constructing the ears so that the legs I I and I2 and the band portions 6a or la form substantially an equilateral triangle, we have found that practically the full strength of the band is obtained for a substantial range of pole diameters while using straight bolts. We have found that for various ranges of pole diameters between about 41%" and 9%", a standard diameter carriage bolt will give the necessary tensile strength to insure wrapping the 1% bands around said poles.

The design and construction of the novel clamp provides for obtaining the full strength of the clamp in a circumferential direction around the pole within a range of pole sizes, Awithout causing the ears to bend or rock and dig into the pole, and without causing pulling away of the clamp at any point around the pole. We have tested the improved clamp in comparison with standard rigid clamps of substantially equal size and the same material but of slightly greater thickness, and find that the present clamp will resist a lateral pull of 15,000 pounds as against 4,500 pounds for the rigid clamp. an up and down pull of over 2,000 pounds as against 500 pounds for the rigid clamp and a torsional pull of 15,000 inch pounds as against 3,000 inch pounds for the rigid clamp.

The improved clamp is simple and inexpensive to make, and easily applied to or removed from a pole, without requiring special tools.

InY the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiment of the improved construction illustrated and described herein is by way of example, and the scope of the present invention is not limited to the exact details vof construction. l

Having now described the invention, the construction, the operation and use of a preferred embodiment thereof, and the advantageous new and useful results obtained thereby; the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

We claim:

1. A separable pole clamp for wrapping around a range of pole diameters including two arcuate clamp parts of semi-flexible material, each part having a peripheral length slightly less than one-half the circumference of the smallest pole diameter in said range, each part having each of its end portions inclined rearwardly outward and then inwardly in two legs forming substantially an equilateral triangle with the intervening peripheral portion of the clamp part, the front leg being slotted radially of the clamp for receiving a straight clamping bolt at different radial positions, and the rear leg having a closed bolt slot and its inner edge secured to the peripheral portion of the clamp part.

2. A separable pole clamp for wrapping around a range of pole diameters including two arcuate clamp parts of semi-flexible material, each part having a peripheral length slightly less than one-half the circumference of the smallest pole diameter in said range, each part having each of its end portions inclined rearwardly outward and then inwardly in two legs forming substantially an equilateral triangle with the intervening peripheral portion of the clamp part, the front leg having a closed slot extending substantially radial of the clamp for receiving a straight clamping bolt at diierent radial positions, and

the rear leg being secured to the clamp part and having a bolt hole aligned with said slot.

3. A separable pole clamp including two arcuate steel clamping bands of such thickness and resilience as to flexibly wrap under tension around a pole, each band having a peripheral length slightly less than one-half the circumference of the pole, each band having an ear at each end formed of two connected legs disposed at substantially equal angles to the band and forming a substantially equilateral triangle with the intervening portion thereof, the front leg being slotted radially and secured at its inner edge to the band and the rear leg being secured at its inner edge to the band and having an aligned bolt hole for receiving a straight clamping bolt at diierent radial positions.

EDMUND W. RIEMENSCHNEIDER. WILBUR C. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS HOSSfeld Oct. 11, 1932

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