US1843454A - Mast arm support - Google Patents

Description

Feb. 2, 1932. R. H. MANSON MAST ARM SUPPORT Filed March 1, 193(1) ,W NMm Ww Patented Feb. 2, 1932 NITED STATES PATENT mm v I recast]- RALPH H. MANSON, or rnr-zrsnunen, PENNSYLVANIA, AssIeNon. ro HUBBARD & GOM;

PAN'Y, 0r" PITTSBURGH, PENNSYLVANIA, -A, coRronA'rIoN or r NNsYLvANrA MAST ARM Application filed March 1,

This invention relates to mast arm sup.-

" jeots.

An object of this invention is to provide a'mast arm support or pole plate that may be made by asimple stamping or pressing operation. f

Another object of the invention is to providea mast arm support formed from a single blank of: metal which when inplace will prevent both vertical and sidewise move-1 ments of the mast arm. F I

And astill further object of this invention is to provide a mast arm support that may be manufactured as a :single unitary structure, that shall be eflicient in operation, rigid and simple in construction and easily manufactured and installed.

Other objects of the invention will in part be obvious and will in part be apparent to those skilled in the art from the followingdescription taken in conjunction with the accompanying drawings, in which Figure l is a view in side elevation of a m'ast arm support or p ole'plate and 'a'mast' arm, only a i portion of which is shown,

mounted inplace thereon. V

Fig. 2 is a top plan view of thede'vice shown in Fig. 1 mounted in place on a pole or the like. r i V V Fig. 3 is a front view in elevation of the device shown in Figs. 1 and 2, the device in Fig. 8 diifering from the'device shown in Figs. land 2 in that a bushing is provided in place of a pulley for guiding conductors, not shown, to the-mast arm. 7 I

Fig. 4 is a partial view in section taken on line 4-4: of Fig.3; and Fig; 5 is a view in'transverse section of a casting and guide bushing embodied in the mast arm support, as illustrated in Fig. 3.

Throughout the specification j and the V from-the pole.

The inner en .surface of the Itached.

1930. Serial No. 432,547.

like parts.

p In the drawings, a mast arm support or pole plate -1 is shown that comprises a housing 2 ofinverted U-shape in transverse seci tion (see Fig. The housing 2, when the support is mounted in place on the pole 3 or other object, extends horizontally outward adjacent to the pole terminates in an upwardlyextending flange-land twooppositely disposed laterally extending flanges 5 and 6, the

flanges 5and 6 being located below the upwardly extending flange 4, as shown more" particularly in- Figs. 1 and 3. Theflanges 4i, 5 and filare'prefe'rably' shaped to conform to the contour ofthe pole'3, and in this case 1 since the pole 3 is substantially circular in transverse section, the flanges are arcuate" in shape. In caseithe mast arm 1 is to be supported or mounted on a wall or flat. object it is to be understood that the flanges 4,5 and 6 may be made flat so as to conform to the. wall to which they are at The flanges 4, 5 and 6 are providediwith apertures or openings through which lag screws may pass when driven or turned into the pole as shown in Fig. 2. I The opening or aperture in the flange 4:,IS disposed to accomv modate athroughbolt 8 ,that extends diadrawings like reference characters indicate a or the housing 2 which .lies

metrically throughthe pole from one side to:

the other in a manner well known in the art. The outer end of the housing 2 isprovided with bosses 9 and 10 that are substantially U-shapein section and which, form an arcuate bearing'face for a mast arm 11. The

bosses 9 and 10 are provided with. openings through which a downwardly bowed bolt 12 may pass for the purpose of drawing the clamp the mast arm 11 firmly in place. In order to limit the inward movement of the mast arm 11 intothe housing 2, the oppoouter end of the housing 2 together so as to w site sides of the housing are provided with tongues 12, which may be struck-out from the metal blank forming the housing and bent inwardly so as to provide stops to limit the inward movement of the mast arm.

Near the innermost end of the housing 2 and at points below the mast arm 11, openings or apertures 15 and 16 are provided to accommodate a stub shaft or pin upon which a pulley 17 located within the housing may be turnably mounted. The pulley l7, indi cated in broken lines in Fig. 1, is employed for guiding chains, ropes and the like (not shown) that lead tothe outeror free end of the mast arm. Thesechains, ropes and the like are employed for raising or lowering street lights suspended therefromntthe free or outer end of the mast arm.

If these operating chains, ropes and the like are arrangedto pass through the interior ofthe mast arm 11, the pulley'17 isimounted on a stub shaft journalled in the openings 15 formed in the sides ofthe housing. Where these operating chains, ropes andithe like are disposed to pass alongthe outside ofthe mast arm 11, the pulley 17 is moved downwardly andmounted on a stub shaft or pin journalled in the openings 16.

In applications where it is required that the electrical conductorsbe passed through 'theinterior of the mast arm 11 outto the free end thereof from which astreet light, (not shown) is suspended, a'hollo-w bushing 18 of refractory insulating material is provided through .Which the conductors pass and are guided into the .mast arm; This bushing has screw thread engagement with a casting or block 19 and is supported in place thereby.

As shown in 5 ,1the block or casting 19 isprovided with a lugor 'boss'20 which, when theblock is mounted in place, enten ds through an opening or aperture 21 in.a plate 22 (see Fig. 4 "The plate 22 is integrally joined by welding to the sides-of the housing at the point where it merges into the oppositely disposed flanges 5 andfi. Plate 22 1s preferably shaped to conform to the contour of ,the pole and forms a'bearing for the support 1 at the lowermost point of the housing 2, to take the compression component of the load imposed by a street light or similar object mounted on the free end of the mast arm 11. The outer end of the block 19 is provided with lugs 23 at opposite sides thereof through which a rivet 24 passes, the ivet being employed to secure the block or casting .19 in place as indicated more particularly in Figs. 3 -and 1 of the drawings.

From an inspection of Figs. 1, 2 and 3, it will be apparent that the oppositely disposed laterally extending flanges 5 and 6 are ei fective to prevent smewise movement of the mast arm 11 and that the vertically dis posed flange 4 prevents the mast arm from droopingdownwardlyat its free end. Flange 4% takes the tension component imposed by the bending moment of the load at the free end of the mast arm 11.

It will be observed also that the openings in the flanges i, 5 and 6 through which the through bolt 8 and the lag screws 7 pass, form, when joined by straight lines, an isosceles triangle. The mast arm support 1, therefore, provides a three-point suspension for the mast arm, the points of suspension .Ilying at the corners of an isosceles triangle.

This type of support, therefore, prevents sidewise movement of the mast arm as well as vertical movement. The mast arm will, therefore, be rigidly and positively held in place on the pole.

The mast arm support 1 illustrated in the drawings may be made from a blank of sheet steel or metal of the necessary thickness by a simple stamping operation and since this :the case the support admits of quantity production which is a vital factor in low cost to the consumer. The support 1 may be utilized in connection with wood poles as well as steel poles, although the pole '3i'llustrated in the drawings isof wood.

WVhile various modifications and changes maybe made in the mast-arm support herein shown and describedwithout departing from the spirit and scope of the invention, it is to be understood that only such limitations shall be placed on the invention as are imposed by the prior art and the appended claims. 7 7

What Iclaim as new and-desire to secure by Letters Patent is:

1. Aunitaryanast arm support comprising an inverted U-shaped housing having the arms at one end thereof flanged outwardly for forming a base shaped to conform to the contour of a pole and having outwardly ex: tending substantially U-shaped bosses provided with bowed inner surfaces on .the opposite end thereof for receiving a mast arm, a clamping member extending through openings in said bosses for securing said mast arm in said housing, a pulley in said housing at the inner end thereof, and means for mounting said pulley at different positions within said housing.

2. A unitary mast arm support comprising an inverted U-shaped housing, the in- .ner end of said housing having flanges eX- tending outwardly from the arms thereof and a flange extending vertically from the base thereof, said flanges forming a base plate for said support, means extending through openings in said flanges for securing said support to a pole or the like, said means being located at the corners of an isosceles triangle, the outer end of said housing having a plurality of substantially U- shaped bosses extending outwardly from the arms thereof, 'arcuate guides on the inner surface of said bosses for receiving a hollow mast arm, means extending through ap'ertures in said bosses for clamping the housing securely around said mast arm, a pulley, and:

positions subscribed my name this 27th day of February,1930. V I V RALPH I-I. MANSON.

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