US2822067A - Antenna mast - Google Patents

Description

Feb. 4, 1958 K. B. PRICE 2,822,067

ANTENNA MAST Filed July 5, 1952 2 Sheets-Sheet l $0 IVENTOR.

Feb 4, 1958 K. B. PRICE 2,822,067

ANTENNA MAST Filed July 5, 1952 I 2 Sheets-Sheet 2 INVENTOR;

United States Patent M ANTENNA MAST Kenneth B. Price, Pontiac, Ill.

Application July 5, 1952, Serial No. 297,281

3 Claims. (Cl. 189-26).

This invention is concerned generally with an antenna mast and more particularly with a mast designedfor permanent installation and adapted to be readily portable before permanent installation and with structure for transporting and installing the mast.

High frequency radio waves such as are used in television transmitting are subject to many limiting phenomena. Such waves generally are limited to line of sight transmission, but to some extent tend to follow the earths curvature when propagated at suflficiently high power levels. The waves are readily reflected, deflected or absorbed by various natural and man-made barriers such as trees, hills and buildings. Reflected and deflected signals generally are out of phase with the carrier wave and cause ghost images, and can lead to complete cancellation. Cancellation and absorption lead to dead spots where no signal can be picked up.

The phenomena noted are of particular importance in the so called fringe areas of reception. In such areas change in location of the receiving antenna of a few feet or less may mean the difference between satisfactory and unsatisfactory reception, or no reception at all. Antenna installations can be located satisfactorily only through trial and error, and once the correct location is found it is undesirable to have to move test equipment and then set up a permanent antenna installation due to the labor involved and inasmuch as the antenna location may be varied inadvertently a sufficient degree as to cause poor reception or no reception. Once a permanent installation been made, it is essential that swaying and rotation in the wind be precluded to avoid spurious signals and fluttering images.

Accordingly, it is an object of this invention to provide an improved and permanent telescoping antenna mast and tower adapted for ready portability and positioning prior to permanent installation.

It is a further object of this invention to provide an antenna mast or tower which is proof against bending and twisting in the wind.

Another object of this invention is to provide a telescoping antenna mast or tower having a combination brace and housing for telescoping mechanism.

A final object is to provide superior antenna mast or tower positioning and raising mechanism.

Other and further objects and advantages of the present invention will be apparent from the following description when taken in connection with the accompanying drawings wherein:

Fig. 1 is a perspective view of my improved mast and a trailer for transporting and erecting the same;

Fig. 2 is a fragmentary perspective view of the mast with the guard channel removed;

Fig. 3 is a cross sectional view taken along the 33 of Fig. 2;

Fig. 4 is a fragmentary longitudinal sectional view of the mast and the adjacent part of the trailer as taken along the line 44 of Fig. 1;

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2,822,067 i atented Feb. 4, 1958 5-5 of Fig. 4; V

Fig. 6 is a fragmentary longitudinal sectional view along the line 6-6 of Fig. 5;

Fig. 7 is a view similar to Fig. 2 with the guard channel in place; and

Fig. 8 is a cross-sectional view along the line 8-8 of Fig. 7.

Referring first to Fig. 1, there is shown a trailer 10 carrying an antenna mast 12. The trailer comprises a rectangular frame 14 formed of steel channels as best may be seen in Fig. 4. A sheet metal floor 16 is mounted on theframe by means such as welding. A pair of wheels 18 are rotatably mounted on the frame and are partially covered by sheet metal fenders 20. A pair of frame members 22 (only one being shown) extend forwardly in the shape of a triangle from the frame 14 to a trailer hitch connection (not shown) of conventional construction. 7

The trailer further is provided at the rear end and at the front of the triangularly shaped frame 22 (the latter not being shown) with vertically disposed sleeves or collars 24 slidably mounting legs 26 having feet 28. Levers 30 have shanks threaded into nut members 32 on the sleeves or collars 24 and communicate with the interior of the sleeves to clamp against the legs 26 to lock them in raised position for traveling or in lowered position, as shown, for bracing the trailer in stationary position while the mast. 12 is raised. v

A substantially A-shaped frame 34 comprising apair of angularly disposed tubular members 36 joined together at and near the top by transverse tubular members 38 and 40 extends upwardly from the rear corners of the frame 14 of the trailer 10. The frame is braced in'its upstanding position by an angularly disposed tubular member 42 fixed to the foremost frame member 14 and connected by a suitable T connector to a sleeve 44 fittin over the tubular member 40.

An elongated channel member 46 is welded to a plate 48 which is suitably fixed to a sleeve 50 pivotable about the top tubular member 38. A U-shaped bolt 52 extends outwardly from a back plate 54 at the top of the channel 46 and is held toward the plate 54 by nuts threaded on the ends of the U bolt and positioned behind the back plate 54.

The mast 12 is releasably clamped in the channel by the U bolt 52 and thus is pivotable about the tubular member 38 between horizontal traveling position and vertical and fixed installed position. The mast 12 comprises three telescopic sections, the outermost one 56 of which is hollow and is square in cross section. The outermost mast section 56 is the one that is clamped in the channel 46 by the U bolt 52, the mast section fitting snugly within the channel so as not to rattle or shiftv in position, but not fitting so tightly as to precludeready release. The square outer mast section 56 is provided near its upper end with a lateral opening 58. A U-shaped strip 60 is welded to opposite sides of the section 56 with the bight of the U extending across in front of the opening 58. A grooved pulley 62 is rotatably mounted on a pin 64 extending between the arms of the U-shaped strip and extends part way into the section 56 through the aperture 58 as best may be seen in Figs. 3 and 4. The pulley is spaced from the arms of the U-shaped strip by a sleeve 66 and a collar 68 for proper positioning in the aperture 58.

asaaoa'z Y a. pin. 76 (Figs. 2 and 7) extendingthrough one of the straps 72 and into an aperture in the Windlass 70. The pin 76 preferably is secured against loss by means such as: a chain 78- or other flexible member fastened to the pin 76 and to a fixed eye 80 or the like.

The intermediate mast section 82 is circular in cross section and telescopic within the outer mast section 56. Rotation of the intermediate mast section 82 relative to the outer mast section 56 is precluded by flattening the lower end of the intermediate mast section 82 to form a spade-like tip 84. As best seen in Figs. and 6 the spade-like tip 84 is of sufiicient size to fit snugly, but slidably, in a diagonal position in the outer mastv section 56. The diagonal fit of'the spade-like tip 84 in the outermost mast section 56 positively precludes any chance of rotation between the intermediate and outer mast sections.

I A cable 86 is fixed to the intermediate mast section 82 near the lower end thereof by a threaded stud 88 or other suitable means and extends upwardly through the square section 56 in a corner thereof as best seen in Figs. 3 and 8 and over the pulley 62, the pulley being positioned toward one side of. the outer section 56 to insure positioning of the cable in a corner. of. the outer mast section. The cable 86 passes downwardly from the pulley 62 through a series of eyelets 90 on the outside of the mastsection 56 to. the Windlass 70 to which it is attached. Rotation. of the Windlass with. the mast 12 in verticalposition obviously will raise or lower the intermediate mast section. 82.

An elongated, U-shaped. channel member 92. extends substantially from the Windlass 70 to the pulley 62 as may be seen in. Figs. 1, 4, and 7, the channel having been omitted from- Fig. 2 for illustrative purposes. The channel 92 houses the cable 86' and protects it against damage and furthermore acts as a bracemember preventing swaying or bending of the outermost mast section 56. The bracing feature of the channel member obviates the necessity of guy wiresv for all but the highest masts and most exposed. locations. The lack of necessity for guy wires which are unsightly, expensive, and difiicult. to install is an advantage the merits of which are believed to be obvious.

A sleeve 94 of reduced diameter is fixed at the upper end of the intermediate mast section 82 and slidably receivesan inner, upper tubular mast section 96' adapted to carry a television antenna 98. Lever members 100 have shanks threaded through nut members 102 in the sleeve section 94 and adapted to engage against the upper tubular mast section 96 to lock the same in place relative to the intermediate mast section 82.

A pair of plates 104 (Figs. 1 and 4) is welded to the top of the rear trailer member 14in spaced apart rclationito receive the outer mast section 56 with the mast inupright position. The plates 104 are provided with. aligned apertures near their outer ends to receive the shank. of an L.-shaped retaining pin 106' for locking. the mast inupright. position. The L-shaped retainingpin 106 is, in turn,,held in place by a spring member 108 resiliently clamping the arm of the lever against one of the plates 104.

A Windlass 110 is rotatably mounted between the opposite ends ofthe plates 104 on an elongated. shaft 112having. a crankarm 114'. A bar 116 pivoted on a support-.118 abuts aside frame member 14 to engage the crank a-rm 114 for preventing unauthorized reverse rotation. thereof.

A cable 120 wound on the Windlass 110 extends through a slot 122 in the floor of the trailer and is secured by a clamp 124 to a clevis 126. The clevis is pivotally secured to an ear 128 which is welded or otherwise. suitably secured to the outer mast section 56 at thev bottom thereof. A. roller 1-30. is rotatably mounted. in. suitable. brackets 1'32onthebottom offthe rear-frame piece 14andis adapted for. engagement. by, the. cable. 12cm raising and lowering the masters wilfbe apparent shortly.

A base member 134 is provided for permanent installation of the mast and comprises a fiat metal plate 136 having a square plug 138 upstanding therefrom. The plug 138 is designed to fit snugly in the bottom of the outer mast section 56. The opposite ends of the plate 136 are apertured for the receipt of spikes 140 for anchoring the plate to the ground.

For transportation the mast 12' is carried in horizontal position on the trailer 10, the upper end of the mast being supported by a stand (not shown) at the forward end of the triangular frame section 22. The cable 120 at this time passes under the roller 130- in engagement therewith. In order to erect and install the mast, the Windlass is rotated bymeans'of the crank 112', 114. This pulls the lower end of the mast generally toward the roller 130 and Windlass 110 to pivot the mast about the sleeve connection 50, 38 to erect the mast. When the mast is first erected, the bottom of the mast is above the ground as shown in. Fig.v 1, and may be evenhigher than shown in Fig: 1. The channel 46 abuts the sleeve 44 on the horizontal. tubular member 40 to. determine the upright position of the mast which is locked in upright position by'the pin;106. Prior to such erection to vertical position, the. upper mast section 96 is pulled out of the sleeve 94 as far as necessary and is locked in position by the clamping: levers 100.

Rotation; of. the Windlass 70 causes a pull on the cable 86: which. causes the intermediate mast section 82 to be moved. vertically upwardly within. the outer mast section 56.. The trailer then. can be moved around, and the upper two mast sections can be moved up and down by means of the Windlass 70 to determine the best possible location for the antenna 98. The legs 26 of the trailer 10 then are lowered and locked in position as shown in Fig, l andthe mast thenis lowered vertically by the windlass- 110' until the bottom reaches the ground, the U-shaped clamp 52. having. been loosened for this purpose. The mast 12 isguyed by a minimum number of guy wires or is braced against a house or other convenient building. After this, the U-bolt 52' can be removed entirely, pin 106 can be removed and the clamp 124 can be loosened to remove the cable and free the mast completely from the trailer. The trailer then can be driven away to have another mast put on it temporarily, and the aforementioned mast 12 remains as a permanent installation.

The square configuration of the outer mast section coupled. with the spade-like tip of the intermediate mast section. positively precludes twisting or relative rotation of these two sections. The U-shaped channel member serves as. a guard for the telescoping cable 86 and also serves as a. brace member tending to prevent bending of the. lowermost. mast. section and thus reducing the need for guy wires to a minimum and. frequently eliminating the need completely. The mast can be moved around at wiIl properly to. positionan antenna and the mast then can be secured permanently in place so that therev is no guesswork in establishing. the optimum antenna location and. orientation. The mast raising mechanism on the trailer is of markedly superior construction in that the same mechanism operates without modification and without disconnection and reconnection both to pivot the mast into vertical position and to lower the mast into permanently installedposition.

The particular form ofv the invention shown and described herein is for illustrative purposes only. Various modifications will. be apparent to those skilled in the art, and it isto. be understood that the invention includes all that which falls clearly within the spirit and scope of the appended claims.

I claim:

1. An antenna mast structure for supporting apositionresponsive antenna.- comprising an outer hollow mast sectionhaving a square cross section, a tubular mast section of ring-like cross section fitting'within said hollow mast section and having a portion flattened to fit across the diagonal of said hollow mast section for preventing relative rotation of said mast sections, means for relatively telescoping said two mast sections, and means for locking said two mast sections in any one of various telescoped positions.

2. An antenna mast structure for supporting a position-responsive antenna comprising an outer hollow mast section having a square cross section, a tubular mast section of ring-like cross section fitting within said hollow section and having a flattened portion at the lower end thereof fitting diagonally across said hollow section between opposite corners thereof, a cable attached to said tubular mast section near the lower end thereof and extending through said hollow mast section in a corner of said square cross section, a pulley adjacent the top of said hollow section and over which said cable passes, a windlass on said hollow section near the lower end thereof and attached to said cable for relatively telescoping said two mast sections, and means for locking said Windlass whereby the two mast sections are held in any one of various telescoped positions.

3. An antenna mast structure for supporting a positionresponsive antenna comprising an outer hollow mast section having a square cross section, a tubular mast section of ring-like cross section fitting within said hollow section and having a flattened portion at the lower end thereof fitting diagonally across said hollow section between opposite comers thereof, a cable attached to said tubular mast section near the lower end thereof and extending through said hollow mast section in a corner of said square cross section, a pulley adjacent the top of said hollow section and over which said cable passes, a windlass on said hollow section near the lower end thereof and attached to said cable for relatively telescoping said two mast sections, and an elongated channel-shaped member secured longitudinally along the outside of said hollow mast section and enclosing said cable substantially between said windlass and said pulley.

References Cited in the file of this patent UNITED STATES PATENTS 459,613 Newman Sept. 15, 1891 989,069 Siewert Apr. 11, 1911 1,213,242 Overly Jan. 23, 1917 1,250,108 Seymour Dec. 11, 1917 1,418,775 Brown June 6, 1922 2,379,333 Athy June 26, 1945 2,551,286 Poetker May 1, 1951 2,611,456 Bader Sept. 23, 1952 2,611,580 Troche et al. Sept. 23, 1952 2,639,381 Thompson et al. May 19, 1953 2,676,677 Anderson et al Apr. 27, 1954 FOREIGN PATENTS 178,145 Switzerland Sept. 2, 1935

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