Antenna tower

Abstract

An antenna tower for television antennas or the like has an anchoring unit, a lower stationary mast and an upper, movable mast. The anchoring unit and each of the masts have a pair of rigid, upright, parallel posts having upper ends rigidly interconnected by spanning members. The stationary mast has a brace which extends between its posts and is fixed to the anchoring unit to structurally reinforce anchoring unit and mast. The movable mast is pivotally mounted to the top of the stationary mast for swinging movement about a horizontal axis between a generally vertical operating position and an inclined position permitting maintenance to the upper end of the movable mast. A pair of bolts releasably retains the lower end of the movable mast to the anchoring unit, keeping the movable mast in upright operating position.

Description

SUMMARY OF THE INVENTION

The invention relates to the field of antenna towers and comprises a tower with an upper mast pivotally mounted to a four-post tower base possessing structural features producing unusual strength and mutual reinforcement to the members forming the tower.

A generally upright, stationary anchoring unit has a first pair of upright, rigid posts which are spaced apart and solidly anchored to the earth or concrete, the longitudinal axes of the posts defining a first generally vertical plane. An upright stationary mast has a second pair of upright posts which are anchored to the earth or concrete and are parallel to the posts of the anchoring unit, extending substantially higher than the anchoring unit. The longitudinal axes of the posts of the stationary mast define a second generally vertical plane which is preferably substantially perpendicular to the first plane. A rigid brace extends between the posts of the stationary mast and is rigidly fixed to the upper end of the anchoring unit, causing the anchoring unit and the upright mast to reinforce each other to resist bending of the posts of the stationary mast or the anchoring unit. The upper end of the stationary mast has a spanning member extending between the posts and rigidly fixed to each; a generally horizontal rod is welded to the spanning member and provides a pivotal mounting about which an elongate, movable mast is pivotally mounted. The movable mast extends from the level of the anchoring unit to a point substantially above the stationary mast and swings about the longitudinal horizontal axis of the rod from a generally vertical operating position to an inclined maintenance position wherein the upper end of the mast is lowered adjacent ground level to permit maintenance at the upper end of the mast. An antenna mount is attached to the spanning member at the upper end of the movable mast to receive and retain an antenna. Means are provided to releasably selectively retain the movable mast to the anchoring unit in the vertical operating position.

A bridging member interconnects the lower ends of the posts forming the movable mast and partially encompasses one of the posts of the stationary mast when the movable mast is retained against the anchoring unit, thereby providing structural support and reinforcement to the movable mast and the anchoring unit. A spanning member rigidly connects the upper ends of the posts of the anchoring unit. The movable mast is pivotally mounted to the stationary mast with the center of gravity of the movable mast being above the stationary mast when in operating position; a counterweight is attached to the lower end of the movable mast to counterbalance the upper end of the mast, thereby facilitating swingably lowering the movable mast for maintenance of the antenna.

The invention is particularly useful in mounting antennas high above ground level as is required in many outlying areas having weak radio and television reception. Because the movable mast is easily lowered, the tower construction permits convenient manipulation of the antenna's orientation to thereby obtain optimum reception of the television or radio signal. The unusual strength and reinforcement characteristics of the tower make it resistant to adverse weather conditions.

The antenna tower is economical to manufacture and simple to install. Its sturdy construction and reinforcement characteristics assure long life and safe and reliable operation. These and other advantages will appear from the further description and appended drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective drawing of the antenna tower showing the movable mast in operating and maintenance positions.

FIG. 2 is a cross-sectional top view of the lower portion of the tower of FIG. 1 taken in the direction of cutting plane 2--2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, an antenna tower 10 embodying the invention has an anchoring unit 12, a stationary lower mast 14, and a movable, upper mast 16.

The anchoring unit 12 includes a first pair of generally upright, rigid posts 18 and 20, which are spaced apart from one another and have their lower ends rigidly retained in concrete block 22. While it is preferred that a concrete block be used to retain the lower ends of the posts of the anchoring unit and also of the stationary mast 14, the invention can function satisfactorily if the posts are embedded firmly in the earth.

The upper ends 21 and 23 of posts 18 and 20, respectively, are interconnected by a first spanning member 24 which rigidly interconnects the posts to strengthen and support them. The shown preferred spanning member 24 is formed of two sections of tubular pipe welded together and to the upper ends of the posts 18 and 20, the sections 25 and 26 of the spanning member 24 meeting at apex 27 for a purpose described hereafter. If desired, the spanning member 24 may be replaced by a U-shaped member rigidly welded to the upper ends 21 and 23, or by a bar extending between the upper ends, and such alternative spanning members are within the purview of the invention.

The posts 18 and 20 interconnected in some manner adjacent their upper ends 21 and 23 by spanning member 24 collectively comprise the stationary anchoring unit 12. The posts 18 and 20 and spanning unit 24 are preferably formed of rigid, metallic, tubular pipe, although other equivalent materials known to the art may be substituted.

The upright stationary mast 14 has a second pair of generally upright, rigid, parallel posts 28 and 30 spaced apart from one another and having their lower ends rigidly retained in the concrete block 22. As shown in FIG. 1, the posts 28 and 30 extend substantially higher than the anchoring unit and have their upper ends 32 and 34 connected to one another by a second spanning member 35. The shown spanning member 35 is formed of intersecting sections 36 and 37 rigidly attached to each other at apex 38 and to the upper ends 32 and 34 of the posts by welding or equivalent means. Although the shown spanning member 35 comprised of sections 37 and 36 is preferred, it should be understood that a U-shaped spanning member or other interconnecting member extending between the posts 28 and 30 may be used and is within the purview of the invention.

Posts 28 and 30 interconnected adjacent their upper ends 32 and 34 by second spanning member 35 collectively comprise stationary mast 14. The mast may be formed of tubular pipe sections like those described for the anchoring unit or may be made of other rigid material known to the art. Posts 18, 20, 28 and 30 are substantially mutually parallel to one another. The longitudinal axes 40 and 41 of the circular cross-section posts 18 and 20, respectively, define a first generally vertical upright plane 44 when the tower 10 is installed. The longitudinal axes 42 and 43 of the posts 28 and 30, respectively, define a second generally vertical plane 45. The first and second pairs of posts are positioned in the concrete block 22 or earth such that the first and second planes 44 and 45 are transverse to one another, and it is preferred that the planes in fact be perpendicular to one another to obtain maximum strength and reinforcement for the anchoring unit 12 and the stationary mast 14.

To provide additional stability and strength for the tower the posts 18 and 20 have been positioned substantially along one diagonal of the concrete block 22 and the posts 28 and 30 postioned along the remaining intersecting diagonal of the block 22 as best shown in FIG. 2.

A rigid metal brace 46 extends between the posts 28 and 30 and is rigidly fixed to each of the posts. The apex 27 of the first spanning member 24 closely overlies the brace 46 and is welded thereto or attached by other means known to the art, resulting in a structure of great strength wherein the anchoring unit supports and reinforces the stationary mast 14, defining a four-post tower base resistant to bending of the posts. Interconnecting mast 14 and anchoring unit 12 substantially limits swaying and lateral movement of the mast 14 in directions perpendicular to the plane 45. The stationary mast 14 has a reinforcing and supporting effect on the anchoring unit 12, the brace 46 substantially limiting movement of the anchoring unit 12 in directions perpendicular to plane 44.

A rigid rod or pipe 46' is attached to the spanning member 35 and passes through sockets in the posts 48 and 50 of movable mast 16 to pivotally connect the mast 16 to the stationary mast 14, the longitudinal axis 51 of the rod 46' being generally horizontal. Nuts or caps 53 prevent escape of the posts 48 and 50 from the rod 46.

The movable mast 16 includes a pair of generally parallel, upright rigid posts 48 and 50 mounted for swinging movement about a generally horizontal axis 51 from an upright generally vertical operating position 52 to an inclined maintenance position where the upper end of the mast 16 is adjacent ground level to permit maintenance at the upper end of the mast. It is preferred that the mast 16 extend from the anchoring unit substantially above the top of the stationary mast to raise the antenna to be described hereafter to a high level thereby obtaining better television or radio reception.

The upper ends 54 and 56 of the posts 48 and 50, respectively, are interconnected by a third spanning member 58 made up of sections 60 and 62 which are welded to the upper ends 54 and 56, respectively, of the posts and to each other at apex 64, the sections 60 and 62 as well as the posts 48 and 50 being formed of rigid commercially available tubular pipe. While the particular spanning member shown in FIG. 1 is preferred, it should be understood that other types of spanning members utilizing a U-shape construction or alternatively a simple interconnecting straight member extending between the posts 48 and 50 may be substituted and are within the purview of the invention. Accordingly the posts 48 and 50 and the spanning unit 58 comprise one embodiment of a movable mast 16 usable with the invention.

A hollow pipe 66 is rigidly attached to and extends upwardly from the apex 64 of the movable mast, the pipe 66 being generally parallel to posts 48 and 50. A commercially available television antenna 70 with a pole 72 is inserted within the tubular pipe 66 and rigidly held therein by means of setscrews 74. The pipe 66 and setscrews 74 collectively comprise an antenna mount.

The lower ends 76 and 78 of posts 48 and 50, respectively, have exposed hollow terminal ends to permit the insertion of weighted metal bars 80 and 82 which comprise a counterweight for the movable mast 16 and counterbalance the otherwise heavier upper section of the mast 16 situated above the axis 51. It should be understood that the object is to have the section of mast 16 above the axis 51 heavier than that positioned below the axis so that the mast will tip downwardly, but the difference in weight should be small so that the upper section will drop gradually and can be easily controlled by a rope attached to the lower end of the mast 16 as will be described hereafter. The counterweight bars 80 and 82 may be secured within the posts 48 and 50 in any manner known to the art, such as setscrews, force fit, or welding.

A bridging member 84 is rigidly attached to and extends between the posts 48 and 50, lying within a plane generally perpendicular to the plane 44 defined by the longitudinal axes of posts 48 and 50. The bridging member 84 includes transverse sections 86 and 88 welded rigidly to the posts 48 and 50 and converging sections 90 and 92 which are rigidly welded to the sections 86 and 88 and to each other at apex 94. The sections 86, 88, 90 and 92 are shaped and assembled to partially encompass the post 28 of stationary mast 14, permitting the posts 48 and 50 to be brought into close parallel engagement with the posts 18 and 20 of anchoring unit 12, the anchoring unit 12 being positioned in the block 22 such that the posts 48 and 50 when brought into contact with the anchoring unit will lie in a generally vertical plane. Accordingly the anchoring unit 12 is positioned closer to the post 30 than to the post 28.

A bolt 96 is passed through each bore 98 in posts 48 and 50 and then through aligned bore 100 in posts 18 and 20, a nut 102 being tightly secured on each bolt 96 to keep the posts 48 and 50 in tight engagement against posts 18 and 20. The shown nuts, bolts, and bores comprise one means useful in releasably retaining the movable mast to the anchoring unit in the vertical operating position, although it should be understood that other means known to the art may be substituted and are within the purview of the invention.

A loop 104 extends outwardly from the bridging member 84 to permit attachment of a rope usable by an operator to raise and lower the movable mast 16.

In operation, when the mast has been erected as shown in FIG. 1 and the television antenna is to be inserted and adjusted, an operator removes the bolts 96 and nuts 102, releasing the lower ends of posts 48 and 50 from anchoring unit 12. After securing a rope 105 about the loop 104 and retaining the remaining end of the rope, the operator plays out the rope permitting the lower end of the mast 16 to slowly move upward, resulting in the movable mast 16 pivoting about the horizontal axis 51, swinging from the upright vertical position 52 to an inclined maintenance position 71. When the upper end is at the desired distance above the ground the operator may secure the rope to the member 46 and then insert the antenna pole 72 within the pipe 66, tightening the setscrews 74 against the pole 72 to secure it within the pipe 66. The operator then uses the rope to pull the lower end of the movable mast 16 downward into engagement with the posts 18 and 20 of the anchoring unit 12 and reinserts the bolts 96 through the bores 98 and 100, securing the nuts 102 to the bolts to thereby rigidly retain the posts 48 and 50 against anchoring unit 12.

Accordingly the invention provides a novel antenna tower structure having a movable mast to facilitate placement of the antenna and adjustment thereof. While a particular form or embodiment of the invention has been shown and described herein for illustrative purposes and the construction and arrangement of the components thereof have been disclosed and discussed in detail, it is to be understood that the invention is limited neither to the mere details or relative arrangement of parts, nor to its specific embodiment shown herein, but that extensive deviations from the illustrated form or embodiment of the invention may be made without departing from the spirit of the invention.

Claims

What is claimed is:

1. An antenna tower mounted on the ground for supporting an antenna comprising:

a generally upright, stationary anchoring unit including a first pair of upright rigid posts spaced apart and having lower ends rigidly retained on the ground, the longitudinal axes of said first pair of posts defining a first generally vertical plane when said unit is mounted on the ground;

a generally upright, stationary mast including a second pair of upright rigid posts spaced apart from each other and extending upwardly substantially farther than said anchoring unit, the upper ends of said second pair of posts connected to one another and the lower ends rigidly retained on the ground, the longitudinal axes of said second pair of posts defining a second generally vertical plane when said stationary mast is mounted on the ground, said second plane oriented transversely to said plane;

a rigid brace interconnecting said second pair of posts and fixed to said anchoring unit so that said anchoring unit and said second pair of posts structurally reinforce each other to define a four-post tower base resistant to bending of said first and second pairs of posts;

an elongate, movable mast extending from the level of said anchoring unit substantially above said stationary mast, said movable mast being pivotally connected to said stationary mast adjacent the upper end of said stationary mast to swing about a generally horizontal axis between a generally vertical operating position and an inclined maintenance position, wherein the upper end of said movable mast is lowered adjacent ground level to permit maintenance at the upper end of said movable mast;

means releasably retaining said movable mast to said anchoring unit in said vertical operating position; and

an antenna mount attached to the upper end of said movable mast to receive and retain the antenna.

2. The antenna tower of claim 1 wherein said first and second pairs of posts are substantially parallel to one another and said first and second vertical planes are substantially perpendicular to one another.

3. The antenna tower of claim 2 wherein said movable mast includes a pair of parallel, hollow, tubular posts and a bridging member interconnecting the lower ends of said hollow, tubular posts, and when said movable mast is retained in operating position said bridging member partially encompassing one of said posts of said stationary mast to provide structural support and reinforcement to said movable mast and to said anchoring unit.

4. The antenna tower of claim 1 wherein said anchoring unit includes a first spanning member extending between the upper ends of said first pair of rigid posts and fixed to said brace, reinforcing said first and second pairs of posts to resist bending of the posts.

5. The antenna tower of claim 1 wherein said stationary mast includes a second spanning member rigidly interconnecting the upper ends of said second pair of parallel posts.

6. The antenna tower of claim 1 wherein the center of gravity of said movable mast is above said stationary mast when in vertical operating position, and further including a counterweight attached to the lower end of said movable mast to counterbalance the upper end of said movable mast to facilitate lowering of said movable mast for maintenance.

7. The antenna tower of claim 6 wherein said movable mast includes a pair of parallel, hollow, tubular posts and said counterweight includes a pair of weighted bars, a bar being retained within the lower end of each of said hollow, tubular posts.

8. The antenna tower of claim 7 wherein said movable mast includes a third spanning member rigidly interconnecting the upper ends of said pair of parallel, hollow, tubular posts and said antenna mount is rigidly fixed to said third spanning member.