CA2062544C - Antenna mounting structure with a tiltable bracket - Google Patents

Abstract

A bracket for securing an antenna to a support structure, comprising a first plate member, a second plate member, a pivot for connecting the second plate member to the first plate member, U-bolts for mounting the first plate member to the support structure adjacent the pivot, and further means for attaching the antenna to the second plate member adjacent the pivot, whereby the antenna may be tilted upwardly and downwardly relative to the support structure.

Description

2062~44 FIELD OF THE INVENTION
This invention relates in general to antennas, and more particularly to a tiltable bracket for mounting a telecommunications antenna to a support structure.

BACKGROUND OF THE INVENTION
It is common practice to mount cellular telephone antennas on a stationary support structure, such as a pipe, disposed at an elevated location (e.g., on top of a building).
Prior art antenna mounting brackets are known for mounting a telecommunications antenna to a support structure for providing a limited degree of tilt adjustment to the antenna. However, such prior art mechanical brackets are of bulky and complex construction, often incorporating articulated arms, and require a large amount of space on the support structure in order to be mounted. Therefore, it is difficult to mount more than relatively few of such prior art brackets to the support structure without experiencing wind and weight loading problems. Often, the support structure for such prior art antenna mounting brackets must be reinforced such as by adding tripod legs, etc.
Furthermore, the increasing numbers of such mounted cellular antennas has resulted in public outcry against the unattractive and cluttered appearance of such structures.
Another prior art antenna mounting bracket is disclosed in Canadian Laid-Open Application No. 2,011,328 filed on March 2, 1990 in the name of Roy Telecommunications Ltee. The bracket described in this patent application incorporates a pipe having a bracket mounted to the end thereof. The pipe is adapted to be attached to the supporting structure (e.g. tower, tripod, etc.). The bracket incorporates a hole for receiving a ~ 2~62~

:~ - 2 -bolt which is adapted to pass through the end of a mounting pipe of an antenna to be mounted. An arcuate slot is provided to receive a further bolt which is adapted to pass through the attachment pipe of the antenna such that the tilt angle of the antenna may be adjusted. Two significant disadvantages of this prior art antenna mounting bracket are that the degree o~
adjustable tilting is very limited and the bracket is not capable of tilting the antenna upwardly. Se~ondly, since the brackct is said to be mounted to the supporting structure via an elongated pipe, a large amount of space is occupied on the supporting structure ~or mounting of the bracket such that very few, if any~ additional antennas may be mounted on the support structureO
- SUMMARY 0~ THE INVENTION
According to the present invention, a tiltable antenna mounting bracket is provided in which the ~astening point for the bracket to the supporting structure is located immediately adjacent the pivot point of the bracket. The attachment point occupies v~ry little space such that an antenna may be easily mounted to a supporting structure on which other antennas are already disposedl or multiple antennas may be provided on a single support structure using the bracket of the present invention due to its extremely compact size.
The reduced size and complexity of the bracket according to the present invention results in very low wind and weight loading on the support structure as compared to prior art antenna mounting brackets.
Furthermore, as a result of the reduced size of the mounting bracket of the present invention, the bracket may be mounted behind the antenna so as to be shielded from view, thereby contributing to overcoming the prior art disadvantage of public complaints against the unattractive appearance of such structures.

2 ~

An additional feature of the present invention is the provision of two pairs of arcuate slots located on opposite sides of the pivot point such that tilting o~
the ~ntenna mounting pipe can be adjusted upwardly and downwardly. Some prior art antennas are known to incorporate downward radiation patterns for example, one prior art antenna has a 45~ beam width and an au-tomatic tilt of 15~ (downward). There~ore, by using the antenna mounting bracket of the present invention, which is characterized by a large range of adju~table tilt angles, it is possible to mount the prior art 45~ antenna and compensate ~or the 15~ tilt of the antenna to accommodate other tilt angles ~13~, etc.). This results from the ability of the mounting bracket according to the present invention to tilt the antenna both upwardly and downwardly.
According to a general aspect of the present invention, there is provided a bracket for securing an antenna to a support structure, comprisingo a first plate member; a second plate member; pivot means Por connecting said second plate member to said first plate member;
means for mounting said first plate m~- h~r to said support structure adjacent said pivot means; and means for attaching said antenna to said second plate member adjacent said pivot means, whereby said antenna may be tilted upwardly and downwardly relative to said support structure.

BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description o~ the pre~erred embodiment is provided herein below with rePerence to the following drawings, in which:
Figure 1 is a parspective view oP the antenna mounting bracket according to the present invention for mounting an antenna to a support structure;

Figure 2 is a perspective exploded view of the mounting bracket according to the preferred embodiment;
and Figures 3A and 3B illustrate dsgrees of tilt 5 adjustment of the antenna mounting bracket according to the preferred embodiment.

DETAILED DESCRIPTION OF THE PREFE:RRED EMBODIMENT
Turning to Figure 1, the mounting bracket 1 o~
the present invention is shown for mounting an antenna to a support structure 3. The support structure 3 is typically mounted adjacent the rooftop edge of a building, or mounted to an antenna tower, etc. In the usual manner t the antenna 2 i5 provided with a pole member 5 align~d parallel to the major axis of the antenna 2.
Turning to Fiyure 2, construction of the mounting bracket 1 of the present invention is shown in greater detail ~omprising a first plate member 7 and second plate member ~. The first plate member 7 comprise~ a rectangular base plate 11 having a generally tongue-shaped member 13 projecting orthogonal thereto.
Likewise, the second plate member 9 includes a rectangular base plate 15 and orthogonal generally tongue-shaped member 17 projecting therefrom. Top gusset plates 16A and 18A, and bottom ~usset plates 16B ~nd 18B
are provided ~or reinforcing the connection between tongue-shaped member~ 13 and 17 to respective rectangular plates 11 and 15. A pivot is provided in the form of a hole l9A, 198 through the centre of each of the tongue-shaped members 13 and 17 for receiving a bolt 21 and nut 23, thereby providing pivotal connection between the first plate member 7 and second plate member 9.
A pair of arcuate slots 25A, 25B are provided in tongue-shaped member 13, and a similar pair of arcuate slots 27A, 27B are provided in ~he second tongue-~haped member 17. When in assembled form ~Figures 1 and 3), the ' , . :, slots 25A, and 27A overlap at least partially, so as to receive a ~olt 29 to which is attached a nut 30 and washer 31. Similarly, the slots 25B and 27B at least partially overlap in assembled form so as to receive a bolt 32 to which is attached nut 33 and washer 34. The base plate 11 includes a first two pairs o~ holes 35 for receiving U-bolts 37 and 39, whereby a base plate 11 may be attached to supportin~ structure 3 via the bolt~ 37 an~ 39 and associated nuts 41.
An additional two pairs of holes 43 are provided for accommodating a larger A; -nsion of U-bolt (not shown) in order to attach the antenna mounting bracket 1 to a larger diameter of supporting structure 3.
Base plate 15 includes two pairs of holes 45 for receiving two U-bolts 47 and 49 and accompanying nuts 51, whereby the plate member 9 may be attached to the antenna pole member 5.
A significant ~eature of the present invention is that the hole pairs 43 and 35 are located , -~iately behind the pivot l9A, 19B so that the bracket may be mounted so as to occupy minimal spa&e on the support structure 3. Therefore, the mounting structure 3 can be loaded with a larger num~er of antPnn~.S using the bracket o~ the present invention than would be possible using prior art brackets.
A second significant feature o~ the invention is that the plurality of holes 45 in the base pl~te 15 are also spaced equidistant from the pivot hole l9A, l9B
such that the pole member 5 o~ antenna 2 is mounted directly beh.ind the pivot l9A, l9B. Therefore, the antenna 2 can be tilted upwardly or downwardly over a broad range of angles as shown best in Figures 3A and 3B.
Adjustable tilting of the antenna 2 is accomplished by simply loosening the nuts 23, 30, and 33 so that plate member 9 may be rotated relative to stationary plate member 7. Once a desired tilt angle is established, the nuts 23, 30, and 33 are then tightened for locking the 2~Sl~

bracket 1 at the desired angle. Preferably, each of the arcuate slots 25A,B and 27~tB span an arc of approximately 40~ relative to the holes l9A, 1~.
In summary, according to the present invention an antenna mounting bracket is provid~d which is chara~terised by simple and rugged construction consuming very little ~pace. The bracket is mounted to a supporting structure ; ~liately ~ehind the 501e pivot point such that the bracket occupies very little space on the supporting structure, thereby enabling a large numbPr o~ antennas to be mounted to a single support structure.
Also, the antenna 2 is mounted to the bracket 1 at a location i e~ately behind the pivot, so that a large range of tilt angles may be selected.
Other modi~ications and variations of the invention are possible. For example, although the attachment means discussed herein are U-bolts, other attachment ~eans such as clamps r etc. may be utilized.
Furthermore, although the preferred embodiment relates to mounting of telecommunications antenna such as antennas for cellular telephones, the bracket may be utilizad to mount microwave ankennas or other devices reguiring accurate tilt adjustment. All such modifications and alternatives are believed to be within the sphere and scope of the invention as defined by the claims appended hereto.

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Claims (7)

1. A bracket for securing an antenna to a support structure, comprising:
a first plate member;
a second plate member;
pivot means for rotatably connecting said second plate member to said first plate member;
means for mounting said first plate member to said support structure adjacent said pivot means; and means for attaching said antenna to said second plate member adjacent said pivot means, whereby said antenna may be tilted upwardly and downwardly via said pivot means relative to said support structure.

2. The bracket of claim 1 wherein said means for mounting comprising a base plate having at least two pairs of holes passing therethrough, said at least two pairs holes being spaced equidistant from said pivot means, and a plurality of U-bolts passing through said holes and around said support structure for securing said base plate to said support structure.

3. The bracket of claim 1 wherein said antenna includes a pole member aligned parallel to the vertical axis of said antenna, and wherein said means for attaching comprises a base plate having at least two pairs of holes passing therethrough, said at least two pairs of holes being spaced equidistant from said pivot means, and a plurality of U-bolts passing through said holes and around said pole member at approximately the centre thereof for securing said base to said pole member for effecting upward and downward tilting of said antenna.

4. The bracket of claim 1 wherein each of said first plate member and said second plate member comprises generally tongue-shaped planar portions connected orthogonally to respective base plates.

5. The bracket of claim 4 wherein said pivot means comprises a centrally disposed hole in each of said first and second plate members, said hole in each of said first and second plate members being aligned coaxially, and a central bolt passing through each said hole for effecting pivotal movement of said first and second plate members around said hole.

6. The bracket of claim 5 further including a pair of arcuate slots on opposite sides of said hole in each of said first and second pairs of plate members, and a pair of additional bolts passing through respective ones of said slots in each of said first and second plate members for locking said first and second plate members in selectable angular positions.

7. The bracket of claim 6 wherein said pair of arcuate slots span an arc of approximately 40° relative to said hole.