WO2002001669A1

WO2002001669A1 - Improvements for cellular radio telecommunication relay antenna masts

Info

Publication number: WO2002001669A1
Application number: PCT/FR2001/002032
Authority: WO
Inventors: Georges Tarrisse
Original assignee: Bouygues Telecom
Priority date: 2000-06-27
Filing date: 2001-06-27
Publication date: 2002-01-03
Also published as: FR2810798A1; FR2810798B1

Abstract

The invention concerns an assembly forming an antenna mast for cellular telecommunication network comprising a substantially vertical mast (1) bearing one or several antennae (2) comprising: means adapted to slide along the mast and whereon an antenna (2) is fixed; at least an endless screw extending along the height of said mast and co-operating with said means to drive the latter in a sliding movement; a mechanism enabling an operator at the foot of the mast to drive in rotation said endless screw to lower the antenna (2) so that the operator at the foot of the mast can perform an intervention on the mast. The invention is characterised in that the mast comprises a main tubular body (1) wherein extends said endless screw and the means for sliding along the mast and whereon the antenna (2) is fixed comprise a mobile unit arranged inside said tubular body and at least a fixing portion extending from said mobile unit and passing through said mast (1) at an orifice which extends in the height thereof.

Description

IMPROVEMENTS TO MATS OF CELLULAR RADIO-TELECOMMUNICATION RELAY ANTENNAS

TECHNICAL FIELD OF THE INVENTION

The present invention relates to masts of relay antennas for cellular radio-telecommunications system.

Conventionally, in urban areas, the masts of relay antennas are located on elevated sites such as terraces of buildings and can have a height of up to 4 meters, or even beyond.

It is necessary to be able to intervene regularly on the antennas carried by these masts in order to carry out their maintenance and to adjust their orientation, both in elevation (Tilt adjustment), in azimuth, and in verticality. Currently, such interventions are made by climbing on the mast, the intervention personnel using for this purpose the rungs and anchoring points distributed on the masts, as well as personal protective equipment intended to secure the intervention.

GENERAL PRESENTATION OF THE INVENTION

The invention, for its part, proposes a structure of an assembly forming an antenna mast which makes it possible to improve the security of interventions on the antennas of cellular telecommunications networks and has the advantage of greatly simplifying the equipment which the personnel (absence of harnesses, lanyards, etc.).

In particular, the solution proposed by the invention allows personnel to intervene on the antenna (s) fixed on it without having to climb onto the mast, the antenna (s) being capable to be slid along the mast to be lowered to breast height, so that the staff can intervene on that (s) in collective protection, a railing set up on the roof or the terrace sufficient to ensure the safety of the intervention. Note also that this solution eliminates the need to provide on the mast steps and anchor points distributed over the height thereof, which improves the aesthetics of the masts.

The solution proposed by the invention also has the advantage of being particularly simple, of requiring little or no maintenance, of being suitable for outdoor installation and for withstanding weathering.

Yet another advantage of the solution proposed by the invention is that it allows adjustment or maintenance interventions on the antennas with a single person, while the mast structures of the prior art systematically required several people to each intervention, resulting in cost savings.

Thus, the invention provides an assembly forming an antenna mast for cellular telecommunications network comprising a substantially vertical mast which carries one or more antennas. This set includes:

means capable of sliding along the mast and on which at least one antenna is fixed,

- at least one endless screw which extends in the height of said mast and which cooperates with said means to cause them to slide, - a mechanism which allows an operator at the foot of the mast to rotate said screw without end to lower the antenna so as to allow the operator to intervene at the foot of the mast.

The mast comprises a tubular main body in which extends said worm and the means which are able to slide along the mast and on which the antenna is fixed comprise on the one hand a movable block arranged inside said tubular body and on the other hand at least one fixing portion which extends from said movable block and passes through said mast at an opening which extends in the height thereof.

This mast assembly is advantageously completed by the following different characteristics taken alone or in all their possible combinations:

- The tubular body is constituted by two beams of U or similar section reported one facing the other; - It has at each of its ends a sleeve which maintains the beams and which comprises means for maintaining the worm;

- It comprises at the foot of the mast a fixing flange which comprises means allowing the adjustment of the orientation of the mast on itself;

- A sleeve at the foot of the mast has handles allowing an operator to exert on the mast a torque tending to rotate it on itself;

- it includes one or two worms; - It can include if necessary branches forming struts which extend between the mast and fixing studs offset with respect thereto;

- It can include if necessary branches forming struts which are fixed on means capable of sliding along the mast.

PRESENTATION OF THE FIGURES

Other characteristics and advantages of the invention will emerge from the description which follows, which is purely illustrative and not limiting and should be read with reference to the appended drawings in which:

- Figure 1 is a schematic perspective representation of an antenna mast according to a possible embodiment of the invention;

- Figure 2 is a schematic perspective representation of a detail of the antenna mast of Figure 1; - Figure 3 is a top view representation of the means shown in Figure 2;

- Figure 4 is a schematic representation in top view illustrating the principle of a mast carrying three antennas, according to a possible embodiment of the invention; - Figure 5 is a schematic representation illustrating two alternative antenna attachment options; - Figure 6 is a schematic representation in top view illustrating a detail of the means for fixing a mast according to a possible embodiment of the invention.

DESCRIPTION OF ONE OR MORE POSSIBLE EMBODIMENTS

In FIG. 1, there is shown a mast 1 according to a possible embodiment of the invention which at one end carries an antenna 2 and at its other end has a foot 3 by which it is fixed on a metal stud 4.

The mast 1 mainly consists of two beams 1a, 1b, of U-shaped section or the like, attached to one another so as to form a hollow tubular assembly.

These beams 1a, 1b are held one on the other by means of two blocks referenced by 5 and 6 which are arranged at one and at the other of the two ends of the mast 1.

The block 5, disposed in the vicinity of the fixing foot 3, is presented externally, as can be seen more particularly in the figures

2 and 3, in the form of a sleeve 7 which is of an inner section complementary to that of the assembly formed by the two beams 1a,

1b reported one on the other.

Said beams 1a and 1b are fitted into said sleeve 7 and held relative to one another by the walls of the latter.

This sleeve 7 has a bottom 7a from which extend two tubular guides 8 which each receive an endless screw 9, said endless screws 9 extending over the entire height of the two beams 1a and 1b .

These endless screws 9 are also received, at the other end of the mast 1, in holding elements similar to the tubular guides 8, presented by the block 6, which has a structure substantially identical to that of the block 5.

The block 5 also has a mechanism 10 which allows the screws 9 to be driven on themselves by an operator at the foot of the mast 1. This mechanism 10 has for example a threaded rod whose thread meshes with the thread of the endless screws 9, as well as actuation means which open out from the sleeve 7.

It will also be noted, with reference again to FIG. 1, that the mast foot 3 is fixed to the bottom 7a of the sleeve 7 thus forming a single piece.

It ends with a fixing plate 11 forming a flange which is provided, for the installation of bolts ensuring the fixing of said flange 11 and of the foot 3 on the metal stud 4, with oblong lights 12 which allow the adjustment of the orientation of mast 1 around its axis.

Handles 13 which extend on one side and the other of the sleeve 7 allow an operator to exert a force tending to rotate the mast 1 on itself when the fixing bolts are loose.

In an advantageous embodiment, a Teflon disk is provided between the stud 4 and the flange 11 which facilitates the orientation adjustment.

The attachment of the antenna (s) 2 to the mast 1 will now be described.

This fixing is carried out by means of mobile blocks 14 (FIG. 4) which are distributed inside the mast 1, in the height of the latter, and which are capable of sliding in said mast 1, the internal shape of the latter. ci ensuring sliding guidance of said blocks 14.

These blocks 14 are crossed by the screws 9, the threads of which are engaged with complementary threads presented by said blocks 14.

Each block 14 carries two lateral extensions 15 or ears which extend on either side of such a block.

These two extensions 15 open from the mast 1 at the level of the slots which extend in the height of the latter and which are defined by a slight spacing maintained between the two beams 1a and 1b.

Stirrups 16 surrounding the mast 1 on the outside on a half-circumference are fixed at one and the other of their ends on the two extensions 15.

These stirrups 16 carry arms and articulations of antenna attachments known in themselves. More specifically, there is provided in the mast 1 at least two such movable blocks 14, one for fixing the lower part of the antenna (s) 2, the other for fixing their upper part.

In the lower part, the antenna 2 is fixed to the corresponding bracket 16 by means of an arm 17 which extends from said bracket 16. The attachment to said arm 17 allows the antenna to pivot around 2 of a horizontal axis at the end of said arm.

In the upper part, the fixing means comprise an adjustable articulation 18 which makes it possible to tilt the antenna 2 around the horizontal axis defined in the lower part.

As illustrated in FIG. 5, two fixing variants are possible for the upper part of the mast.

In a first variant, the fixing articulation is fixed directly to the antenna, in the vicinity of the upper end of the latter. In a second variant, provision is made for the articulation to be fixed on a retaining plate 19 on which the antenna is fixed at a certain height, in the case where the type of antenna used does not allow such a type of fixing.

This retaining plate 19, also called a universal plate, makes it possible to support the antenna beyond the fixing means 18 and therefore to use a mast of a reduced height than with the solution shown in FIG. 1.

As will be understood, with the structures which have just been described, when an operator wishes to intervene on an antenna for maintenance reasons or to adjust its orientation in Tilt, he actuates the mechanism 10 which is located at the foot of the mast (using for example means of the crank type or the like) so as to rotate the worms on themselves and to lower the movable blocks 14 and the antenna (s) 2. When the block lower mobile is found at block 5, the

(or the) antenna (s) 2 are then at a height which allows the operator to intervene on them while it is at the foot of the mast. The intervention is therefore done in complete safety, only a railing being provided where appropriate when the mast is located on a building terrace.

When he has finished his intervention and carried out a Tilt adjustment or any other operation on the antenna, the operator actuates the mechanism 10 in the opposite direction to reassemble the antenna.

We will now describe complements relating to the fixing of the mast.

It may advantageously be provided on the mast of the attachment branches 20 called "bracons" extending from a point halfway up the mast to metal studs 21 on the ground (Figure 1).

These struts 20 are constituted by telescopic arms fixed at one end to a stirrup 16a attached to a movable block 14a which is disposed in the mast 1 and slides therein in the same way as the blocks 14 (Figure 6).

More specifically, the means by which the bracons 20 are fixed to the stirrup 16a comprise a half-moon hoop 22 attached to said stirrup 16a.

These two struts 20 make it possible to limit the possible bending moments that the mast 1 could support and, if necessary, to adjust the azimuth of the mast.

Claims

1. An antenna mast assembly for a cellular telecommunications network comprising a substantially vertical mast (1) which carries one or more antennas (2), comprising:

- means (14) capable of sliding along the mast and on which at least one antenna is fixed,

- at least one worm (9) which extends in the height of said mast and which cooperates with said means to drive the latter in sliding, - a mechanism (10) which allows an operator at the foot of the mast to driving said worm in rotation to lower the antenna so as to allow operator intervention thereon at the foot of the mast, characterized in that the mast comprises a tubular main body (1) in which s extends said worm (9) and in that the means which are able to slide along the mast and on which the antenna (2) is fixed comprise on the one hand a movable block (14) arranged inside of said tubular body and on the other hand at least one fixing portion (15) which extends from said movable block and passes through said mast at an opening which extends in the height thereof.

2. Assembly according to claim 1, characterized in that the tubular body is constituted by two beams (1a, 1b) of U section or the like attached one facing the other.

3. An assembly according to claim 2, characterized in that it comprises at each of its ends a sleeve (5, 6) which ensures the maintenance of the beams and which comprises means for maintaining the worm.

4. Assembly according to one of the preceding claims, characterized in that it comprises at the foot of the mast a fixing flange (11) which comprises means (12) authorizing the adjustment of the orientation of the mast on itself.

5. An assembly according to claims 3 and 4 taken in combination, characterized in that a sleeve (5) at the foot of the mast has handles allowing an operator to exert on the mast a torque tending to rotate it on itself- even.

6. Assembly according to one of the preceding claims, characterized in that it comprises one or two endless screws (9).

7. Assembly according to one of the preceding claims, characterized in that it can comprise, if necessary, branches (20) forming struts which extend between the mast and fixing studs offset relative to the latter.

8. Assembly according to one of the preceding claims, characterized in that it can, if necessary, branches forming struts which are fixed on means capable of sliding along the mast.