FR2807214A1 - Relay tower for radio transmissions includes parallelogram linkage in upper tower to keep aerial supports at required angle - Google Patents

Abstract

The pylon includes an HF amplifier mounted in the top section, and a parallelogram linkage to maintain angular position. The radio transmitting mast comprises a pylon supporting at least one aerial, with equipment including an HF amplifier mounted in the upper part of the pylon. This equipment is mounted in a profiled box which is solidly attached to the pylon, and provided with power by photoelectric cells mounted on the upper part. The upper part of the pylon includes a rotary inertial mass, giving gyroscopic stabilization to the top of the pylon. At least a part of the upper pylon structure includes a deformable parallelepiped linkage, arranged so that the spars on which the aerials are mounted remain parallel to the ground, even when the overall structure of the pylon flexes. The parallelepiped linkage may be sustained by at least two tensioned cables.

Description

The present invention relates to the field of radio broadcasting equipment.

Such equipment is deployed in the field for teletransmissions, both at the telecommunications level such as the antennas intended for the GSM system (in English Global System for Mobile Communications) and PCS (Personal Communications Services), and more generally for radio relay stations, other present or future technologies, which would require air links.

In the state of the art, various mast and pylon solutions intended for television broadcasting are known.

Telescopic masts are known in particular, the essential merit of which is to allow a structure to gradually become lighter in height while retaining optimum resistance to the wind.

For example, French patent FR2745423 describes an antenna support comprising two parallel fasteners articulated close to each other by one end at the base of a rigid support, and fixed to a vertical to form a deformable quadrilateral in the vertical plane to adjust the tilt of the antenna.

PCT patent W09858420 relates to a cell site assembly, which is integrated with different antennas and components so that the assembly is easy to install on a cell site without the need for extensive wiring or the like. The set also includes a light fiberglass housing, which surrounds the antenna without disturbing its operation. The assembly has a balancing system intended to raise or lower the housing so as to access the antenna. PCT patent W09966589 describes an antenna configuration intended to be used in particular with a cell phone system and in a rural environment. This antenna device comprises a hollow steel support column covered with a hollow sheath made of plastic reinforced with glass fibers, for example. The support column and the sheath are designed so as to have an external appearance simulating the bark of a tree, such as a Scots pine. The column is bolted to a concrete base placed below ground level, and has a cover simulating the roots of the tree. The sheath carries and contains a omnidirectional antenna connected to a feed line passing through the column and through a pipe located inside the concrete base. The equipment compartment of a cell phone system base station is connected to the antenna power line.

European patent EP106069 having the title telescopic mast intended to support the antenna provides for the pneumatic adjustment of the telescopic tubes, the advantage of which is the very rapid assembly on site, and the high compactness.

European patent EP57002 having for title "Telescopic antenna mast" describes a device whose interest is only to put forward a telescopic system for lifting devices to high heights.

In these support systems, the greatest rigidity is generally sought so as to maintain the most perfect pointing, a characteristic which is all the more important the higher the frequency of the transmissions and the greater the distance from the supports. Indeed, an increase in the frequency means a greater directivity of the radiations (propagation tending towards an "optical" behavior) and consequently the requirement of a greater precision in the transmission. In the absence of this precision, the communications coverage is imperfect, the network possibly even being faulty.

The consequence is that a high rigidity of the supports usually results in a more robust constitution, and consequently in the use of more better materials.

To offset the costs entailed by the need to have larger and heavier pylons, it is currently the practice, particularly in the present case, typically for support pylons for GSM, to use a trellis system , therefore made up of portions of metal profiles riveted and welded together. The calculations for this metal construction start from a specification which notably specifies weather resistance, including deformations in the wind, so as to guarantee the functioning of the network and transmission coverage.

As an indication, for the GSM, the value of the depointing should not exceed i or even 20 ', in case of strong wind.

The current generalization of the mobile telephone system and of the services which are and will continue to be associated with it (access to databases and to the Internet, for example) mean that the requirements for antenna support towers are becoming greater, but simultaneously arise the problems of material and manufacturing costs of these supports, of preparation times, as well as that of their transport, their mounting and their installation. In urban areas in particular, in order to provide users with perfect coverage, installers are required to install their antennas on the roofs of the tallest buildings, this poses many problems of fixing, when we know the current supports, made of the required rigidity, require a significant guying.

Finally, from an environmental standpoint, the current proliferation of GSM pylons of a certain volume is likely to disfigure the landscape.

 The state of the art in terms of antenna support pylons reveals, in addition to the wish to lighten these systems, other fundamental needs such as speed of assembly, reduction in drag, faster fastenings, immunity to vandalism (case insulated poles) The impact of a reduction in weight is reflected in the cost of raw materials, but also in the cost of transporting the equipment necessary for implementation.

In what follows, and after having mentioned these difficulties in acquiring and operating current antenna support pylons, we will endeavor to set out the advantages provided by the present invention.

We will deal more specifically below with an antenna support tower solution for the transmission of GSM signals.

The present invention therefore aims to remedy the drawbacks mentioned.

It aims to obtain a new design of antenna support pylons providing the following advantages _ Low wind drag _ Reduced weight and footprint - Preservation of antenna pointing despite controlled flexibility _ Low production cost, transport / installation and operation _ Easy assembly on site - Aesthetics The present invention thus aims at the production of an efficient antenna support pylon, at reduced acquisition and operating costs, contributing to better planning of the environment and greater convenience and quality for users.

Thus, the multiple applications that arise from these possibilities open up new perspectives in terms of standard antenna support towers.

The invention relates, in its most general sense, to a radio broadcasting device consisting of a pylon, the upper part of which supports at least one antenna connected to electronic equipment comprising an HF amplifier, characterized in that said electronic equipment is disposed in the upper part. of the pylon.

Advantageously, the electronic equipment is enclosed in a profiled housing secured to the pylon. Preferably, said electronic equipment is powered by photovoltaic cells arranged in the upper part of the device.

According to an advantageous variant, the device comprises at its upper part a rotating inertial mass producing gyroscopic stabilization.

The invention also relates to a pylon for a hertzian diffusion device according to one of the preceding claims at least characterized in that it is constituted by at least one flexible median rod having at its upper part a head disposed in a plane substantially perpendicular to said rod, said rod being provided with transverse articulated spars, the pylon further comprising non-extensible means for connecting the head, said spars and the base of the pylon to form deformable parallelepipedal modules, preserving substantially parallelism of the planes of the spars, of the head and the base. According to a variant, the connecting means consist of at least two inextensible stays arranged on either side of the rod, fixed at one end at the base of the pylon, at the other end at the head, to form a deformable parallelogram keeping the head in a substantially constant plane.

Preferably, the shrouds are integral with each of the spars, to form cells whose bases and tops are maintained in parallel planes.

According to a particular embodiment, the spars are connected to the rod by a recessed articulation along the of the rod, and free in at least one transverse direction and in pivoting with respect to at least one transverse axis.

According to a variant, the spars consist of substantially planar elements, and in that the connecting means comprise 3 guy lines.

According to a particular embodiment, the spars consist of substantially planar elements, and in this connection means a plurality of flexible rods.

Preferably, the head has a faired part which can be oriented along a vertical axis.

According to an advantageous variant, the head is mounted free to rotate and has aerodynamic drive means to create gyroscopic stabilization.

According to a preferred embodiment, the rod formed by a plurality of built-in elements. The invention also relates to a method for installing a pylon comprising a conical lower element, characterized in that the conical element is installed, which is fitted to the upper end of said conical element with a winch, and that the top element is hoisted to a height allowing the lower element to be fitted, and so on until the segment intended to be fitted into the lower element of conical shape.

As a simple non-limiting example, set out to facilitate understanding of the principles, means and methods capable of enabling the invention to be carried out, we give in diagrammatic illustration a few particular embodiments in the three attached sheets.

Figure 1 is a diagram of a conventional antenna in deformation, where we see the depointing characterized by an angle w; Figure 2 is a diagram of the deformation of a vertical parallelogram contained in a plane; Figure 3 is a profile diagram of the support pylon, according to the invention, shown in deformation; Figure 4 is a view of a stage of the tensioner or deformable star; FIG. 5 represents the monobloc upper star supporting the antennas; FIG. 6 represents a preferred articulation by cardan; Figure 7 shows another embodiment.

If we plan to make a flexible support pylon to keep the pointing of the antennas according to the invention, and more particularly according to that its application modes as well as those of the embodiments of its components to which it seems that there is instead of giving preference, the procedure is as follows or in a similar manner.

A flexible support pylon is formed in the following manner: - The central main body consists of the pylon itself, either in the form of a conventional trellis, or in tubular sections or, for smaller dimensions, in a single tube ( monotube). In our preferred option illustrated, the sections are portions of telescopic nested cones.

- At the bottom, a base - for example circular or more simply square - is either bolted to a solidly established structure, or directly embedded or buried. - At the upper part, a rigid central star with three branches, the ends of which serve as upper attachment points for the tensioners (Fig 5).

- At different intermediate levels, the three-pointed star which serves as a tensioner, consists of horizontal arms (the connecting rods) articulated, each along a horizontal axis tangent to a concentric circle with the central support. These rigid arms are made in a single piece or in a three-dimensional structure of the lattice type. The successive arms are vertically coplanar, so that only three vertical planes competing at 120 C are sufficient to contain all the planes of symmetry of the upper and intermediate branches (Fig. 3), (Fig. 4).

- In order to properly define the elementary parallelograms made up of pylon sections, connecting rods and tensioner segments, the latter are immobilized at the ends of the arms by pieces of the cable gland type through which the tensioner of circular section passes such as than a cable for example. Tightening the nut at will allows these elements to be secured.

- The articulation of the upper star in the preferential option is arranged as follows: the lower cardan link cradle is secured to the end of the support pylon and simultaneously blocks in rotation. The upper cradle, integral with the support of the reception broadcasting antennas, whatever the shape of this antenna support, and is also locked in rotation because of this, the gimbal does not rotate like a transmission element. of movement between trees. The possible movements for the gimbal are only those of pivoting around the axes of the horizontal crossbar (Fig. 5). A mechanically equivalent system is that of a ball joint whose end piece would coincide with the axis of the end of the support pylon.

- When certain pylons-supports include a shelter (called in English shelter), usually used for the apparatuses, two possibilities are offered direct installation the body of the pylon or solidly with the cage-support of antennas in such a way that this shelter can also maintain its horizontal orientation in all bending conditions.

One possibility tending to decrease drag of the assembly is that providing for the positioning of the shelter in a significantly lower position, without however being such that the apparatus can be exposed to vandalism.

- Guying: in the ferential option, the invention allows the removal of the shrouds. However, even if in certain cases it was necessary to provide shrouds - for example for reasons of insufficient security of the foundations, or desired limitation of bending - the invention makes it possible to limit its importance, and to reduce the surface covered on the ground, so the number of attachment points.

Furthermore, the attachment points to the pylon could be limited to a lower level instead of spreading over the entire height.

Behavior of the antenna support pylon with the wind: From the above, it is easy to understand that the invention, going beyond the previous need for pylon rigidity, while guaranteeing pointing in all conditions, will be best applied when the flexibility of the latter will be well known, which may result from the usual calculations of resistance of materials. The three tension cables, which will have well-defined mechanical characteristics, will be calculated so as to maintain a prestress on the body of the support pylon. In this way, any bending of the latter will allow the tensioner downwind to bring the antenna cage into a horizontal position, the other two not having the possibility of being really relaxed while exerting a permanent stabilizing effect. It goes without saying that only careful calculation makes it possible to determine the values to be given to the prestresses according to the operating conditions. Nevertheless, there is a simplicity in setting up the procedure.

With regard to the components, the invention is distinguished by the use of special elements ensuring the precision and safety of assembly and lasting operation - light, robust arms, fitted with cable glands - frustoconical portions of which we we propose to define the relationships as well as the specific fixing modes.

- wear-free joints lubricated for life It offers the possibility, compared to integral trellis systems, of placing the conductive cables inside the tubes sheltered from the weather.

elsewhere, the procedures for obtaining and using this set are themselves subject to several transpositions, particularly depending on the general dimensions, location, and foreseeable climatic conditions.

Thus, for support pylons of current dimensions close to twenty meters, a simple central body design is that of two or three superposed sections bolted to each other by means of external flanges. Even more simply, a one-piece body can be designed when transport conditions are not an unfavorable or unacceptable factor.

It should also be noted that the preferred arrangement of the invention allowing the internal passage of the cables increases the shielding of the latter.

The invention is naturally conceivable in several variants, depending in particular on the materials, environmental conditions, aesthetics, etc.

probably advantageous design allowed by the invention is that already mentioned consisting of central body arranged in several telescopic frustoconical sections including a particularly simple and interesting arrangement that consisting of a robust assembly by flanges or, for a given junction: flange attached to the outside the lower part of the upper section, and attached flange inside the lower tube in the upper part.

Another variant concerns a device having a lower lattice part, surmounted by a frusto-conical upper part made of an envelope such as a tube.

At the level of the upper star, two devices can also be applied to ensure free articulation: the first consists of an articulated cone, a kind of planar ring arranged on concurrent inclined feet, and the second in a similar elastic ball joint in its form certain joysticks "in English.

Figure 6 shows an alternative embodiment. The device comprises a supporting rod having a lower section (100) formed by a conical wire mesh extended by a plurality of section (101 to 104) nested one inside the other. rod supports at its upper end a head (105) articulated in pivoting and transverse displacement.

shrouds (110, 111) ensure the parallelism of the head (105 with the base of the device, and the maintenance of the head in a substantially constant plane, even when the rod bends under the action of the wind.

spars (120 to 123) are articulated with respect to the stem and form with the shrouds deformable cells, retaining the parallelism of the spars.

The upper part has several platforms (130, 131) held parallel by the shrouds (110, 111) and articulated in pivoting and transverse displacement like the spars. These platforms allow the antennas (132) to be placed.

The rod also supports a housing (140) containing the electronic equipment. This avoids line losses caused by the cables connecting the antennas to the electronic equipment usually placed at the base of the pylon.

This case has a double skin to improve heat exchange.

The assembly is done by first installing the conical lattice structure (100).

A winch is then installed at the upper end of this structure (100).

The upper section (103) equipped with the head is then hoisted, using the winch, until its base reaches a height allowing it to fit into the lower section (102). This operation is repeated by hoisting the newly introduced section with the winch to place the next section, and so on until the rod is raised.

 The shrouds are fixed on the head at the start of the operation, and serve as a shroud in the provisional phase and are then subjected to a slight constraint to balance the rod.

Claims (1)

CLAIMS - Over-the-air broadcasting device consisting of a pylon, the upper part of which supports at least one antenna connected to electronic equipment comprising an HF amplifier, characterized in that said electronic equipment is placed in the upper part of the pylon. - Radio broadcasting device according to claim 1 characterized in that said electronic equipment is enclosed in a housing [shelter] profiled integral pylon. - Wireless broadcasting device according to claim 2 characterized in that said electronic equipment is powered by photovoltaic cells arranged in the upper part of the device. 4 - Hertzian broadcasting device according to any one of the preceding claims, characterized in that it comprises at its upper part a rotating inertial mass producing gyroscopic stabilization. - Pylon for a radio broadcasting device according to one of the preceding claims at least characterized in that it consists of at least one flexible central rod having at its upper part a head disposed in a plane substantially perpendicular to said rod said rod being provided with articulated transverse spars, pylon further comprising non-extensible means for connecting the head, said spars and the base of the pylon to form deformable parallelepipedal modules, substantially preserving the parallelism of the planes of the spars, the head and the base . 6 - Pylon according to claim 5 characterized in that the connecting means are constituted by at least two inextensible stays arranged on either side of the rod, fixed at 'one of the ends at the base of the pylon, at 1 other end to the head, to form a deformable parallelogram keeping the head in a substantially constant plane. 7 - Pylon according to claim 5 characterized in that guy lines are integral with each of the spars to form cells whose bases and vertices are maintained in parallel planes. 8 - Pylon according to claim 5, 6 or 7 characterized in that the spars are connected to the rod a recessed joint along the axis of the rod, and free in at least one transverse direction and pivoting relative to at least one transverse axis. 9 - Pylon according to any one of the preceding claims 5 to 8 characterized in that the spars are constituted by substantially planar elements, and in that the connecting means comprise 3 guy lines. 10 - Pylon according to any one of the preceding claims 5 to 8 characterized in that the spars consist of substantially planar elements, and in this connection means a plurality of flexible rods 11 - Pylon according to any one of the claims previous 5 to 10 characterized in that the head has a faired part which can be oriented along a vertical axis. 12 - Pylon according to any one of the preceding claims 5 to 11 characterized in that the head is mounted free in rotation and has aerodynamic drive means to create gyroscopic stabilization. 13 Pylon according to any one of the preceding claims 5 to 12 characterized in that the rod is formed by a plurality of built-in elements. 14 - Pylon according to claim 13 characterized in that the lower element is of conical shape. 15 - Method for installing a pylon according to claim 14 characterized in that one installs the conical element, that one equips the upper end of said conical element with a winch, and that one hoists the crown element to a height allowing the lower element to be fitted, and so on to the segment intended to be fitted into the lower conical element.