GB2044221A - Arrangement for maintenance of equipment at the top of a tower - Google Patents

Abstract

An assembly (1) for fixing equipment to the top of a high tower (2) comprises an equipment supporting annular platform element (4) slidably guided along the outside surface of the tower (2). To the platform element (4) are secured the ends of three suspension cables (11), the other ends whereof carry a counterweight (6) which is caused to rise and lower inside the tower (2), a hook element (16) being provided for hooking the counterweight (6) to the base of the tower (2). <IMAGE>

Description

SPECIFICATION An assembly for fixing an apparatus to the top of a tubular tower of great height This invention relates to an assembly for fixing an apparatus to the top of a tubular tower of great height.

In the field of floodlight, metheorological, and the like instrument installation at great heights, the systems currently employed reveal some shortcomings as relates to cost and assembling procedure, and even more so, as relates to the difficulties encountered in routine maintenance and servicing of the installed apparata; the personnel in charge of such operations being usually compelled to reach the top of a tower either by means of aerial ladders or of a ladder incorporated to the tower itself.

This invention sets outto obviate the cited shortcomings by providing an assembly which affords the possibility of carrying out in a most safe and quick manner--also under the profile of job security -maintenance operations connected with apparata installed on great height towers.

Within that general aim, it is possible to arrange that the above object is achieved by means of a simple structure which is comparatively easy to manufacture, reliable and effective in operation, and relatively economical.

According to one aspect of the present invention, there is provided an assembly for fixing an apparatus to the top of a tubular tower of great height, characterized in that it comprises: an annular platform to which the apparatus is mounted, said platform being slidably guided along the exterior of the tower, and to which are secured the ends of at least three suspension cables, the other ends of said cables being attached to a counterweight arranged to slide inside the tower; a head anchored to the tower top and carrying, evenly spaced apart thereon, small wheels for said cables having horizontal axes; means for hooking said counterweight to the base of said tower; latch blocking means for said platform at the tower top; and means for raising and lowering said counterweight.

Further features will be more clearly apparent from the following detailed description of a preferred but not restrictive embodiment of an assembly according to this invention, illustrated byway of example only in the accompanying drawings, where: Figure 1 is a side view, partly cut away, of a tower equipped with the assembly according to this invention; Figure 2 is an enlarged side view of the base of the tower of Figure 1; Figure 3 is an enlarged side view of the top of the tower shown in Figure 1; and Figure 4 is a detail view of Figure 2, to an enlarged scale.

With reference to the drawing figures, there is generally indicated at 1 the assembly of this invention for fitting or attaching apparatus to the top of a tubular tower 2.

The tubular tower 2, of great height, advantageously results from several elements 2a, 2b, 2c, having at their ends respective flanges 3 secured to each other by means of bolts. The assembly 1 comprises an annular platform or ring 4, a head 5 and a counterweight 6. The ring 4 is constructed of mutually welded and bolted sectional members such as to define a central area A which is guided along the exterior of the tower; to the platform 4, there are attached the apparatus to be lifted up, which may be, for example, floodlights and ancillary equipment, such as transformers or the like.

The head 5 is made up of a tubular cap 7 which is fixed by means of bolts to the tower top; to the cap 7, there are welded three boxes 8 of inverted "U" cross-sectional configuration which project at right angles to the axis of the cap 7 and are offset from one another, in plan view, by 120"C; close to the cap 7, between the flanges of the boxes 8, there are mounted respective small idle wheels 9, whilst remotely from the cap, between the box flanges, there are mounted respective small idle wheels 10: around the wheels 9 and 10, which are formed with a su bstantia ly semi-circular cross-section groove, of each box a related cable 11 is passed which is anchored with one end to the ring 4, cable tensioning means 12 being respectively provided which are adapted for adjusting the length of the three cables.

The cables 11 are attached, at their free ends, to the counterweight 6, which counterweight carries an eye 13 at the bottom thereof.

To the base and inside the element 2a, there is affixed a cross-member 14to which a tensioner 15 is articulated which is provided with hook 16 for anchoring to the eye 13: the crossmember 14 carries an idle mounted grooved wheel 17, and through the element 2a, an access opening 18 is cut which can be closed by means of a respective door; above the opening 18, through the element 2a, a further opening 19 is formed of larger size and also shut by means of a respective door.

For lowering and raising the ring, there is provided a hand-operated carriage 20 comprising two beams 21, extending substantially parallel to each other and held apart from each other by welded crossmembers which carry two coaxial idle wheels 22, the ends of the beams being provided with respective handles 23 for moving the carriage: the carriage can take the stable configuration shown in Figure 2, in which case the bottom ends of the beam will rest on the ground, or be tilted with the beams 21 forming an acute angle with the ground surface in order to move it away.

To the beams 21, there are attached perpendicularly arranged sectional members 24,25,26, which define a rigid bearing frame for a motor-reducer unit 27 and a magazine 28 for a chain 29; the chain 29 terminates with a hook 30 adapted for insertion through the eye 13 in the counterweight, and the unit 27 comprises a friction clutch coupling which acts as an end-of-travel safety device to protect the unit from overloads.

The carriage can be connected to a power supply box 31 located at the base of the tower, and a remote control 32 may be provided for the motor 27: to the power supply box 31 are led the electric terminals of a power supply cable for the apparatus carried on the ring 4, that cable ending on the counterweight 6 and running around respective wheels carried idly on the head 5 in a similar manner two the cables 11.

For centering and securing the carriage to the tower, a hook like element 33 is provided which isaffixed to the sectional member 25 and faces downwards, it being adapted for insertion from above, bayonet-fashion, into a "U" shaped bracket 34 which is welded to the tower: to the sectional members 26, arranged above the extruded sectional members 25, there is attached a flat strip 35 perforated with holes for allowing bolts 36 therethrough: to the tower, there are welded nuts 37 into which bolts 36 can be threadably engaged for firmly securing the carriage to the tower.Between the ring 4 and cap 7, there are arranged latch blocking means 38 comprising at least three elastically deformable leaves 39 which are attached, offset by 1200 in plan view, to the ring 4 by means of bolted gussetts 40; at their top ends, the leaves 39 carry respective rollers 41; to the cap, there are respectively attached three cam assemblies 42 comprising two straight sectional members 43a, 43b each, which are arranged substantially V-like and inclined such that, as the ring 4 is being raised, the roller 41 is enabled to occupy (black arrows) in succession the positions shown in dotted lines in the figure (41 a, 41b, 41c) and in particular enabled to move from a released position 41a to a position 41b where the roller 41 is blocked to the cam 42 and the ledge cannot move down: to lower the ledge, it will be necessary to raise the ring for a short distance until the roller disengages from the cam to take the configuration 41c, in which position, as the ring is lowered, the roller is able to rolling along the outside face of the sectional member 43a to disengage itself.

Advantageously, to the platform or ring 4, there is mounted a microswitch 44 which cooperates with a respective feeler 45 associated with the cap 7 and to which the motor 27 is interlocked, such as to cause the motorto stop upon the roller 41 reaching its configuration in engagement with the cam 42.

The assembly of this invention operates as follows.

When it becomes necessary to carry out maintenance operations on the apparatus located at the tower top, the carriage is secured to the tower after opening the doors of the openings 18-19. The chain 11 is passed around the pulley 17 as shown in Figure 2, and the hook 30 is hooked to the eye 13: the carriage cable is connected to the socket 31 after the apparatus supply cable has been removed from the socket: the tensioner 15 is released and then the motor-reducer unit 27 is operated such that the chain is first wound in the direction to lower the counterweight, in order to disengage the roller 41 from the cam 42, thereafter it is unwound in the direction of the arrow B until the apparatus on the tower outside reach a level where they are easily accessible.

After completing the maintenance operations required, the above procedure is followed in the order to raise the apparatus back to the tower top: as mentioned in the foregoing, the motor 27 is interlocked to the microswitch 44 which ensures the stopping of the motor as the roller reaches its engaged configuration (41b): at this point, the hook 16 of the tensioner 15 acting as a safety device is again hooked.

Advantageously, the controls 32 are low voltage ones and the materials employed are suitably treated to provide long life for the assembly even if operated in adverse environmental conditions.

Thus, it will be appreciated that the invention achieves its objects, and in particular affords the possibility of carrying out, easily and under extremely safe conditions, any maintenance or servicing operations required by apparatus placed at the top of great height tubular towers.

The invention as described is susceptible to many modifications and variations, all of which are intended to fall within the scope of the instant inventive concept.

Moreover, all of the details of can be replaced by other technically equivalent ones.

In practicing the invention, the materials used, as well as the shapes and dimensions, may be any ones to suit individual requirements, without departing from the true scope of the appended claims.

Claims (9)

1. An assembly for fitting an apparatus to the top of a tubular tower of great height, characterized in that it comprises: an annular platform to which the apparatus is mounted, said platform being slidably guided along the exterior of the tower, and to which are secured the ends of at least three suspension cables, the other ends of said cables being attached to a counter-weight arranged to slide inside the tower; a head anchored to the tower top and carrying evenly spaced apart thereon, small wheels for said cables having horizontal axes; means for hooking said counterweight to the base of said tower; latch blocking means for said platform at the towertop; and means for raising and lowering said counterweight.

2. An assembly according to Claim 1, characterized in that said head comprises a tubular cap screw fastened to the tower top, said tubular cap carrying fixed radially thereto three downward facing boxes idly supporting said wheels, there being two such wheels per box.

3. An assembly according to Claim 2, characterized in that said cap carries a box and a wheel with additional wheel hub for passing a power supply cable for electrical apparatus, said cable being anchored with its ends to a terminal board rigid with the platform and to a terminal board rigid with the counterweight.

4. An assembly according to Claim 1, characterized in that said means for hooking counterweight comprise a tensioner adapted for being hooked to said counterweight as the latter is in its lowermost position.

5. An assembly according to Claim 1, characterized in that said means for raising and lowering the counterweight comprise a chain adapted for being hooked to the counterweight and a pulley idle mounted to the tower bottom at the location of a door for loading said chain out horizontally.

6. An assembly according to Claim 5, characterized in that externally to said tower a carriage can be anchored, said carriage carrying a motor-reducer unitfordriving said chain.

7. An assembly according to Claim 1, characterized in that said latch blocking means for the platform at the tower top comprise several elastically deformable leaves, said leaves being affixed downwardly to the platform and upwardly carrying respective rollers adapted for abutting against respective cams fixed to the head and being arranged with a V-like inclination.

8. An assembly for fitting an apparatus to the top of a tubular tower of great height, substantially as herein described with reference to the accompanying drawings.

9. Any novel element, or combination of elements, herein described and/or shown in the accompanying drawings, irrespective of whether the present claim is within the scope of, or relates to the same invention as, any of the preceding claims.