EP1617015A2 - Metal mast and its construction method - Google Patents

Abstract

The mast comprises a pole body (4) that is connected to a strap (10) at one end. A pole body (6) has a polygonal base and is connected to a base plate (8) at another end and to the strap at the former end. The pole body (6) has a transversal encumbrance strictly lesser than a transversal space defined by the pole body (4) such that a gap (11) separates the body (4) from the body (6) along their circumference. An independent claim is also included for a method for manufacturing a mast.

Description

The invention relates to a metal mast, in particular for making a pole, and a method of manufacturing such a mast.

Large metal poles are conventionally used to form poles, for example street lighting poles or poles that support electrical cables for the transport and / or distribution of electricity, as is the case for the use of poles. supply of trams.

The large size of the mast and the significant forces that are generated at the top of it imply the use of a substantial thickness of metal, which can be of the order of 20 to 50 mm or more, if one realize the mast by means of a single drum.

The use of sheets of such a thickness for the production of masts is problematic for several reasons: firstly, the obtaining of rounded shapes, particularly sought after for the aesthetic aspect that they confer on the mast, is not not possible by folding sheets of this thickness with conventional means and an affordable price; on the other hand, the longitudinal welding of such sheets is difficult.

For these reasons, metal poles are conventionally produced which require a substantial thickness of metal in cast iron. The use of such a technique is however expensive and the masts thus obtained are particularly heavy.

In order to circumvent these problems, it has been proposed to produce the mast by assembling several concentric barrels, identical in their general shape and crimped into each other, with the idea of reproducing by assembling the different barrels. the thickness of metal made necessary by the dimensioning of the mast. Thus, each barrel has a reduced thickness relative to the thickness required for the entire mast and can be made to the desired shape with conventional and less expensive means. The solution described in document US 3,040,846 is similar to this type of mast.

However, because of the crimping of the different drums one into the other, most of the metal surfaces involved are in contact with other metal surfaces, so that they are not properly protected during the step of galvanizing. Poles made using this technique are therefore particularly prone to corrosion.

In this context, the invention aims to provide a metal mast design that allows it to achieve it with freedom in its form, in a practical and inexpensive process that provides good protection against corrosion to all surfaces metal of the mast.

Thus, the invention proposes a mast comprising a first shaft integral with a sole at one end and a second shaft received in the space defined by the first shaft, characterized in that the first shaft is integral with a flange. a second end and in that the second shaft is integral with the sole at one end and the flange at a second end.

This type of assembly makes it possible in particular to reduce, or even eliminate, the areas of contact between the first barrel and the second barrel. The surfaces of the drums are thus in large part accessible to the galvanizing process.

For example, it can be expected that, on at least a portion of the height of the mast, the transverse bulk of the second mast is strictly less than the transverse space defined by the first shaft so that a gap separates the first shaft the second barrel over their entire circumference. This gap allows access to the metal surfaces of the drums during the galvanizing step.

According to a possible embodiment of the sole, the latter comprises at least one recess forming access to the gap. Similarly, the flange may comprise at least one recess forming access to the gap.

In the same vein, the second barrel may comprise at least one opening forming access to the gap.

These access to the gap can further improve the galvanization of metal surfaces.

According to a first possible embodiment, the second barrel has a polygonal section, for example octagonal.

Such a shape allows the use of a relatively thick sheet (typically more than 10 mm) for the second barrel, without, however, prejudicing the aesthetic appearance of the mast since the inner barrel is not visible from the outside.

In this case, it can be provided for example that the first barrel has a wall thickness smaller than the wall thickness of the second barrel.

According to another possible embodiment, the second barrel has a circular section.

The first barrel has for example a circular section. This form is generally quite popular on the aesthetic level.

The first drum may be made of sheet metal less than 10 mm thick. For this type of thickness, various shapes can be obtained with conventional means and inexpensive.

According to one possible embodiment, an intermediate shaft is received in the outer shaft and receives the inner shaft. This distributes the efforts between the different barrels.

According to a practical embodiment, the first barrel and the second barrel are secured to the sole and the flange by welding.

• solidarisation d'un fût interne à une semelle par soudage ;
• montage d'un fût externe de manière à ce qu'il reçoive le fût interne et fixation de celui-ci sur la semelle par soudage ;
• pose d'une bride et fixation de celle-ci par soudage d'une part au fût interne et d'autre part au fût externe.

The invention also proposes a method for producing a mast, characterized in that it comprises the following steps:

• securing an internal shaft to a soleplate by welding;
• mounting an outer barrel so that it receives the inner barrel and fixing it to the soleplate by welding;
• installing a flange and fixing it by welding on the one hand to the inner shaft and on the other hand to the outer shaft.

• la figure 1 représente un mât selon un premier mode de réalisation de l'invention ;
• la figure 2 est une vue en coupe du mât de la figure 1 selon la ligne A-A de la figure 1 ;
• la figure 3 est une vue de la tête du mât de la figure 1 selon la flèche F ;
• la figure 4 est une vue de dessus du mât de la figure 1 ;
• la figure 5 représente un mât selon un second mode de réalisation de l'invention ;
• la figure 6 est une vue en coupe du mât de la figure 5 selon la ligne A-A de la figure 5 ;
• la figure 7 est une vue de dessus du mât de la figure 5 ;
• la figure 8 représente un mât selon une variante du second mode de réalisation de l'invention ;
• la figure 9 est une vue en coupe du mât de la figure 8 selon la ligne B-B.

Other features and advantages of the invention will emerge in the light of the following description given with reference to the appended drawings in which:

• Figure 1 shows a mast according to a first embodiment of the invention;
• Figure 2 is a sectional view of the mast of Figure 1 along line AA of Figure 1;
• Figure 3 is a view of the mast head of Figure 1 according to the arrow F;
• Figure 4 is a top view of the mast of Figure 1;
• FIG. 5 represents a mast according to a second embodiment of the invention;
• Figure 6 is a sectional view of the mast of Figure 5 along line AA of Figure 5;
• Figure 7 is a top view of the mast of Figure 5;
• Figure 8 shows a mast according to a variant of the second embodiment of the invention;
• Figure 9 is a sectional view of the mast of Figure 8 along the line BB.

Figure 1 shows the general appearance of a metal mast 2 according to a first embodiment of the invention.

The mast 2 mainly comprises an outer shaft 4 of frustoconical shape with a circular base (that is to say of cylindro-conical shape), an inner shaft 6 located in the space defined by the outer shaft 4 and frustoconical shape to octagonal base (that is to say octo-conical), a sole 8 located at the lower end of the barrels 4, 6 and a flange 10 located at the upper end of the barrels 4, 6.

The outer shaft 4 extends mainly along its vertical axis of symmetry. Its height along this axis is of the order of 10 to 20 times its diameter at the base, that is to say at its lower end. Moreover, the diameter of the outer shaft 4 varies little with height, so that the diameter at its upper end is of the order of half of its diameter at the lower end, and generally between 0.4 times and 0.7 times its diameter at the lower end.

As clearly visible in Figure 1, the outer surface of the outer shaft 4 essentially defines the outer shape of the mast 2 and thus the overall aesthetic appearance thereof.

The outer shaft 4 is here made by folding a steel sheet 5 mm thick.

The outer shaft 4 is fixed to the sole 8 by welding, by means of a circumferential weld 5 external to the outer shaft 4. The outer shaft 4 is also fixed to the flange 10 by welding on the outside of the outer shaft 4.

On a limited part of its height, the outer shaft 4 has an opening 12 on a small part of its circumference, for example of the order of thirty degrees. This opening 12 is generally called " door " and allows access to the interior of the mast 2 for maintenance operations on devices possibly placed inside the mast 2.

The sole 8 has the general shape of a disc of axis common with the vertical axis of the mast 2 and of diameter much greater than the diameter of the base of the outer shaft 4, of the order of twice the diameter of the outer shaft 4 .

The outer shaft 4 is welded to the sole 8 concentrically with it and thus defines in the sole 8 a ring 9 traversed by a set of cylindrical holes 7 distributed over the entire circumference of the sole 8. The holes cylindrical 7 allow the attachment of the mast to the ground, for example by means of bolts.

FIG. 2, which shows a cross section of the mast, shows in a particularly clear manner the relative disposition of the outer shaft 4 and the inner shaft 6.

The inner shaft 6 is located in the space defined by the outer shaft 4; their relative transverse dimensions leave a gap 11 between the inner shaft 6 and the outer shaft 4, ie a region 11 located outside the inner pipe 6 and inside the outer pipe 4.

Precisely, and here over the entire height of the mast, the transverse size of the second barrel is strictly smaller than the transverse space defined by the first barrel so that a gap separates the first barrel of the second barrel over their entire circumference.

This gap 11 allows the flow of acid and zinc flows during the galvanizing step and thus ensures good protection of all metal surfaces against corrosion.

The inner shaft 6 also extends mainly in the vertical direction, here over the entire height of the mast, that is to say with a height equal to that of the outer shaft 4.

As for the outer shaft 4, the inner shaft 6 is slightly frustoconical so that its bulk at its upper end is slightly smaller than its bulk at the lower end, for example in the same proportions as those mentioned above for the external shaft. 4.

Alternatively, the inner shaft 6 could be in the form of an octagonal base cylinder, that is to say with a constant octagonal section. It may be noted that this modification would have no effect on the aesthetic appearance of the mast 2 defined by the outer shaft 4 as indicated above.

The internal shaft 6 is made by assembling two half-drums 14 by means of longitudinal welds 16 clearly visible in FIG. 2. Each half-shaft 14 thus extends over the entire height of the mast 2.

The half-drums 14 (and consequently the inner drum 6 they compose) are made of 15 mm thick steel sheets by folding. Obtaining the octo-conical shape of the half-drums 14, which therefore have ridges, is easily achievable with conventional means, even for relatively large thicknesses such as the one just mentioned.

The inner shaft 6 is fixed to the sole 8 at the lower base thereof, here by means of a weld external to the inner shaft 6, and to the flange 10 at the upper end thereof, here by means an inner weld to the inner shaft 6.

The inner shaft 6 is here assembled to the sole 8 and the flange 10 by fasteners independent of those of the outer shaft 4. In the present example, there is moreover no direct link between the inner shaft 6 and the external shaft 4.

The inner shaft 6 also has an opening 18 at the right of the door 12 formed in the outer shaft 4. Reinforcing bars 20, which extend substantially along the axis of the inner shaft 6 to a height slightly greater than that of the opening 18, allow to ensure a good mechanical maintenance of the structure despite the presence of the opening 18.

The sole 8 has a central opening 13 whose diameter is inscribed in the octagonal base of the inner shaft 6 so that the sole 8 receives the base of the inner shaft 6 as mentioned above. The space inside the inner shaft 6 therefore communicates with the outside by means of the central opening 13 when the mast is assembled but not yet mounted on the ground.

The soleplate further comprises four recesses 15 regularly distributed over the circumference of the central opening 13. These recesses 15 increase locally the diameter of the central opening 13 so that it is essentially equal to that of the outer shaft 4 .

The recesses 15 thus allow communication between the central opening 13 and the gap 11 defined between the outer shaft 4 and the inner shaft 6, and hence between the gap 11 and the outside when the mast is assembled but not still mounted on the ground. This makes it possible to enter the acid and zinc streams in the gap 11 during the previously mentioned galvanizing step.

FIG. 3 shows one of two gussets 22 fixed by welding to the top of the mast 2, and, specifically, welded to the flange 10 and to the upper part of the outer shaft 4.

The gusset 22 comprises a side lug 23 provided with a through hole 24 for mounting and passing a cable.

FIG. 4, which shows the mast 2 in a view from above, clearly shows the two gussets 22.

The presence of the gussets 22 is naturally only one possible embodiment of the head of the mast 2. One could alternatively provide that the head of the mast 2 comprises a shutter (or cap), or a tube forming a rise, for example welded on the flange 10.

The flange 10 has the general shape of a ring, with an outer diameter greater than the outer diameter of the outer shaft 4 at the top and an internal diameter inscribed in the octagonal section of the inner shaft 6 at the top.

The flange 10 also forms four recesses 25 regularly distributed over its internal diameter and which locally update the inner shaft 6 and the gap 11, as clearly visible in FIG. 4.

As for the recesses 15, the recesses 25 of the flange 11 make it possible to communicate the gap 11 between the outer shaft 4 and the inner shaft 6 with the outside, in order to allow access to all the metal surfaces during the galvanizing step.

As has been seen, the use of an internal casing 6 with a polygonal base proposed in this first embodiment makes it possible to use a relatively thick sheet (typically greater than 10 mm) for the internal casing 6, this makes it possible to use a total of only two barrels 4, 6.

• fixation du fût interne 6 à la semelle 8 par soudage ;
• montage du fût externe 4 autour du fût interne 6 et fixation de celui-ci sur la semelle 8 par soudage ;
• pose de la bride 10 et fixation de celle-ci par soudage d'une part au fût interne 6 et d'autre part au fût externe 4 ; et
• montage et fixation par soudage des goussets 22 sur la tête du mât 2.

The mast 2 which has just been described can for example be assembled according to the following method:

• fixing the inner shaft 6 to the sole 8 by welding;
• mounting the outer shaft 4 around the inner shaft 6 and attaching it to the sole 8 by welding;
• installing the flange 10 and fixing it by welding on the one hand to the inner shaft 6 and on the other hand to the outer shaft 4; and
• mounting and fixing by welding of the gussets 22 on the head of the mast 2.

The entire mast 2 thus formed can then be subjected to a galvanizing process.

Figure 5 shows a mast according to a second embodiment of the invention.

The mast 100 is formed of three frustoconical drums with a circular base 102, 104, 106. In section in a plane perpendicular to their vertical axis, the drums 102, 104, 106 have concentric and disjoint circular sections, as clearly visible in the figure. 6.

The outer barrel 104 thus receives in its interior space the intermediate shaft 102, which itself receives in its interior space the inner shaft 106.

In each horizontal plane (that is to say in each plane perpendicular to the vertical axis of the mast 100), the inner diameter of the outer shaft 104 is strictly greater than the outer diameter of the intermediate shaft 102 so that a first 111 is formed on the entire periphery of the drums 102, 104. Similarly, the inside diameter of the intermediate shaft 102 is strictly greater than the outside diameter of the inner shaft 106, so that a second gap 113 is formed between the intermediate shaft 102 and the inner shaft 106.

The outer shaft 104 and the inner shaft 106 are each attached at their lower end to a sole 108 and at their upper end to a flange 110. The fasteners are here made by welding; the welds at the lower ends of each barrel 104, 106 are deposited outside thereof. The external barrel 104 is also welded to the flange 110 outside the outer barrel 104, whereas the weld that joins the inner barrel 106 to the flange 110 is formed on the inside of the inner barrel 106.

The intermediate shaft 102 is fixed by welding to the sole 108 at the lower base thereof. At the mast head 100, the intermediate barrel is for example welded to one of the other barrels.

Each barrel 102, 104, 106 is made by folding a sheet of 6 mm thick with closure by means of a longitudinal weld 120.

The mast 100 has a door 112 of the same type as the door described for the first embodiment and therefore will not be described in detail here. The door 112 is made by openings facing each other in the barrels 102, 104, 106.

The sole 108 is generally identical to the sole of the first embodiment and will therefore not be described in detail here. It may be noted, however, that the sole 108 has a central opening 114 which allows the interior space of the mast 100 to be communicated downwards when the mast 100 is assembled but not mounted on the ground. Furthermore, the central opening 114 is locally enlarged by four recesses 115 distributed over the entire circumference of the central opening 114 and which allow access to each of the first gap 111 and the second gap 113 from the central opening 114.

As for the first embodiment, it thus facilitates the access of the acid and zinc streams inside the first gap 111 and the second gap 113 during the galvanizing step, to effectively protect the assembly. metal surfaces of the three drums 102, 104, 106.

As for the first embodiment, the flange 110 is made in the form of a ring whose outer diameter allows the external barrel 104 to be fixed and whose inside diameter allows the internal barrel 106 to be fixed.

The flange 110 also comprises four recesses 116 regularly distributed on the circumference of the latter which update in particular the inner shaft 106, the second gap 113, the intermediate shaft 102 and the first gap 111. Each recess 116 thus provides access to the first gap 111 and second interstice 113 from outside the mast, as clearly visible in Figure 7. This access will be used in particular during the galvanizing step as already explained above.

As for the first embodiment, the mast has two gussets 118 mounted at the top thereof for receiving and supporting electrical cables.

Figures 8 and 9 show a variant of the second embodiment.

According to this variant, a mast 200 comprises an inner shaft 206, an intermediate shaft 202 and a frustoconical outer shaft 204 with a circular base, disjoint to each other and mounted concentrically between a sole 208 and a flange 210.

The outer shaft 204 and the inner shaft 206 in particular are attached to the sole 208 on the one hand and the flange 210 on the other hand by welding.

As clearly visible in FIG. 9, which represents the mast according to the section B-B indicated in FIG. 8, solid rods with circular sections 212 (here of diameter 5 mm) are inserted in the interstices created between the different drums.

The rods 212 are for example welded to the barrel immediately inside the gap which contains each. These rods 212 may in certain cases make it possible to improve the mechanical strength of the mast 200. However, thanks to the independent fastenings relative to each other of the outer shaft 204 and the inner shaft 206 at their two ends each, it is it is possible to provide rods 212 only over part of the height of the mast 200.

It may further be noted that, according to this variant, the intermediate barrel 202 and the inner barrel 206 each comprise openings 214 facing each other in order to allow the circulation of the acid, then zinc, during the step galvanizing, despite the presence of rods 212.

Similarly, openings 216 are formed in the inner shaft 206 and the intermediate shaft 202 facing the lower portion of the mast, as shown in FIG.

The invention is not limited to the embodiments which have just been described, which represent only examples of implementation thereof.

Claims (15)

Mast comprising a first shank (4; 104; 204) integral with a sole (8; 108; 208) at one end and a second shank (6; 106; 206) received in the space defined by the first shank ( 4; 104; 204), characterized in that the first shank (4; 104; 204) is integral with a flange (10; 110; 210) at a second end and that the second shank (6; 106; 206) is integral with the sole (8; 108; 208) at one end and the flange (10; 110; 210) at a second end. Mast according to claim 1, characterized in that , on at least a portion of the height of the mast, the transverse bulk of the second barrel (6; 106; 206) is strictly smaller than the transverse space defined by the first barrel ( 4, 104, 204) such that a gap (11; 111, 113) separates the first barrel from the second barrel over their entire circumference. Mast according to claim 2, characterized in that the sole (8; 108; 208) comprises at least one recess (15; 115) forming access to the interstice (11; 111,113). Mast according to claim 2 or 3, characterized in that the flange (10; 110; 210) has at least one recess (25; 116) forming an access to the gap (11; 111,113). Mast according to one of claims 2 to 4, characterized in that the second barrel (6; 106; 206) has at least one opening (214, 216) forming access to the interstice. Mast according to one of claims 1 to 5, characterized in that the second shaft (6) has a polygonal section. Mast according to claim 6, characterized in that the first barrel (4) has a wall thickness smaller than the wall thickness of the second barrel (6). Mast according to claim 6, characterized in that the second barrel (6) is made of a sheet thicker than 10 mm. Mast according to one of claims 1 to 5, characterized in that the second barrel (106; 206) has a circular section. Mast according to one of claims 1 to 9, characterized in that the first shaft (4; 104; 204) has a circular section. Mast according to one of claims 1 to 10, characterized in that the first shank (4; 104; 204) is made of sheet metal less than 10 mm thick. Mast according to one of claims 1 to 11, characterized in that an intermediate shaft (102; 202) is received in the outer shaft (104; 204) and receives the inner shaft (106; 206). Mast according to one of claims 1 to 12, characterized in that the first shank (4; 104; 204) is secured to the sole (8; 108; 208) and to the flange (10; 110; 210) by welding. . Mast according to one of claims 1 to 13, characterized in that the second shank (6; 106; 206) is secured to the sole (8; 108; 208) and to the flange (10; 110; 210) by welding. . Method for producing a mast, characterized in that it comprises the following steps: - Securing an inner shaft (6; 106; 206) to the sole (8; 108; 208) by welding; - mounting an outer shaft (4; 104; 204) so that the outer shaft (4; 104; 204) receives the inner shaft (6; 106; 206) and secures the outer shaft (4; 104; 204) on the sole (8; 108; 208) by welding; - Securing a flange (10; 110; 210) by welding to the inner shaft (6; 106; 206) and the outer shaft (4; 104; 204).

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