The invention concerns an extending barrier on wheels consisting of various swiveling modular elements, deployable and folding manually.
 In a prior embodiment, there is already a barrier forming extending diamond shapes on a guide cable for roads, whether urban or pedestrian, described in document FR 2 688 244. This former embodiment has the following drawbacks: it is made of corrosion-proof steel and is accordingly very heavy to manipulate. It is operated by a guide cable stretched between two fixed points by at least one cable, to which it is immobilized; this cable is pulled by a mechanical manual, semi-automatic or automatic winch arrangement There is no detail given of the mechanism for its deployment, but only for folding, except in FIG. 5 presenting a cable-operated system that is not described with a return loop in a guide rail for fixed installations. To open the passage, it must be pulled with a cable puller. No mention is made that the cable or cables preventing access have to be removed when the barrier is folded impede the passage of pedestrians or vehicles, and how they are removed to very quickly liberate access. Similarly, to close the access, mention is made of a cable puller that is not illustrated. The cables have to be put back in place manually and tensioned before the barrier is extended. The barrier is immobilized not between fixed points but on a cable at either end by cable grips. It is necessary to loosen the cable grips on the winch side to be able to fold the barrier. These facilities are complicated, very costly and slow to work. Because the barrier is used outdoors, in different kinds of weather, it is exposed to impacts, each of which will represent a rust spot. It includes dangerous protruding angles for the pedestrians it is designed to channel. It does not include any means of adaptation to allow for passages over sidewalk or irregularity in the surface of the sites where it is to be deployed and remains suspended from its cable. It does not include any deployment limit safety arrangement, left to the initiative of the person installing it with cable pullers. The barrier is heavy, complicated and requires particularly costly facilities to set it up, deploy, fold and transport it, for provisional installations.
 The problems to be resolved to construct a light, deployable and quickly folding barrier, operated manually and easy to transport and implement on the sites of use, are as follows:
 to be able to construct a light but rugged barrier that can be extended and folded manually and quickly, preferably by one person;
 to be able to positively limit its deployment to prevent it from being extended beyond its correct lateral stability limit;
 to be able to improve its lateral stability and above all its resistance to tipping, in particular for greater lengths;
 to be able to preserve good floor bearing over the entire length, even on irregular surfaces (sidewalks) to preserve lateral stability without causing it to twist;
 to be able to lock its fixed points at either to prevent anybody from opening it without authorization;
 to be able to resist corrosion, even in the event of impact in the course of manipulation;
 to avoid any dangerous protruding angles for persons moving nearby;
 to be able to render the barrier visible at night, even in the event of a power failure.
 All these problems are resolved with the extending barrier wheels according to the invention, consisting of modular sections pivoting between one another of light alloy, anti-corrosion treated, all identical and each comprising two vertical X-shaped arms swiveling on a pin at the center and at the ends on the following element, rendering it extendible and folding manually; the end elements of the barrier are each provided with attaching means, preferably locking, each to a corresponding fixed point for immobilization in the extended position between said fixed points integral with the site or added in the form of metal posts anchored provisionally or definitively to it.
 The two ends of the barrier may each be terminated by a complete X-shaped modular element, these ends having each either two or four means of attachment in the extended position to a corresponding fixed point on the site, with said attachments working together as a limiter for the deployment of the battery, and acting as side stabilizers.
 The two ends, as an alternative, each terminate with a special modular element consisting of a normal V-shaped half-element swiveling as a triangle, provided at the swiveling end with at least one means of attachment to the corresponding fixed point of the site.
 The means of limiting deployment between two attaching points on the site comprises at least one chain tensioned between two successive modular elements, or yet again by two identical connecting rods articulated between one another and between two central pivots comprising two successive X-shaped modular elements. Each of these wheels is attached to the end of a pin sliding in a tube integral with the corresponding modular element, comprising a high stop defining the normal retracted position of each wheel, while the low position, variable according to the difference in level of the site, is maintained by a self-locking means on the pin support, both in the low and in the high position, so that the barrier can be extended over the entire length over an unequal ground surface.
 For long barriers requiring greater lateral stability, the stability is reinforced by an assembly of modular elements comprising two vertical arms forming an X, swiveling at the center in which the two arms on the same side are extended one step beyond the end of the normal module arms, which extended arms have a fourth pivot at the end, extending for their attachment to the following identical module or to a special end module. When formed by an assembly of modular elements with reinforced lateral stability, the special end modules include an arm of the normal modular element working together with an arm of the special modular element so that the arms of this special modular element terminate in the same vertical plane perpendicular to the longitudinal axis of said barrier, while the free end of the normal module arm pivoting on a short arm, also pivoting at the end of the extended arm of the previous modular element, said ends each being provided with means of attachment with or without a lock in the fixed part of the site, for immobilizing said barrier.
 As an alternative, its two special end modules comprising two arms of the normal modular element, working together with a special module arm and a short arm having the length of one pitch step, forms an end triangle provided with a means of attachment to a fixed point of the site, while the other end of said reinforced barrier may be symmetrical or identical to the other.
 The main arm of the modular elements includes a U-shaped profile provided with means of clipping on a handrail profile. The bars are fixed between two portions of this profile, which includes holes for the passage of pivot rods attached to them.
 The secondary arms of the modular elements consist of two portions of a U-shape profile comprising means of clipping a cover in place. This profile is pierced with bar attaching holes and at the articulations, has a punched hole for the passage of a bar through which the pivot pin passes.
 The bars are rectangular in section with rounded angles, and the middle of the lower face of the two smaller sides includes an attachment screw recess, consisting of four screws between the profiles of the main and secondary arms.
 The pivoting of the secondary arms of the modular elements between the main arm profiles provided with their bars is through a pin engaged in the corresponding holes of said profiles, nuts locking it to the two profiles of the main bar, leaving a slight play to allow the secondary arm to pivot easily.
 The ends of the secondary arms have a retracting plate system bearing on the ground comprising a means of rapid locking in the idle position or bearing on the ground. The barriers are obtained by assembling as many normal or special X-shaped modular elements as necessary with their end elements, including their means of attachment that may be locked by a padlock or a lock.
 Transport and provisional installation on site, when long lengths are needed, is carried out using several folded sections easily loaded onto a truck with a forklift truck. The sections are assembled together by interconnection plates made integral with the main arm profile closing parts, extended on the outside by a plate drilled with a large hole in which a shouldered pin is engaged, locked by the hasp of a padlock.
 The locking of the end closing parts to the corresponding fixed points of the site is by a clevis in which a shouldered pin is engaged and locked with a padlock. The clevis is extended by a threaded pin inserted in one hole of a metal plate and locked by means of four nuts after the interposition on either side of a conical washer plate damping the forces bearing on the barrier.
 The advantages of the barrier according to the invention are as follows:
 a particularly light barrier, meaning easy handling by a single person because the pivoting of the arms takes place smoothly on the bearings;
 self-limiting of the deployment to maintain lateral stability;
 good lateral stability, even for considerable lengths in one piece;
 good bearing on the ground over the entire length, even at curb crossings, thanks to a system of self-locking sliding support plates;
 its construction, preferably of anodized light alloy, lacquered or other, allowing its use under all-weather conditions without any risk of rusting;
 absence of protruding angles to avoid any risks of accidents to passers-by;
 the possibility of locking the barrier at both ends at fixed points by a padlock or a lock;
 the assembly of barrier modules with wide bars using four screws giving it good longitudinal strength.
 The main uses of the barrier according to the invention are as follows: access prohibition, filtering of pedestrian entry to a site; separation of zones from one another; isolation of objects, locations or machines; guidance, channeling of people, animals, vehicles, etc.
 The invention is described in detail in the following text with respect to the attached illustration given on a non-limitative basis, in which the following are illustrated:
 FIGS. 1 and 2, perspective and top view of an example of modular elements forming an extending barrier according to the invention including, on one side, double attachment to the site and on the other, a single attachment;
 FIGS. 3 and 4, schematic top view of an alternative barrier consisting of modular elements with a single attachment at either end;
 FIG. 5, an example of a chain limiting the deployment of the barrier in FIGS. 3 and 4;
 FIGS. 6 and 7, schematic top view of an alternative barrier consisting of modular elements with two attachments on one side and one attachment at the other end;
 FIGS. 8 and 9, schematic top view of an alternative barrier consisting of modular elements with two attachments at either end to the fixed points of the site;
 FIGS. 10 and 11, perspective and top view of an example of modular elements forming at extending barrier reinforced laterally according to the invention, including on either side a simple attachment between two fixed points on the site;
 FIGS. 12 and 13, top view showing an example of modular elements forming an extending barrier reinforced laterally according to the invention, comprising on either side a double attachment between two fixed points on the site;
 FIGS. 14 and 15, top view showing an example of a variant of modular elements forming an extending barrier reinforced laterally according to the invention, and including a single attachment between two fixed points on the site at either end;
 FIGS. 16 to 21, examples of profiles for the construction of central or end pivots of the barrier according to the invention;
 FIG. 22, an example shown in section of a barrier pivot;
 FIG. 23, an example of the assembly of a bar on two arms of the modular elements;
 FIG. 24, a sectional view, example of a ground bearing plate mounted at each outer articulation of the barrier;
 FIG. 25, a schematic top view of a long barrier according to the invention, consisting of several sections to be assembled on site;
 FIG. 26, a schematic side elevation view of the attachment of two barrier sections together;
 FIG. 27, an elevation view example of a barrier end attachment to a post provisionally or otherwise anchored on the site of use;
 FIG. 28 a perspective view showing details of the pivoting of the main and secondary arms of barrier modular elements according to the invention.
 FIGS. 1 and 2 give a perspective and top view of examples of various modular elements 1 articulated in 2's to form an X so that when assembled, they form an extending barrier according to the invention of any length, as required by users. Details of the method of construction are given in FIGS. 16 to 22. On one side, in module 1A, it includes two identical means 3, 4 of attachment on site, equipped with complementary locking resources. Special end module 5, triangular in shape forming a V swiveling at 6, includes a single means of attachment 7 to the site, identical to means 3, 4. If increased stability of the barrier is desired, giving it high anti-tipping resistance, it is possible to add a lower means 8 identical to the others 3, 4, 7. FIG. 27 shows a preferential mode of attaching the end modules on site. Each modular element has two swiveling wheels 10, 11, arranged in opposition at the bottom , so as to provide for each extension and folding of the barrier. At the top, each modular element has a handrail 12. Each modular element, single or reinforced, as well as special modular end elements, are made of two arms 14 and 15 of different heights, while secondary arm 15 swivels within main arm 14. Arm 14 has two profiles 16 between which are attached profiles 17, known as bars. Profile 12 of the handrail clips onto profile 16. Bars 18 of arm 15 are shorter than bars 17 or arm 14. Arm 15 consists of two identical profiles 20, between which bars 18 are attached by swaging. Details of swiveling ends 6 can be seen in FIGS. 22 and 28.
 FIG. 3 and 4 are schematic top views of an alternative barrier consisting of modular elements 1 swiveling in an X, and special modular elements 5 for the ends with a Vee pivot and one attachment 4, 7, working together with complementary resources on the site. FIG. 3 shows modular elements 1 separated before assembly, terminated by two V-shaped elements 5, assembled as in FIG. 4. Chain 22 of FIG. 5 is designed to limit the extension of the terminal barriers by two special V-shaped modular elements.
 FIGS. 6 and 7 are schematic top views of an alternative barrier consisting of modular elements 1 with two attachments 3, 4 on one side of element 1A and a single attachment 7 to V-shaped element 5 at the other end. Attachments 3, 4 of element 1A ensure self-limiting of barrier deployment even if, at the other end, it terminates in a V-shaped modular element 5.
 FIGS. 8 and 9 are a schematic top view of an alternative barrier consisting of modular elements 1 swiveling in an X, not assembled, whose end elements 1A comprise at least two attachments 3, 4 at either end to the fixed points of the site. FIG. 9 shows modular elements assembled and held between fixed points of the site S1, S2.
 FIGS. 10 and 11 are a perspective and top view showing an example of identical separate modular elements 25 forming an extending barrier and reinforced laterally according to the invention, including on either side a special V-shaped modular element 26 on the left and 27 on the right, each provided at the point of articulation with attaching means 4, 7, between two fixed points of the site S1 and S2. These reinforced modular element each include a section or arm extending by one pitch step 29 on the same side and terminating with a fourth pivot. Left-hand end modular element 26, V-shaped, has a two-pitch step arm 30 (where the pitch is the distance between two pivots of the same arm, and all the pitches being identical for the same barrier) and an arm 31 of a single-pitch step swiveling between one another, while arm 31 includes a means of attachment 4 on site S1. The following modular element 28 is special, including a normal arm 33 for three-pitch steps and a second arm 34 with two-pitch steps, while the pilot 35 is X-shaped and situated on the first step. These reinforced modular elements are built, to within an additional pitch step, in the same way as the modular elements of the non-reinforced barriers. Modular element 27 of the second end differs from the opposite element 26 in having an additional two-pitch step arm and three pivots assembling with the normal following element 25.
 FIGS. 12 and 13 are top views showing another example of modular elements used to construct a laterally reinforced extending barrier according to the invention, including, on either side, a double attachment 3, 4 between two fixed points on site S1 and S2, increasing its resistance to tipping. It consists of an assembly of the number of normal modular elements 25 needed to obtain the defined length of the barrier and terminating at both ends by two symmetrical modular elements 40 and 41, each comprising a normal arm with three pitch steps 33, a two-pitch step arm 30 and a single-pitch articulated arm 31 hinging on arm 30. FIG. 13 shows the various modular elements assembled together to form the barrier. In this figure, it can be seen that when ends 40, 41 of this reinforced barrier are attached at two or four points on either side to the fixed parts of the site, this barrier, even if very long, cannot be tipped over.
 FIGS. 14 and 15 show a top view giving an example of alternative normal modular elements 25 forming an extending laterally reinforced barrier according to the invention including, on either side, V-shaped end elements 26 and 27 attached between two fixed points S1, S2 of the site and the barrier assembled in this way in FIG. 15. For barriers of this type, it is preferable to have at least one module 40 or 41 at one of the ends to benefit from its anti-tipping capability, and even better, to have modular end elements with four attaching points on either side to a wall or to posts anchored on the site.
 FIGS. 16 and 17 show an example of a handrail profile 12 in an inverted U shape comprising two fins 45 acting as a stop for clipping profile 16, onto which profile 12 is designed to engage and lock by the elastic deformation of two bosses 46 clipping onto sloping parts 47 corresponding to profile 16. This profile 16 is also U-shaped, and the top section 48 of the vertical flanges is inclined to slope toward the inside so as to facilitate the engaging of clipping bosses 46 onto angles 47. Core 48 is drilled at the articulation points of the modular element arms and in its longitudinal axis, with holes 49 accommodating the articulation rods (see FIGS. 1 and 17).
 FIGS. 18 and 19 are a sectional view of profile examples 20 FIG. 18 and cover 50 FIG. 19 (see FIG. 1). These profiles consist of a secondary arm 15 of the modular elements of the barrier. Profile 20 is U-shaped and the free end 51 of the flanges is folded at a right angle toward the inside, then folded again at 52 at a right angle toward the top, each terminating in clipping boss 53, lower angles 54 being rounded off or broken. Cover 50 is also in an inverted U shape, with the short and finned flanges 55 terminating in a clipping boss 56 complementary to those of profile 20. Core 57 of profile 20 (FIG. 18) is pierced with holes to accommodate the bars (FIG. 20 and 28) that are subsequently swaged and at the pivots, include a punched hole for the insertion of bar 15 through which an articulation pin passes.
 FIG. 20 shows the section of the vertical bars 17 which, with profiles 16, 12, 20 and 50, form the two main and secondary arms of the various modular elements. This profile 17 has a rectangular section with rounded angles 61. The middle of the two inner faces includes a screw recess 60 for attachment between top and bottom profiles 16 (FIG. 23).
 FIG. 21 shows bar 17 of FIG. 20, in the upper and lower ends of which a bearing of plastic 64 can be inserted, and in which the pin pivots.
 FIG. 22 shows a sectional view giving an example of the barrier pivots. It shows profile 16 (see FIG. 1), arms 14 and profiles 20 and 50 of arms 15. Bars 17 (not shown) are attached between profiles 16 defining their horizontal position; pin 65 is inserted in the corresponding holes of the profiles with nuts 66, 67 installed and approached between profiles 16 at the same time together with washers 68 and 69 leaving slight play between nuts 66, 67 and washers 68, 69 to allow arm 15 to pivot smoothly on bearings 64 of pin 65. Flat washers 70 and lockwashers 71 are placed on threaded ends of pin 65, and nuts 72 are locked against their washers, immobilizing pin 65 on the main arm.
 FIG. 23 shows an example of the attachment of bar 17 between two profiles 16 or 20 forming arms 14 and 15 of the various modular elements. Attachment is by four self-tapping screws 75 inserted in the profile passages holes and secured in the screw recesses 60 of the bars. This attaching mode considerably strengthens resistance of the barrier to longitudinal deformation during opening and closing maneuvers. The bars can also be swaged as shown in FIG. 28.
 FIG. 24 shows a sectional view example of a removable floor bearing plate system mounted at each outer pivot of the barrier to compensate for differences in site level, or for curb crossings. It includes a tubular sleeve 80 in which a pin 81 slides vertically over shoulder 82 and lower bearing 83. A bearing plate 84 is attached to lower end of pin 81. There is a compression spring bearing between bearing 83 and shoulder 82. Locking lever 86, hinging at 87 on the system support, has a hole slightly larger than the diameter of the plate pin, so that the edge of the hole locks it in the high or low position under the thrust of spring 88. This system is mounted to be removable on an end bar and abut at the end of lower profile 20. To lower the plate to bear on the ground, upper end 89 of pin 81 is pushed in the direction of arrow 90 to compress spring 85 and, at the same time, the self-locking lever 86 is released by pushing it down through hole 91. To lock the plate on the ground, simply release the lever, which locks against pin 81 under the effect of spring 88. To raise the plate to its rest position, press lever 86, which releases pin 81, lifting it to abut under the effect of spring 85. In areas where the floor is carpeted, the barriers are generally not locked and do not have wheels but rest on larger plates that may slide on the carpet.
 FIG. 25 is a schematic top view of an example of a long barrier according to the invention, consisting of several sections 90, 91, 92 to be assembled on site by means of lock 93.
 FIG. 26 shows an example of an attaching and locking means of two barrier sections secured together. The normal part 95 closing the end of each of the profiles 16 facing each other is extended on the outside by a plate 96 drilled with a large hole 97. An interconnecting plate 98 is made integral with one of closing parts 95 through a belt 99 whose nut 100 is crimped, for instance by three hammer strokes at 120°. Attachment is then provided by a shouldered pin engaged in the hole of the other part 96 and plate 98, while a padlock 102 is inserted into a hole 103 drilled into the end of pin 101 to prevent unauthorized opening.
 FIG. 27 is an elevation example view of a lockable attachment at the end of barrier 105 on a metal post 106 anchored provisionally or definitively on site. Closing part 95 is held in a clevis 107, in which pin 101 is engaged and locked by a padlock 102. Clevis 107 is protected by a threaded pin 108 engaged, for instance, in a hole in web 109 of the U- or H-shaped post, or a metal plate 109 integral with a wall or other support. This pin 108 is locked to said plate after the position of the clevis has been adjusted with respect to the barrier for four nuts 110 with, interposed on either side of plate 109, tapered washers 111 to dampen the forces applied to the barrier.
 FIG. 28 is a perspective view of a detail of the pivot in a secondary arm on the end pivot of a main arm of the modular elements of the barrier according to the invention. The figure callout numbers used above have been used for the same devices. This figure gives better understanding of the assembly of the main and secondary arms on their pivots. We also see the assembly of bars 17 between profiles 16 on main arm 14 and profiles 18 swaged at the top and bottom at 115, 116 in the top and bottom profiles 20 of secondary arm 15. Bar 15 can also be swaged, but this is not necessary because it abuts at either end of the corresponding flanges of profiles 20 and receives two bearings 64 of pivot pin.
 The gaps between bars 17 and 18 of the barrier can be closed by a variety of devices such as cladding sheet metal, corrugated iron, opaque, transparent or translucent plastic panels, laminated glass or light alloy. These fillers can be cut out, except in the case of glass. These various means of closure can be inserted into beading fitted into the small standard light alloy profiles with anti-corrosion treatment, attached to the small sides of the bars. These panels could be provided as a support for advertising posters.