A portable structure with a self-supporting working platform for accessing difficult to access areas

Abstract

The invention relates to a portable structure for ascending and descending to inaccessible places, with a self-supporting working platform, the structure being of the kind formed by three legs, one of which is a ladder, which are close to each other at the top where the working platform is located, where the three legs are joined. The three legs are composed of corresponding supports and corresponding ladders, each of the three legs is connected to the working platform at two connection and support points distant from each other, and angled mounting means are provided at one of the two connection points of each leg to prevent twisting of the legs and to establish a triangular distribution of forces. The portable structure formed thereby does not require a reinforcing structure in the intermediate areas between the different legs.

Description

[Technical field]

[0001] The present invention relates to the field of portable structures for ascending and descending difficult to access places, such as step ladders, ladders or scaffolding, and in particular to a portable structure comprising a working platform for ladder users, the working platform having one or more ladders for accessing the working platform and converging legs formed by one or more supports.

[0002] For ease of explanation, the portable structure will be referred to below as a portable ladder, but everything said about that structure is applicable to stepladders and scaffolds having three supporting legs. [Background technology]

[0003] Portable ladders or stepladders can be divided into two groups. Supported ladders or stepladders. These are ladders that are unstable in themselves and must be supported by a climbing element such as a wall or façade. Freestanding ladders or step ladders. These ladders can support themselves, the most common ladder in this group is the so-called scissor ladder. In many cases, freestanding ladders can be used as supported ladders.

[0004] Among so-called self-supporting ladders of this kind, embodiments are known in which the so-called support legs consist of three legs which approach each other at the top of the ladder, the three legs being formed by one or more ladders and one or more supports.

[0005] US Pat. No. 5,399,633 and US Pat. No. 5,499,625 show structures with three ladders that function as legs, but neither has a working platform.

[0006] US Patent No. 5,399, 663 shows a structure formed by two supports and one ladder, with three legs each rotatably connected to a small upper triangle, whereby each element is articulated and connected to one of the sides of the small upper triangle that is not the working scaffold itself. US Patent No. 5,399, 663 and US Patent No. 5,399, 677 show a similar structure, but with three ladders.

[0007] US Pat. No. 5,399,633 shows a structure also formed by two support legs and a ladder, with a seat at its top instead of a working platform.

[0008] Patent document 7 discloses a top work platform and three support legs. Patent document 7 shows a ladder with three support legs, two of which are supports and the third is a ladder with rungs, which terminate at the top in a rectangular work platform with handrails.

[0009] As well as the two supports, the ladder has a central tubular element, i.e. a tubular embodiment with a circular cross section, whereby the connections between the three legs and the scaffold are made by means of linking pins.

[0010] However, this arrangement presents a fundamental problem inherent in ladders having three supporting legs, namely, twisting of the supporting legs and subsequent tipping of the ladder, with the attendant risk of serious injury to the user.

[0011] This problem is exacerbated if the ladder is placed on a floor that does not provide adequate friction at the support points of the legs and is extremely dangerous if the ladder is placed on a slippery floor.Obviously this arrangement cannot be applied to ladders that have a rolling element at at least one of its three support leg points that contact the floor.

[0012] On the other hand, this arrangement requires means to limit the opening of the support legs. Indeed, if one wishes to prevent twisting effects and limit the opening angle of the ladder's support legs, it is necessary to use a flange-like frame connected to the three support legs, which defines a structure in the form of a contoured reinforcing ring at the middle height of the ladder, in a horizontal plane parallel to the floor. This arrangement, in addition to being completely ineffective on slippery floors and on supports with wheels, means that the embodiment of the ladder is complicated, since it is necessary to provide elements constituting the reinforcing ring. Moreover, it makes the assembly and storage of the ladder very complicated and increases its weight, which is very disadvantageous for portable manual ladders.

[0013] Furthermore, in order to simplify the deployment and storage of the ladder, a compass-like embodiment is used in which each flange-type element connecting the two support legs allows it to be deployed and stored in an articulated manner without the need to be disassembled, but this embodiment still involves additional weight and further complicates the ladder embodiment in that it requires the provision of a hinge for the compass and a safety means on said hinge to prevent unintentional closure.

[0014] Another drawback of known configurations is that the opening angle of the legs is fixed, which makes it impossible to assemble the ladder in locations where it is not possible to overcome obstacles such as nearby walls or obstacles that must be placed under the ladder.

[0015] On the other hand, these configurations do not provide adequate rigidity in the connection between the support legs and the working platform, which also poses a danger to the user. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] French Patent No. 344595 [Patent Document 2] British Patent No. 190405121 [Patent Document 3] US Patent Application Publication No. 2015 / 345219 [Patent Document 4] U.S. Pat. No. 5,685,391 [Patent Document 5] British Patent No. 2341883 [Patent Document 6] DE 2141074 A1 [Patent Document 7] European Patent Application Publication No. 1079062 Summary of the Invention [Problem to be solved by the invention]

[0017] Considering the shortcomings of existing arrangements, it is apparent that a solution is needed. [Means for solving the problem]

[0018] The present invention relates to a portable structure for ascending and descending to difficult to access places, such as a stepladder, which achieves this object, solves the technical problems mentioned above so far, and also provides additional advantages as shown below. It comprises three legs approaching each other at the top of which a working platform is located, characterized in that it is self-supporting. This working platform physically or theoretically defines at least three straight lines, to which the three legs, consisting of a support or a similar number of supports and a ladder or a similar number of ladders, are assembled. In particular, each of the three legs is connected to the working platform at two connection points spaced apart from each other, so that each leg is provided with two connection and support points spaced apart from each other, at least one of the two support points is provided with an angled attachment means, which makes it possible to prevent twisting of the legs even on slippery floors and also to establish a triangular distribution of forces.

[0019] In this way, the portable structure formed therefore does not need to have in its intermediate region flange elements for installing reinforcing rings between the different legs at intermediate heights for a self-supporting working platform.

[0020] Furthermore, this configuration allows the legs to assume variable angular positions and the user can fix the angle at their discretion, which allows the ladder to be assembled next to an obstacle such as a wall or to go over obstacles such as stones, barriers, cars, etc. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a portable structure formed by a movable ladder incorporating an arrangement of the present invention; [Diagram 2] FIG. 2 is a front view of the ladder of the previous figure. [Diagram 3] FIG. 3 is a top view of the ladder of FIGS. [Figure 4] FIG. 1 is a perspective view of a retractable ladder having eight rungs made in accordance with the present invention. [Figure 5-6] 5A and 5B are side and front views, respectively, of the ladder of FIG. [Figure 7] FIG. 1 is a perspective view of a retractable ladder having 12 rungs made in accordance with the present invention. [Figure 8-9] 8A and 8B are side and front views, respectively, of the ladder of FIG. 7. [Figure 10] FIG. 1 is a perspective view of a working scaffold (1). [Figure 11-13] 11A and 11B are top, side and bottom views, respectively, of the work scaffold (1) of FIG. 10. [Figure 14] FIG. 1 is a perspective view showing a modified embodiment of a divided work scaffold (1). [Figure 15] FIG. 1 is a perspective view of a portion of a ladder working platform (1) made according to the invention, in which the disk (1.10) with the opening and the ratchet (1.8) are visible, the ratchet (1.8) being in the closed position corresponding to the working position of the ladder. [Figure 16] FIG. 2 shows an enlarged detailed view of the disk (1.10) and ratchet (1.8) in the closed position corresponding to the previous view. [Figure 17] 16 is a perspective view similar to FIG. 15, but with the ratchet (1.8) in the raised position. [Figure 18]An enlarged detailed view of the disk (1.10) and ratchet (1.8), with the ratchet (1.8) in the raised position as in the previous view. [Figure 19] A perspective view of the working platform (1) from the bottom, with the rotating structure (1.6) folded under the working platform (1) and the journals (1.7) of the ladder legs (3.1) unfolded. [Figure 20] 15 and 17, but showing the ratchet (1.8) in the retracted position. [Figure 21] FIG. 16 is an enlarged detailed view of a portion of the ratchet (1.8) in a closed position similar to that shown in FIGS. 15 and 16, but according to a variant of the actual embodiment, the ratchet (1.8) is provided with a thread spring (1.21) and the journal (1.7) is provided with fixing means (1.20) that can be adjusted to adapt the journal (1.7) to the dimensions of the longitudinal members of a conventional ladder leg (3.1). [Figure 22] FIG. 1 is a detailed perspective view of the working platform (1), in which the central opening (1.23) of the working platform (1) and the attachment (1.7.1) of the journal (1.7) can be seen. [Diagram 23] Similar to FIG. 1, but with two quick fastening mechanisms (5) on the legs (3.2). [Figure 24] FIG. 2 is a perspective view of the interior of each quick fastening mechanism (5) with one of the two metal plates (9) removed to allow the internal elements of the quick fastening mechanism (5) to be seen. [Diagram 25] FIG. 1 is an elevational view showing the quick fastening mechanism (5) placed on the tubes (3.4, 3.5). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention relates to a portable structure for accessing difficult to access places, such as a stepladder, which comprises a self-supporting working platform (1) as described below. The working platform (1) is arranged on three legs (3.1, 3.2, 3.3) which converge towards each other at the top towards the working platform and which define respective contact points (4) with the floor at the bottom.

[0023] According to a non-limiting practical embodiment, as shown in figures 1, 2 and 3, the working platform (1) comprises a fence (2) which comprises handrails (2.1) for protecting the person or people on the working platform (1) from the risk of accidentally falling. This fence (2) can be complemented with other means (2.2) for carrying out functions such as, for example, hanging tools, providing electrical wiring, assembling winch-type means for lifting and lowering heavy loads, preferably detachable auxiliary elements, or any other means that may be required by the workers on the working platform (1).

[0024] According to a practical, non-limiting embodiment shown in the attached drawings, at least one of the legs (3.1, 3.2, 3.3), specifically in this case the one identified by the reference (3.1), is a ladder formed by two uprights and corresponding rungs. Although the legs (3.2, 3.3) are simple supports, it is clear that two of the three legs, or even all three legs, may be ladders. Thus, at least one of the three legs (3.1, 3.2 and / or 3.3) is a ladder to allow ascending and descending from the working platform (1).

[0025] The embodiment with three legs (3.1, 3.2, 3.3) can correspond to any conventional solution known so far. In this sense, the ladder leg (3.1) can have a different number of rungs, can be constituted by a single ladder or by two or more ladders, can be rigid, articulated or telescopic, etc. Furthermore, the ladder leg (3.1) can be an embodiment formed by a single central longitudinal member passing through the rungs, instead of two longitudinal members with corresponding rungs extending laterally between them.

[0026] The same applies to the simple support leg (3.2, 3.3), which may be a single piece or may consist of several pieces connected together or in a telescopic assembly or the like.

[0027] The contact points (4) with the floor surface can also be of any conventional embodiment known hitherto or which may arise hereafter, consisting of the legs (3.1, 3.2, 3.3) themselves, auxiliary elements such as rubber ferrules, rolling means, or a combination of these elements.

[0028] Corresponding to the one shown in figures 1, 2, 3, figures 4, 5, 6 show a retractable ladder with 8 rungs, while the ladder in figures 7, 8, 9 has 12 rungs. As shown in figures 7, 9, the actual structure of the ladder can be such that some or all of the auxiliary elements such as the railing (2) and its handrail (2.1) can be folded up therein.

[0029] Figures 10 to 13 show possible practical embodiments of the working scaffold (1), which preferably has a basic configuration of a triangle with the apex truncated, defining a flat upper part (1.1) supporting the user and a bottom part (1.3) optionally provided with reinforcing ribs (1.2) depending on the thickness and material of the working scaffold (1).

[0030] The upper part (1.1) of the working platform (1) may have a non-slip treatment, either by itself or by means of a secondary covering. The reinforcing ribs (1.2), if present, are arranged radially at 120° to each other, according to a preferred but non-limiting embodiment, as shown in figures 10 and 13.

[0031] Furthermore, Figure 14 shows a divided embodiment of the working platform (1), preferably divided into three parts identified by the reference number (1.4), whereby each of the three parts (1.4) is connected to one of the legs (3.1, 3.2, 3.3). In this embodiment, the three legs (3.1, 3.2, 3.3) can be separated from each other and placed adjacent to each other side by side, in order to take up as little space as possible when folding the ladder and storing or transporting it.

[0032] As shown in FIG. 14, according to a possible practical embodiment, which is not limiting, the working platform (1) has a rotating structure (1.6) on each side thereof connected to one of the legs (3.2, 3.3), which preferably has an inverted triangular arrangement with two V-shaped parts connected to a horizontal part.

[0033] The rotating structure (1.6) has a journal (1.5) at the apex of the V-shaped section to allow removable assembly of the legs (3.2, 3.3).

[0034] The scaffold (1) has, on the side connected to the ladder leg (3.1), two journals (1.7) so that the ladder leg (3.1) can also be removably assembled. Furthermore, in this embodiment, the legs (3.1, 3.2 and / or 3.3) can consist of commercially available conventional elements, provided that the journals (1.5, 1.7) are adapted to the dimensions of conventional elements or are provided with adjustment and tuning means for adapting to the dimensions of such conventional elements, as shown below.

[0035] According to a preferred practical, but not limiting, embodiment, the two journals (1.7) for the ladder legs (3.1) can each rotate in an articulated manner about a rotation axis (1.18) to move from an extended or working position to a stowed or folded position in which they are arranged under the scaffold (1).

[0036] This allows the simplest possible single-length or extendable stepladder to be positioned at an angle between 70.5° and 75.5° with respect to the floor horizontal. For this value, for at least one of the two journals (1.7) for the ladder legs (3.1), next to its axis of rotation (1.18), as shown in figure 14, there is a pin (1.19) acting as a stopper, thereby limiting the opening of the ladder legs (3.1) to a value preferably around 70°.

[0037] For the simple support legs (3.2, 3.3) there are means by which their opening positions can be fixed over 360°, for which, according to a preferred practical but not limiting embodiment, such means consist of a disk (1.10) with a number of openings (1.11) distributed circumferentially around the axis of rotation (1.22) of the disk (1.10).

[0038] As shown in FIG. 15, the above-mentioned disk (1.10) is mounted on one end of the horizontal part of a rotating structure (1.6) that supports a journal (1.5) and can rotate around the rotation axis (1.22) of the rotating structure (1.6).

[0039] In this way, the legs (3.2, 3.3) can be fixed in a number of angular positions, as many as there are openings (1.11) in the disk (1.10), by passing a pin (not shown) through one of the openings (1.11), making it possible to position and fix the legs (3.2, 3.3) through 360°.

[0040] This method consisting of a pin can be replaced by any known fastening method, such as an embodiment that acts automatically by means of an arrangement consisting of a ball pressed by a spring.

[0041] In this way the legs (3.2, 3.3) can be fixed in the deployed position at an angle of 360°.

[0042] As shown in Figures 15 and 16, a cam part (1.15) having a recess on its outer periphery, preferably two recesses identified by the reference characters (1.14, 1.17), is arranged on the other rotation axis of the rotating structure (1.6) identified by the reference character (1.16).

[0043] In association with this cam element (1.15) is arranged a ratchet (1.8) which can rotate about an axis (1.9) to a stable position limited by a stop pin (1.13).

[0044] In the deployed position of the ladder, which corresponds to the working position shown in figures 15 and 16, the ratchet (1.8) assumes its closed position accommodated in the recess (1.14) of the cam element (1.15) and fixes this position.

[0045] In figures 17 and 18 the ratchet (1.8) is shown manually lifted and removed from the recess (1.14), which, when released from the lock set by the disk (1.10), allows the swinging of each of the two rotating structures (1.6) about their axes (1.16, 1.22) and the movement of the legs (3.2, 3.3), if they are assembled on the journal (1.5), both to change the angle of support on the floor and to move from the working position to the storage position and vice versa.

[0046] Figures 19 and 20 show the two rotating structures (1.6) in the folded storage position under the working platform (1). As shown in these two figures 19 and 20, in the stored position of the two rotating structures (1.6), the ratchet (1.8) is received in the recess (1.17) of the other of the cam parts (1.15).

[0047] As regards the two journals (1.7) of the ladder leg (3.1), in addition to the presence of a stop (1.19) for one of them, it is also envisaged to incorporate on that journal an arrangement consisting of a ratchet (1.8) and a cam element (1.15) which can be installed on one or both of the two journals (1.7) as described above.

[0048] Figure 21 shows a variant of the practical embodiment, according to which for each ratchet (1.8) there is arranged a spring-type elastic means (1.21) or the like which keeps the ratchet (1.8) in a stable contact position with respect to the cam element (1.15). According to the practical embodiment shown in this non-limiting example, the elastic means (1.21) consists of a thread-like spring assembled to the pivot (1.9) of the ratchet (1.8).

[0049] According to what has been described so far, a portable structure for ascending and descending like a ladder to inaccessible places has three legs (3.1, 3.2, 3.3) approaching each other at the top on a working platform (1), at least one of which is a ladder leg (3.1) for enabling ascent and descent onto the working platform (1), in which case the other two legs (3.2, 3.3) are support legs.

[0050] The ladder leg (3.1) has a stopper (1.19) for limiting the opening angle of at least one of the two rotating journals (1.7) rotatably assembled to the working platform (1), and a ratchet (1.8) for at least the other journal (1.7) that can take at least three positions: a closed position corresponding to the deployed or working position of the ladder leg (3.1), another raised position allowing the ladder leg (3.1) to rotate, and a third retracted position corresponding to the state in which the above-mentioned journal (1.7) is retracted under the working platform (1).

[0051] Each support leg (3.2, 3.3) is then assembled to a rotating structure (1.6) which can rotate at two points relative to the working platform (1), and for at least one of the two rotating ends of this rotating structure (1.6) there is a fixing means formed by a disk (1.10), which end, the opposite end or both ends can optionally have a configuration consisting of a ratchet (1.8).

[0052] Thus, each ladder leg (3.1) may have for each of the two rotating journals (1.7) a stop (1.19) for limiting the opening angle and a locking ratchet (1.8). According to a variant of the actual embodiment, each ladder leg (3.1) may have a stop (1.19) for one journal (1.7) and a ratchet (1.8) for the other journal (1.17).

[0053] Each of the two support legs (3.2, 3.3) has, at least at one of the two connecting ends of its rotating structure (1.6), a disk (1.10) for fixing the angle that the leg (3.2, 3.3) must take with respect to the floor. Optionally, as a variant of the actual embodiment, it has an arrangement consisting of a disk (1.10) for one of its rotation points and a ratchet (1.8) for the other rotation point.

[0054] In any of these possible embodiments, each leg (3.1, 3.2, 3.3) has two spaced apart connection and support points to the working platform (1), at least one of which is provided with an angled attachment means, which prevents the leg (3.1, 3.2, 3.3) from twisting relative to the working platform (1), provides self-support and also allows for a triangular distribution of forces.

[0055] Moreover, this stability is maintained even when the ladder is used on slippery floors and when some or all of the legs (3.1, 3.2, 3.3) are equipped with rolling means.

[0056] In case the ladder is intended for use on non-slip floors and has support points (4) on the floor by means of high friction ends, each leg (3.1, 3.2, 3.3) has two separate connection points for supporting each leg to the working platform (1), and the number of ratchets (1.8) and the number of discs (1.10) can be reduced while still maintaining the essence of the invention, as long as angled attachment means for each leg (3.1, 3.2 and / or 3.3) are provided at at least one of the two points.

[0057] Thus, for example, a practical embodiment variant with a very simple relationship is that of a ladder as shown in the accompanying drawings, in which for its ladder legs (3.1) there is a ratchet (1.8) for one of its journals (1.7) and a stopper (1.19) for the other journal (1.7). For the support legs (3.2, 3.3), the rotating structure (1.6) of each leg has a disk (1.10) for one of two separate points where it is connected to the working platform (1).

[0058] Variations of the embodiment with mixed configurations, envisaged in particular for slippery floors or with support points (4) formed by rolling elements, are also conceivable and very simple, as long as the essence of the invention is maintained, that each leg (3.1, 3.2, 3.3) has two mutually distant connection points to the working platform (1) for supporting each leg (3.1, 3.2, 3.3) relative to the working platform.

[0059] In an embodiment of the working scaffold (1) according to the invention, a triangulation of forces that the ladder must withstand is established, which, together with the provision of angled attachment means for each leg (3.1, 3.2 and / or 3.3) at at least one of the two distant connection points for the legs (3.1, 3.2, 3.3), makes it possible to eliminate the need for a flange-type element defining a central support parallel to the floor at mid-height of the ladder.

[0060] Furthermore, in this configuration, the legs (3.1, 3.2 and / or 3.3) can take variable angular positions and the user can fix the angle at his discretion, which allows the ladder to be assembled next to obstacles such as walls or over obstacles such as stones, barriers, cars, etc.

[0061] On the one hand, it is envisaged that each journal (1.7) is provided with adjustable fastening means (1.20) making it possible to introduce and fasten therein the upper ends of the uprights of conventional ladder legs (3.1). In this way, the working platform (1) can be adapted to be coupled to conventional ladders directly available on the market. According to a non-limiting practical embodiment, these fastening means (1.20) can be simple screws, as shown in figure 21. A similar arrangement applies to the journals (1.5), thereby giving the working platform (1) a universal character.

[0062] Furthermore, as shown in figure 22, the journal (1.7) can be provided with adapting parts (1.7.1) defining bends which can be at different angles in order to allow the assembly of ladder legs (3.1) of various widths, within the concept of universal nature. The function of these auxiliary adapting parts (1.7.1) can also be provided by the journal (1.7) itself, so that the journal (1.7) and its adapting parts (1.7.1) form a single part.

[0063] As shown in Figure 22, the scaffold (1) has a central opening (1.23) into which a hoist-type lifting element or similar can be assembled, allowing the portable structure to function like a winch for lifting and lowering significant weights, people, etc.

[0064] Although the attached drawings show a scaffold (1) with a truncated triangular configuration, this configuration must be understood as a non-limiting practical embodiment in that the scaffold (1) may have a polygonal, circular, elliptical or mixed straight and curved contour base, provided that it allows the two connection points for connecting the legs (3.1, 3.2, 3.3) to the scaffold (1) to be placed in three physical or theoretical lines that define the contour of the triangle. Thus, for example, in the truncated triangular embodiment of the scaffold (1) shown in the attached drawings, the two connection points of each leg (3.1, 3.2 or 3.3) are located relative to one of the sides of the scaffold (1), but it is also possible, for example, for the scaffold (1) to have a circular base, below which the two connection points for the legs (3.1, 3.2, 3.3) can be set in three possible physical or theoretical lines by ribs or in a similar manner, but the lines in any case define a triangle.

[0065] In the embodiment where the legs (3.1, 3.2 and / or 3.3) are formed by two or more telescopic tubes, there are of course methods for fixing the length of the telescopic tubes in the desired position. If the tubes are cylindrical, the smaller diameter tube identified by the reference (3.4) is fixed in its selected position within the larger diameter tube (3.5), so that the legs (3.1, 3.2 and / or 3.3) have the longitudinal dimension required in each case.

[0066] This fixing can be done by a very simple construction, such as providing the tubes (3.4, 3.5) with a mutual relationship of openings so that a pin can be passed through a selected pair of openings, but it can also be done by using a more complex quick-fixing mechanism, as shown by the non-limiting practical embodiment in Figures 23, 24 and 25, identified by the reference number (5).

[0067] For ease of illustration, only two quick fastening mechanisms (5) are shown for leg (3.2), however the other two legs (3.1, 3.3) would also have their own quick fastening mechanisms (5) if the telescopic tube embodiment is adopted. Furthermore, each leg (3.1, 3.2 and / or 3.3) would have as many quick fastening mechanisms (5) as there are pairs of tubes (3.4, 3.5), i.e. in this case leg (3.2) would require two quick fastening mechanisms (5) since it is made up of three tubes.

[0068] In this embodiment shown in FIG. 23, the legs (3.2, 3.3) have quick fastening mechanisms (5), each of which (3.2, 3.3) has two quick fastening mechanisms (5) by virtue of being telescopic and made up of three tubes, but for ease of illustration, only the quick fastening mechanism (5) of leg (3.2) is shown.

[0069] As shown in Figures 24 and 25, each quick-fixing mechanism (5) consists of two identical metal plates (9) with openings (11) through which fastening screws pass, by means of which the plates (9) are fixed to the larger diameter tube (3.5) through the inside of which the smaller diameter tube (3.4) can move.

[0070] Between these two plates (9) two jaws (6) are arranged. As shown in Figure 25, each jaw (6) is integrated with a pin (14) assembled between two side plates (13). Each side plate (13) can swing relative to the pin (15). A pin (7) that can be pushed in by the user of the portable structure of the invention is also assembled between these side plates (13).

[0071] Two flat plates (12) connected to pins (7) are also positioned on the sides of each jaw (6). Each side plate (12) has an elongated arcuate opening (16) which, together with a pin (17) limits the arcuate movement of the side plate (12), as shown in FIG.

[0072] Each jaw (6) is held in a stable position against the tube (3.4) by the action of a respective elastic element (8), such as a spring, as shown in FIG.

[0073] With this whole properly arranged, the user of the portable structure can, with only one hand, operate the two pins (7) of each quick-locking mechanism (5) and raise the structure against the action of the elastic element (8), so that the two jaws (6) move away from the tube (3.4) and free it so that the tube (3.4) can move inside the tube (3.5). When this force is removed, the elastic element (8) fastens the jaws (6) to the tube (3.4), fixing the tube (3.4) in its current position.

[0074] With this construction, the greater the tendency of the tube (3.4) to move so as to be inserted into the tube (3.5), the stronger the fixation of the jaws (6) to the tube (3.4) and the more firmly the tube (3.4) is fixed in the position it currently lies in.

[0075] A pin (10) that serves to stop the movement of the tube (3.4) inside the tube (3.5) is mounted on the flat plate (11).

[0076] In addition to providing a quick fastening mechanism (5) that can be operated with one hand, this configuration ensures that the jaws (6) are always positioned perpendicular to the longitudinal axis of the legs (3.1, 3.2 and / or 3.3) in order to better perform their function. Furthermore, this configuration allows the jaws (6) to have appendages such as coatings or rubber lips that prevent deterioration of the telescopic tubes that form the legs (3.1, 3.2, 3.3).

Claims

1. A portable structure for accessing inaccessible places with a self-supporting working platform, said structure being of the kind formed by three legs, at least one of which is a ladder, said legs approaching each other at the top where the working platform is located, said three legs (3.1, 3.2, 3.3) consisting of a support or a number of similar supports and a ladder or a number of similar ladders, connected to the working platform (1), each of said three legs (3.1, 3.3.1, 3.2, 3.3) being connected to the working platform (1), is connected to the working platform (1) at at least two connection and support points spaced apart from one another, and at least one of the two connection points of each leg (3.1, 3.2, 3.3) is provided with angled attachment means for the corresponding leg (3.1, 3.2 or 3.3) in order to prevent twisting of the legs (3.1, 3.2, 3.3) and to establish a triangular distribution of forces, whereby the portable structure formed does not require reinforcing structures in intermediate areas between the different legs (3.1, 3.2, 3.3).

2. 2. A portable structure for accessing inaccessible places with a self-supporting working platform according to claim 1, characterized in that the connection between the two connection points of each leg (3.1, 3.2, 3.3) to the working platform (1) comprises at least an angled attachment means for the corresponding leg (3.1, 3.2 and / or 3.3) at one of the two connection points, in order to be able to selectively fix the angle between the leg (3.1, 3.2, 3.3) and the working platform (1).

3. 3. A portable structure for accessing inaccessible places with a self-supporting working platform according to claim 1 or 2, characterized in that each support leg (3.2, 3.3) is connected to the working platform (1) via a rotating structure (1.6) of the working platform (1), the rotating structure (1.6) having two V-shaped parts and a horizontal part parallel to one side of the working platform (1) by means of its ends establishing two separate points for the rotatable connection of the support legs (3.2, 3.3) to the working platform (1).

4. 4. A portable structure for ascent to inaccessible places with a self-supporting working platform as claimed in any one of claims 1 to 3, characterized in that the rotating structure (1.6) has, at the apexes of its two V-shaped parts, journals (1.5) to which the upper parts of the corresponding supporting legs (3.2, 3.3) are fixedly or removably connected.

5. 2. A portable structure for accessing inaccessible places with a self-supporting working platform as claimed in claim 1, characterized in that each ladder (3.1) is connected to the working platform (1) via two connections spaced apart from each other, said connections establishing an articulated connection, preferably two journals (1.7) into which the upper ends of the ladders (3.1) are inserted.

6. 2. A portable structure for accessing inaccessible places with a self-supporting working platform as claimed in claim 1, characterized in that the working platform (1) has a flat configuration with a polygonal contour having at least three straight sides, to which the three legs (3.1, 3.3.1, 3.2, 3.3) are assembled.

7. 7. A portable structure for accessing inaccessible places with a self-supporting working platform as described in claim 6, characterized in that the working platform (1) has a flat configuration with a mixed straight and curved contour with reinforcement on the underside formed by reinforcing ribs (1.2) extending radially from the central part.

8. A portable structure for ascent to inaccessible places with a self-supporting working platform as described in claim 7, characterized in that the working platform (1) can have a divided structure formed by three parts (1.4), each part being connected to one of the three legs (3.1, 3.3.1, 3.2, 3.3).

9. 5. A portable structure for ascent to inaccessible places with a self-supporting working platform according to claim 1, 3 or 4, characterized in that the rotating structure (1.6) has a triangular basic configuration, one of its sides is arranged horizontally and adjacent to the corresponding side of the working platform (1), both ends of which establish an interlocking connection with the working platform (1) itself, and the other two sides are arranged in a V-shape, at the apex of which a journal (1.5) is arranged.

10. 5. A portable structure for ascent to inaccessible places with a self-supporting working platform as claimed in any one of claims 1, 3 or 4, characterized in that at least the supporting legs (3.2, 3.3) are provided with means for fixing the position of said supporting legs (3.2.2, 3.3) in a configuration in which the angle they form with respect to the floor, relative to one of their connection points, varies through 360°, said means being preferably formed by a disk (1.10) with a number of openings (1.11) arranged in a circumferential direction, each opening (1.11) defining a different angular position of the supporting legs (3.2, 3.3).

11. 6. A portable structure for ascent to inaccessible places with a self-supporting working platform as claimed in claim 1 or 5, characterized in that it has a ratchet (1.8) for establishing, at least with respect to the ladder legs (3.1), at least two stable positions of the journal (1.7), said two stable positions being an operating position in which the journal (1.7) is unfolded and another folded position in which the journal (1.7) is stored under the working platform (1).

12. 6. A portable structure for ascent to inaccessible places with a self-supporting working platform according to claim 1 or 5, characterized in that for one of the two journals (1.7), it has a stop (1.19) acting in the deployed position of the journal (1.7).

13. 6. A portable structure for accessing inaccessible places with a self-supporting working platform according to claim 1 or 5, characterized in that each of the journals (1.7) comprises adjustable fastening means (1.20) which allow the upper ends of the longitudinal members of conventional ladder legs (3.1) to be introduced therein and fixed.

14. 14. A portable structure for ascent to inaccessible places with a self-supporting working platform according to claim 1, 5 or 13, characterized in that at least one of the journals (1.7) is additionally or integrally provided with an adapting part (1.7.1) so that the journal (1.7) can be adapted to ladder legs (3.1) of various width dimensions.

15. 2. A portable structure for accessing inaccessible places with a self-supporting working platform according to claim 1, characterized in that an opening (1.23) or a similar arrangement for mounting a load lifting device acting as a winch is provided in the central area of ​​the working platform (1).

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