EP2253780A1

EP2253780A1 - Reinforced strut for construction

Info

Publication number: EP2253780A1
Application number: EP09721620A
Authority: EP
Inventors: José Luis Ubiñana Felix
Original assignee: Sistemas Tecnicos de Encofrados SA
Current assignee: Sistemas Tecnicos de Encofrados SA
Priority date: 2008-03-17
Filing date: 2009-01-08
Publication date: 2010-11-24
Also published as: ES2302665A1; UA94872C2; WO2009115626A1; ES2302665B1; EP2253780A4

Abstract

The invention relates to a reinforced strut for construction, formed by a lower base module, an upper supporting module and a variable number of stacked intermediate modules (30, 31) used to vary the overall height of the strut. Each module (30) is provided with a reinforcing plate (32, 37) at each end, said plates having projecting studs and holes used to centre same with the adjacent module (31). In addition, each module (30) is provided with a retractable threaded rod (38) on one of the plates (37) thereof and a threaded socket (33) on the other plate (32) for securing same to adjacent modules (31). This structure can be used for the rapid assembly/disassembly of the strut using resistant modules without parts being exposed to damage during handling.

Description

This invention relates to a reinforced strut for construction which is designed to support large loads.
As is known, the use of struts in construction is widespread and in the case of small or medium loads takes the form of one-piece struts supported on a supporting base at the bottom, for example resting on the ground, with their tops against the item which has to be supported and means to adjust their length and allow easy dismantling. In the case of large loads the struts must have much greater strength characteristics and are normally made of members joined together to obtain the desired height in which there is a lower or base member for the bottom support and a top end member to support the beam or structure that has to be supported. These known struts are characterised in that the members are placed one above the other with the ends of the bars comprising them coinciding with individual couplings which have to be tightened manually in order to secure them.
These known struts have various disadvantages, among which are the vulnerability of the bottom couplings of the members forming the strut during transport and handling, as well as the need to use substantial labour in individually coupling each of the bars or vertical tubular members and individually tightening each of them with tools from the exterior.
The inventor's aim has been to provide a reinforced strut for construction which apart from its high strength properties can also be manufactured simply and assembled and dismantled quickly, in addition to providing special protection for the component modules to prevent damage during handling.
To achieve these aims the reinforced strut to which this invention relates is characterised in that it comprises a number of modules provided with enclosed ends protected by strong abutment plates which have simple very robust centering systems and are attached by a single central rod that can be moved axially at one of its ends, and which can be repositioned by means of a spring and secured in position by a thread.
The strut has a lower base module and another top module to be secured to a beam or the like in the structure requiring support. The base element can be adjusted in height through the simple provision of movable wedges under a single external control and the upper and lower modules have a special double clamp for attachment to the beam of the structure requiring support.
The two upper and lower modules have hemispherical joints incorporating a resilient member which provides a seal and eliminates play, preferably made of neoprene or another appropriate elastomer.
Explanatory but non-restrictive drawings of a preferred embodiment of this invention are provided by way of example to offer a better understanding thereof.

Figure 1 shows a view in elevation of a reinforced strut according to this invention with a sectioned intermediate module and provided with a lower base module and an upper module, but without showing the supporting clamp.
Figure 2 shows a plan view of the strut illustrated in Figure 1.
Figure 3 shows a longitudinal cross-section of the reinforced strut along the section plane shown in Figure 1.
Figure 4 shows a perspective view of a strut with a transversely cut down module, as in Figure 1.
Figures 5 and 6 show the same views of a strut module shown in Figures 1, 3 and 4, in perspective from the bottom and the top respectively.
Figures 7 and 8 show perspective views of other alternative embodiments of the intermediate modules constituting the strut.
Figures 9 and 10 show cross-sections of two strut modules illustrating their attachment through a retractable central rod.
Figure 11 shows a view in lateral elevation of a lower or base module of the strut.
Figure 12 corresponds to a cross-section through the section plane shown in Figure 11.
Figure 13 shows a perspective view of the strut with its lower end incorporated in a beam of the supporting structure.
Figures 14 and 15 show a perspective view and a plan view respectively of one of the main wedges in the lower module.
Figure 16 shows a cross-section of the end of the upper module.
Figure 17 shows a perspective view of the attachment clamp for the upper and lower ends of the strut.

In accordance with the illustration provided in the figures the reinforced strut to which this invention relates comprises multiple modules joined to each other in succession, as indicated by the numbers -1- and -2- in Figure 1, in a variable number depending upon the height of the strut, and supplemented by a lower module -3- for support on the ground or other lower supporting structure and an upper module -4- which is intended to be connected to an upper beam which forms part of the structure requiring support, or a beam of the lower supporting structure as shown in the detail illustrated in Figure 13, which will be explained below. Both lower module -3- and upper module -4- have the same coupling plates -5- and -6- which are designed to be attached to a platen or base of larger dimensions to distribute pressure over the ground and to receive the attachment clamp to the beam of the structure requiring support respectively.
Both lower module -3- and upper module -4- have ball and socket joints in the form of spherical fittings -7- and -8-, ball and socket joint -7- of which is shown in greater detail in Figures 12 and 16.
Figures 5 and 6 show one of the modules of the strut illustrated in Figures 1, 3 and 4 in greater detail. Module -2- is characterised in that both the upper end and the lower end have enclosing plates -9- and -10- which are firmly attached to the tubular members constituting the prismatic cage of module -2- and which are provided with special centering devices of robust construction such as projecting studs -11- and -12- corresponding to two or more of the different bars or tubular members comprising the module such as -13- and -14- illustrated in Figure 5.
In a matching way, plate -10- has housings of diameter matching centering studs -11-, -12-. Figure 6 shows the centering devices in the form of welded annular bodies -15-, -16- and -17- provided with central holes of diameter matching that of centering studs -11-, -12- in the module mounted above. It should be noted that the number of centering studs on bottom face -9- may be only two, as shown in Figure 5, as the stack may initially be centred merely using two centering devices, thus simplifying assembly and manufacture.
Figures 7 and 8 show two variants of the modules of the reinforced strut respectively. Figure 7 shows a module simply formed of columns -18-, -19- and -20- with upper and lower plates -21- and -22-, with a centering structure similar to that shown for module -2- in Figures 5 and 6.
Figure 8 shows a module of greater length comprising longer tubular members -23-, -24- and -25-, transverse reinforcing plates -26- and -27-, and top and bottom plates -28- and -29-. As will be understood, the individual modules may be of greater or shorter length depending on the characteristics of the strut, but the basic structure of the same will be as explained above, and its operation will be identical.
The different modules are attached to each other through a single central rod of the retractable type which connects two stacked modules. This is shown in Figures 9 and 10 which show diagrammatically two stacked modules before and after insertion of the retractable rod respectively. The modules correspond to the embodiment shown in perspective in Figure 7 and are identified by reference numbers -30- and -31-.
As will be seen, the top plate of each module, for example plate -32- of module -30-, has on its lower side a threaded bushing -33- attached to said plate -32- by any means, for example through radial arms -34- which can be seen in Figure 5, without any reference numbers being shown, complemented by a central tubular member -35- receiving fitting -33- which is located at the top within a resilient ring or circlip -36-.
Bottom plate -37- on module -30- has a retractable attachment rod -38- upon which antagonistic spring -39- acts to hold it in the resting position in the position illustrated in Figure 9 in which retractable rod -38- reaches the top in an internal projection -40- through the part of larger diameter -41- or similar means. In this position the bottom end of rod -38- is flush with bottom plate -37-. Both the retractable rod and the threaded fitting in the adjacent module can be dismantled individually in order to be repositioned or repaired, or for other purposes. Part -41-, which is of larger diameter than the central part of rod -38-, has an external thread so that when in the position in which upper module -30- coincides on the lower module -31- the retractable rod can be caused to descend manually and be progressively screwed into the threaded fitting in the lower module, that is to say threaded fitting -42- in module -31-, as shown in Figures 9 and 10. Once screwed in, as shown in Figure 10, the retractable rod remains in the position shown in that figure, in which the two modules -30- and -31- are firmly attached through the mating of their centering devices as explained previously and through retractable rod -38-.
Figures 11 and 12 show the base module indicated by the number -3- in Figures 1, 3 and 4 in greater detail. This module has a device through which a small reduction may be made in the overall length of the strut, which is used primarily to dismantle the strut, given that because the loads exerted on the strut are large it is necessary to "lower" it slightly, that is slightly reduce its length so that it can be easily dismantled. For this purpose there is a device incorporated in module -3- which comprises a system of opposing axial wedges -43- and -44- that are caused to move vertically through a change in the position of two transverse wedges, likewise facing each other, -45- and -46-connected to screw -47- which rotates in internal body -48- incorporated in the module. In this way rotation of screw -47- in one direction or the other causes wedges - 45- and -46- to move apart or together and consequently brings about corresponding axial displacement of axial wedges -43- and -44- in the system of wedges connected at the bottom to foot -49- which is of one piece with ball and socket joint -7-, with the possibility of axial movement between foot -49- and the body of the module.
An internal helical spring -50- causes the system of wedges to recover position, above all for transport.
Figures 14 and 15 show one of the axial wedges, in particular that indicated by number -44-. This wedge is preferably constructed with a hollow structure in order to save weight and the contact surfaces comprise various substantially triangular members which are parallel with each other, such as -69-, -70- and -71-, and have their inclined working surfaces on one side or the other such as those illustrated for one of the sides through numbers -72- , -73- and -74-. These wedge members are conveniently separated leaving an intermediate space of greater width -75- in order to allow passage for thread -47- which activates transverse wedges -45- and -46-.
As indicated in Figure 12, the male part -7- of the ball and socket joint matches the female part -51-, and slight displacements of the bearing can be made in the conventional way. The two wedges -43- and -44- are of similar construction and face each other so that in addition to allowing passage for the thread between them they also prevent interference between each other, as the triangular members of one pass through the spaces in the other and vice versa. A cover -52- is fixed into base -5- through pins -53- pressing an intermediate ring -54- of elastomer such as neoprene or the like which provides a seal and eliminates play.
Figure 13 shows the attachment of the strut to a lower beam forming part of the supporting structure. This view shows an embodiment of the strut constructed using modules of great length -55- and a lower attachment module -3-. It should be pointed out that in this embodiment module -55- has a retractable rod -57- in its lower end which attaches to the upper end of supporting module -3-. The strut is supported on a beam -58- through two double arm clamps -59- and -60-. For greater detail clamp -60- is illustrated in Figure 17 showing plate -61- which fits against the beam with centering studs -62- and -63-, and the two double arms -64- and -65- bearing attachment bolts -66- and -67-. As will be seen, once lower plate -5- of module -3- makes contact with the upper surface of beam -58-, clamps -59- and -60- secure it to said beam -58- causing the strut to be supported on the same and preventing lateral displacements.
Figure 16 shows greater details of the construction of an upper module of the strut, in particular module -4- shown in Figure 1. This module essentially comprises a very strong tubular member -76- which is externally threaded and which engages threaded fitting -77- attached to the module through brackets -78-, -79- and others, this tubular member having at its upper end a ball and socket joint comprising male and female members -80- and -81- in the form of a segment of a sphere, attached through plate -82- with an intermediate neoprene ring -83-. The height of the strut can be varied by screwing tubular member -76- into fitting -77-, adjusting it to the clear height to which it has to extend in the structure. To assist rotation of the tubular member in the thread it has an upper hole -84- for the insertion of a manual tool.
Although the invention has been illustrated by the appended drawings and its operation has been explained in the description provided by way of example, it will be understood that it is not in any way restricted to the said embodiments which in any event are merely in the nature of an explanatory example, so that a number of variants may be incorporated therein while remaining within the scope of the appended claims.

Claims

A reinforced strut for construction, of the type comprising multiple modules joined to each other in succession, with a lower bottom module for support on a lower supporting surface and an upper module to be secured to the structure requiring support, characterised in that each of the individual modules are provided with strengthening and enclosing plates at the top and bottom ends, which bear projecting studs at one end of the module and centering holes designed to receive the said studs at the other end in order to centre each of the two coupled modules, each module having a single central retractable rod in one end for attaching each module of the strut to the adjacent module.
A reinforced strut for construction according to Claim 1, characterised in that the central retractile rod of each module in the stack comprises a body which can be moved axially on a base plate of the module and which is intended to be connected to the module facing it through a male and female connection.
A reinforced strut for construction according to Claim 2, characterised in that the retractable rod of one module is connected to the adjacent module through insertion of the lower threaded portion of the rod which is of greater diameter than the central part of the rod itself into a threaded fitting which is of one piece with the facing module.
A reinforced strut for construction according to Claim 2, characterised in that the retractable rod is provided with an antagonistic spring which is capable of returning it to a resting position in which its bottom surface is flush with the plate of the module on which it is mounted.
A reinforced strut for construction according to Claims 2 and 4, characterised in that both the retractable rod and the threaded fitting in the adjacent module can be individually dismantled for the purposes of repositioning, repair or for other purposes.
A reinforced strut for construction according to Claim 1, characterised in that each module of the strut has a number of projecting studs on the external surface of one of its ends and housings of shape matching that of the said projecting studs on its other external face.
A reinforced strut for construction according to Claim 6, characterised in that the centering members equipped with housings comprise flattened members in the shape of washers or the like welded to the corresponding enclosing plate for the module and provided with a central hole receiving the projecting centering studs of the other module.
A reinforced strut for construction according to Claim 1, characterised in that the lower module supporting the strut on the supporting base has an assembly of two opposing internal wedges which can be moved in relation to each other in the axial direction of the strut and another two transverse wedges connected to the former mounted on a screw fixed to the body of the said foot in such a way that rotation of the thread in one direction or the other corresponds to an adjustment of the axial length of the strut in one direction or the other.
A reinforced strut for construction according to Claim 8, characterised in that the lower axial wedge in the base module is associated with a vertical foot attached at its lower end to a ball and socket with a fixing plate and an intermediate elastomer ring to reduce play and provide a seal.
A reinforced strut for construction according to Claim 9, characterised in that the axial wedges in the base module comprise various substantially triangular members which are parallel to each other, the inclined faces of which provide the supporting surfaces with the transverse wedges and have transverse grooves to permit the screw operating the transverse wedges to be housed.
A reinforced strut for construction according to Claim 1, characterised in that the upper and lower modules of the strut which are coupled to the structure requiring support and the lower supporting structure for the strut respectively are attached to their corresponding structures by means of clamps which can secure the abutment plates of the said modules to the beams forming part of the respective structures.
A reinforced strut for construction according to Claim 11, characterised in that the supporting clamps for the two upper and lower modules of the strut comprise a plate for fitting to the beam bearing centering studs and two double arms at each end bearing bolts which tighten against the upper plate of the strut.
A reinforced strut for construction according to Claim 1, characterised in that the upper module of the strut has a tubular member threaded on its external surface engaging a threaded fitting which is of one piece with the upper part of the module and in which the tubular member has the male part of the ball and socket joint join for the upper plate of the module at the top.