[0001] This invention relates to a reinforced strut for construction which is designed to
support large loads.
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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-.
[0015] 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-.
[0016] 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-.
[0017] 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.
[0018] An internal helical spring -50- causes the system of wedges to recover position,
above all for transport.
[0019] 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-.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. 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.
12. 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.
13. 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.