[0001] As stated in the title of this specification, this invention refers to an improved
prop for construction, intended for securing formwork panels and other elements.
[0002] It is of the type that comprises two tubes telescopically coupled via one of their
end sections, while the free ends include certain widened bases for resting on the
ground and for providing a seating for formwork panels and similar.
[0003] The object of the invention concerns certain means for preventing accidental or involuntary
separation of the tubes when they are not being used. A further object of the invention
concerns other means for preventing the separation of the adjusting nut and keeping
it at all times coupled along the entire threaded section of the lower tube.
BACKGROUND OF THE INVENTION
[0004] Props for construction are used for the shoring up of works, for securing formwork
panels, beams, etc. These props generally consist of two telescopic tubes.
[0005] The upper tube is provided with a series of holes arranged a certain distance apart
where a pin is secured. In its upper part, provision is made for a plate which is
what provides the corresponding support for the formwork panel, beam, or similar to
be shored up.
[0006] The lower tube likewise presents a support plate at its lower end for resting on
the ground. At its opposite end it presents a threaded area for the coupling of a
nut with an interior thread, which is provided with certain handles facilitating the
rotation of that nut and with a collar likewise existing in its upper part.
[0007] The adjustment and fastening of the securing position is done by means of the nut
where the pin rests which has been introduced into the corresponding hole of the upper
tube.
[0008] In this type of prop, there exists the problem of separation between the upper tube
and the telescopic lower tube giving rise to problems of losses and damage, in other
words, when the prop has been removed from its shoring up position the upper tube
can become separated from the lower tube.
[0009] In order to prevent these disadvantages, means have been provided which avoid the
separation between the two telescopic tubes.
[0010] So, for example, Invention Patent No. P-9700061 provides for a spring piece fitted
internally in the lower tubular element, said piece being provided with two arms with
end extensions which project along individual diametrically opposed openings of the
lower tubular element and which exert a buffer action against the upper collar fixed
to the adjusting nut.
[0011] Likewise, French Utility Certificate No. 7221681 provides for a similar system and
in this case the buffer device on the upper collar of the adjusting nut consists of
a locking catch which projects from the interior tube via the corresponding spring.
[0012] Utility Model No. U-200400794 refers to a prop which also comprises two telescopically
coupled tubes in which the upper tube possesses in its lower part a countersink adjusted
to the interior diameter of the lower tube; furthermore including a retaining element
integral with the adjusting nut, said retaining element being where the exterior diameter
of the upper tube is adjusted, and at the same time the countersink will rest on that
element in order to prevent the tubes from separating.
[0013] This arrangement described in the above paragraph presents certain problems in construction
and also in assembly.
DESCRIPTION OF THE INVENTION
[0014] With the aim of achieving the objectives and avoiding the disadvantages mentioned
in the above sections, the invention proposes a prop which in principle consists of
an upper tube telescopically coupled within a lower tube which possesses at its free
end a support base on the ground, while the free end of the upper tube also includes
another support base for the surface to be shored up, such as formwork panels for
example.
[0015] The upper tube possesses pairs of facing holes in which a pin is introduced for adjusting
the height of the prop. Nevertheless, in order to adjust that height in a precise
manner, there exists a nut with handles coupled to an upper threaded section of the
lower tube. Said nut includes a collar where the upper tube is adjusted, and at the
same time the said pin will rest on that collar.
[0016] It includes means for preventing accidental separation of the two tubes which are
characterised in that they comprise at least two lugs integral with the upper tube
provided at different heights, at the same time as being found at different generatrices
of the tube; being essentially located in individual diametrically opposed generatrices.
[0017] These lugs are complemented with a small radial open notch in the collar integral
with the adjusting nut, with said collar being what prevents the accidental exit of
the upper tube with respect to the lower one, since one of those lugs acts as a buffer
on that collar. Said notch is arranged in correspondence with the edge of the interior
diameter of the collar.
[0018] In order to carry out the assembly, first one of the lugs (the one closer to the
corresponding free end of the upper tube) is introduced onto that notch; then it is
rotated until the second lug is made to coincide in said open notch.
[0019] In order to carry out a voluntary dismantling, one proceeds in the same way, though
first introducing the lug that is further away from the free end of the upper tube
and then the one that is closer, having previously rotated that tube.
[0020] Another feature of the invention is certain means for preventing displacement of
the adjusting nut to a position in which the coupling between nut and lower tube consists
merely of a small threaded section. For this, the bottom of the nut incorporates a
projecting element which, when the nut is rotated in the upward direction, will come
up against the lower edge of the thread of the lower tube where the adjusting nut
is coupled. This thread projects with respect to the exterior diameter of the lower
tube.
[0021] Below, in order to facilitate a better understanding of this specification and forming
an integral part thereof, some figures are attached representing the object of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022]
Figure 1.- Shows a sectioned elevation view of the improved prop for construction, forming
the object of the invention.
Figure 2.- Shows a plan view of the prop.
DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
[0023] Considering the numbering adopted in the figures, the improved prop for construction
is created on the basis of an upper tube 1 telescopically coupled within a second
lower tube 2, the latter having at its free end a support base 3 on the ground, as
occurs with the upper tube 1 which includes another base 4 at its free end.
[0024] The upper tube 1 in turn incorporates various pairs of facing holes 5 where a pin
6 will be introduced in order to adjust the height of the prop. For this, the pin
6 will rest on a collar 7 integral with an adjusting nut 8 coupled in a projecting
threaded section 9 located in the highest part of the lower tube 2. The nut 8 includes
some handles 10 which facilitate its rotation in order to make fine adjustments to
the height of the prop. The exterior diameter of the tube 1 is adjusted to the interior
diameter of the collar 7.
[0025] The lower part of the upper tube 1 includes two opposite lugs 11 and 12 at different
heights which are located inside the lower tube 2, in such a way that the distance
between them as seen in plan view corresponds to a diametric distance approximately
coincident with the interior diameter of the lower tube 2.
[0026] Thanks to these lugs 11 and 12, when the two tubes are displaced relative to each
other in the axial direction, the upper lug 11 further away from the end of the upper
tube 1 will in principle come up against the collar 7, thereby preventing accidental
separation of said tubes 1 and 2.
[0027] Moreover, the collar 7 includes a small radial notch 13 located in the edge of the
interior diameter of said collar 7, said notch being intended for being able to assemble
the two tubes and also for being able to dismantle them voluntarily. To do this, the
lugs will be made to coincide independently with that radial notch, first one lug
and then the other, after having made the necessary rotation.
[0028] The lower edge of the adjusting nut 8 incorporates a projecting portion 14, such
as a screw, rivet or similar, in such a way that when this nut is rotated in the upward
direction, a moment will be reached when said projecting portion 14 acts as a buffer
against the lower edge of the threaded section 9. In this way, it is ensured that
the stresses of the prop will at all times be borne by the entire threaded section
9 and not just by a part of it.
1. IMPROVED PROP FOR CONSTRUCTION, comprising a lower tube, whose interior is telescopically coupled to an upper tube
with pairs of facing holes in which a pin is introduced which rests on a collar integral
to an adjusting nut coupled to a threaded section located in a highest part of the
lower tube, including first means preventing accidental separation of the lower and
upper tubes, the upper tube being adjusted to an interior diameter of the collar;
characterised in that said means are determined on the basis of at least two lugs (11 and 12) integral
to the upper tube (1), said lugs being at different heights and being in different
generatrices within the lower tube (2); the collar (7) including in an edge of its
interior diameter a radial notch (13) corresponding to said lugs (11 and 12); in order
to prevent accidental separation of the tubes and to enable assembly and disassembly
of said tubes voluntarily.
2. IMPROVED PROP FOR CONSTRUCTION, according to claim 1; characterised in that it incorporates second means limiting an extreme upper position of the adjusting
nut (8), third means comprising an inwards projecting portion (14) integral of the
lower edge of the adjusting nut (8), said portion being complemented with a lower
edge of the upper projecting threaded section (9) of the lower tube (2), the projecting
portion (14) serving as a stop in said lower edge of the projected threaded section
(9) in the highest position of the adjusting nut (8).