Object of the Invention
[0001] The present invention relates to a device which has been especially designed to facilitate
the lowering of towers, both in its raising and in its lowering, in mobile structures
such as for example in structures for services related to show business.
[0002] The object of the invention is to achieve the lowering of said towers quickly, easily
and simply, considerably minimizing the risks of accidents during their handling.
Background of the Invention
[0003] Structures are usually used in outdoor events, which structures are temporarily assembled
on the ground and in which towers of a considerable height participate, on which towers
respective carriages that are able to reach the level determined by the height of
the corresponding tower can usually slide, such that these carriages can carry event
illumination means, cameras for filming the event, etc.
[0004] These shows are normally not very repetitive, on many occasions there is a single
performance in a certain place, such that the lowering of the towers is a constant
and virtually daily task.
[0005] In order to carry out these tower handling operations, manual labor is mainly used
currently, normally with the help of ten people who pull the tower by both sides thereof,
so that the tower passes from the horizontal to the vertical position and vice versa,
a solution that is not very reliable and safe and which evidently further needs a
considerable participation of manual labor.
[0006] The towers are sometimes also lowered with a trapezoidal system using the motor of
the tower, the one for mobilizing the mentioned carriage, in order to pass from the
vertical to the horizontal position, a system entailing unacceptable safety risks.
[0007] The lowering system based on pulling the tower with a cord or rope, pulled manually
with a small forklift truck, is equally unsafe because said cord frequently slides
and even breaks.
[0008] Crane systems are also used to handle the towers, securing them by means of a hook
at its upper end, but evidently this solution is very expensive due to the investment
or the rental required for said crane.
Description of the Invention
[0009] The device for lowering towers proposed by the invention completely and satisfactorily
solves the drawbacks set forth previously, constituting a simple and safe structuring
that is easily handled and completely effective.
[0010] To that end and more specifically, said device consists of a lowering part in the
form of a connecting rod linking in a hinged manner the general and basic structure
on which the base of the tower is secured with the mobile part of said tower, i.e.
with the major part thereof which is joined to the mentioned base in a collapsible
manner, such that the base assembly of the tower-general structure, the mobile part
of the tower and the connecting rod form a deformable quadrangle allowing the mobile
part of the tower to adopt two end positions, a horizontal or lowered position and
another vertical position or position of use.
[0011] In order to change the mentioned mobile part of the tower from one position to another,
a plunger is provided between the middle area of the mentioned connecting rod and
the general structure, the maximum retraction position of which corresponds to the
horizontal or lowered position of the mobile part of the tower, whereas its maximum
extension position corresponds in turn to the vertical arrangement of the mobile part
of the tower.
[0012] The mentioned plunger will preferably be hydraulic, the device having a pressure
pump actuated by an electric motor with the usual mains voltage, i.e. with a rated
voltage of 220-380 V AC current, but obviously it is possible for the mentioned plunger
to be replaced by a "spindle-screw" extension system, in which said spindle will be
directly actuated by an electric motor, with virtually no restriction regarding the
selection possibilities for the mechanism responsible for tilting the connecting rod
or folding part.
Description of the Drawings
[0013] In order to complement the description which is being made and with the aim of aiding
in a better understanding of the features of the invention according to a practical
embodiment thereof, a set of drawings is attached as an integral part thereof in which
the following has been represented with an illustrative and non-limiting character:
Figure 1 shows a schematic side elevational view of a mobile structure and a tower,
the latter being assisted by a lowering device object of the present invention, in
a horizontal position for the tower.
Figure 2 shows a similar view to that of figure 1 but corresponding to an intermediate
lifting phase of the tower.
Figure 3 shows another schematic view similar to those of figures 1 and 2 but in which
the tower is fully upright.
Figure 4 shows a perspective view of the real aspect of part of the structure and
one of its towers in the intermediate handling position of figure 2.
Preferred Embodiment of the Invention
[0014] The general mobile structure, i.e. a structure that can be lowered and transported,
is numbered with (1) in the drawings, which structure participates in assemblies for
outdoor shows and the like and defining for example a rectangular frame, according
to the representation of figure 4, in one or each of the vertexes of which there is
arranged the fixed base (2) of the tower, fixed to the structure (1), base (2) projecting
in height with respect to the structure (1) and receiving, through a hinging shaft
(3), the mobile or lowering part (4) of the tower, which is normally finished at its
upper free end in a crosspiece (5) with pulleys or gear rings for transmitting movement
to belts or chains actuated by a lower electric motor and allowing the raising and
lowering of a carriage that can be used as a work or support platform for different
elements to be installed at the height defined by the tower.
[0015] From this basic and conventional structuring and according to the invention, between
the general structure (1) and the mobile part (4) of the tower, a connecting rod or
lowering part (6) is provided, joined in an articulated manner to the two parts it
links and with which, as can be seen in figures 1 to 3, it forms a deformable parallelogram
in which two of its sides, the ones corresponding or defined by the general structure
(1) and the fixed base (2) of the tower, remain immobile, whereas the two other sides
can change positions, specifically they can vary their inclinations from the position
shown in figure 1 to the position shown in figure 3, respectively corresponding to
the lowered or horizontal situation of the mobile part (4) of the tower and the vertical
situation thereof.
[0016] In order to achieve this change of position in mobile part (4) in a comfortable,
safe and easy manner, between the middle area of the connecting rod (6) and the general
structure (1) there is arranged a plunger (7) which when it is in a maximum retraction
condition determines a maximum inclination position for the connecting rod (6) and
consequently a horizontal position for the mobile part (4) of the tower, shown in
figure (1), whereas as the plunger extends it causes the upward tilting of the connecting
rod (6), with a parallel also upward tilting of the mobile part (4) of the tower,
as shown in figure 2, up to a limit position which must normally correspond to the
maximum extension of said plunger (7), in which the inclination of the connecting
rod (6) has surpassed the vertical and has the opposite sign, in which the mobile
part (4) of the tower adopts a perfectly vertical arrangement as an extension of its
base (2) as shown in figure 3.
[0017] Finally, it must be mentioned that the connecting rod or lowering part (6) and the
plunger (7) must evidently be removed while the mobile structure is in its situation
of use or transport, to that end the general structure and the tower must incorporate
quick coupling/uncoupling means for both the connecting rod and the plunger, the same
occurring with these elements between each other, such that a single device can also
be used in the multiple towers that can participate in a certain structure.
1. A device for lowering towers in mobile structures, such as for example in structures
related to show business, wherein said towers have a short base rigidly joined to
the general structure and to which a major mobile part is joined in a hinged manner
and can adopt a vertical arrangement as an extension of its base, or a horizontal
lowered position on the general structure, characterized in that it consists of a connecting rod or lowering part which is joined in an articulated
manner at its ends to the general structure and to the mobile part of the tower, such
that with these elements and with the base of the tower it forms a deformable parallelogram,
in which in the limit lowered position in which the mobile part of the tower adopts
a horizontal position, the connecting rod adopts a pronounced inclined arrangement
from which it progressively tilts towards the vertical as the mobile part of the tower
also tilts towards the vertical, adopting an inclination in the opposite direction
in the limit situation in which said mobile part of the tower is located in a vertical
alignment with the base thereof, said connecting rod or lowering part having actuation
means thereof in the tilting direction.
2. A device for lowering towers in mobile structures according to claim 1, characterized in that said actuation means of the connecting rod or lowering part consist of a plunger
arranged between a middle point of the connecting rod and the general structure, joined
in an articulated manner to these elements and actuated by a hydraulic pump which
is in turn actuated by an electric motor, all of this such that in the maximum retraction
situation for said plunger, the mobile part of the tower adopts a horizontal position,
whereas in the maximum extension position for the plunger the mobile part of the tower
adopts a vertical position.