[0001] This description relates, as its title indicates, to a safety brake for a tower mast
formed by several telescopic segments used normally for light, surveillance or communication,
which prevents the total or partial collapse of the mast due to its malfunction, by
means of one or several retractable reels, on which is wound a belt, cable or rope,
finished at its free end in a securing piece. The retractable reel has means for winding
and unwinding the said belt, cable or rope inside it and has means for detecting a
higher acceleration in the extraction of the belt, cable or rope than that preset,
as well as having means for blocking and stopping the unwinding of the belt, cable
or rope in such a case.
Field of the invention
[0002] The invention relates to the field of light, surveillance or communication towers,
in particular, those that have a telescopic mast and are linked to a generator set,
batteries or any other power generation source.
Current State of the Art
[0003] Currently the need for lighting or additional lighting has led to the widespread
use of stand-alone light towers in many settings, from construction sites to public
events. Given the functionality of these devices, most of them consist of a mast of
a greater or lesser length, typically telescopic, which is deployed to position the
floodlight as high as possible and in this way illuminate a larger area. Examples
of such towers can be found in patents
ES-2630766 "
Device and procedure of monitoring and control in telescopic towers" and
CN202746979 Remotely-controlled movable hydraulic hoisting illumination lamp tower".
[0004] Safe use of a telescopic light, surveillance or communication tower requires guaranteeing
operating safety in all conditions of use of the tower. However, in spite of ensuring
a good design of the telescopic tower, operating safety may be jeopardised by the
conditions in which the tower is installed, the conditions in which the mast is deployed
and other factors external to the installation of the base itself.
[0005] Some of these factors relating to the installation and use of the telescopic tower
directly affect the safety of the equipment. Among these direct factors the following
can be highlighted:
Mechanical factors of the different parts of a telescopic light tower:
- Level of extension of the mast
- Orientation of the floodlights which determine the effective surface area facing the
wind in specific working conditions.
- Deterioration of the quality or strength of the structural elements of the tower.
[0006] Site constraints:
- Characteristics of the terrain, such as ground strength and others
- Slope or gradient of the terrain.
- Presence of objects or obstacles that affect mast extension
[0007] However, other external factors may indirectly affect structural safety and/or cause
the structure to tip over when the tower is in use. Among these factors the following
can be highlighted:
- Ambient factors, wind, rain, ice.
- Conditions of use and handling of the tower, impacts, blows, etc.
- The surface area facing the wind.
[0008] An important characteristic for light, surveillance or communication towers is operation
reliability, for this reason each of the elements that form the mast are dimensioned
to withstand the forces exerted during normal operation of the tower. Due to misuse
or poor maintenance some components can suffer wear and tear, which can cause accidents.
Specifically, the elements that suffer most wear and tear are the elements that drive
the telescopic movement, in particular, steel cables and pulleys. Incorrect functioning
or excessive wear of these elements may cause the breakage of one of the cables, in
which case the telescopic mast would collapse and, as a result, the light, surveillance
or communication devices would fall at an uncontrolled speed, which represents a danger
that could cause a serious accident if an operator is near to the light, surveillance
or communication tower, either during its operation or when performing other types
of work in the area around the said tower.
[0009] Manufacturers have come up with ideas that mainly consist of using mechanical blocking
means, such as pins or bolts, both manual and automatic, between the different segments
that form the tower, as described in patent
ES1211939 "
Load lifting tower with a safety system", but these blocking systems only secure the tower once it is lifted, but not during
the lifting process, which is the most dangerous phase since during it the stability
of the unit depends solely on the cable or cables that lift it.
[0010] Furthermore use of self-braking winches is common, as can be found in patents
ES0145552 "
A winch" and
ES0166981 "
Safety device that acts on a lifting cable in which a winch is raised", but these devices only ensure against a failure of the winch operator or a motor
breakdown, and never protect against the breakage of the lifting cable.
Description of the invention
[0011] To overcome the problem currently existing in relation to safety in the use of light,
surveillance or communication towers, by improving the state of the art, the safety
brake for a telescopic mast of several segments of light, surveillance or communication
towers, which is the object of the invention presented herein, has been devised, which
is a device that can be coupled to a telescopic mast and can be mounted on a light,
surveillance or communication tower, which prevents the total or partial collapse
of the mast due to a malfunction of the latter. This guarantees greater operator safety
during the use of the light, surveillance or communication tower while the mast is
totally or partially deployed. This device comprises one or several retractable reels;
wound on the reel is a belt, cable or rope, finished at its free end in a securing
piece. The retractable reel has means for winding and unwinding the said belt, cable
or rope inside it, and has means for detecting a higher acceleration in the extraction
of the belt, cable or rope than that preset, as well as having means for blocking
and stopping the unwinding of the belt, cable or rope in such a case.
[0012] The retractable reel or reels are firmly attached on the upper part of the external
segment of the mast of the light, surveillance or communication tower and the securing
piece is attached on the lower internal part of the internal segment of the mast,
between which the safety system is going to be installed, the external and internal
segments being telescopically linked, and the belt, cable or rope passing through
the gap between both segments. The belt, cable or rope is guided through at least
one guide piece that prevents the said belt, cable or rope from becoming misaligned
with the telescopic movement that occurs between the two segments of the mast.
[0013] Thus, if there is a breakage in the rope or a sudden collapse of the mast due to
misuse or an oversight in the operating of the light, surveillance or communication
tower, this safety brake detains the fall of the mast segments on which it is installed
and prevents the total or partial collapse of the telescopic mast. Hence, in the event
of a malfunction of the lifting system that involves the sudden collapse of the telescopic
mast, the preceding telescopic movement is blocked, this way preventing the light,
surveillance or communication system from causing injury or damage to the people or
goods located near to the light, surveillance or communication tower.
[0014] The safety brake, linked between a first mast element, preferably more external and
adjacent to a second mast segment, and that are telescopically linked, without excluding
connection between other mast segments, enables the telescopic movement to be blocked
in the event that a given acceleration is detected.
Advantages of the invention
[0015] The safety brake for telescopic mast of several segments of light, surveillance or
communication towers presented herein, affords numerous advantages over the devices
currently available, the most important of these being that it prevents the total
or partial collapse of the mast due to a malfunction of the latter.
[0016] Another important advantage is that it guarantees greater safety for the operator
during the use of the light, surveillance or communication tower, while the mast is
totally or partially deployed.
[0017] A further advantage of this invention is that the safety device enables the telescopic
movement between the first mast element and second mast element to be blocked when
the system descends at an uncontrolled speed, due, for example to a breakage of the
cable.
[0018] Another of the most important advantages worth mentioning is that, in the event of
a malfunction of the lifting device of the mast that involves the sudden collapse
of the telescopic mast, the preceding telescopic movement is blocked, this way preventing
the light, surveillance or communication system from causing injury or damage to the
people or goods located near to the light, surveillance or communication tower.
[0019] In addition, a further advantage is that this safety brake is easily and quickly
adaptable to existing telescopic light, surveillance or communication tower equipment
of any make and origin.
Description of the figures
[0020] To gain a better understanding of the present invention the attached drawing shows
a preferred practical embodiment of a safety brake for a telescopic mast of several
segments of light, surveillance or communication towers.
[0021] In the said drawing, figure -1- shows the safety brake device, unwound in a side
view unwound, and wound in a perspective view.
Figure -2- shows a front view of a light tower according to this invention, in a retracted
position.
Figure -3- shows a front view of the telescopic mast of the light tower, in isolation,
to be able to observe the details described in this invention more clearly.
Figure -4- shows a side view of the cutaway according to the A-A' section of the telescopic
mast of the light tower.
Figure -5- shows a plan view of the light tower in a deployed position.
Figure -6- shows a front view of the light tower in a deployed position.
Figure -7- shows a side view of two of the segments of the telescopic mast of the
light tower in a retracted position.
Figure -8- shows a front view of the detailed cutaway according to section B-B' of
two of the segments of the telescopic mast of the light tower, in a retracted position,
showing the safety brake.
Figure -9- shows a front view of the detailed cutaway according to section C-C' of
two of the segments of the telescopic mast of the light tower, in a retracted position.
Figure -10- shows a side view of two of the segments of the telescopic mast of the
light tower in a deployed position.
Figure -11- shows a front view of the detailed cutaway according to section D-D' of
two of the segments of the telescopic mast of the light tower, in a deployed position,
showing the safety brake.
Preferred embodiment of the invention
[0022] The conformation and characteristics of the invention can be better understood in
the following description that relates to the attached figures, beginning with a general
description of a light, surveillance or communication tower (1).
[0023] In figures 1, 7, 8, 9, and 10 it can be seen that the safety brake for telescopic
mast of several segments, of the type used in masts of light, surveillance or communication
towers (1), comprises at least one retractable reel (14) on which is wound a belt,
cable or rope (15), finished at its free end in a securing piece (16), the retractable
reel (14) having means for winding and unwinding the said belt, cable or rope (15),
having means for detecting a higher acceleration in the extraction of the belt, cable
or rope (15) than that preset, and having means for blocking and stopping the unwinding
the belt, cable or rope (15) in the event of a higher acceleration in the extraction
of the belt, cable or rope (15) than that preset.
[0024] The means for detecting a higher acceleration in the extraction of the belt, cable
or rope (15) than that preset may comprise an inertial accelerometer. The means for
blocking the belt, cable or rope (15) in the event of an acceleration in the extraction
of the belt, cable or rope (15) that is higher that a preset one, may comprise an
inertia brake.
[0025] Preferably a brake device such as that described will be implemented on each tower
(1). It is envisaged that if required, protection can be backed up by incorporating
several brakes per pair of mast segments.
[0026] The light tower (1) normally consists of a base (2), a telescopic mast (3) made up
of a plurality of concentric segments, and a lighting device (4). The said telescopic
mast (3) is anchored to the base (2) by means of the segment located on the lower
part of the telescopic mast (3), commonly the most external one and at the top of
this telescopic mast is the lighting device (4). This lighting device (4) can be formed
by one or more lighting sources. In the case shown as an example in figure 2, the
lighting device (4) consists of 4 LED floodlights, although alternatively a different
number of floodlights, both LED, adjustable or not, and metal halide or halogen, can
be used. If the tower (1) is a surveillance or communication tower, several cameras
or aerials can be fitted at the same time.
[0027] As can be seen in figures 8, 9 and 11, the retractable reel (14) is firmly attached
on the upper external part of an external segment (8) of the telescopic mast (3) of
the light, surveillance or communication tower (1) and the securing piece (16) is
attached on the lower internal part of an internal segment (9) of the telescopic mast
(3), between which the safety system is going to be installed, the external segment
(8) and the internal segment (9) being telescopically linked and the belt, cable or
rope (15) passing through the gap between both segments. The belt, cable or rope (15)
is guided through at least one guide piece (17) that prevents the said belt, cable
or rope (15) from becoming misaligned with the telescopic movement that occurs between
both segments of the mast. This guide piece (17) for the belt, cable or rope (15)
can be static or dynamic with circular movement, such as for example a pulley.
[0028] The external segment (8) and internal segment (9) can be any of those that form the
telescopic mast (3), provided that one is always internal to the other inside the
telescopic mechanism. In a preferred embodiment the external segment (8) is the lower
segment, once deployed, of the telescopic mast (3) and the internal segment (9) is
the one following the external segment (8). In an alternative embodiment the external
segment (8) is the lower segment, once deployed, of the telescopic mast (3), and the
internal segment (9) is the upper segment, once deployed, of the telescopic mast (3).
[0029] Thus, if there is a breakage of the rope (6) or a sudden collapse of the mast due
to misuse or an oversight in the operating of the light tower, this safety brake (13)
detains the fall of the mast segments on which it is installed and prevents the total
or partial collapse of the telescopic mast (3). The safety brake (13) allows the telescopic
movement to be blocked if a given acceleration is detected.
[0030] Figure 2 shows an illustration of an example of a light, surveillance or communication
tower (1) according to the present invention, in a retracted position. This illustration
does not limit the possibility of other light tower and/or mast configurations.
[0031] Figures 3 and 4 show the telescopic mast (3) of the light, surveillance or communication
tower (1). This telescopic mast (3) consists of a lifting device consisting of a winch
(5), in this case manual, although it could be replaced by similar devices such as,
for example, electric winches or hydraulic systems, attached to the first mast element
(8); at least one rope (6), normally steel, and at least one pulley (7). The illustration
shows a mast consisting of 4 ropes and 4 pulleys, however, to facilitate the understanding
of the safety brake, its application will be shown only on the first two segments
(8) and (9) of the mast, although this safety brake is applicable to any two segments
of the mast linked together telescopically. It is envisaged that the safety brake
can be installed between any segment of the telescopic mast (3) on which the retractable
reel (14) is fitted, and its immediate interior, in telescopic order, on which the
securing piece (16) is fitted.
[0032] The winch (5) acts on the first of the ropes (6) which is linked, by means of the
pulley (7), to the lower and internal part of the second mast segment (9), which is
immediately interior to the first mast segment (8), both belonging to the telescopic
mast (3) unit.
[0033] By means of the action of the winch (5), the rope (6) is tightened, causing the ascent
of the second mast segment (9) in regard to the first mast segment (8), in a telescopic
movement. By means of the rest of the ropes (10), the rest of the mast segments elevate
at the same time as the first mast element on which the winch (5) acts, in a telescopic
movement until the required height is reached. To operate the winch (5) it is usually
necessary for an operator to manually operate it in the vicinity of the light, surveillance
or communication tower (1), although there are also automatic and telematic procedures.
[0034] Both the ropes (6) and pulleys (7), and the rest of the ropes and pulleys of the
machine, are designed and dimensioned to withstand, except in the case of abnormal
functioning, the tensions that occur in the mast segments during their operation.
During lifting of the telescopic mast these ropes and pulleys undergo greater stress
than during normal operation of the light, surveillance or communication tower (1),
making this phase quite critical due to the presence of at least one operator near
to the base (2) of the light, surveillance or communication tower (1)
[0035] Figures 5 and 6 show the tower in its fully deployed position. For greater safety
and stability, the base (2) is supported preferably by stabilisers (11), the number
of which can vary depending on the need to increase the area on which the tower is
supported, the said stabilisers allowing the tower to be levelled even on uneven terrain.
Frequently, the base (2) includes auxiliary systems for transportation, such as housings
for lifting using forklifts or similar, lifting eyes or housings for lifting and wheels.
Furthermore, preferably the base (2) has electrical connections that enable the lighting
system (4) to light up. The said connections may be formed by a generator, batteries,
external power supply connections, etc. The electrical connection between the base
(2) and the lighting system 1.3 normally consists of a coiled cable that can stretch
and contract depending on the height of the lighting system (4), but it can also be,
including a wide variety of options, an internal mast cable or a cable that winds
up with a reel. In addition, the base (2) comprises all of the devices required for
the operation of the telescopic mast and other elements that the operator is not always
aware of or does not know it has.
[0036] Figures 7, 8, and 9 show a cutaway of the upper and lower part of two segments of
the telescopic mast (3) in its retracted position, showing an example of the installation
of the safety brake (13), with the protective housing removed for a better view, between
the mast segment (8) and the mast segment (9), which are linked together telescopically.
[0037] Figures 9 and 11 show the cutaway of the upper and lower part of two segments of
the telescopic mast (3) in its deployed position, showing an example of the installation
of the safety system, with its protective housing eliminated for a better view, between
the internal segment (9) of the telescopic mast (3) and the external segment (8) of
the telescopic mast, which are linked together telescopically.
[0038] This example of the installation of the safety brake (13) that is shown in the figures
has been installed between the first two elements of the telescopic mast (3), which
prevents the collapse of the first moving segment (9) of the telescopic mast. This
situation is the most restrictive since this first cable is that which supports most
tension in the unit and thus is the one most exposed to breakage. Moreover, in the
event of other mast cables breaking, the collapse would be partial, which would not
entail as much risk for the operator in the event of a collapse of the mast. Obviously,
it is possible to install this device between any of the segments of the telescopic
mast (3).
[0039] A person skilled in the art will easily comprehend that the characteristics of different
embodiments can be combined with the characteristics of other possible embodiments,
provided that the combination is technically possible.
[0040] All the information referring to examples or embodiments form part of the description
of the invention.
1. Safety brake for telescopic mast of several segments, of the type used in masts of
light, surveillance or communication towers, characterised in that it comprises at least one retractable reel (14), firmly attached on the upper part
of an external segment (8) of the telescopic mast (3) of the light, surveillance or
communication tower (1), on which is wound a belt, cable or rope (15), finished at
its free end in a securing piece (16), firmly attached on the lower internal part
of an internal segment (9) of the telescopic mast (3), the belt, cable or rope (15)
passing through the gap between both segments, the retractable reel (14) having means
for winding and unwinding the said belt, cable or rope (15), having means for detecting
a higher acceleration in the extraction of the belt, cable or rope (15) than that
preset, and having means for blocking the belt, cable or rope (15) in the event of
a higher acceleration in the extraction of the belt, cable or rope (15) than that
preset.
2. Safety brake for telescopic mast of several segments, according to the preceding claim,
wherein the external segment (8) is the lower segment,once deployed, of the telescopic mast
(3), and the internal segment (9) is the one following the external segment (8).
3. Safety brake for telescopic mast of several segments, according to claim 1, wherein the external segment (8) is the lower segment, once deployed, of the telescopic mast
(3), and the internal segment (9) is the upper segment, once deployed, of the telescopic
mast (3).
4. Safety brake for telescopic mast of several segments, according to the preceding claims
wherein the belt, cable or rope (15) is guided through at least one guide piece (17).
5. Safety brake for telescopic mast of several segments, according to claim 4, wherein the guide piece (17) for the belt, cable or rope (15) is static.
6. Safety brake for telescopic mast of several segments, according to claim 4, wherein the guide piece (17) for the belt, cable or rope (15) is a pulley or roller.
7. Safety brake for telescopic mast of several segments, according to the preceding claims,
wherein the means for detecting a higher acceleration in the extraction of the belt, cable
or rope (15) than that preset, comprises an inertial accelerometer.
8. Safety brake for telescopic mast of several segments, according to the preceding claims,
wherein the means for blocking the belt, cable or rope (15) in the event of a higher acceleration
in the extraction of the belt, cable or rope (15) than that preset, comprises an inertia
brake.
9. Safety brake for telescopic mast of several segments, according to the preceding claims,wherein
the brake can be mounted on any of the segments of the telescopic mast (3), on which
the retractable reel (14) is fitted, and its immediate interior, in telescopic order,
on which the securing piece (16) is fitted.
10. Safety brake for mast of light, surveillance or communication tower, according to
the preceding claims wherein the number of brakes per pair of segments can be increased to reinforce safety.