WO2022229483A1

WO2022229483A1 - Lifting tower

Info

Publication number: WO2022229483A1
Application number: PCT/ES2022/070244
Authority: WO
Inventors: Jacob GARCÍA PALAU
Original assignee: Equipson, S.A.
Priority date: 2021-04-30
Filing date: 2022-04-21
Publication date: 2022-11-03
Also published as: ES1269469U; ES1269469Y

Abstract

Disclosed is a lifting tower comprising a fixed bar (1) and at least one sliding bar (2a, 2b), parallel to the fixed bar (1), wherein the sliding bar (2a, 2b) is designed to move longitudinally with respect to the fixed bar (1) by means of a pulley system comprising a first movable pulley (3b), connected to the sliding bar (2a, 2b). The first movable pulley (3b) is designed to move longitudinally with respect to the fixed bar (1), reciprocally with the sliding bar (2a, 2b), when an actuation device (5) is operated, the second end of a cable (4) being immovable and rigidly joined to the fixed bar (1) of the lifting tower, such that a first fixed pulley (3a) and the first movable pulley (3b) form a hoist.

Description

LIFTING TOWER

DESCRIPTION

OBJECT OF THE INVENTION

The following invention relates to a lifting tower, comprising a new pulley mechanism, configured to lift and support loads at one end while it remains supported on a fixed support, in such a way that said new mechanism allows the movement of the sliding bars. that make up the tower as well as the load that the tower supports with less effort than that required in the mechanisms of existing lifting towers.

In this way, the purpose of the device is to provide the lifting towers with a multiplier effect in relation to the energy entering the tower and the displacement produced in it, providing, at the same time, greater smoothness when raising the mechanism. .

The invention is within the technical field of the load lifting mechanisms sector, more specifically, in lifting devices specially adapted for special purposes, which come into contact with the ground to support, lift or maneuver loads.

BACKGROUND OF THE INVENTION

Currently, lifting towers are widely known on the market, consisting of devices that allow lifting and/or supporting loads at a specific height. Said towers mostly have bars arranged in a vertical orientation and are configured to unfold, extending all the bars they comprise, until reaching a desired height. The displacement in the longitudinal direction of the bars is normally produced by the effect of a system of pulleys connected by a rope or cable, in such a way that when pulling one end of said cable, the displacement of the bars occurs, extending them, and when releasing said cable, the folding of the tower takes place.

Although there are different means of lifting, most of the lifting towers on the market are configured with a simple mechanism of pulleys that lift loads without providing mechanical advantage. In other words, the lifting towers obtain all their mechanical advantage from the transmission ratio provided by the winch, which transforms the circular movement into a linear movement.

Said pulley mechanism consists of taking the cable from the capstan, to which it is connected at its first end, to the bar on which the load rests, to which the second end is connected, passing from bar to bar by means of pulleys, whose Its function consists solely in redirecting the force provided by the user in activating the winch, so that each bar lifts the following ones.

As one of the ends of the cable is integral with the load, all the force must be provided from the other end of the cable, that is, from the winch.

This system can be seen in figures 1A-1C, where when unfolding the bars, the mechanism can be simplified as a simple pulley (the one on the mast) pulling a mass (which corresponds to the bars, the load supported on said bars and the two pulleys located on the sliding bars).

THEORETICAL FRAMEWORK

It is known that pulley systems can provide a mechanical advantage in moving and lifting objects. The following is the physical relationship that allows lifting tower pulleys to be configured to reduce the effort required to lift the load while reducing reaction forces on the rope and pulley bearings.

A lifting tower is a device capable of transforming kinetic energy provided by the user, from the winch, into an increase in potential energy of a load placed on it. An input energy of the system (Ei) and an output energy (Em) can then be defined as follows:

Ei [J ] = T [N m] Da [1]

Em [J ] = M [kg] g [m/s ² ] Ad [m] [2]

Where:

T: Torque provided at the winch handle.

M: Mass of the resulting load to be lifted (also including the mass of the bars that are being displaced). g: Value of gravity on the earth's surface (9.81 m/s ² ).

Da: Number of revolutions that the user gives to the winch handle.

Ad: Displacement of the resulting load to be lifted (also including the mass of the bars being displaced).

There are many pulley configurations but they are all based on the same principle: Knowing that energy is equal to force times displacement (E = F Ad) and that it is also constant throughout the transmission chain (by the law of conservation of energy), it is possible to produce the same energy at the output of the system by exerting less force on the input if the displacement at the input is increased by the same amount as the force is reduced. That way:

Ei = Em

T Da = M g Ad T/r Da r = M g Ad

T' Da' = M g Ad [3]

Where: r: Transmission ratio of the system.

T': New torque to exert (T' = T/r).

Da': New number of necessary revolutions (Da' = Da r).

Under this relationship, hoists work, which are devices made up of two or more pulleys and a rope, cable or chain that alternately passes through the various grooves of each of these pulleys. These devices are used to lift or move a load with a great mechanical advantage, since it requires applying a much lower force than the weight to be moved by applying a larger input displacement.

In other words, the hoists achieve this transmission effect through the use of mobile pulleys and the positioning of the load at one or more intermediate points of the cable, understanding that a mobile pulley is a pulley whose position varies in relation to the immobile fixed pulleys. , and through which the cable slides. If the pulley moves, but there is no slip with the cable, the pulley is simplifyable to a mass on the cable and does not contribute to the gear ratio. Through this ratio of input and output energies, the drawbacks of the current systems used in lifting towers can be resolved, reducing the force necessary to move a load the same distance in height.

DESCRIPTION OF THE INVENTION

From the theoretical framework section, it can be concluded that the appropriate lifting tower to solve the problems indicated in the background, and that allows reducing the force necessary to move objects, must include at least one mobile pulley, and that the load applied to said lifting tower must rest on one or more intermediate points of the cable in order to reduce the input torque. It must also have a fixed point on the tower that will serve as a reference to determine if a pulley is fixed or mobile, as well as to establish anchor points for fixed or cable pulleys.

In this way, said lifting tower comprises:

- a fixed bar and at least one sliding bar, parallel to the fixed bar, where said sliding bar is configured to move in a longitudinal direction with respect to the fixed bar by means of a pulley system, the longitudinal direction being the direction of the axis of both bars, as they are parallel;

- the pulley system comprising at least one first fixed pulley assembled to the fixed bar and a cable configured to slide on pulleys of the pulley system. Cable is defined as a flexible element that allows communication between pulleys, and can be a metal cord, a rope or a chain that allows the described operation.

- a drive device for the pulley system attached to a first end of the cable, where said drive device is configured to pull said first end of the cable by picking it up, being able to wind it on an axis, moving the, at least one, sliding bar with respect to of the fixed bar in the longitudinal direction of unfolding, extending the lifting tower; and to release the collected cable, freeing it, moving the sliding bar, with respect to the fixed bar in the same longitudinal direction, in the opposite direction of folding, collecting the lifting tower; Y

- a means of support or fastening to the outside of the lifting tower, such as a floor or frame, configured to support said lifting tower; where the pulley system comprises a first mobile pulley, assembled to the at least one sliding bar, connected as the pulleys are supported, that is, in a way that allows the support of the load they support but also the rotation of the pulley on itself, said movable pulley configured to move in the longitudinal direction with respect to the fixed bar reciprocally to said sliding bar, when the drive device is actuated; where the second end of the cable is stationary, that is, it is fixed and rigidly attached to the fixed bar of the lifting tower; and where the first fixed pulley and the first mobile pulley comprise a hoist. In this way, both the second end of the cable and the fixed bar do not move, and they can be directly connected to each other, or through other parts of the tower itself or external parts.

The defined hoist between the fixed pulley and the mobile pulley has a transmission ratio close to 2, that is to say, practically half the torque and twice the turns are required to raise the load supported by the tower.

In one embodiment, the lifting tower comprises a first and a second slider bar parallel to the fixed bar, configured to move in a longitudinal direction with respect to the fixed bar, where the first slider bar is configured to move in the same longitudinal direction with respect to the second slider bar; where the first mobile pulley is assembled to the first sliding bar, configured to move in the longitudinal direction with respect to the second sliding bar reciprocally to the first sliding bar; where the second sliding bar is assembled to at least one second mobile pulley, included in the pulley system, where said second mobile pulley is configured to move in the longitudinal direction with respect to the fixed bar reciprocally to the second sliding bar ; and where the first fixed pulley and the second mobile pulley make up a hoist. In this way, the transmission ratio of this second hoist is also close to 2, so that, whether the first or the second lifting tower is being raised, the effort required to do so will be half of what is necessary with the existing towers that they do not have moving pulleys, and the number of turns of the fixed pulley will be doubled.

In one embodiment, the pulley system comprises:

- a third, a fourth, a fifth mobile pulley assembled to the second sliding bar, configured to move in the longitudinal direction with respect to the fixed bar when actuating the actuating device. These pulleys are supported on said second sliding bar, allowing the rotation on themselves as well as the transmission of loads.

In another embodiment, different from the previous one, the pulley system comprises:

- a second, a third, a fourth fixed pulley, assembled to the fixed bar, configured to support and distribute the cable through the lifting tower.

In addition to these embodiments of pulleys, the lifting tower can include other configurations with as many sliding bars as required, each of them having at least one mobile pulley and as many other fixed or mobile pulleys as required for the operation described in the previous realizations.

In one embodiment, the drive device comprises a winch rigidly connected to the fixed bar. In a more specific embodiment, said capstan comprises a motor configured to pick up the cable and wind it on a shaft rotated by said motor. In other embodiments, the winch comprises a crank for manual actuation.

In one embodiment, the outer support means comprises a plurality of legs connected by an articulated joint to the fixed bar, said legs being configured to lock, being rigidly fixed to said fixed bar. These legs provide stability to the lift tower when it is in use.

In one embodiment, the bars are hollow and telescopically connected. In other words, the bars are inserted from the smallest to the largest section, with the fixed bar on the outside.

In one embodiment, the bars are rectangular prismatic. In other embodiments, the bars can have other sections such as circular, but the rectangular prismatic shape allows a better distribution and connection of the pulleys.

In one embodiment, the longitudinal direction in which the at least one slider is configured to move relative to the fixed bar is a vertical direction. In other words, the elevation of the elevation tower is completely vertical, and in other embodiments it may include some inclination. In one embodiment, a first end of the first slide bar comprises a fastening means configured to be fixed to a load to be lifted by the lifting tower. In this way, when lifting, the load resting on the slider bar is well secured to the lifting tower.

In one embodiment, the lifting tower comprises a first locking means configured to limit the displacement of the first slider bar with respect to the second slider bar, and a second locking means configured to limit the displacement of the second slider bar relative to the slider bar. fixed. In this way, when the lifting of the load supported by the sliding bars occurs, the cable has to support all said load, but once the tower is deployed, it is the bars that support an axial force of the load applied in the end of the sliding bar, being possible thanks to said locking means, which may comprise pins or similar elements.

In the event that the tower comprises more sliding bars, each of them would have a blocking means to prevent the entire load from being supported on the cable instead of on the bars.

BRIEF DESCRIPTION OF THE FIGURES

To complement the description that will be made below, and in order to help a better understanding of the characteristics of the invention, a set of plans is attached to this descriptive memory, in whose figures in an illustrative and non-limiting manner , the most characteristic details of the invention are represented.

Figure 1A-1C. It shows three diagrams of an arrangement of bars and pulleys of an existing lifting tower in the state of the art, where the second end of the cable is rigidly connected to the first sliding bar. In figure 1A the tower is shown with the bars collected, in 1B the first sliding bar is shown raised with respect to the rest after having pulled the winch cable, and in figure 1C the two sliding bars are shown raised with respect to the fixed one. .

Figure 2A-2C. It shows three diagrams of an arrangement of bars and pulleys of a lifting tower, following the example of figures 1A-1C, but in this case, being this lifting tower defined according to claim 2, comprising a fixed bar, and two sliding bars arranged telescopically, where said tower comprises a first mobile pulley connected to the first sliding bar and a second mobile pulley connected to the second sliding bar. This scheme is represented in two dimensions, since it allows to visualize in a simple way the operation of the claimed tower, but the position of the pulleys can be different, some of them being located concentrically, being able to dispense with some of them depending on their position .

Figure 3. Shows a perspective view of a lifting tower that includes a system of bars and pulleys like the one shown in figure 1B, being able to see all the bars of the tower, the support or external support, the winch, the blocking means and the cable connecting the pulleys.

Figure 4. Shows a perspective view of the lifting tower shown in figure 2, without the bars or the blocking means, allowing the distribution of the pulleys and the cable inside the tower to be observed.

Figure 5. Shows a perspective view of the lifting tower similar to the one shown in figure 3, but from a rear view, and with a magnification that allows the internal components of the tower to be more easily visualized.

Figures 6A-6B. They show an elevation view and another in profile of the distribution of the lifting tower pulley system of figures 2 to 4, also showing the cable that connects said pulleys, as well as the winch.

DESCRIPTION OF A PREFERRED EMBODIMENT

Considering the numbering adopted in the figures, the lifting tower of the preferred embodiment comprises a pulley mechanism or system that has a return line that allows multiplying the input traction force to said tower with respect to existing systems or mechanisms, in exchange for a greater number of revolutions to be applied to the winch on which the input energy is applied, as can be seen in the diagram of figures 2A-2C.

Figures 1a-1C show a diagram of an existing elevation tower in the state of the art that comprises an arrangement of three parallel bars (1, 2a, 2b), one of them being a fixed bar (1) and the other two sliding bars (2a, 2b) relative to the fixed bar (1). The diagram also shows the lifting tower pulley system, this system being the one used in the existing lifting towers on the market, where there is no multiplication of the input force, except for that generated by the winch itself , but a direct transformation from circular to linear motion.

With said diagram of figures 1A-1C, it is possible to observe the distribution of the cable (4) in the pulley system, so that a first end of said cable (4) is located outside the fixed bar (1) , so that it can be connected to a winch or any other drive device (5), while the second end is rigidly fixed to a lower end part of the first sliding bar (2a), so that it will move reciprocally . In this way and with this configuration, the length of the cable (4) extracted from the lifting tower, that is, the one picked up by the winch, is the same length that the first sliding bar (2a) moves with respect to the fixed bar (1), without there being any multiplier effect of the input force coming from the cable.

Once said first sliding bar (2a) has been vertically displaced the full length possible by pulling the first end of the cable (4), as shown in Figure 1B, if you continue to pull that same end, the displacement occurs. of the first (2a) and the second sliding bar (2b), jointly, with respect to the fixed bar (1), as shown in figure 1C. In that situation, both the first slider (2a) and the second slider (2b) move in the vertical direction at the same time, so that the transmission ratio remains 1, since the first end of the cable (4 ) is supported by a first fixed pulley (3a), but the second end moves vertically as it is attached to the first sliding bar (2a). In this way, the length of the cable (4) extracted from the fixed bar (1) is the same as the length displaced in height by the sliding bars (2a, 2b).

In this way, it can be defined that an object of the invention is that all the mobile bars of the lifting tower have a multiplying effect, as shown in figures 2A-2C.

The solution adopted in the preferred embodiment is shown in the diagram of the figures 2A-2C, where three bars (1, 2a, 2b) are also shown, the widest being the fixed bar (1) and the first (2a) and the second sliding bar (2b) located inside it ; the cable (4) and the pulley system adopted. In this embodiment, the first end of the cable (4) is also located in an outer upper end part of the fixed bar (1), so that it can be connected to a winch or an actuating device (5), but the second end of the cable (4) is not rigidly connected to a sliding bar (2a, 2b) but is rigidly connected, also to an upper end part of the fixed bar (1).

In the diagram of figures 2A-2C it can be seen how the first end of the cable (4) is directed from a first fixed pulley (3a), assembled to an upper part of the fixed bar (1), to a second mobile pulley (3c), assembled to a lower part of the second sliding bar (2b), to then go to a fourth mobile pulley (3e), assembled to an upper part of the same second sliding bar (2b), to then go to the first mobile pulley (3b), assembled to a lower end part of the first sliding bar (2a). From that point, the cable travels in reverse, heading for a third mobile pulley (3d), assembled at the top of the second sliding bar (2b), to then head for a fifth mobile pulley (3f-3g). , assembled to a lower part of the same second sliding bar (2b). From this fifth mobile pulley (3f-3g), the cable (4) ends at its second end rigidly connected to an upper end part of the fixed bar (1).

With this distribution of pulleys, where the first fixed pulley (3a) forms a hoist with the first (3b) and with the second mobile pulley (3c), the multiplier effect is achieved for each sliding bar (2a, 2b).

In addition to this configuration described, the lifting tower can include other configurations that also generate the multiplier effect, provided that each sliding bar (2a, 2b) corresponds to at least one mobile pulley (3b, 3c).

This configuration also allows the lifting tower, in addition to comprising two sliding bars (2a, 2b), to comprise more bars; as many as are considered necessary to lift a load, a vertical distance. In addition, the position of the pulleys can be altered, since figure 1B is a two-dimensional diagram that allows visualizing the operation of the tower, but having some of said pulleys in different transverse positions, the use of necessary pulleys can be reduced.

In the same way, if necessary, and if there is sufficient space and a good arrangement of pulleys inside the lifting tower, the transmission ratio can be increased by increasing the number of times that the cable (4) is directed from the fixed bar (1) to the sliding bar (2a, 2b) on which the load rests, and vice versa.

Figure 3 shows a lifting tower comprising a configuration of bars (1, 2a, 2b) and pulleys (3a-3g) as defined from the diagram of figures 2A-2C, being able to observe in this case that the actuation device (5) comprises a winch connected to the first end of the cable (4), and that the external support means (6) comprises four legs connected by means of an articulated joint to the fixed bar (1), in such a way that said legs can be locked in a support position, distributing the load supported by the tower over a larger surface, preventing the tower from tilting. Also, in said figure 3, the first (7a) and the second locking means (7b) are shown, which are elements that comprise pins or stops that allow the movement of the sliding bars (2a, 2b) to be blocked.

Figures 4 to 6A and 6B show the arrangement of the pulley system and the cable (4) inside the lifting tower of figure 3. In these figures it can be seen how some of the pulleys can be positioned. so that the space occupied is the minimum possible.

It can also be seen how the two pulleys shown and defined as the fifth mobile pulley (3f-3g) of the diagram of figures 2A-2C are simplified into a single mobile pulley (3f-3g) in figures 4 to 6A and 6B, since that with a single pulley arranged parallel to the second mobile pulley (3c) is sufficient for the correct operation of the lifting tower.

Claims

1.-Lifting tower comprising:

- a fixed bar (1) and at least one sliding bar (2a, 2b), parallel to the fixed bar (1), where said sliding bar (2a, 2b) is configured to move in a longitudinal direction with respect to the fixed bar (1) by a pulley system;

- the pulley system comprising at least one first fixed pulley (3a) assembled to the fixed bar (1) and a cable (4) configured to slide on pulleys (3a-3g) of the pulley system;

- a drive device (5) of the pulley system attached to a first end of the cable (4), where said drive device (5) is configured to pull said first end of the cable (4), moving the at least one sliding bar (2a, 2b) with respect to the fixed bar (1) in the longitudinal direction of unfolding, extending the lifting tower; and to release the cable (4), freeing it, moving the sliding bar (2a, 2b) with respect to the fixed bar (1) in the same direction, in the opposite direction of folding, picking up the lifting tower;

- an external support means (6) configured to support the lifting tower; characterized in that the pulley system comprises a first mobile pulley (3b), assembled to the at least one sliding bar (2a, 2b), configured to move in the longitudinal direction with respect to the fixed bar (1) reciprocally to said slide bar (2a, 2b) when actuating the driving device (5); where the second end of the cable (4) is stationary, and is rigidly attached to the fixed bar (1) of the lifting tower; and where the first fixed pulley (3a) and the first mobile pulley (3b) comprise a hoist.

2. Lifting tower, according to the preceding claim, comprising a first (2a) and a second sliding bar (2b) parallel to the fixed bar (1), configured to move in a longitudinal direction with respect to the fixed bar (1) , where the first slider bar (2a) is configured to move in the same longitudinal direction with respect to the second slider bar (2b); where the first mobile pulley (3b) is assembled to the first sliding bar (2a), configured to move in the longitudinal direction with respect to the second sliding bar (2b) reciprocally to the first sliding bar (2a); where the second slider (2b) is assembled to at least one second mobile pulley (3c), included in the pulley system, where said second mobile pulley (3c) is configured to move in the longitudinal direction with respect to the fixed bar (1) reciprocally to the second bar slider (2b); and where the first fixed pulley (3a) and the second mobile pulley (3c) make up a hoist.

3. Lifting tower, according to the preceding claim, where the pulley system comprises:

- a third (3d), a fourth (3e) and a fifth mobile pulley (3f-3g) assembled to the second sliding bar (2b), configured to move in the longitudinal direction with respect to the fixed bar (1) when activating the drive device (5).

4 - Lifting tower, according to claim 2, wherein the pulley system comprises:

- a second (3d), a third (3e) and a fourth fixed pulley (3f-3g), assembled to the fixed bar (1), configured to support and distribute the cable (4) through the lifting tower.

5. Lifting tower, according to any of the preceding claims, where the drive device (5) comprises a winch rigidly connected to the fixed bar (1).

6. Lifting tower, according to the preceding claim, where the winch comprises a motor.

7. Lifting tower, according to any of the preceding claims, wherein the external support means (6) comprises a plurality of legs connected by an articulated joint to the fixed bar (1), said legs being configured to be locked, rigidly fixed to said fixed bar (1).

8. Lifting tower, according to any of the preceding claims, where the bars (1, 2a, 2b) are hollow and are telescopically connected.

9. Lifting tower, according to any of the preceding claims, where the bars (1, 2a, 2b) are rectangular prismatic.

10. Lifting tower, according to any of the preceding claims, wherein the longitudinal direction in which the at least one sliding bar (2a, 2b) is configured to move with respect to the fixed bar (1), is a vertical direction.

11.- Lifting tower, according to claim 2 and any of the preceding claims, wherein a first end of the first sliding bar (2a) comprises a fastening means configured to be fixed to a load to be lifted by the lifting tower.

12.- Lifting tower, according to claim 2 and any of the preceding claims, comprising a first blocking means (7a) configured to limit the displacement of the first sliding bar (2a) with respect to the second sliding bar (2b), and a second blocking means (7b) configured to limit the displacement of the second sliding bar (2b) with respect to the fixed bar (1).