EP2085350A1 - Winding lifting system - Google Patents

Abstract

The system has a motorized and movement controlled reel (2) receiving a vertical inflated structure i.e. inflated column (3). The structure has a fixation unit in its lower part (3i). An anchoring unit is provided in an upper part (3s) of the structure to anchor an object e.g. equipment (8) such as antenna, to be displaced. A fluid injection device injects a low pressure fluid e.g. water, in the structure using an inflated tube (6) and a pressure regulation system (5). A guiding device (4) guides the structure, where the structure is made of coated polyester fibers and elastomer coating. An independent claim is also included for a method for permitting displacement of an object.

Description

The invention relates to a system for lifting an object or a load. It is, for example, used for the vertical deployment of equipment such as antenna, camera, lighting system or any other system.

• L'élévation verticale d'une charge en utilisant la pression interne de la structure réalisée en composite souple,
• La réduction de la hauteur du système en configuration « mât rétracté »,
• Des problèmes de cinématiques de déploiement : le déploiement vertical continu sans à-coup.

A problem currently present in our society is to be able to raise a load or equipment from a first position in elevation to a second position or in a final position. One of the objectives of the invention is therefore to raise equipment at a height of the ground or a surface. The problems that may arise are as follows; problems of mechanical stability of the structure related to the load to be raised such as the problem of deflection, buckling, vibrations; problems of implementation of the elevation of the load or the equipment, such as deployment times of the mast and the necessary equipment as well as the number of operators, the necessary means, the repeatability. It is also necessary to take into account the mass of the structure equipped with its load, the bulk of the latter not deployed to integrate on a carrier. During this deployment and once the mast is deployed, it is necessary to take into account the resistance to severe environmental constraints. During its use, it is also possible to transfer the structure from one place to another, changing vehicles or platforms of use without integration operations or specific editing. The deployment of the mast, once docked to the ground (vehicle or platform), is automatic. There is no manual interlocking operation of mast elements.
The areas known to the applicant as being the closest are for example the inflatable antennas known from the prior art.
There are also inflatable devices serving as a support for visual information, inflatable advertising structures (not waterproof), games inflatable boats, inflatable tubes for construction devices, inflatable meshes for space applications involving low levels of internal pressures.
In the field of masts, it is also possible to mention interlocking pneumatic masts made of rigid elements made of aluminum or composite type material. There are also telescopic masts, hydraulic or electric. These masts provide functionality equivalent to the mast structure according to the invention, however, they require room for storage. For example, the retracted height is important because of the use of rigid materials. In contrast, in the structure of the present patent application, the ratio "retracted mast height" of the existing technologies and the proposed solution is approximately of the order of 2, which is clearly preferable to the knowledge of the Applicant.
In summary, the disadvantages resulting from the various devices of the prior art are generally the following: integration operations in a defined vehicle necessary. There is no interchangeability possible once integration is done. The tightness of some existing inflatable structures is not reliable enough. These structures are then based on a permanent inflation system throughout their operating phase. This explains that this type of structure does not usually have its own stiffness. Another disadvantage is that because the internal pressure level is low (a few mbar), folds of the structure may appear, the latter being very deformable. It is difficult then to speak of mechanical rigidity.
In some cases of supporting structure, there is a high level of pressure. In general, the structures of the prior art do not take into account the following problems:

• The vertical elevation of a load using the internal pressure of the structure made of flexible composite,
• Reducing the height of the system in "retracted mast" configuration,
• Deployment kinematics issues: the vertical deployment continues smoothly.

The object of the invention is based on a new approach which is based in particular on the winding of an inflatable column around a drum.

• o un touret contrôlé en mouvement, ledit touret recevant une structure gonflable, le touret étant en liaison avec un système de freinage,
• o ladite structure gonflable étant pourvue dans sa partie inférieure de moyens de fixation sur ledit touret et dans sa partie supérieure de moyens d'accrochage de l'objet à déplacer,
• o un dispositif d'injection de fluide et une valve de surpression au niveau de la partie supérieure dans ladite structure gonflable, par l'intermédiaire d'un tuyau et d'un moyen de régulation de pression,
• o un moyen de guidage de ladite structure gonflable.

La structure gonflable est une colonne gonflable et le déplacement est un déplacement en élévation.
Le fluide est, par exemple, choisi parmi l'un des éléments suivants : l'air, l'eau, un gaz.
Le moyen de motorisation peut être un moteur permettant un déplacement continu du touret.
La structure gonflable est fabriquée dans l'un des matériaux suivants : des fibres de polyester enduites, l'enduction étant réalisée à partir d'élastomères. La structure gonflable peut être pourvue de moyens permettant l'attache de moyens d'ancrage afin de la stabiliser.
L'invention concerne aussi un procédé permettant de déplacer un objet disposé initialement dans une première position dans une deuxième position au moyen d'une structure gonflable enroulable sur un touret motorisé comportant un axe et contrôlé en mouvement caractérisé en ce qu'il comporte au moins les étapes suivantes :

• la structure étant en position enroulée autour du touret, pour l'étape de déroulement de ladite structure:
  • injecter un fluide dans la partie supérieure de ladite structure gonflable à une valeur de pression choisie en fonction des conditions externes à la structure et des caractéristiques de l'objet à déplacer en guidant ladite colonne en sortie du touret, entre le touret et le caisson dans lequel est disposée la structure gonflable et le touret,
  • réguler la pression du fluide injectée de façon à maintenir un niveau de pression afin de conserver la structure gonflable dans la position finale,
  • freiner de façon constante l'axe du touret de façon à ce que ce soient les efforts dus à la pressurisation de la structure qui permettent le deploiement
  pour l'étape d'enroulement de la structure gonflable,
  • mettre en route le touret dans le sens d'enroulement, en exerçant des efforts supérieurs au moins à la tension présente dans la structure gonflable afin que ladite structure s'enroule de façon continue créant une surpression dans la partie supérieure de la colonne,
  • évacuer le fluide par la partie supérieure de la structure au moyen d'une valve de surpression.

On utilise par exemple comme fluide de l'air, de l'eau ou un gaz.
Le déploiement de la structure s'effectue sensiblement de manière verticale..The invention makes it possible to move an object initially arranged in a first position to a second position, characterized in that it comprises in combination at least the following elements:

• a controlled drum in motion, said drum receiving an inflatable structure, the drum being in connection with a braking system,
• o said inflatable structure being provided in its lower part with fastening means on said drum and in its upper part hooking means of the object to be moved,
• a fluid injection device and an overpressure valve at the upper part in said inflatable structure, via a pipe and a pressure regulating means,
• a means for guiding said inflatable structure.

The inflatable structure is an inflatable column and the displacement is a displacement in elevation.
The fluid is, for example, selected from one of the following: air, water, a gas.
The motorization means may be a motor allowing a continuous movement of the drum.
The inflatable structure is manufactured in one of the following materials: coated polyester fibers, the coating being made from elastomers. The inflatable structure may be provided with means for attaching anchoring means to stabilize it.
The invention also relates to a method for moving an object initially disposed in a first position in a second position by means of an inflatable structure windable on a motorized reel having an axis and controlled in motion characterized in that it comprises at least the following steps:

• the structure being in position wound around the drum, for the unwinding step of said structure:
  • injecting a fluid into the upper part of said inflatable structure at a pressure value chosen according to the conditions external to the structure and the characteristics of the object to be moved by guiding said column at the exit of the drum, between the drum and the casing in which is arranged the inflatable structure and the drum,
  • regulating the pressure of the injected fluid so as to maintain a pressure level in order to keep the inflatable structure in the final position,
  • constantly brake the axis of the drum so that it is the forces due to the pressurization of the structure that allow the deployment
  for the winding step of the inflatable structure,
  • starting the drum in the winding direction, exerting forces greater than at least the tension present in the inflatable structure so that said structure is wound continuously creating an overpressure in the upper part of the column,
  • evacuate the fluid through the upper part of the structure by means of a pressure relief valve.

For example, air, water or a gas is used as the fluid.
The deployment of the structure takes place substantially vertically.

• La figure 1, une structure de mât gonflable vu de profil,
• La figure 2, un détail de la partie inférieure du mât gonflable venant se fixer sur le touret motorisé,
• La figure 3, un détail de la partie supérieure du mât gonflable sur laquelle peut être fixée une charge,
• La figure 4 un schéma permettant de pré-dimensionner la structure, et
• La figure 5 une représentation de l'étape de montée ou de déroulement de la colonne.

Other features and advantages of the device according to the invention will appear better on reading the description which follows of an example of embodiment given by way of illustration and in no way limiting attached to the figures which represent:

• The figure 1 , an inflatable mast structure seen in profile,
• The figure 2 , a detail of the lower part of the inflatable mast being fixed on the motorized drum,
• The figure 3 , a detail of the upper part of the inflatable mast on which can be fixed a load,
• The figure 4 a diagram for pre-dimensioning the structure, and
• The figure 5 a representation of the step of raising or unwinding the column.

The figure 1 schematizes a profile view of an inflatable mast or inflatable column system. The system comprises, for example, a box 1 in which is disposed a drum 9, comprising an axis 9A and a mandrel 9M. The drum 9 is motorized, it is in connection with a motor 14 and a braking system 13. The braking system is, for example, a pneumatic system, a hydraulic system, or mechanical. The braking system can be mounted on the drum shaft. The braking system has the particular function of braking the axis of the reel, the braking force being less than the value of the torque exerted by the efforts of the inflatable structure on the axis of the reel. This value is detailed below. The inflatable structure or inflatable column 3 is wound on the drum 9. During the deployment of the inflatable column, the drum 3 is braked: the injection of a fluid under pressure from above and the tensile / tension forces in the material or fabric constituting the column causes it to rise at a constant or substantially constant speed. The deployment of the column is only by pressurizing the inflatable structure that constitutes it and by passive braking of the drum, in normal operation the system does not require the help of the engine. Braking of the drum is automatically generated on the axis 9A of the drum during the deployment phase. When folding, the motor of the drum is actuated forcing the evacuation of the fluid by a pressure relief valve. This inflatable column 3 is guided by a guiding device 4 when it leaves box 1. This guiding means 4 makes it possible to guide the outlet of the section of the column being inflated, for example a deviation from the planned elevation path for the column. This trajectory is initially defined. A pressure regulation system consisting of a compressor 5 or any other external source for injecting a fluid (exhaust pipe, bottle of compressed fluid, etc.) and a pressure regulator 5 (represented by the same reference in the figure, the block 5 comprising the compressor and the pressure regulator) is connected to an inflation tube 6 which is connected to the upper end 3s of the inflation column 3 via a (or several) inflation valve (s) 5v. Equipment 8 or load to be raised is for example positioned at the head of the inflation column by means such as pins 10i shown in FIG. figure 3 . The lower end 3i of the inflatable column is fixed for example by means of eyelets 11 i, figure 2 , on the drum. The equipment 8 constitutes a load for the inflatable column which must be taken into account for its dimensioning and also for the conditions for pressurizing the injected fluid.
In order to control the winding and the continuous unwinding of the drum, the system is for example equipped with a control and control panel 15. This device may also comprise means not shown in the figure, making it possible to determine at any time the value of the pressure of the injected fluid, to compare this value with a set value which can be stored in a database. This reference value can be deduced from external conditions to which the column to be inflated is subjected, for example, as a function of the wind speed. A remote remote control can also be used to remotely control the handling of the mast.

The figure 4 illustrates a diagram used for a predimensioning study of a cylindrical inflatable column. This comprises a first calculation of the type of material resistance adapted to the case of structures consisting of pressurized membranes determining the torque "inflation pressure-diameter of the mast".

In this example, the holding of the mast was verified taking into account a side wind of 100km / hour; the distributed load is denoted t and the force F, a slope or slope corresponding to the angle α is taken equal to 10 ° and a head load of 60 kg has a height h.
In the example given by way of illustration and by no means as a limitation, the characteristics of the coated fabric used for the finite element mechanical calculations (performed as a result of the material resistance type calculation) are listed in the following table. The web module represents the product of the Young's modulus by the thickness of the fabric. Similarly, the shear modulus of the web represents the product of the shear modulus by the thickness of the fabric. The tablecloth module concerning coated fabrics is used because, on the one hand, it has discontinuities, and the terminology used in Continuous Mechanics is to be used with caution, and on the other hand it is very difficult to define the thickness of a fabric, even coated, because of its sinusoids. Mechanical properties Module of tablecloth 460000 Pa.m Watershed shear modulus 165000 Pa.m Pam = Pascal unit x meter

• Le poids de l'antenne, P,
• Les forces de frottement de diverses natures, regroupant les forces de frottement entre le mât et le guide d'encastrement, le frottement dû au plissage de la membrane pressurisée. L'ensemble de ces frottements est représenté par une force Q,
• Le couple s'exerçant sur l'axe du touret noté r par les efforts exercés sur la membrane ou structure gonflable,
• La pression de gonflage, notée p ;

Ne sont pas prises en compte :

• Les forces dues au vent supposées horizontales et ne s'opposent donc pas au mouvement du mât car elles lui sont perpendiculaires,
• Les forces internes (contraintes) qui ne travaillent pas car le niveau de déformation de la membrane est supposé stationnaire du fait que la pression de gonflage reste constante.
• Les forces d'inertie supposées faibles car l'évolution du mât est supposée quasi-statique.

On note les grandeurs suivantes :

• P : poids de l'antenne au dessus du mât
• Q : force de frottement
• ┌ : le couple
• p : pression de gonflage du mât
• h: la hauteur du mât
• R : le rayon du mât
• r : le rayon du tambour

Pour formuler l'équilibre des forces mises en jeu, nous avons besoin d'évaluer le travail de ces forces entre deux positions voisines du mât. Entre ces deux positions, le mât s'est déplacé dans sa hauteur d'une quantité Δh et le touret a tourné d'un angle Δθ. Le volume se trouve ainsi réduit d'une quantité ΔV. Ces trois quantités cinématiques sont bien évidemment liées avec les relations suivantes : $$\mathrm{\Delta }\theta =\frac{\mathrm{\Delta }h}{r}\Delta V=S\mathrm{.}\mathrm{\Delta }h$$

The implementation of the system and method according to the invention is carried out for example by performing the steps described below, for an inflatable column, consisting, for example, of a membrane or material having the above characteristics.
The materials used are technical fabrics, also called flexible composites, made of textile fibers and a coating. Primarily, in inflatable structures, polyester fibers account for 90% of uses. The coating is made for example from elastomers (PVC, PTFE). The mechanical properties are given by the woven fibers while the coating protects the fibers and makes the seal.
The method is based on unwinding and winding an inflatable column around a drum. The system is packaged in the box 1 thus conferring a small footprint.
The control system, stored in the chamber 1, allows the injection of pressurized fluid at the upper part 3s of the inflatable column 3 via the inflation valve 5v. The vertical deployment kinematics results from the injection of the fluid under pressure from above, associated with a controlled unwinding by braking of the drum. The rise is regulated by the tensile forces in the fabric that must overcome the resistant torque of the drum. For this, the deployment of the inflatable column 3 is regulated by the brake system of the axis of the drum, the regulation system 5 and the pressure relief valve 7. The fact of injecting the pressure in the upper part of the column inflatable 3, allows to reveal (that is to say at the guiding means) only the section of the inflatable column which is at the equilibrium pressure, thus ensuring a mechanical stability. The tension exerted by the diaphragm under pressure at the equilibrium pressure is slightly greater than the braking forces which allows the vertical unwinding of the column. The value of the tension in the membrane is determined from the diameter, the pressure and the material used for the realization of the column. The braking force is dimensioned with respect to this voltage value and must be constant throughout the deployment phase. This principle allows the column to erect vertically and prohibited to pressurized fluid to get into the part still wound on the drum. The calculation below shows the calculation of the torque induced at the level of the reel axis by the tension forces in the membrane. This evaluation, however, requires some assumptions. Among the efforts involved, the method takes into account:

• The weight of the antenna, P,
• The friction forces of various kinds, combining the friction forces between the mast and the embedding guide, the friction due to the pleating of the pressurized membrane. All of these friction is represented by a force Q,
• The torque exerted on the axis of the drum noted r by the forces exerted on the membrane or inflatable structure,
• The inflation pressure, denoted p;

Not taken into account:

• The forces due to the wind supposed horizontal and do not therefore oppose the movement of the mast because they are perpendicular to it,
• Internal forces (stresses) that do not work because the level of deformation of the membrane is assumed to be stationary because the inflation pressure remains constant.
• The forces of inertia supposed weak because the evolution of the mast is supposed quasi-static.

We note the following sizes:

• P: weight of the antenna above the mast
• Q: friction force
• ┌: the couple
• p: mast inflation pressure
• h: the height of the mast
• R: the mast radius
• r: the radius of the drum

To formulate the balance of the forces involved, we need to evaluate the work of these forces between two positions close to the mast. Between these two positions, the mast has moved in its height by a quantity Δh and the drum has turned by an angle Δθ. The volume is thus reduced by a quantity ΔV. These three cinematic quantities are obviously linked with the following relations: $$\mathrm{\Delta }\theta =\frac{\mathrm{\Delta }h}{r}\Delta V=S\mathrm{.}\mathrm{\Delta }h$$

Les forces de frottement sont en général mal connues. Il conviendrait de les réduire au maximum lors de la réalisation du mât afin de ne pas pénaliser le dimensionnement du système de freinage et du moteur.
Donc, lors du déploiement du mât, les efforts de freinage devront être légèrement inférieurs à la valeur du couple r et lors du reploiement le couple moteur devra être supérieur à la valeur r.The balance of the mast and reel set is established using the virtual work principle which states that, in this case, the work of the external forces is equal to the work of the internal forces. We deduce the couple: $$\mathrm{\Gamma }=r\left(p\mathrm{.}\pi \mathrm{.}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="imgf0001.png"\; state="\{\{state\}\}">R</figure-callout>}}^2+Q-P\right)$$

Frictional forces are generally poorly known. They should be reduced as much as possible when the mast is being built so as not to penalize the sizing of the braking system and the engine.
Therefore, during the deployment of the mast, the braking forces will be slightly lower than the value of the torque r and when folding the engine torque must be greater than the value r.

The role of the pressure control system is in particular to maintain the equilibrium pressure level in the deployed portion of the inflatable column. The role of the pressure relief valve, placed at the top of the mast, is to secure the system. The pressure relief valve is dimensioned with respect to the internal pressure of the column. When the internal pressure exceeds the sizing value of the pressure relief valve, the fluid escapes automatically in order to keep the internal pressure constant at the desired value.
The internal pressure makes it possible to tension the membrane, to lift the load and to obtain the rigidity of the structure giving it its optimum mechanical resistance characteristics. By way of non-limiting example, a vehicle of more than one ton carries 4 tires inflated to about 2 bars, ie a surface of 0.8 m ² . The principle of the inflatable column is to raise a load of 60 kg using a surface of 0.2m ² , approximate section of the column with a pressure less than 2 bar.
The rigidity of the deployed structure is obtained by the coupling of the internal pressure and the reinforcement of the technical fabric used. Slings can also be used to stabilize the structure and to minimize movements of equipment stowed at the masthead +/- 20 cm around the equilibrium position, under extreme conditions of 10 ° and wind 100 km.h ^-1 . This makes it possible to guarantee an acceptable level of performance for various applications, measurements, camera. The structure is thus stabilized at a position and a pressure of equilibrium.
To fold the structure, an example of steps implemented by the method is described below. The forces exerted by the motorization of the drum must be greater than the tension in the inflatable column. This phenomenon will induce an overpressure in the upper part of the evacuated column by means of the pressure relief valve (s) 7 equipping the upper part of the inflatable column and the pressure regulating system. The mast or column 3 then wraps around the drum 9. The descent of the inflated column is performed using the motorization of the drum, it continuously winds the initially inflated column, creating an overpressure in the part top of the column, because it is the lower part of the inflated column which is wound first. This excess pressure is evacuated automatically by means of (s) valve (s) of pressure. This method makes it possible to maintain the upper part of the column at its equilibrium pressure, the latter being dimensioned to withstand the external loadings mentioned above. The column thus remains vertical during its folding. The deployment and folding operations also use the following geometrical feature: the median axis 3A of the column is tangent to the outer generator of the drum. Axis 3A is represented on the figure 1 . Everything is done naturally using the tensile forces of the membrane constituting the column. The reliability of the system is greatly improved.

The fluid used may be air or any other gas. In some cases of use, in case there is no source of gas, it would be possible to inject a liquid playing the same role and provide a liquid evacuation system.
The inflatable column is, for example, equipped with means 12 ( figure 1 ) allowing the attachment of anchoring means to stabilize, the attachment means not being shown for reasons of simplification.

The manner of operating described above has the following advantages in particular. The non-folding, involving if necessary the ruin of the structure under the combined external forces, is checked. The resistance of the technical fabric coated to the forces generated by the inflation pressure is verified. The reduced storage volume, of the order of a quarter of the volume required for an equivalent mechanical structure.

Claims (9)

System for moving an object initially arranged in a first position to a second position characterized in that it comprises in combination at least the following elements: ○ a drum (9) controlled in movement, said drum receiving an inflatable structure (3), the drum being in connection with a braking system (13), ○ said inflatable structure (3) being provided in its lower part (3i) with fixing means (11 i) on said drum (9) and in its upper part (3s) of fastening means (10i) of the object to move (8), ○ a fluid injection device (6) and a pressure relief valve (7) at the upper part (3s) in said inflatable structure, via a pipe (6) and a means of pressure regulation (5), ○ a guide means (4) of said inflatable structure. System according to Claim 1, characterized in that the inflatable structure (3) is an inflatable column and the displacement is a displacement in elevation. System according to one of claims 1 or 2 characterized in that the fluid is selected from one of the following elements: air, water, a gas. System according to claim 1 characterized in that the drive means (2) is a motor for continuous movement of the drum. System according to claim 1 characterized in that said inflatable structure is manufactured in one of the following materials: coated polyester fibers, the coating being made from elastomers. System according to one of claims 1 to 4 characterized in that said inflatable structure is provided with means (12) for attaching anchoring means to stabilize it. Method for moving an object initially arranged in a first position in a second position by means of an inflatable structure (3) which can be wound on a motorized reel (9) having an axis (9A) and controlled in motion, characterized in that has at least the following steps: the structure (3) being in position wound around the drum (9), for the unwinding step of said structure (3): Injecting a fluid into the upper part (3s) of said inflatable structure at a pressure value chosen according to the conditions external to the structure and the characteristics of the object to be moved by guiding said column at the outlet of the drum (9), between the drum (9) and the casing (1) in which the inflatable structure (3) and the drum (9) are arranged, Regulate the pressure of the injected fluid so as to maintain a pressure level in order to keep the inflatable structure in the final position, • steadily brake the axis of the reel so that it is the forces due to the pressurization of the structure that allow the deployment for the step of winding the inflatable structure (3), • start the drum (9) in the winding direction, exerting forces greater than at least the tension present in the inflatable structure so that said structure is wound continuously creating an overpressure in the upper part of the column, • evacuate the fluid through the upper part of the structure by means of a pressure relief valve (7), Process according to Claim 7, characterized in that air, water or a gas is used as the fluid. Process according to Claim 7, characterized in that the deployment of the structure is substantially vertical.

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