WO2002099172A1

WO2002099172A1 - Variable structure fabric and the uses for it

Info

Publication number: WO2002099172A1
Application number: PCT/IB2002/002006
Authority: WO
Inventors: Cristian Lira
Original assignee: Angrilli, Francesco; Debei, Stefano
Priority date: 2001-06-05
Filing date: 2002-06-05
Publication date: 2002-12-12
Also published as: ITBO20010359A1; ITBO20010359A0

Abstract

The invention relates to a variable structure fabric and the uses for it, in particular for upholstery, technical clothing, underwear, vehicle interior linings and deployable structures. The fabric (1) comprises a pattern (3) with a plurality of deformable element (14), a control module (2) connected to the pattern (3) through a plurality of connecting tubes (4). The module (2) comprises a processing unit (70), a first user interface (8, 26) connected to the processing unit (70) to allow the user to control the processing unit (70) , an accumulator (9) of fluid under pressure, a distributor (13) controlled by the processing unit (70) and connected to the accumulator (9) and to the tubes (4) to regulate and distribute the fluid under pressure to the pattern (3). Alternatively, the deformable elements (14) may be made of a shape memory alloy (SMA).

Description

Variable structure fabric and the uses for it

Technical field

The present invention relates to a variable structure fabric and the uses for it. In particular, the fabric disclosed by the present invention can be used to substitute materials that come into contact with the user's body. For example: the fabric may be used for shoe inserts, upholstery, underwear and parts of the interior of a vehicle, such as dashboard, seats, side panels and roof liner.

Another use for the invention is in structures known to experts in the trade as deployable structures.

Background Art

United States patent US-5,589,245 discloses a textile spacer material consisting of two outer covering layers with a padded part between them. The fabric structure can have several different configurations. Once the structure has been defined, however, it cannot be modified or adapted to different requirements. For example, in the case of a seat for a vehicle, the shape and thickness of the padding cannot be adapted to the user's body. United States patent US-6,101,630 discloses a brassiere having cups with fluid-filled bags designed to improve the appearance of the wearer. Although the volume of the bags can be touched up to a small extent, it cannot, once defined, be varied according to the outer garment being worn. Flexible actuators are known from Italian patents IT-

1.292.355 and IT-1.293.899 which disclose, respectively: a muscle actuator and an elephant's trunk actuator for biomedical applications and for handling objects using robots or manipulators, for example. Again, the structures of these actuators are such that they cannot be used to vary the structure of the fabrics. Disclosure of the invention

In the variable structure fabric according to the present invention, the mechanical and control principles of flexible actuators as currently applied to industrial robots are used to integrate actuators into the fabric structure in order to be able to vary the structure so that it will dynamically conform to the body that is wrapped in and/or supported by the fabric or to vary the shape of the structure to which it is applied, as when it is used to actuate deployable structures . In another embodiment, the variable structure fabric according to the present invention uses miniaturised actuators based on electromechanically active material, also known as SMA actuators, that is, actuators with elements made of shape memory alloy. This type of material is based on the change of shape caused by the transformation of an austenitic crystal lattice into a martensitic crystal lattice.

The above mentioned technical needs and aims are substantially fulfilled by a variable structure fabric as described in the accompanying claims.

Other technical characteristics of the invention and its advantages will become more apparent from the detailed description which follows .

Description of the drawings

Below is a description of preferred, non-limiting embodiments of a variable structure fabric illustrated in the accompanying drawings, in which:

Figure 1 is a schematic ^• front view of the variable structure fabric according to the present invention;

Figure 2 is a schematic front view of the control module of the variable structure fabric of Figure 1;

Figure 3 is a front view of a part of the present invention; - Figure 4 is a front view of another part of the present invention; Figure 5 is an enlarged front view of the fabric according to the present invention;

Figure 6 is a front view of another embodiment of a detail of the fabric according to the present invention;

Figures 7, 8 and 9 are front views of different embodiments of details of the fabric according to the present invention;

Figures 10, 10a, 10b and 10c are sections of another embodiment of the fabric according to the present invention;

- Figure 11 is a front view of another embodiment of a detail of the fabric according to the present invention;

Figures 12 and 12a show another embodiment of a detail of the fabric of Figure 11 in a front view and an enlarged view;

Figure 13 is a side view of another detail of the present invention; and

Figure 14 shows yet another embodiment of the fabric according to the present invention based on SMA actuators.

Description of the preferred embodiments of the invention The present specification expressly refers to flexible actuators driven by a fluid under pressure. However, it is also possible to use minitiarised actuators based on electromechanically active material, also known as SMA actuators, that is, actuators with elements made of shape memory alloy. There is a substantial analogy between the two types of actuators, as shown in the table below:

With reference to the drawings listed above, the variable structure fabric according to the invention is denoted in its entirety by the numeral 1.

It essentially comprises a pattern 3, a control module 2 connected to the pattern 3 through a plurality of tubes 4, a pressure/force sensor 5, and a position sensor on the surface electrically connected to the module 2 through a plurality of electric wires 6.

As shown in more detail in Figure 2, the control module 2 comprises a processing unit 70, for example a microprocessor 7, a first user interface, for example a selector 8, an accumulator 9 of fluid under pressure, a second interface 10 between the microprocessor 7 and the accumulator 9 of fluid under pressure, a safety device 11 used to discharge fluid pressure into an appropriate tank in the event of excessive movement and/or pressure in the pattern 3; an internal pressure sensor 12 that detects the pressure of the fluid in the pattern 3 and sends a signal to the microprocessor 7, and flow rate/pressure distributor 13 controlled by the microprocessor 7.

As shown in more detail in Figure 3, the pattern 3 consists of deformable elements 14 having a suitable shape and made of a suitable material. The materials used are preferably neoprene™ or other materials having similar properties .

In the embodiment illustrated in Figure 3, the pattern 3 consists of a set of tubular elements 15 arranged like the fibres of a commercial fabric. The tubular elements 15 can be made in different sizes.

For example, the tubular elements 15 can be made in relatively large sizes to be used in structures that stretch and take shape, known to experts in the trade as deployable structures, and in smaller sizes comparable to those of a commercial fabric.

The fluid flowing in or out causes a change in the pressure inside the tubular elements, deforming the pattern 3 and thereby creating a new configuration of the mesh or, more generally, of the tubular elements 15.

In the case of the SMA actuators illustrated in Figure 14, the actuators comprise elements 29 which, following application of electric current I to portions of the circuit (and at the same time, if necessary, varying the voltage V across defined points in the circuit) change their shape and give the pattern 3 a new configuration . Figures 7, 8 and 9 illustrate different embodiments of the tubular elements 15. In Figure 7, the tubular element 15 is divided lengthways and comprises two parts of different rigidity: the front part 16 being more rigid and the back part 17 more flexible. As internal pressure increases, the tubular element bends and is deformed as shown by the dashed line in Figure 7.

Figure 8 illustrates another embodiment of the tubular element 15 made of a single flexible material and comprising a thread 18 made from an inextensible material. The deformation resulting from the increase in internal pressure is indicated by the dashed line and is similar to that illustrated in Figure 7.

Figure 9 illustrates yet another embodiment of the tubular element 15 consisting, in this case, of a flexible curved part 19 that joins two more rigid parts 20 and 21. Again, the pressure increase varies the configuration of the tubular element 15 as shown by the dashed line.

Figure 6 shows another embodiment of the pattern 3. In this embodiment, the structure of the pattern 3 does not consist of woven fibres as in commercial fabrics, but comprises a series of chambers 22 ranging in size from 0.1 to 5 mm.

In the case of application to deployable structures, their sizes may be much larger, of the order of 20-30 mm.

The chambers 22 are made in such a way as to be arranged in a predetermined fashion when the fluid inside is under a predetermined pressure, and to change their shape, that is to say their relative arrangement, and hence the shape of the pattern 3, when the fluid pressure increases.

Similarly, the change in the shape of the chambers 22 can also be achieved using appropriately arranged SMA actuators. Figures 10 10a, 10b, and 10c illustrate another embodiment of the present invention applied to a brassiere cup. In this case, the pattern 3 has a simplified structure and comprises one chamber 22a or two chambers 23, 24 containing the fluid under pressure. By a suitable alternation of flexible and less flexible material on the sides and extensions of the walls of the chamber 22a or of the chambers 23, 24, it is possible to change the shape of the containing portion of the brassiere cup in a desired fashion. By acting only on the shape of the chambers 22a, 23 and 24, the shape of the entire cup can be changed.

Figures 10 and 10a illustrate an embodiment having a single chamber 22a. By varying the pressure in the chamber 22a, or modifying its shape through the SMA actuators, the chamber 22a produces a rotation and/or a variation of the containing walls of the brassiere cup.

Figures 10b and 10c illustrate another embodiment having two chambers 23 and 24.

In this case too, by varying the pressure in the chambers 23, 24 or modifying their shape through the SMA actuators, the chamber 23, 24 produce rotations and/or variations of the containing walls of the brassiere cup. The variations in the chambers 23, 24 may also be combined in different ways: both chambers 23, 24 under pressure, or one chamber only - chamber 23 or chamber 24 alternately - or neither of the two chambers 23, 24.

These rotations and/or variations of the walls may be modulated and graduated: for example, Figure 10c shows some possible variations of the containing walls following progressive variations of the pressure in the chambers 23, 24.

With other types of clothing, the variable structure fabric according to the invention may even be used to vary only the contact pressure with the part wrapped in or supported by the fabric.

For example, the variable structure fabric according to the invention may be used in shoes capable of simulating the force of gravity on the foot or it may be used to move parts of the body during passive exercises or to help the wearer perform a desired movement.

Figure 11 shows a specific embodiment of the structure illustrated in Figure 3. In this embodiment, the fabric consists basically of elements 15 of the type illustrated in Figure 12, which are tubular in shape and around which an inextensible thread 18 is wound to form loops 18a at defined intervals.

The end result is in any case a change in the geometry and shape of the pattern 3. Starting from a rest condition in which the pattern 3 has a predetermined shape, the pressure of the fluid inside the deformable elements 14 can be increased in such a way as to alter the shape of the pattern 3.

As described above and for some applications, instead of the actuators shown in Figures 6, 7, 8, 9, 10, 12, the pattern 3 may be combined with a pattern portion formed from deformable elements

14 having similar functional elements 29 made with the SMA { shape memory alloy) actuators.

SMA actuators consist of elements 29 made of special alloys. By appropriately heating these elements in certain predetermined positions, it is possible to obtain a desired change in their configuration .

Heating may occur directly inside the element through the Joule effect created by passing a current through the element. For this reason, the actuator with SMA elements 29 has zones

29a with a narrower section (Figure 14) . This increases electrical resistance and hence heats the elements at these zones in such a way as to change the shape of, and thus move, the actuator.

In .another embodiment (not illustrated) the actuator with SMA elements has a continuous structure and the Joule effect is distributed uniformly along the entire element so that the movement of the actuator is also distributed uniformly along the length of the element.

In yet another embodiment (not illustrated) the actuator with SMA elements is heated by external heaters (electrical by Joule effect, or other types of heaters) that are in direct contact with the element to be heated.

In all cases, the actuators with SMA elements are functionally equivalent to the actuators shown in Figures 6, 7, 8, 9, 10, 12, which work by transferring volumes of fluid or by varying the pressure of the fluid.

The result is that the pattern 3 wraps, supports and gives shape and movement to the body, or the pattern 3, by changing its geometry and shape, makes it possible to move the deployable structure. A useful feature of the present invention is the presence, on the surface of the pattern 3, of the pressure/force sensor 5, and of a position/relative motion sensor, which operate by area.

However, in a simplified embodiment, the sensor 5 may be omitted.

The sensor 5 that detects pressure (and hence force) and relative motion on the surface may be of the capacitive, inductive, piezoelectric or any other suitable type.

As regards position and relative motion, the sensor may also be of the optical, electro-optical, inductance variation or similar type.

In the case of application to an item of upholstery or clothing in direct contact with the skin, the sensor 5 may be of the capacitive type and consists of two armatures (not illustrated) of which one may even be the user's body.

The position sensor may also be an external sensor 27. For example, as illustrated in Figure 13 applied to a deployable structure, the sensor 27 is a contactless measuring element, for example an external camera, or a sensor that detects infra-red or other rays in the invisible frequency range, or an ultrasonic sensor.

Thanks to the sensor 5, the variable structure fabric 1 according to the present invention is elastic, pliable and capable of detecting the pressure exerted by the body against different points of the pattern, thus enhancing the comfort of the person wearing the item of clothing or resting his or her weight on the fabric 1.

In ^' the case of the sensor 27, the sensor signal is sent through transmission means 28 to the electrical wires 6 of the module 2 to indicate that the movement of the structure to which it is applied has been completed, and creating a feedback loop that enables self-adjustment.

In the case of deployable structures, the sensor 27, which may be a camera or one of the other types of sensor, supervises the action of the deployable structure. The sensor 5 is normally fitted between the body of the person wearing the item of clothing) or resting on the fabric 1) and the pattern 3, which is the moulding part.

Similarly, in the case of deployable structures, the sensor 5 adheres to the structure, while, as mentioned above, the sensor 27 is located outside.

Depending on where the pattern 3 is used, however, a sensing system may also be applied to the surface of the pattern 3 that is not in direct contact with the part of the user's body supported or moulded, this arrangement also being possible for deployable structures .

It should be noted that the sensor 5 is divided into a plurality of sensing elements 5a, pressure and force sensors, each of which detects the pressure/force in a particular part of the fabric and generates a corresponding pressure/force signal.

In addition, the sensor 5 may be combined with a position sensor or a relative motion sensor, also consisting of a plurality of sensor elements, each of which detects the displacement/position in a particular part of the fabric and generates a corresponding signal.

The sensor signals are then processed by the microprocessor 7 and are used to drive the distributor 13.

The distributor 13 also controls the shape of the pattern 3 by area, that is to say, it is equipped with a plurality of adjustment units (not illustrated) , each of which selectively varies a different area of the pattern 3 corresponding to a cell under pressure.

The module 2 accordingly controls the fluid flowing into or out of the pattern 3 under pressure. For the embodiment based on actuators with SMA elements, the signals processed by the microprocessor 7 are used to drive the actuator in terms of electric voltage V and electric current I, through a corresponding circuit which is also divided into a plurality of adjustment areas. At the same time, the pressure sensor 5 located on the surface of the pattern 3 detects the interaction between the body wrapped in or supported by the fabric and generates a corresponding signal. The control module 2 accordingly operates on the distributor 13 to cause fluid to flow between the different cells under pressure within the pattern 3.

In the case of the actuators with SMA elements 29, the action of the control module 2 causes the necessary variations of current in the heating circuits or in the elements 29 of the actuator itself.

The shape of the pattern 3 is thus controlled by the feedback signal generated by the sensor in response to the pressure and/or force and/or displacement, or, more generally, the relative motion, of the body of the person using the fabric 1.

The pattern 3, therefore, makes it possible, even dynamically, to mould the body wrapped in or supported by the pattern 3 itself or to actuate the deployable structure. If the sensor 5 is not fitted, the module 2 confers on the pattern 3 a set of predetermined shape configurations without the dynamic control in response to feedback from body movements.

The distributor 13 distributes/regulates the fluid flowing into/out of the chambers inside the elements 14 forming the pattern 3 and may consist of a plurality of servovalves driven electrically, hydraulically or pneumatically depending on the application.

In the case of the actuators with SMA elements, the adjustment is carried out by varying the current I and/or the voltage V.

The above mentioned distributing/regulating valves are of the type currently used in handling systems such as industrial robots. For the fabric according to this invention, the servovalves are greatly reduced in size. An example of these servovalves, also known to experts in the trade as MEM's (Micro Electro Mechanical structure), can be found in patent publication US-6 055 899, the disclosure of which is incorporated herein by reference.

The accumulator 9 of fluid under pressure is also particularly compact so as to reduce the overall dimensions of the actuating system that supports and moulds the shape of the body by adjusting the shape of the pattern 3. In applications where pressure is not generated otherwise, a small volumetric pump 9a is fitted to keep the pressure in the accumulator 9 at a constant level . The pump 9a can be detached from the accumulator 9 in order to keep overall dimensions down to a minimum. In the case of the actuators with SMA elements, the pump 9a is substituted by a generator of electric potential different Δv and the accumulator is substituted by a rechargeable (electric) battery. To reduce power consumption, the areas or portions to be heated by the Joule effect are limited as much as possible. In the case of the fluid actuators, it should be emphasised that the dissipation of system energy is minimal because the variations in the shape of the pattern 3 are accomplished mainly by varying the pressure within the deformable elements 14 and not by displacing volumes of fluid, thus minimising load losses. Consequently, the accumulator 9 need only be recharged occasionally to restore pressure.

For this reason, the fluid preferably used is incompressible, for example, water or a mixture of water and additives to reduce evaporation. However, for some applications such as in vehicles, for example, the use of a gas is to be preferred. For example, the fluid used is air or an inert gas such as nitrogen.

The use of a microprocessor, which has the advantage of being very compact, does not exclude the use of other systems which might equally effectively control the shape of the pattern 3.

For example, the processing unit 70 might consist of functional devices capable of substituting or enhancing the controlling action of the microprocessor 7, such as, for example, dedicated wired systems or the like, which may be added to or may interact with the pattern 3.

The control module 2 includes an interface for the processing unit 70, which may consist of a selector 8, enabling the user to interact with the fabric system in order to achieve desired support or movement (in the case of deployable structures) or similar conditions. The microprocessor 7, whether programmable or not, contains programs or links between the commands sent and the action of the pattern 3 on the body of the person - or on the deployable structure - using the variable structure fabric 1. The interface between the user and the processing unit 70 may be an element that is separate from the module 2. In this case, too, the interface must be able to communicate with the module 2 to allow the user to interact with the variable structure fabric 1. In this case, as illustrated in Figure 2, the interface may be a remote control 26 that can be connected to the module 2 only when necessary. Communication between the remote control 26 may be achieved through an electrical or inductive connection or through radio or infrared signals. Some of the functions, such as the safety devices, which are an integral part of the system, do not require the user interface since they are performed automatically.

The safety device 11 constantly checks the fluid pressure and reduces it when it exceeds a defined level considered dangerous or unsuitable. The actuators with SMA elements 29 are equipped with a safety device which checks dangerous or unsuitable values of voltage V and current I .

This safety system, by monitoring fluid pressure, makes it possible to control the effects of the dilation of the fluid due to variations in temperature or other causes, also preventing all excessive movements of the parts of the fabric where the pressure is above a defined value.

Another embodiment of the fabric according to the present invention, made from elements 15 of the type illustrated in Figures 7, 8 and 9 is used in deployable structures. Certain points of the pattern 3 are connected to the deployable structure and, as they move, cause a variation in the pressure in the elements 15, allowing the structure to be opened or closed.

The behaviour of the pattern 3 made from SMA elements 29, is similar.

In the case of applications to clothing, the control module 2 can be separated from the pattern 3 to allow washing of the item of clothing or maintenance and/or substitution of the module 2 itself. For this purpose, the module 2 has a connector 25 equipped with suitable means for retaining the fluid.

In the case of applications to clothing with actuators made from SMA elements 29, the control module 2, with the rechargeable battery, and the generator of potential difference ΔV can be separated from the item of clothing.

The invention achieves important advantages.

The use of deformable actuators which are interwoven or otherwise interconnected, or which are applied separately in particular positions within the fabric creates a system capable of: conforming to the body (while supporting and giving shape to it) and, if necessary, moving the body or the part of it that is wrapped in or supported by the fabric. In the version with pressure (force) sensor and with position (and/or relative motion sensor) , the use of a microprocessor, enables feedback control using the signals (pressure, force, displacement) from the pressure/force sensor 5 and from the relative motion sensor, which are fitted in such as to provide significant signals as to how the body and the fabric are interacting.

The invention as described above may be modified and adapted in several ways without thereby departing from the scope of the inventive concept as defined in the claims.

Moreover, all the details of the invention may be substituted by technically equivalent elements

Claims

1. A variable structure fabric (1) and the uses for it, in particular for upholstery, technical clothing, underwear, vehicle interior linings and deployable structures, the fabric (1) comprising a pattern (3) having a plurality of deformable elements (14) and being characterised in that it comprises a control module (2) connected to the pattern (3) through connecting means (4).

2. The variable structure fabric (1) according to claim 1, characterised in that the module (2) comprises a processing unit (70) , a first user interface (8, 26) connected to the processing unit (70) to allow the user to control the processing unit (70), an accumulator (9) of fluid under pressure, a distributor (13) controlled by the processing unit (70) and connected to the accumulator (9) and to the means (4) to regulate and distribute the fluid under pressure to the pattern (3) .

3. The variable structure fabric (1) according to claim 1, characterised in that the plurality of deformable elements (14) comprises elements (29) made of a shape memory alloy.

4. The fabric (1) according to claim 1 or 2, characterised in that the deformable elements (14) comprise tubular elements (15) consisting of two parts (16, 17; 18; 19, 20, 21) of different rigidity.

5. The fabric (1) according to claim 4, characterised in that the deformable elements (14) comprise a thread (18) made from an inextensible material.

6. The fabric (1) according to claim 1 or 2, characterised in that the deformable elements (14) comprise a series of chambers (22) made in such a way as to be arranged in a predetermined fashion when the fluid inside is under a predetermined pressure and to change their arrangement, and hence the shape of the pattern (3), when the fluid pressure increases.

7. The fabric (1) according to claim 1 or 2, characterised in that the deformable elements (14) consist of at least one chamber (22a; 23, 24) whose walls have parts made of a flexible material and other parts that are less flexible, so that the shape of the chamber (22a; 23, 24) can be changed.

8. The fabric (1) according to any of the foregoing claims, characterised in that it comprises a pressure sensor (5) mounted on its surface and electrically connected to the module (2) to detect the pressure between the pattern (3) and the user in contact with or close to the pattern (3) and to generate a corresponding pressure signal.

9. The fabric (1) according to any of the foregoing claims, characterised in that it comprises a displacement sensor (5) mounted on its surface and electrically connected to the module

(2) to detect the relative motion between the pattern (3) and the user, or in the deployable structure, in contact with or close to the pattern (3) and to generate a corresponding signal.

10. The fabric (1) according to any of the foregoing claims, characterised in that the processing unit (70) is a microprocessor (7) .

11. The fabric (1) according to any of the foregoing claims, characterised in that it comprises a safety device (11) used to relieve fluid pressure in the event of excessive movement and/or pressure in the pattern (3) .

12. The fabric (1) according to any of the foregoing claims from 3 to 11, characterised in that it comprises an internal pressure sensor (12) that detects the pressure of the fluid within the pattern (3) .

13. A deployable structure characterised in that it comprises a part made from the fabric (1) according to any of the foregoing claims to move the structure.

14. An item of clothing characterised in that it comprises at least one part made from the fabric (1) according to any of the foregoing claims from 1 to 12.