FR2652603A1 - DEVICE FOR THE TENSIONING OF A SUN PROTECTION FABRIC, ESPECIALLY FOR VERANDA OR PERGOLA. - Google Patents

Abstract

The device tensions a fabric (1) horizontally deployed above a structure such as a verandah or pergola (2), the fabric (1) having one end joined to a winding member (3) and its opposite end being joined to a movable load bar (5) whose translational movement (6, 7) is guided. Two spring-loaded extendable arms (8, 9) are each mounted, in an articulated manner, between a stationary point (13, 18) close to the winding member (3) and a movable point joined to the load bar (5). These arms (8, 9), urged by their springs in the direction of their extension, exert a thrust on the bar (5) tending to move it away from the winding member (3) and to tension the fabric (1).

Description

* 4 The present invention relates to a device for maintaining

  tension of a sun protection fabric, of the kind deployed horizontally or with a slight inclination above a structure such as veranda, pergola, greenhouse or other similar construction, having a framework on which can be mounted sun protection system. This invention applies, more particularly, to a sun protection fabric, one end of which is linked to a rotating winding member, preferably motorized, and the opposite end of which is linked to a movable load bar, comprising means in translational guidance. Such a sun protection system thus has at least one fabric that can be deployed or rolled up, the load bar moving away from the winding member as the canvas is deployed, the useful part of which extends between the winding member and this load bar. Because of their large size and their horizontal or slightly inclined position, such fabrics offer a significant wind resistance,

  and must therefore be tight.

  To obtain the tension of the fabric, tensioning devices are currently used, which are all of a fairly similar principle: the fabric is generally stretched by means of a tension or torsion spring, and sometimes by a geared motor, which exerts an action on the load bar. The force of the spring or of the gearmotor is transmitted to the load bar by means of at least one cable, a textile strap or even a metal strip, so as to pull the load bar,

  in the direction of its distance from the winding member.

  A particular known solution is represented by French patent N 85 0 # 059 / 2,578,901 filed March 12, 1985 in the name of ETABLISSEMENTS LAUZIER; this document describes a tensioning device, comprising at least one cable with one strand attached to the load bar of the fabric and with another strand linked to winding means, driven in synchronism with the winding means of the Web; the cable passes here on a deflection pulley which is stressed by means to

  spring in the direction of the tensioning of this cable, therefore of the fabric.

  Each cable is advantageously wound on a tapered drum, forming successive turns of variable diameter,

  allowing an exact compensation of the length of the fabric.

  Other existing embodiments also use winding means and deflection pulleys for cables, straps or strip, with various arrangements. The compensation of the differential elongations existing between the fabric on the one hand, and the cable, the strap or the strip on the other hand, is obtained according to the manufacturers either by a tension spring located inside the load bar, either by a spring of

  torsion housed inside the tubular fabric winding member.

  The current tensioning devices, mentioned above, have a certain number of drawbacks: 1. They impose the presence of an unsightly additional winding tube on the side opposite to the canvas winding tube, or else two lateral slides which serve both as guides for the ends of the load bar and as return means (with pulleys) for the system

  with cable, strap or strap.

  2. The slides and other guiding means such as rails, supporting or guiding the pulleys, must be perfectly

  parallel to each other and perpendicular to the winding tube (s).

  3. These geometrical constraints complicate the installation of the protective fabric and its tensioning device; the pose is therefore long

and delicate.

  4. Traction systems, such as cables, must have a predetermined length with accuracy to ensure the expected tensions

on the Web.

  5. These traction systems are subjected to high tensions, incompatible with the small diameter pulleys over which they must pass, as well as with their own dimensions, these systems being themselves of small section so as not to have too much bulk. important when rolled up; as a result, said systems deteriorate

  fairly quickly, and their operation is noisy.

  The present invention aims to avoid all these drawbacks, by providing a device for maintaining tension in a new and simple design, which entirely eliminates the traction systems such as cables or straps, therefore also the return pulleys and the guide means. necessities by these pulleys, hence a simplification of construction and installation, while ensuring reliable and suitable operation providing, in particular, a

  substantially constant tension force.

  To this end, the subject of the invention is a device for maintaining the tension of a sun protection fabric, in particular for a veranda or pergola, of the kind specified in the introduction, in which the tensioning means comprise at least two arms extensible with springs, each mounted in an articulated manner between a fixed point close to the fabric winding member and a mobile point linked to the load bar, so that these extensible arms, biased by their springs in the direction of their elongation, exert on the load bar a push tending to

  move it away from the canvas winding member.

  Thus, the invention proposes the replacement of current traction systems on the load bar by a pushing device, with extendable arms, bearing on fixed points which may be points on the chassis supporting the winding member of the canvas, these arms exercising

  their action directly on the load bar.

  In an advantageous embodiment of the invention, the tension-maintaining device comprises at least two extensible spring arms with an overall configuration in "X", the two arms crossing and being articulated with one another in their central parts , and each being articulated, at one end, at a fixed point close to the fabric winding member and, at the other end, at a mobile point linked to the load bar. Each extendable arm here preferably comprises a first telescopic tension element articulated at the fixed point and connected, by an intermediate element articulated on the corresponding element of the other extendable arm, to a second telescopic tension element, articulated at the point

mobile linked to the load bar.

  The configuration in "X" makes it possible to obtain a tension of the fabric which is substantially constant, for all the positions of the load bar corresponding to a fabric which is quite unrolled therefore requiring effective tension maintenance. This "X" configuration also has the advantage of being well suited to a canvas with a large range, even with a reduced width, the two arms being retracted and placed one parallel to the other when the canvas is fully rolled up. In addition, the assembly formed by the two "X" arms can be pre-assembled in the factory, then easily transported and installed. This set is compact and self-supporting, and does not require any special support or guide; it is simply mounted in an articulated manner, for example by means of ball joints, between a fixed chassis element on the one hand and the load bar on the other hand, and it remains entirely independent of the means for guiding the load bar and of the structure of the veranda, achievable for example according to the request of

  French patent N 89 01844 filed on February 13, 1989 in the name of S.A.

FRANCIAFLEX.

  According to another embodiment of the invention, the tension-maintaining device comprises at least two extensible spring arms with an overall "V" configuration, each of the two arms being articulated, at one end, at a point fixed near the fabric winding member and, at the other end, at a mobile point linked to the load bar. The two extendable arms, which can each comprise a single telescopic tension element here, are for example articulated at the

  same fixed point, and deviate from each other from this fixed point.

  Two or more pairs of "X" or "V" extendable arms

  can be combined, in the case of large width fabrics.

  According to another characteristic, the or each telescopic tensioning element of an extendable arm comprises a central rod linked to a first end-piece provided at one end of the element, a tube linked to a second end-piece located at the opposite end of the element, and a tubular cover surrounding the central rod, linked to the first end piece and sliding on the tube linked to the second end piece, a helical spring being mounted, with its ends pressed against the two end pieces, around the central rod and under the tube cited above. Preferably, the central metal rod is coated on the outside with a protective plastic sheath, while the tube, also metallic, has a protective internal coating in plastic; thus, the coils of the spring come into contact with plastic parts, which considerably reduce friction

and noises.

  In any case, the invention will be better understood using the

  description which follows, with reference to the accompanying schematic drawing

  representing, by way of nonlimiting examples, some embodiments of this device for maintaining tension in a sun protection fabric, in particular for veranda or pergola: Figure 1 is a general view, in perspective, of a sun protection fabric fitted with a tension maintenance device according to the invention; Figure 2 is a plan view from above of the fabric of Figure 1 and its tension maintenance device, in the folded position; Figures 3, 4 and 5 are plan views, very schematic, of variants of this tension maintenance device Figure 6 is a detail view, on an enlarged scale and in longitudinal section of a telescopic tension element of the device according to l 'invention. As shown in FIGS. 1 and 2, the tension maintenance device is applied to a sun protection fabric 1 deploying horizontally, or with a slight inclination either upwards or downwards, above a structure such as veranda, the framework of which is indicated in 2. The fabric 1 has a rear edge linked to a winding tube 3, mounted rotating around a horizontal axis 4 and coupled to an electric drive motor, not shown , which can be housed inside the tube 3. The front edge of the fabric 1 is moored to a movable load bar 5, which is guided by means of pads 6 along guide rails 7 fixed to the frame of the veranda 2, these rails being able to be elements such

  that rafters belonging to the frame itself.

  The fabric 1 tensioning device comprises, in the embodiment according to FIGS. 1 and 2, two extensible arms 8 and 9 with an overall configuration in "X", that is to say two arms crossing in their central parts, where they are articulated to each other along an axis 10. Each arm 8 or 9 is mounted between a fixed frame element 11, supporting the winding tube 3, and the bar load 5. More particularly: - the first arm 8 comprises a posterior telescopic tension element 12, articulated at 13 to the left part of the chassis element II and connected, by means of a central part 14, to a front telescopic tensioning element 15, articulated at 16 on the right part of the load bar 5; - The second arm 9 comprises a posterior telescopic tensioning element 17, articulated at 18 to the right part of the chassis element 11 and connected, by means of a central part 19, to an anterior telescopic tensioning element 20 , articulated at 21 on the left side of the bar

charge 5.

  The respective central parts 14 and 19 of the two extensible arms 8 and 9 are articulated to each other around the aforementioned axis 10. Each telescopic tension element 12,15,17,20 contains a spring which tends to elongate this element, therefore also to extend the corresponding extensible arm 8 or 9, the detailed configuration of the tension elements being described below. FIG. 3 shows a first variant of the tension maintenance device, with two extendable arms 22 and 23 having an overall configuration in "V", each arm 22 or 23 being able here to comprise a single telescopic tensioning element with spring. The posterior ends of the two arms 22 and 23 are linked by the same articulation 24 to the central part of the fixed frame element 11, and move away from one another starting from the articulation 24; the first arm 22 has its anterior end articulated at 25 to the left part of the load bar 5, while the second arm 23 has its anterior end articulated at 26 to the part

load bar 5.

  For a very wide fabric 1, as shown in FIG. 4, the tension-maintaining device may comprise four extendable arms, that is to say two pairs of arms in "V" shape with a first pair of arms 22, 23 as described below. above, and a second pair of arms 27, 28 identical to the previous one. In another variant, illustrated by FIG. 5, the two extensible arms 22 and 23 retain an overall configuration in "V", but they are articulated at two distinct points, respectively 29 and 30, on the

  central part of the fixed chassis element 1I.

  Figure 6 shows the detail of a spring tension element, which can be one of the elements 12,15,17,20 used in the construction of the extensible arms 8 and 9 of the first embodiment, or even a

  element of the arms in "V", which have just been described in variants.

  The telescopic element in question comprises, at one end, a first end piece 31 to which is linked a central metal rod 32, for example of steel, extending along the axis 33 of the element. At its opposite end, this element comprises a second end piece 34, to which is connected a metal tube 35, for example made of aluminum, which coaxially surrounds the rod 32 over a certain length, varying according to the degree of extension of

the telescopic element.

  A helical spring 36 is mounted and compressed in this element, the spring 36 being pressed by its ends against the two end pieces 31 and 34. This spring 36 surrounds the central rod 32 and is, itself, surrounded by the tube 35. However , the direct contact of the spring 36 with the central rod 32 and with the tube 35, metal parts, is prevented by a protective sheath of plastic 37 covering the rod 32, and by a protective internal coating 38 in plastic of the tube 35. A tubular cover 39, also made of plastic, is linked to the

  first end piece 31 and slides on the tube 35 linked to the second end piece 34.

  The two end pieces 31 and 34 can be provided with threads, respectively 40 and 41, for mounting the articulation parts such as ball joints, or even for fixing the central parts 14 and 19, in the

  case of elements intended for the arms in "X".

  In all cases, the extendable arms provide a permanent thrust on the load bar 5, tending to move this bar away from the winding tube 3 and therefore ensuring the tensioning of the fabric 1. These arms "follow" automatically the movements of the load bar, by modifying their length: - for the arms in "X" 8 and 9, figure 1 shows the deployed arms and figure 2 shows these folded arms; - for the "V" arms 22, 23, 27, 28 of FIGS. 3 to 5, the line drawing indicates the deployed position, and the line drawing

corresponds to the folded position.

  It should be noted that the tension-maintaining device according to the invention makes it possible to obtain a substantially constant tension of the fabric 1, in particular for positions of the load bar 5 comprised between a

  third and the whole of its stroke (from the folded position).

  It goes without saying that the invention is not limited to the sole embodiments of this tensioning device for sun protection fabric which have been described above, by way of examples; it embraces it, on the contrary all the variants of implementation and application respecting the same principle. Thus, one would not depart from the scope of the invention by modifications of detail of the telescopic tensioning elements, or even by the choice of a different overall configuration of the extendable arms, for example with two or more pairs of arms in "X". More particularly, variants can be envisaged for obtaining the spring effect of the extendable arms: the spring effect can be produced by at least one captive gas cylinder, constituting each arm or integrated into this arm; this spring effect can also result from at least one element subjected to a gas or liquid pressure supplied by an external source, such as a pump, providing a driving force for unwinding the fabric, the winding member of the canvas then made resistant to this driving force g

  thanks for example to a torsion spring.

Claims (11)

  1. Device for maintaining the tension of a sun protection fabric (1), deployed horizontally or with a slight inclination above a structure such as veranda, pergola, greenhouse or the like, having a frame (2), the fabric sun protection (1) having one end linked to a rotating winding member (3), preferably motorized, and its opposite end being linked to a movable load bar (5), comprising means for guiding in translation (6 , 7), characterized in that it comprises at least two extensible spring arms (8,9,22,23,27,28), each mounted in an articulated manner between a fixed point (13,18,24,29, 30) close to the winding member (3) of the fabric (1) and a movable point (16,21,25,26) linked to the load bar (5), so that these extendable arms, stressed by their springs (36) in the direction of their elongation, exert on the load bar (5) a push tending to move it away from the member winding (3) of the fabric (1).   2. Device for maintaining the tension of a sun protection fabric according to claim 1, characterized in that the extendable arms (8,9,22,23,27,28) are articulated at fixed points (13,18 , 24,29,30) which are points of the frame (11) supporting the winding member (3) of the fabric (1).   3. Device for maintaining the tension of a sun protection fabric according to claim 1 or 2, characterized in that it comprises at least two extensible spring arms (8,9) with an overall configuration in "X ", the two arms (8,9) crossing and being articulated between them (at 10) in their central parts (14,19), and being articulated each, by one end, at a fixed point (13,18) close of the winding member (3) of the fabric (1) and, by the other end, at a mobile point (16,21) linked to the load bar (5).   4. Device for maintaining the tension of a sun protection fabric according to claim 3, characterized in that each extendable arm (8,9) comprises a first telescopic tension element (12, 17) articulated at the fixed point (13 , 18) and connected, by an intermediate element (14,19) articulated (at 10) on the corresponding element of the other extensible arm, to a second telescopic tension element (15,20), articulated at the movable point   (16,21) linked to the load bar (5).   5. Device for maintaining the tension of a sun protection fabric according to claim 1 or 2, characterized in that it comprises at least two extensible spring arms (22,23,27,28) with a configuration of set in "V", each of the two arms being articulated, by one end, at a fixed point (24,29,30) close to the winding member (3) of the fabric (1) and, by the other end, at a mobile point (25,26) linked to the load bar (5).   6. Device for maintaining the tension of a sun protection fabric according to claim 5, characterized in that the extendable arms with a "V" configuration (22,23,27,28) each comprise a single element of telescopic tension.   7. Device for keeping a protective fabric in tension   solar according to any one of claims 3 to 6, characterized in   that it includes two or more pairs of arms that extend in an "X" (8,9) or in "V" (22,23,27,28).   8. Device for maintaining the tension of a sun protection fabric according to claim 4 or 6, characterized in that the or each telescopic tension element (12,15,17,20) of an extendable arm (8, 9, 22, 23, 27, 28) comprises a central rod (32) linked to a first end piece (31) provided at one end of the element, a tube (35) linked to a second end piece (34) located at the opposite end of the element, and a tubular cover (39) surrounding the central rod (32), linked to the first end piece (31) and sliding on the tube (35) linked to the second end piece (34), a helical spring ( 36) being mounted, with its ends pressed against the two end pieces (31,34),   around the central rod (32) and under the aforementioned tube (35).   9. Device for maintaining the tension of a sun protection fabric according to claim 8, characterized in that the central rod (32), metallic, is coated externally with a protective sheath (37) made of plastic, while the tube (35), also metallic, has an inner coating (38) of plastic, so that the turns of the   spring (36) come into contact with plastic parts.   10. Device for keeping a protective fabric in tension   solar according to any one of claims 1 to 7, characterized in   that the spring effect of the extendable arms is produced by at least one jack   gas captive, constituting each arm or integrated into this arm.   11. Device for keeping a protective fabric in tension   solar according to any one of claims 1 to 7, characterized in   that the spring effect of the extendable arms results from at least one element subjected to a gas or liquid pressure supplied by an external source providing a driving force for unwinding the fabric (1), the winding member ( 3) of the canvas being made resistant to this driving force   thanks for example to a torsion spring.