FR2875532A1 - Roller blind deploying and folding device for e.g. tertiary building, has pneumatic jack accumulating energy during prior folding of slides and restoring energy to deploy slides outwards when pawl is unlocked to pivot slides and case - Google Patents

Abstract

The device has a spring pawl (3) locking roller blind`s slides (22) in a vertical position. A liberation unit unlocks the pawl to pivot the slides and a case around a horizontal axis parallel to drum`s rotation axis. A folding unit (5) actuated by rolling of an apron (2) folds the slides. A pneumatic jack (4) accumulates energy during prior folding of the slides and restores the energy to deploy the slides outwards upon pawl unlocking.

Description

The present invention relates to a device for deploying and

  automatic folding of a shutter.

  This flap is intended to be placed in front of an opening in a building, an opening inside which is generally mounted a simple window or window.

  In a manner known per se, a roller shutter comprises an apron, a trunk, placed in the vicinity of the upper part of said opening, which makes it possible to store said apron in the wound state, around a drum, of the driving means for unrolling and winding said apron and a pair of vertical profiles, called slides, for guiding the two side edges of said apron.

  Roller shutters are closing devices that are more and more common, especially with regard to shutters or shutters.

  Their success is due to the fact that they are easy to maneuver, without the need to open the window and they can also be motorized with a fairly simple device, so affordable.

  Their success is also due to the fact that they can now be installed easily when renovating an existing building.

  A shutter constitutes both a closure device, intended to avoid possible intrusion inside a building, and a blind, intended to sift the external light.

  To benefit from a diffuse light, the rolling wheels were provided with perforated blades. However, this does not really allow you to see the outside.

  In addition, if this solution is adapted to modulate the illumination, it is not at all as regards the protection against the heat of the sun. Indeed, the rolling shutter deck, sometimes made of aluminum, behaves like a radiator that overheats the interior of the room and opposes the natural ventilation of the room. However, in times of high temperatures, it would be desirable to be able to ventilate the room.

  Furthermore, it is also known in the state of the art, a cloth awning type "banne", consisting of a wide web, placed above an opening of a building and can be unrolled or "projected" substantially horizontally or slightly inclined. Such a blind keeps the opening in the shade, while allowing excellent ventilation and keeping the view on the outside.

  The possible overheating of the fabric has no effect on the temperature of the room, since convection currents naturally refresh the unexposed side of the blind.

  This type of blind has the disadvantage of having a poor wind resistance. As soon as the wind becomes a little strong, it should be folded, because it is much more exposed than a vertical blind.

  It has therefore been envisaged to "deploy" the shutters, that is to say to tilt them outwards, with respect to the vertical, when they have descended, so as to combine the advantages of their good behavior. in the wind with those of the protection against heat.

  In the known devices of the state of the art, this function is obtained by making slides in two parts, an upper part, fixed, of short length and a lower part, much longer, articulated using a hinge at said upper part.

  In addition, the lower parts of the two slides are generally interconnected at their lower part, by a transverse bar. Compasses are mounted between the frame of the window and the lower end of each lower part of the slide.

  To deploy the deck, it is then pushed with both hands, then manually locks the compass located on each slide, one after the other.

  This operation is usually painful - the user can frequently pinch the fingers in the compasses - and can even be particularly dangerous, when it is done on windows located in floor, since the user risks being dragged into the vacuum leaning to maneuver said compass.

  In addition, it is impossible to wind the shutter as it is deployed, because interruptions of the slides at the hinges can lead to blockage, or even the destruction of the deck.

  Because of the aforementioned drawbacks, this type of shutter has steadily declined in the market in recent years.

  The new thermal regulation imposes the presence of solar protection on all types of buildings, residential and tertiary.

  Manufacturers would like to be able to continue to use the roller shutter, which has better wind resistance than canvas blinds and can provide a closing function. However, they are dissuaded by the fact that this type of product is poor sun protection and does not allow the ventilation of a room when closed.

  The object of the invention is to provide a roller shutter which can both function as a conventional roller shutter and which can also be deployed outwards and folded, and this, automatically, without any effort of the user, while being perfectly stable in the wind.

  To this end, the invention relates to a device for automatic deployment and folding of a roller shutter, intended to be placed in front of an opening of a building, this flap comprising an apron, a chest, placed in the vicinity of the upper part of said opening, which makes it possible to store said apron in the wound state, around a drum, motor means for unrolling and winding said apron and a pair of vertical sections, called "slides", for guiding the two lateral edges of said apron.

  According to the invention, the slides are adapted to pivot about a horizontal axis, parallel to the axis of rotation of the drum, so as to allow the deployment of said slides to the outside, to tilt relative to the vertical and the device comprises: a locking member for said slides in vertical position, means for releasing said locking member, means for folding the slides actuated by the winding of the apron, and means for automatically deploying said slides. , able to accumulate energy during the previous folding of the slides and to restore it to automatically deploy said slides, upon release of the locking member.

  In the remainder of the description and the claims, the term "deployment" means that the apron and the wings are inclined towards the outside of the building, with respect to the vertical, their lower parts being separated from the building while their upper parts are are close.

  According to other advantageous and nonlimiting features of the invention, taken alone or in combination: the upper ends of the slides are integral with the box, so that the assembly can pivot in a block around a horizontal axis, parallel to the axis of rotation of the drum; the horizontal pivot axis coincides with the axis of rotation of the drum; - The automatic deployment means consist of at least one pneumatic cylinder called "gas spring" whose body is secured to a fixed point of the opening and whose rod is integral with one of the slides or an element linked to these slides, for example a lower horizontal transverse bar, or vice versa; the automatic deployment means consist of at least one incorporated spring-loaded pivoting arm; the means for folding the slides comprise a strap and at least one deflection pulley fixed for example on the lower part of one of the slides and said strap is secured to one of its ends of the lower part of the apron and at its opposite end of a fixed point located in the vicinity of said opening O and passes around said pulley, so that the winding of the deck, while the wings are deployed, causes traction on said strap and via the pulley of return, folding the slides towards the opening O (the return pulley is not necessarily attached to the lower part of one of the slides, it may be located at another location along the slide); - The folding means further comprises retraction means of said strap secured to a fixed point in the vicinity of said opening O, and an end stop, secured to a fixed point in the vicinity of said opening O, intended to limit the displacement of said retraction means, and in that the strap is connected to said retraction means, so that the winding of the apron, while the slides are deployed, causes a pull on said strap, the coming retraction means at the end of stroke against the stop, and via the return pulley, the folding of the corresponding slide towards the opening O; the retraction means are a helical coil spring extending substantially vertically; - The height position of the end stop (540) is adjustable; the means for folding the slides comprise a strap and at least one return pulley, fixed, for example on the lower part of one of the slides, said strap is secured at one of its ends to a fixed point located in the vicinity of said opening O and at its opposite end of a slider, able to slide inside one of the slides, this strap passing around said pulley and the lower part of the deck is provided with a latching member, adapted to drive the slider during the winding of the apron, so that the winding of the apron, while the slides are deployed, causes traction on said strap and via the pulley, the folding of the corresponding slide in the direction of the opening O; the strap passes around a plurality of return pulleys; - The release means of the slide locking member are manually operated; the means for releasing the slide locking member are automatically actuated by the last blade of the apron; the motor means are an electric motor driving the rotation of the drum.

  Other features and advantages of the invention will appear from the description which will now be made, with reference to the accompanying drawings, which represent, by way of indication but not limitation, possible embodiments.

  In these drawings: FIGS. 1A to 1D are diagrammatic views, in vertical cross section, of the window of a building, equipped with a shutter according to the invention, representing various successive stages of unfolding, deployment, winding and folding the apron of said shutter, - Figures 2A to 2F are views similar to Figures 1A to IF, 25 which show an alternative embodiment of the deployment means of the slides, - Figures 3A to 3C are diagrams representing a second embodiment of the slide-back means, and - Figures 4, 5 and 6 are diagrams showing alternative embodiments of the hauls of the automatic slide-back means illustrated in Figures 1A-IF.

  In Figures 1A and 1B, we can see a roller shutter according to the invention, disposed in front of an opening O, pierced inside the walls M of a building.

  A window comprising a window V, fixed in an OR opening and surrounded by a frame D, is sealed inside the opening O. The shutter comprises a box 1 and an apron 2.

  The trunk 1 is mounted between two consoles 11, themselves fixed to the wall M. A single console is visible in the figures.

  This box contains a drum (not visible in the figures) around which the apron 2 can be wound. The trunk is used to protect the deck from the weather. The axis of rotation of the drum which extends horizontally, parallel to the plane of the opening O, carries the reference 12.

  The trunk 1 is mounted between the brackets 11, so as to be pivotable about the axis 12, (see Figure 1C).

  The apron 2 consists of a plurality of parallel blades 21, assembled, the last, that is to say the one at its lower end is referenced 210.

  The shutter also comprises two vertical profiles 22, called "slides", which serve to guide the two side edges of the deck 2. A single slide 15 is visible in the figures.

  The lower end of the slides bears the reference numeral 222. The upper end 221 of each slide 22 is fixed to the chest 1, so that the slides 22 are integral with it.

  Accordingly, the pivoting of the trunk 1 about the axis 12, in the clockwise direction in FIG. 1C, causes the slides 22 to be deployed outwards.

  According to an alternative embodiment not shown in the figures, the set chest 1 / slides 22 can also rotate about a horizontal axis, parallel to the axis 12 and close to it.

  Motor means, not shown in the figures, can unwind or wind the deck 2, to lower it, respectively up between the two slides 22.

  Advantageously, these motor means are constituted by an electric motor, mounted for example on one end of the axis 12, the latter then constitutes a drive shaft.

  However, manual operation of the deck 2, using a crank may also be considered.

  A locking member 3 keeps the slides 22 in a vertical position called "rest", that is to say not deployed.

  This locking member is for example a spring pawl, as shown in the figures.

  This pawl 3 is pivotally mounted about an axis integral with a fixed point of the opening, for example the frame D of the window.

  In the locked position, illustrated in FIG. 1A, the penne 30 of the pawl 3 penetrates into the base of the lower end 222 of the slide 22.

  In the unlocked position, illustrated in FIG. 1B, the pawl 3 has rotated angularly, so that its penne 30 has left the end of the slide 22.

  According to an alternative embodiment not shown in the figures, the two slides 22 may be connected at their respective lower ends 222, by a horizontal cross member. The locking member 3 can then be placed in the center of the window, to act in the center of this cross and lock it. It is also possible to have two locking members, located on either side of the center of the cross.

  The unlocking of the pawl 3 is effected by means of release which can be manual or automatic.

  When they are manual, they are preferably arranged so that they can be operated only from inside the building, to avoid any risk of burglary. The pawl 3 which retains the link connecting the slides is out of the field of the deck 2. It is sufficient to manually press the pawl 3 to release the crossbar.

  The automatic release means will be described later.

  A first embodiment of the automatic deployment means slides 22, shown in Figures 1A to 1 F consists of a pneumatic cylinder 4 or "gas spring".

  This jack comprises a body 41 and a rod 42. The rear end 410 of the body 41 is fixed on a fixed point located in the vicinity of the opening O. The head 420 of the rod 42 is fixed on the slide 22, in one point located on the lower part thereof, and at a lower height at which the end 410 is fixed on the wall. When the slides 22 are deployed, the jack 4 is thus inclined in the same direction as the slides.

  This jack could of course be fixed upside down, so that its rod 42 is integral with the building and its body 41 is integral with the slides 22.

  Preferably, there is provided a jack 4 for each slide 22. In the case where the slides 22 are connected in the lower part by a cross member, a single jack 4 could be used.

  Finally, the pneumatic cylinder 4 could be replaced by a spring cylinder.

  As illustrated in FIG. 1C, the means 5 for folding the slides 22 comprise a strap 51, means 52 for retracting this strap, two reference pulleys referenced 55 and 56, and a limit stop 540.

  Advantageously, and to balance the forces exerted on the slides 22, folding means 5 are associated with each slide 22.

  The retraction means 52 are here constituted by a helical coil spring which extends substantially vertically, parallel to the window.

  Its upper end 522 is fixed to a fastener 53 secured to a fixed point of the upper part of the opening O. Its lower end 521 is provided with a ring 54, to which one of the ends, referenced 512, of the strap 51 is fixed.

  The other end 511 of the strap is fixed on the last blade 210 or one of the last blades of the apron 2.

  The strap 51 passes around the first deflection pulley 55, fixed on the lower part 222 of the slide 22 and around the second deflection pulley 56, which is secured to a fixed point of the lower part of the O opening of the building.

  Finally, the strap 51 passes through the abutment 540, consisting of a tab pierced with an orifice 541. The dimensions of this orifice 541 allow the passage of the strap 51 and not that of the ring 54.

  According to an alternative embodiment not shown in the figures, the position of the limit stop 540 can be adjustable in height.

  Other alternative embodiments of the folding means 5, not shown in the figures, consist for example of replacing the strap 51, by a cord or the coil spring 52, by an elastic or a winding member of the strap.

  Finally, if the retraction means 52, the stop 540 and the pulley 56 are advantageous in that they prevent the strap 51 from hanging out of the window, when the deck 2 is unwound, they are not mandatory .

  The operation of the device will now be explained in more detail.

  In the initial position, illustrated in FIG. 1A, the apron is completely wound inside the trunk 1, so that only the last blade 210 is seen. The slides 22 are immobilized vertically by the pawl 3.

  The strap 51 whose end 511 is integral with the last blade 210 extends inside the slide 22. The retraction spring 52 of the strap 51 is here completely deployed, so that the ring 54 comes into contact of the end stop 540.

  Finally, the pneumatic cylinder 4 is in the folded position.

  According to a first mode of use of the shutter, the electric motor is actuated so as to lower the deck 2 between the two slides 22, to reach a low position, in which it does not exert pressure on the penne 30 of the pawl 3.

  In this position, the spring 52 retracts by pulling on the strap 51, so that it extends parallel to the deck 2, along the 15 amounts of the window, as shown in Figure I B. Thus , the strap 51 does not hang outside the window.

  When the user wishes to deploy the shutter, it actuates the electric motor, so as to completely unroll the deck 2, as shown in Figure 1B. The last blade 210 then exerts pressure on the pin 30 of the pawl 3, which has the effect of pivoting the latter and release the slides 22. The latter can then rotate freely around the axis 12 of the box.

  The gas (nitrogen for example), compressed inside the body 41 of the pneumatic cylinder 4 can then relax and exert a thrust on the rod 42. The latter exits the body by pivoting the slides 22, to the extreme deployed position (projection position), shown in Figure 1C.

  The strap 51 secured to the apron 2 then exerts traction on the spring 52 by partially relaxing it, so that the strap follows the slide 22 without exerting stress on the jack 4.

  This extreme deployment position is particularly stable.

  Under the pressure of the wind, the pneumatic cylinder 4 resists in traction, because its rod 42 is completely out, and it also dampens any jolts in case of compression of said rod.

  It is also possible to provide, on the consoles 11, a device for limiting the angular displacement of the trunk 1.

  When the user wishes to automatically fold the slides 22, he actuates the motor in the upward direction of the apron 2. The apron wraps around the drum and its last blade 210 then exerts a pull on the strap 51, which which has the effect of lengthening the spring 52.

  The resistance of the pneumatic cylinder 4 to the folding of the slides 22 is greater than that of the spring 52, so that the deck 2 continues to wind without pivoting, as long as the ring 54 does not come into contact with the stop 540, (see figure ID).

  As can be seen in Figure 1 E, when the ring 54 of the spring 52 comes into contact with the stop 540, any additional upward movement of the last blade 210 of the apron exerts a pull on the strap 51. The - C can not lie, the traction force of the deck 2, taken by the pulley 55, causes the pivoting of the wings 22 about the axis 12.

  The folding of the slides 22 exerts a pressure on the rod 42 of the cylinder 4, which has the effect of compressing the gas present inside the body 41.

  When the last blade 210 reaches the high position, as illustrated in FIG. 1F, the entire strap 51 has been pulled into the slide 22. The spring pawl 3 then automatically resumes its locking position of the slides 22.

  The ratchet 3 then opposes an inadvertent projection flap from the outside. To do this, the ratchet is made inaccessible from the outside.

  The device according to the invention therefore consists in fully utilizing the power of the electric motor, which is exerted via the traction of the apron 2, to arm the jack 4, during the folding of the slides.

  This cylinder accumulates energy, which it will later restore to automatically deploy the slides 22, as soon as they are released and without any effort on the part of the user.

  In addition, simultaneously rotate the chest 1 and the slides 22, removing the hinges used in the state of the art, eliminates any risk of jamming the deck to the right of its hinges.

  Note however that according to an alternative embodiment according to the present invention, the slides can be hinged at their upper part on the trunk, the latter remaining fixed, or the slides can be articulated relative to the wall.

  The embodiment just described here is of course only one example and other variants will now be described which are based on the same operating principle.

  FIGS. 2A to 2F illustrate an alternative embodiment of the means for automatic deployment of the slides in which the pneumatic jack 4 is replaced by a pivoting arm 6 with at least one incorporated spring.

  The other parts of the device are identical and bear the same numerical references.

  In these figures, the device for folding the slides has not been shown for simplification purposes, but is identical to that shown in FIGS. 1A to 1F.

  The pivoting arm 6 is for example of the type of those used in blinds blinds or blinds projection to the Italian.

  It comprises a body 60, one of the ends 62 is integral with a fixed point located in the vicinity of the lower portion of the opening O, for example the lower frame of the window.

  Its opposite end 61 is slidably mounted on the inner face 223 of the slide 22, that is to say the face facing the opening O. The body 60 further has at least at its end 61 and preferably both, two torsion springs, of the spiral spring type (not visible in the figures).

  These two torsion springs, when compressed, tend permanently to pivot the arm 6 to bring it from the vertical position shown in Figure 2B to the position close to the horizontal shown in Figure 2C.

  Consequently, when the pawl 3 is unlocked, the end 61 of the arm 6 is forced to move downwards along the inner face 223 of the slides 22.

  Conversely, when the slide 22 is folded, the end 61 of the arm 6 slides upwards (see Figure 2D) to return to its original position shown in Figure 2E.

  The winding of the apron 2 therefore has the effect of rearming the springs of the arm 6, which thus accumulate energy. These springs will release this energy by relaxing during the next slide deployment.

  FIGS. 4 to 6 illustrate alternative embodiments of the means 5 for folding the slides, which consist in replacing the return pulleys 55 and 56 by a haul or set of pulleys which make it possible to reduce the traction exerted by the upward movement of the apron .

  The elements identical to those shown in FIGS. 1A to 1F bear the same reference numerals.

  The system illustrated in FIG. 4 differs from that of FIG. 1 in that an additional idler pulley 57 is attached to the lower end of the tension spring 52. The strap 51 passes through this pulley 57 between the pulleys 55 and 56. The pulley 57 can also come into contact with the abutment 540 during the expansion of the spring 52.

  FIG. 5 differs from FIG. 1 in that an additional return pulley 58, integral with the wall of the building, is placed in the path of the strap 51 between the pulleys 55 and 56.

  The device of FIG. 6 differs from the device of FIG. 5 in that an additional return pulley 59 is fixed to the end of the last leaf 210 of the apron and in that the end 511 of the strap 51 is attached to the end 222 of the slide 22. The strap 51 thus passes successively the pulleys 59, 55, 58 and 56.

  FIGS. 3A to 3C schematically illustrate a second embodiment of the means for folding the slides 22.

  The folding means 7 comprise only a strap 71 and no longer include the retraction means of Figure 1. A return pulley 75 is attached to the lower end 222 of the slide or on a member connected thereto.

  The last blade 210 of the apron 2 is provided with a tip 211 whose dimensions allow it to slide inside the slides 22.

  The strap 71 is attached at one of its ends 712 to the wall M and at its opposite end 711 to a slider 72.

  The shape of the slider 72 prevents it by adherence to the profile of the slider 22, from falling under its own weight.

  In the starting position illustrated in Figure 3A, the deck 2 is fully raised and the nozzle 211 engages the slider 21 which is in the up position.

  In FIG. 3B, the apron 2 is completely unrolled, the slide 22 is in the locked position and the slider 72 remains in the high position, because it is held by friction inside the slide 22, or any equivalent means such as a support which limits the race, an elastic indexing, etc ...

  In FIG. 3C, the automatic deployment means authorized the deployment of the slides 22.

  The end 712 of the strap being integral with the wall M, the movement of deployment of the slide has the effect of exerting traction on the strap 71 and cause the descent of the slider 72. The latter does not go down further because it is in friction inside the slide 22 or has reached a stop on a fixed limit of travel obstacle or indexing (for example magnetic).

  When the apron 2 is reassembled, the nozzle 211 moves upwardly within the wings 22 until it comes into contact with the slider 72 that leads in its race.

  The end 712 of the strap being fixed, this has the effect of causing the folding of the slide 22.

Claims (17)

  1. Device for the automatic deployment and folding of a shutter, intended to be placed in front of an opening (0) of a building, this shutter comprising an apron (2), a trunk (1), placed in the vicinity of the part upper of said opening, which makes it possible to store said apron (2) in the wound state, around a drum, motor means for unrolling and winding said apron (2) and a pair of vertical profiles (22), said " slides "for guiding the two lateral edges of said apron (2), this device being characterized in that the slides are adapted to pivot about a horizontal axis, parallel to the axis of rotation (12) of the drum, of in such a way as to allow said slides (22) to extend outwards, to incline them with respect to the vertical and in that it comprises: at least one locking member (3) of said slides (22) in a vertical position, means for releasing said locking member, yens (5, 7) for folding the slides, actuated by the winding of the apron (2), - means (4, 6) for automatic deployment of said slides, able to accumulate energy during the previous folding backstage (22) and to restore it to automatically deploy the slides, upon release of the locking member (3).   2. Device according to claim 1, characterized in that the upper ends (221) of the slides are integral with the trunk (1), so that the assembly can rotate in a block around a horizontal axis, parallel to the axis rotation of the drum.   3. Device according to claim 1 characterized in that the slides (22) are articulated on the trunk (1) in the vicinity of their upper end.   4. Device according to claim 1, characterized in that the slides (22) are articulated relative to the wall.   5. Device according to one of claims 1 to 4, characterized in that the horizontal pivot axis of the slides coincides with the axis of rotation (12) of the drum.   6. Device according to claim 1 to 5, characterized in that the automatic deployment means consist of at least one pneumatic cylinder (4) whose body (41) is secured to a fixed point in the vicinity of the opening (0) and whose rod (42) is integral with one of the slides (22) or vice versa.   7. Device according to claim 1 to 5, characterized in that the automatic deployment means consist of at least one pivoting arm (6) with at least one incorporated spring.   8. Device according to one of the preceding claims, characterized in that the means (5) for folding the slides (22) comprises a strap or the like (cord, cable, ...) (51) and at least one pulley referral (55), fixed on the lower part (222) of one of the slides (22) and in that said strap (51) is integral with one of its ends (511) of the lower part (210) of the apron (2) and at its opposite end (512) a fixed point located in the vicinity of said opening (0) and passes around said pulley (55), so that the winding of the deck (2), then that the slides (22) are deployed, causes traction on said strap (51) and via the return pulley (55), the folding of the corresponding slide (22) towards the opening (0).   9. Device according to claim 8, characterized in that the folding means (5) further comprises means (52) for retraction of said strap (51) integral with a fixed point located in the vicinity of said opening (0). ), and a limit stop (540), integral with a fixed point situated in the vicinity of said opening (0), intended to limit the displacement of said retraction means (52), and in that the strap (51) ) is connected to said retraction means (52), so that the winding of the apron (2), while the slides (22) are deployed, causes a pull on said strap (51), the arrival of the retraction means ( 52) at the end of the stroke against the stop (540), and via the return pulley (55), the folding of the corresponding slide (22) in the direction of the opening (0).   10. Device according to claim 9, characterized in that the retraction means (52) are a helical coil spring extending substantially vertically.   11. Device according to claim 9 or 10, characterized in that the height position of the end stop (540) is adjustable.   12. Device according to any one of claims 1 to 7, characterized in that the folding means (7) of the slides comprises a strap (71) and at least one return pulley (75), fixed on the lower part ( 222) of one of the slides (22), in that said strap (71) is integral at one of its ends (711) with a fixed point situated in the vicinity of said opening (0) and at its end opposed (711) of a slider (72), slidable inside one of the slides (22), this strap passing around said return pulley (75) and in that the lower part (210) ) of the apron is provided with a fastening member (211), able to drive the slider (72) during the winding of the deck (2), so that the winding of the deck (2), while the slides (22) are deployed, causes traction on said strap (71) and via the return pulley (75), folding the corresponding slide (22) towards the opening (0). ).   13. Device according to claim 12, characterized in that it comprises means, for example friction, travel limit stop or magnetic indexing, braking or limiting free movement of the slider (72) downwards.   14. Device according to any one of claims 8 to 11, characterized in that the strap (51, 71) passes around a plurality of return pulleys (55, 56, 57, 58, 59, 75).   15. Device according to one of the preceding claims, characterized in that the release means of the locking member (3) of the slides are operated manually.   16. Device according to one of claims 1 to 14, characterized in that the means for releasing the locking member (3) of the slides are actuated automatically by the last blade (210) of the deck (2).   17. Device according to one of the preceding claims, characterized in that the motor means are an electric motor driving the rotation of the drum.