FR3084691A1 - SCREEN DRIVE SYSTEM AND CLOSURE OR SUN PROTECTION SYSTEM COMPRISING SUCH A SYSTEM - Google Patents

Abstract

In this system for driving a mobile screen in a closing or sun protection installation comprising a winding tube itself mobile in rotation about an axis of rotation (X-X '), a tubular electromechanical actuator of the winding tube drive is housed in the winding tube and comprises a housing (L26) for receiving at least two batteries (262) intended for supplying an electric motor to the tubular electromechanical actuator . An axial clearance take-up mechanism (100) is disposed in the receiving housing (L26) and comprises a support (102) mounted in the receiving housing (L26), a piston (104), sliding relative to the support according to a sliding axis (A100) parallel to a longitudinal axis (A26) of the receiving housing, being guided by the support, and which is equipped with a member (110) for electrical contact with a terminal (264) of a battery (262) adjacent. The axial clearance take-up mechanism (100) also comprises a helical spring (120) interposed axially between the support (102) and the piston (104) and which exerts on the piston an elastic return force (E120) towards the adjacent battery (262).

Description

Screen drive system and closing or sun protection installation comprising such a system

The present invention relates to a system for driving a mobile screen in a closing or sun protection installation, as well as a closing or sun protection installation including, among others, such a driving system.

In known manner, a closing or sun protection installation comprises a screen that can be moved between two so-called end-of-travel positions, in particular a roll-up screen, such as a flexible apron, for example an apron formed by blades hinged together or by a blind canvas. Such an installation conventionally comprises a winding tube on which is fixed and wound the rollable screen or on which is wound a cord or a lace integral with this screen. Such an installation further comprises an electromechanical actuator which includes, among other things, an electric motor and which is designed to drive the winding tube in rotation in order to deploy or fold the screen according to the wishes of a user.

In some installations, it is possible to power the electric motor of the actuator from the mains, which is achieved by means of a conductive cable which runs to the actuator. In other installations, in particular in the event of renovation, the actuator must be able to function independently, without being connected to the mains. In this case, it is known from FR-A-3 059 657 or from EP-A-3 219 888 to use one or more batteries making it possible to supply the electric motor of the electromechanical actuator without the need to connect to the area.

In this type of installation, a stack of batteries is made, which makes it possible to deliver to the electric motor of the actuator a voltage equal to the sum of the voltages of these different batteries. Thus, it is not uncommon to have, one behind the other, eight or more batteries, inside a housing formed by a casing of a tubular electromechanical actuator or a winding tube.

Given the manufacturing tolerances of the batteries and the actuator housing, the length of such a stack is variable, as is the length of the battery receiving housing, to the point that there is a risk of electrical contact, for example between, on the one hand, positive or negative terminals of the two batteries disposed at the two ends of the stack and, on the other hand, pads connected to electrically conductive cables intended for the supply of an electric motor of the actuator or of an associated electronic unit There is possibly a fault in electrical contact between two batteries themselves.

The use of an elastically deformable tab at one of the contact pads, or even of these two contact pads, does not allow these relatively large dimensional variations which result from the addition of the manufacturing tolerances of the batteries to be absorbed. and manufacturing tolerances for the actuator housing.

It is to these drawbacks that the invention more particularly intends to remedy by proposing a new drive system for a mobile screen within a locking or sun protection installation, in which a stack of batteries disposed at the inside a housing provided for this purpose in a tubular electromechanical actuator is in permanent electrical contact with the rest of a current supply circuit of an electric motor or of an electronic card of this actuator.

To this end, the invention relates to a system for driving a mobile screen in a closing or sun protection installation, this system comprising a winding tube for the mobile screen, itself mobile in rotation around 'an axis of rotation, as well as a tubular electromechanical actuator for driving the winding tube, this actuator being housed in the winding tube. A housing is provided for the reception of at least two batteries intended for the supply of an electric motor of this tubular electromechanical actuator. According to the invention, an axial clearance take-up mechanism is arranged in the receiving housing. In addition, this backlash mechanism comprises a support mounted in the receiving housing and a piston, sliding relative to the support along a sliding axis parallel to a longitudinal axis of this housing, being guided by the support. This piston is equipped with an electrical contact member with an adjacent battery terminal. A helical spring is interposed axially, along the sliding axis of the piston, between the support and the piston and exerts, on the piston, an elastic return force towards the adjacent battery.

Thanks to the invention, the backlash mechanism arranged, preferably, in the vicinity of the bottom of the battery receiving housing makes it possible to compensate for dimensional variations in the stack of batteries disposed in this housing thanks to the piston which, under the 'effect of the elastic force exerted by the helical spring, remains pressed against the terminal closest to the adjacent battery. The backlash mechanism of the drive system of the invention makes it possible to compensate for dimensional variations in the stack of batteries greater than or equal to 12 millimeters (mm), or even 15 mm, which would not be possible with a simple elastic tab forming an electrical contact in the vicinity of the bottom of the battery receiving housing.

According to advantageous but not compulsory aspects of the invention, such a training system can incorporate one or more of the following characteristics, taken in any technically admissible combination:

- The piston supports a printed circuit board, which carries the electrical contact member and an electrical connector for connection of at least one conductive cable.

- Each conductive cable connected to the electrical connector is wound at least 180 ° around the sliding axis of the piston.

- The support is provided with a peripheral skirt defining a housing for receiving a portion of at least one conductive cable connected to the printed circuit board and wound around the sliding axis of the piston.

- The piston includes fastening members for the printed circuit board in a configuration where this card is perpendicular to the sliding axis of the piston.

- The support includes a rotation blocking relief, around a longitudinal axis of the receiving housing, inside this housing.

- The piston comprises a rod engaged in a through hole of the support and the helical spring is arranged around this rod, in axial abutment against, on the one hand, the support and, on the other hand, the piston.

- The piston rod is provided with latching reliefs in the through hole of the support and these reliefs form means for temporarily retaining the helical spring on this rod during assembly of the play take-up mechanism.

- The support and the piston are each provided with a peripheral skirt and the two skirts together delimit, radially outwards relative to the longitudinal axis, a housing for receiving the helical spring.

According to another aspect, the invention relates to a closing or sun protection installation which comprises a mobile screen by winding on a winding tube, as well as a drive system as mentioned above.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of an embodiment of a drive system and of a sun protection installation in accordance with its principle, given solely by way of example and made with reference to the appended drawings in which:

- Figure 1 is a schematic axial section in principle of a sun protection installation according to the invention;

- Figure 2 is a partial view on a larger scale of the interior of a battery receiving housing belonging to the installation of Figure 1, this view showing, among other things, a backlash device in a first configuration;

- Figure 3 is a perspective view of the play take-up device at a first angle;

- Figure 4 is a perspective view of the same backlash device at a second angle;

- Figure 5 is a perspective view of the same backlash device at a third angle;

- Figures 6 and 7 are respectively sections in perspective along the planes VI and VII in Figure 5;

- Figure 8 is an axial section corresponding to detail VIII in Figure 2;

- Figure 9 is an axial section similar to Figure 8, when the backlash device is in a second configuration;

- Figure 10 is a perspective view similar to Figure 5, when the backlash device is in the second configuration; and

- Figure 11 is a section similar to Figure 1 of an installation according to a second embodiment of the invention.

FIG. 1 represents a system 1 for driving a screen 6 forming a roller blind mounted in the upper part of an opening O of a door or window of a building. This drive system 1 is part of a sun protection installation 200 which comprises, in addition to the drive system 1 and the screen 6, a box or trunk 4 inside which the drive system 1 is installed. .

The screen can be formed by a canvas or a set of blades hinged together. In the case of the application of the invention to a locking installation, the screen can be a grid.

The drive system 1 comprises an actuator 3 and a winding tube 5, movable in rotation about an axis XX ′ which is horizontal in the mounted configuration of the installation 200 and which constitutes a longitudinal axis for the tube 5. The axis X-X 'is a central axis or a reference axis of the drive system 1. In the following, unless otherwise stated, the terms "axial >> and" radial >> are used with reference to this central axis XX ′ or to an axis coincident therewith.

In this exemplary embodiment, the drive system 1 also comprises a compensation spring 7 making it possible to partially compensate for the torque exerted by the weight of the screen 6. This is not however compulsory.

The actuator 3 is mounted at least partially inside the winding tube 5 and drives the latter in rotation about the axis XX ′ by means of a connecting piece 34 called “wheel d 'training'. The winding tube 5 is mounted with the possibility of rotation in the trunk 4 by means of two rings 42 and 44 forming bearings each arranged in the vicinity of one end of this winding tube. The actuator 3 extends along the central axis X-X 'and comprises a casing or tubular casing 30. Inside this tubular casing are housed a supply assembly 26, comprising eight accumulator batteries 262 arranged one behind the other along the axis XX ', an electronic control unit 31, an electric motor 33, as well as a reduction gear and a brake not shown and which are optional. The batteries 262 are, for example, of the LR14 type.

As a variant, the casing 30 can be bipartite and the supply assembly 26 can be housed in a first part of the tubular casing connected by a bundle of conductive wires to a second part of the tubular casing 30 in which the electronic circuit board is located. steering 31 and the electric motor 33.

The electric motor 33 is preferably a direct current motor and has a stator 37 fixed relative to the casing 30 and a rotor 38 which drives, via the reduction gear, an output shaft 32. This output shaft drives itself the winding tube 5 by means of the drive wheel 34 which is fixed in rotation both on the output shaft 32 and on the winding tube 5. The electronic control unit 31 ensures the operation of the electric motor 33 by relating, according to the movement orders received, for example from a remote control 70, the power supply unit 26 and the electric motor 33.

The actuator 3 comprises a head 36 which projects outside the winding tube 5. The head 36, which can also be described as a “fixed point”, consists of two ears intended to cooperate with reliefs of shapes corresponding formed on a support 46 fixed inside the box 4. Thus, the head 36 allows to support the actuator 3 and the winding tube 5 on the side of the support 46. The head 36 also allows a recovery torque at the output of actuator 3. This is why it can be qualified as a “fixed point” for this actuator.

Note 52 the end of the winding tube facing the support 46. Note 54 the opposite end of the winding tube 5.

The head 36 is provided on the side of the end 52.

On the side of the end 54, a shaft 40 connects an internal part of the ring 44 with the box 4, in order to support the winding tube 5 in the box 4.

The ring 42 forming a bearing on the end side 52 comprises a cylindrical part at least partially surrounding the casing 30 and / or the head 36 and a flange 56, which closes the radial space which exists between this tube 5 and the casing 30 of the actuator 3. Note 30a the part of the casing 30 which defines a housing L26 in which the different batteries 262 are disposed within the supply assembly 26. Here, the part 30a is in one piece, or at all the least rigidly linked, with the part of the casing 30 which surrounds the components 31 and 33.

In the example, the power supply 26 comprises eight batteries 262. This number is not, however, limiting. The number of batteries must only be greater than or equal to two, and for example equal to twelve, the maximum number of batteries being limited by the maximum length desired for the actuator 3. The type and number of batteries is determined according to the desired supply voltage for the electric motor 33.

As shown in FIG. 2, the housing L26 extends along a longitudinal axis A26 which coincides with the axis XX 'in the assembled configuration of the installation 200. This housing L26 extends between an opening 026 which is closed by a hatch 27 and a bottom F26 which defines the end of the housing L26 opposite the opening 026.

According to the invention, a backlash mechanism 100, parallel to the axis A26, is arranged in the vicinity of the bottom F26, being designed to receive, in support, a positive terminal 264 of a battery 262 which is the battery furthest from opening 026 within the battery stack disposed in the housing L26.

For clarity of the drawing, in FIGS. 2, 8 and 9, the batteries 262 are shown in center lines, by the trace of their respective envelopes.

The backlash mechanism 100 includes a support 102 and a piston 104, this piston supporting a printed circuit board 106. A100 denotes a longitudinal axis of the backlash mechanism 100 which coincides with the axis A26 when the mechanism play take-up 100 is mounted in the receiving housing L26. The piston 104 is movable relative to the support 102 in translation along the axis A100.

As a variant, the axes A26 and A100 may be parallel but not confused, due in particular to the presence of a battery support or the need to pass electrical conductors, in particular of the antenna or cable type, parallel to the batteries.

On the face 108 of the printed circuit board 106 opposite the support 102, this printed circuit board is provided with a pad 110 of electrical contact with the positive terminal 264 of the adjacent battery 262. This stud forms an additional thickness on the printed circuit, visible in FIG. 2.

On its face 112 opposite the face 110, the printed circuit board 106 carries a connector 114, electrically connected to the pad 110 and to which one or more conductive cables are connected, allowing, on the one hand, to connect the pad 110 to the motor electric 33 and / or to the electronic card 31 and possibly, on the other hand, to supply electronic components not shown, also supported by the electronic card 106 and which for example have a safety function to avoid damage to the card electronic 31 in case of reverse positioning of the batteries. As a variant or in addition, one or more conductive cables can also be soldered to the printed circuit board 106.

The direction of connection of the conductive cable (s) to the connector 114 is as shown by the arrow F2 in FIG. 4, that is to say parallel to the face 112 so that the conductive cable (s) can be wound up around the central axis A100 of the play take-up mechanism 100 over at least 180 °, preferably over at least 360 °, before changing direction passed within the support 102, through holes not shown, to come out of it by its visible side in Figure 5, at least for some of them. The path of this or these cables, which are not visible as such, is represented by the thick axis lines 116, only in FIGS. 3 to 5.

The support 102 is immobilized in the part 30a of the casing 30, in the vicinity of the bottom F26 of the housing L26 by aligning the axis A100 with the axis A26. To do this, the support 102 is equipped, on its external peripheral surface 1022, with several gadroons or ribs 1024 which participate in the wedging of the support 102 in the housing L26. Alternatively, the gadroons 1024 can be omitted.

The support 102 is also provided with a notch 1026 formed in a parallelepipedic block 1028 and which is intended to cooperate with a fixing means such as a screw or a rivet, to immobilize the support 102 relative to the part of the housing 30 defining the housing L26. A localized excess thickness 1024a of the support 102 cooperates with a corresponding housing of the casing 30, which is not shown, to immobilize the support in rotation around the axes A26 and A100 combined in the housing L26.

As a variant, the block 1028 can be full, that is to say without a notch 1026.

The support 102 comprises an axial wall 1030, that is to say perpendicular to the axis A100, in which is formed an opening 1031 centered on this axis. The support 102 also comprises an internal skirt 1032 of annular shape and centered on the axis A100, as well as an external skirt 1034 which surrounds the skirt 1032 at a distance therefrom, from a heel 1036, and in s 'moving away from this heel to beyond the axial wall 1030. An annular space E102 is defined by the support 102, between the skirts 1032 and 1034, radially to the axis A100. This annular space E102 makes it possible to limit the radial thickness of the constituent parts of the support 102 and to better control its geometry.

The support 1032 also comprises a second skirt 1038 which extends, opposite the skirt 1034 relative to the heel 1036, at an axial distance from the skirt 1032 so that a housing L102 is defined radially between the skirts 1032 and 1038, on the side of the heel 1036 opposite the skirt 1034, this housing being open in the direction of the printed circuit board 106 when the support 1032 is assembled to the piston 104. This housing L102 makes it possible to receive the cable or cables connected to the connector 114 and which are wound around the axis A100, as mentioned above, in particular to prevent them from being pinched during the sliding of the piston 104 relative to the support 1032.

The support 102 is formed by a single piece of synthetic material.

The piston 104 is, in turn, made up of three parts, namely a rod 1042 and a sleeve 1044 made of synthetic material, as well as a metal or synthetic screw for assembling parts 1042 and 1044 therebetween.

The synthetic material used to manufacture parts 102, 1042 and 1044, or even 1046, is, for example, polyamide 6-6.

The rod 1042 comprises two tabs 1042a and 1042b engaged in the opening 1031 and separated by a slot 1042c. Each tongue 1042a and 1042b is provided with an external hook 1042d of generally triangular section which prevents the ends of the tongues 1042a and 1042b opposite the screw 1046, from passing through the opening 1031 once they have been engaged in this opening. Thus, the rod 1042 is snapped into the support 102. The stroke of the piston 104, along the axis A100 and in a direction away from the printed circuit board relative to the support 102, is limited by the support hooks 1042d against the axial surface 1030. Thus, when all the batteries 262 are removed and the hatch 27 is open, the piston is not likely to stress the conductive cables when torn off, or even fall out of the housing L26.

On the other hand, the end 1042e of the rod 1042 opposite the tongues 1042a and 1042b is engaged in a socket 1044a formed by the sleeve 1044. This mounting of the parts 1042 and 1044 one inside the other, as well as the use of the screw 1046 ensures a rigid and lasting connection between the parts 1042 and 1044.

The sleeve 1044 comprises a peripheral skirt 1044a as well as lugs 1044b which end in plates 1044d for hooking and retaining the printed circuit board 106 on the piston 104. Hooks 1044e provided on the plates 1044d cooperate with the edge of the printed circuit board 106 to immobilize it on the piston 104. This allows the slide-in mounting of the printed circuit board 106 on the piston 104, in the direction of the arrow F4 in FIG. 3, perpendicular to the axis A100 along which the piston 104 slides. The printed circuit board 106 is then perpendicular to the axis A100.

When the play take-up mechanism 100 is mounted, the rod 1042 passes through the opening 1031 as explained above and the skirts 1032 and 1044b together define, around the rod 1042, a housing L120 for receiving the spring 120 in a configuration where the latter is supported, on the one hand, on the wall 1030 and, on the other hand, on an axial wall 1044f of the sleeve 1044, which is perpendicular to the axis A100. In this configuration, the spring 120 is interposed axially between the walls 1030 and 1044f and compressed, in the direction of the axis A100, so that it exerts on the piston 104 an axial force E120, that is to say parallel to the axis A100, directed towards the printed circuit board 106 which, since it is integral with the piston 100, is thus pushed towards the positive terminal 264 of the adjacent battery 262, whatever the position of this terminal positive along the axis A26, within a tolerance range corresponding to the stroke C104 of the piston between its two extreme positions, in normal operation. These positions are respectively shown in Figures 2 to 8 on the one hand, and 9 and 10 on the other hand. The C104 stroke is greater than 12 mm, preferably of the order of 15 mm.

In the extreme position, in FIGS. 1 to 8, the hooks 1042d are in abutment against the wall 1030. In the extreme position in FIGS. 9 and 10, the plates 1044d are arranged, along the axis A100, at an axial distance d100 equal to approximately 1 mm relative to the free edge of the skirt 1038. Thus, there is a possibility of overtravel, beyond the extreme position in normal operation shown in FIGS. 9 and 10, which allows, on the one hand, to limit the risks of shearing of a conductive cable accidentally leaving the housing L102 and, on the other hand, of accommodating an additional displacement resulting from improper handling on the part of a user, or from a shock.

The respective shapes of the support 102 and of the piston 104 are such that the support 102 guides the piston 104 in translation along the axis A100, in particular because the peripheral skirt 1044b penetrates into and is guided by the skirt 1032, and because the rod 1042 is guided in opening 1031.

As visible in FIG. 3, the support 102 is equipped with two notches 1023 and 1025 for the passage of the conducting wires.

In addition, two projections 1027 and 1029 are arranged on either side of the notches 1023 and 1025 and extend, from the support 102, in the direction of the printed circuit board 106. These projections 1027 and 1029 have the function allow the attachment and retention of a wire guide not shown in which circulate, in the direction of the hatch 27, a cable for taking up the potential of the negative terminal 266 of the battery 262 furthest from the catch-up mechanism of clearance 100, as well as an antenna cable, these cables not being shown.

The assembly of the mechanism 100 takes place by first manufacturing the piston 104, by mounting the parts 1042 and 1044 and their relative fixing by means of the screw 1046. Then the spring 120 is slid around the rod 1042, until 'coming to bear against the axial wall 1044f of the sleeve 1044. The tabs 1042a and 1042b and their respective hooks 1042d are dimensioned so that the spring 120 is then retained in position around the rod 1042 by the hooks 1042d. More specifically, the size and orientation of the hooks 1042d are chosen so that, in the unconstrained configuration of the tabs 1042a and 1042b, the maximum distance between these hooks is greater than the internal diameter of the spring 120. Under these conditions, the hooks 1042d form means for temporarily retaining the helical spring 120 on the rod 1042 during assembly of the play take-up mechanism 100, as long as the rod 1042 has not been introduced into the opening 1031, which takes place by to an elastic deformation of the tongues 1042a and 1042b, in a direction of closing of the slot 1042c. This elastic deformation is obtained by the simple passage of the hooks 1042d in the opening 1031, thanks to their generally triangular and convergent section opposite the sleeve 1044.

In view of the above, the backlash mechanism 100 makes it possible to effectively position the stud 110 in contact with the positive terminal 264 of the battery 262 closest to this mechanism 100, even though the manufacturing tolerances of the batteries 262 and of the casing 30 can be relatively large, which can induce variations in the positioning of this terminal 264 along the axis A26 with an amplitude of the order of 12 mm, or even more. As the stroke C104 is greater than or equal to this value, the backlash mechanism 100 is effective in all the configurations of use of the drive system 1.

In the second embodiment of the invention shown in Figure 11, elements similar to those of the first embodiment have the same references and operate in the same way. In what follows, we only describe what distinguishes this embodiment from the previous one.

Here, the batteries 262 of the power supply unit 26 are housed outside the casing 30 of the electromechanical actuator 3, while remaining in a housing L5 defined inside the winding tube 5, this housing being centered on an axis A5 which is a central axis of the winding tube 5, coincident with the axis of rotation X-X 'in the mounted configuration of the installation 200 and of the drive system 1 of this embodiment.

In practice, the batteries 262 are received in a housing 53 integrated into the winding tube 5, in the vicinity of the ring 44, which housing 53 is centered on the axis A5. The play take-up mechanism 100, which can be identical or analogous to that of the first embodiment, is mounted in the housing 53, within the winding shaft 5.

As a variant, the box 53 can be omitted, the batteries 262 are mounted directly in the housing L5 and the backlash mechanism 100 is mounted directly in the winding tube 5.

According to another variant, not shown, of the invention, the housing for receiving the batteries 262 from the power supply unit 26 can be provided outside the winding tube 5.

Whatever the embodiment, the longitudinal axis of a battery receiving housing is the axis of a stack of batteries located in this housing.

The play take-up device 100 is described above in the case of its implementation within a solar protection installation. It can also be used within a locking installation.

The embodiments and variants envisaged above can be combined with one another to generate new embodiments of the invention.

Claims (10)

1. -System (1) for driving a mobile screen (6) in a locking or sun protection installation, this system comprising - a tube (5) for winding the mobile screen, this tube being mobile in rotation about an axis of rotation (X-X ’), - a tubular electromechanical actuator (3) for driving the winding tube, this actuator being housed in the winding tube and - a housing (L26, L5) for receiving at least two batteries (262) intended for supplying an electric motor (33) of the tubular electromechanical actuator, characterized in that a mechanism (100) for take-up of axial clearance arranged in the receiving housing (L26, L5), comprises: - a support (102) mounted in the receiving housing (L26, L5), - a piston (104), sliding relative to the support along a sliding axis (A100) parallel to a longitudinal axis (A26, A5) of the receiving housing, being guided by the support, and which is equipped with a member (110) of electrical contact with a terminal (264) of an adjacent battery (262), - a helical spring (120) interposed axially, along the axis of sliding of the piston, between the support (102) and the piston (104) and which exerts on the piston an effort (E120) of elastic return towards the adjacent battery (262). 2, - System according to claim 1, characterized in that the piston supports a printed circuit board (106) which carries the electrical contact member (110) and an electrical connector (114) for connection of at least one cable driver. 3. - System according to claim 2, characterized in that each conductive cable connected to the electrical connector (114) is wound over at least 180 ° around the sliding axis (A100) of the piston (104). 4, - System according to claim 3, characterized in that the support is provided with a peripheral skirt (1038) defining a housing (L102) for receiving a portion of at least one conductive cable connected to the circuit board printed (106) and wrapped around the sliding axis (A100) of the piston (104). 5. - System according to one of claims 2 to 4, characterized in that the piston (104) comprises members (1044d, 1044e) for hooking the printed circuit board (106) in a configuration where this card is perpendicular to the sliding axis (A100) of the piston (104). 6. - System according to one of the preceding claims, characterized in that the support (102) comprises a relief (1026) blocking in rotation, around a longitudinal axis (A26, A5) of the receiving housing (L26, L5), inside this housing. 7. - System according to one of the preceding claims, characterized in that the piston (104) comprises a rod (1042) engaged in a through hole (1031) of the support (102) and in that the helical spring (120) is arranged around this rod, in axial abutment against, on the one hand, the support and, on the other hand, the piston. 8. -System according to claim 7, characterized in that the rod (1042) of the piston (104) is provided with reliefs (1042d) latching in the through hole (1031) of the support (102) and in that these reliefs form means for temporarily retaining the helical spring (120) on this rod, during assembly of the mechanism (100) for taking up play. 9. - System according to one of the preceding claims, characterized in that the support (102) and the piston (104) are each provided with a peripheral skirt (1032, 1044b) and in that the two skirts define together, radially outwards with respect to the longitudinal axis (A26), a housing (L120) for receiving the helical spring (120). 10. - Installation (200) for closing or sun protection comprising a screen (6) movable by winding on a winding tube (5) and a drive system (1) according to one of the preceding claims.