Field of application
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The present invention regards a roller blind.
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The present roller blind is intended to be employed in external settings for the covering of underlying surfaces from atmospheric agents and in particular from the sun and rain.
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Advantageously, the present roller blind is adapted to be employed for making pergolas or verandas, or to be applied on roofs of buildings for darkening skylights, both on horizontal and tilted surfaces.
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The roller blind, object of the present invention, therefore falls within the industrial field of production of sun blinds.
State of the art
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Known on the market or numerous solutions of sun blinds employed for creating a shading area, protected from the sun or rain.
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In particular, roller blinds are known which are arranged on pergolas or roofs and are generally provided with a box which houses a take-up roller at its interior, on which a flexible sheet is susceptible of being wound and unwound.
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The sheet of the blind usually has rectangular form and is provided with a rear edge fixed to the take-up roller and with a front edge fixed to a front bar aimed to stretch and maintain the sheet itself in position.
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The blind also comprises two lateral guides, parallel to and side-by-side each other, with which the respective ends of the front bar are slidably constrained.
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In operation, the take-up roller of the blind is actuatable to rotate in order to move the sheet between a collected position, in which the sheet is wound around the take-up roller, and an extended position, in which the sheet is unwound between the lateral guides of the blind. For such purpose, the blind comprises an electric motor mechanically connected to the take-up roller in order to actuate it to rotate so as to move the sheet between the extended position and the collected position.
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The lateral guides of the blind are placed horizontally (e.g. if they are mounted on the beams of a pergola) or tilted downward (e.g. if mounded on a tilted roof or on a veranda). Such arrangement ensures that, when the sheet must be unwound, the front bar cannot be lowered due to just the force of gravity. Consequently, in order to move the front bar and maintain the sheet taut, he blind comprises tensioning means which are able to force the front bar away from the take-up roller. For example, such tensioning means comprise gas springs placed in the lateral guides of the blind, connected to the ends of the front bar and loaded in a manner such to force the latter away from the take-up roller in order to force, consequently, the unwinding of the sheet.
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In this manner, when the motor of the blind is actuated in order to unwind the sheet, the gas springs push the front bar to slide along the lateral guides until the motor is stopped, maintaining the sheet taut.
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Several examples of blinds having tensioning means obtained with gas springs are described in the documents
EP 3851610 B1 and
DE 19807541 C1 .
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Such solution however has several drawbacks due to the arrangement of the gas springs in the lateral guides of the blind.
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Also known are roller blinds in which the tensioning means are obtained by means of a cable system applied to the front bar.
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More in detail, such system comprises two winding reels, each of which constrained to the corresponding end of the take-up roller and adapted to wind and unwind a corresponding traction cable placed within the corresponding lateral guide of the blind. Such traction cable is extended within the lateral guide up to a transmission pulley, placed at the front end of the corresponding lateral guide, and continues up to a terminal end thereof which is fixed to the corresponding end of the front bar.
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The traction cable is arranged in a manner such that, when the sheet is unwound from the take-up roller, this is wound around the winding reel, so as to drive the front bar away from the take-up roller. Vice versa, when the sheet is wound around the take-up roller, the traction cable is unwound from the winding reel, so as to allow the front bar to be pulled by the sheet towards the take-up roller.
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In order to obtain the aforesaid opposite movement of the traction cable with respect to the sheet, the tensioning system of the blind is provided with a transmission roller placed, in the respective lateral guide, in proximity to the respective winding reel and adapted to curve the extension of the traction cable such that the latter enters into the winding reel with sense opposite that with which the sheet enter into the take-up roller.
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In operation, since the sheet and the traction cable can have different thicknesses and form windings with different diameter during the unwinding and winding of the sheet, it is possible that the traction cable be wound with different speed with respect to that with which the sheet is unwound, and vice versa. This could ensure that the front bar is not moved with the same linear speed as the section of sheet unwound along the lateral guides, with consequent floppiness or excessive tensioning of the sheet.
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In order to resolve such drawback, the roller blinds comprise a compensation spring placed between the take-up roller and the winding reel, for example a torsional spring, which is adapted to be deformed in extension or contraction when the speeds of the sheet and of the traction cable are not synchronized.
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In addition, the compensation spring is preloaded in order to force the take-up roller in winding, so as to constantly maintain the sheet under tension.
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One example of this type of blinds is described in the document
GB 2535506 A .
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Nevertheless, even the latter solution of known type does not lack drawbacks.
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A first drawback is due to the fact that the compensation spring must be preloaded in order to allow the correct opening and closing of the sheet in all operating conditions of the latter and of the traction cable. For such purpose, during installation, before attaching the terminal end of the traction cable to the front bar, the traction cable is arranged in a manner such that, with the compensation spring at rest, the terminal end of the traction cable is separated from the front bar by a specific distance, for example 30 to 50 cm. In order to connect the terminal end to the front bar, the operator must pull the traction cable up to bringing it to the front bar, causing a deformation of the compensation spring with respect to the rest position, which determines the necessary preloading of the latter.
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Such operation normally requires the operator to execute a considerable force, since he/she must overcome the elastic return force of the compensation spring until he/she is able to couple the terminal end of the traction cable to the front bar. In addition, such operation must be executed when the blind is already mounted and hence the operator must operate on a ladder or on a scaffolding (or on a roof), rendering the operation particularly difficult and dangerous.
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A further drawback is due to the fact that it is necessary to determine, with high precision, the length of the traction cable as a function of the characteristics of the compensation spring (e.g. its dimensions and its elasticity constant), in a manner such that the operation of coupling the terminal end of the traction cable to the front bar determines the correct pretensioning of the compensation spring itself. In such condition, even slight tolerances in the measurement of the length of the traction cable can involve the incorrect winding or unwinding of the sheet.
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A further drawback is due to the fact that it is necessary to arrange the transmission roller at the winding reel of the tensioning system (so as to ensure the winding of the traction cable when the sheet is unwound, and vice versa), and such transmission roller determines a point of greater stress on traction cable, reducing the useful lifetime thereof.
Presentation of the invention
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In this situation, the problem underlying the present invention is therefore that of eliminating the abovementioned drawbacks of the solutions of known type, by providing a roller blind and a method for executing the preloading of elastic compensation means of said roller blind, which allow executing the pretensioning of the elastic compensation means in a simple, quick and safe manner for the operators.
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A further object of the present invention is to provide a roller blind, which is structurally simple and inexpensive to make, in particular not requiring stringent tolerances for the sizing of the traction cables.
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A further object of the present invention is to provide a roller blind, which is reliable in operation, in particular not requiring frequent maintenance operations for the substitution of parts subjected to wear (such as the traction cables).
Brief description of the drawings
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The technical characteristics of the present invention, according to the aforesaid objects, can be clearly seen in the contents of the below-reported claims and the advantages thereof will be more evident in the following detailed description, made with reference to the enclosed drawings, which represent several merely exemplifying and non-limiting embodiments of the invention, in which:
- figure 1 shows a top front perspective view of the roller blind, object of the present invention;
- figure 2 shows a schematic side view of the present blind, in accordance with a first embodiment of the invention, with several internal parts of the lateral guides and box of the blind itself illustrated in a simplified manner;
- figure 3 shows a top schematic view of the blind of figure 2, with several internal parts of the lateral guides and box of the blind itself represented in a simplified manner;
- figure 4 shows a detail of the present blind, partially in exploded view, comprising the actuation means and a transmission mechanism, in accordance with a first embodiment of the transmission mechanism;
- figure 5 shows a longitudinal section view of the (assembled) detail of figure 4;
- figure 6 shows a detail of figure 5, indicated in the square VI of figure 5 itself;
- figure 7 shows an exploded view of the transmission mechanism of the present blind;
- figure 8 shows an exploded perspective view of the transmission mechanism in accordance with a second embodiment of the transmission mechanism itself;
- figure 9 shows a block diagram that represents, in a simplified manner, the connections between different components of the blind according to the first embodiment of figure 2 and 3;
- figure 10 shows a top schematic view of the present blind, in accordance with a second embodiment of the blind itself.
Detailed description of a preferred embodiment
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With reference to the enclosed drawings, reference number 1 overall indicates a roller blind, object of the present invention.
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The present roller blind 1 is intended to be employed in external settings for the covering of underlying surfaces from atmospheric agents and in particular from the sun and rain.
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For example, the present roller blind 1 is adapted to be employed for making pergolas or verandas or to be applied on roofs of buildings for the darkening of skylights, both on horizontal and tilted surfaces (downward and possibly also slightly upward).
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With reference to figures 1-3, the roller blind 1 comprises a support frame 2, which, depending on the applications, can be mounted on the ground or on another support structure (as indicated in the examples described hereinbelow).
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The roller blind 1 also comprises a take-up roller 3 rotatably mounted on the support frame 2 around a first rotation axis X, preferably substantially horizontal.
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The take-up roller 3 is extended along the first rotation axis X between two opposite ends 4, which in particular are rotatably constrained to the support frame 2 of the roller blind 1. For example, the support frame 2 comprises two lateral brackets (not illustrated in the enclosed figures) on which the corresponding ends 4 of the take-up roller 3 are rotatably mounted thereon.
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Advantageously, with reference to figures 3-5, the take-up roller 3 comprises a central tubular body 5, with substantially cylindrical shape, and preferably two lateral caps 6 placed at the respective ends 4 of the take-up roller 3 to close the ends of the tubular body 5.
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Advantageously, the support frame 2 of the blind 1 comprises a box 7 in which the take-up roller 3 is housed.
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In particular, with reference to figures 1-3, the box is extended longitudinally, parallel to the first rotation axis X of the take-up roller 3, between two lateral heads 8, at which the respective ends 4 of the take-up roller 3 itself are placed and, advantageously, the respective lateral brackets to which such ends 4 are rotatably connected.
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The roller blind 1 also comprises a sheet 9, of flexible material, which is susceptible of being wound and unwound around the take-up roller 3.
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The sheet 9 can be intended for making a darkening screen for filtering the sunlight and for protecting from rain or snow. In particular, the sheet 9, as a function of its different applications, can be made of fabric of synthetic material (e.g. PVC) or natural material.
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Suitably, on a front side of the box 7, a longitudinal slit is defined, traversed by the sheet 9 in order to allow the movement of the latter.
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Preferably, the roller blind 1 also comprises two lateral guides 10 extended parallel to and side-by-side each other. Each lateral guide 10 is extended longitudinally according to a respective first extension direction Y substantially orthogonal to the first rotation axis X of the take-up roller 3, between a rear end 10°, positioned at the respective end 4 of the take-up roller 3, and an opposite front end 10". Between the lateral guides 10, the sheet 9 is susceptible of sliding following its winding and unwinding around the take-up roller 3.
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The sheet 9 has a preferably rectangular shape and is provided, in a manner per se known to the man skilled in the art, with a first edge fixed to the take-up roller 3 and with a second edge fixed to a front bar 11 slidably constrained to the lateral guides 10.
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The aforesaid front bar 11, which is fixed to the second edge of the sheet 9, is extended, along a second extension direction Z parallel to the first rotation axis X of the take-up roller 3, between two opposite lateral terminations 12, each of which slidably engaged with the corresponding lateral guide 10. Preferably, the front bar 11 is provided, at its lateral terminations, with slide wheels slidably engaged on the respective lateral guides 10.
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Advantageously, the take-up roller 3, the lateral guides 10 and the front bar 11 lie on a lying plane. In particular, such lying plane is adapted to be placed, depending on the applications, horizontally, or tilted downward (i.e. descending from the rear end 10' to the front ends 10" of the lateral guides 10) even with relatively high tilts (even greater than 45°), or even tilted upward (generally with slight tilts, less than 5°), such lying plane possibly also able to be vertical.
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In accordance with a particular embodiment of the present blind 1, this is adapted to attain a pergola. In particular, in accordance with such embodiment, the support frame 2 comprises multiple columns, which support at least one pair of longitudinal members which are advantageously constituted by the lateral guides 10 of the blind 1. For example, the pergola can be self-supporting (in particular provided with at least four angular columns) or leaned against the wall (e.g. with two columns placed at the front ends 10" of the lateral guides 10 and with the box 7 fixed to a wall or to columns of a further structure).
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In accordance with a different embodiment, the present blind 1 is intended to be mounted on a separate and/or pre-existing support structure, such as on the roof of a house (e.g. at a skylight) or on the upper side of pergolas or verandas. In such case, for example, the support frame 2 comprises suitable support feet by means of which the lateral guides 10 and/or the box 7 of the blind 1 are fixed to the underlying support structure.
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The present blind 1 also comprises actuation means 13, which are mechanically connected to the take-up roller 3 in order to make it rotate around its first rotation axis X, in a first rotation sense V1 in order to wind the sheet 9 around the take-up roller 3, and in an opposite second sense V2 in order to unwind the sheet 9 from the take-up roller 3 itself.
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Advantageously, with reference to figure 2, the first rotation sense V1 (in order to wind the sheet 9) is counter-clockwise and the second rotation sense V2 (in order to unwind the sheet 9) is clockwise.
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Preferably, the actuation means 13 are placed at one of the ends 4 of the take-up roller 3 and are advantageously fixed to the support frame 2, for example at one of the support brackets of the latter.
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In particular, the actuation means 13 act as rotatable hinging element of the corresponding end 4 of the take-up roller 3 on the support frame 2. Preferably, the other end 4 of the take-up roller 3 is mounted on the support frame 2 by means of an idle pin.
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Advantageously, the actuation means 13 are actuatable for moving the sheet 9 between a collected position, in which the sheet 9 is wound around the take-up roller 3, and an extended position, in which the sheet 9 is unwound from the take-up roller 3, being extended along the lateral guides 10, to cover the underlying surface.
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Advantageously, as is visible in the example of figures 4-6, the actuation means 13 are of motorized type, comprising in particular an electric motor 14, in order to move the take-up roller 3 in an automated or semi-automated manner. Preferably, the electric motor 14 comprises a support body 15 (preferably tubular) fixed to the support frame 2 (e.g. on the respective support bracket) and an output shaft 16 mechanically connected to the take-up roller 3 in order to rotate it. Suitably, the respective end 4 of the take-up roller 3 (and in particular the lateral cap 6) is rotatably supported by the support body 15 of the electric motor 14.
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In accordance with a different embodiment not illustrated in the enclosed figures, the actuation means 13 are of manual type (comprising in particular a hoist provided with a control rod engaged through a connection articulation to the respective end 4 of the take-up roller 3).
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The blind 1 is arranged in order to actuate the front bar 11 to slide along the lateral guides 10, in particular to move the front bar 11 towards the front ends 10" of the lateral guides 10 when the sheet 9 is unwound from the take-up roller 3 (during the normal operation of the blind 1).
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Indeed, on such matter, since the present blind 1 is often intended to be installed with the lying plane non-vertical (horizontal or tilted), the action of the force of gravity on the front bar 11 is normally not sufficient for advancing the latter when the sheet 9 is unwound.
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With reference to figures 2 and 3, the blind 1 comprises at least one winding reel 17, which is mechanically connected to the take-up roller 3 and, preferably, is placed at the respective end 4 of the latter.
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Such winding reel 17 is rotatable around a second rotation axis W, preferably parallel to the first rotation axis X of the take-up roller and in particular aligned with the first rotation axis X itself.
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The blind 1 also comprises at least one traction cable 18, which is windable around the winding reel 17 and is mechanically connected to the front bar 11.
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More in detail, the traction cable 18 (which is susceptible of being wound around the winding reel 17) is extended between a first end, which is constrained to the winding reel 17, and a second end, which is constrained to the corresponding lateral termination 12 of the front bar 11.
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The winding reel 17 is actuatable to rotate in a third rotation sense V3 in order to actuate the traction cable 18 to pull the front bar 11 towards the front ends 10" of the lateral guides 10, and in an opposite fourth rotation sense V4 in order to allow the front bar 11 to slide towards the rear ends 10' of the lateral guides 10.
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In particular, as discussed in detail hereinbelow, in this manner, when the sheet 9 is unwound from the take-up roller 3, the front bar 11 can be driven towards the front ends 10" of the lateral guides 10, allowing the correct extension of the sheet 9 (by actuating the winding reel 17 to rotate in the aforesaid third rotation sense V3). When, the sheet 9 is wound around the take-up roller 3, the front bar 11 can be left free to slide, such that it can be pulled by the sheet 9 towards the rear ends 10' of the lateral guides 10 (by actuating the winding reel 17 to rotate in the aforesaid fourth rotation sense V4).
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Advantageously, in accordance with the embodiment illustrated in figures 2 and 3, the blind 1 comprises two winding reels 17, preferably placed at the respective ends 4 of the take-up roller 3, and two respective traction cables 18, windable around the respective winding reels 17 and constrained, in particular at their second ends, to the front bar 11.
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Preferably, the traction cable 18 can have circular or flattened section, for example able to comprise a track, a belt, a rope, a cord, etc., of suitable material, as a function of the specific application.
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Preferably, the traction cable 18 is extended, for the section unwound from the winding reel 17, along the respective lateral guide 10, in particular within the latter.
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In accordance with the embodiment illustrated in figures 2 and 3, the traction cable 18 is extended from the winding reel 17 substantially up to the front end 10" of the lateral guide 10, and at such front end 10" a transmission pulley 19 is mounted, around which the traction cable 18 makes a 180° bend (towards the winding reel 17) up to its second end constrained to the lateral termination 12 of the front bar 11.
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With reference to a first embodiment illustrated in figures 2 and 3, the second end of the traction cable 18 is fixed to the respective lateral termination 12 of the front bar 11, for example being provided with a coupling eyelet coupled to a latch fixed to the lateral termination 12.
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With reference to a second embodiment illustrated in figure 10, the traction cable 18 enters with its second end in the front bar 11 at the respective lateral termination 12, by making an elbow bend around a transmission reel 20 mounted on such lateral termination 12. In particular, the second end of the traction cable 18 is placed within the front bar 11 and is constrained to the latter by means of elastic compensation means 21 (discussed in detail hereinbelow).
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Advantageously, the traction cable 18 is wound on the winding reel 17 with sense such that, with reference to figure 2, the third rotation sense V3 (for pulling the front bar 11 towards the front ends 10" of the lateral guides 10) is counter-clockwise and the fourth rotation sense V4 (for allowing the front bar 11 to slide towards the rear ends 10' of the lateral guides 10) is clockwise.
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Preferably, the third rotation sense V3 of the winding reel 17 is opposite the second rotation sense V2 of the take-up roller 3 and the fourth rotation sense V4 of the winding reel 17 is opposite the first rotation sense V1 of the take-up roller 3.
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The blind 1 also comprises elastic compensation means 21, elastically deformable, which in particular are arranged for ensuring the correct movement and tensioning of the sheet 9, as discussed hereinbelow.
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The aforesaid compensation means 21 are arranged in order to be elastically deformed to compensate for different speeds between the sheet 9 and the traction cable 18 under movement, i.e. when sheet 9 and traction cable 18 are in movement in order to allow the unwinding or winding of the sheet 9 itself.
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The elastic compensation means 21 are also elastically preloaded in order to maintain the sheet 9 under tension, in particular when the latter is unwound from the take-up roller 3.
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More in detail, the elastic compensation means 21 are preloaded with a specific elastic potential energy that induces the latter to exert an elastic force which is transmitted to the sheet 9 in order to maintain it taut.
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Advantageously, the elastic compensation means 21 are operatively connected to the sheet 9 (in particular by means of the take-up roller 3 and/or the front bar 11) and/or to the traction cable 18 (in particular by means of the winding reel 19 and/or the front bar 11).
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Advantageously, with reference to the first embodiment of figures 2-3, the elastic compensation means 21 are operatively connected to the take-up roller 3 and are arranged for exerting on the latter an elastic force (given at least by the aforesaid elastic potential energy) that forces the take-up roller 3 to rotate in the first rotation sense V1 in order to pull the sheet 9 in winding.
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In particular, the elastic compensation means 21 are indirectly connected to the take-up roller 3, in a manner such that the aforesaid elastic force is transmitted to the take-up roller 3 through other components of the blind 1, as will for example be discussed hereinbelow. Otherwise, the elastic compensation means 21 are directly connected to the take-up roller 3.
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In accordance with the second embodiment illustrated in figure 10, the elastic compensation means 21 are placed in the front bar 11 to connect the second ends of the two traction cables 18. In particular, the elastic compensation means 21 are loaded for exerting an elastic force that pulls the two second ends close together, forcing the traction cables 18 (by means of the abovementioned transmissions) to force the front bar 11 away from the take-up roller 3, in this manner maintaining the sheet 9 under tension.
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As indicated above, the elastic compensation means 21 are elastically deformable in order to compensate for speed differences between the sheet 9 and the traction cable 18, and which are generally due to differences of diameter between the take-up roller 3 and the winding reel 17 and/or differences of thickness between the sheet 9 and the traction cable 18. For example, if during the unwinding of the sheet 9 the traction cable 18, even only in a few moments, is moved with greater speed than the sheet 9 (hence tending to pull also the front bar 11 with greater speed than the latter), the elastic compensation means 21 elastically yield, in substance by lengthening the path taken by the traction cable 18, synchronizing the speed with the movement with the sheet 9. Vice versa, if during the unwinding of the sheet 9 the traction cable 18, even only in a few moments, is moved with a lower speed than the sheet 9 (hence tending to pull also the front bar 11 with lower speed than the latter, for example determining a floppiness of the sheet 9), the elastic compensation means 21, in particular due to their preloading, exert an elastic force that still maintains the sheet 9 under tension.
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In accordance with the idea underlying the present invention, the present blind 1 comprises at least one transmission mechanism 22 mechanically connected to the winding reel 17, and provided at least with two alternately settable operative configurations, in order to modify the mutual movement between winding reel 17 and take-up roller 3, as discussed in detail hereinbelow.
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Advantageously, the actuation means 13, the take-up roller 3, the sheet 9, the front bar 11, the winding reel 17, the traction cable 18, the transmission mechanism 22 and the elastic compensation means 21 are interconnected (in particular as described above) so as to form a kinematic succession of components which allows transmitting the motion (initially generated by the actuation means 13) to the sheet 9 and to the front bar 11.
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A block diagram which represents a possible example of the interconnections between the aforesaid components is represented in figure 9.
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In accordance with such example, the actuation means 13 are mechanically connected to the take-up roller 3 in order to actuate it in rotation such to wind or unwind the sheet 9 which, when it is wound, moves the front bar 11. In addition, the rotation motion of the take-up roller 3 is transmitted to the winding reel 17, for example by means of the transmission mechanism 22 and/or the elastic compensation means 21. The rotation of the winding reel 17 determines the movement of the traction cable 18 and (when it is wound) of the front bar 11.
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Advantageously, the blind 1 comprises two transmission mechanisms 22, each of which associated with the corresponding winding reel 17, for example as represented in the examples of figures 3 and 9.
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Advantageously, the transmission mechanism 22 is placed as a connection between the take-up roller 3 and the winding reel 17.
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In this manner, in particular, with reference to the above-indicated example, the transmission mechanism 22 receives the rotary motion from the take-up roller 3 and transmits it (possibly transforming it) to the winding reel 17. Of course a different configuration of the actuation means 13 is also possible where the latter are connected to the winding reel 17 and the motion is transmitted by the latter to the take-up roller 3 by means of the transmission mechanism 22.
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Also other configurations are possible, in which for example the output of the actuation means 13 is divided in two (for example by means of a transmission box), of which a first output is connected to the winding reel 17, in particular by means of the transmission mechanism 22, and the other output is connected to the take-up roller 3.
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Advantageously, in accordance with the examples of figures 3-5 and 9, the elastic compensation means 21 are interposed between the take-up roller 3 and the winding reel 17, and in particular between the take-up roller 3 and the transmission mechanism 22.
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In this manner, in particular, the elastic compensation means 21 are also adapted to transmit the motion from the take-up roller 3 to the winding reel 17 (preferably also by means of the transmission mechanism 22), and vice versa.
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In accordance with the second embodiment of figure 10, the elastic compensation means 21 are placed in the front bar 11, to connect between the second ends of the traction cables 18.
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In accordance with further different embodiments, the elastic compensation means 21 can be placed at any other point of the aforesaid kinematic succession, for example between the transmission mechanism 22 and the winding reel 17, or between the traction cable 18 and the front bar 11, or between two sections of the traction cable 18, etc.
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In accordance with the particular embodiment illustrated in figures 4 and 5, the output shaft 16 of the electric motor 14 of the actuation means 13 is rigidly connected to the take-up roller 3, in particular by means of a connection rod 23 having one end fixed to the output shaft 16 of the electric motor 14 and the other end carrying, fixed thereto, a coupling head 24 inserted in the tubular body 5 of the take-up roller 3 and fixed thereto. The elastic compensation means 21 are placed to connect between the aforesaid coupling head 24 and a rotatable bearing 25 idly mounted on the connection rod 23 and rigidly fixed to a transmission tube 26 in turn connected to the transmission mechanism 22. In this manner, in particular, the motion is transferred from the output shaft 16 of the electric motor 14 to the take-up roller 3 (by means of the connection rod 23 and the coupling head 24), from the take-up roller 3 to the elastic compensation means 21, which in turn transmit the motion to the transmission mechanism 22, in particular by means of the rotatable bearing 25 and the transmission tube 26.
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Advantageously, at the end 4 of the take-up roller 3 where the actuation means 13 are not placed, the transmission mechanism 22 is connected to the take-up roller 3 by means of the elastic compensation means 21 by means of a configuration given by coupling head - connection rod - rotatable bearing analogous to that described above.
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Advantageously, the elastic compensation means 21 comprise at least one spring (for example of mechanical type or a gas spring).
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In accordance with the embodiment illustrated in figures 4 and 5, the elastic compensation means 21 comprise a torsion spring 27 having one end fixed to the take-up roller 3 (in particular by means of the coupling head 24) and the other end fixed to the rotatable bearing 25.
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In accordance with the second embodiment illustrated in figure 10, the elastic compensation means comprise an internal spring 28, traction or compression (mechanical or gas), placed within the front bar 11 and placed to connect the two second ends of the two traction cables 18.
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As reported above, the transmission mechanism 22 of the blind 1 is provided with two operative configurations, including a first operative configuration (for executing the pretensioning of the elastic compensation means 21) and a second operative configuration (for allowing the winding and the unwinding of the sheet 9 during the normal operation of the blind 1).
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In particular, the first operative configuration is set during installation of the blind 1, or during maintenance (e.g. for substituting a component such as the traction cable 18), while the second configuration is set during the normal use of the blind in order to allow the final user to control the opening and closing of the blind 1 itself.
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More in detail, in the first operative configuration, the transmission mechanism 22 is arranged in a manner such that, when the take-up roller 3 is actuated for rotating in the first rotation sense V1 for winding the sheet 9, the winding reel 17 is actuated for rotating in the third rotation sense V3 so as to pull the front bar 11 towards the front ends 10" of the lateral guides 10 and hence to unwind the sheet 9. This determines an elastic deformation of the elastic compensation means 21 in order to preload the latter with a predetermined elastic potential energy (which allows maintaining the sheet 9 under tension).
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More in detail, in this condition, the sheet 9 pulls the front bar 11 towards the rear ends 10' of the lateral guides 10 and the winding reel 17, by means of the traction cable 18, pulls the front bar 11 towards the front ends 10" of the lateral guides 10 (i.e. in the opposite sense).
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In such condition, therefore, on the front bar 11, two forces with opposite direction are exerted, i.e. a first force exerted by the sheet 9 that tends to pull the front bar 11 towards the rear ends 10' of the lateral guides 10, and a second force exerted by the traction cable 18 that tends to pull the front bar 11 towards the front ends 10" of the lateral guides 10.
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In this condition, most of the energy of the actuation means 13, that generates the aforesaid force on the front bar 11, is not transformed into kinetic energy, since the opposite forces applied to the front bar 11 prevent or in any case strongly limit the movement thereof (and consequently also the movement of the other components: sheet 9, take-up roller 3, traction cable 18, winding reel 18). In this condition, the energy is accumulated in the elastic compensation means 21 in the form of potential elastic energy.
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Indeed, the force (or the torque) applied by the actuation means 13 to the kinematic succession which transmits the motion to the sheet 9 and to the front bar 11, not generating work due to the substantial immobility of the latter, cause the elastic deformation of the elastic compensation means 21 and hence an accumulation of elastic potential energy.
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In particular, with reference to the example of figures 4 and 5, the locking (or limited movement) of the front bar 11 determines a consequent locking of the winding reel 17 which keeps stopped the second end of the torsion spring 27 of the elastic compensation means 21, such that the motion transmitted by the take-up roller 3 to the first end of the torsion spring 27 determines a deformation of the latter with consequent accumulation of elastic potential energy. With reference to the example of figure 10, the locking (or the limited movement) of the front bar 11 ensures that the traction cables 18 extend the internal spring 28, determining the loading thereof.
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In this manner, the configuration of the transmission mechanism 22 according to the invention allows, in particular during installation or maintenance of the blind 1, easily preloading the elastic compensation means 21 by using the energy of the actuation means 13 of the blind 1 itself, in particular without the need for the operators to have to sustain high stresses in difficult or dangerous positions.
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In addition, the quantity of elastic potential energy of the elastic compensation means 21 (i.e. their preloading) can be determined by simply setting the duration of actuation of the actuation means 13 (in particular of the electric motor 14) without having to calculate precise lengths of the traction cables 18.
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In the second operative configuration, the transmission mechanism 22 is arranged in a manner such that, when the take-up roller 3 is actuated in the second rotation sense V2 in order to unwind the sheet 9, the winding reel 17 is actuated in the third rotation sense V3 in order to pull the front bar 11 towards the front ends 10" of the lateral guides 10, and, when the take-up roller 3 is actuated to rotate in the first rotation sense V1 in order to wind the sheet 9, the winding reel 17 is actuated in the fourth rotation sense V4 in order to allow the front bar 11 (pulled by the sheet 9) to slide towards the rear ends 10' of the lateral guides 10.
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This second configuration is set during the normal operation of the blind 1 and allows, when the sheet 9 is unwound, moving the front bar 11 (following the action of the traction cable 18) and, when the sheet 9 is wound, leaving the front bar 11 free to slide along the lateral guides 10 such that it can be driven by the sheet 9 towards the take-up roller 3.
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Advantageously, in the first operative configuration, the transmission mechanism 22 is configured for providing, at the output, a rotation motion having sense opposite that which it provides at the output in the second operative configuration. In this manner, in particular, when the take-up roller 3 is actuated in the first winding sense V1, the transmission mechanism 22, in the first operative configuration, actuates the winding reel in the third rotation sense V3, and in the second operative configuration actuates the winding reel 17 in the opposite fourth rotation sense V4.
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In this manner it is possible to set the winding sense of the traction cable 18 with respect to that of the sheet 9 without having to employ transmission rollers for the traction cable 18 which could promote the wear thereof.
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Advantageously, the transmission mechanism 22 comprises an epicyclic gearing 29, as illustrated for example in the embodiments of figures 6, 7 and 8.
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More in detail, the epicyclic gearing 29 comprising a first sun gear 30, which is rotatable around a first axis A1 and is actuatable to rotate around such first axis A1 following the action of the actuation means 13. For example, the first sun gear 30 is actuatable by the motion that is transmitted thereto by the take-up roller 3, optionally through the elastic compensation means 21.
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In accordance with the example of the enclosed figures, the first sun gear 30 is fixed to the transmission tube 26 in turn connected (by means of the rotatable bearing 25, the elastic compensation means 21 and the coupling head 24) to the take-up roller 3.
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The epicyclic gearing 29 also comprises a second sun gear 31 rotatable around a second axis A2, preferably parallel to the first axis A1 of the first sun gear 30, and mechanically connected to the winding reel 17 in order to rotate it when the first sun gear 30 is actuated. For example, the second sun gear 31 is rigidly fixed to the winding reel 17.
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The epicyclic gearing 29 also comprises a carrier 32 rotatable around a third axis A3, preferably parallel to the first axis A1 of the first sun gear 30, and carrying, mounted thereon, multiple planet gears 33, which are rotatable around their fourth axes A4 and are engaged with the first sun gear 30 and with the second sun gear 31 in order to allow the transmission of the motion between the latter (at least in the second operative configuration).
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In particular, the first sun gear 30 comprises a first toothing 34 and the second sun gear 31 comprises a second toothing 35, and such toothing are engaged by the planet gears 33 of the carrier 32.
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In accordance with the embodiment illustrated in the enclosed figures, the first sun gear 30 is a (central) sun pinion and the second sun gear 31 is a toothed crown. In particular, the sun pinion is fixed to the transmission tube 26 and the toothed crown carries the winding reel 17 fixed thereto.
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In accordance with a different embodiment, the first sun gear 30 is a toothed crown and the second sun gear 31 is a sun pinion.
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Advantageously, the carrier 32 has substantially annular shape and carries, mounted thereon, the planet gears 33 placed around its third axis A3, preferably equidistant one from the next.
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Preferably, the first axis A1 of the first sun gear 30 is parallel to the second axis A2 of the second sun gear 31 and to the third axis A3 of the carrier 32 and, more preferably, is aligned with such second axis A2 and third axis A3.
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Advantageously, the first axis A1 of the first sun gear 30 of the epicyclic gearing 29 is parallel to the first rotation axis X of the take-up roller 3 and preferably is aligned with the first rotation axis X itself.
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In particular, the epicyclic gearing 29 is placed at the respective end 4 of the take-up roller 3.
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Suitably, the first sun gear 30 is provided with a central hole within which the electric motor 14 is placed in a through manner, so as to be able to connect its output shaft 16 to the take-up roller 3 (in particular as described above).
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Advantageously, the transmission ratio of the epicyclic gearing 29 is substantially equal to 1, in particular with a deviation of ±0.05.
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Such transmission ratio avoids generating strong angular speed differences between the take-up roller 3 and the winding reel 17, and therefore maintaining limited the linear speed differences between the sheet 9 and the traction cable 18.
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Preferably, when the transmission mechanism 22 is in the first operative configuration (in order to preload the elastic compensation means 21), the carrier 32 of the epicyclic gearing 29 is locked to the first sun gear 30 or to the second sun gear 31 (or to both), preferably by means of first fixing means 36 comprising for example first screw means.
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In accordance with the example of figures 6 and 7, in the first operative configuration the carrier 32 is fixed to the second sun gear 31, for example by means of at least one first screw of the aforesaid first fixing means 36.
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In the first operative configuration, therefore, the carrier 32 is integral with the first and the second sun gear 30, 31, hence rotating integral with the latter. In particular, when the carrier 32 is fixed to one of the sun gears 30, 31, it is maintained integral with the other sun gear 31, 30 by the planet gears 33 which, unable to rotate, rigidly connect the first toothing 34 of the first sun gear 30 to the second toothing 35 of the second sun gear 31.
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In the first configuration, the carrier 32 is actuatable by the first sun gear 30 in order to rotate the second sun gear 31 with the same rotation sense as the first sun gear 30 (in particular integral with the latter), such that the epicyclic gearing 29 generates at the output a rotary motion in the same sense (and in particular kinematically equal) as that which it receives at the input.
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In the second operative configuration, the carrier 32 is locked to the support frame 2 of the blind 1, preferably by means of second fixing means 37 comprising for example second screw means. Advantageously, the support frame 2 comprises a support ring 38 (with which the support body 15 of the electric motor 14 is preferably fixed), for example rigidly fixed to the corresponding lateral bracket of the support frame 2. Such support ring 38 is placed adjacent to the carrier 32 according to the direction of the third axis A3 of the latter. Preferably, in the second operative configuration, the carrier 32 is fixed to the support ring 38 by means of at least one second screw of the second fixing means 37.
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In the second operative configuration, the carrier 32 is unlocked both from the first sun gear 30 and from the second sun gear 31, in the sense that it is not rigidly constrained to none of these two and is engaged to them only through the planet gears 33 engaged with the first and second toothing 34, 35 respectively of the first and the second sun gear 30, 31. In particular, in the second operative configuration, the first fixing means 36 are removed.
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In operation, in the second operative configuration, the planet gears 33 of the epicyclic gearing 29 are actuatable to rotate by the first sun gear 30 in order to rotate the second sun gear 31 with rotation sense opposite to that of the first sun gear 30.
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In this manner, in particular, the epicyclic gearing 29 generates at the output a reverse rotary motion with respect to that which it receives at the input.
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Of course, in the first operative configuration of the transmission mechanism 22, the second fixing means 37 are not applied to the epicyclic gearing 29, such that the carrier 32 is rotatably released from the support frame 2. In figures 5 and 6, first and the second fixing means 36, 37 are represented, simultaneously applied to the epicyclic gearing 29 for the sake of description efficiency, such first and second fixing means 36, 37 being applied alternately according to the the abovementioned first and second operative configuration.
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Advantageously, with reference to a first embodiment of the transmission mechanism 22 illustrated in figures 4 to 7, the epicyclic gearing 29 is a bevel gearing (in which the axes A1, A2, A3, A4 are not all parallel to each other).
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In particular, according to such first embodiment, the first and the second sun gear 30, 31 and the planet gears 33 are bevel gears.
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Advantageously, the fourth axes A4 of the planet gears 33 are placed in radial direction with respect to the first axis A1 of the first sun gear 30.
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More in detail, the first sun gear 30 is provided with a first engagement surface, which is placed on a plane substantially transverse to the first axis A1 of the first sun gear 30 itself, and on which the first toothing 34 of the latter is made.
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The second sun gear 31 is provided with a second engagement surface, which is placed on a plane substantially transverse to the second axis A2 of the second sun gear 31, and on which the second toothing 35 of the latter is made.
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The second engagement surface of the second sun gear 31 faces the first engagement surface of the first sun gear 30, with the planet gears 33 interposed between the first and the second engagement surface and engaged with the first and second toothing 34, 35.
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The aforesaid spherical configuration of the epicyclic gearing 29 allows maintaining the dimensions of the latter compact (in particular its width along the first axis A1), being able to simultaneously maintain a transmission ratio close to 1.
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In accordance with a second embodiment of the transmission mechanism 22, illustrated for example in figure 8, the epicyclic gearing 29 is a flat gearing (with all the axes A1, A2, A3, A4 parallel to each other). For example, the first sun gear 30 is a pinion with external toothing and the second sun gear is a gear with internal toothing placed around the first sun gear 30, with the planet gears 33 placed between the first and the second sun gear 30, 31.
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In accordance with further different embodiments not illustrated in the enclosed figures, the transmission mechanism 22 can be a non-epicyclic, and in general a kinematic chain formed by gears which allow at least two connections for setting the aforesaid first and second operative configuration.
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Also forming the object of the present invention is a method for executing the pretensioning of the elastic compensation means 21 of the present roller blind 1, regarding which the same reference numbers will be maintained for the sake of description simplicity.
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Such method is executed for example during the operations of installation of the blind 1, or during maintenance operations, for example for substituting specific components of the blind 1 such as the traction cable 18 or the elastic compensation means 21.
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The aforesaid method comprises the operative steps described hereinbelow.
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The transmission mechanism 22 is placed in the first operative configuration.
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Then, the actuation means 13 are actuated, in particular the electric motor 14 of the latter. Such actuation is for example enabled by an operator.
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The actuation means 13 determine the actuation of the take-up roller 3 in the first rotation sense V1 in order to wind the sheet 9 on the take-up roller 3 itself.
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In addition, the actuation means 13 determine the actuation of the transmission mechanism 22 which, being in the first operative configuration, rotate the winding reel 17 in the third rotation sense V3 in order to pull the front bar 11 towards the front ends 10" of the lateral guides 10 so as to unwind the sheet 9 from the take-up roller 3, so as to determine an elastic deformation of the elastic compensation means 21 in order to preload them.
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As mentioned above, in the aforesaid condition, two forces are exerted with opposite direction on the front bar 11, such that most of the energy of the actuation means is not transformed into kinetic energy, since the opposite forces applied to the front bar 11 prevent or in any case strongly limit the movement thereof. In this condition, the energy is accumulated in the elastic compensation means 21 in the form of potential elastic energy, since the force (or the torque) applied by the actuation means 13 determines an elastic deformation of the elastic compensation means 21 themselves.
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Advantageously, the actuation means 13 (and in particular the electric motor 14) are maintained active until the elastic compensation means 21 reach the desired preload (i.e. they accumulate the desired elastic potential energy).
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Subsequently, the transmission mechanism 22 is placed in the second operative configuration, so as to enable the normal operation of the blind 1 for the unwinding and winding of the sheet 9 (as already discussed above).
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Advantageously, the transmission mechanism 22 is placed in the first operative configuration by locking the carrier 32 of the epicyclic gearing 29 to at least one of the (first 30 and second 31) sun gears (preferably by means of the first fixing means 36). In this manner, when the actuation means 13 are actuated, the first sun gear 30 is actuated to rotate in order to rotate, by means of the carrier 32, the second sun gear 31 with the same rotation sense as the first sun gear 30. In particular, the second sun gear 31 and the carrier 32 rotate integral with the first sun gear 30.
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When the elastic compensation means 21 have been loaded with the desired elastic potential energy, in order to place the transmission mechanism 22 in the second operative configuration, the carrier 32 is locked to the support frame 2 (preferably by means of the second fixing means 37) and, subsequently, the carrier 32 is unlocked from the sun gears 30, 31 (preferably by removing the first fixing means 36), so as to be constrained to the first sun gear 30 and to the second sun gear 31 only through the planet gears 33.
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In this manner, by actuating the first sun gear 30, the second sun gear 31 is actuated with rotation sense opposite that of the first sun gear 30, as discussed in detail above.
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The invention thus conceived therefore attains the pre-established objects.