Ceiling fan with retractable blades and improved airflow

Abstract

The present invention relates to a ceiling fan (1) comprising a central body (11), a motor system, and a plurality of blades (12) configured to move between a first position and a second position, said blades (12) each extending between a first proximal end (121) of said axis of revolution (Z) and a second distal end (122) of said axis of revolution (Z) in said second position. The fan (1) includes a support (13) extending from said body (11), each of said blades (12) being assembled with said body (11) via said support (13) along an intermediate portion (123) so as to form a pivot (131), such that said movement from said first position to said second position corresponds to a movement of said first end (121) towards said axis of revolution (Z) and a movement of said second end (122) away from said axis of revolution (Z). Figure for the summary: Figure 4

Description

Title of the invention: Ceiling fan with retractable blades and improved airflow. Technical field

[0001] The present invention relates to the field of ceiling fans with retractable blades.

[0002] The present invention relates more particularly to an improved design ceiling fan device, exhibiting an airflow greater than conventional retractable blade ceiling fans.

[0003] The present invention will thus find many advantageous applications in the fields of furniture and interior design. Previous art

[0004] A ceiling fan is a fan designed to be fixed to the ceiling of a room. Such a fan consists of a central body and a set of blades extending from the central body, the blades being driven in rotation to provide ventilation in the interior space of the room. The central body may advantageously be equipped with lighting, so as to combine the functions of a light fixture and a fan.

[0005] It is also known to design ceiling fans with retractable blades. The fan blades are then configured, by various means, to extend to form a fan when they are set in rotation, and to retract when the fan is stopped. The retraction of the blades, generally onto the fan body, results in a more compact shape when not in use, which facilitates transport and installation, and can offer aesthetic advantages by presenting a shape distinct from a fan, particularly the shape of a light fixture.

[0006] The Applicant submits, however, that retractable blade fans have a significantly reduced airflow compared to a conventional fixed-blade ceiling fan. The Applicant thus estimates a flow loss of approximately 40% between a conventional fixed-blade ceiling fan and a retractable blade fan.

[0007] The Applicant therefore submits that there is currently no satisfactory alternative solution for a fan with retractable blades providing a suitable airflow. Summary of the invention

[0008] The present invention aims to improve the current situation described above.

[0009] The present invention aims more particularly to remedy the above disadvantages by proposing a ceiling fan with retractable blades whose structure allows a better airflow compared to existing solutions.

[0010] To this end, the object of the present invention relates in a first aspect to a ceiling fan comprising a central body defining an axis of revolution of the fan, a plurality of blades assembled to the body and a motorization system configured to drive the blades in rotation around the axis of revolution, the blades being configured to pass between a first position, called folded, corresponding to a stop of the fan, and a second position, called deployed, corresponding to a rotation of the fan, the blades each extending between a first proximal end of the axis of revolution and a second distal end of the axis of revolution in the second position.

[0011] It is understood here that the fan according to the present invention has characteristics of a retractable blade ceiling fan as known to those skilled in the art. The fan can thus comprise various variants known to those skilled in the art, particularly with regard to the number of blades, the size of the blades, the presence or absence of central lighting associated with the body, the angle of rotation associated with the blade deployment, or the specific shape of the blades. In particular, the number and size of the blades allow the ventilation rate and the diameter of the fan in the deployed position to be adjusted. The motor system can also be located in the central body, above or below the blades.

[0012] Advantageously, the fan includes a support extending from the body and driven by the motorization system, each of the blades being assembled with the body via the support according to an intermediate portion of the blade, the intermediate portion being mounted in rotation relative to the support so as to form a pivot around which the blade pivots to pass between the first position and the second position, said pivot being away from the axis of revolution, so that the passage from the first position to the second position corresponds to a bringing of the first end towards the axis of revolution and a moving away of the second end from the axis of revolution.

[0013] According to one embodiment, the support comprises a plurality of arms extending from the body away from the axis of revolution, each pivot being arranged between an arm, preferably at its distal end, and the intermediate portion of a blade. According to other variants, the support is in the form of a disk or a ring whose axis of revolution corresponds to that of the body, the pivots between the intermediate portions of blades and the disk being arranged at the periphery of the disk or on the ring, the blades deploying below or above the disk or ring. the ring. According to yet another variant, the body itself forms the support and is driven in rotation by the motorization system.

[0014] It is understood here that the concept of a support corresponds to a part receiving the blades and driven in rotation around the axis of revolution. The exact shape of the support is determined so as to present a lightweight structure, which interferes minimally with the airflow, and sufficiently robust to receive the blades. The support thus extends from the body, for example, away from the axis of revolution, so as to receive the blades offset from the axis of revolution. In particular, a support consisting of a plurality of arms makes it possible to design substantially complementary shapes between the arms and the blades in the deployed position. Preferably, the blades deploy below or above the support, i.e., the arms, the disc, or the ring, preferably below the support.

[0015] In other words, the blades are assembled offset from the axis of revolution of the body, and the pivot is positioned at a distance from the first and second ends, so that the blades extend both outwards from the fan via the second end and inwards from the fan via the first end. For example, in the folded position, the blades are arranged in a ring around, below, or above the body, the ring being connected to the body via the support, for example, via the arms. Preferably, the blades are arranged around the body, as stresses on the body are reduced when the support is separate from the body, allowing for a smaller design.

[0016] It is understood here that the intermediate portion corresponds to a section of the blade located at a considerable distance from the first end, unlike the conventional design of retractable blades, which are attached to the body by means located near the first end. The intermediate portion is, for example, located at a distance from the first end greater than at least one-fifth of the blade length.

[0017] Thus, when the fan is started to rotate, the support is driven by the drive system and transmits the rotational motion to the blades, which are simultaneously driven to move into the second position so as to generate an airflow. The support may, for example, form a single unit driven by the drive system. In another example, the support may be made of a plurality of parts, for example, a plurality of independent arms, each arm being independently indexed to a motor block of the drive system, so as to drive them separately.

[0018] The Applicant submits that this design makes it possible to obtain a compact folded form, in which the blades can, in particular, have the appearance of a lampshade around the central body, rather than resting on the central body. This design This greatly reduces the stress on the central body, which can be smaller. In the extended position, the blades extend from the central body similarly to a conventional ceiling fan, and offer comparable performance. Furthermore, the blades are positioned closer to the axis of rotation in the extended position, thus limiting the overall size of the ceiling fan while maintaining the same performance as prior art fixed-blade ceiling fans.

[0019] The Applicant submits that the airflow of the fan according to the present invention is increased by approximately 50% compared to a conventional retractable blade fan, and approaches the performance of a standard non-retractable fan. Furthermore, the reduction in the size of the central body limits the product's mass and therefore the associated manufacturing and transportation costs.

[0020] Thanks to the present invention, it is therefore possible to design a ceiling fan which retains the performance of a conventional fan in its deployed position, while having a distinct appearance in its folded position, in particular the appearance of a decorative light fixture.

[0021] In an advantageous embodiment of the present invention, the rotation of the fan causes the blades to move from the first position to the second position, and stopping the fan causes the blades to move from the second position to the first position.

[0022] In other words, the fan is configured so that the deployment and retraction of the blades are not controlled, but result naturally from the rotation of the fan. The rotation around the axis of revolution causes, for each blade, a rotation around the pivot.

[0023] The fan is for example configured so that the blades reach the second position when the rotation speed reaches about 50 revolutions per minute, so as to guarantee full deployment at 70 revolutions per minute, corresponding to a low operating speed for a fan.

[0024] According to another example, the fan is equipped with means for synchronizing the deployment of the blades. Such means take, for example, the form of a spacer between each blade, particularly as described in documents EP2388483B1 and EP2400158B1. This design ensures that the blades deploy and retract simultaneously, but is likely to increase the weight of the structure, as well as to form a visual obstacle and / or an obstruction to airflow.

[0025] One way of implementing a transition of the blades from the first position to the second position resulting from the rotation of the fan is to configure the blades so that the rotation creates an imbalance of forces along the blade, i.e. that the forces applied, in particular due to the centrifugal force, are unequal on either side of the pivot.

[0026] Preferably, for each of the blades, the intermediate portion is offset from a longitudinal center of the blade, so that the rotation of the fan creates an imbalance of forces along the blade causing the blades to move from the first position to the second position.

[0027] It is understood here that rotating the fan applies a centrifugal force along the blades. It is further understood in this text that the position of the intermediate portion corresponds to the pivot point, that is, the point at which the blade is joined to the arm. The intermediate portion thus delineates two parts of the blade, and offsetting the intermediate portion from the center of the blade allows an additional force to be applied to the longer part of the blade relative to the shorter part. The intermediate portion is, for example, closer to the proximal end than to the distal end.

[0028] In another embodiment, for each blade, the intermediate portion is longitudinally centered on the blade, forming two halves of the blade. The first half of the blade has a lower mass than the second half, so that the rotation of the fan creates an imbalance of forces along the blade, causing the blades to move from the first position to the second position. This central position of the intermediate portion may allow for a certain tolerance, particularly due to the shape of the blades and the implementation of the pivot joint.

[0029] It is understood here that, in this design, the blade does not have a regular profile, but is instead designed so that the second half of the blade is heavier than the first half, resulting in a different centrifugal force between the first and second halves, and therefore a pivoting around the intermediate portion. The second half, for example, has a greater thickness or width than the first half, or is equipped with a counterweight allowing for precise adjustment of the applied forces, independent of the shape of the blade. The second half corresponds, for example, to the portion of the blade extending between the intermediate portion and the distal end, and the first half corresponds, for example, to the portion of the blade extending between the intermediate portion and the proximal portion.

[0030] Obviously, it is possible to conceive of a multiplicity of blade design variants resulting in an imbalance of forces along the blade, in particular an imbalance of forces on either side of the intermediate portion, notably by creating a difference in dimensions and / or weight on each side of the intermediate portion.

[0031] In an additional embodiment, the fan further comprises a set of elastic means between the blades and the body, the elastic means being configured to drive the blades to the first position during fan shutdown.

[0032] In other words, in the absence of external action, particularly centrifugal force generated by the fan's rotation, the elastic means move the blades to a rest position corresponding to the first position. Naturally, the elastic means are also dimensioned so that the centrifugal force generated by the fan's rotation is sufficient to move the blades to the second position, despite the opposing action of the elastic means.

[0033] The Applicant submits, in particular, that the use of elastic means allows for a more gradual deployment and retraction of the blades, ensuring quiet operation. The elastic means may, in particular, consist of a system of torsional and / or compression and / or tension springs. The use of such elastic means is described in particular in documents CN212672083U, EP1904793B1 and EP2400158B1.

[0034] It is also possible to design a fan whose blades automatically return to the folded position when the fan is stopped, by other means. Document CN113187745A discloses in this regard a natural folding of the blades under their own weight when the fan is stopped.

[0035] In an additional embodiment, the blades are arranged around the body, and the first end of each of the blades has a shape complementary to the body so that, when the blades are in the second position, the first end is fitted against the body.

[0036] In other words, the first end of each blade fits snugly against the body, so as to avoid or minimize any gap between the blade and the body when the blades are deployed. This design allows the blades to be positioned in line with the body and prevents any air from rising between the blades and the body, thereby optimizing the flow rate and achieving a shape as close as possible to that of a conventional fan.

[0037] It is further understood that the blades are arranged at approximately the same height as the body against which they are fitted, unlike conventional designs of retractable bladed fans, in which the blades are arranged above the body, the body supporting the blades and all the means enabling the blades to be articulated. This design makes it possible to ensure a shape and operation similar to those of a conventional fixed-bladed fan.

[0038] In an embodiment that can be combined with the preceding embodiments, the blades and the support have complementary shapes so that, when the blades are in the second position, the blades form an extension of the support.

[0039] It is understood here that this design corresponds to an adjustment of the blades against the support in the second position, which can be implemented in a variety of ways depending on their respective positions. In one particular example, when the blades are deployed, the support covers the blades. Positioning the blades in line with the support minimizes any interference of the support with the airflow, and thus ensures good ventilation performance. This design is also particularly advantageous when the support comprises a plurality of arms, each arm covering the blade to which it is attached.

[0040] In one embodiment, the blades are dimensioned to overlap at least partially between adjacent blades in the first position.

[0041] In other words, the blades fold onto each other, so as to obtain a more compact shape relative to the diameter of the fan once the blades are deployed.

[0042] It is further understood that a person skilled in the art can dimension the blades so that they overlap in the folded position, or so that there is a gap between two adjacent blades in the folded position. Thus, this design makes it possible to obtain a wide variety of combinations between the shape of the fan in the folded position and the dimensions in the extended position.

[0043] In yet another embodiment, the blades pivot about an oblique axis relative to the axis of revolution, so that between the first position and the second position, the blades have an inclination about an axis perpendicular to the axis of revolution.

[0044] In other words, rather than pivoting about an axis substantially parallel to the axis of revolution, the blades pivot about an oblique axis, or even about a combination of a first axis parallel to the axis of revolution and a second axis perpendicular to the axis of revolution. For example, the blades extend in a plane perpendicular to the axis of revolution in the folded position, and are inclined relative to this plane in the deployed position.

[0045] Pivoting about an oblique axis is implemented, for example, via an assembly that directly allows pivoting about such an axis, or via an assembly that allows combined movement about two axes as described above. Document CN109826812A discloses, in this regard, a double-hinge system that allows each blade to rotate about two axes in order to deploy.

[0046] In a specific embodiment, the blades have a first flat portion according to which the blade is assembled with the arm, and a second portion extending from the first portion so as to define the profile of the blade.

[0047] It is understood here that the first portion allows the blade to be received on the fan and preferably has minimal dimensions to reduce the impact on the airflow, while the second portion is sized to generate the airflow during the rotation of the blade. The first portion extends, for example, in a plane substantially parallel to the blade arms. The second portion may be at right angles to the first portion or inclined, depending on the fan design. The first portion is also sized, for example, to ensure that the blades form an extension of the blade arms, in particular so that the blade arms cap the blades.

[0048] Thus, through the various functional and structural technical characteristics above, the Applicant proposes a ceiling fan combining the advantages of a fan with retractable blades while approaching the ventilation performance of a conventional fan. Description of the figures

[0049] Other features and advantages of the present invention will become apparent from the description of the particular and non-limiting embodiments of the present invention below, with reference to the attached Figures 1 to 11, in which:

[0050] [Fig.1]

[0051] Fig. 1 schematically illustrates a first perspective view of a ceiling fan according to a first embodiment of the present invention, in the folded position;

[0052] [Fig.2]

[0053] [Fig.2] schematically illustrates a second perspective view of a ceiling fan conforming to [Fig.1], in the folded position;

[0054] [Fig.3]

[0055] [Fig.3] schematically illustrates a top view of a ceiling fan conforming to [Fig.1], in transition between the folded position and the deployed position;

[0056] [Fig.4]

[0057] [Fig.4] schematically illustrates a top view of a ceiling fan conforming to [Fig.1], in the deployed position;

[0058] [Fig.5]

[0059] Fig. 5 schematically illustrates a first perspective view of a ceiling fan according to a second embodiment of the present invention, in the deployed position;

[0060] [Fig.6]

[0061] Fig. 6 schematically illustrates a second perspective view of a ceiling fan conforming to Fig. 5, in the deployed position;

[0062] [Fig.7]

[0063] Fig. 7 schematically illustrates a perspective view of a ceiling fan according to a third embodiment of the present invention, in the folded position;

[0064] [Fig.8]

[0065] [Fig.8] schematically illustrates a perspective view of a ceiling fan conforming to [Fig.7], in the deployed position;

[0066] [Fig.9]

[0067] Fig. 9 schematically illustrates a profile view of a ceiling fan according to a fourth embodiment of the present invention, in the deployed position;

[0068] [Fig. 10]

[0069] Fig. 10 illustrates a first representative graph of velocity fields in a vertical cross-section plane of a conventional ceiling fan of the prior art;

[0070] [Fig. 11]

[0071] Figure 11 illustrates a second representative velocity field graph in a vertical cross-sectional plane of a ceiling fan according to the present invention. Detailed description

[0072] A ceiling fan will now be described in what follows with joint reference to Figures 1 to 11. The same elements are identified with the same reference signs throughout the description that follows.

[0073] As indicated in the preamble to the description, retractable blade fans suffer from reduced efficiency compared to conventional fans, due to a design that reduces their airflow.

[0074] One of the objectives of the present invention is to provide a ceiling fan with retractable blades that retains the advantages of a retractable design while having ventilation performance comparable to conventional fans.

[0075] This is made possible in the example described below.

[0076] As illustrated in Figures 1 to 9, the example described herein provides a ceiling fan 1 comprising a central body 11 and a plurality of blades 12, the blades 12 being able to move between a first position, referred to as the folded position (Figures 1, 2 and 7), and a second position, referred to as the extended position (Figures 4 to 6, 8 and 9). Figure 3 illustrates a transition position between the first and second positions. In this example, the blades 12 are arranged around the body 11.

[0077] The fan 1 includes a motorization system, preferably integrated into the central body 11, so as to drive the fan 1 in rotation about an axis Z, the structure of the fan 1 substantially defining the axis Z as an axis of revolution. In the second position, the blades 12 extend between a first end 121, closest to the axis of revolution Z, and a second end 122, furthest from the axis of revolution Z. Thus, when the blades 12 are in the deployed position, the rotation of the fan 1 generates an airflow.

[0078] In particular, the fan 1 may include a plurality of conventional means known to ceiling fans. The fan 1 here includes means 111 for fixing to the ceiling, assembled with the body 11. The central body 11 may or may not house a central light. In some designs, the central body 11 comprises exclusively the motor system, so as to minimize its volume. Furthermore, the designs described here consider a fan with three blades 12, but it is possible to adapt the design for any number of blades greater than or equal to two.

[0079] Advantageously, the fan 1 further comprises a support 13, here in the form of a plurality of arms 13, in particular one arm 13 per blade 12. Each arm 13 extends from the body 11, away from the axis of revolution Z, is driven by the motorization system around the axis of revolution Z, and is assembled with a blade 12. The arms 13 form, for example, as illustrated in [Fig. 1], a single unit driven by the motorization system. The assembly between the blade 12 and the arm 13 takes place at an intermediate portion 123 of the blade 12, that is to say at a distance from the first end 121 and the second end 122, and forms a pivot 131. In other words, the arm 13 transmits the rotational movement to the blade 12 around the axis of revolution Z, and the blade 12 can pivot relative to the arm 13 so as to pass between the first position and the second position.

[0080] The assembly between the blade 12 and the arm 13 being carried out at an intermediate portion 123, between the first end 121 and the second end 122, and at a distance from the axis of revolution Z, the transition to the second position corresponds to a movement of the first end 121 towards the axis of revolution Z, while at the same time the second end 122 moves away from the axis of revolution Z. In this same example, the first end 121 moves away from the body 11 while the second end 122 moves towards the body 11, the blades 12 being arranged around the body 11. In other words, the deployment of the blades 12 takes place both inwards and outwards. This design is thus distinguished from conventional retractable blade fans, in which only the second end 122 extends outwards, the first end 121 being fixed to the body 11.Furthermore, in the first position, the blades 12 remain at a distance from the body 11, for example in the form of a ring around the body 11, the first end 121 and the second end 122 being substantially equidistant from the body 11, rather than folded over the . body 11. This folded shape thus allows the advantages of retractable blade fans to be retained, including a certain compactness as well as their aesthetic advantages by presenting a distinct appearance from a fan when stopped.

[0081] Advantageously, as illustrated in Figures 1, 3 to 5 and 7 to 9, the blades 12 comprise a first substantially flat portion 124, according to which the blade 12 is assembled with the arm 13. In other words, the first portion 124 receives the pivot 131. The first portion 124 thus extends, for example, in a plane perpendicular to the axis of the pivot 131, which is preferably parallel to the axis of revolution Z. The blades 12 also comprise a second portion 125, which extends from the first portion 124 and defines the profile of the blade 12, which is established primarily according to aerodynamic and / or aesthetic criteria. The second portion 125 extends, for example, obliquely with respect to the first portion 124, for example, like an inclined right angle, at an angle between 120 and 150 degrees.

[0082] The shape and design of the blades 12 can also be adapted according to a variety of designs remaining within the scope of the present invention. Figures 4, 5, 8, and 9 thus illustrate four variants of the fan 1 in the deployed position. In particular, the blades 12 can pivot, between the first and second positions, through a greater or lesser angle depending on their dimensions, their number, and their exact arrangement in the folded and deployed positions.

[0083] As illustrated in Figures 7 and 8, the blades 12 are dimensioned such that each blade 12 overlaps another adjacent blade 12 in the folded position. In other words, the second end 122 of each blade 12 overlaps at least the first end 121 of an adjacent blade. It is understood that the overlapping order of the blades 12 is necessary to allow them to pivot without collision, that is, so that the first end 121 can move closer to the axis of revolution Z and the second end 122 can move away from the axis of revolution Z, starting from the first position. This design thus makes it possible to reduce the diameter of the fan 1 in the folded position, and the size of the arms 13, and / or to increase the diameter of the fan 1 in the deployed position, and therefore the airflow.

[0084] Alternatively, when the blades 12 do not overlap, particularly as illustrated in Figures 1 and 2, the blades 12 are dimensioned so that the second end 122 of each blade 12 is in the vicinity of the first end 121 of the adjacent blade 12. This design may also provide clearance to facilitate the deployment of the blades 12.

[0085] In another example illustrated by Figures 3 and 4, the first end 121 of each blade 12 has a shape complementary to the body 11, that is to say, to a portion of the body 11. The first end 121 then fits snugly against the body 11 in the second position, as illustrated in [Fig.4]. The approach of the first end 121 towards the axis of revolution Z then stops when the first end 121 fits the body 11.

[0086] In this same example, each blade 12 also has a complementary shape to each branch 13 and extends, in the second position, in the continuation of each branch 13. As illustrated in [Fig.4], the branch 13 comes to cap the blade 12, in particular the first portion 124, that is to say that the blade 12 extends beyond the branch 13, below the branch 13.

[0087] In yet another embodiment illustrated in [Fig.9], the blades 12 have, in the second position, an inclination with respect to the horizontal, that is to say with respect to an axis perpendicular to the axis of revolution Z. Each pivot 131 is for example articulated with respect to an axis oblique to the axis of revolution Z, or composed of a plurality of articulations allowing a first rotation with respect to a first axis parallel to the axis of revolution Z, and a second rotation with respect to a second axis perpendicular to the axis of revolution Z.

[0088] Just as it is possible to adapt the articulation of the blades 12 with respect to the arms 13, it is also possible to design a plurality of variants for implementing the deployment and / or folding of the blades 12.

[0089] It is advantageous, for example, that the rotation of the fan 1, i.e., the operation of the drive system to rotate the arms 13 and the blades 12, directly results in the blades 12 moving from the first position to the second position. The second position is reached, for example, at a rotational speed of approximately 50 revolutions per minute or less. Such designs generally rely on the natural centrifugal force generated by the rotation to deploy the blades 12. Additionally, it is also provided that stopping the rotation directly results in the blades 12 moving from the second position to the first position. The first position corresponds, for example, to a rest position in the absence of centrifugal force.

[0090] In the example of Figures 3 and 4, the intermediate portion 123, and by extension the pivot 131, is thus offset from the longitudinal center of the blades 12. The portion of each blade 12 extending between the intermediate portion 123 and the first end 121 (i.e., the first half of each blade 12) is therefore lighter than the rest of the blade 12 (i.e., the second half of each blade 12), between the intermediate portion and the second end 122, and the centrifugal force generated by the rotation is greater on the heavier portion, resulting in a movement away from the second end 122 and, by pivoting, a movement towards the first end 121. Obviously, it is also possible to obtain the same result with another geometry of the blade 12, in particular with an intermediate portion 123 centered longitudinally on the blade 12, provided that the portion of the blade 12 equipped with the second end 122 (or second half) is heavier than the portion of the blade 12 equipped with the first end 121 (or first half), the two portions being separated by the pivot 131.

[0091] This design can be complemented by other elements known to those skilled in the art in the manufacture of fans with retractable blades, in particular: - the implementation of a device for synchronizing the opening and / or closing of the blades 12, for example via spacers connecting each blade 12; and / or - the addition of elastic means dimensioned to drive the blades 12 towards the first position when the fan is stopped, the elastic means being dimensioned so as not to prevent the deployment of the blades beyond a certain speed, i.e. to apply a force less than the centrifugal forces expected during the rotation of the fan 1; and / or - an assembly of the blades 12 on the arms 13 so that the blades 12 return to the first position under the action of their own weight, for example in combination with an implementation of the pivot 131 transforming the action of gravity into a folding movement.

[0092] The Applicant submits that the retractable blade fan according to the present invention has aerodynamic characteristics comparable to those of a conventional fan. The first graph 2 of [Fig. 10] thus represents the velocity fields 21, in m / s, in a vertical cross-sectional plane located in the middle of a conventional fan 1'. At a speed of 150 revolutions per minute, such a conventional fan 1' achieves a flow rate of approximately 10,500 m³ / h. By comparison, the second graph 3 of [Fig. 11] represents the velocity fields 31, in m / s, in a vertical cross-sectional plane located in the middle of a retractable blade fan 1 according to the present invention. At a speed of 150 revolutions per minute, the fan 1 according to the present invention achieves a flow rate of approximately 9,500 m³ / h.It thus appears that the fan 1 according to the present invention manages to reproduce an airflow comparable to that of a conventional fan 1', and a flow rate much closer to that of a conventional fan 1' than of retractable blade fans according to the prior art. Indeed, as stated with regard to the prior art, known retractable blade fans have an airflow rate reduced by 40% compared to a conventional fan 1', i.e., in this case, a flow rate of only about 6000 m³ / h.

[0093] Thus, it will be understood that the present invention provides for a ceiling fan with retractable blades whose blade assembly has been revised so as to retain the possibility of folding and unfolding the blades, while allowing a greatly improved airflow approaching the performance of a conventional fan.

[0094] It should be noted that this detailed description relates to a particular embodiment of the present invention, but in no way does this description limit the scope of the invention; on the contrary, its purpose is to remove any possible inaccuracy or misinterpretation of the following claims.

[0095] In particular, in the examples described above, the arms 13 support the blades 12; it would be possible to design a ceiling fan 1 according to the invention in which the support is different from the arms 13 or includes other structural elements in addition to the arms 13. For example, the arms 13 could be replaced by a perforated disc driven in rotation about the axis of revolution Z by the body 11, the pivots 131 being implemented between the blades 12 and a peripheral portion of the disc, at regular intervals along the disc. According to another example, the distal ends of the arms 13 could receive a ring, the pivots 131 being implemented between the ring and the blades 12.Furthermore, the examples described above consider blades 12 arranged around the body 11, but it is also possible to design blades 12 arranged below or above the body, provided that they are assembled along their intermediate portion.

[0096] It should also be noted that the reference signs in parentheses in the following claims are in no way intended to be limiting; these signs are solely intended to improve the intelligibility and understanding of the following claims and the scope of the protection sought.

Claims

Demands

1. Ceiling fan (1) comprising a central body (11) defining an axis of revolution (Z) of said fan (1), a plurality of blades (12) assembled to said body (11) and a drive system configured to rotate said blades (12) about said axis of revolution (Z), said blades (12) being configured to move between a first position, called retracted, corresponding to a stop of said fan (1), and a second position, called deployed, corresponding to a rotation of said fan (1), said blades (12) each extending between a first proximal end (121) of said axis of revolution (Z) and a second distal end (122) of said axis of revolution (Z) in said second position, characterized in that said fan (1) comprises a support (13) extending from said body (11) and driven by said drive system,Each of said blades (12) being assembled with said body (11) via said support (13) according to an intermediate portion (123) of said blade (12), said intermediate portion (123) being mounted for rotation relative to said support (13) so as to form a pivot (131) around which said blade (12) pivots to pass between said first position and said second position, said pivot (131) being away from said axis of revolution (Z), so that said passage from said first position to said second position corresponds to a bringing of said first end (121) towards said axis of revolution (Z) and a moving of said second end (122) away from said axis of revolution (Z).

2. Fan (1) according to claim 1, wherein said rotation of said fan (1) causes said blades (12) to pass from said first position to said second position, and said stopping of said fan (1) causes said blades (12) to pass from said second position to said first position.

3. Fan (1) according to claim 2, wherein, for each of said blades (12), said intermediate portion (123) is offset from a longitudinal center of said blade (12), such that said rotation of said fan (1) creates an imbalance of forces along said blade (12) causing said blades (12) to move from said first position to said second position.

4. Fan (1) according to claim 2, wherein, for each of said blades (12), said intermediate portion (123) is longitudinally centered on said blade (12), forming two halves of said blade (12), a first half of said blade (12) having a mass less than a second half of said blade (12), such that said rotation of said fan (1) creates an imbalance of forces along said blade (12) causing said blades (12) to move from said first position to said second position.

5. Fan (1) according to any one of claims 2 to 4, further comprising a set of elastic means between said blades (12) and said body (11), said elastic means being configured to drive said blades (12) towards said first position during said stop of said fan (1).

6. Fan (1) according to any one of claims 1 to 5, wherein said blades (12) are arranged around said body (11), and said first end (121) of each of said blades (12) has a shape complementary to said body (11) so that, when said blades (12) are in said second position, said first end (121) is fitted against said body (11).

7. Fan (1) according to any one of claims 1 to 6, wherein said blades (12) and said support (13) have respectively complementary shapes such that, when said blades (12) are in said second position, said blades (12) form an extension of said support (13).

8. Fan (1) according to any one of claims 1 to 7, wherein said blades (12) are dimensioned to overlap at least partially between adjacent blades in said first position.

9. Fan (1) according to any one of claims 1 to 8, wherein said blades (12) pivot about an oblique axis with respect to said axis of revolution (Z), such that between said first position and said second position, said blades (12) have an inclination about an axis perpendicular to said axis of revolution (Z).

10. Fan (1) according to any one of claims 1 to 9, wherein said blades (12) have a first flat portion (124) according to which said blade (12) is assembled with said arm (13), and a second portion (125) extending from said first portion (124) so ​​as to define the profile of said blade (12).

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