Abstract:
The invention concerns a removable impeller ( 7 ) designed to be integrated in a fan ( 1 ), in particular for controlled mechanical ventilation, and configured in the shape of a wheel provided with a plurality of blades ( 8 ) and equipped with locking means to enable its being fixed on a hub. The invention is characterized in that it comprises projecting transmitting means, arranged proximate a central neck whereof the axis of revolution is parallel to that of the wheel, and designed so as to enable the locking means to be alternately engaged or released. The invention also concerns a fan comprising such an impeller.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates to a removable impeller designed to be incorporated into a fan, particularly for controlled mechanical ventilation, and made in the form of a wheel furnished with a plurality of blades and fitted with locking means to allow it to be attached to a hub, and a hub and a latch designed to interact with said impeller. 
       BRIEF DESCRIPTION OF RELATED ART 
       [0002]    Many systems, such as for example hygrometrically adjustable opening systems used in controlled mechanical ventilation, require the use of a fan providing air suction that is constant over time. This constant suction may be obtained at a reduced cost by regulating the speed of a motor driving an impulse impeller. Nevertheless, the disadvantage of such an impulse impeller is that it is sensitive to clogging by the dust and grease contained in the extracted air. 
         [0003]    A first known solution to overcome this problem consists in permanently attaching the impeller to the associated motor, and placing a filter upstream of the fan. However, this filter creates a loss of pressure that is unfavorable to the efficiency of the system, is bulky, is of no small cost, and needs to be changed or cleaned regularly. 
         [0004]    A second known solution consists in the use of a removable impeller, capable of being cleaned once removed. The systems fitted with such an impeller provide for the latter to be attached by screwing to a shaft. This step is nevertheless relatively awkward to carry out, particularly in the case of controlled mechanical ventilation since the occupant of the dwelling himself carries out the removal and the cleaning. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The invention remedies these disadvantages and for this purpose comprises a removable impeller designed to be incorporated into a fan, particularly for controlled mechanical ventilation, and made in the form of a wheel furnished with a plurality of blades and fitted with locking means to allow it to be attached to a hub, characterized in that it comprises protruding transmission means positioned close to a central neck whose axis of revolution is parallel to that of the wheel, and designed so as to alternately allow the engagement or extraction of the locking means. 
         [0006]    According to a first preferred embodiment of the invention, the locking means are arranged in the central neck in the form of a first series of locking clips evenly spaced from one another and each provided at the bottom with a radial swelling oriented outward. In addition, each locking clip preferably has at the bottom a radial shoulder oriented inward. 
         [0007]    Advantageously, the transmission means are arranged in the central neck in the form of a second series of transmission clips evenly spaced from one another and interspersed with the locking clips, each transmission clip being fitted with a first stop and a second stop positioned one beneath the other and oriented inward, said first stop forming a more pronounced protrusion than the second stop. 
         [0008]    Again advantageously, the first stop is arranged at the top, and the second stop is made in the form of a longitudinal boss extending in the mid-portion, and extended by an inclined face at each of its top and bottom ends. 
         [0009]    The present invention also relates to a hub and to a latch designed so as to be able to interact with such an impeller. The hub preferably comprises a lateral wall in which a series of notches is made, each of them being capable of housing one of the locking means of the impeller, and the latch comprises a gripping member and means capable of sliding through the central neck of the impeller. Again preferably, the gripping member is extended by a series of longitudinal flat walls interspersed with a series of longitudinal hollow walls, said flat walls and hollow walls being evenly spaced from one another and being capable of sliding through the central neck of the impeller. 
         [0010]    In such a configuration, it is then possible to carry out sequenced opening and closing. 
         [0011]    Specifically, when the operator applies a sufficient pull to the gripping member of the latch, the transmission clips having a greater radial stiffness than that of the hollow walls, each hollow wall sustains an elastic deformation so that the bottom portion of its contour is made to slide successively along the inclined bottom face, the boss, and finally the top inclined face of the second stop. The hollow wall then returns to its rest position in the gap separating the first stop from the second stop, and the bottom portion of the contour finally comes into contact with the first stop. This being so, the flat walls of the latch are no longer positioned facing the locking clips, and the latter may be extracted from the notches presented by the hub if the operator continues to exert a sufficient pull on the gripping member. The impeller and its latch are then separated from the hub, and it is possible to clean the blades of the impeller. This removal is therefore carried out in a single, two-stage movement simply, rapidly and toollessly. 
         [0012]    Once the impeller is properly cleaned, the operator takes the gripping member of the latch and correctly positions the impeller on its hub. All that is necessary then is to exert a sufficient push on the gripping member to force the bottom portion of the contour of each hollow wall to slide successively along the top inclined face, the boss, and finally the bottom inclined face. This being so, each flat wall of the latch slides along the associated locking clip, until the bottom end of its contour butts against the radial shoulder of the locking clip. This then has the effect of elastically deforming the locking clip outward so that its radial swelling is conveniently housed in the corresponding notch. This locking is therefore also carried out simply, rapidly and toollessly. 
         [0013]    According to a preferred variant embodiment of the invention, the impeller comprises, on the periphery of the central neck, a central wall on which longitudinal ribs are made that are evenly spaced and oriented inward. In addition, the lateral wall of the hub is advantageously fitted on its outer face with V-shaped indexing means. Therefore, with such an arrangement, when the latch and the impeller are fitted to the associated hub, a sufficient push exerted on the gripping member, that is transmitted to the top inclined face of each second stop via the bottom portion of the contour of the corresponding hollow wall of the latch, makes it possible to automatically center the impeller on the hub. Specifically, this results from the fact that the top inclined face is designed so that the minimal stresses that need to be exerted by the longitudinal ribs of the impeller on the V-shaped indexing means to force the hub to pivot until it is perfectly oriented are less than those needed to cause the elastic deformation of each hollow wall because of the sliding of the bottom portion of its contour along said corresponding top inclined face. However, once the impeller is correctly positioned in abutment against the hub, the continued push exerted by the operator on the gripping member then has the effect of forcing the latch to slide through the central neck, until it locks the locking clips in the associated notches by means of its flat walls. 
         [0014]    Once the impeller has been locked, the impeller is rotated by the hub by means of the longitudinal ribs. 
         [0015]    The impeller, the latch and the hub are advantageously made of plastic molded parts. 
         [0016]    According to a second preferred embodiment of the invention, the locking means comprises at least two magnets, and the transmission means comprises at least two link rods each comprising a first substantially cylindrical end having a longitudinal ridge forming a stop, and connected via a stem to a second protruding end parallel to the shaft of the first end. 
         [0017]    The present invention also relates to a latch designed so as to interact with an impeller according to the second preferred embodiment of the invention. This latch advantageously comprises a gripping member extended by a longitudinal stem in which a circular groove is made. 
         [0018]    The second end forming a protrusion of each link rod is housed in the circular groove of the latch so that the translation of the latter forces the first end of the link rod to start rotating. 
         [0019]    Consequently, both in the first and the second preferred embodiment of the invention, it should therefore be well understood that the impeller and the latch may be extracted and put back in place by a single movement, simply, rapidly, without training and toollessly. 
         [0020]    The present invention also relates to a fan particularly for controlled mechanical ventilation, comprising a body forming a volute in which a rotary motor is attached, a hub being fixedly attached to said motor and supporting a removable impeller provided with a central neck, a plurality of blades and fitted with locking means to allow it to be attached to the hub, characterized in that,
       the locking means are made in the central neck in the form of a first series of locking clips evenly spaced from one another and each provided at the bottom, on the one hand, with a radial swelling oriented outward, and, on the other hand, with a radial shoulder oriented inward,   the impeller comprises transmission means made in the central neck in the form of a second series of clips evenly spaced from one another and interspersed with the locking clips, each transmission clip being fitted with a first stop and a second stop positioned one beneath the other and oriented inward, said first stop forming a more pronounced protrusion than the second stop, said first stop being made at the top and said second stop being made in the form of a longitudinal boss, extending in the mid-portion, respectively extended by a steeply inclined face at its top end and by a slightly inclined face at its bottom end,   the hub comprises a lateral wall in which a series of notches is made, each of them being capable of housing one of the locking clips of the impeller,   a latch is fitted to the impeller, this latch comprising a gripping member extended by a series of longitudinal flat walls interspersed with a series of longitudinal hollow walls, said flat walls and hollow walls being evenly spaced from one another and being capable of sliding through the central neck so that each is respectively placed facing a locking clip and a transmission clip.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention will be better understood with the aid of the detailed description that is given below with respect to the appended drawing in which: 
           [0026]      FIG. 1  is a view in perspective of a fan according to the invention, with the cover omitted; 
           [0027]      FIG. 2  is a top view in perspective of an impeller according to a first preferred embodiment of the invention; 
           [0028]      FIG. 3  is a bottom view in perspective of the impeller shown in  FIG. 2 ; 
           [0029]      FIG. 4  is a view in perspective of a latch according to the invention capable of interacting with the impeller shown in  FIG. 2 ; 
           [0030]      FIG. 5  is a view in perspective of a hub according to the invention capable of interacting with the impeller shown in  FIG. 2 ; 
           [0031]      FIG. 6  is a view in perspective of the impeller shown in  FIG. 2  with its latch, before attachment to its corresponding hub; 
           [0032]      FIG. 7  is a top view of the impeller shown in  FIG. 6 , once attached to its hub; 
           [0033]      FIG. 8  is a view in section along the line A-A of the assembly shown in  FIG. 7 , the latch being in the closed position; 
           [0034]      FIG. 9  is a view in section along the line B-B of the assembly shown in  FIG. 7 , the latch being in the closed position; 
           [0035]      FIG. 10  is a view in section along the line A-A of the assembly shown in  FIG. 7 , the latch being in the open position; 
           [0036]      FIG. 11  is a view in section along the line B-B of the assembly shown in  FIG. 7 , the latch being in the open position; 
           [0037]      FIG. 12  is a view in perspective of an impeller according to the second preferred embodiment, with the link rods omitted; 
           [0038]      FIG. 13  is a view in perspective of a link rod; 
           [0039]      FIG. 14  is a view in perspective of a latch according to the invention capable of interacting with the impeller shown in  FIG. 12 ; 
           [0040]      FIG. 15  is a view in perspective of a hub according to the invention capable of interacting with the impeller shown in  FIG. 12 ; 
           [0041]      FIG. 16  is a view in perspective of a half of the impeller shown in  FIG. 12 , cut longitudinally at the link rods, before attachment to its corresponding hub; and 
           [0042]      FIG. 17  is a view in perspective of another half of the impeller shown in  FIG. 12 , cut longitudinally at the magnets, before attachment to its corresponding hub. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0043]    A fan  1  according to the invention, as shown in  FIG. 1 , is designed for controlled mechanical ventilation and comprises a casing  2  whose cover has been omitted, and in which a volute  3  is attached. 
         [0044]    The casing  2  has four air inlet connectors  4  and each of them is placed in relation with a room of the dwelling to be ventilated by means of an aeration duct (not shown). 
         [0045]    The volute  3  is made of plastic and conventionally comprises an air inlet  5  and an air outlet  6 , the air inlet  5  being bordered by a removable ear  60  attached with the aid of clips (not shown). 
         [0046]    As shown more specifically in  FIGS. 1 to 3 , the volute  3  contains an impeller  7 , according to a first preferred embodiment of the invention, provided to create suction in the casing  1  so as to aspirate the contaminated air originating from the air inlet connectors  4 . This impeller  7  is molded in plastic in the shape of a wheel fitted with a plurality of blades  8 , and comprises a central wall  9  that is axisymmetric surrounding a central neck  10  whose vertical axis of revolution is indistinguishable from that of the wheel. 
         [0047]    Again more precisely, four vertical locking clips  11  evenly spaced from one another are made in the central neck  10  of the impeller  7 . Each locking clip  11  has at the bottom, on the one hand, a radial swelling  12  oriented outward, and, on the other hand, a radial shoulder  13  oriented inward. 
         [0048]    In addition, four vertical transmission clips  14  evenly spaced from one another, interspersed with the locking clips  11  of the same length as the latter but wider so as to present increased resistance to radial deformation, are also made in the central neck  10 . 
         [0049]    Each transmission clip  14  is fitted with a first stop  15  and a second stop  16  oriented inward and made at a certain distance one beneath the other, said first stop  15  forming a more pronounced protrusion than the second stop  16 . The first stop  15  is made in the top of the central neck  10 , and the second stop  16  is made in the form of a vertical boss  17 , extending in the mid-portion of the central neck  10 , and extended by an inclined face  18 ,  19  at each of its top and bottom ends, the top inclined face  18  being more inclined than the bottom inclined face  19 . 
         [0050]    Furthermore, four vertical ribs  20  evenly spaced from one another and oriented inward are made in the central wall  9  facing the central neck  10 . 
         [0051]    As shown in  FIG. 4 , a latch  21  according to the invention capable of interacting with the impeller  7  is molded in plastic and is divided into a gripping member  22  of diskoid shape extended by four flat longitudinal walls  24  oriented outward and interspersed with four longitudinal hollow walls  25 , said flat walls  24  and hollow walls  25  being evenly spaced from one another and of the same length. 
         [0052]    The flat walls  24  are in fact connected together by plastic so as to form a rigid subassembly in the shape of a cross in cross section, which makes it possible to prevent any radial deformation of the flat walls  24 . 
         [0053]    In addition, it should be well understood that this latch  21  is designed so that, on the one hand, the distance separating two diametrically opposed flat walls or two hollow walls is very slightly less than that separating two diametrically opposed clips of the impeller  7 , and on the other hand, the length of said flat walls  24  and hollow walls  25  is sufficient to act respectively on the swellings  12  and the shoulders  13  presented by the locking clips  11  and the transmission clips  14  of the impeller  7  when the latch  21  is inserted. 
         [0054]    As shown in  FIG. 5 , a hub  26  according to the invention, capable of interacting with the impeller  7 , is molded in plastic, and comprises a lateral wall in which four notches  27  have been made evenly spaced from one another and sufficiently wide for each to house one of the locking clips  11  of the impeller  7 . In addition, this lateral wall is fitted on its outer face with four V-shaped indexing means  28 , evenly spaced from one another. 
         [0055]    As shown schematically in  FIGS. 6 to 11 , the hub  26  is made fixedly attached to a rotary motor  29  attached in the volute  3  (not shown). 
         [0056]    When the fan  1  is installed in the dwelling of the end user, the impeller  7  and its latch  21  have previously been attached to the hub  26  at the factory. It should be noted that this latch  21  can therefore move only between two extreme positions, namely, on the one hand, as shown in  FIG. 11 , an open position in which the bottom portion  30  of the contour of each hollow wall  25  is held latched against the first stop  15  and the top inclined face  18  of the second stop  16  of the associated transmission clip  14 , and on the other hand, as shown in  FIG. 9 , a closed position in which the bottom portion  30  of the contour of each hollow wall  25  is held latched by the bottom inclined face  19  of the second stop  16  of the associated transmission clip  14 . 
         [0057]    When the user wishes to clean the impeller  7  after a certain period of time, he then acts in the following manner. 
         [0058]    First of all, he begins by unclipping the removable ear  60  by pulling thereon. 
         [0059]    Once this operation is complete, the user grasps the gripping member  22  of the latch  21  and pulls. The latch  21  which was hitherto in the closed position, as shown in  FIGS. 8 and 9 , is then made to slide upward. Specifically, the radial stiffness of the hollow walls  25  being less than that of the transmission clips  14 , the pull exerted has the effect of forcing the bottom portion  30  of the contour of each hollow wall  25  to deform elastically during the successive sliding along the bottom inclined face  19 , the boss  17 , and finally the top inclined face  18  of the transmission clip  14  placed opposite. 
         [0060]    As shown in  FIGS. 10 and 11 , each hollow wall  25  returns to its rest position when the bottom portion  30  emerges into the space separating the second stop  16  from the first stop  15 . The bottom portion  30  then comes into contact with the latter that has been designed to protrude sufficiently to form a bump stop. 
         [0061]    The continuation of the pulling movement forces the swelling  12  of each locking clip  11  to butt against the top edge of the corresponding notch  27 . Now that the flat wall  25  associated with each locking clip  11  is no longer there to serve as a radial stop, it follows that each locking clip  11  sustains a radial elastic deformation oriented inward. Each swelling  12  is finally extracted from its corresponding notch  27  under the pulling effect and the subassembly formed by the impeller  7  and the latch  21  is separated from the fan  1 . The user, who has carried out a rapid, simple and toolless removal of the impeller  7 , may then clean the blades  8  of the latter. 
         [0062]    Once the cleaning operation is complete, the user fits the subassembly formed by the impeller  7  and the latch  21  onto the associated hub  26  and exerts a sufficient vertical push on the gripping member  22 . This vertical push is transmitted to the top inclined face  18  of each second stop  16  via the bottom portion  30  of the contour of the corresponding hollow wall  25  of the latch  21  and makes it possible to automatically center the impeller  7  on the hub  26 . 
         [0063]    Specifically, this results from the fact that the top inclined face  18  is designed so that the minimal stresses that need to be exerted via the vertical ribs  20  of the impeller  7  on the V-shaped indexing means  28  to force the hub  26  to pivot about its axis until it is perfectly oriented are less than those needed to cause the elastic deformation of each hollow wall  25  because of the sliding of the bottom portion  30  of its contour along said corresponding top inclined face  18 . 
         [0064]    However, once the impeller  7  is correctly positioned in abutment against the hub  26 , the continuation of the vertical push exerted by the user then has the effect of forcing the latch  21  to slide through the central neck  10 . More precisely, the bottom portion  30  of the contour of each hollow wall  25  is made to slide successively along the top inclined face  18 , the boss  17  and finally the bottom inclined face  19 . So doing, each flat wall  24  slides along the associated locking clip  11  until the bottom end of its contour butts against the radial shoulder  13  of said locking clip  11 . This then has the effect of elastically deforming the locking clip  11  outward so that its radial swelling  12  is conveniently housed in the corresponding notch  27  of the hub  26 . This locking is therefore also carried out simply, rapidly and toollessly. 
         [0065]    Once the impeller  7  has been locked, the rotation of the latter via the hub  26  under the effect of the motor  29  is then carried out by means of the vertical ribs  20 . 
         [0066]      FIGS. 12 to 17  show an impeller  107  without its blades and according to the second preferred embodiment, and the associated latch  121  and hub  126 . 
         [0067]    The impeller  107  has a central neck  110  and differs mainly from the impeller  7  by the fact that it has at the bottom two protuberances  130 , placed facing one another on either side of the central neck  110 , each fitted with a magnet  111  forming a locking means, and each provided with a longitudinal rib  120  oriented outward. 
         [0068]    Two link rods  114  are attached in each protuberance  130  as shown more specifically in  FIGS. 16 and 17 . More precisely, each link rod  114  has a first substantially cylindrical end  131 , having a longitudinal ridge  132  forming a stop, and is connected via a stem  133  to a second protruding end  134  parallel to the shaft  135  of said first end  131 . Each link rod  114  is then made fixedly attached to the impeller  107  thanks to the shaft  135  that is housed in two bores  137 , made in the protuberances  130  and situated facing one another. 
         [0069]    The latch  121  comprises a gripping member  122  of diskoid shape extended by a stem  138  in which a circular groove  139  is made close to its bottom end. 
         [0070]    The hub  126  is made fixedly attached to a rotary motor  129  and is made in the form of a metal disk  140  having a hollow circular central portion  141  in which two nicks  142  each designed to house one of the ribs  120 , are made. 
         [0071]    The impeller  107  and the latch  121  are assembled in the hub  126  in the following manner. 
         [0072]    First of all, the second end  134  forming a protrusion of each link rod  114  is inserted into the groove  139  of the shaft  140  of the latch  121  so that the latch  121  can move only between two extreme positions, namely a closed position (not shown) and an open position shown in  FIGS. 16 and 17 . 
         [0073]    This subassembly thus formed is then fitted to the hub  126 . When the hub  121  is lowered to come into the closed position, each link rod  114  pivots about its shaft  135  in one direction forcing the ridge  132  to separate from the bottom of the disk  140 . Each link rod  114  therefore forms a transmission means allowing the magnets  111  to come into contact with the bottom of the disk  140 . 
         [0074]    When the user desires to clean the impeller  107 , he grasps the gripping member  122  and pulls thereon. Each link rod  114  is then pulled in a rotary motion in opposite directions. The ridge  132  therefore butts against the bottom of the disk  140 , which has the effect of gearing down the pulling action exerted on the gripping member  122  and makes separating the magnets  111  from the bottom of the disk  140  much easier. Each link rod  114  therefore forms a transmission means allowing the extraction of the locking means connecting the impeller  107  to the hub  126 . 
         [0075]    Although the invention has been described with reference to particular exemplary embodiments, it is evident that it is in no way limited thereto and that it covers all the technical equivalents of the means described and their combinations if the latter enter into the context of the invention.