Patent Publication Number: US-10316850-B2

Title: Ceiling fan

Description:
TECHNICAL FIELD 
     The present invention relates to a ceiling fan. 
     BACKGROUND ART 
     Conventionally, there are known various types of ceiling fans suspended from a ceiling for use. For example, the conventional ceiling fan includes a coupling portion having an upper part supported on a ceiling, a rotary driving portion attached to a lower part of the coupling portion, a plurality of blades to be rotated by the rotary driving portion, and a support portion to which root portions of the blades are attached in a mounting state. The rotary driving portion has a stator fixed to the coupling portion and a rotor to be rotary driven around the stator. The support portion is fixed to the rotor. When the rotor is rotary driven, the respective blades attached to the support portion are rotated together with the support portion. 
     The conventional ceiling fan having the structure is devised in respect of safety, for example, a blade fall preventing portion is provided so as not to separate the blades from the support portion even if the blade is broken in the root portion (see Patent Document 1, for example). 
     A structure of the blade fall preventing portion provided in the conventional ceiling fan will be described with reference to  FIG. 15  showing an attachment state to a support portion  112  in a root portion  111  of a blade  110 . As shown in  FIG. 15 , the root portion  111  of the blade  110  has a screw fastening holes  113  (two places) provided in the vicinity of both ends in a width direction and an engaging hole  114  (one place) provided on a center in the width direction. Moreover, an engaging portion  115  protruded from an upper surface is provided on the support portion  112 . 
     As shown in  FIG. 15 , the root portion  111  of the blade  110  is fastened with a screw by using the fastening holes  113  in the two places in a mounting state on the upper surface of the support portion  112 . Consequently, the blade  110  is brought into an attachment state to the support portion  112 . In the attachment state, furthermore, the engaging portion  115  of the support portion  112  penetrates the engaging hole  114  of the root portion  111  on the blade  110 . 
     In the case in which a vicinal part of the fastening hole  113  is broken in the root portion  111  of the blade  110 , for example, the engaging portion  115  is engaged with the engaging hole  114  so that the blade  110  can be prevented from falling. Referring to the conventional ceiling fan in  FIG. 15 , thus, the blade fall preventing portion is configured from the engaging portion  115  and the engaging hole  114 . 
     CONVENTIONAL ART DOCUMENT 
     Patent Document 
     Patent Document 1: WO2013/145656 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In the case in which the root portion of the blade is broken, however, a part of the root portion is placed on the support portion. For this reason, there is a problem in that an amount of suspension of the blade (an amount of downward inclination) is small and hard for a user to notice breakage of the blade at a stop time as well as at an operation time. 
     In order to solve the conventional problem, it is an object of the present invention to provide a ceiling fan capable of causing a user to clearly recognize breakage at an operation time and a stop time if a blade is broken. 
     Means for Solving the Problems 
     In order to solve the conventional problem, a ceiling fan according to an aspect of the present invention includes a coupling portion having an upper part supported on a ceiling; a rotary driving portion having a stator fixed to a lower part of the coupling portion and a rotor to be rotary driven around the stator; a plurality of blades to be rotated around a center of the rotor by the rotary driving portion; a support portion which is fixed to the rotor and to which root portions of the blades are attached in a mounting state; and a fall preventing member having a loop portion formed by a wire rod so as to be engageable with the blades and the support portion, and, in the ceiling fan, a through hole that the loop portion of the fall preventing member penetrates is provided in the root portions of the blades, the support portion is provided with an engaging portion which is engageable with the loop portion of the fall preventing member, and the loop portion of the fall preventing member is disposed to be engageable with the engaging portion of the support portion in a state that the blades are attached to the support portion, the loop portion is engaged with the engaging portion of the support portion when an attachment part of the support portion and the blades is broken, and the blades are held on the support portion through the loop portion of the fall preventing member in a state that inner edges of the root portions of the blades are positioned on an outside of an outer edge of the support portion. 
     Effects of the Invention 
     According to the present invention, it is possible to provide a ceiling fan capable of causing a user to clearly recognize breakage at an operation time and a stop time if a blade is broken. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view showing a ceiling fan according to a first embodiment of the present invention. 
         FIG. 2  is a partial enlarged view showing the ceiling fan according to the first embodiment. 
         FIG. 3  is a partial enlarged view showing an attachment part of a blade to a support portion which are provided in the ceiling fan according to the first embodiment. 
         FIG. 4  is a perspective view showing a fall preventing member provided in the ceiling fan according to the first embodiment. 
         FIG. 5  is a view showing a state in which the blade is held by the fall preventing member when the attachment part of the blade to the support portion is broken in the ceiling fan according to the first embodiment. 
         FIG. 6  is a side view showing the state in which the blade is held by the fall preventing member when the attachment part of the blade to the support portion is broken in the ceiling fan according to the first embodiment (at an operation time). 
         FIG. 7  is a side view showing the state in which the blade is held by the fall preventing member when the attachment part of the blade to the support portion is broken in the ceiling fan according to the first embodiment (at a stop time). 
         FIG. 8  is a partial enlarged view showing an attachment part of a blade to a support portion in a ceiling fan according to a second embodiment of the present invention. 
         FIG. 9  is a view showing an external appearance of a fall preventing member provided in the ceiling fan according to the second embodiment. 
         FIG. 10  is a view showing a state in which the blade is held by the fall preventing member when the attachment part of the blade to the support portion is broken in the ceiling fan according to the second embodiment. 
         FIG. 11  is a partial enlarged view showing an attachment part of a blade to a support portion in a ceiling fan according to a third embodiment of the present invention. 
         FIG. 12  is a view showing an external appearance of a fall preventing member provided in the ceiling fan according to the third embodiment in an attached state to the blade. 
         FIG. 13  is a view showing an external appearance of a fall preventing member of the ceiling fan according to the third embodiment. 
         FIG. 14  is a view showing a state in which the blade is held by the fall preventing member when the attachment part of the blade to the support portion is broken in the ceiling fan according to the third embodiment. 
         FIG. 15  is a view showing a structure of a blade fall preventing portion provided in a conventional ceiling fan. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     A ceiling fan according to a first invention includes a coupling portion having an upper part supported on a ceiling; a rotary driving portion having a stator fixed to a lower part of the coupling portion and a rotor to be rotary driven around the stator; a plurality of blades to be rotated around a center of the rotor by the rotary driving portion; a support portion which is fixed to the rotor and to which root portions of the blades are attached in a mounting state; and a fall preventing member having a loop portion formed by a wire rod so as to be engageable with the blades and the support portion, and, in the ceiling fan, a through hole that the loop portion of the fall preventing member penetrates is provided in the root portions of the blades, the support portion is provided with an engaging portion which is engageable with the loop portion of the fall preventing member, and the loop portion of the fall preventing member is disposed to be engageable with the engaging portion of the support portion in a state that the blades are attached to the support portion, the loop portion is engaged with the engaging portion of the support portion when an attachment part of the support portion and the blades is broken, and the blades are held on the support portion through the loop portion of the fall preventing member in a state that inner edges of the root portions of the blades are positioned on an outside of an outer edge of the support portion. 
     According to a second invention, in the ceiling fan according to the first invention, a protruded portion is formed as the engaging portion on the support portion, and the root portion of the blade is provided with an opening groove which is extended in a length direction of the blade and is opened at the inner edge of the root portion, and is slidably engaged with the protruded portion, and in a state that the blade is attached to the support portion, the protruded portion of the support portion is engaged with the opening groove of the root portion of the blade, and the loop portion of the fall preventing member is disposed around the protruded portion. 
     According to a third invention, in the ceiling fan according to the first or second invention, the blade is attached to the support portion by a fastening member through a fastening hole provided on the root portion of the blade, and the fastening hole is provided separately from a through hole that the loop portion of the fall preventing member penetrates. 
     According to a fourth invention, in the ceiling fan according to any of the first to third inventions, the through hole of the root portion of the blade is disposed in a shifted position from a center in a width direction of the blade. 
     According to a fifth invention, in the ceiling fan according to any of the first to fourth inventions, the through hole of the root portion of the blade is a slot extended in a length direction of the blade, and the loop portion of the fall preventing member penetrates an opening portion at an outside in the length direction of the blade in the slot in a state that the blade is attached to the support portion. 
     According to a sixth invention, in the ceiling fan according to any of the first to fifth inventions, the loop portion of the fall preventing member includes a discontinuous part of a wire rod and the fall preventing member has a clip function for fixing the loop portion to the blade releasably with front and back faces of the blade interposed by elastic deformation of the loop portion in a thickness direction of the blade. 
     According to a seventh invention, in the ceiling fan according to the sixth invention, the inner edge of the root portion of the blade is provided with a notch portion where one of ends of the wire rod of the fall preventing member is inserted and engaged. 
     According to an eighth invention, in the ceiling fan according to the seventh invention, the blade is provided with a plurality of groove extending in the length direction of the blade on a back face of the blade, and the one of ends of the wire rod of the fall preventing member which is inserted in the notch portion of the inner edge of the root portion of the blade is disposed in the groove of the blade and engaged with the groove of the blade. 
     According to a ninth invention, in the ceiling fan according to any of the first to eighth inventions, the fall preventing member includes a first loop portion penetrating the through hole of the root portion of the blade and a second loop portion which is engageable with the engaging portion of the support portion, and the first loop portion and the second loop portion are formed continuously by a single wire rod. 
     Embodiments according to the present invention will be described below with reference to the drawings. The present invention is not restricted to the embodiments. 
     First Embodiment 
       FIG. 1  is a side view showing a ceiling fan  1  according to a first embodiment of the present invention and  FIG. 2  is a partial enlarged view showing the ceiling fan  1 . 
     As shown in  FIGS. 1 and 2 , the ceiling fan  1  includes a suspending portion  2  fixed to a ceiling  50  and a body portion  3  supported in engagement with the suspending portion  2 . The body portion  3  includes a coupling portion  4 , a rotary driving portion  7 , a support portion  10 , a plurality of blades  11 , and a body cover  22 . 
     The coupling portion  4  includes a joint  5  to be engaged with the suspending portion  2  and a pipe  6  fixed to a lower part of the joint  5 . The joint  5  is suspended in engagement with the suspending portion  2  fixed to the ceiling  50 . Consequently, the coupling portion  4  is supported on the ceiling  50  through the suspending portion  2 . It is possible to employ a structure in which the ceiling fan  1  does not include the suspending portion  2  and the coupling portion  4  is supported by direct suspension from the ceiling  50 . 
     The rotary driving portion  7  is supported on the coupling portion  4 . The rotary driving portion  7  includes a stator  8  taking a shape of an almost circular plate which is fixed to a lower part of the pipe  6  and an almost annular rotor  9  to be rotated around the stator  8 . The rotary driving portion  7  is conducted so that the rotor  9  is rotated around the stator  8 . The support portion  10  is fixed to a peripheral edge of the rotor  9  and is rotated integrally with the rotor  9 . A body cover  22  is attached to cover a lower part of the rotary driving portion  7 . 
     The blades  11  are removably attached to the support portion  10 . As shown in  FIG. 2 , the support portion  10  includes a receiving portion  25  to be a flat plate member taking an annular shape, and a fixing portion  23  for supporting the receiving portion  25  from a lower side. A root portion of the blade  11  is placed on the receiving portion  25 , and the respective blades  11  are removably fixed to the receiving portion  25  and the fixing portion  23  with a screw to be a fastening member as will be described below. 
       FIG. 3  is a partial enlarged view showing an attachment part of the blade  11  to the support portion  10  in the ceiling fan  1 . As shown in  FIG. 3 , the blade  11  includes a root portion  12  mounted (placed) on the receiving portion  25  of the support portion  10 , a vane portion  13  to be a part positioned on an outside in a radial direction from the root portion  12  and serving to substantially send air, and a step portion  14  positioned between the root portion  12  and the vane portion  13 . The blade portion  11  is formed as a metal plate integrally with the root portion  12 , the vane portion  13 , and the step portion  14 , for example. A step height in a width direction of the blade  11  is set to the step portion  14  in such a manner that the vane portion  13  is disposed with inclination at a suitable angle for blast with respect to the root portion  12  provided in an almost horizontal state. Specifically, the vane portion  13  is disposed with inclination with respect to a rotating direction in such a manner that an edge on a rear side in the rotating direction of the blade  11  is lower than an edge on a forward side in the width direction. In order to increase rigidity, moreover, a plurality of ridges and grooves (convex portions and concave portions) extended in a longitudinal direction is provided on the blade  11 . 
     As shown in  FIG. 3 , two fastening holes  24  are provided in the vicinity of both ends in the width direction in the root portion  12  of the blade  11 . A plurality of holes  26  is provided on the receiving portion  25  of the support portion  10 . A fastening member (not shown) such as a screw is inserted into the fastening holes  24  of the root portion  12  of the blade  11  and the holes  26  of the receiving portion  25  to carry out fastening to the fixing portion  23 . Consequently, the root portion  12  of the blade  11  is attached to the support portion  10  in a mounting state. 
     Next, description will be given to a structure for preventing fall of the blade  11  in the case in which the attachment part (the root portion  12  or the like) of the blade  11  in the ceiling fan  1  is broken. 
     As shown in  FIG. 3 , an opening groove  31  is provided on a central part in the width direction in the root portion  12  of the blade  11 . The opening groove  31  is extended in a length direction of the blade  11  and is opened on an inner edge  12   a  of the root portion  12 . The opening groove  31  includes a first hole  31   a  to be an almost square hole which is opened on the inner edge  12   a  of the root portion  12  and a second hole  31   b  to be an almost square hole communicating with the first hole  31   a  and having a greater opening width than the first hole  31   a . The first hole  31   a  is positioned on the inner edge  12   a  side of the root portion  12  from the second hole  31   b.    
     A protruded portion  32   a  protruded upward is provided in the vicinity of an outer peripheral edge  25   a  of the receiving portion  25  of the support portion  10  (an outer edge of the support portion  10 ). The protruded portion  32  is a plate-shaped protruded portion taking a T shape seen from the length direction (a radial direction) of the blade  11 . The protruded portion  32  includes a first flat plate portion  32   a  taking a shape of an almost square plate fixed to the receiving portion  25  and a second flat plate portion  32   b  taking a shape of an almost square plate fixed to an upper part of the first flat plate portion  32   a  and having a greater width than the first flat plate portion  32   a  in the width direction of the blade  11 . 
     Description will be given to the relationship between the opening groove  31  provided on the root portion  12  of the blade  11  and the protruded portion  32  provided on the receiving portion  25 . A width of the second flat plate portion  32   b  of the protruded portion  32  is smaller than an opening width of the second hole  31   b  of the opening groove  31  and is greater than an opening width of the first hole  31   a . A width of the first flat plate portion  32   a  of the protruded portion  32  is smaller than the opening width of the first hole  31   a  of the opening groove  31 . 
     Consequently, the root portion  12  of the blade  11  is mounted on the receiving portion  25  of the support portion  10  so that the protruded portion  32  is inserted into the second hole  31   b  of the opening groove  31 . Then, the blade  11  is moved by a predetermined amount outward in the radial direction so that the first flat plate portion  32   a  of the protruded portion  32  is slid into the first hole  31   a  of the opening groove  31 . As a result, the second flat plate portion  32   b  of the protruded portion  32  and the first hole  31   a  of the opening groove  31  are brought into an engaging state in at least width and thickness directions of the blade  11  as shown in  FIG. 3 . In this state, the two fastening holes  24  of the root portion  12  of the blade  11  are positioned on the two holes  26  of the receiving portion  25  so that a fastening member (not shown) such as a screw can be inserted therein. 
     As shown in  FIG. 3 , a through hole  33  is provided on the root portion  12  of the blade  11  separately from the two fastening holes  24  and the opening groove  31 . The through hole  33  is formed between one of the fastening holes  24  and the opening groove  31  and is formed as a slot extended in the length direction of the blade  11 , and furthermore, is disposed in a position shifted from a center in the width direction of the blade  11 . The fall preventing member  34  penetrates the through hole  33 , and a loop portion of the fall preventing member  34  penetrates an opening part of the slot shape at an outer side in the length direction of the blade  11 . 
       FIG. 4  is a perspective view showing the fall preventing member  34 . As shown in  FIGS. 3 and 4 , the fall preventing member  34  has a loop portion formed by a wire rod and a metal wire rod having rigidity is used for the wire rod, for example. The fall preventing member  34  has a first loop portion  35  and a second loop portion  36 , and the first loop portion  35  is formed as a larger loop portion than the second loop portion  36 . For example, the first loop portion  35  is formed to be a single loop and the second loop portion  36  is formed to be a double loop. Each of the loop portions  35  and  36  is formed continuously by bending a single wire rod. For this reason, the first loop portion  35  and the second loop portion  36  include discontinuous parts of the wire rod (for example, parts in which wire rods are caused to be close to each other so that a loop shape is substantially obtained) respectively. By applying external force to elastically deform the wire rod, for example, it is possible to enlarge the discontinuous part, thereby opening the loop portion. 
     The fall preventing member  34  having the structure is attached to the root portion  12  of the blade  11  as shown in  FIG. 3 . Specifically, the wire rod configuring the first loop portion  35  penetrates the through hole  33  of the root portion  12  of the blade  11 . The second loop portion  36  is disposed so as to surround the second hole  31   b  of the opening groove  31 . Furthermore, one of ends of the wire rod in the fall preventing member  34  is inserted in and engaged with a notch portion  38  provided on the inner edge  12   a  of the root portion  12  of the blade  11 . As described above, the fall preventing member  34  includes discontinuous parts of the wire rod. Each of the wire rods configuring the first and second loop portions  35  and  36  is elastically deformed in the thickness direction of the blade  11  to enlarge the discontinuous part and is thus caused to penetrate the through hole  33 , and furthermore, one of ends of the wire rod is inserted in the notch portion  38 . Consequently, the wire rod configuring the fall preventing member  34  can be releasably fixed to the blade  11  with front and back faces of the blade  11  interposed. In other words, the fall preventing member  34  has a clip function for interposing and fixing the front and back faces of the blade  11  while performing the elastic deformation. 
     In a state in which the root portion  12  of the blade  11  to which the fall preventing member  34  is fixed is mounted on the receiving portion  25  and is attached with a fastening member (not shown) such as a screw as shown in  FIG. 3 , moreover, the protruded portion  32  of the receiving portion  25  is engaged with the opening groove  31  of the blade  11 . The second loop portion  36  of the fall preventing member  34  is disposed around the protruded portion  32  in this state. 
     Description will be given to an operation of the ceiling fan  1  according to the first embodiment having such a structure. In the ceiling fan  1 , when the rotary driving portion  7  is conducted, the rotor  9  is rotated. The blade  11  fixed to the support portion  10  is rotated around a center of the rotor  9  together with the support portion  10  by the rotation. In the blade  11 , the vane portion  13  is gradually inclined obliquely and downward from a forward side toward a rear side in a rotating direction by the step portion  14 . Therefore, air flowing along a lower surface of the vane portion  13  is sent from the ceiling  50  side in a floor direction (downward). The respective blades  11  are rotary driven at a rotating speed of approximately 200 to 300 rotations/minute, for example. 
     Description will be given to a function and operation for preventing fall of the blade  11  by the fall preventing member  34  in the case in which the attachment part of the blade  11  to the support portion  10  is broken, for example, the root portion  12  of the blade  11  is broken in the ceiling fan  1  according to the first embodiment. 
     In the case in which the attachment part of the blade  11  and the support portion  10  is broken during the operation of the ceiling fan  1 , the root portion  12  of the blade  11  tries to be separated by centrifugal force in an outer direction (outward in a radial direction) from the receiving portion  25  of the support portion  10 . When the blade  11  starts movement outward in the radial direction, the opening groove  31  engaged with the protruded portion  32  is slid with respect to the protruded portion  32  of the receiving portion  25 . Consequently, the second loop portion  36  of the fall preventing member  34  disposed around the protruded portion  32  comes in contact with the protruded portion  32  and the sliding movement further proceeds so that the second loop portion  36  is engaged with the protruded portion  32  (is brought into a catching state). 
     In addition, the blade  11  is separated from the support portion  10  outward in the radial direction so that the respective loop portions  35  and  36  of the fall preventing member  34  are deformed, and furthermore, the protruded portion  32  is separated by the opening groove  31  of the root portion  12  of the blade  11  (the opening groove  31  and the protruded portion  32  are disengaged from each other). The blade  11  is further separated by the centrifugal force and the inner edge  12   a  of the root portion  12  of the blade  11  is positioned on an outside in the radial direction from the outer edge  25   a  of the support portion  10  (see  FIG. 5 ). On the other hand, the centrifugal force of the blade  11  or the like is applied to the fall preventing member  34  to cause large deformation. However, the fall preventing member  34  penetrates the through hole  33  in the first loop portion  35  and the second loop portion  36  is engaged with the protruded portion  32 . Consequently, the blade  11  is held in the support portion  10  through the loop portions  35  and  36  of the fall preventing member  34  so that the fall of the blade  11  can be prevented. 
     When the operation of the ceiling fan  1  is continuously carried out in this state, the blade  11  in the holding state on the support portion  10  through the fall preventing member  34  tries to hold a posture in a horizontal state by the centrifugal force generated by the rotation as shown in  FIG. 6 . However, the inner edge  12   a  of the root portion  12  of the blade  11  is positioned on the outside of the outer edge  25   a  of the support portion  10 . For this reason, the rotating posture of the blade  11  is brought into an unstable state. For example, a forward side end in the rotating direction of the blade  11  is inclined to be lowered greatly from a rear side end so that high resistance is applied to the vane portion  13  of the rotated blade  11  and the behavior of the blade  11  is brought into an unstable state. Therefore, even if the operation of the ceiling fan  1  is continuously carried out, a user can clearly recognize the unstable behavior of the blade  11  and can grasp that breakage or the like is caused on the blade  11 . 
     Moreover, the through hole  33  through which the wire rod of the fall preventing member  34  penetrates is provided in the position shifted from the center in the width direction of the root portion  12  of the blade  11 . Consequently, it is possible to reliably cause an inclination posture to be taken in the blade  11  held by the fall preventing member  34 . 
     In a state in which the operation of the ceiling fan  1  is stopped, moreover, the inner edge  12   a  of the root portion  12  of the blade  11  is positioned on the outside of the outer edge  25   a  of the support portion  10  as shown in  FIG. 7 . Consequently, the edge on the outside in the radial direction of the blade  11  is suspended greatly so that an almost vertical posture can be taken. In the state in which the operation of the ceiling fan  1  is stopped, therefore, a user can clearly recognize the almost vertical posture of the blade  11  and can grasps that the breakage or the like is caused on the blade  11 . 
     Furthermore, the through hole  33  is caused to take a shape of a slot extended in a length direction of the blade  11 . Consequently, it is possible to hold the blade  11  by the fall preventing member  34  by ensuring such a separation distance (stroke) as to enable the inner edge  12   a  of the blade  11  to be positioned on the outside of the outer edge  25   a  of the support portion  10 . 
     In a state in which the fall preventing member  34  is attached to the blade  11 , furthermore, the second loop portion  36  is disposed around the second hole  31   b  of the opening groove  31 . Consequently, when the blade  11  is to be attached to the support portion  10 , it is possible to bring a state in which the second loop portion  36  is disposed around the protruded portion  32  by simply inserting the protruded portion  32  of the receiving portion  25  into the second hole  31   b  of the opening groove  31  of the blade  11 . By carrying out normal works for attaching the blade  11 , therefore, it is possible to bring a state in which the fall preventing member  34  can be engaged with the engaging portion (the protruded portion  32 ) of the support portion  10 . Thus, workability can be enhanced, and furthermore, it is possible to prevent engagement from being forgotten. 
     The opening groove  31  to be engaged with the protruded portion  32  is caused to take an opening shape in the inner edge  12   a  of the root portion  12  of the blade  11 . In the case in which the breakage or the like is caused on the blade  11 , consequently, the opening groove  31  is slid along the protruded portion  32  and the protruded portion  32  and the opening groove  31  are then disengaged from each other. Thus, the inner edge  12   a  of the blade  11  can be positioned on the outer side than the outer edge  25   a  of the support portion  10 . 
     Moreover, the fall preventing member  34  includes the loop portions  35  and  36  formed by the wire rods and has such a clip function as to be fixed with the surface and the back face of the blade  11  interposed by the elastic deformation of the wire rods. Consequently, it is possible to attach the fall preventing member  34  to the blade  11  without using another member. For example, the fall preventing member  34  is attached in a proper position for the blade  11  at the time of factory shipment. When the ceiling fan  1  is to be assembled, consequently, it is possible to carry out an assembling work without paying attention to the fall preventing member  34 . Accordingly, it is possible to prevent the attachment of the fall preventing member  34  from being forgotten. 
     Second Embodiment 
     Next, a ceiling fan according to a second embodiment of the present invention will be described. Referring to the ceiling fan according to the second embodiment, a configuration of a fall preventing member formed by a wire rod is different from that of the fall preventing member  34  according to the first embodiment. A difference between the configurations of the fall preventing members will be mainly described. In the ceiling fan according to the second embodiment, the same components as those of the ceiling fan  1  according to the first embodiment have the same reference numerals and description thereof will be omitted. 
       FIG. 8  is a partial enlarged view showing an attachment part of a blade  11  to a support portion  10  in a ceiling fan  51  according to the second embodiment. Moreover,  FIG. 9  is a view showing an external appearance of a fall preventing member  52 . 
     As shown in  FIGS. 8 and 9 , a diameter of a wire rod for forming the fall preventing member  52  is increased so that a loop portion is deformed with difficulty in the ceiling fan  51  according to the second embodiment. The fall preventing member  52  is formed by bending a single wire rod so as to have a first loop portion  53  and a second loop portion  54 . The first and second loop portions  53  and  54  are formed into a single loop. 
     The first loop portion  53  takes a shape of a long loop in a length direction of the blade  11  and a bent portion (curved portion)  53   a  obtained by curving a wire rod is provided on an end at a radial outside of the blade  11  in a longitudinal direction thereof. 
     The second loop portion  54  takes a shape of an almost triangular loop and a base portion  54   a  of the almost triangular shape is disposed in a width direction of the blade  11 , and furthermore, a top portion  54   b  opposed to the base portion is provided toward an inner edge  12   a  side of a root portion  12  of the blade  11 . In the second loop portion  54 , an opening width in the width direction of the blade  11  (a width of a loop portion surrounded by a wire rod) is gradually reduced closer to the top portion  54   b . Moreover, the top portion  54   b  of the second loop portion  54  serves as a bent portion (curved portion)  54   b  obtained by curving a wire rod. 
     A notch portion  55  is provided on the inner edge  12   a  of the root portion  12  of the blade  11 , and one of ends of the wire rod of the fall preventing member  52  is inserted in and engaged with the notch portion  55 . In the root portion  12  of the blade  11 , a through hole  33  and the notch portion  55  are disposed with an opening groove  31  interposed therebetween. For this reason, in a state in which the fall preventing member  52  is attached to the blade  11 , a back face side (a lower face side) of the blade  11  and a wire rod are engaged in contact with each other in the through hole  33  and the notch portion  55 . In addition, the wire rod of the second loop portion  54  is provided in contact with a front face side (an upper face side) of the blade  11  around a second hole  31   b  of the opening groove  31  positioned between the through hole  33  and the notch portion  55 . Consequently, it is possible to stably attach the fall preventing member  52  to the blade  11  by interposing the front and back faces of the blade  11  (that is, by utilizing a clip function) while elastically deforming the wire rod of the fall preventing member  52 . 
     In a state in which the fall preventing member  52  of the blade  11  is attached as shown in  FIG. 8 , the wire rod of the first loop portion  53  penetrates the through hole  33  and the wire rod penetrates an opening part at a radial outside of a slot shape. Moreover, the second loop portion  54  is disposed around a protruded portion  32  and the second hole  31   b  of the opening groove  31 . Moreover, the protruded portion  32  is positioned in the vicinity of the base portion  54   a  of the almost triangular shape and a distance L1 is maintained between the top portion  54   b  and the protruded portion  32  at an inside of the second loop portion  54 . Moreover, a distance L2 is maintained as an opening length in a longitudinal direction of the through hole  33  through which the first loop portion  53  penetrates. 
     Description will be given to a function and operation for preventing fall of the blade  11  by the fall preventing member  52  in the case in which the attachment part of the blade  11  to the support portion  10  is broken, for example, the root portion  12  of the blade  11  is broken in the ceiling fan  51  according to the second embodiment. 
     In the case in which breakage or the like is caused on the attachment part of the blade  11  and the support portion  10  during the operation of the ceiling fan  51 , the root portion  12  of the blade  11  tries to be separated by centrifugal force in an outer direction (outward in a radial direction) from the receiving portion  25  of the support portion  10 . When the blade  11  starts movement outward in the radial direction, the opening groove  31  engaged with the protruded portion  32  is slid with respect to the protruded portion  32  of the receiving portion  25 . On the other hand, the distance L1 is maintained between the top portion  54   b  and the protruded portion  32  at the inside of the second loop portion  54 . For this reason, the second loop portion  54  of the fall preventing member  52  will come in contact with the protruded portion  32  so that both of them are engaged with each other only after the opening groove  31  is slid by the distance L1 with respect to the protruded portion  32 . At this time, the second loop portion  54  takes an almost triangular shape and has a reduced opening width as gradually closer to the top portion  54   b . Therefore, the protruded portion  32  and the top portion  54   b  of the second loop portion  54  are easily engaged with each other. 
     Furthermore, the blade  11  is separated from the support portion  10  outward in the radial direction. Consequently, a bent portion  53   a  of the first loop portion  53  of the fall preventing member  52  is slid relatively in the longitudinal direction of the through hole  33  taking a shape of a slot. When the sliding movement is carried out by the distance L2, the bent portion  53   a  of the first loop portion  53  comes in contact with the end on the inside in the radial direction of the blade  11  in the through hole  33 . In this state, the inner edge  12   a  of the root portion  12  of the blade  11  is positioned on an outside in the radial direction from the outer edge  25   a  of the support portion  10  (see  FIG. 10 ). In this state, the first loop portion  53  penetrates the through hole  33  and the second loop portion  54  is engaged with the protruded portion  32 . Consequently, the blade  11  is held in the support portion  10  through the loop portions  53  and  54  of the fall preventing member  52  so that the fall of the blade  11  can be prevented. 
     In the fall preventing member  52  according to the second embodiment, a diameter of the wire rod is increased so that the loop portion is deformed with difficulty. However, the distance L1 is maintained between the top portion  54   b  of the second loop portion  54  and the protruded portion  32 , and the distance L2 is maintained as the opening length in the longitudinal direction of the through hole  33  through which the first loop portion  53  penetrates. A total distance of the distance L1 and the distance L2 serves as a stroke in which the blade  11  is moved to the outside in the radial direction. Thus, the stroke (that is, L1+L2) is set. Even if the wire rod of the fall preventing member  52  is not deformed, consequently, the inner edge  12   a  of the root portion  12  of the blade  11  can be positioned on the outside of the outer edge  25   a  of the support portion  10 . 
     In the fall preventing member  52 , a bent portion  53   a  is provided on the first loop portion  53  and the inner edge  12   a  of the through hole  33  is caused to come in contact with the wire rod in the bent portion  53   a . Consequently, it is possible to suppress stress concentration on the wire rod. Moreover, the top portion  54   b  of the second loop portion  54  serves as the bent portion to come in contact with the protruded portion  32 . Consequently, it is possible to suppress the stress concentration on the wire rod. 
     The ceiling fan  51  according to the second embodiment is the same as the ceiling fan  1  according to the first embodiment in that a user can clearly recognize a breakage of the blade in the event of the breakage at an operation time and a stop time. By using the fall preventing member  52  according to the second embodiment, it is possible to reliably hold the blade  11  with use of the fall preventing member  52  having higher rigidity in the event of the breakage of the blade  11 . 
     Third Embodiment 
     Next, a ceiling fan according to a third embodiment of the present invention will be described. Referring to the ceiling fan according to the third embodiment, a configuration of a fall preventing member formed by a wire rod is different from that of the fall preventing members  34 ,  52  according to the first and second embodiments. A difference between the configurations of the fall preventing members will be mainly described. In the ceiling fan according to the third embodiment, the same components as those of the ceiling fans  1 ,  51  according to the first and second embodiments have the same reference numerals and description thereof will be omitted. 
       FIG. 11  is a partial enlarged view showing an attachment part of a blade  11  to the support portion  10  in a ceiling fan  61  according to the third embodiment. Moreover,  FIG. 12  is a view showing an external appearance of a fall preventing member  62  in an attached state to the blade  11 , and  FIG. 13  is a view showing an external appearance of the fall preventing member  62 . 
     As shown in  FIGS. 11 through 13 , a diameter of a wire rod for forming the fall preventing member  62  is increased so that a loop portion is deformed with difficulty in the ceiling fan  61  according to the third embodiment in the same manner as the fall preventing member  52  of the second embodiment. The fall preventing member  62  is formed by bending a single wire rod so as to have a first loop portion  63  and a second loop portion  64 . The first and second loop portions  63  and  64  are formed into a single loop. The second loop portion  64  has the same configuration as the second loop portion  54  of the fall preventing member  52  of the second embodiment. 
     As shown in  FIG. 13 , the first loop portion  63  takes a shape of a long loop in a length direction of the blade  11  and a bent portion (curved portion)  63   a  obtained by curving a wire rod is provided on an end at a radial outside of the blade  11  in a longitudinal direction thereof. A bent portion  63   b  is provided on an inside end in the radial direction of the blade  11  in the loop shape of the first loop portion  63 . The bent portion  63   b  is obtained by curving the wire rod toward a direction approximately intersecting with the radial direction (for example, the wide direction of the blade). Further, the wire rod is extending from the bent portion  63   b  to a position across the second loop portion  64  in the wide direction of the blade  11 , and at the position, a bent portion  63   c  obtained by curving the wire rod toward the outside end in the radial direction of the blade  11 . The end of the wire rod toward the outside end in the radial direction of the blade  11  from the bent portion  63   c  is an engaging portion  63   d  engaging the wire rod with the blade  11 . 
     The engaging portion  63   d  which is one of ends of the wire rod of the fall preventing member  62  is inserted in and engaged with the notch portion  55  provided on the inner edge  12   a  of the root portion  12  of the blade  11 . The engaging portion  63   d  is inserted in the notch portion  55  by inserting while elastically deforming the engaging portion  63   d  which is a linear part of the wire rod so as to bring the engaging portion  63   d  close to the second loop portion  64  in the wide direction of the blade  11 . 
     The blade  11  is provided with a plurality of groove  11   a  (convex portions in the upper view and concave portions in the lower view) extending in the length direction of the blade  11  on a back face of the blade  11 . The notch portion  55  is formed along the groove  11   a  extended in the longitudinal direction of the blade  11 . Therefore, the engaging portion  63   d  is inserted in the notch portion  55  from the front face side to the back face side of the blade  11  so that the engaging portion  63   d  is disposed in the groove  11   a  and engaged with an inner surface of the groove  11   a.    
     The through hole  33  having the slot shape is formed along another groove  11   a  extended in the longitudinal direction of the blade  11 . Therefore, the liner part of the wire rod (between the bent portions  63   a  and  63   b ) inserted in the through hole  33  is disposed in the groove  11   a  and engaged with an inner surface of the groove  11   a.    
     The engaging portion engaging with the blade  11  in the fall preventing member  62  is disposed in and along the groove  11   a  formed in the blade  11  thereby enhancing the clip function by utilizing the elasticity of the blade  11 . In addition, it is possible to suppress positional shift of the fall preventing member  62  in the wide direction of the blade  11  thereby enhancing a positional accuracy of the fall preventing member  62 . 
     As shown in  FIGS. 11 and 12 , a seal tape  65  is attached on the front face of the blade  11  so as to extend in the wide direction of the blade  11 . One end of the seal tape  65  is attached to the wire rod of the second loop portion  64  of the fall preventing member  62 . Thereby, it is possible to prevent positional shift of the fall preventing member  62  in the longitudinal direction of the blade  11 . The seal tape  65  is attached along the front face having a plurality of convex and concave portions of the grooves  11   a , thereby it is possible to prevent peeling off the seal tape  65 . On the other hand, an external force is applied to the fall preventing member  62  so as to move the fall preventing member  62  in the longitudinal direction of the blade  11 , this movement of the fall preventing member leads to break the seal tape  65 . Accordingly, it is possible to make a judgment on whether the fall preventing member  62  is attached in the proper position by confirming whether the seal tape  65  does not have a break. 
     The ceiling fan  61  according to the third embodiment is the same as the ceiling fan  51  according to the second embodiment in that the ceiling fan  61  has a function and operation for preventing fall of the blade  11  by the fall preventing member  62  in the case in which the attachment part of the blade  11  to the support portion  10  is broken, for example, the root portion  12  of the blade  11  is broken in the ceiling fan  61  (refer to  FIG. 14 ). Accordingly, a user can clearly recognize a breakage of the blade in the event of the breakage at an operation time and a stop time. By using the fall preventing member  62  according to the third embodiment, it is possible to attach the fall preventing member  62  to the blade  11  with enhancing a positional accuracy thereof. Furthermore, it is possible to enhance a clip function of the fall preventing member  62  thereby making it easy to attach the fall preventing member  62  to the blade  11 . 
     In the description of the embodiments, there is taken, as an example, the case in which the second loop portion  36  of the fall preventing member  34  is engaged with the protruded portion  32  protruded in the vicinity of the outer edge  25   a  of the receiving portion  25  in the support portion  10 . However, the configuration of the protruded portion  32  is not restricted to only this case. In the support portion  10 , it is preferable to provide an engaging portion with which the second loop portion  36  can be engaged. It is possible to employ various structures other than the protruded portion  32  as the configuration of the engaging portion. 
     Moreover, as an example, the case was described in which the through hole  33  through which the wire rod of the fall preventing member  34  penetrates is disposed with a shift (that is, eccentricity) from the center in the width direction of the blade  11  in the root portion  12  of the blade  11 . However, the formation position of the through hole is not restricted to only this configuration. For example, it is possible to employ the case in which the through hole is disposed on the center in the width direction of the blade  11 . In this case, when the blade  11  is broken, it is possible to bring the behavior of the blade  11  into an unstable state to some degree by positioning the inner edge  12   a  of the root portion  12  of the blade  11  at the outside of the outer edge  25   a  of the support portion  10 . 
     Although as an example, the case was described in which the fall preventing member has two loop portions, that is, the first loop portion and the second loop portion, furthermore, it is possible to employ the case in which only one loop portion is provided. 
     By properly combining optional ones of the various embodiments, it is possible to produce the respective advantages. 
     Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. 
     EXPLANATION OF REFERENCE NUMERALS 
     
         
         
           
               1  ceiling fan 
               2  suspending portion 
               3  body portion 
               4  coupling portion 
               5  joint 
               6  pipe 
               7  rotary driving portion 
               8  stator 
               9  rotor 
               10  support portion 
               11  blade 
               12  root portion 
               12   a  inner edge 
               13  vane portion 
               14  step portion 
               22  body cover 
               23  fixing portion 
               24  fastening hole 
               25  receiving portion 
               25   a  outer edge (outer peripheral edge) 
               26  hole (hole of receiving portion  25 ) 
               31  opening groove 
               31   a  first hole 
               31   b  second hole 
               32  protruded portion 
               32   a  first flat plate portion 
               32   b  second flat plate portion 
               33  through hole 
               34  fall preventing member 
               35  first loop portion 
               36  second loop portion 
               38  notch portion 
               50  ceiling 
               51  ceiling fan 
               52  fall preventing member 
               53  first loop portion 
               53   a  bent portion 
               54  second loop portion 
               54   a  base portion 
               54   b  top portion (bent portion) 
               55  notch portion 
               61  ceiling fan 
               62  fall preventing member