Abstract:
A ceiling fan with oscillating mechanism includes a clutch member for adjusting the angle of oscillation according to user&#39;s need. When the motor is actuated, the rotating torque induced by the motor and the transmission mechanism is smaller than the rotational resistance of the clutch member such that the motor may drive the fan to oscillate. Further, when the user applies an external rotational force greater than the rotational resistance of the clutch member, the user can swing the fan to any angle as desired without rotating or shifting other members except the fan and the fan suspension tube. In this manner, undesired damage of the mechanism or motor due to inappropriately applied external force can be avoided efficiently.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Taiwanese Patent Application No. 101209324 filed on May 17, 2012, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated by reference herein. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a fan oscillating mechanism and a ceiling fan using the same, and more particularly to a fan oscillating mechanism which is adaptable to conventional electric fan and enables the airflow direction of the fan to be adjusted as desired. 
         [0004]    2. Description of Related Art 
         [0005]    In the conventional oscillating mechanism of an electric fan, the speed reduction mechanism is driven by the motor of fan blade, and is connected to one end of a connecting rod, while the other end of the connecting rod is connected to the fan casing or base. In this way, the conventional oscillating mechanism of electric fan is driven indirectly by the fan motor to oscillate. 
         [0006]    Please refer to  FIG. 1  which schematically shows the conventional oscillating mechanism of electric fan. As shown in the figure, a worm gear  111  meshed with a worm wheel  12  is disposed at the tail end of a primary driving shaft  11  of the fan. A reduction gear unit formed by two gears  13 ,  14  is operatively coupled to the lower end of the worm wheel  12 . The gear  14  has a shaft  15  connected pivotally to one end of a crank plate  16 . The other end of the crank plate  16  is connected pivotally to one end of a connecting rod  17 . The other end of the connecting rod  17  is connected pivotally to a driving element  171  received in a slot  181  of the casing  18 . 
         [0007]    The operation of the afore-mentioned conventional oscillating mechanism will be described as follow. Firstly, the fan rotates and the primary driving shaft  11  of the fan drives the speed reduction mechanism formed by the worm gear  111 , the worm wheel  12 , and the gears  13 ,  14  of the reduction gear unit. Then, the shaft  15  of the gear  14  moves the crank plate  16  which in turn moves the connecting rod  17 . Finally, the driving element  171  moves the casing  18  to oscillate. 
         [0008]    However, the oscillation angle of the conventional oscillating mechanism cannot be adjusted. If an external force is imposed to vary the oscillation angle of oscillation, potential risks such as the collapse of the gear tooth, fracture of the connecting rod or driving elements might occur. 
       SUMMARY OF THE INVENTION 
       [0009]    The primary object of the present invention is to provide a fan oscillating mechanism and a ceiling fan using the same, which make use of a clutch member for adjusting the oscillation angle of the fan according to users&#39; need, so that undesired damage of the interior mechanisms or motor due to inappropriate rotation can be avoided. 
         [0010]    In order to achieve the above and other objects, the fan oscillating mechanism according to a preferred embodiment of the present invention comprises a motor transmission mechanism, a spindle link, a fan suspension tube, and a clutch member. The motor transmission mechanism includes a motor having a driving shaft, a crank plate having one end connected pivotally to the driving shaft, and a connecting rod having a first end connected pivotally to the other end of the crank plate, and a second end. The spindle link includes a head end connected pivotally to the second end of the connecting rod, and a tail end. The fan suspension tube includes a top end connected to the tail end of the spindle link and a bottom end connected to a fan device. The clutch member includes a wave washer disposed between the spindle link and the fan suspension tube to provide rotational resistance. Furthermore, the clutch member can be formed by clutch lining, dampers or electromagnetic clutch device to achieve its clutch function. 
         [0011]    When the motor is actuated, the driving shaft rotates the crank plate to move the connecting rod so as to rotate the spindle link. As the rotating torque induced by the spindle link is smaller than the rotational resistance of the clutch member, the spindle link may move the fan suspension tube. This is the normal operating state in which the oscillation of the fan is actuated by the motor. On the other hand, when the fan suspension tube is subjected to an external rotational force which is greater than the rotational resistance of the clutch member, the fan suspension tube runs free. In other words, when a user applies an external rotational force which is greater than the rotational resistance of the clutch member, the oscillation angle can be changed as desired, while the other members except the fan suspension tube will not rotate or shift following this change so that undesired damage of the mechanism or motor due to inappropriately applied external force can be precluded efficiently. Further, as the motor is designed not to make reverse rotation and can operate continuously, the service life of the motor is prolonged. 
         [0012]    Preferably, the clutch member of the present invention may comprises two wave washers and two flat washers with the two wave washers disposed between the two flat washers, and the clutch member is fitted on the outside of the spindle link. In this manner, the clutch member of the present invention which is formed of two wave washers and two flat washers is simple in construction and low in cost. Further, the rotational resistance of the clutch member can be adjusted as desired by simply changing the quantity or the specification of the wave washer and the flat washer. 
         [0013]    Furthermore, the second end of the connecting rod in the present invention has an oval shape slot, and the end face of the head end of the spindle link is provided with an axially extending raised post at one side thereof. The raised post is fitted with a sleeve thereon and received in the oval shape slot along with the sleeve in such a manner that the sleeve is rotatable with respect to the raised post. In this way, as the connecting rod of the present invention has an oval shape slot to provide spaces for rotation and displacement during operation and also owing to the assistance of the sleeve, the connecting rod and the spindle link can have smooth operation without interference occurred therebetween so that the service life can be significantly extended. Moreover, the oval shape slot requires lesser labor force and material than its conventional circular counterpart, and provides an extended permissible tolerance range. Therefore, damage due to assembly error is avoided. However, as compared with a circular slot, the oval shape slot may cause the oscillation of the fan device to lag behind by a few seconds, and the fan device is prone to vibrate. 
         [0014]    Therefore, the present invention may adopt the oval shape slot or circular slot in the preferred embodiment. However, the present invention is not limited to the oval or circular slot. Slots having other shapes such as rectangular shape, curved shape, polygonal shape and the like can also be adapted in the present invention. 
         [0015]    Further, a transverse cut-out is provided at one side of the head end of the spindle link, which is provided to prevent interference between the elements during operation and effectively reduce the volume occupied by the entire elements. Likewise, the design of the cut-out of the present invention can save material, reduce labor cost, extend the tolerance range so that damage caused by assembly error is reduced. 
         [0016]    Moreover, the present invention comprises two wave washers, two flat washers and a fixing device. The first end of the connecting rod is held between the two wave washers and then the two flat washers are respectively disposed on the upper side and the lower side of the two wave washers. The fixing device is to maintain the connecting rod being held between the two wave washers. The fixing device can be a locking screw which penetrates through the two wave washers, the two flat washers, and the first end of the connecting rod, and is threaded or fixed to the other end of the crank plate. In this way, the arrangement of the wave washers and the flat washers in the present invention can provide sufficient cushion and connection tolerance between the connecting rod and the crank plate so that the service life of the components is prolonged. Besides, the extension in tolerance range facilitates the assembly of the elements. 
         [0017]    Moreover, the present invention comprises a motor base and a spindle base. The motor can be mounted on the motor base and the spindle base can be fixed to the motor base. The spindle base includes a bearing collar through which the spindle link penetrates and connects to the top end of the fan suspension tube. The spindle base can be a U shaped base, and two limiting screws are screwed onto the surface of the base plate of the spindle base. A stop block extends radially outwards from the end face of the head end of the spindle link and the stop block, and can reciprocate between the two limiting screws along with the rotation of the spindle link. In this way, when the spindle link rotates to move the stop block to urge against one of the two limiting screws, the driving shaft of the motor discontinues its rotation and revolves to cause the fan to revolve and in turn to oscillate in cycle. In this manner, the two limiting screws can be used to limit the oscillation range of the fan. 
         [0018]    Furthermore, the tail end of the spindle link in the present invention has an external thread provided thereon, while the top end of the fan suspension tube has an inner thread provided thereon. The inner thread on the top end of the fan suspension tube is to be engaged with the external thread on the tail end of the spindle link and the clutch member is held therebetween in such a manner that the fan suspension tube and spindle link are not fully fastened with each other so as to achieve free rotation relative to each other. 
         [0019]    Moreover, the fan suspension tube in the present invention has a baffle plate provided on its top end, while one of the two limiting screws is a longer screw which penetrates through the base plate of the spindle base and has an abutting segment protruding downwards. When the fan suspension tube is in an idling state, the abutting segment stops the baffle plate from rotating beyond  360  degrees and breaking the wire. What is more, the fan suspension tube in threading with the spindle link can also be prevented from over-rotation which may result in the loosening and falling off of the suspension tube. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
           [0021]      FIG. 1  is a schematic view showing a conventional fan oscillating mechanism; 
           [0022]      FIG. 2  is an exploded view of an embodiment of the present invention; 
           [0023]      FIG. 3  is a perspective view of an embodiment of the present invention; and 
           [0024]      FIG. 4  is a perspective view of an embodiment of the present invention as viewed from another direction. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0025]    With reference to the accompanying drawings,  FIG. 2  is an exploded view of the fan oscillating mechanism according to a embodiment of the present invention;  FIG. 3  is a perspective view of the fan oscillating mechanism of the present invention; and  FIG. 4  is a perspective view of the fan oscillating mechanism according to the present invention as viewed from another direction. The following embodiments are given using the ceiling fan as an implement example. However, the present invention is not restricted to the ceiling fan, some other fans which include an oscillating mechanism therein such as the desk fan, standing fan or hanging fan are also within the realm of the present invention. 
         [0026]    As shown in the figures, a motor  2  comprises a driving shaft  21  through which the motor output the rotating torque. The motor  2  is fixed on a motor base  22  which can be attached to the wall or the ceiling, depending on the installation site desired. The driving shaft  21  of the motor  2  is connected pivotally to one end of a crank plate  3 , while the other end of the crank plate  3  is connected pivotally to a first end  41  of a connecting rod  4 . In this embodiment, the first end  41  of the connecting rod  4  is held between two wave washers  31 , and two flat washers  32  are respectively disposed on the upper side and lower side of the two respective wave washers  31 . A locking screw  33  is provided to penetrate through the two wave washers  31 , the two flat washers  32 , and the first end  41  of the connecting rod  4 , and is threaded to the other end of the crank plate  3  so that the first end  41  of the connecting rod  4  is pivotally connected with the locking screw  33 . In this way, the arrangement of the wave washers  31  and the flat washers  32  provides sufficient cushion and connection tolerance between the connecting rod  4  and the crank plate  3  so that the service life of the components is prolonged. Besides, the extension of the tolerance range facilitates the convenient assembly. 
         [0027]    Furthermore, a second end  42  of the connecting rod  4  is connected pivotally to a head end  51  of a spindle link  5 . The second end  42  of the connecting rod  4  has a slot  421 . The end face  510  of the head end  51  of the spindle link  5  is provided with an axially extending raised post  511  at one side thereof. The raised post  511  is fitted with a sleeve  422  thereon and placed in the slot  421  along with the sleeve  422  in such a manner that the sleeve  422  is rotatable with respect to the raised post  511 . 
         [0028]    The slot  421  located at the second end  42  of the connecting rod  4  according to the present embodiment can be an oval shape slot. The slot  421  provides spaces for rotation and displacement during operation. Moreover, with the assistance of the sleeve  422 , there is smooth operation between the connecting rod  4  and the spindle link  5  without interference occurred therebetween. Therefore, the service life of the elements is significantly extended. The slot  421  in oval shape requires lesser labor force and material than its conventional circular counterparts. Furthermore, as the tolerance range of the slot is extended, damage due to assembly error is reduced. 
         [0029]    As compared with a circular slot, the oval shape slot may cause the oscillation of the fan device to lag behind by a few seconds, and the fan device is prone to vibrate. To inhibit the vibration of the fan device, the slot  421  located at the second end  42  of the connecting rod  4  could be the conventional circular slot, so as to meet users&#39; different demands. 
         [0030]    At the side of the end face of the head end  51  of the spindle link  5  opposite to the side where the raised post  511  is located, a cut-out  512  is provided. The cut-out  512  serves to reduce the spaces between the elements thus preventing interference between the elements. Specifically, when the motor  2  rotates, the flat washers  32  below the crank plate  3  and the connecting rod  4  will interfere with the head end  51  of the spindle link  5 . The cut-out  512  can effectively avoid such interference from happening. Likewise, the design of the cut-out  512  can save material, reduce labor cost, and extend the tolerance range. Consequently, interference due to assembly error can be avoided. 
         [0031]    As shown in  FIGS. 2 and 3 , a bearing collar  531  is mounted on a spindle base  53  which is fixed on the motor base  2 . The spindle link  5  passes through the bearing collar  531 . A stop block  54  extends radially outwards from the end face  510  of the head end  51  of the spindle link  5 , at a location in proximity to the raised post  511 . In this embodiment, the spindle base  53  is a U shaped base, and two limiting screws  533  are screwed onto the upper surface  532  of the base plate  530 . The stop block  54  provided on the head end  51  of the spindle link  5  reciprocates between the two limiting screws  533  along with the rotation of the spindle link  5 . In this way, when the spindle link  5  rotates to move the stop block  54  to urge against one of the two limiting screws  533 , the driving shaft  21  of the motor  2  revolves to cause the fan to rotate and in turn to oscillate in cycle. That is to say, the two limiting screws  533  are used to limit the rotation range of the spindle link  5 , i.e., the oscillation angle of the fan, which is set to be  110  degrees in this embodiment. 
         [0032]    Further, the spindle link  5  is connected in series with a clutch member  7  and a tail end  52  of the spindle link  5  is connected to a fan suspension tube  6 . In this embodiment, the clutch member  7  includes two wave washers  71  and two flat washers  72 . The two wave washers  71  are disposed between the two flat washers  72 . The clutch member  7  is fitted on the spindle link  5 . In this manner, the clutch member  7  of this embodiment which is formed of two wave washers  71  and two flat washers  72  is simple in construction and low in cost. Besides, the rotational resistance of the clutch member  7  can be adjusted as desired by simply changing the quantity or the specification of the wave washer  71  and the flat washer  72 . 
         [0033]    Referring back to  FIG. 2 , in this embodiment, the tail end  52  of the spindle link  5  has an external thread  520  provided thereon, while the top end  61  of the fan suspension tube  6  has an inner thread  610  provided thereon. The inner thread  610  on the top end  61  of the fan suspension tube  6  is to be engaged with the external thread  520  on the tail end  52  of the spindle link  5 . Moreover, one of the two limiting screws  533  is a longer screw  534  which extends through the base plate  530  of the spindle base  53  and has an abutting segment  535  that protrudes downwards. In addition, a baffle plate  611  is provided on the top end  61  of the fan suspension tube  6 . The baffle plate  611  is designed to be stopped by the abutting segment  535  so as not to rotate beyond 360 degrees. When the fan suspension tube  6  is in a free state, the abutting segment  535  stops the baffle plate  611  from rotating beyond 360 degrees and breaking the wire. Furthermore, the connected fan suspension tube  6  is precluded from over-rotation and subsequently loosening and falling off. As to a tail end  62  of the fan suspension tube  6 , it is connected to a fan device  8 . 
         [0034]    The operation of this embodiment is detailed as follows. As the clutch member  7  is formed of the wave washers  71  and the flat washers  72 , a rotational resistance is provided. When the motor  2  is actuated, the driving shaft  21  rotates the crank plate  3  to move the connecting rod  4  so as to rotate the spindle link  5 . However, as the rotating torque induced by the spindle link  5  is smaller than the rotational resistance of the clutch member  7  in magnitude, the fan suspension tube  6  is moved by the spindle link  5  so as to facilitate the oscillation of the fan device  8 . This is the normal operating state in which the oscillation of the fan device  8  is actuated by the motor  2 . On the other hand, when it is desired to adjust the orientation of the fan device  8 , an external rotational force is applied onto the fan device  8 . When the external rotational force is greater than the rotational resistance of the clutch member  7 , the fan suspension tube  6  runs free and the oscillation angle can be freely adjusted as desired. In this manner, due to the provision of the clutch member  7 , the oscillation angle of the fan can be adjusted at the user&#39;s will. In addition, the damage to the oscillating mechanism or the motor resulting from inappropriately applied external force can be effectively precluded. 
         [0035]    While the present invention has been described and illustrated by the above embodiments and accompanying drawings, it is to be understood that this invention is not limited to these embodiments. The scope of this invention is defined by the appended claims.