Patent Publication Number: US-6902375-B2

Title: Quick connect ceiling fan blade

Description:
TECHNICAL FIELD 
     This invention relates to ceiling fans and more specifically to mechanisms by which their fan blades are mounted and dismounted. 
     BACKGROUND OF THE INVENTION 
     Electrically powered ceiling fans typically have a motor mounted within a stationary housing that is suspended from a ceiling. In operation, the motor rotates an annular array of individual extensions in the form of blade irons. Each blade iron is associated with a blade mounted thereto. 
     Ceiling fans are usually sold at retail with their blades packed separately from the fan housing or blade irons for compactness. The housing is normally mounted in suspension from the ceiling through a downrod and then the blades are mounted to the blade irons. To do this, the blades have been mounted to the blade irons with screws or bolts. This has been cumbersome and tedious as the installer has had to be elevated on a ladder or platform and work above his head. This work has entailed aligning the mounting holes of the blade and blade iron and torguing the screws all while having to hold the blade above his head and often under poor lighting conditions. For blade replacement, the same task has been involved. 
     Ceiling fan blades have been designed to be coupled to a blade iron for quick mounting and dismounting, as shown in U.S. Pat. No. 6,010,306. This ceiling fan design shows a blade iron having three flat headed posts adapted to be slid into the narrow portion of key-hole shapes slots within the corresponding blade. The blade is prevented from moving by a spring blade lock which abuts the inward end of the blade. A problem however with this design is that the vibration or movement of the blade causes the flat head of the posts to rub against the blade, which oftentimes is made of a rather soft material such as wood. This rubbing may cause the deterioration of the blade adjacent the key hole slot, thereby causing a loose fitting or even the wearing through of the blade to such a degree as to cause the blade to dislodge from the underlying blade iron. This loosening of the blade is an obvious danger that should be avoided. 
     Accordingly, it is seen that a need remains for a ceiling fan capable of having its blades mounted and dismounted in a more efficient and easier manner. It is to the provision of such therefore that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     In a preferred form of the invention a ceiling fan comprises an electric motor and an annular array of blade irons mounted to the motor, each blade iron having a support member and at least one locking pin extending from the support member. The ceiling fan also has a ceiling fan blade associated with each blade iron of the annular array of blade irons, each blade having at least one locking pin mounting hole. Lastly, the ceiling fan includes a locking plate adapted to be releasably coupled to the locking pin as the locking pin extends through the locking pin mounting hole of the fan blade. With this construction, the blades may be mounted to the blade irons by passing the locking pin through the fan blade locking pin mounting hole and then coupling the locking plate to the locking pin to capture the fan blade between the blade iron and the locking plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a perspective view of the top of a ceiling fan that embodies principles of the invention in its preferred form. 
         FIG. 2  is an exploded view of parts employed in mounting one of the fan blades. 
         FIG. 3  is a cross-sectional view of the parts of  FIG. 2  shown in an unlocked position 
         FIG. 4  is a cross-sectional view of the parts of  FIG. 2  shown in a locked position. 
     
    
    
     DETAILED DESCRIPTION 
     With reference next to the drawings, there is shown a ceiling fan  10  having a motor housing  11  suspended from an unshown ceiling by a downrod  12 . An electric motor  13  is mounted within the housing  11  and connected to a source of electric power by wires that extend through the downrod  12 . The motor rotatably drives an annular array of blade irons  14 , each having a blade  15  and a locking plate  17  coupled thereto. 
     Each blade iron  14  has a motor mounting flange  21  configured to be coupled with the electric motor  13  for rotation, a neck  22 , and a blade support member or mounting portion  23 . Each blade iron mounting portion  23  has a top surface or edge  25  and three mounting or locking pins  26  extending past the top surface  25  towards the ceiling. Each locking pin  26  has a stepped shaft  27  extending to a head  28  distal and set above the top surface  25 . The head  28  has a width larger than the width of the shaft  27 . 
     Each blade  15  has three locking pin mounting holes  31  extending therethrough, a top surface  32  and a pair of alignment pins  33  extending from the top surface  32 . The three locking pin mounting holes  31  are configured and oriented to receive the blade iron locking pins  26 . 
     Each locking plate  17  has a bottom surface  35 , a top surface  36 , three key-hole shaped locking pin mounting holes  37 , a pair of alignment pin slots  38  and a thumb tab  39 . The three locking pin mounting holes  37  are configured and oriented to receive and releasably lock with the blade iron locking pins  26 . Each locking pin mounting hole  37  has an enlarged portion  41  configured to allow the passage of the locking pin head  28  therethrough and an elongated narrowed portion  42  configured to fit snugly about the locking pin shaft  27  beneath the head  28 . The locking pin heads  28  are positioned a select distance from the top surface  25  of the blade iron  14  so that the blade  15  fits snugly between the head  28  and the top surface  25 . The two alignment pin slots  38  are configured to receive the two blade alignment pins  33 . 
     In use, the downrod  12  is coupled to the ceiling with the motor housing  11  coupled to the opposite end of the downrod with the blade irons  14  already mounted to the motor  13 . Each blade  15  is mounted to a corresponding blade iron by lowering the blade  15  onto the underlying blade iron  14  so that the three locking pins  26  extend through the blade locking pin mounting holes  31 . With the blade  15  resting upon the top surface  25  of the blade mounting portion  23  the locking plate  17  is then lowered onto the top surface  32  of the blade  15  with the locking pins  26  extending through the enlarged portion  41  of the blade locking pin mounting holes  37  and the blade alignment pins  33  extending through the alignment pin slots  38 . The head  28  of the locking pins  26  should be positioned slightly above the top surface  36  of the locking plate  17 , as shown by the unlocked position of the locking plate in FIG.  3 . 
     Next, an installer manually pushes upon the thumb tab  39  of the locking plate  17  to slide the locking plate outboard to its locked position, thereby forcing the locking pins  26  into the narrowed portion  42  of the locking plate mounting holes  37 , as shown in FIG.  4 . The head  28  of the locking pins  26  should be pressed firmly against the top surface  36  of the locking plate to prevent relative movement of the locking plate. The term outboard is meant to represent movement away from the fan&#39;s axis of rotation. 
     With the locking pins  26  locked in position against the blade locking pin mounting holes  31  and the top surface  36  of the locking plate  17 , the blade  15  is captured between the locking plate  17  and the blade mounting portion  23  of the blade iron  14 . As such, the locking pins  26  prevent lateral movement of the blade  15  relative to the blade iron  14 , i.e., locking the position of the blade  15  upon the blade iron  14 . This locking of the blade may be accomplished simply and quickly by a single installer as this may be done without the use of tools and without screwing in multiple mounting screws. The ability to lock the blades in place without the use of tools solves a problem long associated with mounting the blades of ceiling fans of the prior art. 
     It should be understood that the use of a locking plate  17  spreads the contact surface between the locking means between the blade and the blade iron onto a large contact surface area. By enlarging this contact surface area any vibration or other movement of the components during fan operation does not result in the eventual wearing down of the contact surfaces, which may cause the loosening of the blade from the blade iron. Again, the elimination of the wearing problem solves another problem long associated with the prior art. 
     The blade  15  may likewise be dismounted from the blade iron  14  by simply moving the locking plate  17  inboard to a position wherein the locking pin heads  28  may pass back through the enlarged portion  41  of the locking plate mounting holes  37  and blade mounting holes  31 . This may be accomplished by an operator pressing inboard upon the locking plate thumb tab  39 . 
     The stepped shaft  27  of the locking pins  26  allow the lowermost portion to fit snugly within the blade mounting holes  31  while having the thinner portion exposed above the top surface  32  of the blade so as to fit snugly within the narrowed portion  42  of the locking plate mounting holes  37 . This stepped structure aids in maintaining a tight fit between all the components. 
     It should be understood that while the preferred embodiment of the invention shows the use of three locking pins, such should not be considered to be a limitation regarding the number of locking pins. Alternative designs of the present invention may utilize any number of locking pins. Also, it should be understood that the alignment pins are utilized to aid in the movement of the locking plate between a locked and unlocked position. However, these alignment pins may be eliminated while still practicing the invention. 
     It thus is seen that a quick connect ceiling fan blade is now provided which enables the blade to be mounted and dismounted easily, quickly and in a reliable and secure manner. While this invention has been described in detail with particular references to the preferred embodiments thereof, it should be understood that many modifications, additions and deletions, in addition to those expressly recited, may be made thereto without departure from the spirit and scope of the invention as set forth in the following claims.