Abstract:
Easy to attach and detach blades for overhead ceiling fans. A first version has a ceiling fan blade with keyhole slots that fit over flat topped fasteners on a mounting arm. Pulling the blade away from the arm locks the slots to the fasteners. A second version is similar to the first and has a decorative bottom cover having snappable tapered protrusions which attach through the keyholes and into mateable through-holes in the mounting arm connection. The third version has a protruding end portion of the blade that fits into a slot in the mounting arm where spring loaded pistons press into grooves in the protrusion end portion of the blade. Latching handles allow users to manually move the pistons. A fourth version has a slot in the blade which fits about a mateable housing in the mounting arm where opposing spring loaded pistons press into interior wall grooves in the slot of the blade. A fifth version has the blade with slots fit over the end of the mounting arm so that pulling the blade from the mounting arm causes spring loaded piston to interlock into a interior wall groove in the slot of the blade.

Description:
[0001]    This invention relates to ceiling fans, and in particular to easy to attach and detach blades for overhead ceiling fans.  
         BACKGROUND AND PRIOR ART  
         [0002]    Ceiling fans primarily have blades that are attached to the motor housing brackets by multiple screws and the likes. Screwing the blades onto a ceiling mounted motor is not only difficult to accomplish, but results in most ceiling fans in the market place having visible screws that are unsightly. Furthermore, the underside location of the fastener screws detract from the appearance of the ceiling fan itself. Another problem is from the ceiling fans having to run under continuous vibration conditions where the screws can loosen causing the blades to be accidentally released and result in damages to surrounding property and people in the vicinity.  
           [0003]    Furthermore, ceiling fan blades need to be cleaned to remove dirt and dust buildup. Current techniques have relied on manually holding brushes to the blades themselves which inherently tires the muscles in the cleaner&#39;s neck, shoulders, arms and hands. This messy cleaning with brushes causes the dirt to fall on both the cleaner and furniture and flooring below the fan.  
           [0004]    Attempts have been made at changing the attachment methods for the blades but still fail to overcome all the problems presented above. U.S. Pat. No. 4,884,947 to Rezek describes a cover for covering the blade to motor connections but still uses screw fasteners that have the problems described above. U.S. Pat. No. 5,180,284 to Monrose III et al. is entitled a “Detachable Blades for Ceiling Fans” and U.S. Pat. No. 5,433,585 to Yan has a removable pin connection for ceiling fan blades, but each of these patents still requires screw on brackets for both the motor housing and the blades. Similarly U.S. Pat. No. 4,396,352 to Pearce and U.S. Pat. No. 5,520,515 to Bailey et al. describe pitch adjustment attachments for ceiling fans but also still require screw on brackets between both the motor housing and the attached blades. A still further problem of many of these detachable ceiling fan type blades is that natural centrifugal forces of the spinning fans increases the chances of dislodging the blades.  
           [0005]    Thus, the need exists for a solution to the above presented problems with the prior art.  
         SUMMARY OF THE INVENTION  
         [0006]    The first objective of the present invention is to provide detachable blades for ceiling fans that are easy and quick to install.  
           [0007]    The second object of this invention is to provide detachable blades for ceiling fans that allow each blade to be locked in place to the motor housing.  
           [0008]    The third object of this invention is to provide detachable blades for ceiling fans that are adaptable to standard ceiling fan blades.  
           [0009]    The fourth object of this invention is to provide detachable blades for ceiling fans wherein the centrifugal force of the fans actually locks the blades in place.  
           [0010]    A first embodiment of the detachable blade and mounting arm assembly for a ceiling fan includes a blade having a three arranged keyhole slots at one end, and a ceiling fan motor connected mounting arm having an opposite end with three flat top shaped fasteners so that the keyholes are positioned over the the flat top shaped fasteners and locked by the longitudinal slot portions of the keyhole slot After which a spring clip holds the position of the blade to the mounting arm. Optionally, a gasket can be inserted between the blade and the mounting arm.  
           [0011]    A second embodiment is similar to the first but includes a decorative cap cover with upward projecting fastener having expandable tips for being inserted within the keyhole slots of the blade and snappably attach into mating through-holes on the mounting arm.  
           [0012]    A third embodiment has a slot in the end of the ceiling fan mounting arm for receiving a protruding end of the blade, the protruding end having angled comer edges. Spring loaded pistons rods in the mounting arm which face one another can fit into mateable grooves in the protruding end of the blade. The rods can be manually moved back to release the blades by handles.  
           [0013]    A fourth embodiment has a single planar blade with an end having a slot. The mounting arm has an end with two parallel plates separated from one another by a central housing having back to back spring loaded piston rods. Passing the slotted end of the blade around the central housing so that the piston rods expand into grooves within the interior walls of the slot opening of the blade. Overhanging portions of the parallel plates further support the sides of the blade about the slot. Latch handles attached to the piston rods allow a user to manually move the piston rods against their respective springs to release the blade from the mounting arm.  
           [0014]    A fifth embodiment has a single planar blade with an end having a slot with grooved interior walls. The mounting arm has an end with a top plate having uneven sides separated from a substantially rectangular bottom plate by a central housing having a spring loaded piston rod. The slotted end of the blade is positioned over the top plate so that the sides of the slot can abut against the bottom plate. Pulling the blade away from the mounting arm causes the piston rod to expand into a groove within the interior wall of the slot opening of the blade. The grooves and overhanging portions of the top plate and bottom plate prevents centrifugal forces caused from spinning the blade to dislodge the blade. Overhanging portions of the top and bottom plates further support the sides of the blade about the slot. A latch handle attached to the piston rod allows a user to manually move the piston rod its spring to release the blade from the mounting arm. 
       
    
    
       [0015]    Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.  
       BRIEF DESCRIPTION OF THE FIGURES  
       [0016]    [0016]FIG. 1A is an exploded view of a first preferred embodiment of the novel attachable and detachable blade and arm.  
         [0017]    [0017]FIG. 1B is a side view of the embodiment of FIG. 1A with the blade and arm attached to one another.  
         [0018]    [0018]FIG. 1C is a bottom view of FIG. 1B along arrow A.  
         [0019]    [0019]FIG. 1D is an enlarged view of the spring lock attachment for the embodiment of FIG. 1A.  
         [0020]    [0020]FIG. 1E is an enlarged view of a flat head screw fastener for use with embodiment of FIG. 1A.  
         [0021]    [0021]FIG. 1F is a side cross-sectional view of FIG. 1B with an optional gasket.  
         [0022]    [0022]FIG. 1G is an exploded view of the optional gasket and mounting arm of FIG. 1F.  
         [0023]    [0023]FIG. 2A is an exploded view of a second preferred embodiment of the detachable blade and arm.  
         [0024]    [0024]FIG. 2B is a bottom view of the second preferred embodiment of FIG. 2A.  
         [0025]    [0025]FIG. 2C is a perspective view of the upper surface of the cover cap used in FIGS.  2 A- 2 B.  
         [0026]    [0026]FIG. 2D is a cross-sectional view of an assembled FIG. 2A along the direction of arrow C 3 .  
         [0027]    [0027]FIG. 3A is a top exploded view of a third preferred embodiment of the detachable blade and arm.  
         [0028]    [0028]FIG. 3B is a side view of the mounting arm of FIG. 3A along arrow D 2 .  
         [0029]    [0029]FIG. 3C is a front view of the mounting arm of FIG. 3B along arrow D 3 .  
         [0030]    [0030]FIG. 3D is a top view of the mounting arm of FIG. 3A without a cover plate.  
         [0031]    [0031]FIG. 3E is a side view of the latching piston for use with the embodiment of FIGS.  3 A- 3 D.  
         [0032]    [0032]FIG. 4A is an exploded view of a fourth preferred embodiment of the detachable blade and arm.  
         [0033]    [0033]FIG. 4B is a side view of the mounting arm of FIG. 4A along arrow E 1 .  
         [0034]    [0034]FIG. 4C is a front view of the mounting arm of FIG. 4B along arrow E 2 .  
         [0035]    [0035]FIG. 4D is a top view of the mounting arm assembly of FIGS.  4 B- 4 C without a top plate cover.  
         [0036]    [0036]FIG. 4E is a side view of the latching piston for use with the embodiment of FIGS.  4 A- 4 D  
         [0037]    [0037]FIG. 5A is an exploded view of a fifth preferred embodiment of the detachable blade and arm.  
         [0038]    [0038]FIG. 5B is a side view of the mounting arm of FIG. 5A along G 1  and the blade positioned above.  
         [0039]    [0039]FIG. 5C is a front view of the mounting arm of FIG. 5B along arrow G 2 .  
         [0040]    [0040]FIG. 5D is a top view of the blade first positioned over the mounting arm.  
         [0041]    [0041]FIG. 5E is a top view of the blade and mounting arm of FIG. 5D after blade is pulled in the direction of arrow H 2 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0042]    Before explaining the disclosed embodiment of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.  
         [0043]    [0043]FIG. 1A is an exploded view of a first preferred embodiment  1  of the novel attachable and detachable blade  10  and mounting arm  40 . FIG. 1B is a side view of the embodiment  1  of FIG. 1A with the blade  10  and arm  40  attached to one another. FIG. 1C is a bottom view of FIG. 1B along arrow A. FIG. 1D is an enlarged view of the spring lock attachment  50  for the embodiment of FIG. 1A. FIG. 1E is an enlarged view of a flat head screw fastener  22  for use with embodiment  1  of FIG. 1A. Referring to FIDS.  1 A- 1 E, planar shaped ceiling fan blade  10  includes three keyhole slots arranged in a triangular pattern through the wide planar portion  11  of the blade  10 . Each keyhole slot includes a wide diameter bases  12 ,  14 ,  16 , and a narrow longitudinal portion  13 ,  15 ,  17 , respectively. Mounting arm  40  includes a flat generally heart shaped blade mounting portion  41  having decorative ridged edge  44  across one end and a narrower region  45  connecting to a curved narrow connecting arm portion  46 . Flat headed fasteners such as Philips head or regular head screws  22 ,  24 ,  26  have threads(only thread  23  is shown in FIG. 1E) which screwably attach to mateably threads within hollow stems  33 ,  35 ,  37 , respectively. A spring clip  50  has an elongated metal steel strip base with one end  51  wrapped about stem  37  above raised step  57  and the other end  52  abuting against raised step  59 . Spring bent tab  54  has a flat strip base  50  can be further attached to an upper portion of curved narrow connecting arm portion  46  by and adhesive. The other end of mounting arm  40  includes a curved ceiling fan motor mount  48  having through-holes  49  that enable fasteners such as screws(not shown) for mounting to a centrally located conventional ceiling fan motor  90 (represented in FIG. 1C). Optionally, rubber washers/grommets can be used with stems  33 ,  35 ,  37  to provide vibration isolation and a closer fit between the wood and metal components.  
         [0044]    To be used, the wide diameter areas  12 ,  14 , and  16  are positioned to fit down direction of arrow B 1 , over and about the flat headed fasteners  22 ,  24 , and  26 . Simultaneously, the bent tab  54 ,of the spring clip  50  protrudes through longitudinal key slot opening  17 . Sliding and pulling the blade  10  outward in the direction of arrow B 2 , causes the bent tab  54  to depress in the direction of arrow B 4 . As tip  11  clears over, bent tab  54  pops up so that the bottom face of blade  10  abuts flush against upper surface  42  of blade mounting portion  41 . The natural expansion of bent tab  54  of spring clip  50  keeps blade tip  11  pushed in the direction of arrow B 2  allowing keyhole narrow longitudinal portions  13 ,  15 , and  17 , to surround stems  33 ,  35 , and  37 , respectively. By depressing bent tab  54  in the direction of arrow B 4 , blade  11  can be pushed in the direction of arrow B 5  to allow the keyhole wide diameter areas  12 ,  14  and  16  to be able to pass about flat headed fasteners  22 ,  24 ,  26 , thereby allowing the blade to be detached from the mounting arm  40 .  
         [0045]    [0045]FIG. 1F is a side cross-sectional view of FIG. 1B with an optional gasket  60 . FIG. 1G is an exploded view of the optional gasket  60  and mounting arm  40  of FIG. 1F. Referring to FIGS. 1F and 1G, a flat gasket formed of material such as but not limited to rubber and plastic can be shaped to conform to the perimeter shape of hear shaped blade mounting portion  41  allowing the blade  10  to be more tightly attached to mounting arm  40 .  
         [0046]    [0046]FIG. 2A is an exploded view  100  of a second preferred embodiment of the detachable blade  110 , mounting arm  140  and cover cap  160 . FIG. 2B is a bottom view of the second preferred embodiment  100  of FIG. 2A. FIG. 2C is a perspective view of the upper surface  161  of the cover cap  160  used in FIGS.  2 A- 2 B. FIG. 2D is a cross-sectional view of an assembled embodiment  100  of FIG. 2A along the direction of arrow C 3 .  
         [0047]    Referring to FIGS.  2 A- 2 D, embodiment  100  includes planar shaped ceiling fan blade  110  having three keyhole slots arranged in a triangular pattern through the wide planar portion  111  of the blade  110 . Each keyhole slot includes a wide diameter bases  113 ,  115 ,  117  and a narrow longitudinal portions  112 ,  114 ,  116 , respectively. Mounting arm  140  includes a flat generally paddle shaped blade mounting portion  141  having an outer wider end  144  and a narrower region  145  connecting to a curved narrow connecting arm portion  146 . Flat headed fasteners with stems(such as those described in the previous embodiment)  122 ,  124 ,  126  are arranged in a triangular pattern on the underside  142  of blade mounting portion  141 . The other end of mounting arm  140  includes a curved ceiling fan motor mount  148  having through-holes  149  that enable fasteners such as screws(not shown) for mounting to a centrally located conventional ceiling fan(not shown). A cover cap  160  has a molded plastic base  161  with a decorated ridged end  168  and an opposite narrower tip end. Stud projections  162 ,  164  and  166  each being expandable and depressible with flattened tips, each having tapered bases  163 ,  165 ,  167  can be molded as part of the plastic base  161 .  
         [0048]    In operation, each wide diameter bases wide diameter bases  113 ,  115 ,  117  of the keyhole slots in the blade  110  are moved in the direction of arrow C 1  to overly respective flat head fasteners  122 ,  124  and  126  until blade  110  is flush to abut against surface  142 . Then blade  110  is moved in the direction of arrow C 3  until the stem portions of the respective flat head fasteners  122 ,  124  and  126  surround respective keyhole narrow longitudinal portions  112 ,  114 ,  116 . Next cover cap  160  is moved in the direction of arrow C 2  so that expandable stud projections  162 ,  164  and  166  pass through wide diameter openings  113 ,  115  and  117  and through narrower matching through-holes  132 ,  134  and  136  after which the angled heads of the stud projections expand to snappably lock the cover cap  160  and blade  110  to mounting arm  140 . Individually squeezing each of the angled stud projection tips and reversing the assembling steps allows the blade  110  to be removed.  
         [0049]    [0049]FIG. 3A is a top exploded view  200  of a third preferred embodiment of the detachable blade  210  and mounting arm  240 ,  250 . Components  246  and  248  conform to similar components of the preceding embodiments. FIG. 3B is a side view of the mounting arm  240 ,  250  of FIG. 3A along arrow D 2 . FIG. 3C is a front view of the mounting arm  240 ,  250  of FIG. 3B along arrow D 3 . FIG. 3D is a top view of the mounting arm  240 ,  250  of FIG. 3A without a cover plate  250 . FIG. 3E is a side view of the latching piston  264  for use with the embodiment  200  of FIG. 3A. Referring to FIGS.  3 A- 3 E, embodiment  200  includes a mounting arm  240  with blade mounting section wherein a semi-circular top flat plate  250  is attached to a like bottom plate  270  by screw fasteners  251  with a rectangular slot opening  260  therebetween. Two latching pistons  262 ,  264  each having latching handles  263 ,  267  pass through openings  252  in top plate  250 . inner springs  265  and  269  allow the pistons  262 ,  264  to move in the direction of arrows D 4  and D 5 , respectively within cylindrical housings  272 ,  274 . Inner end  212  of ceiling fan blade  210  has a narrow width portion with angled outer edges  213 ,  215  and interior facing grooved indentations  217 ,  219 . Moving blade  210  in the direction of arrow D 1  inserts narrow planar end  212  into slot  260  so that sides  214 ,  216  slide along interior sides  261 ,  269  of slot  260 . The outer angled edges  213 ,  215  cause pistons  262 ,  264  to compress their respective springs  269  and  265 , respectively, until the pistons  262 ,  264  expand and snap into the grooved indentations  217 ,  219  of the blade  210 . To remove the blade  210 , latching handles  263 ,  267  are manually moved in the direction of arrows D 4  and D 5 , respectively, allowing blade  210  to be separated from slot  260  of mounting arm  240 .  
         [0050]    [0050]FIG. 4A is an exploded view of a fourth preferred embodiment  300  of the detachable blade  310  and mounting arm  340 . FIG. 4B is a side view of the mounting arm  340  of FIG. 4A along arrow E 1 . FIG. 4C is a front view of the mounting arm  340  of FIG. 4B along arrow E 2 . FIG. 4D is a top view of the mounting arm  340  of FIGS.  4 B- 4 C without a top plate cover  350 . FIG. 4E is a side view of the latching piston  364  and latching handle  367  for use with the embodiment  300  of FIGS.  4 A- 4 D. Referring to FIGS.  4 A- 4 E, mounting arm  340  includes curved narrow connecting arm portion  346  and curved ceiling fan motor mount  348  similar to those described in the previous embodiments. Arm mount  340  further includes two parallel plates  350  and  370  which are connected to one another through a central housing  382  and  384  by screw fasteners  351 . The width of central housing  382 ,  384 , is smaller that the width of the plates  350 , 370  so that edges of the plates  350 ,  370  form overhanging lips  381 ,  383  to the sides of central housing  382 ,  384 (shown more clearly in FIG. 4C. Between central housings  382 ,  384  are dual chambers  387 ,  385  for supporting two opposing piston rods  362 ,  364  each having angled outer tips. Piston rods  362 ,  364  are supported at their respective rear portions by opposing springs  365  and  369 , respectively, so that the piston rods  362  and  364  can compress within their respective chambers  387  and  385 .  
         [0051]    Referring again to FIGS.  4 A- 4 E, a partial view of a single planar blade  310  is shown having a generally rectangular shaped slot opening  311 ,  313 ,  315  through the blade  310  at one end and opposing interior grooves  317 ,  319 . When blade  310  is moved in the direction of arrow E 3 , the inner side walls  313 ,  315  of the slot pass through the overhanging lip areas  381 ,  383  between the parallel plates  350  and  370  of the mounting arm  340 . Outer angled tips of piston rods  362 ,  364  cause the piston rods to compress against their respective springs  365 ,  369  until side grooves  317  and  319  within the blade  310  allow the piston rods  362 ,  364  to expand into the side grooves  317 ,  319  locking the blade  310  to the mounting arm  340 . Latch handles  363  and  367  can be manually moved towards each other to allow the blade  310  to be separated from mounting arm  340 .  
         [0052]    [0052]FIG. 5A is an exploded view of a fifth preferred embodiment  400  of the detachable blade  410  and mounting arm  440 . FIG. 5B is a side view of the mounting arm  440  of FIG. 5A along G 1  and the blade  410  positioned above. FIG. 5C is a front view of the mounting arm  440  of FIG. 5B along arrow G 2 . FIG. 5D is a top view of the blade  410  first positioned over the mounting arm  440 . FIG. 5E is a top view of the blade  410  and mounting arm  440  of FIG. 5D after blade  410  is pulled in the direction of arrow H 2 .  
         [0053]    Referring to FIGS.  5 A- 5 C, mounting arm  440  includes curved narrow connecting arm portion  446  and curved ceiling fan motor mount  448  similar to those described in the previous embodiments. Arm mount  440  further includes top plate  450  with uneven sides and bottom substantially rectangular planar plate  470  which are connected to one another through a central housing  482  and  484  by screw fasteners  451 . Central housing  484  has side extension portions  489  on both sides(only one is shown) and central housing  482  has front side extension portions  487  on both sides(only one is shown). Top plate  450  has opposing side wings  452 (only one is shown) and front edge wings  454 (only one is shown). Side wings  452  and  454  are larger in size than side extension portions  487 ,  489 . The width of central housing  482 ,  484  with side extensions  487 ,  489 , is smaller than the width of the plates  450 ,  470  so that side wings  452 ,  454  of the plates  450 , and sides  471 ,  473  of bottom plate  470  form overhanging lips to the sides of central housing  482 ,  484 (shown more clearly in FIG. 5C).  
         [0054]    Referring to FIG. 5A, planar blade  410  has a generally rectangular shaped slot formed between opening tip portions  413 ,  415 , first cut-out rectangular grooves  414 ,  416 , opposing angular grooves  417 ,  419 , and extending rear tip portions  412 ,  418  with rear cut-out rectangular grooves  421 ,  422  and end wall  411 .  
         [0055]    Assembling the blade  410  to the mounting arm  440  is first shown by FIG. 5B, where front and rear tip portions  413 ,  415  and  412 , 418  of blade  410  are positioned parallel to and over and in front of top plate wings  452  and  454 . FIG. 5D is a top portion of blade  410  after being laid over mounting arm  440  so that interior extending portions  413 ,  415 ,  412 ,  418  of the blade slot  410  fit about wings  452 ,  454  of top plate  450  and central housing side extensions  487 ,  489  to abut against bottom plate  470 . Next blade  410  is pulled away from mounting arm  440  in the direction of H 2  as finally shown in FIG. 5E so that piston rod  464  compresses into chamber  485  and then extends outward into blade slot cut-out groove  414  and central housing side extensions  489  abut against portions of blade slot tip portions  413 ,  415 . Blade slot tip portions  413 ,  415  also become sandwiched between top plate wings  452 ,  454  and bottom plate lips  471 ,  473  of bottom plate  470 .  
         [0056]    Furthermore, central housing side extensions  487  abut against blade slot rear tip portions  412 ,  418 . Blade slot rear tip portions  412  and  418  also become sandwiched between top plate wings  454  and bottom plate lips  471 ,  473 . The final assembled arrangement of FIG. 5E keeps blade  410  locked into mounting arm  410  when centrifugal forces occur when the blade  410  is spinning. To remove the blade  410  from the mounting arm  440 , latch handle  467  is moved back against spring  469 , and the above steps are then reversed.  
         [0057]    While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.