Patent Abstract:
A fan assembly according to which a block member is connected to a rotor end casing and an arm member having a blade connected thereto is mounted to the block member. One of the members has a radially extending slot formed therein and the other member has a mounting flange adapted to extend into the slot when the arm is moved radially outwardly relative to the block member to mount the arm to the block member without the need for additional components.

Full Description:
This is a continuation of U.S. Ser. No. 09/196,798 filed Nov. 20, 1998, now U.S. Pat. No. 6,139,276. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a ceiling fan assembly and a method for assembling same, and, more particularly, to such an assembly and method in which the assembly can be assembled relatively easily and quickly using a minimum number of parts. 
     Rotating fans that are mounted to the ceilings of homes and businesses are very popular. These types of fans consist of a plurality of angularly-spaced blades and a plurality of arms that connect the blades to the rotor portion of an electric motor mounted in a housing, which, in turn, extends from a ceiling. Since the blades, arms and the motor are often manufactured and shipped separately, they must be assembled and mounted at the site. However, this assembly and mounting is relatively difficult and time-consuming since each blade must be attached to its arm by a plurality of fasteners, and each arm is attached to the rotor end casing by a plurality of fasteners. Since there are usually five blades and arms, the labor costs involved in assembling and mounting the complete fan assembly constitutes a very high percentage of the overall cost of the assembly. This difficultly in assembly is compounded by the fact that the rotor end casing of the fan motor is initially mounted to the ceiling the above-mentioned arms and blades often have to be mounted to the end casing in its elevated position. 
     Therefore, what is needed is a fan assembly and a method of assembling same in which the fan blades can be easily and quickly attached to the arms, and the arms can be easily and quickly attached to the motor even when mounted to the ceiling, thus considerably reducing the labor costs in assembling and mounting the fan assembly. 
     SUMMARY OF THE INVENTION 
     An embodiment of the present invention, accordingly, is directed to a ceiling fan assembly and method for assembling same according to which a block member is connected to a rotor end casing and an arm member having a blade connected thereto is mounted to the block member. One of the members has a radially extending slot formed therein and the other member has a mounting flange adapted to extend into the slot when the arm is moved radially outwardly relative to the block member to mount the arm to the block member without the need for additional components. 
     Several advantages result from this arrangement. For example, the use of a plurality of nuts, bolts and,;screws is eliminated and the blades can be connected to the arms, and the arms to the rotor, using a minimum of fasteners. Also, the centrifugal forces causes by normal rotation of the fan tend to force the flange radially outwardly relative to the slot and thus secure the connection of the arm to the mounting block. Also, the fan assembly can be assembled and mounted relatively easily and quickly thus considerably reducing the labor costs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric, partially exploded, view of the fan assembly of an embodiment of the present invention. 
     FIG. 2 is an enlarged, isometric, exploded view depicting one blade and its associated components of the fan assembly of FIG.  1 . 
     FIG. 3 is a sectional view of a portion of the fan assembly of FIGS. 1 and 2. 
     FIG. 4 is an enlarged isometric, partial view of a component of the fan assembly of FIGS. 1-3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 of the drawings depicts the fan assembly of an embodiment of the present invention which assembly is referred to, in general, by the reference numeral  10  and which includes a housing  12  connected to a ceiling of a building by a mounting rod  14 . It is understood that the mounting rod  14  is connected to the ceiling in any known manner, and that electrical conductors extend from an electrical box (not shown) mounted to the ceiling, through the rod, and into the interior of the housing  12 . A conventional electrical motor is provided in the housing  12  that includes a stator (not shown) and a rotor that includes an end casing  16  that protrudes slightly through an opening in the surface of the housing. 
     Five arcuate mounting blocks  18  are mounted to the end casing  16  by a plurality of screws  19  extending through aligned openings in the mounting blocks and the casing. The mounting blocks  18  are mounted with the corresponding ends of each adjacent pair in close proximately so that the assembled blocks together form an annulus extending downwardly from the end casing  16 . 
     Five elongated blades  20  are respectively mounted to the end portions of five mounting arms  22 , and the details involving the connection of a blade  20  to its corresponding arm  22  are better shown in FIGS. 2 and 3. More particularly, each arm  22  includes a relatively wide mounting portion  24  that has openings extending therethrough to reduce its weight, and a necked-down portion  26  one end of which extends from the portion  24 . The other end portion of the necked-down portion  26  is bent to form a portion  28  which extends substantially vertically as viewed in the drawing, and a mounting flange  30  is formed at the end of the portion  28 . 
     A externally threaded post  32  and two guide pins  34  all extend from the upper surface of the arm portion  26 . Preferably, arm portions  24 ,  26 ,  28 , and  30 , as well as the post  32  and the guide pins  34  are all molded integrally. 
     The corresponding end of each blade  20  has an enlarged opening  20   a  (FIG. 2) extending therethrough for receiving its corresponding post  32 , and two other openings  20   b  for receiving the corresponding two guide pins  34 , respectively. An internally threaded cap  36  threadedly engages the post  32  to retain the blade  20  to the arm  22 , and a seal ring  38  extends between the lower outer surface of the post  32  and the inner wall of the cap  36 . A counter bore is provided in the post  32  which receives a ball  40 , and a spring  42  extends between the ball and the bottom of the counter bore to urge the ball upwardly, as viewed in FIG. 3, and tighten the threaded connection between the cap  36  and the post  32 . 
     As better shown in FIG. 2, each block  18  has a curved inner surface  18   a  and an opposite curved outer surface (FIG.  1 ). A slot  18   b  is formed in each block  18  and extends from the inner surface  18   a  of the block into, but not completely through, the block. The slot  18   b  is sized so as to receive the flange  30  of the arm  22  in a relatively tight fit. To this end, and as better shown in FIG. 4, the side walls of the flange  30  are tapered inwardly. 
     As also shown in FIG. 4, a pair of spaced recesses  30   a  and  30   b  are formed in the upper surface of the flange  30  and, as shown in FIG. 2, a pair of spring loaded balls  44   a  and  44   b  are provided in the mounting block  18  for extending in the recesses. The ball  44   a  is shown in detail in FIG. 3, and is mounted in a bore formed in an externally threaded shaft  46  which extends through an opening in the block  18 . A spring  48  is disposed in the shaft  46  for urging the ball  44   a  downwardly as shown so that a lower portion of the ball projects slightly from the end of the shaft and into the slot  18   b . The other ball  44   b  is mounted in the block in the same manner, and the balls  44   a  and  44   b  are spaced so as to align with, and extend in, the recesses  30   a  and  30   b , respectively, when the flange  30  is inserted in the slot  18   b , to retain the flange in the slot. 
     To mount the ceiling fan  10  to a ceiling, the rod  14  (FIG. 1) is connected to the ceiling in any known manner, and the housing  12  is connected to the rod with the lower portion of the rotor end casing  16  protruding slightly from the lower end of the housing  12  as shown in FIG.  2 . The blocks  18  are attached to the end casing  16  by the screws  19 , and each blade  20  is attached to the arm  22  in the manner described above. The flange  30  of each arm  22  is then inserted in its corresponding block  18  by positioning the flange radially inwardly from, and aligned with, the slot  18   b  and moving the flange radially outwardly until the flange is secure in the slot. In this position, the balls  44   a  and  44   b  in the block are urged into the recesses  30   a  and  30   b  of the corresponding flange  30  in the manner describe above to lock the flange  30  in the slot  18   b . In this manner, rotation of the fan creates centrifugal forces that urge each flange  30  in a radial outwardly direction to further secure the flanges in their respective slots  18   b  in the blocks  18 . 
     Although only one blade  20 , arm  22  and mounting block  18  are shown in FIGS. 2 and 3, it is understood that the other blades, arms and mounting blocks are identical and are connected together and mounted to the end casing  16  in the same manner. 
     As a result of the foregoing, the use of a large number of nuts, bolts and screws is eliminated and the blades can be connected to the arms, and the arms to the rotor, using a minimum of fasteners. Also, the arms are connected to end casing by simply inserting them in the slotted mounting blocks without the need for a retaining ring, or the like. Also, the centrifugal forces causes by normal rotation of the fan tend to force the flanges radially outwardly in their corresponding slots and thus secure the connection of the arm to the mounting block. Also, the fan assembly can be assembled and mounted relatively easily and quickly thus considerably reducing the labor costs. 
     It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, the number of blades  20  used in each embodiment can vary within the scope of the invention. Also, the post  22   d  and the guide pins  22   e  of each arm  22  can be fabricated separately and press fitted, or attached in any other known manner, to the arm. Further, rather than employ individual mounting blocks, the blocks can be formed integrally into a continuous annulus, or ring-like member. Moreover, the latter annulus, or ring-like member may be formed integrally with the end casing  16  thus eliminating the need to fasten the individual blocks or annulus to the end casing with the fasteners  19 . 
     It is understood that other modifications, changes and substitutions are intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

Technology Classification (CPC): 5