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.

Description:
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. 
     FIG. 5 is an isometric, exploded view, depicting an alternate embodiment of the present invention. 
    
    
     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 20a (FIG. 2) extending therethrough for receiving its corresponding post 32, and two other openings 20b 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 18a and an opposite curved outer surface (FIG. 1). A slot 18b is formed in each block 18 and extends from the inner surface 18a of the block into, but not completely through, the block. The slot 18b 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 30a and 30b are formed in the upper surface of the flange 30 and, as shown in FIG. 2, a pair of spring loaded balls 44a and 44b are provided in the mounting block 18 for extending in the recesses. The ball 44a 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 44a downwardly as shown so that a lower portion of the ball projects slightly from the end of the shaft and into the slot 18b. The other ball 44b is mounted in the block in the same manner, and the balls 44a and 44b are spaced so as to align with, and extend in, the recesses 30a and 30b, respectively, when the flange 30 is inserted in the slot 18b, 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 18b and moving the flange radially outwardly until the flange is secure in the slot. In this position, the balls 44a and 44b in the block are urged into the recesses 30a and 30b of the corresponding flange 30 in the manner describe above to lock the flange 30 in the slot 18b. 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 18b 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. 
     FIG. 5 depicts an alternate embodiment of the present invention which includes many identical components of the previous embodiment which are given the same reference numerals. According to the embodiment of FIG. 5, a continuous, annular, ring-like mounting member 50 is provided in place of the plurality of mounting blocks 18 of the previous embodiment. A plurality of angularly-spaced slots 50b are formed in the member which are identical to the slots 18b of the previous embodiment and which function to receive the flange 30 of the arm 22 in the manner described above in connection with the previous embodiment. Otherwise, all of the components of the embodiment of FIG. 5 are identical to those of the previous embodiment including the screws 19 that bolt the member 50 to the end casing 16, and the balls 44a and 44b which extend in the recess is the member 50 and function in the same manner as the previous embodiment. 
     Thus the embodiment of FIG. 5 enjoys all of the advantages of the previous embodiment. 
     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 22d and the guide pins 22e of each arm 22 can be fabricated separately and press fitted, or attached in any other known manner, to the arm. 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.