Patent Abstract:
A mounting system for mounting a rotary member to a stationary member. The mounting system includes a carrier adapted to engage the rotary member, wherein the carrier includes a mounting leg portion which terminates into a pair of resilient leg portions. The carrier may also further include a spring member adapted to engage a first surface of the stationary member. At least one of the legs in the pair of resilient leg portions includes a turned-out portion adapted to engage a second surface of said stationary member.

Full Description:
BACKGROUND 
     When electronic components operate, they produce heat. In some, low power, applications, this heat can be adequately removed using free convection cooling. However, in many applications, free convection cooling (the un-aided movement of air) does not provide sufficient cooling to prevent overheating (and possibly premature failure) of electronic components. In applications where free convection cooling does not offer sufficient cooling capacity, electric fans are often used as a low cost way of moving ambient air across the electronic components at a higher rate than that possible using free convection cooling. Accordingly, the use of cooling fans is often employed as a low cost solution for keeping electronic components operating within the acceptable temperature ranges specified by the electronic component manufacturers. 
     Cooling fans are often integrated with an enclosure which houses, amongst other components, the electronic components to be cooled by the fan. The cooling fan is often mounted to the enclosure using fasteners such as screws, dowel pins, rivets, or the like. Although this fastening technique is widely used, it significantly increases the cost of the product due to the labor and tools that are needed to install the fasteners and the handling costs associated with handling the fasteners. 
     Embodiments set forth herein disclose a system for eliminating fasteners traditionally used for securing cooling fans to an enclosure. The embodiments disclosed herein can be utilized in various applications including the automotive, computer, electronic instrumentation, or in any industry where the forced movement of air is used as a temperature controlling medium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an embodiment of the cooling fan mounting system of the present invention used in conjunction with a computer tower. 
         FIG. 2  is an exploded enlarged isometric view of encircled portion  2  of  FIG. 1  from a different perspective. 
         FIG. 3  is a partial cross-sectional view taken substantially through lines  3 - 3  of  FIG. 2 . 
         FIGS. 4A-4I  are a series of grouped interior, exterior, and side views of the position of the fan enclosure (with respect to the panel on which it is mounted) at various stages of fan assembly installation. 
     
    
    
     DETAILED DESCRIPTION 
     Now referring to  FIG. 1 , an embodiment of the cooling fan assembly  12  of the present invention is shown in use with a panel  14  of computer tower  10 . Although cooling fan assembly  12  can be used in any computer application where forced air cooling is necessary, it is not limited to those applications and one skilled in the art will readily recognize that the cooling fan assembly of the present invention is applicable in any application where forced air movement is relied upon for adequate cooling of any heat generating system (electrical, mechanical, chemical, or the like). 
     Now referring to  FIG. 2  and  FIG. 3 , panel  14  can comprise any stationary member to which cooling fan assembly  12  is to be mounted. However, typically cooling fans are mounted to sheet-like stationary members (typically sheet metal panels). Throughout this disclosure, the device to which assembly  12  is mounted will be primarily referred to as a panel or stationary member; however, structures other than panels are fully contemplated within the scope of this disclosure. Panel  14  provides the mounting interface for supporting cooling fan assembly  12 . Cooling fan assembly  12  includes a motor  16  which is used to rotate a fan blade  18  by way of a motor output shaft  20 . In one embodiment of the present invention, motor  16  is an electrical motor which receives its electrical power requirements via power conductors  22 . Although in many applications, the preferred embodiment of motor  16  is an electric motor, it is well within the scope of this invention to use non-electric motors as the primary mover for moving fan blade  18 . Other primary movers that might be appropriate in various applications, include hydraulic motors, pneumatic motors, and the like. In some embodiments, depending on the type of electric motor that may be used, it may be convenient or cost effective to mount electronic motor control components  24  on, or about, motor  16 . In other applications, it may not be appropriate to mount motor control components on, or about, motor  16  and in such cases, motor control components  24  can be mounted separate from motor  16 . 
     In the majority of applications, it is most appropriate to establish the rotation of fan blade  18  such that it moves warm air, designated by arrows  26 , from the interior of an enclosure to the exterior of the enclosure through enclosure exhaust portals  28 . The enclosure is typically fitted with enclosure intake portals (intake portals not shown) which allow ambient air to enter into the enclosure interior to replace the air exhausted by cooling fan assembly  12 . 
     In one embodiment the motor  16  includes non-rotatable housing  30  which houses the operative components of motor  16 . The housing  30  is coupled to a motor carrier  32 . In one embodiment of the present invention, motor housing  30  is integrally formed (such as using plastic injection molding techniques) with motor carrier  32  to form an integrated unit. 
     Motor carrier  32  includes a plurality of mounting legs  34 . In one embodiment, each mounting leg  34  terminates into a pair of resilient leg portions  36  which are separated by a compression gap  38 . Each leg portion  36  may terminate into a turned-out portion  52 . Panel  14  may include a plurality of recess portions  40  which are convex with respect to the enclosure interior (i.e. are depressed into the enclosure interior and away from the enclosure exterior). In one embodiment, there is a recess portion  40  to correspond with each of the plurality of mounting legs  34 . Recess portion  40  includes an opening  42  which is shaped to include an enlarged opening region  44  and a residual opening region  46  (see  FIG. 2 ). In one embodiment, the motor carrier  32  also includes a plurality of spring members  48 . Spring members  48  are designed to urge motor carrier  32  away from panel  14  once the plurality of mounting legs  34  are in their fully seated position. This urging function provided by spring members  48  prevents motor carrier  32  from moving (due to the vibrational forces imparted to it during normal operation of motor  16 ) and becoming disengaged from its seated position. This feature will be discussed more fully in conjunction with  FIGS. 4A-4I . 
     In one embodiment, the height of turned-out portions  52  is less than or equal to the height of recessed portion  40 . By sizing turned-out portions  52  and recessed portions in this way, turned out portions  52  will not extend beyond the plane defined by the enclosure exterior thereby allowing one or more adjacent components (not shown) to directly abut the exterior of the enclosure. 
     Now referring to  FIGS. 4A-4F , the steps for installing the cooling fan assembly  12  of the present invention are depicted. 
     The initial positioning of the cooling fan assembly  12  against panel  14  is shown in  FIGS. 4A-4C  and is hereinafter referred to as the load position. 
     In the load position, cooling fan assembly  12  is brought adjacent panel  14  such that the turned-out portions  52  of each mounting leg  34  are inserted into a respectively associated enlarged opening region  44  of opening  42 . Each turned-out portion  52  of the resilient legs  36  is sized in relation to its associated enlarged opening  44  such that the turned-out portions  52  freely pass into enlarged opening  44  without restriction. An interior view of the load position is shown in  FIG. 4A  and an exterior view (e.g. the view as seen from the exterior of enclosure  10 ) is shown in  FIG. 4B .  FIG. 4C  shows a side view of the load position. It is important to note that in the load position, before any exertion force (designated by arrow  54 ) is applied to cooling fan assembly  12 , cooling fan assembly  12  rests against a surface of panel  14  by virtue of the contact between the bottom most bowed portion of spring member  48  and the panel  14  (see  FIG. 4C ). It is also important to note that before any exertion force is applied against cooling fan assembly  12  toward panel  14 , the turned-out end portions  52  of each resilient leg  36  do not pass completely through enlarged opening  44  of opening  42 . In the load position, because enlarged opening  44  is sized larger than the turned-out portions  52  of resilient legs  36 , no compression forces are exerted against pairs of resilient leg portions  36  and the compression gap  38  is at its maximum size. 
     Now referring to  FIGS. 4D-4F , in order to move the cooling fan assembly  12  from the load position ( FIGS. 4A-4C ) into the partially installed position ( FIGS. 4D-4F ), a combined compressive  54  and a rotating  56  force (arrows) must be imparted to at least one of the cooling fan assembly  12  or the panel  14 . The compressive force  54  acts to compress spring member  48  and move turned-out portions  52  fully into recess  40 , while the rotating force  56  repositions resilient legs  36  into an intermediate sized opening  58  of opening  42 . By comparing the length of dimension  50  between  FIG. 4C  and  FIG. 4F , it is easily seen that dimension  50  in  FIG. 4F  is much smaller than it is in  FIG. 4C . This is a depiction of the compression of spring  48 . Intermediate opening  58  is smaller than enlarged opening  44  which acts to bring together each pair of resilient leg portions  36  when rotating force  56  is exerted. Intermediate opening  58  is sized sufficiently small such that the turned-out portions  52  of each resilient leg  36  cannot pull through intermediate opening  58  under the urging of compressed spring member  48 . 
     Now referring to  FIGS. 4G-4I , as cooling fan assembly  12  is further rotated  56  from the partially installed position (as shown in  FIGS. 4D-4F ) into the fully installed position (shown in  FIGS. 4G-4I ), resilient leg portions  36  of each mounting leg  34  enter into a third portion of opening  42  called the residual opening  60 . Residual opening  60  is sized smaller than enlarged opening  44  but not as small as intermediate opening  58 . Thus, when each pair of resilient leg portions  36  transition from the intermediate opening  58  into residual opening  60 , they spring outwardly. This outward movement captures each leg portion pair  36  within its respectively associated residual opening  60 . The relative compression experienced by each pair of resilient leg portions  36  at each stage of installation can be seen by comparing the size of the compression gap  38  as the installation progresses from the load position ( FIG. 4B ) through the partially installed position ( FIG. 4E ) and, finally into the fully installed position ( FIG. 4H ). In the fully installed position, spring member  48  remains in a compressed state thereby urging turned-out portions  52  of resilient leg portions against the exterior surface of panel  14 . This urging function performed by the spring member  48  assists in preventing vibrational noise from developing between the motor carrier  32  and the panel  14  and also serves to prevent vibrational forces from causing resilient leg portions  36  from “backing out” of their respectively associated residual opening  60 . 
     Having described various embodiments of the present invention, it will be understood that various modifications or additions may be made to the preferred embodiments chosen here to illustrate the present invention without departing from the spirit of the present invention. For example, the embodiment of spring member  48  shown in the drawings is generally depicted as a compressible “bowed” member; however, any device which is capable of exerting an urging force between cooling fan assembly and panel  14  is within the contemplation of this disclosure. Accordingly, it is to be understood that the subject matter sought to be afforded protection hereby shall be deemed to extend to the subject matter defined in the appended claims (including all fair equivalents thereof).

Technology Classification (CPC): 5