Abstract:
An improved blower housing and method of manufacture comprising a wrapper wall sheet conjoined with a first side wall and a second side wall and held together with a seam interlocked with mating protrusions and apertures. The housing design may utilize different types and thicknesses of conjoined materials and reuse the components when separated. Unlike prior art blower housing seams, the present art provides a substantially smooth positive locking seam without the use of welds or fasteners.

Description:
[0001]    This application claims priority of U.S. Provisional Patent Application No. 60/627,805, filed Nov. 15, 2004. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The art of the present invention relates to blower housings for blower fan assemblies used in HVAC systems although the present invention can also be utilized in other industries employing blower systems. The improved blower housing of the present invention incorporates a uniquely formed joint or seam having a combination locking tab and slot which provides positive lockup of the blower housing side walls to a blower housing wrapper wall sheet. The present art essentially eliminates unintentional separation of the formed unit both prior to final manufacturing assembly and during its entire useful service life. 
         [0003]    Blower housings of the type pertaining to the present invention are typically employed in forced air heating furnaces or air conditioners. In most cases, the blower is assembled in the interior of the HVAC equipment. Ambient air is blown by the blower over heat exchangers that heat or cool the air. The heated or cooled air is then forced from the furnace/air conditioner by the blower. A typical blower housing contains a cylindrical blower fan and is constructed from a pair of housing side walls spaced at opposite lateral sides of the blower housing and a wrapper wall sheet that is connected around peripheral edges of the two side walls. The wrapper wall sheet spaces the two side walls laterally from each other and gives the blower housing a general cylindrical configuration well suited for containing the cylindrical blower fan. 
         [0004]    With the commercially manufactured prior art, the side walls and the wrapper wall sheet of a conventional non-welded blower housing assembly are typically either attached by a crimped folded over seam joint or, as in the case of applicant&#39;s prior U.S. Pat. No. 5,221,183, a two-sectional angled seam joint. Both of the prior art attachment types, use seams which are now known to function as an essential slip-joint allowing movement and/or separation of the assembly&#39;s side walls and wrapper wall sheet. This movement and/or separation problem is particularly apparent during final assembly of the complete blower unit. (i.e. motor and blower fan installation) When separated, the side walls and the wrapper wall sheet are no longer usable thereby causing significant operating and yield loss (e.g. scrap) during the manufacturing or repair process. Prior art blower housings attempt to address the blower housing separation problem by utilizing either spot welds and/or auxiliary fasteners, such as end screws, neither of which is satisfactory since both increase the manufacturing cost of the blower housing. 
         [0005]    The combination locking tab and slot seam of Applicant&#39;s improved blower housing allows for the joining of different materials and/or different material thicknesses. The seam versatility of the present invention, which is adaptable to material variations, can provide significant engineering advantages such as thicker material utilization on the load bearing side wall (which typically supports the motor and wheel assembly) and thinner material utilization on the non-load bearing side wall and the wrapper wall sheet. Also, a greater size range of blower housings can be manufactured in the same assembly machines with less cycle time and without changeover or modification to the equipment, thereby reducing the manufacturing cost of the blower housings. The ability to join the blower housing dissimilar material or material of varying thickness is desired since the assembly machine can be built easier and less expensively. Accordingly, one assembly or forming machine can be programmed to not only make a larger size range of blower housings but also to produce the blower housings faster and therefore less expensively. 
         [0006]    The combination locking tab and slot seam of the present invention further provides that the locking tab is substantially flush with the outside surface of the wrapper wall sheet when finally engaged in the slot regardless of orientation or material variation. This ensures a substantially smooth seam throughout its entire formed length. 
         [0007]    Accordingly, it is an object of the present invention to provide an improved blower housing and method of manufacture which provides a positive lockup of blower side walls to a blower housing without the use of welds or fasteners. 
         [0008]    Another object of the present invention is to provide an improved blower housing and method of manufacture which is environmentally friendly by allowing reuse of the blower side walls and wall sheet when separated without the necessity of discarding said components. 
         [0009]    A further object of the present invention is to provide an improved blower housing and method of manufacture which is capable of joining different materials and materials of different thicknesses. 
         [0010]    A still further object of the present invention is to provide an improved blower housing and method of manufacture which is easy and economical to manufacture in a variety of sizes with the same assembly machines. 
         [0011]    A yet further object of the present invention is to provide an improved blower housing and method of manufacture having locking tabs mating with slots which are substantially flush with the outside surface of the wrapper wall sheet regardless of orientation or material variation in order to provide a substantially smooth seam. 
       SUMMARY OF THE INVENTION 
       [0012]    The art of the present invention comprises a new and improved blower housing utilizing a unique joint or seam for attaching both side walls to a wrapper wall sheet. The improved blower housing comprises a first side wall, a second side wall opposite the first side wall, and a wrapper wall sheet attached intermediate the first side wall and the second side wall. The present art prohibits slippage in the seams or joints between the side walls and wrapper wall which is especially useful during manufacturing with worn or out of adjustment forming machines. It further allows use of spring loaded forming rollers within the forming machine whereby a wide range of materials (including thicknesses) may be utilized. 
         [0013]    The wrapper wall sheet has a first lateral edge flange and a second lateral end flange opposite the first lateral edge flange. The lateral edge flanges comprise inner portions and outer portions having one or more apertures. The side walls have an inner surface, an outer surface, and a circumferential edge with an edge margin having one or more protrusions. The one or more protrusions protrude from the surface of the side walls. The one or more apertures of the wrapper wall sheet are capable of receiving the one or more protrusions of the side walls. This provides wrapper wall sheet lateral edge flange attachment to the edge margins of the circumferential edges of the side walls by a formed joint or seam. 
         [0014]    The formed joint or seam comprises the combination of the one or more protrusions of the edge margin of the side walls received within the one or more apertures of the lateral edge flanges of the wrapper wall sheet. Thus, when the lateral edge flanges of the wrapper wall sheet are formed or pressed against the edge margins of the side walls, the one or more protrusions are substantially locked within the one or more apertures. 
         [0015]    The improved blower housing is typically manufactured from sheet metal, preferably sheet metal which is either inherently corrosion resistant or coated to provide corrosion resistant properties. Typical sheet metals include but are not limited to stainless steel, aluminum, and coated steel products, such as pre-painted steel, galvanized steel, galvalume® steel, or other aluminized steels. The sheet metal would typically have a thickness range of 16-26 gauge, as conventionally measured within the sheet metal industry. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Numerous other objects, features and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0017]      FIG. 1  is a perspective view of the preferred embodiment of the improved blower housing. 
           [0018]      FIG. 2  is a detailed perspective view of the preferred embodiment taken along line  2  of  FIG. 1 . 
           [0019]      FIG. 3  is a detailed perspective view of the preferred embodiment taken along line  3  of  FIG. 1 . 
           [0020]      FIG. 4  is a detailed perspective view of the preferred embodiment taken along line  4  of  FIG. 1 . 
           [0021]      FIG. 5  is a perspective unassembled view of the preferred embodiment. 
           [0022]      FIG. 5   a  is another perspective unassembled view of the preferred embodiment. 
           [0023]      FIG. 6  is a top plan unassembled view of the preferred embodiment. 
           [0024]      FIG. 7  is a left side unassembled view of the preferred embodiment. 
           [0025]      FIG. 7   a  is a detailed side view of the preferred embodiment taken along line  7   a  of  FIG. 7  further illustrating the one or more first apertures of the wrapper wall sheet. 
           [0026]      FIG. 7   b  is a detailed side view of the preferred embodiment taken along line  7   b  of  FIG. 7  further illustrating the one or more first protrusions of the first side wall. 
           [0027]      FIG. 7   c  is a right side unassembled view of the preferred embodiment. 
           [0028]      FIG. 7   d  is a detail right side view of the preferred embodiment taken along line  7   d  of  FIG. 7   c  further illustrating the one or more second apertures of the wrapper wall sheet. 
           [0029]      FIG. 7   e  is a detail right side view of the preferred embodiment taken along line  7   e  of  FIG. 7   c  further illustrating the one or more second protrusions of the second side wall. 
           [0030]      FIG. 8  is a cross sectional view of the preferred embodiment of the un-locked seam prior to forming taken along line  8  of  FIG. 5  and further illustrating the one or more first apertures and the first lateral edge of the wrapper wall sheet, and the one or more first protrusions of the first side wall. 
           [0031]      FIG. 8   a  is another cross sectional view of the preferred embodiment of the un-locked seam prior to forming taken along line  8   a  of  FIG. 5   a  and further illustrating the one or more second apertures and the second lateral edge of the wrapper wall sheet, and the one or more second protrusions of the second side wall. 
           [0032]      FIG. 9  is a top assembled view of the preferred embodiment. 
           [0033]      FIG. 10  is a cross sectional view of the preferred embodiment of the locked seam after forming taken along line  10  of  FIG. 9 . 
           [0034]      FIG. 10   a  is another cross sectional view of the preferred embodiment of the locked seam after forming taken along line  10   a  of  FIG. 9 . 
           [0035]      FIG. 11  is a perspective view of an alternate embodiment of the improved blower housing. 
           [0036]      FIG. 12  is a detail perspective view of the alternate embodiment taken along line  12  of  FIG. 11 . 
           [0037]      FIG. 12   a  is a detail perspective view of the alternate embodiment taken along line  12   a  of  FIG. 11 . 
           [0038]      FIG. 13  is a cross sectional view of the alternate embodiment of the locked seam after forming and taken along line  13  of  FIG. 12 . 
           [0039]      FIG. 13   a  is another cross sectional view of the alternate embodiment of the locked seam after forming taken along line  13   a  of  FIG. 12   a.    
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Referring now to the drawings, there is shown in  FIGS. 1-10   a  a preferred embodiment and in  FIGS. 11-13   a  alternate embodiments of the improved blower housing and method of manufacture  10 . The improved blower housing  10 ,  12  comprises a first side wall  16 , a second side wall  32  (collectively sidewalls  14 ) opposite the first side wall  16 , and a wrapper wall sheet  52  attached intermediate the first side wall  16  and the second side wall  32 . 
         [0041]    In a preferred embodiment, the wrapper wall sheet  52  has a first lateral edge flange  54  and a second lateral end flange  64  opposite the first lateral edge flange  54 . The first lateral edge flange  54  comprises a first inner portion  56  and a first outer portion  58  having one or more first apertures  60  and the opposite second lateral edge flange  64  comprises a second inner portion  66  and a second outer portion  68  having one or more second apertures  70 . The first side wall  16  has a first inner surface  18 , a first outer surface  20 , and a first circumferential edge  22  with a first edge margin  24  having one or more first protrusions  26 . The opposite second side wall  32  has a second inner surface  34 , a second outer surface  36 , and a second circumferential edge  38  with a second edge margin  40  having one or more second protrusions  42 . The one or more first protrusions  26  protrude from the first outer surface  20  of the first side wall  16  and the one or more second protrusions  42  protrude from the second outer surface  36  of the second side wall  32 . The one or more first apertures  60  of the wrapper wall sheet  52  are capable of receiving the one or more first protrusions  26  of the first side wall  16  and the one or more second apertures  70  of the wrapper wall sheet  52  are capable of receiving the one or more second protrusions  42  of the second side wall  32 . This allows the first lateral edge flange  54  of the wrapper wall sheet  52  to attach with the first edge margin  24  of the first circumferential edge  22  of the first side wall  16  and the second lateral edge flange  64  of the wrapper wall sheet  52  to attach with the second edge margin  40  of the second circumferential edge  38  of the second side wall  32  by a formed joint or seam  74 . 
         [0042]    The formed joint or seam  74  comprises the combination of the one or more first protrusions  26  of the first edge margin  24  of the first side wall  16  received within the one or more first apertures  60  of the first lateral edge flange  54  of the wrapper wall sheet  52 . The one or more second protrusions  42  of the second edge margin  40  of the second side wall  32  are received within the one or more second apertures  70  of the second lateral edge flange  64  of the wrapper wall sheet  52  also to form a joint or seam  74 . Thus, when the first lateral edge flange  54  of the wrapper wall sheet  52  is formed or pressed against the first edge margin  24  of the first side wall  16  and the second lateral edge flange  64  of the wrapper wall sheet  52  is formed or pressed against the second edge margin  40  of the second side wall  32 , the one or more first protrusions  26  are substantially locked within the one or more first apertures  60  and the one or more second protrusions  42  are substantially locked within the one or more second apertures  70 . 
         [0043]    In a preferred embodiment, the one or more first apertures  60  further comprise one or more first elongated apertures or slots and the one or more second apertures  70  further comprise one or more second elongated apertures or slots. In a preferred embodiment, the elongated apertures or slots  60 ,  70  are approximately ⅜ inches long and approximately ⅛ inches wide. In this embodiment, prior to attaching the wrapper wall sheet  52  to the first and second side walls  16 ,  32 , both the first outer portion  58  of the first lateral edge flange  54  of the wrapper wall sheet  52  and the second outer portion  68  of the second lateral edge flange  64  of the wrapper wall sheet  52  are preferably formed at an approximate 30° angle to a vertical axis. In a preferred embodiment, both the first inner portion  56  of the first lateral edge flange  54  and the second inner portion  66  of the second lateral edge flange  64  are substantially vertical or at an approximate 0° angle relative to the vertical axis. Alternative embodiments may utilize any angle which allows the flanges  54 ,  64  to function as described herein. The size and quantity of the apertures  60 ,  70  and protrusions  26 ,  42  forming the locking tab  28 ,  44  and slot  60 ,  70  of the seam  74  is product driven and dictated by the size and type of blower housing  12 . 
         [0044]    Also in the preferred embodiment, the one or more first protrusions  26  further comprise one or more first tabs  28 ; and the one or more second protrusions  26  further comprise one or more second tabs  44 . Both the one or more first tabs  28  and the one or more second tabs  44  are preferably formed by punching one or more substantially U-shaped members  30  along both the first and the second edge margins  24 ,  40  and bending (i.e. bent tab) the one or more substantially U-shaped members  30  outward such that one or more first protrusions  26  or first tabs  28  and the one or more second protrusions  42  or second tabs  44  are formed and protruding from the first outer surface  20  and the second outer surface  36 , respectfully. In this embodiment, prior to attaching the wrapper wall sheet  52  to the first and second side walls  16 ,  32 , both the one or more first tabs  28  and the one or more second tabs  44  are preferably formed such that they are protruding outward at an approximate 45° degree angle from a vertical axis. Alternative embodiments may utilize any angle which allows the tabs  28 ,  44  to function as described herein. 
         [0045]    The one or more first tabs  28  and the one or more second tabs  44  are respectively formed and spaced along the first edge margin  24  and second edge margin  40  such that the one or more first tabs  28  are capable of being received within the one or more first slots  60  and the one or more second tabs  44  are capable of being received within the one or more second slots  70 . In a preferred embodiment, when received, said tabs  28 ,  44  or protrusions  26 ,  42  forcibly engage or contact a wall of said slots or apertures  60 ,  70 . That is, if preferred tolerances are maintained when assembled, a portion of the each protrusion  26 ,  42  contacts a portion of the aperture  60 ,  70  wall within which it is received or mated. 
         [0046]    In an alternate embodiment of the improved blower housing  10 , the first lateral edge flange  54  of the wrapper wall sheet  52  further comprises a first outer portion  58  and a first inner portion  58  having one or more first apertures  60 , and the opposite second lateral edge flange  64  further comprises a second outer portion  68  and a second inner portion  66  having one or more second apertures  70 . Also in the alternate embodiment, the one or more first protrusions  26  protrude from the first inner surface  18  of the first side wall  16  and the one or more second protrusions  42  protrude from the second inner surface  34  of the second side wall  32 . That is, the location of the apertures  60 ,  70  are in the inner portion  56 ,  66  of the wrapper wall sheet  52  flanges  54 ,  64  and the location of the protrusions  26 ,  42  are on the inner surfaces  18 ,  34  of the side walls  14 , as opposed to in the outer portion  58 ,  68  of the flanges  54 ,  64  and the outer surfaces  20 ,  36  of the side walls  16 ,  32  as in the preferred embodiment. This locates the combination locking tab  28 ,  44  and slot  60 ,  70  of the seam  74  on the first inner surface  18  of the first side wall  14  and the second inner surface  34  of the second side wall  32  of the improved blower housing  10 ,  12 . Said tabs  28 ,  44  and slots  60 ,  70  are thereby less visible on the improved blower housing  10 ,  12  assembly versus the preferred embodiment where said tabs  28 ,  44  and slots  60 ,  70  are located on the outer surfaces  20 ,  36  of the side walls. 
         [0047]    In other alternative embodiments, the first side wall edge  22  further comprises a first edge margin  24  having one or more first apertures  60 ; and a second side wall edge  38  further comprises a second edge margin  40  having one or more second apertures  70 . The wrapper wall sheet  52  further comprises a first lateral edge flange  54  having one or more first protrusions  26 ; and a second lateral edge flange  64  having one or more second protrusions  42 . Both the one or more first protrusions  26  and the one or more second protrusions  42  are capable of formation in either an inner portion  56 ,  66  or an outer portion  58 ,  68  of the lateral edge  54 ,  64  thereby effecting whether the combination locking tab  28 ,  44  and slot  60 ,  70  of the seam  74  is located on either an outer portion  58 ,  68  or outer surface  20 ,  36  or an inner portion  56 ,  66  or inner surface  18 ,  34  as in other embodiments of the improved blower housing  10 ,  12 . 
         [0048]    The improved blower housing  10  is manufactured by forming and providing a first side wall  16 , a second side wall  32  opposite the first side wall  16 , and a wrapper wall sheet  52  attached intermediate the first side wall  16  and the second side wall  32 . The wrapper wall sheet  52  is preferably first formed by punching or forming the one or more first apertures  60  along the first lateral edge flange  54  and punching or forming the one or more second apertures  70  along the second lateral edge flange  64 . Second, the first lateral edge flange  54  is bent into a substantially J-shaped first member and the second lateral edge flange  64  is bent into a substantially J-shaped second member such that the substantially J-shaped first member has the first inner portion  56  and the first outer portion  58  and the substantially J-shaped second member has the second inner portion  66  and the second outer portion  68 . Both of the one or more first apertures  60  are punched on the first lateral edge flange  54  and the one or more second apertures  70  are punched on the second lateral edge flange  64  and positioned such that they are within the first outer portion  58  and the second outer portion  68 , respectively. Alternative embodiments may utilize methods such as laser, water jet, or torch cutting to form said apertures  60 ,  70  in lieu of punching. 
         [0049]    The first and second side walls  14 ,  32  are preferably formed by forming and punching one or more substantially U-shaped members  30  along both the first and the second edge margins  24 ,  40  and bending the one or more substantially U-shaped members  30  outward such that the one or more first protrusions  26  or first tabs  28  and the one or more second protrusions  42  or second tabs  44  are formed and protruding from the first outer surface  20  and the second outer surface  36 , respectfully. 
         [0050]    The wrapper wall sheet  52  is then positioned and held intermediate the first side wall  16  and the opposite second side wall  32  such that the one or more first protrusions  26  of the first edge margin  24  of the first side wall  16  are received within the one or more first apertures  60  of the first lateral edge flange  54  of the wrapper wall sheet  52  and the one or more second protrusions  42  of the second edge margin  40  of the second side wall  32  are received within the one or more second apertures  70  of the second lateral edge flange  64  of the wrapper wall sheet  52 . The first lateral edge flange  54  of the wrapper wall sheet  52  is then formed or pressed against the first edge margin  24  of the first side wall  16  and the second lateral edge flange  64  of the wrapper wall sheet  52  is formed or pressed against the second edge margin  40  of the second side wall  32 . Typically, right and left forming rollers adapted to engage with the flange  54 ,  64  rotationally press the outer portion  58 ,  68  onto and with said edge margin  24 ,  40 . Other methods understood within the art may be utilized to perform the aforesaid pressing operation. 
         [0051]    After forming both the first lateral edge flange  54  and the second lateral edge flange  64 , the one or more first protrusions  26  are substantially locked within the one or more first apertures  60 , and the one or more second protrusions  42  are substantially locked within the one or more second apertures  70  and essentially non-separable. The substantial lockup provides three-axial locking thereby providing greater stability and minimal slippage in a forming machine. That is, the wrapper wall sheet  52  is substantially locked to the first side wall  16  and the second side wall  32  after just starting to form the first and second lateral edges  54 ,  64  with only one first protrusion  26  received within one first aperture  60  and/or one second protrusion  42  received within one second aperture  70 . 
         [0052]    Within the aforesaid first alternate embodiments, the wrapper wall sheet  52  has both the one or more first apertures  60  punched on the first lateral edge flange  54 , the one or more second apertures  70  punched on the second lateral edge flange  64 , and each are positioned such that they are within the first inner portion  56  and the second inner portion  66 , respectively. The first and second side walls  16 ,  32  are preferably formed by punching one or more substantially U-shaped members  30  along both the first and the second edge margins  24 ,  40 , bending the one or more substantially U-shaped members  30  inward such that one or more first protrusions  26  or first tabs  28  and the one or more second protrusions  42  or second tabs  44  are formed and protruding from the first inner surface  18  and the second inner surface  34  respectfully. Further alternate embodiments may utilize protrusions  26 ,  42  which are simply drawn from or which are attached with the edge margins  24 ,  40 . Assembly proceeds as with the preferred embodiment. 
         [0053]    Within another alternate embodiment, the wrapper wall sheet  52  is alternatively formed by forming or punching one or more substantially U-shaped members  30  along both the first and the second lateral edge flanges  54 ,  64  and bending both the one or more substantially U-shaped members  30  outward such that one or more first protrusions  26  or tabs  28  and the one or more second protrusions  42  or tabs  44  are formed and protruding from the first outer portion  58  and the second outer portion  68  respectfully. The first and second side walls  16 ,  32  are preferably formed by forming or punching one or more first apertures  60  along the first edge margin  24  and punching one or more second apertures  70  along the second edge margin  40 . The wrapper wall sheet  52  is positioned and held intermediate the first side wall  16  and the opposite second side  32  wall such that the one or more first protrusions  26  of the first lateral edge  54  are received within the one or more first apertures  60  of the first edge margin  24  of the first side wall  16  and the one or more second protrusions  42  of the second lateral edge  64  are received within the one or more second apertures  70  of the second edge margin  40  of the second side wall  32 . The first lateral edge  54  of the wrapper wall sheet  52  is formed or pressed against the first edge margin  24  of the first side wall  16  and the second lateral edge  64  of the wrapper wall sheet  52  is formed or pressed against the second edge margin  40  of the second side wall  32 . Again, typically right and left forming rollers adapted to engage with the flange  54 ,  64  rotationally press the outer portion  58 ,  68  onto and with said edge margin  24 ,  40 . After forming both the first lateral edge  54  and the second lateral edge  64 , the one or more first protrusions  26  are substantially locked within the one or more first apertures  60 , and the one or more second protrusions  42  are substantially locked within the one or more second apertures  70  and are essentially non-separable. 
         [0054]    Further alternate embodiments encompass the one or more substantially U-shaped members  30  along both the first and the second lateral edge flanges  54 ,  64 . The members  30  are bent inward such that the one or more first tabs  28  and the one or more second tabs  44  are formed and protruding from the first inner portion  56  and the second inner portion  66 , respectfully. Again, assembly proceeds as with the preferred embodiment. 
         [0055]    From the foregoing description, those skilled in the art will appreciate that an improved blower housing and method of manufacture  10  has been shown and described. The art is easy and cost effective to manufacture and repair, and further provides positive blower housing  12  component  14 ,  52  locking without slippage and without the use of spot welds or other types of fasteners. 
         [0056]    Having described the invention in detail, those skilled in the art will appreciate that all the objects of the present invention are realized and that modifications may be made to the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.