Patent Publication Number: US-2016245324-A1

Title: Appliance fastening apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/890,655, filed on Oct. 14, 2013, which is incorporated by reference herein. 
    
    
     BACKGROUND AND SUMMARY 
     The present invention relates generally to appliance fastening apparatuses and more particularly to a fastener attached to a hole in an appliance. 
     It is common to employ many sheet metal anchor nuts to secure screws extending through a hole within an internal liner of a refrigerator appliance. These screws are typically used to attach shelf mounting brackets within the liner. Examples of such anchoring devices are disclosed in U.S. Pat. No. 4,647,263 entitled “Nut Plate Fastener” which issued to Macfee, Jr. et al. on Mar. 3, 1987; U.S. Pat. No. 4,325,178 entitled “Screw Anchoring Device and Method” which issued to Pruehs on Apr. 20, 1982; and U.S. Pat. No. 3,802,476 entitled “Screw Anchor” which issued to Hoadley on Apr. 9, 1974, all of which are incorporated by reference herein. 
     In commercial practice, the most common type are those like the &#39;178 Pruehs patent, however, a double-sided, pressure sensitive adhesive tape is required between the flat portion of the fastener and an exterior surface of the liner. This extra adhesive tape is intended to both seal the liner hole against insulating foam leakage and to also supplementally secure the fastener to the liner while the foam is injected into the appliance between the liner and an outer metallic shell. Nevertheless, in practice, the foam injection still disengages and displaces one or more of the many fasteners which then necessitates scrapping the entire appliance since it is cost prohibitive to rectify the internal fastener placement after the foam has been injected. In an effort to overcome this problem, an operator is often forced to manually apply a second layer of adhesive tape external to the fastener to supplementally hold it against the liner prior to foam injection. Needless to say, placement of a single adhesive tape layer, let alone two, for each of many screw anchoring fasteners is very labor intensive and expensive, yet is still prone to displacement concerns when the foam is injected. Furthermore, a reduction in foam leakage is desired in order to reduce manual rework and aesthetic concerns inside the liner. 
     In accordance with the present invention, an appliance fastening apparatus is provided. In another aspect, a polymeric fastener includes an anti-rotational formation or surface. Another aspect of the appliance fastening apparatus includes a polymeric section essentially encapsulating a metallic nut therein. In yet another aspect, flexible polymeric barbed legs extend through a hole in an appliance wall such that wedge-shaped or barbed sections thereof are essentially on an opposite surface of the appliance wall from a polymeric head and/or metallic nut coupled thereto. A further aspect employs a flexible and polymeric umbrella to assist in deterring insulating material from leaking through an appliance hole. A method of using and/or manufacturing a polymeric appliance fastener is also provided. 
     The present appliance fastening apparatus is advantageous over traditional devices. For example, the present fastener will not be dislocated or removed during foam insertion. Furthermore, the present fastener deters foam leakage through the appliance hole without requiring adhesive tape. Moreover, the present apparatus is advantageously useful for a hole in an appliance interior liner, such as to secure shelf bracketry, and is also usable for a hole in an exterior shell of the appliance such as to secure a leveling or anti-tipping foot. Additional advantages and features of the present invention will become apparent from the following description and associated claims, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an appliance including multiples of the present appliance fastening apparatus; 
         FIG. 2  is an interior perspective view, taken within circle  2  of  FIG. 1 , showing the present appliance fastening apparatus; 
         FIG. 3  is a cross-sectional view, taken along line  3 - 3  of  FIG. 2 , showing the present appliance fastening apparatus; 
         FIG. 4  is an exterior perspective view, taken generally opposite that of  FIG. 2 , showing the present appliance fastening apparatus; 
         FIG. 5  is a perspective view showing a nut employed in the present appliance fastening apparatus; 
         FIG. 6  is an exterior elevational view, taken generally in the direction of  FIG. 4 , showing the present nut; 
         FIG. 7  is a side elevational view showing the present nut; 
         FIG. 8  is a side elevational view, taken opposite that of  FIG. 7 , showing the present nut; 
         FIG. 9  is a cross-sectional view, taken along line  9 - 9  of  FIG. 6 , showing the present nut; 
         FIG. 10  is a perspective view, taken generally in the same direction as  FIG. 2 , showing a preferred fastener employed in the present appliance fastening apparatus; 
         FIG. 11  is a perspective view, generally taken in the direction of  FIG. 4 , showing the present fastener; 
         FIG. 12  is a cross-sectional view, taken along line  12 - 12  of  FIG. 11 , showing the present fastener; 
         FIG. 13  is a cross-sectional view, taken along line  3 - 3  of  FIG. 2 , showing the present appliance fastening apparatus prior to insertion of a threaded screw; 
         FIG. 14  is a perspective view showing an alternate embodiment fastener employed with the present appliance fastening apparatus; 
         FIG. 15  is a perspective view, taken generally opposite that of  FIG. 14 , showing the alternate embodiment fastener; and 
         FIG. 16  is a cross-sectional view, taken along line  16 - 16  of  FIG. 1 , showing the present appliance fastening apparatus used with a leg leveler. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-4 and 10-13 , the appliance fastening apparatus  21  of the present invention includes an appliance  23 , also known as a white good, a fastener  25  and a threaded screw  27 , which includes an elongated shaft and can alternately be a bolt. Screw  27  retains a bracket  29  supporting a moveable internal appliance shelf  31 , ice maker or water dispenser  33 , door shelves  35 , exterior handles  37 , hinges  39  or foot levelers  41 . The preferred appliance  23  is a refrigerator or freezer, as shown, but may alternately include a stove and oven appliance, a dishwasher appliance, a clothes washing machine appliance, a clothes dryer appliance, or the like. Fasteners and foot levelers of such alternate appliances may be replaced by those of the present disclosure, and are shown in the following U.S. Pat. No. 7,959,742 entitled “Outer Support Body for a Drawer-Type Dishwasher” which issued to Cordill et al. on Jun. 14, 2011; U.S. Pat. No. 6,533,238 entitled “Versatile Anti-Tip Bracket for an Appliance” which issued to Barnes et al. on Mar. 18, 2003; and U.S. Pat. No. 4,890,813 entitled “Anti-Tip Bracket for Ranges” which issued to Johnson et al. on Jan. 2, 1990; all of which are incorporated by reference herein. 
     The preferred refrigerator and freezer appliance  23  further include a structural, outer metallic shell or wall  51  and an interior liner or wall  53  which is a structural, thermo-formed or vacuum formed polymeric member. A hole  55  (see  FIGS. 3 and 13 ), is punched through inner or outer walls,  53  and  51  respectively, in multiple locations depending upon where through fasteners are desired. After fastener  25  has been attached to hole  55  in the interior or exterior walls, and the inner liner  53  has been assembled to shell  51 , an insulating material, such as a liquid and expandable polyurethane foam  61  is injected or poured between the inner and outer walls and in contact with the exposed portions of fastener  25 . 
     Referring now to  FIGS. 10-13 , fastener  25  is entirely injection molded from a polymeric material, such as polypropylene or ABS, but for a metallic nut  71 . Fastener  25  includes a generally circular-cylindrical head  73 , barbed legs  75  and a flexible and frusto-conically shaped umbrella  77 , all integrally made as a single piece from the polymeric material. Head  73  includes at least two and more preferably four recessed cavities  81  which radially project away from a centerline of the fastener co-axially aligned with hole  55 . The injected foam  61  engages and contacts within recessed cavities  81  and the upstanding surface formations defining such, thereby serving as anti-rotational features after the foam cures. Screw  27  is inserted into the nut as will be later discussed. Passageways  83  are also located in an otherwise generally flat surface  85  of head in a generally parallel direction to the centerline of the part. These passageways  83  provide access for locating pins to support nut  71  during the insert molding process used to create the polymeric portions of fastener  25  encapsulating the nut. A partial passageway  89  is located within head  73  aligned with centerline. Additional passageways  91  are also positioned in the under surface of head  85  to allow molding pin support for nut  71 . Additionally, ribs  93  project from the under surface of head  73  to deter over compression of umbrella  77  during insertion of leg  75  into the appliance hole  55 , during foam injection, and/or during over-torquing of threaded screw  27 . 
     Each polymeric leg  75  includes a medial stem section  101  and a wedge shaped or barbed end section  103  having internal and external tapers on tips thereof. The external and laterally facing surfaces (i.e., opposite a hollow bore  111 ) of each leg has an arcuate shape such that when the legs are all compressed together toward the centerline, they generally define circular cross-sections along the length thereof. Each leg  75  is spaced apart from its adjacent neighbors in a partially severed manner by slotted openings  107  having terminal points of which are preferably slighting spaced away from the underside surface of head  73  depending upon the leg flexure and stiffness desired. The triangular point  109  of each barbed section extends completely through hole  55  in the appliance wall such that point  109  is on an opposite surface of the wall from umbrella  77  and head  73 . 
     A generally cylindrical, hollow bore  111  projects within legs  75  coaxial with the centerline. This bore  111  preferably terminates in a generally conical end  113  internal to head  73  and aligned with a centerline of an aperture  117  of nut  71 . The very thin distance between the end of bore  111  and the bottom of partial passageway  89  is little more than molding flash which defines a bridging segment  119  spanning across aperture  117  of nut  71 . Bridging segment  119  assists in sealing the fastener to deter foam from leaking through the appliance hole  55 . Bridging segment  119  is frangible or breakable upon piercing insertion of threaded screw  27 . It is preferred that threaded screw  27  have a flat or rounded distal end such that it need not be a self-piercing screw, however, a self-piercing screw can alternately be employed. At least one flexible barbed leg is employed, more preferably at least three such legs are used, and it is most preferable to use six equilaterally spaced apart legs, especially if a circular hole is employed in the appliance wall. 
     Nut  71  is best illustrated in  FIGS. 5-9 . Nut  71  is preferably stamped from carbon mild, spring or stainless steel having a Rockwell hardness of approximately  30  newtons. It is designed as a lock nut having a generally flat and uniformly dimensioned body  131  and a central raised dome area defining a single thread internal edge  133  creating a generally spirally circular part of its aperture  117 . A single slot  135  is also cut from one side of aperture  117  to allow for flexed expansion of thread  133  during threaded screw engagement. Openings  137  are also provided in body  131  to allow for polymeric flow through during the insert molding to maintain a better engagement between the polymeric head and metallic nut of the fastener. Additionally, a periphery  139  of nut is generally polygonal, and more preferably square, with essentially flat edge surfaces to further minimize rotation of the nut relative to the polymeric head during screw insertion. 
       FIGS. 2 through 4 and 13  show fastener  25  manually attached to wall  53  of appliance. In this condition, legs  75  of fastener  25  are snap-fit inserted through hole  55 . Foam  61  is injected thereagainst whereby flexed umbrella  77  and bridging segment  119  act to seal foam  61  from leaking through hole  55 . Thereafter, threaded screw  27  is manually screwed into engagement within hollow channel  111  and then with the internally threaded aperture  117  of nut  71  as it pierces through the bridging segment of polymeric material spanning thereacross. The distal end of threaded screw  27  continues to extend through partial passageway  89  and then into foam  61 . 
     An alternate configuration of fastener  225  is illustrated in  FIGS. 14 and 15 . This construction is identical with the prior fastener, however, a head  275  has radially and laterally projecting wall formations  281  thereon instead of recessed cavities as in the prior embodiment. The only other noteworthy difference in the fastener embodiments is that the present fastener  225  also has a generally oval shaped head and umbrella periphery instead of the prior circular shape. It may alternately be defined as a substantially elliptical-cylindrical periphery. It should be appreciated that the anti-rotational features  81  (see  FIG. 11 ) or  281  (see  FIG. 14 ) can be interchanged between each other and/or added to the other. 
       FIG. 16  illustrates the same fastener  325  of either of the prior embodiments. In this configuration, however, a threaded shaft  327  constitutes a leg leveler wherein a foot  329  contacts a floor  331  such that location of leg leveler  327  relative to fastener  325  adjusts the height of the appliance relative to the floor. 
     While various embodiments of the present invention have been disclosed, it should be appreciated that other variations may be employed. For example, while a stamped sheet metal nut is disclosed, it should alternately be clear that a cast, machined, sintered, or even injection molded polymeric nut may be used, although the present cost and strength benefits may not be obtained. Furthermore, additional polymeric sections may be constructed between the legs, umbrella, head and anti-rotational surfaces, and/or appended thereto, although some of the present cost and packaging benefits may not be realized. Additionally, the presently disclosed arcuate leg, umbrella, and head peripheries may be substituted with one or more straight surfaces, especially if the appliance hole shape is rectangular, however, certain advantages may not be realized. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.