Patent Publication Number: US-2006005363-A1

Title: Grommet snap fastening device

Description:
FIELD OF THE INVENTION  
      The present invention is generally directed to a novel fastening device for fastening leather, fabrics, and sheet-like materials. In particular, the present invention relates to a grommet snap fastening device for fastening leather, fabrics, and sheet-like materials which allows for convenient and simple operation, verification of secure engagement by sight, and which is suitable for use in various consumer products.  
     BACKGROUND OF THE INVENTION  
      Many devices have been proposed for fastening leather, fabrics, and sheet-like materials. One widely-used device is a snap fastener that includes a male element and a female component each attached to materials desired to be fastened together by joining the male and female components. The snap fasteners may be mechanical or magnetic. Mechanical snap fasteners have an interference fit between the male and female components. Magnetic snap fasteners use magnetic force to engage the male and female components.  
      Existing snap fasteners may incorporate a flexible ring which is secured to the female element and which fits around the male component to secure the fastener. Traditionally, such a flexible ring is secured within the female component of the fastener by crimping or bending the female component to form a socket, or by incorporation of the ring into the female component. Additionally, the traditional snap fastener configurations described above do not allow for verification of secure engagement of the male and female components by sight.  
      There remains a need for fastening devices which allow for convenient operation, ease of construction and assembly, verification of secure engagement, and which have suitable safety, ergonomic, and aesthetic properties for incorporation into various consumer applications.  
     SUMMARY OF THE INVENTION  
      The present invention is directed to a novel fastening device comprising a male component including a first or upper male element secured to a second or lower male element, and a female component including a first or upper female element secured to a second or lower female element. A flexible annular compression ring having spring properties is located between the upper and lower female elements. A first sheet of material is located between the upper and lower elements of the male component, and a second sheet of material is located between the upper and lower elements of the female component. A groove is located upon the upper male element. The male component is detachably secured within the female component by engagement of the flexible compression ring with the groove. The terms “upper” and “lower” are, of course, merely relative positions.  
      The lower male element and the upper male element may be joined by an interference fit between a shaft of the lower male element and a hole of the upper male element, or may screw together, and the lower female element and the upper female element may optionally be joined by an interference fit between a body of the lower female element and a hole in the upper female element, or may screw together.  
      The female component may include an aperture to permit sight of the male component upon engagement of the flexible compression ring with the groove, and the female component may include a ridge formed on an outer periphery for securing the second material.  
      The present invention is further directed to a method of detachably securing two sheets of material using a fastener, comprising the steps of joining a lower male element and an upper male element to form a male component, and joining a lower female element and an upper female element to form a female component. A first sheet of material is located between the lower male element and the upper male element, and a second sheet of material is located between the lower female element and the upper female element. A compression ring is located between the lower and upper female elements and a groove is located on the upper male element.  
      The lower male element and the upper male element may be joined by an interference fit between a shaft of the lower male element and a hole of the upper male element, and the lower female element and the upper female element may be joined by an interference fit between a body of the lower female element and a hole in the upper female element. The male component is extended into the female component until the male and female components engage at the compression ring and the groove. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a cross-sectional view of an embodiment of the invention in an assembled state.  
       FIG. 2  is a cross-sectional view of the female component of the invention.  
       FIG. 3  is a cross-sectional view of the male component of the male element of the invention.  
       FIG. 4  is a perspective view of an embodiment of the invention.  
       FIG. 5  is a perspective view of the annular compression ring of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to a preferred embodiment of the invention, examples of which are also provided in the following description. Exemplary embodiments of this invention are described in detail, although it will be apparent to those skilled in the relevant art that some features that are not particularly important to an understanding of the invention may not be shown for the sake of clarity.  
      Furthermore, it should be understood that the invention is not limited to the precise embodiments described below and that various changes and modifications thereof may be effected by one skilled in the art without departing from the spirit or scope of the invention. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. In addition, improvements and modifications which may become apparent to persons of ordinary skill in the art after reading this disclosure, the drawings, and the appended claims are deemed within the spirit and scope of the present invention.  
      The present invention is directed to a novel grommet snap fastening device for fastening leather, fabrics, and sheet-like materials. The device comprises a male component and a female component. The male and female components are joined to one another to complete the fastener and to fasten the leather, fabric, or sheet-like material. Each of the male and the female components comprises a subassembly of upper and lower elements.  
       FIG. 1  is a cross-sectional view of an embodiment of grommet snap fastener  10  in an assembled state.  FIGS. 2 and 3  are cross-sectional views of embodiments of the male and female elements of the fastener, respectively.  FIG. 4  is a perspective view of the embodiment shown in  FIGS. 1-3 . The structure and assembly of the components of a preferred embodiment will be described with reference to  FIGS. 2 and 3 .  
      The terms “lower” and “upper” as used below in the present application are used solely for descriptive purposes, and should not be read or construed as imposing any structural limitations upon the orientation of the invention.  
      Male component  12  comprises lower male element  20  and upper male element  30 . Lower male element  20  includes an approximately cylindrical shaft  22  and an approximately cylindrical base  24  located coaxially with the shaft  22 .  
      Upper male element  30  includes an approximately cylindrical body  31 , a flange  38  attached to the body  31 , and an approximately cylindrical hole  32  formed coaxially with the body  31 . Chamfer  39  is located upon an edge formed by intersection of a surface of body  31  and an upper surface of upper male element  30 . Upper male element  30  also includes a groove  34  around the circumference of body  31 , the groove having an arcuate cross-section.  
      In an alternate embodiment, groove  34  may have a hemispherical, rectangular, or “v-shaped” cross-section. Additionally, more than one groove  34  may optionally be included.  
      Male component  12  is formed by attaching lower male element  20  and upper male element  30  by inserting shaft  22  within hole  32 . In a preferred embodiment, shaft  22  and hole  32  are dimensioned to provide an interference or force fit.  
      In alternative embodiments, adhesive, threads, set screws, or other suitable attachment mechanism may optionally be utilized independently or in conjunction with the above-described interference fit to secure lower male element  20  to upper male element  30 .  
      Chamfer  39  is formed along an edge formed by intersection of hole  32  and a lower surface of upper male element  30 , to facilitate alignment and insertion of shaft  22  within hole  32 .  
      Upon alignment, shaft  22  may be inserted within hole  32  by use of a set of upper and lower grommet dies, whereby lower male element  20  and upper male element  30  may each be placed within a die and force applied to one or both dies to perform the insertion and interference fit described above.  
      In a preferred embodiment, shaft  22  is positioned within an opening formed in fabric  71  prior to attachment of lower male component  20  to upper male component  30 , such that fabric  71  is securely held between an upper surface of base  24  and a lower surface of flange  38 .  
      Female component  14  includes at least lower female component  40 , upper female component  50 , and compression ring  60 .  
      Lower female component  40  includes central element  41 , central hole  44 , and flange  46 . Ridge  47  is located at an outer edge of flange  46 . Round  42  is located at an edge formed by intersection of an inner surface of central hole  44  and a lower surface of flange  46 .  
      The diameter of central hole  44  may vary along the axis of central hole  44 , such that the diameter may be larger at an intersection of central hole  44  and a lower surface of flange  46  than at an opposite end of central hole  44 .  
      Upper female component  50  includes central hole  52  and flange portion  58 . An inner flange  54  is also provided on upper female component  50 , inner flange  54  being sized such that a spring stop  55  and an inner hole  56  are defined. Notch  59  is formed in central hole  52  adjacent to a lower surface of upper female component  50 . Chamfer  57  is formed at an intersection of an upper and an outer surface of upper female component  50 .  
      In a preferred embodiment, as best seen in  FIG. 5 , compression ring  60  is annular or circular, and has an approximately circular cross-section. Compression ring  60  is preferably constructed of a material having spring properties, such as metal or another suitable material having spring properties.  
      Compression ring  60  may be formed as a solid ring without a gap, or alternatively may be formed with a gap to facilitate expansion and contraction.  
      Female component  14  is formed by inserting central element  41  of lower female element  40  within central hole  52  of upper female component  50 , with compression ring  60  being located the lower and upper female elements. Compression ring  60  is inserted into upper female element central hole  52 , and in contact with spring stop  55 , prior to assembly of lower female component  40  and upper female component  50 .  
      In a preferred embodiment, central element  41  and central hole  52  are dimensioned to provide an interference or force fit. In an alternative embodiment, adhesive, threads, set screws, or another suitable attachment mechanism may be optionally utilized, independently or in conjunction with the above-described interference fit.  
      Insertion of lower female element  40  within central hole  52  is facilitated by notch  59 , which facilitates alignment and positioning of lower female element  40  and upper female component  50  for assembly.  
      Upon assembly of female component  14 , compression ring  60  is therefore held in place by a surface of upper female element central hole  52 , a surface of spring stop  55 , and an upper surface of lower female element central element  41 .  
      In an alternative embodiment, multiple compression rings may be utilized, and the multiple compression rings may be identical or may have differing dimensions and/or spring properties.  
      Upon alignment, central element  41  of lower female element  40  may be inserted within central hole  52  of upper female component  50  by use of a set of upper and lower grommet dies, whereby each of the upper and lower female components may each be placed within a die and force applied to one or both dies to perform the insertion and interference fit described above.  
      In a preferred embodiment, upper female element  58  is positioned within an opening formed in fabric  70  prior to attachment with lower female component  40 , such that fabric  70  is securely held by compression between a lower surface of upper female component flange  58  and an upper surface of lower female component flange  46 .  
      In a preferred embodiment, ridge  47  acts to assist positioning of fabric  70  to upper female component  14 . In alternative embodiments multiple ridges having identical or dissimilar geometry may be included to assist in affixing female component  14  to fabric  70 .  
      As illustrated in  FIG. 1 , assembled male component  12  and female component  14  may be fastened by inserting shaft  31  into central hole  44  such that compression ring  60  is located within groove  34 .  
      In a preferred embodiment, upon insertion of shaft  31  into central hole  44 , chamfer  36  contacts compression ring  60  and acts to expand and guide compression ring  60  over shaft  31  and into groove  34 .  
      In a preferred embodiment, upon joining female component  14  and male component  12 , an upper surface of upper male element  30  is visible through upper female element central hole  56 . In a preferred embodiment, the upper surfaces of upper male element  30  and upper female element  50  may be approximately aligned.  
      In an alternative embodiment, body  31 , groove  34 , lower female element central element  41 , and upper female element  58  may be dimensioned to change the relative positions of the upper surface of upper male element  30  and upper female element  50  upon fastening.  
      Upon fastening, spring properties of compression ring  60  act upon the surface of groove  34  to locate and maintain the relative positions of male component  12  and female component  14 , thereby fastening fabric  71  to fabric  70  securely and conveniently.  
      What has been illustrated and described herein is a grommet snap fastening device. While the invention has been illustrated and described with reference to certain preferred embodiments, the present invention is not limited thereto. In particular, the foregoing specification and embodiments are intended to be illustrative and are not to be taken as limiting. Thus, alternatives, such as structural or mechanical equivalents and modifications will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, such alternatives, changes, and modifications are to be considered as forming a part of the present invention insofar as they fall within the spirit and scope of the appended claims.