Abstract:
The fastener includes a post element, a blind aperture pivot assembly with a blind aperture into which the post element is inserted, and a rigid fastening member. The rigid fastening member secures around the post. The inclined rotationally symmetric wall deflects upon insertion into the blind aperture, but then interferes with the walls of the blind aperture to resist withdrawal.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains to a push-in fastener assembly. The fastener assembly includes a rigid member which is affixed to a fastener which is inserted into a blind aperture. The rigid member flexes and interferes with the aperture by way of an oblique rotationally symmetric wall. 
     2. Description of the Prior Art 
     In the prior art, fasteners for plastic panels are known. However, many of these fasteners are deficient when used with apertures formed in softer plastics which can be scooped or gouged by the fastener. Additionally, many of these fasteners have required complicated installation procedures which increased installation costs. 
     Some examples of fasteners are disclosed in U.S. patent application Ser. No. 09/412,227 entitled “Blind Aperture Fastener” filed on Oct. 5, 1999; U.S. Pat. No. 5,522,635 entitled “Tonneau Cover and Frame for Pick-Up Trucks” issued on Jun. 4, 1996 to Downey; U.S. Pat. No. 5,469,606 entitled “Clamp Means for Joining Objects Together” issued on Nov. 28, 1995 to Hansen; U.S. Pat. No. 5,098,242 entitled “Plastic Fastener for Threaded Stud” issued on Mar. 24, 1992 to Schaty; U.S. Pat. Nos. 4,750,878 and 4,624,585, both entitled “Retainer Bushing” issued on Jun. 14, 1988 and Nov. 25, 1986, respectively, to Nix et al.; U.S. Pat. No. 3,551,963 entitled “Self-Locking Snap Fastener” and issued on Aug. 16, 1968 to Mosher, Jr. et al.; U.S. Pat. No. 1,849,604 entitled “Fastening and Connecting Device” issued on Aug. 1, 1929 to Weatherhead, Jr.; and U.S. Pat. No. 207,871 entitled “Elastic Packing for Pistons” issued on Sep. 10, 1878 to Horton et al. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a fastener assembly which can be used with softer plastics with minimized gouging or scooping of the plastic. 
     It is therefore a further object of the present invention to provide a fastener assembly which can be installed with a simple motion thereby resulting in reduced installation costs. 
     It is therefore a further object of the present invention to provide a fastener assembly which fastens securely. 
     It is therefore a still further object of the present invention to provide a fastener assembly which can be manufactured economically. 
     These and other objects are attained by providing a fastener with a post which supports an outwardly concentric rigid member, preferably metallic, with an oblique rotationally symmetric wall which interferes with the blind aperture. The oblique rotationally symmetric wall is configured so that the lesser diameter oriented in the direction of insertion of the post into the blind aperture. Therefore, instead of gouging or scooping the walls of the blind aperture, there is a controlled predictable deflection of the oblique rotationally symmetric wall of the rigid member against the walls of the blind aperture of the blind aperture pivot assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages will become apparent from the following description and claims, and from the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of the post of the fastener assembly of the present invention. 
     FIG. 2 is a side plan view of the post of the fastener assembly of the present invention. 
     FIG. 3 is a cross-sectional view along plane  3 — 3  of FIG. 2 of the post of the fastener assembly of the present invention. 
     FIG. 4 is a top plan view of the post of the fastener assembly of the present invention. 
     FIG. 5 is a perspective view of the fastener assembly of the present invention, shown in a coupled configuration. 
     FIG. 6 is a side plan view, partially in phantom, of the fastener assembly of the present invention, shown in a coupled configuration. 
     FIG. 7 is a cross-sectional view along plane  7 — 7  of FIG. 6 of the fastener assembly of the present invention, shown in a coupled configuration. 
     FIG. 8 is a perspective view of the rigid fastening member of the fastener assembly of the present invention. 
     FIG. 9 is a plan view of the rigid fastener member of the fastener assembly of the present invention. 
     FIG. 10 is a cross-sectional view along plane  10 — 10  of FIG. 9 of the rigid fastener member of the fastener assembly of the present invention. 
     FIG. 11 is a top plan view of the rigid fastener member of the fastener assembly of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings in detail wherein like numerals refer to like elements throughout the several views, one sees that FIGS. 1-4 illustrate the post  12  of fastener assembly  10 . 
     Post  12  includes a lower cylindrical portion  14  which terminates in lower chamfered end  15 . Lower cylindrical portion  14  further includes lower circumferential groove  16 . Lower circumferential groove  16  includes upper wall  18  which is somewhat chamfered with respect to the wall of lower cylindrical portion  14 . However, lower wall  20  of lower circumferential groove is somewhat orthogonal. Lower cylindrical portion  14  further includes upper circumferential groove  22  which has a broad semi-circular cross section. Cylindrical disk  24  is formed above lower cylindrical portion  14  and serves as a stop for the insertion of post  12 , as will be explained hereinafter. 
     Handle portion  30  is formed above cylindrical disk  24  and includes tapered rotationally symmetric stem  32  and knob  34 . 
     Post  12  is typically an integral piece made from 33% glass filled nylon, although those skilled in the art will recognize that a range of equivalents is available. 
     As shown in FIGS. 5-7, lower cylindrical portion  14  is inserted into blind aperture  42  of blind aperture pivot assembly  40 . Blind aperture pivot assembly  40  is typically cylindrical in shape and is typically made from polycarbonate, 20% talc filled polypropolene, nylon, thermoplastic or can be part of a larger molded piece. Those skilled in the art will recognize other equivalents. 
     Rigid fastening member  50 , which is illustrated in detail in FIGS. 8-11, is secured to lower cylindrical portion  14  of post  12  and interferes against the walls of blind aperture  42  thereby securing post  12  to blind aperture pivot assembly  40 . 
     As shown in FIGS. 8-11, rigid fastening member  50  includes cylindrical walls  52  with lower oblique inwardly extending lip  54  and upper oblique rotationally symmetric wall  56 . Upper oblique rotationally symmetric wall  56  forms mouth  58  therewithin. Upper oblique rotationally symmetric wall  56  is angled so that the largest diameter opening is presented at mouth  58 , with the diameter progressively decreasing to the diameter of the interior of cylindrical walls  52 . Lower oblique inwardly extending lip  54  engages or extends into lower circumferential groove  16  of lower cylindrical portion  14  of post  12 . In some applications, rigid fastening member  50  may be able to pivot with respect to post  12 . Slots  60  are formed along cylindrical walls  52  of rigid fastening member  50  upwardly adjacent from lower oblique inwardly extending lip  54 . Slots  60  allow the lower portion of cylindrical walls  52  to expand during assembly (that is, when lower cylindrical portion  14  of post  12  is inserted into rigid fastening member  50  via mouth  58 ). The length and width of slots may vary, as would be known to those skilled in the art after review of the above, depending upon the diameter of post  12  being inserted and the material of the rigid fastening member  50 . 
     Upper oblique rotationally symmetric wall  56  is relatively easily inserted into blind aperture  42  without scooping or gouging the material of blind aperture pivot assembly  40 . However, due to the angle of inclination of upper oblique rotationally symmetric wall  56  with respect to a projection of cylindrical wall  52 , illustrated at about 30°, upper oblique rotationally symmetric wall  56  interferes with blind aperture  42  and resists being pulled out of blind aperture  42  after insertion therewithin. The angle of 30° can be reduced if stiffer material is used with the blind aperture pivot assembly  40  or if a lesser minimum pull-out force is required. Typically, a range of about 15-75° is envisioned depending upon the application. Additionally, the upper oblique rotationally symmetric wall  56  does not necessarily have to be a full diameter, but alternately can be formed as segments as shown in FIG.  11 . That provides an alternate way to control insertion and removal force. 
     Rigid fastening member  50  is primarily envisioned as being made by eyelet manufacturing equipment using 300 series stainless steel. However, if rigid fastening member  50  is shortened, progressive die tooling could be used. Carbon steel, if plated to guard against corrosion, and if necessary, heat treated, could similarly be substituted for the stainless steel. For applications requiring a lower minimum pull-out force, plastics or some engineering grade polymers could even be substituted. 
     To use fastener assembly  10 , the user first inserts post  12  into mouth  58  of rigid fastening member  50  until lower oblique inwardly extending lip  54  is engaged within lower circumferential groove  16 . Upper circumferential groove  22  then allows for inwardly flexure of cylindrical wall  52 , particularly proximate to upper oblique rotationally symmetric wall  56 . The user then inserts post  12  with rigid fastening member  50  attached thereto into blind aperture  42  of blind aperture pivot assembly  40  until cylindrical disk  24  is flush with either blind aperture pivot assembly  40  or an apertured panel engaged therebetween (not shown). Upper oblique rotationally symmetric wall  56  deflects somewhat during insertion but thereafter interferes with the walls of blind aperture  42  thereby securing post  12  within blind aperture pivot assembly  40 . 
     Thus the several aforementioned objects and advantages are most effectively attained. Although a single preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.