Abstract:
A snap-fit fastener having deflectable, diverging wings extending from a distal end of a pedestal is provided with lead-in extensions from the connection of each wing to the pedestal. The extensions define a slot therebetween and are curved relative to the wings. By inserting an implement such as a screwdriver in the slot and twisting the implement, the lead-in extensions are spread relative to each other and the wings are moved toward the pedestal to allow the fastener to be disconnected from an object.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present regular United States Patent Application claims the benefit of U.S. Provisional Application Ser. No. 60/663,889 filed Mar. 21, 2005. 

   FIELD OF THE INVENTION 
   The present invention relates generally to fasteners, and more particularly to snap-fit fasteners made of plastic. 
   BACKGROUND OF THE INVENTION 
   Snap-fit plastic fasteners for securing one item or part to another in an assembly are used in many industries for many purposes. Such fasteners are known in a variety of shapes and configurations, and may have snap-fit connections to each component, interlocking engagement to one component, threaded engagement to one component or to a second fastener component and various other attachment configurations. 
   It is known in automotive applications to have one or more components that are pre-assembled at one location and shipped to another location for assembly with one or more other components. The pre-assembly may include installation of a fastener, such as a bolt and nut. The nut may be attached to the bolt prior to final assembly, requiring that the nut be removed from the bolt during final assembly only to be reattached to the bolt upon final assembly. So called part-in-assembly (PIA) applications wherein the fastener is connected to one part and transported to another location for final assembly in which the part with fastener is installed on the automobile have achieved broad acceptance. However, disassembly of a bolt and nut fastener is time consuming and sometimes problematic in that the removed nut can be dropped or misplaced, requiring that a spare nut be available for use. When a fastener having a nut is used, it is also necessary to keep the end of the fastener exposed for access to the nut until final assembly is completed. In other applications, a pre-assembly may only include a bolt. The nut is later assembled to the bolt during final assembly at the manufacturing plant. The nut increases cost, assembly time and sometimes requires the use of specialized tools. 
   Various types of deflectable fasteners, so-called“snap-fit” fasteners, have also been used in which one or both ends of the fastener are adapted for inward deflection as the fastener is forced into a hole of a part in which it is installed. The deflectable portion rebounds outwardly after passing through the hole, securing the fastener in the hole of the part. These types of fasteners have advantages in that the fastener is one-piece and can be assembled quickly by merely pushing the fastener into the part or pushing the part onto the fastener. Such fasteners also provide advantages in so-called blind fastening assemblies, wherein the first and second parts overlie each other covering the hole and the fastener, or in other applications there is no access to the inside of the hole or the installed fastener. For example, it is known to use snap-fit PIA assemblies to attach molding to a vehicle body. 
   A disadvantage of such fasteners is that the fastener can be difficult to remove. In some applications and uses, the retention force requirement is high such that the parts are not easily pulled off the fastener. Accordingly, such fasteners can be designed with relatively easy inward deflection of the components for insertion through a hole but configured such that the part is not easily deflected for extraction. In some situations, the fastener must be broken or otherwise damaged to remove one part from the other. When reapplying automobile trim to an automobile body, for example, it may be necessary to provide all new fasteners if the original fasteners are damaged upon removal of the trim for body repair or other servicing. Replacing the fasteners when reattaching the molding is both inconvenient and expensive. Further, removal is difficult and can be time consuming. 
   There is a need for a snap-fit fastener that can be pushed into parts for connection without requiring difficult attachment procedures, with the fastener being one piece and having a high extraction force but being removable and reusable. 
   SUMMARY OF THE INVENTION 
   The present invention provides a snap-fit fastener having deflectable wings that deflect inwardly for insertion of the fastener through a hole and rebound outwardly after passing through the hole to retain the fastener in the article. The fastener can be manipulated with a tool to cause the wings to deflect inwardly for detachment of the fastener from the component. 
   In one aspect thereof, the present invention provides a fastener with an anchor, and a pedestal extending from the anchor and having a distal end area First and second wings are connected to the pedestal via first and second hinge regions. The hinge regions are disposed near the distal end of the pedestal. The wings extend along and outwardly from the pedestal toward the anchor. First and second extensions are connected to the wings through the hinge regions, and define a slot therebetween having an entrance thereto axially outwardly from the pedestal. The first and second extensions are twisted relative to the wings. 
   In another aspect thereof, the present invention provides a fastener with an anchor portion having a head and a neck and a connecting portion having a pedestal and opposed laterally extending wings from a distal end area of the pedestal. The wings angle outwardly from the distal end area toward the anchor portion. A lead-in extension is associated with each wing. The lead-in extensions are twisted in a common direction relative to the wings and define a slot therebetween. 
   In a still further aspect thereof, the present invention provides a method for using a snap-in fastener having an anchor portion, a pedestal extending from the anchor portion and laterally extending wings from a distal end of the pedestal. The method has steps of: providing lead-in extensions from a hinged connection of the wings to the pedestal; providing a curvature to the lead-in extensions relative to the wings; providing a slot between the lead-in extensions; inserting an implement into the slot; and rotating the implement in the slot and thereby spreading the lead-in extensions and moving the wings toward the pedestal. 
   An advantage of the present invention is providing a snap-fit fastener that is easily attached and easily detached, while providing a high retention force. 
   Another advantage of the present invention is providing a snap-fit fastener that is one piece, requiring only a single operation for final installation. 
   Still another advantage of the present invention is providing a snap-fit fastener that can be manufactured easily and inexpensively. 
   Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a fastener in accordance with the present invention; 
       FIG. 2  is an elevational view of the fastener shown in  FIG. 1 ; 
       FIG. 3  is an elevational view of the fastener shown in  FIGS. 1 and 2 , illustrated rotated approximately 90° from the position shown in  FIG. 2 ; 
       FIG. 4  is a cross-sectional view of the fastener shown in  FIGS. 1-3 , the cross-section being taken along line  4 — 4  of  FIG. 3 ; 
       FIG. 5  is a top view of the fastener shown in the preceding drawings; 
       FIG. 6  is a cross-sectional view similar to that of  FIG. 4  but illustrating the fastener being manipulated with a screwdriver for detachment; and 
       FIG. 7  is a cross-sectional view of the fastener and screwdriver shown in  FIG. 6 , the view of  FIG. 7  being taken along line  7 — 7  of  FIG. 6 . 
   

   Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now more specifically to the drawings and to  FIG. 1  in particular, numeral  10  designates a fastener in accordance with the present invention. Fastener  10  is configured for securing one part or component (not shown) such as an automobile molding to a second part or component (not shown) such as an automobile body. Accordingly, fastener  10  includes an anchor portion  12  for connection to one of the components and a connecting portion  14  for attachment to the other component. It should be understood that the general size and shape can vary for the particular application of the present fastener without departing from the scope of the present invention. 
   In the exemplary embodiment shown, anchor portion  12  includes a head  16  and a neck  18 . Head  16  is rectangular, being longer in one direction than in another as can be seen from a comparison of  FIG. 2  and  FIG. 3 . As such, anchor portion  12  can be secured in a slot, such as a keyhole slot or other suitable fixture. For example, so-called dog-house fixtures can be used. It should be understood that other types of anchor portions also can be used including snap-fit or other types of connections, including threaded connections. Preferably, anchor portion  12  is configured together with the component to which it attaches such that after being fixed in position, anchor portion  12  restricts fastener  10  from rotating. 
   A pedestal  20  extends away from neck  18  and includes a distal end area  22  remote from neck  18 . First and second lateral wings  24 ,  26  are connected by hinge regions  28  and  30 , respectively, to pedestal  20  at distal end area  22 . First wing  24  and second wing  26  extend substantially along pedestal  20  but angle outwardly from pedestal  20  in the direction away from hinge regions  28 ,  30 . Wings  24 ,  26  include wing ends  32 ,  34  recessed inwardly slightly. In known fashion, wings  24 ,  26  can be deflected inwardly as fastener  10  is inserted through a hole or other opening in an item, allowing fastener  10  to be inserted therein until wings  24 ,  26  clear the opening and rebound again outwardly. Depending on the outward angle of wings  24 ,  26 , the resistance offered by hinge regions  28 ,  30  and the like, fastener  10  can be configured to resist pullout with different retention force. An umbrella seal  36  can be provided, in known fashion, at the transition between neck  18  and pedestal  20  to provide a seal along a surface of an object attached to connection portion  14 . 
   First and second wings  24 ,  26  are positioned in substantially direct opposed relationship, on opposite sides of pedestal  20 . In the exemplary embodiment, wings  24 ,  26  are substantially straight edged bodies but also can be of other shapes. Wing  24  has first and second side edges  40 ,  42  extending from hinge region  28  toward first wing end  32 . Similarly, second wing  26  includes a third edge  44  and a fourth edge  46  that extend from hinge region  30  toward second wing end  34 . Being positioned on opposite sides of pedestal  20 , first and second wings  24 ,  26 , respectively are spaced from each other. Accordingly, first side edge  40  is spaced but rotationally adjacent to fourth side edge  46 , being separated therefrom by a space designated generally with reference number  48  in the drawings. Similarly, second and third side edges  42 ,  44  are rotationally adjacent each other but spaced from each other by a space designated generally with reference number  50  in the drawings. 
   First and second lead-in extensions  60 ,  62  are connected to first and second wings  24 ,  26  via first and second hinge regions  28 ,  30 , respectively. First and second lead-in extensions  60 ,  62  are twisted bodies not in direct alignment with, but rotationally offset from the respective wing  24 ,  26  to which each is connected. A slot  64  is defined between first and second lead-in extensions  60 ,  62  and includes a substantially straight entrance or opening  66  and a base  68 . 
   First and second lead-in extensions  60 ,  62  are rotationally offset or twisted relative to first and second wings  24 ,  26 . Accordingly, first lead-in extension  60  has a first slot edge  70  rotationally outward of first side edge  40  and angularly disposed or curved toward first side edge  40 . Stated in another way, first slot edge  70  commences at entrance  66  in a location axially aligned with space  48  between fourth side edge  46  and first side edge  40  and extends therefrom in a curved path toward first side edge  40  at hinge region  28 . A second slot edge  72  is provided on the opposite side of extension  60  from first slot edge  70 , and extends in a curved line from a position at entrance  66  axially aligned between first and second side edges  40  and  42  toward second side edge  42  at hinge region  28 . 
   Lead-in extension  62  is configured similarly to lead-in extension  60  and is positioned with respect to second wing  26  similarly to the positioning of first extension  60  with respect to first wing  24 . Accordingly, second lead-in extension  62  includes a third slot edge  74  commencing at entrance  66  outwardly of second wing  26 , axially aligned with space  50  between second side edge  42  and third side edge  44 . Third slot edge  74  angles or curves toward second wing  26  and specifically third side edge  44  thereof at second hinge region  30 . A fourth slot edge  74  on the opposite side of second lead-in extension  62  commences at a location on entrance  66  axially aligned with second wing  26  between third and fourth sides edges  44 ,  46  and angles toward fourth side edge  46  at second hinge region  30 . 
   Slot base  68  continues the curvature defined by the aforementioned slot edges between lead-in extensions  60 ,  62 . Accordingly, as can be seen in  FIG. 1 , a base outer edge  78  of base  68  extends between fourth slot edge  76  and first slot edge  70 , along distal end area  22  of pedestal  20  and between hinge region  28  and hinge region  30 . As can be seen in  FIG. 2 , on the opposite side of base  68  from base outer edge  78 , a second base outer edge  80  extends between second slot edge  72  and third slot edge  74 , along distal end area  22  of pedestal  20  and between hinge region  28  and hinge region  30 . 
   In use, anchor portion  12  is secured to an appropriate fixture and a part or component is inserted via a hole therein (not shown) over connection portion  14  to be lodged against umbrella seal  36  and wing ends  32 ,  34 . To remove the component secured to connection portion  14 , first and second wings  24 ,  26  must be collapsed toward pedestal  20  to allow extraction back through the opening of the component. The present invention provides an easy, simple manner by which to disconnect fastener  10 . A screwdriver  90  ( FIGS. 6 &amp; 7 ) or other straight bladed implement is inserted in slot  64  via entrance  66 . Counterclockwise rotation of screwdriver  90  as illustrated in  FIG. 6  causes outward deflection of lead-in extensions  60 ,  62  ( FIG. 7 ) and corresponding inward deflection of first and second wings  24  and  26  via first and second hinge regions  28 ,  30 . In the inwardly adjusted position shown in  FIGS. 6 and 7 , connection portion  14  can be extracted from the hole of a part or component in which it is secured. 
   As shown and described for the exemplary embodiment, first and second lead in extensions  60 ,  62  are twisted in a clockwise direction relative to first and second wings  24 ,  26  as viewed in the end view of  FIG. 5 . However, it should be understood that lead in extensions  60 ,  62  can be curved in the opposite direction as well. It should be understood that if lead in extensions  60 ,  62  are twisted in the opposite direction from that shown, rotation of screwdriver  90  will be in a clockwise direction to spread lead in extensions  60 ,  62  and thereby adjust wings  24 ,  26  inwardly. 
   Fastener  10  can be provided with significantly high extraction resistance with strong, rigid hinge regions  28 ,  30 , and with first and second wings  24 ,  26  extending significantly beyond the edge defining a hole in which fastener  10  is secured. However, fastener  10  need not be broken or have the integrity thereof impaired if the connection to a part or component is reversed. By inserting screwdriver  90  or other implement and rotating as illustrated in  FIGS. 6 and 7 , wings  32  and  34  are adjusted for removal without compromising the integrity of fastener  10 . Accordingly, when screwdriver  90  is extracted from slot  64 , wings  32 ,  34  will rebound outwardly, and fastener  10  is suitable for reuse. 
   The installed condition of wings  24 ,  26  can be with wing ends  32 ,  34  engaged within a hole or slot of the item to which fastener  10  is connected. As such, lead-in extensions  60 ,  62  can be held in a moderate outwardly deflected condition, thereby enlarging a width entrance  66  for easy insertion of screwdriver or implement  90 . 
   Fastener  10  can be made of suitable plastic, and is conducive to injection molding or other inexpensive manufacturing techniques. Accordingly, fastener  10  can be provided inexpensively. 
   Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. 
   Various features of the invention are set forth in the following claims.