Abstract:
A fastener for use for attaching metal parts has a socket member and a stud member slidably and fixedly received therein. A flair portion on the socket member expands when abutted by a camming portion on the stud member to move the fastener between unlocked and locked positions. The head of the stud member includes a beveled edge which complementarily fits against a bevel abutment within the socket head. The bevel abutment extracts the stud member from the locked position by turning the stud member in either axial direction to ramp the stud member out of the socket member.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a fastener which is used to fasten adjacent panels to each other. More particularly, the present invention relates to a turn fastener used to removably fasten together two panels, each having a rectangular aperture therethrough. Specifically, the removable turn fastener of the present invention is comprised of a stud element which fits into a receptacle element, wherein the receptacle element is sized to be removably received by the rectangular apertures of the panels. The removable turn fastener provides beveled edges and abutments to replace screw-type threading and prevent wear. The fastener further provides a low profile head in the locked position which is aesthetically pleasing and prevents snagging of material. Finally, the fastener may be locked and unlocked manually with only one hand using one quarter turn, and does not require the user to manually brace any part of the fastener while locking or unlocking. 
         [0003]    2. Background Information 
         [0004]    It is frequently desired, both in industrial and consumer products, to secure two or more panels, plates or sheet-like structures to one another. Many types of fasteners permit the panels to be separated and later refastened. However, although many types of fasteners have been commercially produced, and many more types have been proposed, there exists a need for improvements in the field. 
         [0005]    One general type of fastener comprises a stud member which fits into a socket member positioned in a hole in a panel. The stud member may be rotated to expand the socket member outwardly and grip the edges or sidewall of the panel hole. One fastener of this general type is shown in U.S. Pat. No. 4,331,413 to Hoen, wherein a stud member fits into a socket member. Fingers on the end of the socket member are expanded through pressure from the stud member to grip the aperture sidewalls and prevent removal of the fastener. However, several distinctions and drawbacks exist in such fastener constructions which are remedied in the present invention. 
         [0006]    Fasteners such as shown in Hoen are constructed and configured for securing panels through a round aperture. Round apertures and corresponding round socket members inherently may axially rotate with respect to one another due to the lack of rotation stopping edges. This is a significant problem when the means to secure the stud member to the socket member is through axial rotation of the stud member. This axial rotation of the stud member is transferred to the socket member and “slippage” occurs, typically resulting in the user holding the socket member with one hand, while rotating the stud member with the other. If the panels are sufficiently large such that the user cannot extend both arms around the panel, another user must be present to hold the socket member or rotate the stud member. Prior art fasteners such as shown in Hoen do not disclose how axial slippage of the socket member within the round aperture is prevented, and this may be a drawback to such fasteners. 
         [0007]    A further drawback to such prior art fasteners is the extending nature of the stud member when the handle is rotated about its axis to open the fingers of the fastener. Upon rotation of the expanding handle, the stud member is moved upwardly along its axis. This extends the length of the entire fastener by the handle protruding outwardly when in the fastened position. For most typical fastener applications, a low profile of the stud member while in the fastened position is desired. There are many commercial and retail situations where it requires that a portion of the overlapping panels have no distinct protrusions generally above the plane of the panel itself. If the fastener is to be included in a retail setting, such as within a shelving unit, or display structure, the fastener head protruding out of the panels when in the locked position must be generally aesthetically pleasing as well as formed to not snag on any materials passing over it. These requirements are difficult to achieve with known fasteners wherein the stud member and ramp elements inherently extend from the fastener and panels. 
         [0008]    A further drawback in the field of fasteners is the use of threading and screw-type structures to move the fastener between locked and unlocked positions. Threading tends to degrade with time, leading to “stripping” of the threads, rendering the fastener useless. Furthermore, when a user applies pressure to a stud member having threading, the user must be careful to not exert too much pressure on the stud member, or risk pushing the stud member over the threading. This requires the user to slowly rotate the stud member around through the threading, dramatically slowing down the assembly process of a large structure. Screw threading also typically requires more than a quarter turn to move the fastener from an unlocked to locked position. This is inefficient in both the time and effort of the user, as a fastener which uses screw-type threading to move the fastener from an unlocked to locked position will inherently require more time and concentration of the user. 
         [0009]    Heretofore, existing turn fasteners have been characteristically inefficient and lacking in axial stability while the stud member is being rotated therein, requiring two hands or two users to complete the fastening process. Existing turn fasteners have been further inefficient in requiring a screw-type threading element and correspondingly inefficient fastening procedure. Furthermore, existing turn fasteners have been inefficient in reducing the profile of the stud member while in a fastened position. 
         [0010]    Therefore, the need exists for a turn fastener having a socket member which is naturally stabilized while in the aperture and does not slip while the stud member is being rotated within. Furthermore, the need exists for a turn fastener which retracts the stud member entirely within the socket member when in the fastened position, and does not include threading elements or screw-type axial rotation to lock or unlock the fastener. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    A primary object of this invention is to provide a fastener for securing plate-shaped metal parts and which can be manually and easily moved between a locked and unlocked position. The present invention provides for a non-threaded stud member rotating within a non-threaded socket member to expand and contract a squared shaped flair section to move the fastener between an unlocked and locked position. 
         [0012]    Another object of the invention is provide a fastener which conforms to fit into a square hole. 
         [0013]    A further object of the invention is to provide a fastener which may be used in a retail setting. The fastener has a low profile head when in the locked position to prevent materials from being snagged by a protruding member. The fastener head also is aesthetically pleasing to be viewed in a retail setting. 
         [0014]    It is another object of the invention to provide a fastener which does not include threading such as found in a screw-type structure. 
         [0015]    Another object of the invention is to provide a fastener which is locked and unlocked with one hand, and does not require the user to brace any portion of the fastener. 
         [0016]    It is another object of the invention to provide a fastener which does not rotate axially within an aperture. 
         [0017]    These features are obtained by the fastener for attaching metal parts, the general nature of which includes a fastener for securing together first and second plates, each plate having a rectangular hole formed therein, said fastener comprising: a socket member having a head, a lower flair portion and a shaft extending therebetween, said shaft having a plurality of walls forming a central bore having an imaginary axis and providing a rectangular configuration; and a stud member telescopically received in the bore of the socket member and having a lower camming portion engageable with the flair portion of the socket member for expanding the flair portion outwardly into clamping engagement with one of the plates and locking the stud member to the socket member upon axial and rotational movement of the stud member along and about the imaginary axis. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0018]    A preferred embodiment of the invention, illustrated of the best mode in which Applicant contemplates applying the principles, is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims. 
           [0019]      FIG. 1  is a perspective view of the fastener of the present invention for attaching a pair of panels; 
           [0020]      FIG. 2  is an exploded perspective view thereof; 
           [0021]      FIG. 3  is a side elevational view of the stud member; 
           [0022]      FIG. 4  is a front elevational view of the stud member; 
           [0023]      FIG. 5  is a front elevational view of the socket member; 
           [0024]      FIG. 6  is a front sectional view of the socket member; 
           [0025]      FIG. 7  is a perspective view of the fastener for joining together two panels having square holes therein; 
           [0026]      FIG. 8  is an enlarged sectional view taken on line  8 - 8  of  FIG. 7  and with the fastener shown in section; 
           [0027]      FIG. 9  is perspective view of the fastener in an unlocked position and placed into the square holes in the two panels of  FIGS. 7 and 8 ; 
           [0028]      FIG. 10  is an enlarged sectional view taken on line  10 - 10  of  FIG. 9 ; 
           [0029]      FIG. 11  is a sectional view taken on line  11 - 11  of  FIG. 10 ; 
           [0030]      FIG. 12  is a perspective view of the fastener in a locked position joining together the two panels; and 
           [0031]      FIG. 13  is an enlarged sectional view taken on line  13 - 13  of  FIG. 12 . 
       
    
    
       [0032]    Similar numbers refer to similar parts throughout the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    The fastener of the present invention is generally indicated at  1 , and is shown in  FIGS. 1-13 . Referring to  FIGS. 1 and 2 , fastener  1  is comprised of a stud member  3  received by a socket member  5 , and an imaginary central axis  2  extending the length of fastener  1 . Fastener  1  operates to move between a locked position as shown in  FIGS. 12 and 13  and an unlocked position as shown in  FIGS. 1 and 10 . 
         [0034]    Referring to  FIGS. 2-4 , stud member  3  is comprised of a head  7 , a lower camming portion  9 , and a round cylindrical non-threaded shaft  11  extending therebetween. Head  7  has a flat top surface  13 , a bottom surface  15  and a sidewall  17  extending therebetween and circumferentially axially about central axis  2  and having a diameter greater than that of shaft  11 . Found in bottom surface  15  is a pair of spaced apart beveled edges  19 . As shown in  FIGS. 1 and 2 , an elongated rectangular-shaped turn recess  14  is formed in the center of head  7 . Camming portion  9  of stud member  3  is comprised of a first, second, and third sloped wall,  21 ,  23 , and  25 , respectively ( FIGS. 3 and 4 ). First sloped wall  21  and second sloped wall  23  merge to form an annular recess  27 . Second sloped wall  23  and third sloped wall  25  merge to form an annular cam ridge  29 . An annular retainer shoulder  20  is formed on the lower end of shaft  11  and terminates at first sloped wall  21 . 
         [0035]    Referring to  FIG. 2 ,  5 , and  6 , socket member  5  is comprised of an annular head  31 , a lower flair portion  33 , and a square shaft  35  extending therebetween. Head  31  includes a top rim  37 , a bottom shoulder  39  and a cylindrical sidewall  41  extending axially therebetween about central axis  2 . Rim  37  and sidewall  41  define an annular recess  43  formed in head  31  and is sized to receive head  7  of stud member  3  therein as shown in  FIGS. 12 and 13 . Square shaft  35  is comprised of four generally flat walls  45  arranged to form a generally square cross-sectional shape. Shaft walls  45  have a cylindrical hole or bore  47  extending the length of socket member  5  along central axis  2  and opening at top and bottom ends  34  and  36 , respectively. 
         [0036]    As shown in  FIG. 6 , a pair of spaced bevel abutments  49  extend from a recess base  51  along a cylindrical wall  53  which forms recess  43  and are sized to abut beveled edges  19  of stud member  3  when fastener  1  is in the locked position as shown in  FIG. 13 . Flair portion  33  extends from square shaft  35  and is comprised of four finger members  55  having a longitudinally extending space  54  between each pair of finger members. Each finger member  55  is an extension of shaft wall  45  and has a first or top end or shoulder  57  and a second or bottom end  59 , an inner surface  61  and an outer surface  63 . Each finger member  55  further includes a tapered shoulder  65  on inner surface  61  sized to complementary abut recess  27  of stud member  3  when fastener  1  is in the locked position. An annular inner stud retainer ring  67  is formed on stud walls  45  at the top end of bore  47  proximate bottom surface  39  of socket head  31  and extends inwardly towards axis  2  as shown in  FIGS. 6 and 8 . 
         [0037]    The interaction between stud member  3  and socket member  5  of fastener  1  is shown particularly in FIGS.  1  and  7 - 13 . Stud member  3  is slidably received and fixed within bore  47  of socket member  5 . Stud member  3  is prevented from withdrawing and separating from top end  34  of socket member  5  by stud retainer ring  67 . If stud member  3  is attempted to be withdrawn from socket member  5 , stud retainer ring  67  abuts stud retainer shoulder  20  on shaft  11  and prevents shoulder  20  from passing ring  67 . Conversely, stud member  3  is prevented from withdrawing and separating from bottom end  36  of socket member  5  by the base of recess  43 . As stud member  3  is inserted axially in bore  47  towards bottom end  36 , recess base  51  abuts bottom surface  15  of head  7  on stud member  3  and prevents stud member  3  from passing beyond the abutment point. Thus, stud member  3  is prevented from separating from socket member  5  at top end  34  and bottom end  36  once it is inserted into bore  47  of socket member  5 . 
         [0038]    As shown in  FIG. 7 , fastener  1  is sized to be inserted into a complementary-shaped square hole  69  and fasten a first plate or panel  71  to a second plate or panel  73 . Plates  71  and  73  each include a square aperture  72  and  74 , respectively, which are aligned and sized to form square hole  69 . As shown in  FIG. 7-10 , fastener  1  and more particularly first end  34  of socket member  5 , including flair portion  33  and square shaft  35 , enters hole  69  and penetrates until bottom surface  39  of socket member  5  abuts first plate  71  preventing socket member  5  from extending farther into hole  69 . As shown in  FIG. 10 , manual pressure is applied to socket member  5  in the direction of Arrow A to push it into hole  69 . When socket member  5  is fully inserted into hole  69 , head  7  is abutting the top surface of plate  71 . Camming portion  9  of stud member  3  does not actuate or cam finger members  55  outwardly while in the unlocked position as shown in  FIG. 10 . In this position, camming surface  25  will abut angled surfaces  64  of finger members  55  fully seating head  7  within recess  43  providing a flush fit therebetween. 
         [0039]    As shown in  FIGS. 12 and 13 , to move fastener  1  from the unlocked position of  FIG. 10  to the locked position of  FIG. 13 , manual pressure is exerted in the direction of Arrow B on stud member  3  moving stud member  3  farther into bore  47 . Beveled edges  19  of stud head  7  must align with bevel abutment  49  within recess  43  of socket member  5  to fully lock fastener  1 . A screwdriver or any other manual turning device is inserted into recess  14  to rotate stud member  3  one-quarter turn in the directions of Arrow C to properly align beveled edges  19  with bevel abutment  49 , thus fully locking fastener  1 . As shown in  FIG. 13 , fastener  1  is in the locked position having beveled edges  19  of stud member  3  properly and complementary aligned with bevel abutments  49  in recess  43  of socket member  5  and flat surface  15  of stud member  3  abutting recess base  51 . 
         [0040]    As stud member  3  is pressed in the direction of Arrow B ( FIG. 13 ), a camming interaction occurs between camming portion  9  on stud member  3  and shoulder  65  on each finger member  55 . As stud member  3  is pressed in the direction of Arrow B, third sloped wall  25  of camming portion  9  slides over a face  64  on shoulder  65 . Each shoulder  65  on finger member  55  is cammed outwardly from central axis  2  in the direction of Arrows D until shoulder  65  passes over cam ridge  29 . Next, the angle of second sloped wall  23  allows shoulder  65  to slightly retract towards central axis as stud member  3  moves against shoulder  65 . Finally, shoulder  65  comes to rest positioned in recess  27  as a result of the complementary shape of face  64  and shoulder  65  with recess  27  formed by first sloped wall  21  and second sloped wall  23 . Pressure from finger members  55  in the opposite direction of Arrows D holds shoulders  65  tightly within recess  27 . 
         [0041]    In the locked position of  FIG. 13 , finger members  55  are cammed outwardly from central axis  2  by stud member  3  giving flair portion  33  of socket member  5  a greater cross-sectional area than hole  69 . Thus, flair portion  33  of socket member  5  cannot be retracted through square hole  69  while fastener  1  is in locked position  4 . Correspondingly, head  31  of socket portion  5  cannot be retracted through hole  69  while fastener  1  is in either locked or unlocked positions. Thus, fastener  1  is not removable from square hole  69  when in the locked position and plates  71  and  73  are held securely together. 
         [0042]    To move fastener  1  from the locked position to the unlocked position, stud member  3  is manually retracted in the opposite direction from Arrow C. As shown in  FIGS. 12 and 13 , top surface  13  of stud member  3  is horizontally flush with rim  37  of socket member  5 , preventing a user from grasping the sides of head  7  to pull stud member  3  out of locked position  4 . However, by manually turning stud member  3  one-quarter turn, beveled edges  19  slide away from bevel abutments  49  and the non-beveled sections of head  7  encounter bevel abutments  49 . When non-beveled sections of head  7  are turned over bevel abutments  49 , stud member  3  is drawn upwardly by the angled nature of bevel abutments  49  and released from the locked position. During this interaction, shoulder  65  slides out of recess  27  along second sloped wall  23 , and finger members  55  retract to the original cross-sectional area, allowing fastener  1  to be withdrawn from hole  69 . 
         [0043]    In operation, a user places two plates  71  and  73  together, each having square apertures  72  and  74  respectively, which forms square hole  69 . The user then places fastener  1  into hole  69 , and more specifically places flair portion  33  and square shaft  35  into hole  69 , with head  31  of socket member  5  preventing fastener  1  from entering farther into hole  69 . Plates  71  and  73  may be of any type of material common in the art, but typically are comprised of metal sheeting. Furthermore, fastener  1  may have a shape and size generally complementary to hole  69  and will be packaged together for products such as shelving units or display racks, having a certain size or sizes of holes  69 . 
         [0044]    Once fastener  1  is placed into hole  69 , the user moves fastener  1  from the unlocked position to the locked position by applying downward and rotational pressure on head  7  of stud member  3 . This drives stud member  3  down into bore  47  of socket member  5 , aligning beveled edges  19  and bevel abutments  49 , and camming finger members  55  outwardly and away from central axis  2 . Camming portion  9  forces shoulder  65  over cam ridge  29  and into recess  27 . This holds finger members  55  extended outwardly from central axis  2  and prevents fastener  1  from being removed as flair portion  33  is larger than hole  69 . The user is now free to manipulate plates  71  and  73  as a unit as they are securely fastened by fastener  1 . 
         [0045]    Conversely, when the user wants to remove fastener  1  from plates  71  and  73 , the process is reversed. The user manually turns head  7  of stud member  3  one-quarter turn by use of a screw driver or similar device in recess  14 , which rotates the non-beveled sections of head  7  over bevel abutment  49 , drawing stud member  3  out of bore  47 . Camming portion  9  retracts away from shoulder  65 , thus allowing finger members  55  to retract and allowing flair portion  33  to pass through hole  69 . Preferably hole  69  will be equal to or just slightly greater than the outer dimensions of flair portion  33 . Fastener  1  is then removed and panels  71  and  73  can be separated from each other. 
         [0046]    When turning head  7  of stud member  3 , the user requires only one hand to move the fastener between locked and unlocked positions. Square shaft  35  abutting the walls of square hole  69  prevents axial movement of fastener  1  about central axis  2 , allowing the user to turn stud member  3  without holding socket member  5 . This dramatically increases the time to secure multiple fasteners  1  across a large plating structure as one user can place each fastener  1  in each square hole  69  and then quickly go down the line locking each fastener  1  with a pressured turn. Furthermore, head  7  of stud member  3  is recessed into head  31  of socket member  5  when fastener  1  is in the locked position as shown in  FIGS. 12 and 13 . The flush nature of head  7  and head  31  creates an aesthetically pleasing structure, which also prevents snagging of materials. This allows fasteners  1  to be used in a retail setting where customers may view fasteners  1  which provides an attractive appearance, as well as brush up against panels  71  or  73  without injuring the customer. Further, the beveled edges  19  acting in concert with bevel abutments  49 , and the absence of threading allows fastener  1  to be used and reused much longer than a traditional screw-type of structure where the threads degrade over time and require a specific pressure when turning. 
         [0047]    Although the above fastener members  3  and  5  are shown and described as being square-shaped and used in square-shaped holes, it is readily understood that other non-circular shapes could be used with satisfactory results by preventing rotation of the socket member  5  in hole  69  and preventing rotation of stud member  3  within bore  47  of socket member  5 . Also, plates  71 ,  73  can be various other structures other than flat plates or panels which can be joined by fastener  1 . Fastener  1  can be metal or plastic and function equally well in various fastening applications. 
         [0048]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
         [0049]    Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.