Abstract:
A non-friction, interlocking fastener with a bolt that is locked into a retainer incorporating an integral spring with limited compression and which is axially constrained to prevent non-linear movement.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Provisional Patent Application No. 60/567,469, filed Dec. 6, 2011. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a self-locking, threadless fastener 
       BACKGROUND OF THE INVENTION 
       [0003]    There is a need for a self-locking fastener that firmly fastens work pieces together and is able to withstand considerable vibration, tension and shear loads. A wide variety of high strength threadless fasteners have been available, such as shown in U.S. Patent Publication Nos. 2007/0196196 to Schorling and Keech and 2005/0008458 to Keech and Grodeman. Integral machined springs are known, such as shown by U.S. Pat. No. 4,790,700 to Schwartzman. Self-locking fasteners are known that use a retaining ring in a groove, such as shown in U.S. Pat. No. 4,948,316 to Duran, Young, and Chang. A tool using moving jaws to Compress a snap ring is shown in U.S. Pat. No. 6,678,930 to Owoc. However, none of these prior art fasteners have succeeded in the goal of providing a self-locking threadless fastener that is easy to install and which provides high strength resistance to vibration, tension and shear loads. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    The present invention is directed to a fastener that accomplishes the foregoing goal, a fastener that is improved in many respects in comparison to the threadless fasteners that have been available in the past. More specifically, the present invention provides a non-friction, interlocking fastener with a bolt that is locked into a receptacle, the fastener incorporating an integral spring with limited compression and which is axially constrained to prevent non-linear movement. 
         [0005]    The fastener employs the axially constrained spring action to securely hold together panels or other work pieces. In one embodiment, the axial spring is positioned in the receptacle on one side of a work piece to receive the bolt, which enters the receptacle from the other side of the work piece. In another embodiment, the axial spring is positioned in a housing on the opposite side of the work piece and which contains the bolt to be inserted into the receptacle through the work piece. The use of a deformable integral spring gives the fastener considerable holding power because of the expansion of the integral spring when applied to the fastened parts. The fastener is self-locking through the expansion of a retaining ring carried on the bolt into an internal groove on the receptacle to inter-lock the fastened parts. When subjected to vibrational forces which try to pull the fastener apart, the deformable spring deflects with greater clamping force. The fastener bolt does not have threads which in prior art fasteners are subject to loosen under vibration. To improve the fastener fatigue performance, a co-axial sleeve limits the spring compression travel. 
         [0006]    The fastener is axially installed and removed with a special tool used to insert the fastener bolt into the fastener retainer. It consists of four two-position control levers: (a) a retractable plunger that extends and retracts to align the tool on the head of the bolt; (b) a clamp end angle controller for rotating a clamp end from vertically directed to horizontally directed to sequentially enable the clamp to be inserted through the bolt and receptacle, then engage the receptacle to enable compression of the integral spring; (c) a retaining ring lever to compress and uncompress the retaining ring; and (d) a clamp lever to extend and retract the clamp. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
           [0008]      FIG. 1  is a cross-section view of the fastener assembly showing the fastener retainer secured on the bottom side of a first work piece and a fastener bolt aligned on the top side of a second work piece to be secured together by the fastener; 
           [0009]      FIG. 2  is an exploded, perspective view of the three parts of the fastener receptacle; 
           [0010]      FIG. 3  is a cross-section view of the fastener receptacle and work piece; 
           [0011]      FIG. 4  is a perspective view of the fastener bolt components including a retaining ring for locking the bolt to the receptacle and a wire ring captive lanyard; 
           [0012]      FIG. 5  is a perspective view of the assembled fastener bolt, showing a cut off section; 
           [0013]      FIG. 6  shows the fastener lifted by a spring lanyard when not engaged; 
           [0014]      FIG. 7  is a perspective view of the fastener assembly, and wire captive lanyard, secured across first and second work pieces; 
           [0015]      FIG. 8  shows plan and perspective views of a bolt retaining ring used in the invention, in a relaxed state with no load applied while seated on the bolt body prior to assembly of the fastener; 
           [0016]      FIG. 9  shows plan and perspective views of the retaining ring fully compressed while seated on the bolt body to create a clearance fit between the receptacle groove and the outside surface of the retaining ring during fastener assembly; 
           [0017]      FIG. 10  shows plan and perspective views of the retaining ring partially compressed by contact between the outer surface of the ring and the inner surface of the receptacle groove at final fastener assembly; 
           [0018]      FIG. 11  is a plan, partially cut-away view of the fastener with the retaining ring fully compressed, as in  FIG. 9 , while seated on the bolt body to create a clearance fit between the receptacle groove and the outer surface of the retaining ring during fastener assembly; 
           [0019]      FIG. 12  is a plan, partially cut-away view of the fastener with the retaining ring partially compressed, as in  FIG. 10 , by contact between the outer surface of the ring and the inner surface of the receptacle groove at final fastener assembly. 
           [0020]      FIG. 13  is an elevation view of the retaining ring lever component of a tool used to load and lock the fastener bolt to the fastener receptacle; 
           [0021]      FIG. 14  is an elevation, partially cross-section, view of the base component of the tool; 
           [0022]      FIG. 15  is a plan view of the tool at its initial lever setup; 
           [0023]      FIG. 16  is a plan view of the tool and fastener bolt positioned for insertion of the tool into the fastener bolt; 
           [0024]      FIG. 17  is a plan view of the tool fully inserted into the fastener bolt; 
           [0025]      FIG. 18  is a plan view of the tool fully inserted into the fastener, secured across first and second work pieces; 
           [0026]      FIG. 19  is a plan view of the fully inserted tool as in  FIG. 18  but with the clamp end rotated from vertically directed to horizontally directed; 
           [0027]      FIG. 20  is a plan view of the fully inserted tool as in  FIG. 19  but with the retaining ring compressed and the clamp lever rotated to load the fastener; 
           [0028]      FIG. 21  is a plan view of the fully inserted tool as in  FIG. 20  but with the retaining ring slightly compressed and released into the receptacle groove; 
           [0029]      FIG. 22  is a plan view of the fully inserted tool as in  FIG. 21  but with the clamp lever rotated to unload the fastener; 
           [0030]      FIG. 23  is a plan view of the fully inserted tool as in  FIG. 22  but with the clamp end rotated to from horizontally directed to vertically directed and the plunger retracted, to enable the tool to be removed from the fastener; 
           [0031]      FIG. 24  is a cross-section view of a second embodiment of the fastener assembly showing the fastener retainer secured to an adjacent side panel on the bottom side of a first work piece and both the spring and a fastener bolt aligned on the top side of a second work piece secured together by the fastener; 
           [0032]      FIG. 25  is a cross section view of the second embodiment of the fastener assembly showing the fastener receptacle and the work piece; 
           [0033]      FIG. 26  is an exploded, perspective view of the five parts of the fastener bolt of the second embodiment; 
           [0034]      FIG. 27  is a perspective view of the assembled fastener bolt, showing a formed over flap at the top of the housing and contain the other parts of the assembly; and 
           [0035]      FIG. 28  is a cross-section view of a third embodiment of the fastener assembly showing the fastener retainer secured to the bottom side of a first work piece and both the spring and a fastener bolt aligned on the top side of a second work piece secured together by the fastener. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]    Referring to  FIGS. 1 to 3 , the quick lock fastener of this invention includes a receptacle  10  and a bolt  12 . The receptacle  10  is adapted to be irremovably attached to a first work piece  14 , such as a plate, housing or the like, having a generally planar upper and lower surface. The first work piece  14  includes a generally circular aperture  16  to receive the bolt  12 . The fastener is associated with and is attached to a second work piece  18 , such as a plate, housing or the like, also having generally upper and lower planar surfaces. The orientations used above, as well as below, of “upper” and “lower” is for convenience of description; any orientation can be substituted, e.g. right and left, or any angle. The second work piece also includes a generally circular aperture  20  to receive the bolt  12 . The bolt  12  is adapted to be releasably secured to the receptacle  10  to thereby releasably attach the second work piece  18  in locked engagement to the first work piece  14 . 
         [0037]    The work pieces may be formed from metallic and/or non-metallic materials including by way of example, but not limitation, steel, stainless steel, all steel alloys, aluminum, all aluminum alloys, titanium, all titanium alloys, plastic, and composite materials including graphite, carbon, quartz, glass, polymers, and cellulose. 
         [0038]    The receptacle  10  includes a generally plate like base member  22 . The base member  22  includes generally planar upper and lower surfaces and includes one or more apertures  24  for use in attaching the base member  22  to a surface of the first work piece  14  with fasteners  26 , such as threaded fasteners, rivets, and the like. 
         [0039]      FIG. 1  shows the receptacle  10  has a housing  28  that extends from the base member  22  and includes a generally cylindrical side wall  30 . The housing  28  includes an annular groove  32  formed in the interior of the side wall  30  generally parallel to the base member  22  to receive a biasing member, such as a bolt retaining ring  34 . The term “biasing member is meant to include any of a wide variety of biasing devices such as a retaining ring, snap ring or circlip, which are fasteners that lock a component in a receptacle when installed in a groove in the receptacle. The housing terminates in a generally planar and circular end wall  36  formed with an aperture  38  to receive the end of a tool, described below. The housing side wall  30  has helical apertures  40  formed in the side wall to form a machined integral spring of high strength. The receptacle  10  has an annular groove  41  formed in the exterior of the side wall  30  generally parallel to the base member  22  to receive a biasing member, such as an exterior retaining ring  42 . A co-axial sleeve  44  is located on the housing  28  between the exterior retaining ring  42  and the base member  22  to limit the spring compression travel. 
         [0040]    Referring additionally to  FIGS. 4 and 5 , the fastener includes the bolt  12  having a tubular and cylindrical body  46  with a central longitudinal axial opening  47  as shown in  FIG. 1  and a bolt head  48  at one end that is larger in diameter than the body  46 . The top surface of the bolt head  48  includes a counter bore  51  to the axial opening  47 . The side surface of the bolt head includes a receiving recess  52  for a lanyard  53 . A region of the bolt body  46  distal to the head  48  has an annular exterior groove  54  for receiving the bolt retaining ring  34  or other biasing member referred to above. The slot  50  in the top surface of the bolt head  48  extends to a cut-away section  56  of the bolt body  46  to enable a tool to access to the retaining ring  34  on the bolt body when the bolt is inserted into the receptacle  10  to thereby enable the retaining ring  34  to be locked into the internal receptacle groove  32 , as will be described further below. 
         [0041]    Referring additionally to  FIGS. 6 and 7 , the lanyard  53  is used in the receiving recess  52  to retain the fastener bolt  12  to the second work piece  18  for ease of assembly. The other end of the lanyard  53  is attached to the second work piece  18  with a fastener  23 , such as a threaded screw, rivet, or the like. The lanyard  53  is made of resilient material (i.e., spring steel) which lifts the fastener  12  axially a distance from the surface of the second work piece  18  when disengaged from the receptacle  10 . The raised position of the bolt indicates that the bolt is not fastened. 
         [0042]    Referring to  FIGS. 8-12  in conjunction with  FIGS. 3-5 , details concerning use of the bolt retaining ring  34  are shown.  FIG. 8  shows the retaining ring  34  in a relaxed state with no load applied while seated on the bolt body  46  prior to assembly of the fastener.  FIGS. 9 and 11  show the retaining ring  34  fully compressed while seated on the bolt body  46  to create a clearance fit between the receptacle groove  32  and the outside surface of the retaining ring during fastener assembly.  FIGS. 10 and 12  show the retaining ring  34  partially compressed by contact between the outer surface of the retaining ring  34  and the inner surface of the receptacle groove  32  at final fastener assembly. 
         [0043]    Referring additionally to  FIGS. 13-15 , details are shown of a jaw positioning tool  58 , shown schematically in  FIG. 13 , used to compress the ends of the bolt retaining ring  34  so as to secure the bolt  12  into the receptacle  10 . Referring specifically to  FIG. 13 , the tool  58  has a pair of jaws  60  and  62  with pin tips  64  and  66  ( FIGS. 11 and 12 ) that can engage respective receiving holes  68  and  70  in the free ends of the retaining ring  34  (see  FIGS. 8-12 ) and can be drawn inward to compress the retaining ring  34  with the minimum outside diameter to enable the bolt  12  to be inserted into the receptacle  10  and then to spread apart the retaining ring  34  so that it locks into the internal receptacle groove  32  (see  FIG. 1 ). The jaw positioning tool  58  comprises a jack screw formed with a pair of opposing support columns  72  and  74  for opposing guide pins  76  and  78 , a left hand threaded shaft  80  and a right hand threaded shaft  82  positioned through a pair of opposing support members  84  and  86  that support the respective jaws  60  and  62 . A centered jaw spread lever  88  rotates the shafts  80  and  82  and moves the support members  84  and  86 , hence moves the jaws  60  and  62  and tips  64  and  66 , apart and together. 
         [0044]      FIG. 14  shows details of a base component  90  and its plunger  91  of the tool  58 . The retractable plunger engages a counter bore  57  in the side of the bolt head as shown  FIG. 1 . The tool base  90  boss surface  94  shown in  FIG. 14  mates with the counter bore  51  ( FIGS. 1 and 5 ) on the top of the bolt head. 
         [0045]    Referring additionally to  FIGS. 15-23 , more details of the jaw positioning tool  58  in relation to the bolt and receptacle are shown. The jaw positioning tool  58  is used to load and lock the fastener bolt  12  to the fastener receptacle  10 .  FIG. 15  shows the tool  58  at its initial lever setup. In  FIGS. 16-23 , the tool  58  has seven lever setups which occur sequentially to fasten the assembly. The first setup is to place the lever positions into the initial position on the tool as shown in  FIG. 16 . The retractable plunger  91  in the base  90  is retracted, the jaw spread lever  88  is set for an uncompressed retainer ring, the clamp end  93  is vertically directed, and the clamp  92  is extended. In another step, shown in  FIG. 17 , the tool  58  is attached to the fastener  12  by means of mating the counter bore surface located on the fastener top with the tool base  90 , then the retractable plunger  92  extends to insert into the counter bore located on the side of the bolt head. Referring back to  FIG. 13 , the tool pins  64  and  66  are inserted into the fastener retaining ring lug end holes as shown in  FIG. 8 . In a next step, as shown in  FIG. 18 , the tool  58  with fastener  12  attached is inserted through work pieces  14  and  18  and receptacle  10 . The jaw spread lever  88  is rotated to move the pins inward to the position as shown in  FIG. 9  to compress the retaining ring  34 . In the next step, the clamp end lever  93  is rotated so that the clamp end is horizontally directed as shown in  FIG. 19 . Next, the clamp lever  92  moves to retract the clamp end as shown in  FIG. 20 . Then, as shown in  FIG. 21 , the jaw spread lever  88  moves to expand the retaining ring  34  as shown in  FIG. 10  and release it into the receptacle groove and secure bolt to the receptacle. To remove the tool  58 , as shown on  FIG. 2 , the clamp lever  92  moves to extend the clamp end and release the external clamp load on the receptacle, then the clamp angle lever rotates to align the clamp end axially as shown in  FIG. 23 , the retractable plunger  91  retracting to release the fastener. 
         [0046]    Recapping,  FIG. 16  shows the tool  58  and fastener bolt  12  positioned for insertion of the tool  58  into the fastener bolt  12  with the clamp lever  92  extended, the position of the clamp end lever  93  at a vertically directed angle, the jaw spread lever  88  position aligns for free state retaining ring  34 , and the plunger  91  of the base  90  retracts to allow clearance to attach fastener  12 .  FIG. 17  shows the tool  58  fully inserted into the fastener bolt  12  with the jaw spread lever  88  uncompressing the bolt retaining ring  34  as shown in  FIG. 8  to engage the pin ends  66  and  64 . The plunger  91  of the base  90  extends to engage the counter bore on the side of the bolt head and secure the fastener  12  to the tool  58 .  FIG. 18  shows the tool  58  fully inserted into the fastener, secured across first and second work pieces  14  and  18  with the clamp end rotating lever  93  at a vertically directed angle, the jaw spread lever  88  compressing the bolt retaining ring  34  as shown in  FIG. 9  for retaining ring clearance inside the receptacle  10 .  FIG. 19  also shows the tool  58  fully inserted into the fastener, secured across first and second work pieces  14  and  18  with the jaw rotating lever  93  at a horizontally directed angle and locked in place by the extended plunger  92  for safety.  FIG. 20  shows the fully inserted tool as in  FIG. 19  but with the clamp lever  92  rotated to compress the receptacle  10  and work pieces  14  and  18  against the fastener  12 .  FIG. 21  shows the fully inserted tool as in  FIG. 20  but with jaw spread lever  88  in a position that lowers the compression and releases the retaining ring  34  as shown in  FIG. 10  into the adjacent receptacle groove for final assembly.  FIG. 22  shows the fully inserted tool as in  FIG. 21  but with the clamp lever  92  extended to unload the fastener.  FIG. 23  shows the fully inserted tool as in  FIG. 22  but with the position of the clamp end lever  93  rotated to from horizontally directed to vertically directed and the plunger  91  of the base  90  retracted to enable the tool  58  to be removed from the fastener. 
         [0047]    Referring to  FIG. 24 , a second embodiment of the invention is shown where many of the individual components are the same as  FIG. 1 , but where the fastener receptacle  210  is secured to an adjacent side panel on the interior side of the first work piece  214  and both the spring  230  and fastener bolt  212  are aligned on the top side of the second work piece  218  secured together by the fastener. 
         [0048]      FIG. 25  shows the second embodiment of the receptacle  210  adapted to be irremovably attached to a first work piece  214  as in  FIG. 3 , but the first work piece  214  in the second embodiment is oriented perpendicular to the second work piece. 
         [0049]      FIG. 26  shows a second embodiment of the invention where individual parts are shown as part of the bolt assembly instead of as part of the receptacle assembly in  FIG. 2 . A formable cup  253  holds the individual pieces of the bolt assembly. 
         [0050]      FIG. 27  shows the second embodiment of the invention where the top end of the cylindrical wall of the cup  253  is formed over to create a flange  255  which covers the fastener bolt The bottom end of the cylindrical wall of the cup  253  is formed over and irremovably attaches to the second work piece  218  similar to the purpose of the lanyard  53  in  FIG. 6 . 
         [0051]      FIG. 28  shows a third embodiment of the invention where many of the parts are similar to  FIG. 24 , but where the receptacle  310  is secured to the bottom of the first work piece  314  in a manner similar to  FIG. 1 . 
         [0052]    Although the present invention has been described in connection with the preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the principles and scope of the invention, as those skilled in the art will readily understand. Accordingly, such modifications may be practiced within the scope of the following claims.