Patent Publication Number: US-2004052612-A1

Title: Fastener

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT  
       [0001] The present invention relates to a fastener for attaching a component to a body of an automobile or a panel of a main member of an electric equipment, or for attaching a panel to another panel.  
       [0002] A conventional fastener is composed of a head portion; an engagement leg including multiple elastic engagement pieces providing projections on an outer face of elastic pieces projecting from the head portion at the middle in the vertical direction; and an elastic seal portion provided between the engagement leg and the head portion (for example, refer to Japanese Patent Publication (TOKKAI) No. 05-164120).  
       [0003] When the engagement leg of the fastener is pressed into an attaching hole formed in a panel as an attached member from a lower end, an inner portion of the attaching hole presses the multiple elastic pieces through the projections. Accordingly, the multiple elastic pieces deform inwardly, and the engagement leg can be inserted into the attaching hole until the elastic seal portion abuts against a surface of the panel.  
       [0004] When the engagement leg is inserted into the attaching hole until the elastic seal portion abuts against the surface of the panel, the multiple elastic engagement pieces try to return to the former state by the elasticity. An upper end of the projection provided on each elastic piece abuts against a backside of the panel or a backside edge of the attaching hole, so that a rim of the elastic seal portion and the multiple projections support the panel, thereby attaching the fastener to the panel.  
       [0005] In the conventional fastener, the projections have the same height. In other words, a distance, i.e. supportable distance, between the rim of each projection and the rim of the elastic seal portion deformed slightly upward is all the same. Therefore, the conventional fastener can hold a panel having a thickness within only a certain range. Accordingly, when the fastener is attached to a panel having a thickness out of the range, it is necessary to use a different fastener.  
       [0006] The present invention is proposed in order to solve the above-mentioned problems, and an object of the present invention is to provide a fastener capable of being attached to a member having a thickness with one of at least two ranges.  
       [0007] Further objects and advantages of the invention will be apparent from the following description of the invention.  
       SUMMARY OF INVENTION  
       [0008] According to the present invention, a fastener includes a head portion and an engagement leg. The engagement leg is formed of elastic pieces projecting from the head portion and a plurality of elastic engagement pieces having projections formed on outer faces of the elastic pieces at the middle in a vertical direction. Further, each projection has a height different from that of an adjacent projection. It is preferable that a projection has a height same as that of a projection located at a diagonal position. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009]FIG. 1 is a front view of a fastener according to the present invention;  
     [0010]FIG. 2 is a plan view of the fastener according to the present invention;  
     [0011]FIG. 3 is a bottom view of the fastener according to the present invention;  
     [0012]FIG. 4 is a left side view of the fastener according to the present invention;  
     [0013]FIG. 5 is a cross sectional view taken along line  5 - 5  in FIG. 1;  
     [0014]FIG. 6 is a partial cross sectional view taken along line  6 - 6  in FIG. 3;  
     [0015]FIG. 7 is a view showing a state where the fastener of the present invention is used; and  
     [0016]FIG. 8 is a view showing the state where the fastener of the present invention is used. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
     [0017] Hereinafter, embodiments of the present invention will be explained with reference to the accompanying drawings. FIG. 1 is a front view of a fastener of the present invention. FIG. 2 is a plan view of the fastener of the present invention. FIG. 3 is a bottom view of the fastener of the present invention. FIG. 4 is a left side view of the fastener of the present invention. FIG. 5 is a cross sectional view taken along line  5 - 5  in FIG. 1, and FIG. 6 is the cross sectional view taken along line  6 - 6  in FIG. 3. The rear view is the same as the front view, and the right side face view is the same as the left side face view. In FIGS. 5 and 6, phantom lines indicate elastic pieces and projections of elastic engagement pieces.  
     [0018] As shown in FIG. 1, a fastener  1  is formed of a synthetic resin. The fastener  1  includes a head portion  11 ; an engagement leg  21  including multiple elastic engagement pieces  26 A,  26 B having projections  28 A,  28 B formed at the middle in the vertical direction on outer faces of elastic pieces  27 A,  27 B projecting from the center of a lower side of the head portion  11 ; and an elastic seal portion  31  provided between the engagement leg  21  and the head portion  11 .  
     [0019] As shown in FIG. 2, the head portion  11  is composed of an upper collar  12  having a circular shape and a predetermined outer diameter; a neck portion  13  having a diameter smaller than the outer diameter of the upper collar  12  and projecting at the center of a lower surface of the upper collar  12 ; and a lower elastic collar  14  having a diameter larger than the upper collar  12 . The lower elastic collar  14  is formed around the neck portion  13  at a lower outer periphery thereof, and has a waving surface lowering after rising toward the upper collar  12  from an inner periphery to an outer periphery as shown in FIG. 6. As shown in FIGS. 2 and 6, a depression  15  extending from the upper collar  12  to the lower elastic collar  14  is provided at the center of the neck portion  13 .  
     [0020] As shown in FIGS. 5 and 6, the engagement leg  21  is composed of an axial core portion  22  projecting at the center of the lower side of the head portion  11 ; and elastic engagement pieces  26 A,  26 B projecting from the lower side of the head portion  11  and formed along the axial core portion  22  between the projected pieces  24  of the axial core portion  22 .  
     [0021] As shown in FIGS. 1 and 3- 5 , the axial core portion  22  is composed of an axial core  23  projecting at the center of the lower side of the head portion  11 ; four projected pieces  24  formed on the peripheral face of the axial core  23  along the axial direction and shifted 90 degrees with each other; and two connecting portions  25 , each connecting a pair of the elastic engagement pieces  26 A,  26 B and the lower portion of the projected piece  24  located between the elastic engagement pieces  26 A,  26 B. The elastic engagement pieces  26 A,  26 B having a fan-shaped cross section are alternately disposed one by one between the four projected pieces  24  as shown in FIGS. 3 and 5.  
     [0022] As shown in FIGS. 3, 5, and  6 , the elastic engagement pieces  26 A,  26 B are composed of two elastic pieces  27 A,  27 B located between the projected pieces  24  below the head portion  11 ; and projections  28 A,  28 B provided on the outer faces of the elastic pieces  27 A,  27 B at the middle in the vertical direction. The elastic pieces  27 A,  27 B are connected at lower portions thereof through the connecting portions  25 . As shown in FIGS. 1 and 6, the projections  28 A (or the projections  28 B) located at the diagonal positions (axial symmetry positions) have the same height. The adjacent projections  28 A and  28 B have different heights. In other words, an interval (supportable interval) La between a rim of the elastic seal portion  31  deformable slightly upward and a rim of the projections  28 A is smaller than an interval (supportable interval) Lb between a rim of the elastic seal portion  31  and a rim of the projections  28 B.  
     [0023] A circle connecting the outer faces of the four projected pieces  24  and the elastic pieces  27 A,  27 B has a diameter smaller than those of the attaching holes  52 ,  54  of panels  51 ,  53  (described later). A circle connecting the outer faces of the four projections  28 A,  28 B has a diameter larger than those of the attaching holes  52 ,  54  of the panels  51 ,  53 .  
     [0024] Furthermore, an upper end of each projection  28 A,  28 B has a face declining toward outside (declining face expanding downwardly). Also, a gap (slit, etc.) is provided between the axial core portion  22  and the elastic engagement pieces  26 A,  26 B for allowing the elastic engagement pieces  26 A,  26 B to bend inwardly. A lower end part of the engagement leg  21  is formed in a cone shape reducing downwardly. A guide face is provided on a lower end part of the engagement leg  21 .  
     [0025] As shown in FIGS. 2 and 6, the elastic seal portion  31  has a circular cone face declining outwardly, and a circular shape with a diameter larger than the lower elastic collar  14 .  
     [0026]FIGS. 7 and 8 are views showing states where the fastener of the first embodiment of the present invention shown in FIGS.  1 - 6  is used. In FIGS.  7  or  8 , the circular attaching holes  52 ,  54  for attaching the fastener  1  are provided in the panels  51 ,  53  as members to be attached. The panel  51  has a thickness that the fastener  1  can be attached by using the projections  28 A of the elastic engagement pieces  26 A. The panel  53  has a thickness that the fastener  1  can be attached by using the projections  28 B of the elastic engagement pieces  26 B.  
     [0027] A keyhole  62  to be attached to the fastener  1  is provided in an attaching panel  61  as an attaching member. The keyhole  62  includes a circular through-hole  63  having a diameter larger than the upper collar  12  and smaller than the lower elastic collar  14 , and an oval engagement hole  64  having a diameter slightly larger than the neck portion  13  and smaller than the upper collar  12 .  
     [0028] A process of attaching the attaching panel  61  to the panel  51  using the fastener  1  will be explained next. First, the end of the engagement leg  21  faces the panel  51 , and the engagement leg  21  is pressed into the attaching hole  52  from the end. Accordingly, an inside portion of the attaching hole  52  presses the elastic pieces  27 A,  27 B through the projections  28 A,  28 B, so that the elastic engagement pieces  26 A,  26 B deform inwardly. As a result, the engagement leg  21  is inserted into the attaching hole  52  until the elastic seal portion  31  abuts against a surface of the panel  51 .  
     [0029] When the engagement leg  21  is inserted into the attaching hole  52  until the elastic seal portion  31  abuts against the surface of the panel  51 , the elastic engagement pieces  26 B located at axial symmetric positions expand to restore the former state with the elasticity of the elastic pieces  27 B. The elastic engagement pieces  26 A located at axial symmetric positions try to enlarge with the elasticity of the elastic pieces  27 A. The upper ends of the projections  28 A provided on the elastic pieces  27 A abut against the backside edge of the attaching hole  52 . As shown in FIG. 7, the rim of the elastic seal portion  31  and the two projections  28 A sandwich the panel  51 . Accordingly, the fastener  1  is attached to the panel  51 . In the case where the fastener  1  is attached to the panel  51 , the upper ends of the two projections  28 B are located away from the backside edge of the attaching hole  52 , thereby not supporting the panel  51 .  
     [0030] Next, the upper collar  12  is passed through the through-hole  63  of the keyhole  62 . Then, the attaching panel  61  is shifted to move the neck portion  13  into the engagement hole  64 . The neck portion  13  abuts against the back edge of the engagement hole  64 . Then, the attaching panel  61  is fixed to the panel  51  with, for example, an attaching screw, so that the attaching panel  61  is attached to the panel  51 . In a case that the attaching panel  61  is attached in a suspended state, the attaching panel  61  is moved below the fastener  1  attached in a horizontal position, and the neck portion  13  abuts against the back edge of the engagement hole  64 , so that the attaching panel  61  is attached in the suspended state.  
     [0031] A process of attaching the attaching panel  61  to the panel  53  using the fastener  1  will be explained next. First, the end of the engagement leg  21  faces the panel  53 , and the engagement leg  21  is pressed into the attaching hole  54  from the end. The inside part of the attaching hole  54  pushes the elastic pieces  27 A,  27 B through the projections  28 A,  28 B, so that the elastic engagement piece  26 A,  26 B deform inwardly. As a result, the engagement leg  21  is inserted into the attaching hole  54  until the elastic seal portion  31  abuts against the surface of the panel  53 .  
     [0032] When the engagement leg  21  is inserted into the attaching hole  54  until the elastic seal portion  31  abuts against the surface of the panel  53 , the elastic engagement pieces  26 B located at the axial symmetric positions try to expand with the elasticity of the elastic pieces  27 B. The upper ends of the projections  28 B provided on the elastic pieces  27 B abut against the backside edge of the attaching hole  54 . As a result, as shown in FIG. 8, the rim of the elastic seal portion  31  and the projections  28 B sandwich the panel  53 . Accordingly, the fastener  1  is attached to the panel  53 . When the fastener  1  is attached to the panel  53 , the inside part of the attaching hole  54  keeps pushing the two projections  28 A, and the two elastic engagement pieces  26 A remain deformed inwardly, so that the two projections  28 A do not contribute to support the panel  53 . After that, the attaching panel  61  is fixed to the panel  53  with the method mentioned above.  
     [0033] According to the present invention, the adjacent projections  27 A,  27 B have different heights. Therefore, the attaching panel  61  can be attached to the panels  51 ,  53  having thicknesses within the two permissible ranges by using the fastener  1 . The projections  28 A (or  28 B) located at the diagonal positions have the same height, so that the fastener  1  can be firmly attached to the panel  51  (or  53 ).  
     [0034] In the present embodiment, the fastener is provided with four projected pieces  24 , two respective elastic engagement pieces  26 A,  26 B, and two respective projections  28 A,  28 B. It is possible that an even number (more than two) of the projected pieces is provided (or not provided at all), and an even number (more than two) of the elastic engagement pieces is provided. In this case, the adjacent projections may have different heights, or the projections at the diagonal positions may have the same height. Alternatively, it is possible that more than two of the projected pieces are provided (or not provided at all), and more than two of the elastic engagement pieces are provided. In this case, the adjacent projections may have different heights. With the above-mentioned configurations, the fastener can be attached to the attached members having thicknesses within at least two permissible ranges.  
     [0035] In the embodiment, the projections  28 A,  28 B at the diagonal positions have the same height. It is also possible that the projections at the diagonal positions have different heights. Furthermore, in the embodiment, the projections  28 A (or  28 B) and the elastic seal portion  31  support the panels  51  (or  53 ). Alternatively, the elastic seal portion  31  may be omitted. In this case, the head portion  11  (lower elastic collar  14 , or simply lower collar) and the projections  28 A (or  28 B) support the panels  51  (or  53 ).  
     [0036] According to the present invention, the adjacent projections have the different heights. Therefore, the fastener can be attached to the attached members having thicknesses within at least two permissible ranges. The projections at the diagonal positions have the same height, so that the fastener can be firmly attached to the attached members.  
     [0037] While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.