Abstract:
A two part fastener ( 10 ) for clamping together first and second members ( 20, 22 ) that have an opening ( 40 ). The fastener ( 10 ) comprises a base ( 12 ) having a plurality of legs ( 80, 90 ) resiliently biased outwardly away from each other and insertable through the opening ( 40 ). A knob ( 14 ) connected with the base ( 12 ) is manually rotatable relative to the base to control the position of the legs ( 80, 90 ). The knob ( 14 ) has a first position of rotation relative to the base ( 12 ) in which blocking portions ( 80, 90 ) of the legs are in a blocking position to block removal of the legs through the opening ( 40 ). In a second position of rotation the knob ( 14 ) blocks inward movement of the blocking portions ( 88, 98 ) of the legs ( 80, 90 ) from the blocking position, thereby blocking removal of the fastener  10 . In a third position of rotation the knob ( 14 ) holds the blocking portions ( 88, 98 ) of the legs ( 80, 90 ) inward from the blocking position, thereby enabling removal of the fastener ( 10 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a two part twist fastener for releasably securing a first member to a second member. 
     2. Description of the Prior Art 
     In many applications it is necessary to fasten together two members, such as panels or plates, in a releasable manner. For example, a vehicle door typically includes at least two panels that must be fastened securely together, but must also be removable from each other. Many different types of releasable fasteners have been developed for this type of application. 
     SUMMARY OF THE INVENTION 
     The present invention is a two part fastener for clamping together first and second members in an overlying relationship. The first and second members have surfaces defining an opening extending through the first and second members. The fastener comprises a base insertable into the opening. The base has a plurality of legs resiliently biased outwardly away from each other and movable between a plurality of positions relative to the first and second members. The legs are insertable through the opening. The fastener also comprises an actuator connected with the base and manually rotatable relative to the base to control the position of the legs of the base relative to the first and second members. The actuator has a first position of rotation relative to the base in which blocking portions of the legs are in a blocking position to block removal of the legs through the opening. The actuator has a second position of rotation relative to the base in which the actuator blocks inward movement of the blocking portions of the legs from the blocking position, thereby blocking removal of the fastener through the opening. The actuator has a third position of rotation relative to the base in which the actuator holds the blocking portions of the legs inward from the blocking position, thereby enabling removal of the fastener from the first and second members through the opening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view of a fastener in accordance with the invention; 
     FIG. 2 is an exploded sectional view of the fastener of FIG. 1, taken generally along line  2 — 2  of FIG. 1; 
     FIG. 3 is a top plan view of the fastener of FIG. 1, shown in a first condition; 
     FIG. 4 is a sectional view taken generally along line  4 — 4  of FIG. 1 showing the fastener in a first condition for insertion into an opening of members to be fastened together; 
     FIG. 5 is a sectional view taken generally along line  5 — 5  of FIG. 4 showing parts of the fastener in the first condition; 
     FIG. 6 is a top plan view of the fastener of FIG. 1, similar to FIG. 3, showing the fastener in a second or locking condition; 
     FIG. 7 is a sectional view similar to FIG. 4 showing the fastener in the second or locking condition; 
     FIG. 8 is a sectional view similar to FIG. 5 showing parts of the fastener in the second condition; 
     FIG. 9 is an enlarged view of a portion of FIG. 7; 
     FIG. 10 is a top plan view of the fastener of FIG. 1, similar to FIG. 3, showing the fastener in a third or release condition; 
     FIG. 11 is a sectional view similar to FIG. 4 showing the fastener in the third or release condition; and 
     FIG. 12 is a sectional view similar to FIG. 5 showing parts of the fastener in the third condition. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to a two part twist fastener for releasably securing a first member to a second member. The present invention is applicable to different fastener constructions. As representative of the present invention, FIG. 1 illustrates a two-part fastener  10  in accordance with the invention. The fastener includes a base  12  and a knob  14 . 
     The fastener is used for releasably securing together two or more members in an overlying relationship. In the illustrated embodiment, the fastener is used for releasably securing together a first member  20  (FIG. 4) and a second member  22 . The first and second members  20  and  22  may be, for example, portions of a vehicle door, such as a support panel and a trim panel, or may be two plates or other pieces. 
     The first member  20  (FIG. 4) has opposite inner (that is, away from the side of entry of the fastener, or to the bottom as viewed in FIG. 4) and outer major side surfaces  26  and  28 . The first member  20  has a rectangular slot  30  extending between the inner and outer major side surfaces  26  and  28 . The second member  22  has opposite inner and outer major side surfaces  32  and  34 . The inner major side surface  32  of the second member  22  is in abutting engagement with the outer major side surface  28  of the first member  20 . 
     The second member  22  (FIG. 4) has a rectangular slot  36  extending between the inner and outer major side surfaces  32  and  34 . The slot  36  in the second member  22  is preferably similar or identical in configuration to the slot  30  in the first member. The slot  36  in the second member  22  overlies the slot  30  in the first member  20  and together they form an opening  40  in the two members  20  and  22 . The opening  40  has a width extending between first and second edge surfaces  42  and  44  (FIG.  5 ), and a length extending between third and fourth edge surfaces  46  and  48 . The fastener  10  extends into the opening  40  in a manner described below to clamp the first member  20  to the second member  22 . 
     The base  12  (FIGS. 1 and 2) of the fastener  10  is preferably molded as one piece from a plastic material, but could alternatively be made from a different material or in a different manner. The base  12  includes a planar, disk-shaped main body portion  50  centered on an axis  118 . The main body portion  50  has an outer major side surface  52  (FIG. 2) and an inner major side surface  54 . The main body portion  50  also has two rectangular openings  56  and  58  spaced apart from each other. 
     The outer periphery of the main body portion  50  has an inwardly facing shoulder  60 , for engagement by the knob  14  in a manner described below. The main body portion  50  also has an outwardly facing shoulder  62 , for engagement by the knob  14  in a manner described below. 
     The base  12  includes a retainer assembly  70  that depends from the main body portion  50  and that is movable into the opening  40  in the first and second members  20  and  22 , as described below. The retainer assembly  70  includes two guide plates  72  and  74  that depend from the main body portion  50  on opposite sides of the two openings  56  and  58 . The retainer assembly  70  also includes a central support post  76  that depends from the main body portion  50  between the two openings  56  and  58 . The support post  76  has a rectangular cross-sectional configuration terminating in a curved lower end portion  78  for ease of insertion into the slot opening  40 . 
     The retainer assembly  70  further includes two engagement members  80  and  90  for engaging the inner side surface  26  of the first member  20 . The two engagement members  80  and  90  are formed as resilient retaining legs that extend from the lower end portion  78  of the central support post  76 , in a direction toward the main body portion  50  of the base  12 . The two retaining legs  80  and  90  are mirror images of each other, and are resiliently biased outward, away from each other. 
     The first retaining leg  80  is resiliently supported on the central support post  76 . The first retaining leg  80  has a base portion  82  that extends upward and outward from the lower end portion  78  of the support post  76 . The base portion  82  has a rectangular cross-sectional configuration. The base portion  82  has a cam surface  84  that faces outward away from the support post  76 . 
     The first retaining leg  80  has an upper end portion  86  that extends upward from the base portion  82 . The upper end portion  86  extends past the plane of the main body portion  50  and through the opening  56  in the main body portion. The upper end portion  86  has a kidney-shaped cross-sectional configuration (FIG.  5 ). 
     The first retaining leg  80  also has a blocking portion or blocking surface  88  (FIG. 2) that extends between the upper end portion  86  and the cam surface  84  of the base portion  82 . The blocking surface  88  faces outward, that is, away from the central support post  76 . 
     The second retaining leg  90  is a mirror image of the first retaining leg  80 . The second retaining leg  90  is resiliently supported on the central support post  76 . The second retaining leg  90  has a base portion  92  that extends upward and outward from the lower end portion  78  of the support post  76 . The base portion  92  has a rectangular cross-sectional configuration. The base portion  92  has a cam surface  94  that faces outward away from the support post  76 . 
     The second retaining leg  90  has an upper end portion  96  that extends upward from the base portion  92 . The upper end portion  96  extends past the plane of the main body portion  50  and through the opening  58  in the main body portion. The upper end portion  96  has a kidney-shaped cross-sectional configuration. 
     The second retaining leg  90  also has a blocking portion or blocking surface  98  that extends between the upper end portion  96  and the cam surface  94  of the base portion  92 . The blocking surface  98  faces outward, that is, away from the central support post  76 . 
     The knob  14  (FIGS. 1 and 2) is preferably molded as one piece from the same plastic material as the base  12 , but could alternatively be made from a different material or in a different manner. The knob  14  includes a planar, disk-shaped main body portion  110  having opposite inner and outer major side surfaces  112  and  114 . A rib-shaped finger grip  116  projects from the outer side surface  114  of the main body portion  110 . The finger grip  116  is manually engageable to effect rotation of the knob  14  about an axis  118  relative to the base  12 . 
     The knob  14  has an annular, outer peripheral rim  120  that extends from the main body portion  110 . Three snap retainers  122  extend from the rim  120 . The snap retainers  122  are engageable with the base  12 , in a manner described below, to retain the knob  14  on the base. 
     Two identical tracks  130  and  160  are formed on the inner major side surface  112  of the main body portion  110  of the knob  14 . The tracks  130  and  160  are in the form of curved ridges or ribs that project from the inner major side surface  112 . 
     The first track  130  (FIG. 5) has an overall L-shaped configuration including a first arm  132  and a second arm  134  that extends generally perpendicular to the first arm  132 . The first arm  132  has an inner side surface  136  facing the axis  118 , and an opposite outer side surface  138 . 
     The second arm  134  has an inner side surface  140  that is a continuation of the inner side surface  136  of the first arm  132  and that also faces the axis  118 . The second arm  134  jogs inward at  142 , so that an end portion  144  of the second arm is located radially inward of the remainder of the second arm. The end portion  144  has an outer side surface  148 . The end portion  144  terminates in a curled end  150  of the first track  130 . 
     At the location of the jog  142 , the second arm  134  has a stop rib  152  that projects outward. The stop rib  152  has a stop surface  154  that faces away from the first arm  132  and toward the end portion  144  of the second arm  134 . The stop surface  154  extends generally perpendicular to the end portion  144  of the second arm  134  and to the outer side surface  148  of the end portion. 
     The second track  160  has the same configuration as the first track  130  but is located 180 degrees circumferentially about the axis  118  from the first track. The second track  160  has an overall L-shaped configuration including a first arm  162  and a second arm  164  that extends generally perpendicular to the first arm. 
     The first arm  162  has an inner side surface  166  facing the axis  118 , and an opposite outer side surface  168 . The second arm  164  has an inner side surface  170  that is a continuation of the inner side surface  166  of the first arm  162  and that also faces the axis. The second arm  164  jogs inward at  172 , so that an end portion  174  of the second arm is located radially inward of the remainder of the second arm. The end portion  174  has an outer side surface  178 . The end portion  174  terminates in a curled end  180  of the second track  160 . 
     At the location of the jog  172 , the second arm  164  has a stop rib  182  that projects outward. The stop rib  182  has a stop surface  184  that faces away from the first arm  162  and toward the end portion  174  of the second arm  164 . The stop surface  184  extends generally perpendicular to the end portion  174  of the second arm  164  and to the outer side surface  178  of the end portion. 
     The first and second tracks  130  and  160  are positioned on the knob  14  so that each is engageable with the end portions  86  and  96  of the first and second retaining legs  80  and  90 , respectively, of the base  12 , in a manner described below, when the knob is rotated to different positions relative to the base. 
     The fastener  10  is assembled by snapping the knob  14  onto the base  12 . The snap retainers  122  (FIGS. 7 and 9) on the knob  14  engage the shoulder  60  of the base  12  to block removal of the knob from the base. The knob  14  is supported on the base  12  for rotation relative to the base about the axis  118 . The knob  14  and base  12  are both symmetrical about the axis  118 , so that the knob can be assembled to the base in either of two starting positions 180 degrees apart. 
     When the knob  14  is assembled on the base  12 , and prior to insertion of the fastener  10  into the opening  40 , the parts of the fastener are in an assembled condition shown in FIG.  4  and in solid lines in FIG.  5 . The first retaining leg  80  is biased outwardly and engages the inner side surface  136  of the first arm  132  of the first track  130 . The second retaining leg  90  is biased outwardly and engages the inner side surface  166  of the first arm  162  of the second track  160 . 
     When the fastener  10  is thereafter inserted into the opening  40  in the first and second members  20  and  22 , the parts of the fastener assume a first condition, or insertion condition. In the first condition, the parts of the fastener  10  are in substantially the same position as in the assembled condition shown in FIG.  4  and in solid lines in FIG. 5, with the exception that the retaining legs  80  and  90  move inwardly, away from the tracks  130  and  160 , into the position shown in dashed lines in FIG.  5 . 
     Specifically, as the retainer assembly  70  of the fastener  10  is inserted into the opening  40  (shown in dashed lines in FIG.  5 ), the cam surfaces  84  and  94  on the retaining legs  80  and  90 , respectively, engage the edge surfaces  46  and  48  of the opening  40 , and cam the retaining legs inward from their as-molded condition, toward the axis  118 . 
     The fastener  10  moves axially into the opening  40  until the inner side surface  54  of the main body portion  50  of the base  12  engages the outer side surface  34  of the second member  22 , as shown in FIG. 12, to limit axial movement of the fastener in a direction into the opening. 
     During this movement, the retainer assembly  70  moves far enough into the opening  40  that the blocking surfaces  88  and  98  move past the edge surfaces  46  and  48 . The retaining legs  80  and  90  spring back outward, away from the axis  118 . The retaining legs  80  and  90  move outward until the end portions  86  and  96  of the retaining legs engage the edge surfaces  46  and  48  of the opening  40 . The edge surfaces  46  and  48  of the opening  40  resist further lateral movement of the retaining legs  80  and  90 . The blocking surface  88  on the first retaining leg  80  and the blocking surface  98  on the second retaining leg  90  engage the inner major side surface  26  of the first member  20 . This engagement blocks or resists removal of the base  12  from the opening  40 . 
     The blocking portions  88  and  98  of the legs  80  and  90  are thus in a blocking position to block removal of the legs through the opening  40 . The retaining legs  80  and  90  can, however, be forced to bend inward to enable removal of the fastener  10  from the opening  40 , if sufficient axial force is placed on the fastener. Therefore, the fastener  10  is not locked, and the members  20  and  22  are not securely clamped together. 
     To move the fastener  10  from the first condition to a second or locking condition, the knob  14  is rotated about 90 degrees relative to the base  12  in a first direction, as shown by the “LOCK” arrow in FIG.  6 . When rotational force is placed on the finger grip  116  of the knob  14 , the knob rotates relative to the base  12 , but the base does not rotate in the opening  40  because of the engagement of the retaining legs  80  and  90  in the opening. 
     As the knob  14  rotates relative to the base  12 , the first and second tracks  130  and  160  on the knob rotate relative to the retaining legs  80  and  90  of the base, in a counter-clockwise direction as viewed in FIG. 8 from the position shown in FIG. 5 to the position shown in FIG.  8 . The first track  130  rotates away from the first retaining leg  80 , and into engagement with the second retaining leg  90 . Simultaneously, the second track  160  rotates away from the second retaining leg  90 , and into engagement with the first retaining leg  80 . 
     Specifically, the end portion  144  of the second arm  134  of the first track  130  engages the end portion  96  of the second retaining leg  90 . The second arm  134  of the first track  130  slides along the second retaining leg  90  to a rotational position radially inward of the end portion  96  of the second retaining leg. The stop surface  154  on the stop rib  152  of the second arm  134  of the first track  130  engages the second retaining leg  90  to stop rotational movement of the knob  14 . In this position of the parts, the first track  130  blocks inward movement of the end portion  96  of the second retaining leg  90 , while the edge surface  46  or  48  of the opening  40  blocks outward movement of the second retaining leg. 
     Simultaneously, the end portion  174  of the second arm  164  of the second track  160  engages the end portion  86  of the first retaining leg  80 . The second arm  164  of the second track  160  slides along the first retaining leg  80  to a rotational position radially inward of the end portion  86  of the first retaining leg. The stop surface  184  on the stop rib  182  of the second arm  164  of the second track  160  engages the first retaining leg  80  to stop rotational movement of the knob  14 . In this position of the parts, the second track  160  blocks inward movement of the end portion  86  of the first retaining leg  80 , while the edge surface  48  or  46  of the opening  40  blocks outward movement of the first retaining leg. 
     Thus, when the knob  14  is rotated to place the fastener  10  in the second or locked condition shown in FIGS. 6-8, the blocking portions  88  and  98  of the retaining legs  80  and  90 , respectively, are in a blocking position (FIG.  7 ). The legs  80  and  90  are blocked from inward movement by the tracks  130  and  160  (FIG.  8 ), and are blocked from outward movement by the edge surfaces  46  and  48  of the opening  30 . As a result, the retaining legs  80  and  90  are locked in the position shown in FIGS. 7 and 8. In this position, the retaining legs  80  and  90  can not be moved to a position to allow removal of the base  12  from the opening  40 . Therefore, the retaining legs  80  and  90  block removal of the fastener  10  from the opening  30 , and the first and second members  20  and  22  are clamped together. 
     To move the fastener  10  from the first condition to a third or release condition, the knob  14  is rotated about 90 degrees relative to the base  12  in a second direction opposite the first direction, as shown by the “OPEN” arrow in FIG.  10 . (Alternatively, if the fastener  10  is in the locked condition, the knob  14  is rotated 180 degrees to move the fastener to the release condition). 
     As the knob  14  rotates relative to the base  12 , the first and second tracks  130  and  160  on the knob rotate relative to the retaining legs  80  and  90  of the base, in a clockwise direction as viewed in FIG. 12 from the position shown in FIG. 5 to the position shown in FIG.  12 . The first track  130  stays in engagement with the end portion  86  of the first retaining leg  80 . The second track  160  stays in engagement with the end portion  96  of the second retaining leg  90 . 
     Specifically, the inner side surface  140  of the second arm  134  of the first track  130  engages the end portion  86  of the first retaining leg  80 . The second arm  134  of the first track  130  moves to a position radially outward of the end portion  86  of the first retaining leg  80 , and bends the end portion of the first retaining leg inward, toward the axis  118  and away from the edge surface  46  of the opening  40 . The first retaining leg  80  moves inward from the blocking position until its blocking surface  88  is clear of the edge surface  46  of the opening  40 , as shown in FIG.  11 . 
     Simultaneously, the inner side surface  170  of the second arm  164  of the second track  160  engages the end portion  96  of the second retaining leg  90 . The second arm  164  of the second track  160  moves to a position radially outward of the end portion  96  of the second retaining leg  90 . In this position, the second track  160  bends the end portion  96  of the second retaining leg  90  inward, toward the axis  118 , and away from the edge surface  48  of the opening  40 . The second retaining leg  90  moves inward from the blocking position until its blocking surface  98  is clear of the edge surface  48  of the opening  40 , as shown in FIG.  11 . 
     Thus, when the knob  14  is rotated relative to the base  12  so as to place the fastener  10  in the third or release condition shown in FIGS. 10-12, the retaining legs  80  and  90  do not block removal of the fastener  10  from the opening  40 . The first and second members  20  and  22  are no longer clamped together, and the fastener  10  can be removed from the opening  40 . 
     From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications in the invention. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.