Patent Publication Number: US-8528173-B2

Title: Shockproof, quick-action closure for an end fitting

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to German Patent Application No. 10 2008 004 338.9, filed Jan. 15, 2008 and PCT patent application PCT/EP2009/000023, filed Jan. 7, 2009. 
     FIELD OF THE INVENTION 
     The invention relates to a quick-action closure for an end fitting of a safety belt, whereby the quick-action closure comprises an insertion tongue which can be inserted into a closure housing and which can be locked therein by means of a locking element disposed in a mobile manner between a locking position and a release position, and whereby the locking element can be transferred from its locking position into its release position by means of an actuating element which can be inserted into the closure housing. 
     BACKGROUND OF THE INVENTION 
     A quick-action closure with the aforementioned features is described in DE 102 45 818 A1. Such a quick-action closure is concerned with creating the possibility of bringing the locking element for the insertion tongue into the release position by means of an actuating tool, which can be applied to the quick-action closure, and thus releasing the quick-action closure in a straightforward and reliable manner. Especially if such a quick-action closure is used with an end-fitting tightener, there is the requirement for the quick-action closure to be designed shockproof in the direction of movement corresponding to its longitudinal direction. 
     With the known quick-action closure, the locking element comprises two symmetrically constructed tong elements, which are mobile at right angles to the insertion direction of the insertion tongue and, in the locking position, engage laterally behind a widened head of the insertion tongue. The tong elements are subject to the action of a spring which constantly pretensions them into the locking position. Due to their symmetrical arrangement, the tong elements in fact act in an acceleration-neutral manner, but with the known quick-action closure there is still the drawback that, both during the insertion of the insertion tongue and during the pushing-apart of the tong elements by means of the applied actuating element, the action of the spring must in both cases be overcome, but for safety reasons the latter must be designed suitably strong in order that a reliable fixing of the insertion tongue in the closure housing is guaranteed. 
     The problem underlying the invention is to make available a quick-action closure with the generic features, which on the one hand enables easy insertion and removal of the insertion tongue, but at the same time is designed shockproof. 
     The solution to this problem, including advantageous configurations and developments of the invention, emerges from the contents of the claims which follow this description. 
     SUMMARY OF THE INVENTION 
     In its basic idea, the invention makes provision such that a safety element is disposed in the closure housing mounted at its center of gravity rotatable between a safety position and a rest position, said safety element in its safety position fixing the locking element in its locking position and, in its rest position, releasing the locking element, whereby the safety element is held in its safety position by the action of a spring. For the fixing of the locking element in its locking position and for the simultaneous shockproofing of the quick-action closure, the safety element according to the invention is provided which is rotatable about an axis of rotation corresponding to its center of gravity. The safety element is not therefore subject to any turning moments when linear acceleration forces occur, so that the safety element remains, without its active movement, in its safety position, in which it is additionally secured by the spring action. 
     In order to exert the spring action, provision is made according to an example of embodiment of the invention such that the spring is designed as a torsion spring formed with two free ends, one end whereof extends into the path of movement of the insertion tongue and the other end whereof acts on the safety element, whereby provision can be made for the secure connection of the spring to the safety element such that the safety element comprises a channel for accommodating the assigned end of the torsion spring. 
     According to an example of embodiment of the invention, provision is made such that the spring is disposed in such a way that the spring tensioned by the insertion tongue, which is inserted and locked in the closure housing, holds the safety element in its safety position. 
     With regard to the release of the locking for the insertion tongue, provision is made according to an example of embodiment of the invention such that the safety element comprises, in addition to its retaining stop fixing the locking element in the safety position, an actuating stop for the actuating element introduced into the closure housing. In this regard, this is associated with the advantage that only the safety element has to be withdrawn from its safety position by the action of the actuating element, in order that the locking element, which is not subject to the spring action, is easily released. 
     For the formation of the actuating stop, provision can be made such that the rotatably disposed safety element is provided with a radial cutout disposed in such a way that the actuating stop can be acted upon in the safety position of the safety element by the actuating element, which can be inserted into the closure housing in the insertion direction of the insertion tongue. 
     In order that it is ensured, despite the provided cutout, that the center of gravity of the safety element coincides with its axis of rotation, provision is made such that the safety element is provided with a mass balance designed with respect to the radial cutout; such a mass balance can be created for example by another cutout correspondingly provided rotation-symmetrically. 
     According to an example of embodiment of the invention, provision can be made such that the closure housing is designed U-shaped with two housing plates laterally bounding the insertion path for the insertion tongue and a web connecting the housing plates, and that the insertion tongue, on its side facing away from the web, has a locking recess for the engagement of the locking element and, with its rear side lying opposite the locking recess, rests in the locking position against the web of the housing. 
     According to an example of embodiment of the invention, provision is made such that the actuating element is designed as a fork-shaped tool with two forks, one fork whereof is orientated towards the actuating stop of the safety element when the actuating element is inserted into the closure housing and the other fork whereof acts on the locking element in its direction of movement from the locking position into the release position. Provision can further be made such that the respective path of movement of the forks of the actuating element is disposed on different sides of the axis of rotation of the safety element and that the rotational directions of the movement of the safety element from its safety position into its rest position and of the locking element from its locking position into its release position are orientated in an opposing manner. 
     In detail, provision can further be made according to an example of embodiment of the invention such that the forks of the actuating element have a different length such that, when the actuating element is inserted into the closure housing, the one fork first acts on the actuating stop of the safety element and rotates the safety element into its rest position and then the other fork takes up the locking element and transfers it into its release position. 
     In order to incorporate a quick-action closure into a safety belt system, provision is made according to an example of embodiment of the invention such that the insertion tongue forms the end fitting connected to the belt band and that the closure housing is connected to a cable leading to the end-fitting tightener. Alternatively it can be provided that the closure housing is connected to a holder or to a belt strap. 
     According to embodiment of the invention it can be provided that the locking element is disposed with its swiveling mobility around an axis which is arranged perpendicular to the lateral housing plates of the closure housing. According to an embodiment of the invention herewith it can be associated that the locking element is disposed with its swiveling mobility in the longitudinal direction of the closure in a plane parallel to the lateral housing plates of the closure housing. 
     It can be provided that the center of gravity of a mass being formed from the safety element and the spring is arranged within the center of rotation of the safety element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An example of embodiment of the invention is reproduced in the drawing and is described below. In the figures: 
         FIG. 1  shows a quick-action closure in a schematic side view at the start of the insertion of the insertion tongue into the closure housing, 
         FIG. 2  shows the quick-action closure according to  FIG. 1  shortly before the locking position of the insertion tongue is reached, 
         FIG. 3  shows the quick-action closure according to  FIGS. 1 and 2  in the locking position of the insertion tongue, 
         FIG. 4  shows the quick-action closure according to  FIGS. 1 to 3 , during the opening process initiated by means of an actuating element inserted into the closure housing, 
         FIG. 5  shows the tool inserted according to  FIG. 4  and used as an actuating element, in a detail representation. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As first emerges from  FIG. 1 , quick-action closure  10  comprises a U-shaped closure housing  11 , lateral housing plates  12  whereof are connected via a web  13  and form between them the insertion path for an insertion tongue  16 . At its one (left-hand) end, closure housing  11  is connected via a fastening fitting  15  to a cable  14  preferably leading to an end-fitting tightener. Insertion tongue  16 , which can be inserted from the other (right-hand) side into closure housing  11 , has at its outer end an eyelet  17  for the connection of a safety belt band. 
     Lying opposite rear side  18  of insertion tongue  16  which slides over web  13  when insertion tongue  16  is inserted into closure housing  11 , there is disposed on insertion tongue  16  a locking recess  19 , into which a plate-shaped locking element  20  mounted in a swiveling manner in closure housing  11  can be swiveled, whereby locking element  20  is swiveled in the counter-clockwise direction out of the release position shown in  FIG. 1 , so that—as shown in FIG.  3 —the (right-hand) end of plate-shaped locking element  20  facing insertion tongue  16  is raised and at the same time the other (left-hand) end dips into locking recess  19  of insertion tongue  16  and locks the latter. 
     For the fixing of locking element  20  in its locking position and for the simultaneous shockproofing of quick-action closure  10  against acceleration forces occurring in the longitudinal direction of the closure, a safety element  21  is mounted rotatably in the closure housing  11 , whereby center of gravity  35  of a mass which is formed by the safety element  21  and of a spring  25  to be described later on at the same time forms the point of rotation for the rotation of safety element  21  between the rest position which can be seen from  FIG. 1  and  FIG. 2  and the safety position which can be seen in  FIG. 3 . But it can be sufficient if only the center of gravity  35  of the safety element  21  is incorporated into the definition for the center of rotation for the rotation of the safety element  21 . Safety element  21  has a retaining stop  22 , with which it engages over and locks plate-shaped locking element  20  in its locking position. By providing a cutout  24 , there is also formed on safety element  21  an actuating stop  23 , which in the safety position of safety element  21  ( FIG. 3 ) extends into a channel, which runs parallel to insertion tongue  16  and into which a tool-like actuating element  29  can be inserted to release safety element  21  ( FIG. 4 ). 
     Also disposed in the closure housing  11  is a spring  25  in the form of a torsion spring with two free ends  26  and  27 , one cranked end  26  of spring  25  extending into the path of movement of insertion tongue  16 , so that spring end  26  is acted on by insertion tongue  16 . Other end  27  of spring  25  is pushed into a channel  28  formed on safety element  21 , so that a direct coupling of spring end  27  with safety element  21  results. 
     As shown in  FIG. 1 , insertion tongue  16  is pushed into closure housing  11  in order to couple together a safety belt system described for example in generic DE 10245818 A1. Insertion tongue  16  with its front end comes to rest here against end  26  of spring  25  and thus tensions spring  25 . At the same time, the front, beveled edge of insertion tongue  16  raises plate-shaped locking element  20  at its inner edge. As soon as this inner edge has reached locking recess  19  formed in insertion tongue  16 , locking element  20  on the one hand swivels into locking recess  19 , whereby at the same time spring  25  tensioned by the insertion movement of insertion tongue  16  into closure housing  11  rotates, via spring end  27 , safety element  21  in the clockwise direction. A surface  36  is disposed on safety element  21 , such that, as a result of the rotation of safety element  21 , the swiveling motion of locking element  20  into its locking position is guided in locking recess  19 . At the end of the locking path, retaining stop  22  of safety element  21  and/or the surface  36  lies against locking element  20  and thus prevents a movement of locking element  20  into its release position. In this locking position, safety element  21  continues to be subject to the action of spring  25  tensioned by insertion tongue  16  ( FIG. 3 ). 
     Since, according to the invention, the axis of rotation coincides in the case of safety element  21  with its center of mass  35 , no turning moments occur in the presence of acceleration forces acting in the longitudinal direction on closure housing  11 , so that an automatic movement of safety element  21 , against the force of spring  25 , is avoided and quick-action closure  10  is thus held in the locked state. 
     If such a quick-action closure  10  is to be opened by means of an actuating element, actuating element  29  represented in  FIG. 5  is provided, which is formed fork-shaped with an upper fork  30  and a lower fork  31 ; upper fork  30  has a greater axial length extension than lower fork  31 . In addition, lower fork  31  is provided at its front end with a run-up bevel  32 . 
     If actuating element  29  is pushed into closure housing  11  from the insertion side of insertion tongue  16 , axially projecting upper fork  30  comes to rest first against actuating stop  23  of safety element  21 , said actuating stop standing up in the safety position of safety element  21 . With further pushing-in, safety element  21  is rotated counter-clockwise out of its safety position in the direction of its rest position, whereby, during this pushing-in of actuating element  29 , lower fork  31  with run-up bevel  32  formed thereon comes into contact with locking element  20  standing obliquely to the insertion direction and raises the locking element in the clockwise direction out of locking recess  19  of insertion tongue  16 . Following this, insertion tongue  16  together with actuating element  29  should be withdrawn from closure housing  11 , this process being supported by tensioned spring  25 , which is then for the most part relaxed and available for a renewed insertion process of insertion tongue  16 . 
     In a further embodiment of the invention, provision is made such that the actuating element can also be applied to closure housing  11  laterally, i.e. at right angles to the plane defined by housing plates  12  of closure housing  11 , whereby projections are provided on the actuating element in such a way that a rotation of the actuating element brings about both a rotation of safety element  21  out of its safety position ( FIG. 3 ) in the direction of the rest position ( 1 ) as well as a tilting of locking element  20  between its locking position ( FIG. 3 ) and its release position ( FIG. 1 ). 
     The features of the subject-matter of these documents disclosed in the above description, the claims, the abstract and the drawing may be essential individually as well as in any combinations with one another for the implementation of the invention in its various embodiments.