Abstract:
A securing device for a seatbelt, in particular a motor vehicle seatbelt, includes a receiving device for receiving a plug-in element and a locking device for retaining the plug-in element in the receiving device for the purpose of securing the seatbelt. The securing device, which can be manufactured in a particularly simple manner, enjoys reduced production costs. The locking device reduces manufacturing costs by being formed exclusively of a single-part closure spring that is secured in or on the receiving device.

Description:
BACKGROUND 
   The present invention relates to a securing device for a seatbelt. In particular, the present invention relates to a securing device for a seatbelt of a motor vehicle. 
   German Utility Model DE 201 16 939 U1 (incorporated by reference herein) discloses a securing device that is an end fitting lock with which one end of a seatbelt is permanently secured to a vehicle chassis. The securing device of DE 201 16 939 U1 has a receiving device into which a plug-in element is introduced and retained therein, for the purpose of securing the seatbelt. To retain the plug-in element in the receiving device, a locking device is provided with which the introduced plug-in element is permanently locked. The locking device contains a scissor-shaped device that is held under prestress with a separate spring. As a result of the large number of parts (and their complexity) needed to manufacture the aforementioned securing device, the production and installation costs thereof are undesirably high. 
   Accordingly, the present invention has been made in light of the aforementioned problem. Specifically, an object of the present invention is to provide a securing device that can be manufactured in a particularly simple manner, thereby lowering production costs. Another object of the present invention is to provide a securing device that can be readily installed in a vehicle, thereby lowering installation costs. 
   SUMMARY 
   An embodiment of the invention addresses a seatbelt securing device that is configured to engage a plug-in element. The securing device includes, among other possible things: (a) a receiving device for receiving the plug-in element; and (b) a locking device for retaining the plug-in element in the receiving device to secure the seatbelt. The locking device is formed exclusively by a single-part closure spring that is secured in or on the receiving device. 
   In another embodiment of the securing device, the receiving device may be of single-part design. 
   In another embodiment of the securing device, the securing device may be formed exclusively by two parts, namely the single-part receiving device and the single-part closure spring. 
   In another embodiment of the securing device, the closure spring may be formed by a spring plate that is bent apart when the plug-in element is inserted into the receiving device. 
   In another embodiment of the securing device, the receiving device may be formed by a single part that is punched and bent. 
   In another embodiment of the securing device, the securing device may form an end fitting lock for securing one end of the seatbelt on a vehicle chassis. 
   In another embodiment of the securing device, the plug-in element may be secured on the vehicle chassis at one end of the seatbelt and one end of the end fitting lock. Further, an end fitting tightener may be provided between the end fitting lock and the vehicle chassis. Additionally or alternatively, the securing device may be secured on the seatbelt and the plug-in element may be secured on the vehicle chassis. Further, an end fitting tightener may be provided between the plug-in element and the vehicle chassis. 
   In another embodiment of the securing device, the closure spring may be U-shaped in cross-section such that the closure spring has a bottom region and two side regions. Further, the bottom region of the closure spring may form a stop for the plug-in element. Further, each of the side regions may have a recess into which a latching element of the plug-in element latches for locking purposes. 
   In another embodiment of the securing device, the plug-in element may have a lug-shaped cam that, in the locked position of the plug-in element, may rest on the bottom region of the U-shaped closure spring. 
   In another embodiment of the securing device, the lug-shaped cam, in the locked position of the plug-in element, may press the bottom region of the U-shaped closure spring in such a manner that the two side regions of the closure spring are pressed against side flanks of the plug-in element. 
   In another embodiment of the securing device, at least one of the latching elements of the plug-in element may be formed by a side flank region that includes a serrated region and an adjacent latching recess. 
   In another embodiment of the securing device, each of the latching recesses may have two latching edges that are substantially parallel to each other and substantially perpendicular to the side flanks. 
   In another embodiment of the securing device, each of the latching recesses may have a latching bottom that may be substantially perpendicular to the two substantially parallel latching edges and may be substantially parallel to an insertion direction of the plug-in element. 
   In another embodiment of the securing device, the U-shaped closure spring may be clamped between at least one U-shaped, in cross-section, support element and a corresponding support element that extends in a direction that is substantially perpendicular to the insertion direction. 
   In another embodiment of the securing device, the cross-sectional plane in which the U-shaped support element is U-shaped may be substantially perpendicular to the bottom region of the U-shaped closure spring. 
   In another embodiment of the securing device, the latching recesses and/or the recesses of the closure spring may form a means of securing against rotation. 
   In another embodiment of the securing device, the latching recesses of the means of securing against rotation may be of different sizes and/or provided at different vertical heights on the plug-in element. 
   In another embodiment of the securing device, the recesses of the closure spring of the means of securing against rotation may be of different sizes and/or provided at different vertical heights on the closure spring. 
   In contrast to the securing device of DE 201 16 939 U1, which has a locking device formed by a total of three parts (i.e., the two components of the scissor-shaped device and the separate spring), the locking device according to the invention uses just a single element to attain the same functionality. In other words, the present invention enables the locking device to be formed exclusively by a single-part closure spring that is secured in or on the receiving device. As a result, a substantial advantage of the locking device according to the present invention is that it can be manufactured very simply and cost-effectively. 
   In some embodiments, the receiving device may also be of single-part design. This design is particularly advantageous because the production costs are further reduced. As a result, the securing device may have only two parts, namely the single-part receiving device and the single-part closure spring. Further, the single-part closure spring may be simply and, therefore, advantageously formed by a spring plate that is bent apart when the plug-in element is fitted. Further still, the receiving device may be formed by a single part that is punched and bent and that can be manufactured very cost-effectively. Moreover, as a result of the simple design of the securing device according to the present invention, the securing device can be readily installed in, e.g., a motor vehicle, thereby reducing installation costs 
   The securing device may be used as an end fitting lock for permanently securing one end of a seatbelt to the vehicle chassis of a vehicle. In this connection, the plug-in element may be secured at one end of the seatbelt and the end fitting lock can be secured indirectly or directly to the vehicle chassis. Moreover, an end fitting tightener may additionally be arranged between the end fitting lock and the vehicle chassis and may be used to tighten the seatbelt in the event of an accident. 
   In some embodiments, the function of the lug-shaped cam may be to bring about a particularly secure locking of the plug-in element by those side regions of the closure spring that cause the latching to be securely and permanently pressed against the side flanks of the plug-in element, after locking has taken place. An unintentional release of the plug-in element from the receiving device may, therefore, be reliably avoided. Further, the securing device may be designed in such a manner that a release of the locking of the plug-in element from the outside is possible only with the aid of a tool, i.e., an unintentional release of the seatbelt may further be reliably avoided. 
   The U-shaped closure spring may be clamped on or in the receiving device between at least one U-shaped support element and a support element that is bent essentially perpendicular with respect to the insertion direction of the plug-in element. This advantageously lowers the production costs during the installation of the closure spring in the receiving device, as no further securing steps are required after the closure spring has been “clamped in”. 
   It is possible to accommodate the securing device in a separate housing. As a result, the access to the closure spring (e.g., to release the closure spring) may then occur via at least one opening hole in the housing. 
   It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below. 
       FIG. 1  is a perspective view that shows an exemplary embodiment of a plug-in element that is configured to engage a corresponding securing device that includes a receiving device and a closure spring; 
       FIG. 2  is a perspective view of the plug-in element introduced into the receiving device; 
       FIG. 3  is a cut-away perspective view that shows a top side of the securing device before the plug-in element is introduced in the receiving device; 
       FIG. 4  is a cut-away perspective view that shows the securing of the closure spring of the securing device; and 
       FIG. 5  is another cut-away perspective view that shows the securing of the closure spring of the securing device. 
   

   DETAILED DESCRIPTION 
   Embodiments of the present invention will be described with reference to the drawings. Like numbers are used throughout the drawings to refer to the same or similar parts and in each of the embodiments of the invention hereafter described. 
     FIG. 1  shows a securing device in the form of an end fitting lock  10  that is used for permanently securing one end of a seatbelt (not illustrated in  FIG. 1  for reasons of clarity) to a vehicle chassis. The end fitting lock  10  has a receiving device  20  that is formed by a single-part that is punched and bent. A closure spring  30 , which is U-shaped in cross-section and formed by a spring plate, is clamped on the receiving device  20 . 
   To secure the closure spring  30  on the receiving device  20 , the receiving device  20  has support elements  40  that are U-shaped in cross-section. Each of the support elements  40  is associated with a corresponding angled support element  50 . A bottom region  60  of the U-shaped closure spring  30  is securely clamped between the two U-shaped support elements  40  and the two angled support elements  50 . 
   As can be seen in  FIG. 1 , the U-shaped closure spring  30  has two parallel side regions  70 . Each of the parallel side regions  70  includes a recess  80  (only one of which is shown in  FIG. 1 ); the recesses  80  are used to lock a plug-in element  100  that is inserted into the receiving device  20 . The plug-in element  100  is provided with two parallel side flanks  110 , each of which includes a latching recess  120  and a serrated side flank region  130 . A pair of one latching recess  120  and one serrated side flank region  130  defines a latching element  140 . The latching elements  140 , which are on the insertion end of the plug-in element  100 , interact with the two recesses  80  of the closure spring  30 . This interaction is later explained with respect to  FIGS. 2 to 5 . 
   It should be readily recognized that the two latching recesses  120  may differ in size and/or location on the side flanks  110 . As a result, the plug-in element  100  may be locked only in a predetermined, relative position in the receiving device  20 . A poka-yoke securing means (i.e., a means of securing against rotation) may, therefore, be realized, thereby preventing the seatbelt from undesirably rotating through 180°. For this purpose, the recesses  80  of the closure spring  30  may be dimensioned to correspond to the different recesses  120  of the side flanks  110 , e.g., one of the recesses  80  may be smaller than the other recess  80  and/or may be arranged at a different vertical height on the closure spring  30 . 
   As can be seen in  FIG. 1 , the plug-in element  100  is equipped with a lug-shaped cam  170 , which is arranged at the front in the insertion direction P. When the plug-in element  100  is inserted, the two side regions  70  of the U-shaped closure spring  30  are pressed apart by the serrated side flank regions  130  until the plug-in element  100  finally latches completely into the recesses  80 . 
   To secure the seatbelt to the vehicle chassis, the seatbelt is secured to a securing region  200  of the plug-in element  100 , which securing region  200  is oval in cross-section. The plug-in element  100  is, of course, engaged with the end fitting lock  10 , which, in turn, is fastened indirectly or directly to the vehicle chassis. 
     FIG. 2  is a perspective view of the plug-in element  100  introduced into the end fitting lock  10 . It can be seen that the lug-shaped cam  170  of the plug-in element  100  rests on the bottom region  60  of the U-shaped closure spring  30  and presses the bottom region  60  downward in the insertion direction P. As a result, the side regions  70  of the U-shaped closure spring  30  are respectively pressed inward in the direction of arrows I and I′. 
   It can furthermore be seen in  FIG. 2  that the latching elements  140 , which are formed by the latching recesses  120  and the saw tooth-shaped side flank regions  130 , are respectively latched into associated recesses  80  in the side regions  70  of the U-shaped closure spring  30 . For this purpose, latching edges  300  of the latching recesses  120 , which are adjacent the associated serrated side flank regions  130 , bear directly against edge regions of the recesses  80  of the U-shaped closure spring  30 . Each of the latching recesses  120  also includes a latching bottom  180  (shown in  FIG. 1 ) that is substantially perpendicular to the associated latching edge  300  and parallel to the insertion direction P of the plug-in element  100 . The plug-in element  100  is, therefore, fixedly latched in the closure spring  30  and, in turn, is fixedly received in the receiving device  20 . 
   In addition, the U-shaped closure spring  30  is also likewise firmly fixed on the receiving device  20  by means of the lug-shaped cam  170 . Specifically, the pressure of the lug-shaped cam  170  acting on the bottom region  60  of the closure spring  30  results in the bottom region  60  being firmly clamped between the U-shaped support elements  40  and the angled support elements  50  of the receiving device  20 . 
     FIG. 3  shows a top view of the end fitting lock  10  and the plug-in element  100 , before the plug-in element  100  is inserted in the receiving device  20 . As shown, a rectangular (in cross-section) receiving region  400  of the receiving device  20  is formed by two receiving-part elements  410  and  420 . One of the two receiving-part elements  410  is U-shaped in cross-section. The other of the two receiving-part elements  420  is formed by a transverse web that lies opposite and parallel to the bottom region of the U-shaped receiving-part element  410 . At the receiving region end, the two receiving-part elements  410  and  420  are separated from each other by two slots  430 . The two slots  430  are present because of the production process, i.e., as previously explained, the receiving device  20  is formed of single part that is punched and bent. 
     FIGS. 4 and 5  illustrate the securing of the closure spring  30  on the receiving device  20 . It can be seen that the bottom region  60  of the U-shaped closure spring  30  is securely clamped between the two angled support elements  50  and the two U-shaped support elements  40 . To secure the closure spring  30  on the receiving device  20 , the closure spring  30  merely has to be pushed between the two U-shaped support elements  40  and the two angled support elements  50 . 
   In the case of the exemplary embodiment according to  FIGS. 1 to 5 , the seatbelt is secured in the oval securing region  400  of the plug-in element  100  and the receiving device  20  is secured to the vehicle chassis. Of course, the securing arrangement could be reversed, i.e., so that the end fitting lock  10  is secured to the seatbelt and the plug-in element  100  is secured to the vehicle chassis. 
   The priority application, German Application No. 10 2004 041 109.3, which was filed on Aug. 24, 2004, is incorporated herein by reference in its entirety. 
   Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.