Patent Publication Number: US-2010122437-A1

Title: Buckle for connecting first and second straps

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Austrian Patent application No. A 1794/2008, filed Nov. 19, 2008, and European Patent Application No. 09011303.6, filed Sep. 3, 2009, both of which are incorporated herein by reference as if fully set forth. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a buckle for connecting first and second straps, wherein this buckle comprises a buckle body that has left and right side parts with respect to the longitudinal direction of the straps to be connected and first and second cross bars running transverse to the longitudinal direction of the straps to be connected between the left and right side parts and wherein this buckle comprises a movable middle bar extending transverse to the longitudinal direction of the straps to be connected between the left and right side parts, wherein this middle bar is supported so that it can move relative to the left and right side parts in the longitudinal direction of the straps to be connected, wherein the middle bar rests on resting bars of the side parts. 
     2. Description of Related State of the Art 
     For connecting two straps, wherein the length of at least one strap is adjustable, buckles with fixed cross bars are known. Such buckles are also designated as tri-glide buckles or also as ladder-lock buckles (especially if more than three cross bars are provided). 
     It is further already known to arrange a middle cross bar that is designated below as a middle bar so that it can move relative to a buckle body in the longitudinal direction of the straps to be connected. The holding force against the pulling out of the length-adjustable strap is therefore increased. In the case of such a known construction, the middle bar made from metal rests on, on both sides, resting bars of the buckle body similarly made from metal. Side guide bars that are bent toward the side of the buckle body on which the middle bar rests on the resting bars are adjacent to the resting bars, so that they point upward at an angle. In the guide bars, window cutouts are formed into which angled end sections of the middle bar project. The angles of the middle bar are here directed opposite the angles of the guide bars. Therefore, the middle bar is held in the window cutouts so that it can move in the longitudinal direction of the straps to be connected but is held in the guide bars secured from being pulled out from the window cutouts. In the case of this known buckle, in order to ensure that the middle bar does not fall out from the window cutouts of the guide bars, the tolerances for the construction of the buckle must be relatively small. The bent end sections of the middle bar here lead to additional production complexity. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to provide a buckle of the type noted above in which a reliable support of the middle bar is achieved and which can be produced economically. 
     This is realized according to the invention in that a bent support bar extends from the resting bars, wherein this support bar has a section lying in front of each end face of the middle bar and a section with a cutout in which the respective end of the middle bar projects, and this section faces toward the resting bar from which the support bar extends. 
     In the case of a buckle according to the invention, a bent support bar extends from the resting bars for the middle bar. This support bar has a section lying in front of the adjacent end side of the middle bar, wherein this section is used as a stop for the middle bar against a shift of the middle bar in its axial direction, and this support bar further has a section that points in the direction toward the resting bar from which the support bar extends and has a cutout into which the respective end of the middle bar projects. This cutout extends in the longitudinal direction of the straps to be connected and its ends are used as stops for the middle bar, in order to limit the ability of the middle bar to move in the longitudinal direction of the straps to be connected. 
     Therefore, with the ability for simple production, a reliable holding of the middle bar on the buckle body can be achieved. 
     Advantageously, the cutouts holding the ends of the middle bar extend from the edge of the support bar running in the direction of the longitudinal extent of the straps to be connected. This edge is directed toward the resting bar from which the support bar extends and rests on the resting bar or has a spacing from the resting bar that is less than the thickness of the middle bar measured perpendicular to the surface of the resting bar on which the middle bar lies, so that the middle bar cannot be guided through the gap between the edge of the support bar and the resting bar. 
     Advantageously, the buckle body of the buckle according to the invention can be formed by a bent plate provided with corresponding cutouts. 
     The middle bar is advantageously formed in the shape of a flat plate. 
     In order to prevent undesired pulling of the length-adjustable strap from the buckle body, in the case of preferred embodiments of the invention, it can be provided that the buckle has at least one elastic biasing element that biases the middle bar in a direction parallel to the longitudinal direction. Through the biasing applied by the elastic biasing element, the strap wrapped around the middle bar is pressed against one of the cross bars, also without having to be pulled on the strap. This can thus be used, first, for preventing the strap from accidentally being pulled from the buckle body in the unbiased state. Furthermore, through corresponding dimensioning of the elastic biasing element, the holding forces produced by clamping the strap between the middle bar and the cross bar are generally increased, that is, also in the state in which it is pulled on the strap. A coil spring, for example, can be used as the biasing element. The elastic biasing element is favorably arranged within one of the bent support bars. Especially preferred embodiments of the invention provide that, within each of the bent support bars, there is at least one elastic biasing element. 
     The buckle can have, as shown farther below, a single buckle body on which two straps are attached. Alternatively, however, a two-part or multi-part construction of the buckle is also conceivable. Thus it can be provided, e.g., that the buckle has an additional buckle body that can be connected detachably to the buckle body with the bent support bars by a connection device, advantageously without a tool. Here, without a tool is to be understood that the connection device can be activated by hand, that is, without the use of a tool, in order to disconnect from each other the buckle bodies connected to each other and/or to reconnect them to each other. In the case of such two-part or multi-part buckles, it is then preferably provided that one of the straps to be connected to each other is mounted directly on the buckle body and the other of the straps to be connected is mounted directly on the additional buckle body. The attachment of this strap of the additional buckle body on the buckle body is then performed by the connection of the buckle body to the additional buckle body by the connection device. In the case of these variants, preferred constructions provide that the connection device has a latch device for the detachable latching of the additional buckle body with the buckle body. The elastic biasing element noted above biases the middle bar preferably in a direction pointing away from the additional buckle body. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Additional advantages and details of the invention are explained below with reference to the accompanying drawings. 
       Shown in the figures are: 
         FIG. 1  is a perspective view of a first embodiment of a buckle according to the invention, 
         FIG. 2  is an enlarged detail A from  FIG. 1 , 
         FIG. 3  is a view of the front side of the buckle according to  FIG. 1 , wherein the straps connected by the buckle are indicated schematically by dashed lines, 
         FIG. 4  is a view of the reverse side of the buckle according to  FIG. 1 , 
         FIG. 5  is an end-side view of this first embodiment, 
         FIG. 6  is a section along the line B-B from  FIG. 3 , 
         FIG. 7  is an enlarged detail C from  FIG. 6 , 
         FIG. 8  is a section along the line D-D from  FIG. 5 , 
         FIG. 9  is a front view of a second embodiment according to the invention, wherein the buckle is formed in two parts, 
         FIG. 10  is the section E-E from  FIG. 9 , 
         FIG. 11  is a perspective diagram of the embodiment according to  FIG. 9 , 
         FIG. 12  is a back view of the buckle body of the embodiment from  FIG. 9 , and 
         FIG. 13  is a back view of the additional buckle body of the embodiment according to  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first embodiment for a buckle according to the invention is explained below with reference to  FIGS. 1 to 8 . 
     The buckle of the first embodiment is used for connecting the straps  6 ,  7  that are shown in  FIG. 3  only by dashed lines and that extend starting from the buckle in a longitudinal direction  5  (strap  6 ) or against this longitudinal direction  5  (strap  7 ). The buckle has a buckle body  1  made from one piece with a first and a second cross bar  2 ,  3 . A middle bar  4  that can move to a limited extent in the longitudinal direction  5  is held on the buckle body  1 —with respect to the longitudinal direction  5  in the region between the first and the second cross bar  2 ,  3 . 
     The first strap  6  is guided around the first cross bar  2 , wherein, for attaching on the first cross bar  2 , a loop is formed by stitching  8  that is indicated by a dotted line in  FIG. 3 . The second strap is fed from the opposite side underneath the second cross bar  3  and the middle bar  4 , guided around the middle bar  4  and through the intermediate space  9  between the middle bar  4  and the second cross bar  3  and further fed back underneath the second cross bar  3 . The length of the second strap  7  is determined according to the overlap of the end  10  of the second strap  7  with the section of the strap  7  extending toward the buckle. 
     The first cross bar  2 , second cross bar  3 , and middle bar  4  extend transverse to the longitudinal direction  5  of the straps  6 ,  7 . 
     The first and second cross bars  2 ,  3  extend between right and left side parts  11 ,  12  of the buckle body  1  with respect to the longitudinal direction  5 . The middle bar  4  crosses over the free space between the side parts  11 ,  12  and lies with its two end sections on surfaces of resting bars  13   a ,  13   b  of the right and left side parts  11 ,  12  directed toward the front side of the buckle. 
     The resting bars  13   a ,  13   b  have a smooth construction and their surfaces on which the middle bar  4  lies, lie in a common plane. 
     The resting bars  13   a ,  13   b  are considered not only the sections of the buckle body  1  on which the middle bar  4  actually lies in its different possible displacement positions, but also its imaginary, straight-line projections in and opposite the longitudinal direction  5  up to the respective edge of the buckle body  1 . For illustration, the imaginary lines by which the resting bars  13   a ,  13   b  are delimited by the cross bars  2 ,  3  are shown with dashed lines in  FIG. 4 . 
     Support bars  16   a ,  16   b  extend from the edges  14 ,  15  of the flat resting bars  13   a ,  13   b  extending away from each other in the longitudinal direction  5  of the straps  6 ,  7  to be connected, wherein these support bars have a bent profile viewed in cross section (cf.  FIG. 6 , the section line B-B of this cross section runs transverse to the longitudinal direction  5 ). In a first section, the support bars  16   a ,  16   b  extend away from the plane of the surfaces of the resting bars  13   a ,  13   b  on which the middle bar  4  lies, wherein they extend in the region next to the end faces  17   a ,  17   b  of the middle bar  4 . Through the further bent profile, they extend in connection to a peak point  18 , in turn, in the direction toward the respective resting bar  13   a ,  13   b  from whose edge  14 ,  15  they project. These sections extending in the direction toward the respective resting bar  13   a ,  13   b  have cutouts  19   a ,  19   b  starting from their ends extending in the longitudinal direction  5  in which the two ends of the middle bar  4  project. The edges  20 ,  21  limiting the respective cutout  19   a ,  19   b  in the longitudinal direction  5  form stops for the middle bar  4 , in order to limit the range of movement of the middle bar  4  in and against the longitudinal direction  5 . The edge  22  of the cutout  19   a ,  19   b  extending parallel to the longitudinal direction  5  forms a guide for the middle bar  4  that limits the lift of the middle bar  4  from the respective resting bar  13   a ,  13   b . Here, only play sufficient for the movement of the middle bar  4  must be provided. Advantageously, this play measured perpendicular to the resting bar  13   a ,  13   b  is less than 2 mm, especially preferred less than 1 mm. 
     In the illustrated embodiment, the support bars  16   a ,  16   b  have a continuous, arc-shaped profile viewed in cross section. It would also be conceivable and possible, for example, that the support bars  16   a ,  16   b  are connected to the respective resting bar  13   a ,  13   b  by a more or less sharp kink. The section lying in front of the respective end face of the middle bar  4  could then have a flat construction and this section could be connected by a more or less sharp bend to the section having the cutout  19   a ,  19   b . As a whole, in turn, bent support bars  16   a ,  16   b  are formed whose free ends each point toward the resting bar  13   a ,  13   b  from which the support bars extend. 
     In this embodiment, the first cross bar  2  has a middle, bent region  23 , in order to form a grip element on which the buckle body  1  can be gripped and tilted, in order to pull the second strap  7  further from the buckle and to increase the length of the second strap  7 . 
     Advantageously, the buckle body  1  is made from metal. For the middle bar  4 , a construction from metal is also preferred. 
     The buckle body  1  can advantageously be formed from a plate on which the corresponding separating and shaping operations are performed. For forming the support bars  16   a ,  16   b , the plate is shaped with the already formed cutouts  19   a ,  19   b  by bending. 
     The thickness of the plate is here advantageously greater than 1 mm, especially preferred greater than 1.5 mm. 
     The thickness of the middle bar  4  is advantageously greater than 1 mm, especially preferred greater than 1.5 mm. 
     For example, the buckle body  1  and the middle bar  4  could have a thickness of 2 mm. 
     In principle, however, it would also be conceivable and possible to form the buckle body  1  from several parts connected rigidly to each other. 
     In other words, the buckle body  1  could also be described such that it has a main section lying in a plane with a window cutout that is crossed over by the displaceable middle bar  4 , wherein the bent support bars  16   a ,  16   b  extend from this main section on both sides. Furthermore, a bent region  23  for forming a grip part can be formed from this flat main section. 
     In principle, however, it would also be conceivable and possible to form the buckle body  1  with more than two fixed cross bars  2 ,  3  and/or to provide more than one middle bar  4  that is held on the buckle body  1  so that it can move in the described way. 
     In the scope of this publication, when straps are mentioned, belts and other flexible strip-shaped parts should also be included, especially also load-bearing, holding, and securing belts. 
     In the second embodiment of the invention according to  FIGS. 9 to 13 , essential parts are discussed analogous to the first embodiment, so that, in this respect, the above description of the first embodiment could be referenced. Below we will essentially discuss the differences between the first and the second embodiment. 
     A first difference lies in that, in the case of the second embodiment, the buckle has a buckle body  1  formed according to the invention and, in addition, an additional buckle body  24 . These two buckle bodies  1  and  24  can be connected detachably to each other by a connection device explained as an example farther below in detail. The first strap  6  is here attached, in contrast to the first embodiment, not on the buckle body  1 , but instead on the additional buckle body  24 . For this purpose, the latter has a third cross bar  31 , in order to be able to wrap the first strap  6  through the opening  32 . The first strap  6  can be fixed on the additional buckle body  24 , e.g., by stitching  8  analogous to the first embodiment. In the second embodiment, the strap  7  to be connected to the first strap  6  by the buckle is attached to the buckle body  1 , also like in the first embodiment. Analogous to the first embodiment, the second strap  7  is fed from the opposite side underneath the second cross bar  3  and the middle bar  4 , guided around the middle bar  4  and through the intermediate space  9  between the middle bar  4  and the second cross bar  3 , and furthermore fed back underneath the second cross bar. The length of the second strap  7  is determined according to the overlap of the end  10  of the second strap  7 . 
     In order to prevent undesired loosening or displacement of the second strap  7  in the non-tensioned state and/or to generally increase the holding forces that are holding the second strap  7  on the buckle body  1 , there can be at least one elastic biasing element  25  that biases the middle bar  4  in a direction parallel to the longitudinal direction  5 , as shown in the second embodiment. In the illustrated embodiment, it involves two such elastic biasing elements  25 . These are each arranged within the bent support bars  16   a  and  16   b . As the elastic biasing element  25 , all of the suitably elastic bodies known in the state of the art can be used. In the illustrated embodiment, each of the elastic biasing elements  25  involves a coil spring. The one end of the elastic biasing element is fixed in the respective bent support bar  16   a  or  16   b . On the opposite end of the elastic biasing element  25  lies the middle bar  4 , so that the middle bar  4  is here biased or spring-loaded in a direction  33  parallel to the longitudinal direction  5 . In the illustrated embodiment, the biasing is guided in the direction toward the second cross bar  3 , so that the strap  7  is clamped by the biasing of the biasing element  25  between the middle bar  4  and the second cross bar  3 .  FIG. 10  shows the section E-E from  FIG. 9  in which the position of the elastic biasing element is to be seen especially well in the support bar  16   a . The support bars  16   a ,  16   b , as well as the resting bars  13   a  and  13   b  and the cutouts  19   a  and  19   b , can be constructed as shown in the first embodiment with reference to  FIGS. 1 to 8 . This also applies especially for all of the details explained with reference to  FIGS. 4 to 8 . Deviating from the first embodiment, notches  26  are provided in the second embodiment in the support bars  16   a  and  16   b . However, these differences do not change the general construction and function of the right and left side parts  11  and  12  or the support bars  16   a  and  16   b . The notches  26  can also be eliminated accordingly, so that the side parts  11  and  12  could be constructed up to the additional biasing elements in their interaction with the middle bar  4  and the cross bars  1  and  2  like in the first embodiment. Accordingly, in the first embodiment, a biasing of the middle bar  4  in a direction parallel to the longitudinal direction  5  could also be performed, if the elastic biasing elements  25  of the second embodiment are integrated there. 
     As already explained, the buckle of the second embodiment according to the invention has a two-part construction. It has an additional buckle body  24  that can be connected detachably to the buckle body  1  by a connection device, advantageously without a tool. Such two-part buckles, and also buckles with more than two parts, are basically known in the state of the art in a plurality of constructions. The embodiment shown here shows only one of many possible variants. The same applies for the connection device for connecting the buckle body  1  and the additional buckle body  24 . In the illustrated embodiment, the connection device involves a latch device for the detachable latching of the additional buckle body  24  with the buckle body  1 . In the illustrated embodiment, the connection device or latch device comprises a female plug-in part  29  in which a male plug-in part  28  can be fixed detachably. For this purpose, the male plug-in part  28  has shoulders  30 , as to be seen especially in  FIG. 13 , which are in active connection in the inserted state according to  FIGS. 9 and 11  with counterparts of the activation lever  27  not shown in detail here, so that the two buckle bodies  1  and  24  are latched to each other in the connected position according to  FIGS. 9 and 11 . By activating the activation lever  27 , especially by hand, the additional buckle body  24  can then be pulled out from the buckle body  1 , so that the two buckle bodies, as shown in  FIGS. 12 and 13 , are separated from each other. Such buckle connections are known, as already mentioned, in a plurality of embodiments, so that here no additional explanations appear necessary. In principle, the invention can be combined together with all of the possible, known connection devices or embodiments of buckles with two or more parts. The variant shown here is only one example. In particular, it is to be noted that it does not absolutely have to be provided that the male plug-in part  28  is arranged on the additional buckle body  24  and the female plug-in part  29  is arranged on the buckle body  1 . A reverse arrangement is also definitely possible. In summary, it is also noted that in the second embodiment, both the buckle body  1  and also the additional buckle body  24  are constructed as components shaped from sheet metal or plates. In this way, the buckles according to the invention can be produced simply and economically. In particular, metal sheets can also be processed that are subsequently not to be hardened, as is the case, e.g., in water-resistant steels. Through the cold forming occurring during the bending of the sheets, a corresponding hardening process is achieved just during the bending. In conclusion, however, it should be noted that the invention naturally can be implemented not only in the form of buckle bodies made from bent plates. 
     LEGEND FOR THE REFERENCE SYMBOLS 
     
         
         
           
               1  Buckle body 
               2  First cross bar 
               3  Second cross bar 
               4  Middle bar 
               5  Longitudinal direction 
               6  First strap 
               7  Second strap 
               8  Stitching 
               9  Intermediate space 
               10  End 
               11  Right side part 
               12  Left side part 
               13   a ,  13   b  Resting bar 
               14  Edge 
               15  Edge 
               16   a ,  16   b  Support bar 
               17   a ,  17   b  End face 
               18  Peak point 
               19   a ,  19   b  Cutout 
               20  Edge 
               21  Edge 
               22  Edge 
               23  Region 
               24  Additional buckle body 
               25  Elastic biasing element 
               26  Notch 
               27  Activation lever 
               28  Male plug-in part 
               29  Female plug-in part 
               30  Shoulder 
               31  Third cross bar 
               32  Opening 
               33  Direction