Abstract:
A pull-out guide for drawers including a first rail and at least one second rail, and at least one carriage is arranged between the two rails. The carriage includes a bearing group containing load-transmitting elements, preferably rollers, rolling bodies and/or balls. The load-transmitting elements guide the bearing group in the vertical direction and in the horizontal direction. At least one additional load-transmitting element is arranged on a bracket, at a distance from the bearing group. When the second rail is pulled out, the additional load-transmitting element can at least partially move out over the end of the first rail, such that it no longer lies on the first rail.

Description:
This application is a continuation of International Application No. PCT/AT2007/000413, filed Aug. 30, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a pull-out guide assembly for a drawer comprising a first rail and at least one second rail. Arranged between those two rails is at least one running carriage having a bearing group with load-transmitting elements, preferably rollers, rolling bodies and/or balls. The load-transmitting elements guide the bearing group both in a vertical and also in a horizontal direction. 
     The invention further concerns a running carriage of such a pull-out guide assembly and an article of furniture with a pull-out guide assembly of the type to be described. 
     Pull-out guide assemblies for drawers of that kind can be both in the form of a single extension with a support rail to be mounted on the body of the article of furniture and a pull-out rail to be mounted on opposite sides of the drawer. The guide assemblies can also be in the form of a full extension guide assembly in which a middle rail is disposed between the pull-out rail rails and the support rails. The pull-out guide assemblies permit smooth running of the drawer or a compartment shelf with a high level of load-bearing capacity. In the closed condition of the drawer, particularly when a high level of loading is involved, the foremost load-transmitting elements of the running carriage displaceable between the rails are considerably loaded. If plastic rollers are employed as load-transmitting elements, those rollers can suffer deformation with time and as a result detrimentally affect the running characteristics of the pull-out guide assembly. 
     AT 365 433 discloses a full extension guide for drawers, wherein a carriage is arranged between the support rail associated with the body of the article of furniture and the middle rail. In the displacement travel of the rails, a rolling body associated with the carriage is movable beyond the end of the support rail. 
     U.S. Pat. No. 3,937,531 discloses a telescopic extension means for drawers, wherein a roller sliding bearing is arranged between the rails. In the closed position of the rails, all rollers bear against the support rail, while in the opening movement some rollers can be brought out of engagement from the support rail. 
     It is therefore an object of the present invention to propose a pull-out guide assembly of the general kind set forth in the opening part of this specification, having an improved durability and functionality. 
     SUMMARY OF THE INVENTION 
     The object of the invention is achieved in that there is provided at least one additional load-transmitting element arranged at a cantilever arm at a spacing relative to the bearing group. The additional load-transmitting element upon extension of the second rail can be moved at least region-wise beyond the end of the first rail so that it no longer bears against the first rail. 
     Those additional (closed-support) load-transmitting elements which in the movement of the rail system can be moved beyond the front end of the first rail (and which are desirably arranged as the foremost load-transmitting elements of the carriage in the extension direction of the rails) preferably serve only for supporting the drawer in the closed position. In the closed condition of the drawer, the additional (closed-support) load-transmitting element is most heavily loaded and takes up—at least partially—the load from the other remaining load-transmitting elements (which are supposed to serve as actual rolling bodies during the displacement movement of the rails). Besides improved load distribution, that provides that those additional load-transmitting elements which can overrun the front end of the first rail are subjected to flattening or deformation. However, the deformation is irrelevant, as these additional elements no longer operate as actual rolling members of the pull-out guide assembly during displacement of the drawer. In this connection, the at least one load-transmitting element rests on the first rail in the closed position of the rails and is out of engagement from the first rail in an open position of the second rail. 
     In accordance with a preferred embodiment of the invention, the cantilever arm is arranged in the axial direction of the carriage and in the extension direction of the rails. 
     In accordance with this aspect of the present invention, a standard carriage is provided with a cantilever arm pointing in the axial direction of the carriage. By means of such a construction, the spacing between the foremost axis and the rearmost axis of the rolling bodies of the carriage is also increased, which results in an improved load distribution for the drawer. In accordance with a further embodiment of the invention, it can also be provided that the cantilever arm can be coupled by a releasable fastening device with respect to the running carriage (for example with a coupling part) so that optionally cantilever arms of different lengths can be coupled to a carriage cage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further details of the invention will now be described with reference to the specific description hereinafter, in which: 
         FIG. 1  shows a perspective view of an article of furniture in cabinet form, with drawers which are mounted displaceably on pull-out guide assemblies according to the invention, 
         FIG. 2  shows a perspective view of a pull-out guide assembly in an open position, 
         FIG. 3  shows a perspective view of a running carriage in accordance with the invention, 
         FIG. 4   a - 4   c  show various detail views of a pull-out guide assembly in the closed position, and 
         FIG. 5   a - 5   c  show various detail views of a pull-out guide assembly in the open position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows an article of furniture  1  in the form of a cabinet having a furniture body  2 , wherein drawers  3   a  and  3   b  are guided displaceably therein by way of pull-out guide assemblies  4  according to the invention. The pull-out guide assemblies  4  are preferably fixed on both opposite side walls  5  of the furniture body  2  and can be in the form of a single extension guide assembly having a first rail  6  and a second rail  7 , or also in the form of a differential extension guide assembly having three rails, wherein the illustrated rail  7  takes over the function of the middle rail which is displaceably guided between the stationary first rail  6  and a pull-out rail  7  associated with the drawer. 
       FIG. 2  shows a pull-out guide assembly  4  for drawers  3   a ,  3   b  according to the invention, wherein the first rail  6  represents the support rail which is fixed with respect to the body of furniture and the second rail  7  is associated with the drawer  3   a  or  3   b . The second rail  7  is mounted displaceably relative to the first rail  6 . The first rail  6  has a running limb  6   a  against which a carriage, which is still to be described, can be caused to bear. In the figure shown, the illustrated pull-out guide assembly  4  is in an open position. 
       FIG. 3  shows an embodiment of a carriage  8  in accordance with an aspect of the invention, and the carriage  8  is guided displaceably between the first rail  6  ( FIG. 2 ) and the second rail  7  and is provided for transmission of the load of the drawer  3   a ,  3   b . The running carriage  8  comprises a carriage cage  9  with at least two mutually spaced bearing groups  9   a  and  9   b  which are connected together by a limb  9   c . The length of the limb  9   c  can vary according to the respective length of the rails  6  and  7  (that is to say, long rails  6  and  7  require longer carriages  8  or limbs  9   c , while shorter carriages  8  or limbs  9   c  are provided for short rails  6  and  7 ). The first and second bearing groups  9   a  and  9   b  are constantly in contact with the first rail  6  both in the closed position of the second rail  7  and also in the open position thereof. For that purpose, the bearing groups  9   a  and  9   b  have a first group of load-transmitting elements  10  with horizontal axes of rotation (for guiding the bearing group in a vertical direction) and also a second group of load-transmitting elements  10   a  whose axes of rotation at least in part differ from the horizontal and are preferably vertical (for guiding the bearing group in a lateral direction). The inclination of the axes of rotation of the load-transmitting elements  10   a  depends on the configuration or angular position of the running limb  6   a , shown in  FIG. 2 , of the first rail  6 . The running carriage  8  further comprises a control cam  11  which is known in accordance with the state of the art and which is provided to correct so-called carriage running errors which are a result of slippage of the running carriage  8  with respect to the rails of an at least three-part rail system. The function and configuration of the control cam  11  is not referred to in greater detail in the context of the present invention. Essential is the fact that the running carriage  3  comprises a cantilever arm portion  15  at its front face (i.e., forward of the bearing groups  9   a  and  9   b  with respect to the opening direction) which extends in an axial direction of the carriage  3  and in an opening direction of the rails  6 ,  7 . The cantilever arm  15  comprises a third group of preferably three additional load-transmitting elements  12  with horizontal axes of rotation. Those additional closed-support load-transmitting elements  12  of the cantilever arm  15  rest on the rail associated with the body of furniture in a closed position of the rails  6  and are subjected—in the closed position—to a higher load than the other remaining (first and second group) load-transmitting elements  10  of the actual carriage cage  9 . As such, premature flattening of the remaining (first and second group) load-transmitting elements  10  of both bearing groups  9   a ,  9   b  can be avoided. The additional closed-support load-transmitting elements  12  of the cantilever arm  15 , however, can overrun the front end of the first rail when the second rail is being pulled out so that the additional closed-support load-transmitting elements  12  of the cantilever arm  15  no longer rest on the first rail  6  in an open position of the rails  6 ,  7 . 
       FIG. 4   a - 4   c  show various views of the foremost region of the pull-out guide assembly  4  in the closed position.  FIG. 4   a  shows a top plan view of the closed pull-out guide assembly  4  with the first rail  6  to be fixed to the body of furniture  2  ( FIG. 1 ) and with the second rail  7  to be mounted to the drawer  3   a ,  3   b  ( FIG. 1 ). 
       FIG. 4   b  shows a vertical section of the pull-out guide assembly  4  along the plane I-I in  FIG. 4   a . To be seen is the carriage  8  which is displaceable between the rails  6  and  7  (disposed within the rectangular section), with its spaced bearing groups  9   a  and  9   b  and its cantilever arm  15 , at the distal end of which the additional closed-support load-transmitting elements  12  are rotatably arranged. In the illustrated closed position of the rails  6 ,  7 , the additional closed-support load-transmitting elements  12  of the cantilever arm  15  are supported against the horizontal portion of the running limb  6   a  of the first rail  6  associated with the body of furniture. The running limb  6   a  is constantly in contact with the load-transmitting elements  10  of the two bearing groups  9   a  and  9   b  on its top side and its underside. 
       FIG. 4   c  shows the rectangular detail illustrated in  FIG. 4   b  on an enlarged scale. The horizontal load-transmitting elements  10  of the first and second bearing groups  9   a  and  9   b  embrace the horizontal running limb  6   a  of the first rail  6  associated with the body of furniture. In the illustrated closed condition of the rails  6 ,  7 , the additional closed-support load-transmitting elements  12  of the cantilever arm  15  are supported against the top side of the horizontal running limb  6   a  and serve as additional support rollers. 
       FIG. 5   a - 5   c  show similar views to  FIG. 4   a - 4   c , with the difference that the second rail  7  is in an open position.  FIG. 5   a  shows a top plan view of the foremost region of the pull-out guide assembly  4 , with the second rail  7  being in an open position with respect to the stationary rail  6 . 
       FIG. 5   b  shows a vertical section along plane G-G in  FIG. 5   a , that is to say a sectional side view of the pull-out guide assembly  4 . 
       FIG. 5   c  shows the rectangular detail illustrated in  FIG. 5   b  on an enlarged scale (that is to say, an enlarged sectional side view of the pull-out guide assembly  4 ). As shown, the additional load-transmitting elements  12  of the cantilever arm  15  are no longer in contact with the first rail  6  associated with the body of furniture or the running limb  6   a  thereof, but have been extended beyond the end of the running limb  6   a  in the extension movement. The load-transmitting elements  10  of the two bearing groups  9   a  and  9   b  still contact the first rail  6 , at both sides of the running limb  6   a . The first rail  6  or the running limb  6   a  thereof has a diagrammatically illustrated inclined surface  13  in the front region—in the extension direction of the second rail  7 . That inclined surface  13  serves to lift the additional closed-support load-transmitting elements  12  of the cantilever arm on to the top side of the running limb  6   a  with an easy movement when the second rail  7  is pushed in again. In the illustrated embodiment, the inclined surface  13  is in the form of an angled portion of the running limb  6   a , but it is also possible to provide for an inclination of the running limb  6   a  as well as a separately arranged or formed run-on inclined surface for the additional load-transmitting elements  12 . 
     The present invention is not limited to the illustrated embodiment by way of example, but embraces or extends to all variants and technical equivalents which can fall within the scope of the accompanying claims. The positional references adopted in the description such as for example top, bottom, lateral and so forth are related to the usual position of installation of the extension guide  4  or the immediately described and illustrated Figure and upon a change in position are to be appropriately converted to the new position.