Patent Publication Number: US-9420882-B2

Title: Sliding and pivoting mechanism of a rack of an item of furniture, item of furniture and domestic appliance

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. nationalization under 35 U.S.C. §371 of International Application No. PCT/EP2013/067646, filed Aug. 26, 2013, which claims priority to German Application No. 10 2012 107993.5, filed Aug. 29, 2012. The disclosures set forth in the foregoing applications are incorporated herein by reference in their entireties. 
     BACKGROUND AND SUMMARY OF THE DISCLOSURE 
     The present disclosure relates to a sliding and pivoting mechanism of a rack of an item of furniture or of a domestic appliance for pulling out and raising the rack from a body of the item of furniture. The disclosure further relates to an item of furniture as well as to a domestic appliance with such a sliding and pivoting mechanism. 
     These types of sliding and pivoting mechanisms are in particular often built into dishwashers, refrigerators, deep freezes (freezers) or cooking appliances in order to pull a bottom dish rack, container or cooked food carrier out of the washing space of the dishwasher, the interior of the fridge or deep freeze or the cooking space of the cooking appliance and at the same time to raise it upward into a position in which it is comfortable for the user to load and unload the dishwasher rack or cooked food carrier. 
     In the case of the sliding and pivoting mechanism known from DE 20 2009 004 771 U1, the raising or lowering of the rack is supported by means of a tension spring which cooperates with one of the pivot arms and consequently the loading or unloading is made easier insofar as the user is no longer forced to bend down for loading or unloading and consequently strain his back muscles and spine. Access to a lower-lying level is also made easier for wheelchair users, for example, by means of a sliding and pivoting mechanism. 
     U.S. Pat. No. 5,462,347 A makes known a sliding and pivoting mechanism where a storage compartment can be pulled out of a wall cabinet and then, by means of the sliding and pivoting mechanism, can be lowered in front of a storage compartment mounted below it in order to make access to the storage compartment easier. In order to prevent the lowered storage compartment from being pushed in, a bolt is provided on one of the pivot arms, said bolt protruding into the path of movement of a rear wall of the storage compartment in the lowered position and thus preventing an insertion movement in the lowered position. 
     Such a sliding and pivoting mechanism has proved its worth in practice. It is desirable to control the sequence of the pulling-out and raising movement or the lowering and pushing-in movement of the rack in a more precise manner in order to avoid, for example, it being raised when the rack is still partly pushed in. 
     A pivoting and sliding mechanism according to the disclosure may comprise at least two pivot arms which are rotatably secured on at least one of the side walls of a body with a first end parallel to the plane of the side walls, and arranged spaced part from one another in parallel, wherein a guide rail is secured on the respective second ends of the pivot arms so as to be pivotable in such a manner parallel to the plane of the side walls that the guide rail is pivotable from a bottom position inside the body into a raised, top position at least partially outside of the body, at least one running rail which is linearly displaceable in the guide rail and on which the rack is fastened, wherein the sliding and pivoting mechanism further comprises a locking mechanism, which is arranged on the guide rail and on one of the pivot arms, for preventing the running rail from simultaneously sliding and pivoting. 
     The sequence of the pulling out and raising movement or of the lowering and pushing in movement of the rack can be controlled in a precise manner by means of the locking mechanism such that, for example, the rack being simultaneously raised and extended is effectively prevented. A raising operation with the rack still partially inserted may be avoided as a result. 
     According to one embodiment of the disclosure, the locking mechanism is actuatable by an activator which is fixed on the running rail. 
     Because the activator is fixed on the running rail, it is possible to define a predetermined pull-out position of the rack at which a pivoting movement of the sliding and pivoting mechanism is first of all made possible such that a proper sequence of a pull-out movement of the rack from the body of the item of furniture is ensured. 
     According to one embodiment of the disclosure, the locking mechanism comprises a web, which is held so as to be pivotable and resilient on one of the pivot arms, with a bolt which protrudes in the direction of the guide rail and is guidable along a guide path, which is fastened to the guide rail, from a first locking position into at least one second locking position. 
     The locking positions, in this case, may be determined by locking grooves which define the guide path which is preferably realized as a curved portion. Precise coordination of the movement sequence of the pivot arms is made possible as a result of the bolt which is guided along the guide path. 
     According to a further embodiment of the sliding and pivoting mechanism according to the disclosure, the activator used to activate the locking mechanism comprises a first stop, by way of which the locking bolt can be moved in a direction of extension out of a position blocking a pivoting movement of the pivot arm in the first locking groove when the running rail is pulled out. As a result of the positioning of the activator at a predetermined position of the running rail, the trigger point of the pivoting movement of the pivot arms is determined in a simple and precise manner. 
     To guide the pivoting movement of the pivot arms in a precise manner, according to a further embodiment, the activator, which is fixed on the running rail, comprises a guide which guides the locking bolt along the guide path when the pivot arms are pivoted. As a result, the locking bolt is guided in a guide groove formed by the abovementioned components and can latch into the second locking groove once the rack has reached the upwardly pivoted position. 
     In order, once the loading or unloading has been carried out, to enable the rack to pivot back into the body, according to a further embodiment the activator, which is fixed on the running rail, comprises a web which rises in the manner of a ramp, by way of which the locking bolt can be moved in a direction of extension out of a position blocking a pivoting movement of the pivot arms in the second locking groove when the running rail is pulled out. 
     In a further embodiment of the disclosure, the activator comprises at least one fastening element for fixing the rack such that no further component is necessary on the running rail for fixing the rack and the activator serves for fixing the rack at the same time. 
     To guide the locking bolt precisely and to position it reliably in a locking groove, the locking bolt is preferably guided in a guide groove of the second guide arm which is aligned perpendicular to the longitudinal extension of the second guide arm. This ensures a simply linear movement of the locking bolt in relation to the second guide arm as the locking bolt itself, as already mentioned above, is fixed on a web which is held so as to be pivotable and resilient on the second pivot arm. 
     In order to make the raising and lowering of the rack additionally easier, a raising and/or lowering aid is secured on at least one of the side walls of the body and on one of the pivot arms for supporting the pivoting movement of the pivot arms. 
     To shield from contamination and/or to avoid, for example, a finger of a user from becoming caught, according to an embodiment, a cover, which covers the side face of the sliding and pivoting mechanism at least in part, can be arranged on the side of the sliding and pivoting mechanism remote from the rack. 
     To be able to detect a locking position which prevents the running rail from simultaneously pivoting and sliding or the reaching of said locking position, the locking position according to one embodiment of the disclosure is perceivable in an acoustic or visual manner. To this end, in one case a spring element can be latched in an acoustically perceivable manner in or on a projection which is provided on the pivot arm and in the second case a web with a visually recognizable control strip for indicating the locking position or the non-locking position of the sliding and pivoting mechanism is provided on the cover. 
     A runner system can include a guide rail, a running rail and as an option at least one center rail. 
     The sliding and pivoting mechanism can be secured in the body of an item of furniture or of a domestic appliance in a materially bonding, positive locking and/or non-positive locking manner. 
     The rack can be realized, for example, as a cooked food carrier, as a dish rack, as a drawer, as a container for refrigerated or frozen products or as a pull-out shelf. 
     The term item of furniture in the sense of this document also includes, for example, devices for laboratories, surgeries, workshops, ships, yachts, vehicles, caravans and mobile homes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the disclosure are explained in more detail below by way of the accompanying drawings, in which: 
         FIGS. 1 and 2  show a perspective view of an embodiment of a sliding and pivoting mechanism according to the disclosure in a completely lowered position as well as a representation of a detail of the region marked with II in  FIG. 1 ; 
         FIGS. 3 and 4  show perspective views of the sliding and pivoting mechanism from  FIG. 1  once the running rail has been displaced out of the guide rail prior to raising the sliding and pivoting mechanism as well as a representation of a detail of the region marked with IV in  FIG. 3 ; 
         FIGS. 5 and 6  show perspective representations of the sliding and pivoting mechanism in a position in which the pivoting movement of the pivot arms is released, wherein  FIG. 6  shows a representation of a detail of the cutout shown by way of the region marked VI in  FIG. 5 ; 
         FIGS. 7 and 8  show a perspective representation of the sliding and pivoting mechanism corresponding to  FIGS. 5 and 6  during a pivoting movement, wherein  FIG. 8  shows a representation of a detail of a cutout marked with VIII in  FIG. 7 ; 
         FIGS. 9 and 10  show a representation of the sliding and pivoting mechanism corresponding to  FIGS. 7 and 8  in a further progressed state of the pivoting movement, wherein  FIG. 10  shows a representation of a detail of the cutout marked with X in  FIG. 9 ; 
         FIGS. 11 and 12  show a representation of the sliding and pivoting mechanism corresponding to  FIGS. 9 and 10  directly prior to locking the sliding and pivoting mechanism in the upwardly pivoted position, wherein  FIG. 12  shows a representation of a detail of the cutout marked with XII in  FIG. 11 ; 
         FIGS. 13 and 14  show a representation of the sliding and pivoting mechanism corresponding to  FIGS. 11 and 12  in a further pivot-blocking position, wherein  FIG. 14  shows a representation of a detail of the cutout marked with XIV in  FIG. 13 ; 
         FIGS. 15 and 16  show a view of the sliding and pivoting mechanism corresponding to  FIGS. 13 and 14  during the release of the sliding and pivoting mechanism out of the top locking position, wherein  FIG. 16  shows a representation of a detail of the cutout marked with XVI in  FIG. 15 ; 
         FIGS. 17 and 18  show a view of the sliding and pivoting mechanism corresponding to  FIGS. 15 and 16  directly after the release position shown in  FIGS. 15 and 16 , as a result of which a renewed lowering of the sliding and pivoting mechanism is released, wherein  FIG. 18  shows a representation of a detail of the cutout marked with XVIII in  FIG. 17 ; 
         FIGS. 19 and 20  show a representation of the sliding and pivoting mechanism corresponding to  FIGS. 17 and 18  after the complete re-lowering of the sliding and pivoting mechanism directly prior to the returning of the locking bolt into the blocking position, wherein  FIG. 20  shows a representation of a detail of the cutout marked with XX in  FIG. 19 ; 
         FIGS. 21 and 22  show a view of the sliding and pivoting mechanism corresponding to  FIGS. 19 and 20  after reaching the position of the locking bolt in which an upward pivoting of the sliding and pivoting mechanism is blocked, wherein  FIG. 22  shows a representation of a detail of the cutout marked with XII in  FIG. 21 ; 
         FIG. 23  shows a perspective view of an embodiment of a sliding and pivoting mechanism according to the disclosure with a two-part fastening plate for fixing the sliding and pivoting mechanism on a side wall of the body; 
         FIG. 24  shows a perspective view of an embodiment of a sliding and pivoting mechanism according to the disclosure with a fastening plate for fixing the sliding and pivoting mechanism on a side wall of the body; 
         FIGS. 25 to 27  show perspective views of a body of a dishwasher with a top and bottom rack, wherein the bottom rack is provided with an embodiment of a sliding and pivoting mechanism according to the disclosure; 
         FIG. 28  shows a perspective view of a rack, which is fastened on the sliding and pivoting mechanism, in the extended state; 
         FIGS. 29 a  to  c    show perspective views of the sliding cabinet mechanism with a further embodiment of a fastening plate for fixing the sliding and pivoting mechanism on the side wall of a body; 
         FIG. 30  shows a perspective view of the sliding and pivoting mechanism show in  FIG. 28  without showing the rack in the extended state; 
         FIGS. 31 a  and 31 b    shows perspective views of the sliding and pivoting mechanism in the top locking position, showing the mounting of a spring element for preventing unwanted release of the sliding and pivoting mechanism out of said locking position; 
         FIGS. 32 a  to 32 c    show perspective views of a side cover of the sliding and pivoting mechanism as well as of the arrangement of said side cover on the sliding and pivoting mechanism; 
         FIGS. 33 and 34  show perspective representations of the sliding and pivoting mechanism in the top locking position in the non-locked state, wherein  FIG. 34  shows a representation of a detail of the cutout marked with XXXIV in  FIG. 33  and 
         FIGS. 35 and 36  show the perspective representations of the sliding and pivoting mechanism shown in  FIGS. 33 and 34  in the locked state, wherein  FIG. 36  shows a representation of a detail of the cutout marked with XXXVI in  FIG. 35 . 
     
    
    
     In the following description of the figures terms such as above, below, left, right, front, back etc. relate exclusively to the representation and position chosen as an example in the respective figures of the sliding and pivoting mechanism, the pivot arms, the guide rails, the running rail, the activator and the like. Said terms are not to be understood as limiting. This means said preferences can be modified as a result of different operating positions or the mirror-symmetrical design or the like. 
       FIGS. 1 to 22  show a first embodiment of a sliding and pivoting mechanism according to the disclosure, positions of the sliding and pivoting mechanism during the course of a raising operation and a subsequent lowering operation being shown as an example. 
     In this case, the sliding and pivoting mechanism according to the disclosure is used for pulling out and raising or lowering and pushing in a rack  15 , shown as an example in  FIGS. 25 to 28 , of a domestic appliance, such as the dishwasher  1  shown here, but it can also be built in general into items of furniture with a rack  15  which is to be able to be pulled out from a body  2  and raised into an elevated position in order to make it possible to load and unload the rack in a comfortable manner. 
     In each case in pairs,  FIGS. 1 to 22  show a perspective general view of an embodiment of the sliding and pivoting mechanism in a first of the respective pair of figures and in a second of the respective pair of figures a front view of a detail of a cutout marked by a circle in the first of the pair of figures. 
     As is shown, for example, in  FIG. 1 , the sliding and pivoting mechanism comprises at least two pivot arms  3 ,  4  which are rotatably fixed on at least one of the side walls  21 ,  22  (shown in  FIGS. 25 to 27 ) of a body  2  with a first end parallel to the plane of the side walls  21 ,  22  and are arranged spaced apart from one another in parallel. The second end of the pivot arms  3 ,  4 , in this case, is secured so as to be rotatable on a guide rail  5  of a runner system, in which the at least one running rail  6  can be moved in a linear manner and on which the rack  15  is secured by means of the activator  7  and the fixing device  8 . The pivot arms  3 ,  4  are fastened, in this case, on the side wall  21 ,  22  of the body  2 , preferably by means of a side wall holder  12  which can be mounted on a side wall  21 ,  22  and on which the pivot arms  3 ,  4  are secured so as to be pivotable by means of respective pivot joints  31 ,  41 . The pivot arms  3 ,  4 , in this case, are fastened on the guide rail  5  so as to be pivotable by means of further pivot joints  32 ,  42  (shown in  FIG. 28 ) such that the guide rail  5 , when the pivot arms  3 ,  4  pivot, remaining in the horizontal position can be pivoted out of a bottom position inside the body  2  into a raised top position at least partially outside the body  2 , as is shown in  FIGS. 26 and 27 . A synchronization element  16  for synchronizing the movement of the pivot arms  3  is provided between shoulders  34  of the pivot arms  3  which are arranged on both sides of the rack  15 . The synchronization element  16 , in this case, is realized in a preferred manner as a bar that is fastened to the shoulders  34  for example with rivets  35 , fastening plates  161  with bores for pushing through the rivets  35  being provided on the ends of the bar, as is shown in  FIGS. 28 and 30 . 
     To support the raising or lowering movement, a raising and/or lowering aid  11  for supporting the pivoting of the pivot arms  3 ,  4  is provided on at least one of the side walls  21 ,  22  or on the side wall holder  12 . The raising or lowering aid  11 , in this case, is realized in a preferred manner as a tension spring  11  which is fastened on respective bolts  33 ,  123  at the one end on the side wall holder  12  and at the other end on a first of the pivot arms  3 . 
     It is also conceivable for the raising and/or lowering aid  11  to be realized as a pneumatic spring. As a result, it is possible to provide higher forces with the installation space remaining the same. The pneumatic spring additionally comprises the advantage of a closed system, consequently, in contrast to tension springs in the form of spiral springs, does not have any hollow or intermediate spaces in which contamination or rinsing water residue is able to collect. 
     In order to prevent the pivot arms  3 ,  4  rotating beyond the top end position, a stop  121  is realized in a preferred manner on the side wall holder  12 , against which stop the upper end face of the first pivot arm  3  strikes when the top end position is reached. In an embodiment, the stop  121 , in this case, is provided on the stop face with an elastic material, for example, a rubber coating, in order to prevent the pivot arm  3  from striking in a hard and noisy manner against a stop  121  which is otherwise realized, for example, as a metal part. 
     In order to prevent the rack  15  and consequently also the sliding and pivoting mechanism from pivoting and sliding simultaneously, the sliding and pivoting mechanism comprises a locking mechanism which is arranged on the guide rail  5  and on one of the pivot arms  3 ,  4  and is actuatable by means of an activator  7  which is fixed on the running rail  6 . 
     The locking mechanism, in this case, preferably comprises a web  9 , which is held so as to be pivotable and resilient on one of the pivot arms  3 ,  4 , with a bolt  91  which protrudes in the direction of the guide rail  6  and is guidable along a guide path  103  which is fastened on the guide rail  5 . Said guide path  103  is realized in a preferred manner as part of a plate  10  which is fastened on the guide rail  5 , part of the edge of the plate  10  forming the guide path  103  which is defined by the respective locking grooves  101 ,  102  and the guide path  103  being realized in a preferred manner as a curve portion along which the bolt  91  is guided during the pivoting movement of the pivot arms  3 ,  4 . 
     The web  9 , in this case, is held on the second pivot arm  4  by means of a pivot bolt  92 , the bolt  91  being guided in a preferred manner in a guide groove  44  of the second pivot arm  4  such that the web  9  is able to move away from a side edge of the pivot arm  4  corresponding to the longitudinal extension of said guide groove  44  at its end spaced from the pivot bolt  92 . A spring element  94  between the web  9  and the second pivot arm  4 , in this case, is developed in such a manner that the bolt  91  is always pulled in the direction of the plate  10 . 
     In an alternative embodiment shown in  FIGS. 31 a   ) and  b ), the web  9  is connected to the pivot arm  4  by means of a spring element  95  which is positioned in such a manner that it acts upon the bolt  91  with a force, as a result of which the bolt  91  is prevented from being released unintentionally out of the locking groove  102 . The spring element  95  is realized in an embodiment as a plastics material element that interacts with a projection on the pivot arm  4 . 
     In the embodiment shown here, the spring element  95  is realized in multiple parts and consists of a first housing part  951  and a second housing part  952  which are connected together, in particular by means of riveting or clipping, on both sides of the web  9  through an elongated hole  96  which is punched in the web  9 . A spring arm  953  which is mounted by way of its free end in a hole  45  in the pivot arm  4 , is integrally molded on the second housing part  952 . 
     It is also conceivable to realize the locking of the bolt such that it has to be released actively by the user, for example by pressing a button or pulling a bar. 
     The activator  7 , which is fastened on the running rail, comprises a stop  74  on its end face which points in the direction of extension A. The stop  74  serves the purpose of moving the locking bolt  91  out of a position blocking a pivoting movement of the pivot arms  3 ,  4  in the first locking groove  101  when the running rail  6  is pulled out.  FIGS. 1 and 2  show here the position of the sliding and pivoting mechanism in which the rack still rests completely in the body  2 . As can be seen clearly in  FIG. 2 , the bolt  91  rests in the locking groove  101  of the plate  10  such that a pivoting movement of the pivot arms  3 ,  4  is blocked. The activator  9 , which is fastened on the running rail, serves in a preferred manner at the same time for fixing the rack  15  and for this reason comprises, for example, clamping grooves  71 ,  72 . 
       FIGS. 3 and 4  show the position of the sliding and pivoting mechanism where the running rail  6  is displaced in the direction of extension A in relation to the guide rail  5 . The activator  7 , in this case, is displaced forward in the direction of extension A by the movement of the running rail  6  until the stop  74  abuts directly against the bolt  91 . Further displacement of the running rail  6  in the direction of extension A then initially causes, as shown in  FIGS. 5 and 6 or 7 and 8 , the bolt  91  to be pushed out of the locking groove  101  into the region of the guide path  103 , as is shown in the view of the detail in  FIG. 8 , in which the pivoting movement of the pivot arms  3 ,  4  is then made possible. 
     To guide the bolt  91  along the guide path  103 , a guide  75  is provided on the rear side of the activator  7  facing the pivot arms  3 ,  4 , which guide, together with the guide path  103 , forms a guide channel in which the bolt  91  is guided during a raising operation of the sliding and pivoting mechanism, as is shown for example in  FIGS. 9 and 10 , until the pivot arms  3 ,  4  have reached their top end positions. In said position, shown in  FIGS. 11 and 12 , the bolt  91  abuts against a stop  104  of the plate  10  and at the same time blocks a further movement of the bolt  91 . In said position, the web  9  is pulled with the bolt  91  by the spring element  94  in the direction of the second pivot arm  4  such that the bolt  91  slides along the stop  104  into the second locking groove  102  and consequently completely blocks a pivoting movement of the pivot arms  3 ,  4 . 
     In said position, the rack  15 , which is fastened on the running rail  6 , is in its raised end position in which a user is able to load or unload the rack  15  without at the same time having to bend down. In this case, the locking mechanism ensures that the rack remains in said position and unwanted lowering, for example as a result of loading a rack  15  with a heavy object, is effectively prevented. 
     In order to move the sliding and pivoting mechanism back again into its starting position once said top end position has been achieved, the runner system is first of all pulled a little further in the direction of extension A. In this case, the bolt  91  is raised out of the locking groove  102  as a result of a ramp  76  which is realized on the activator  7 , as is shown in  FIGS. 16 and 18 , such that the bolt  91  is then once again able to move along the guide path  103  of the plate  10  into the bottom position in the direction of the first locking groove  101 , which is accompanied by a lowering of the guide rail  5  and of the running rail  6  as a result of the pivoting movement of the pivot arms  3 ,  4  until the lowered position, shown in  FIGS. 19 and 20 , is once again reached in which, as a result of the running rail  6  being moved back against the direction of extension A, the bolt  91  is once again pulled into the bottom locking groove  101  such that further pivoting of the pivot arms  3 ,  4  is once again blocked and the rack  15  or the running rail  6  is able to be moved in a linear manner completely back again into the body  2 . 
       FIGS. 23, 24 and 29  additionally show another embodiment of a side wall holder which is formed in said exemplary embodiment by a side wall holder  12  and an auxiliary plate  13 , the auxiliary plate  13  being fixed on the side wall  21 ,  22  of the body and the sliding and pivoting mechanism being able to be fixed by attaching the side wall holder  12  on the auxiliary plate  13 . In this case, the side wall holder  12  comprises recesses  124 ,  125  for receiving hooks  131  which are provided on the auxiliary plate  13  and are insertable into the recesses  124 ,  125  of the side wall holder  12  and are lockable as a result of displacement in elongated slots  126  which extend from the recesses  125 . In a preferred manner, once mounted in the recesses  124 ,  125  the hooks  131  are secured against loosening and contamination by retaining elements  122 . The retaining elements  122 , in this case, are produced in a preferred manner from plastics material and can be clipped onto the hooks  131  or into the recesses  124 ,  125 . Other production materials, such as, for example, metal, or other securing methods are also conceivable. 
     The auxiliary plate  13  can also be realized integrally with the wall of an item of furniture or of a domestic appliance. The hooks  131  can also be secured individually at the corresponding positions in an item of furniture or a domestic appliance. The sliding and pivoting mechanism can be secured in the body of an item of furniture or of a domestic appliance in a materially bonding, positive locking and/or non-positive locking manner. 
     In a further embodiment, shown in  FIGS. 32 to 36 , a cover  17 , which on the one hand serves for preventing contamination of the sliding and pivoting mechanism as well as also as (finger) protection and at least partially covers the side face of the sliding and pivoting mechanism, is mounted on the side of the sliding and pivoting mechanism remote from the rack  15 . 
     The cover  17 , in this case, is realized with multiple parts in the embodiment shown here and consists of a first cover part  171  and a second cover part  172 . Realizing the cover  17  in one part is also conceivable. 
     The cover  17  or the cover parts  171 ,  172  preferably consist of a flat plastics material profile with recesses  173 ,  175  and/or openings  174  for surrounding a pivot joint  32 ,  42  and the web  9 , which, in a preferred manner, is reinforced at least locally by means of ribs  176 . The fastening of the cover parts  171 ,  172  is preferably effected without any tools, for example as a result of snapping on with the help of projections  177  which are integrally formed on the cover parts  171 ,  172 . 
     In order to make the latching of the sliding and pivoting mechanism in the top locking position recognizable to the user, it is provided according to an embodiment to realize the locking process by means of audible feedback of the locking process by means of the spring element  95  which latches in or on a projection on the pivot arm  4  in an audible manner. 
     According to an alternative embodiment, the latching of the sliding and pivoting mechanism in the top locking position is visually recognizable to the user, as is shown in  FIGS. 33 to 36 . 
     As can be seen in the representation of the detail in  FIG. 34 , a web  178  with a, for example, color-marked control strip, which is positioned such that in the non-locked position of the mechanism it can be viewed by the user and in the top locking position of the bolt  91  is covered by a lug  97  which is integrally molded on the web  9 , is provided on the cover  17  for this purpose. 
       FIGS. 33 and 34  show the unlocked state where the bolt  91  is released out of the locking groove  102 . In said position, the spacing between the web  9  in the region of the bolt  91  and the pivot arm  4  is large enough for the web  178  with the control strip to be visible. 
       FIGS. 35 and 36  show the locked state where the web  9  abuts directly against the pivot arm  4  and is held by the spring element  95  in said position. The web  178  with the control strip is covered by the lug  97  in the locked position.