Patent Publication Number: US-8123183-B2

Title: Fixing device for a plastic mounting or housing that can be fixed in a rectangular opening in a thin wall

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a national phase application of International Application No. PCT/EP2006/002930, filed Mar. 31, 2006 which claims priority German Application No. 20 2005 010 117.6, filed Jun. 28, 2005, the complete disclosures of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     a) Field of the Invention 
     The invention is directed to a fitting or housing of plastic such as a swivel lever control, socket wrench control, sash closure with a fastening device for fixing the fitting or housing in at least one preferably rectangular opening in a thin wall such as a sheet metal cabinet door and with tongues which project from the fitting or housing so as to be integral therewith, the free ends of the tongues being supported on the rear rim area or the edge of the opening. 
     b) Description of the Related Art 
     A fitting or housing of the type mentioned above is already known from U.S. Pat. No. 5,435,159. 
     The prior art has the disadvantage that the plastic has only limited strength and is only capable of applying a limited springing force. If greater forces are required, recourse must be had to fastening devices in which the tongues are fashioned from metal spring parts. The drawback in using tongues made of metal is that manufacture and mounting are more complicated and that owing to the fact that a third part must be used there is a risk of losing this part. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is the object of the invention to improve the advantages of the two known constructions in such a way that mounting is simplified and sufficient springing force is ensured at the same time. 
     The above-stated object is met in that a supporting spring which is made of spring metal and which is bent to form a profile that is U-shaped in cross section encloses the free end of the tongue. This reinforces and lends additional support to the tongue which is made of plastic having only limited strength and also only limited springing force. 
     On the other hand, the arrangement is also very simple and the fitting or housing of plastic which is provided with the fastening device according to the invention can be fastened in a very simple manner by snapping in. 
     In a particularly advantageous embodiment form, a supporting leg proceeds from one, inner leg of the U-shaped profile and rests against the housing wall from which the tongue projects. Accordingly, particularly high forces can be absorbed by the tongue without the plastic becoming brittle, for example, due to frequent mounting and disassembly, and without a reduction in fastening strength. 
     According to another embodiment form of the invention, a bend is provided at the end of the other, outer leg, which bend faces toward the tongue and is received in a slot formed in the latter. This results in a particularly secure positive engagement between the metal spring part and the plastic tongue region. 
     According to another embodiment form, the supporting leg forms a second U-shaped profile at the point where it joins the leg of the first U-shaped profile, and the outer surface of this second U-shaped profile faces along the housing wall, the tongue surface directed to it, and the transitional area between these two surfaces in a supporting manner. This improves the supporting action. 
     For the same reason, it is advantageous when the width of the supporting spring is adapted to that of the tongue and is selected in such a way that this width can be received in the transverse extension of the rectangular opening without substantial play, and the spring being locked axially in the opening. 
     In contrast to the plastic tongue, the springing force of the supporting spring can be adapted to requirements, for example, according to another embodiment form, in that the supporting spring has a greater material thickness where the first U-shaped profile joins the supporting leg and accordingly has a greater springing force than the adjoining area. Naturally, the spring in its entirety can also be made from spring metal of different thickness or different composition for adapting to the desired requirements. 
     When the outwardly directed surface of the tongue has a recess for receiving the spring thickness in such a way that the abutting outer surfaces of the tongue and spring form a continuous, uninterrupted surface in another embodiment form of the invention, no edges formed by the tongue surface can cause an impediment during the mounting process. 
     The fitting can be a trough which can be mounted for a swivel lever closure control in one or two rectangular wall openings. 
     Alternatively, the fitting can be the rectangular housing of a sash closure. 
     According to another embodiment form, the fitting can be the rectangular escutcheon of a folding lever closure. 
     According to another embodiment form, the fitting can be the rectangular escutcheon of a socket closure. 
     Alternatively, the fitting can be the rectangular bearing part of a toggle control, a toggle handle or a latch handle. 
     According to another embodiment form, the fitting is a rod guide which can be mounted in a rectangular opening. 
     According to another embodiment form, the fitting is a hinge block which can be mounted in a rectangular opening. 
     However, the fitting can also be a lever closure which can be mounted in a rectangular opening. 
     Finally, it is possible that the fitting is a handle trough or a hand grip which can be mounted in a rectangular opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained more fully in the following with reference to embodiment examples shown in the drawings. 
         FIG. 1A  shows a swivel lever control arranged at the door leaf with a fastening device according to the invention shown at the right-hand end; 
         FIG. 1B  shows the truncated end of a swivel lever closure according to  FIG. 1A  mounted in the door leaf; 
         FIG. 1C  shows a perspective view of the truncated end of the swivel lever closure according to  FIG. 1A  without the swivel lever and without a shaft; 
         FIG. 2  shows the spring device used in the embodiment form according to  FIG. 1A ; 
         FIG. 3A  shows a housing of a sash closure mounted in a door leaf; 
         FIG. 3B  shows the right-hand end of the housing shown in  FIG. 3A , but not mounted in a door leaf; 
         FIG. 3C  shows a perspective view of the right-hand side of the housing according to  FIG. 3A ; 
         FIG. 3D  shows a back view of the housing according to  FIG. 3A ; 
         FIG. 4  is a perspective view of the spring for the embodiment form according to  FIG. 3A ; and 
         FIG. 3E  shows the sash closure fully assembled and mounted in a door leaf according to the embodiment form in  FIG. 3A . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1A  shows a side view of a fitting or housing  20  of plastic such as a swivel lever control  20 , socket wrench control, or sash closure  120  with a fastening device  10  for fastening the fitting or housing  20 ,  120  in at least one, in this case, two, preferably rectangular openings  12 ,  14  in a thin wall  16  such as a sheet metal cabinet door and with tongues  22 ,  122  which project from the fitting or housing  20 ,  120  such that they are integral with the latter, the free end  24 ,  124  of the tongues  22 ,  122  being supported on the rear rim area or the edge  26  of the opening  12 ,  112 ,  14 . 
     According to the invention, a supporting spring  28 ,  128  which is made of spring metal and is bent to form a profile that is U-shaped in cross section encloses the free end  24  (see  FIG. 1A ) or  128  (see  FIG. 3A ) of the tongue  22 ,  122  in order to reinforce the tongue  22  and to protect it against wear during the mounting process during which the sharp edge  26  slides along the outer surface of the tongue  22 . The springing force of the plastic tongue against swiveling in direction of the housing  20 ,  120  can be appreciably increased when a supporting leg  34 ,  134  proceeds from one, inner leg  30 ,  130  of the U-shaped profile  32 ,  132 , this supporting leg  34 ,  134  resting against the housing wall  36 ,  136  from which the tongue  22 ,  122  proceeds. 
     In the embodiment form according to  FIGS. 1A ,  1 B,  1 C and  2 , a bend  42  of the free end of the leg  38  proceeds from the other, outer leg  38 ,  138 , this bend  42  facing toward the tongue  22  and being received in a slot  40  formed by this tongue. The spring  28  is connected to the tongue  22  particularly closely and in a positive engagement by means of this feature. This prevents the spring from slipping off from the tongue during the mounting process. A similar action is achieved in another embodiment form when the supporting leg  34 ,  134  of the supporting spring  28 ,  128  extends up to a transverse wall  44 ,  144  formed by the fitting  20 ,  120 , advisably the contact surface of the trough base  18   118  of the fitting or housing  20 ,  120  at the thin wall or door leaf  16 . 
     According to the embodiment forms illustrated above, the supporting leg  34 ,  134  forms a second U-shaped profile  66 ,  166  at its connection point  64 ,  164  to the leg of the first U-shaped profile  32 ,  132 , the outer surfaces  68 ,  168  and  70 ,  170 , respectively, of this second L-shaped profile  66 ,  166  facing along the housing wall  36 ,  136 , the tongue surface  72 ,  172  directed to it, and the transitional area between these two surfaces in a supporting manner. This improves the supporting action. 
     For the same reason, it is advantageous when the width  74 ,  174  of the supporting spring  28 ,  128  is adapted to that of the tongue  22 ,  122  and is selected in such a way that this width can be received in the transverse extension of the rectangular opening  12 ,  112  without substantial play, and the spring is locked axially in the opening. 
     In contrast to the plastic tongue, the springing force of the supporting spring can be adapted to requirements, for example, in that, according to another embodiment form, not shown, the supporting spring has a greater material thickness at the connection point  64 ,  164  between the first U-shaped profile  32 ,  132  and the supporting leg  34 ,  134  and accordingly has a greater springing force than the adjoining area. Naturally, the spring in its entirety can also be made from spring metal of different thickness or different composition for adapting to the desired requirements. 
     The outwardly directed surface  46 ,  146  of the tongue  22 ,  122  has a recess  48 ,  148  for receiving the spring thickness in such a way that the abutting outer surfaces of the tongue  22 ,  122  on the one hand and spring  28 ,  128  on the other hand form a continuous, uninterrupted surface so that the edge of the opening of the thin wall can slide along the surface without interference. 
     The fitting shown in  FIGS. 1A ,  1 B (in section) and  1 C (in a perspective view) is a swivel lever closure whose base  18  is provided at one end with a hook  50  which engages behind the thin wall or the door leaf  16 . A fastening device  10  constructed according to the invention is located at the opposite end. Naturally, a fastening device according to the invention can be provided instead of the hook  50 . Other component parts of the swivel lever closure device  20  are not shown, e.g., a profile cylinder which is mounted at  52  and the swivel lever  54  which is held in its swiveled in position inside the trough of the base  18  when closed. The swivel lever  54  is articulated at a shaft (not shown, which extends through the bearing housing with the bearing bore hole  56 . 
       FIG. 3E  is a side view showing the rectangular base  118  of the sash closure  120 . The sash or bolt  58  engages behind a door frame  60  and accordingly holds the door leaf  16  closed. The sash and accompanying shaft are not shown in the depiction of the housing in  FIG. 3A  in a side view, a three-dimensional view and a rear view, so that the bearing  62  can be seen. However, the fitting can also be the rectangular housing of a folding lever closure, wherein the fitting has a rectangular escutcheon, not shown. 
     The sash closure shown in  FIG. 3F  can also be considered as a socket wrench closure. Alternatively, a toggle control or a toggle handle or a latch handle can be used to operate the sash closure according to  FIG. 3F . 
     Alternatively, the fitting can also be a rod guide, not shown, which can be mounted in a rectangular opening. 
     According to yet another alternative, the fitting is a hinge block, not shown, which can be mounted in a rectangular opening. 
     According to yet another alternative, the fitting can also be a lever closure, not shown, which can be mounted in a rectangular opening. 
     Finally, it is possible that the fitting is a handle trough which can be mounted in a rectangular opening. A corresponding construction is shown in  FIG. 1A . 
     COMMERCIAL APPLICABILITY 
     The invention is commercially applicable in switch cabinet construction. While the foregoing description and drawings represent the present invention, it will invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention. 
     REFERENCE NUMBERS 
     
         
           10  fastening device 
           12 ,  112  opening 
           14  opening 
           16  thin wall, sheet metal cabinet door 
           18 ,  118  base 
           20 ,  120  fitting or housing 
           22 ,  122  tongue 
           24  free end 
           26  rear rim area, edge 
           28 ,  128  supporting spring 
           30 ,  130  inner leg 
           32 ,  132  first U-shaped profile 
           34 ,  134  supporting leg 
           36 ,  136  housing wall 
           38 ,  138  outer leg 
           40  slot 
           42  bend 
           44 ,  144  transverse wall, contact surface of the trough at the thin wall 
           46 ,  146  outwardly directed surface 
           48 ,  148  recess 
           50  hook 
           52  mounting point 
           54  swivel lever 
           56  bearing bore hole 
           58  sash, bolt 
           60  door frame 
           62  bearing bore hole 
           64 ,  164  connection point 
           66 ,  166  second U-shaped profile 
           68 ,  168  outer surface 
           70 ,  170  tongue surface 
           174  width of the supporting spring