Abstract:
A hinge for metal cupboard doors or the like, comprising a first hinged piece such as a hinge plate with one or several counterbored holes for fixing screws and a second hinge piece articulated on the first hinge piece such as a hinge frame or hinge plate, which is also provided with several counterbored holes for fixing screws, wherein the holes of the at least one hinge part are configured as oblong holes. The hinge is provided with a fixing screw bushing which can be fitted into the oblong hole, and whose part fitting into the counterbored area of the oblong hole has a cross-section which differs from a circular form, i.e. a quadratic cross-section, preferably a longitudinally extended rectangular, rectangular with added semicircles of an oval cross-section, and whose longitudinal extension is (the same or) greater than the transversal extension of the counterbored area of the oblong hole and whose inner counter matches the shape of the fixing screw.

Description:
BACKGROUND OF THE INVENTION 
     a) Field of the Invention 
     The invention is directed to a hinge for sheet-metal cabinet doors, machine casings, housing covers, or the like, comprising a first hinge part, such as a hinge leaf, with one or more countersunk openings for fastening screws and with a second hinge part articulated at the first hinge part, such as a hinge support or another hinge leaf, provided with one or more openings for fastening screws, wherein the countersunk openings of the at least one hinge part are constructed as elongated holes. 
     b) Description of the Related Art 
     A hinge of the type mentioned above is already known from the German Utility Model 29 51 712.1 of the present Applicant. Compared with previous constructions, for example, those cited in this Utility Model as prior art, the screw-on hinge known from this Utility Model already overcomes certain disadvantages occurring particularly in sheet-metal cabinet doors; that is, sheet-metal cabinet doors tend to warp during production or when mounted, which can impede opening and closing of the door, especially when close fits are provided between the door frame and door leaf. In order to avoid this disadvantage, it is suggested in the Utility Model to construct the openings in the hinge leaves as elongated holes. A certain adjusting possibility will result depending on the orientation of these elongated holes. If the orientation is parallel to the hinge axis, the height of the door leaf can be adjusted with respect to the door frame, for example. On the other hand, if the orientation is vertical to the hinge axis, the vertical gap between the door leaf and door frame can be adjusted with respect to its width. 
     In the reference cited above, the hinge comprises two leaves, which offers the possibility of providing a leaf with elongated holes oriented parallel to the hinge axis and the other leaf with elongated holes oriented perpendicular thereto, so that a two-dimensional alignment possibility is provided. 
     The reference states that it is advantageous to countersink these openings and, instead of standard screw bolts and nuts for fastening the hinge leaves, to use screws which are screwed into rivet nuts or blind rivet nuts. Cap screws whose head dimensions are adapted to the dimensioning of the countersink on the outer side of the hinge leaf are provided as fastening screws. On the other side, the rivet nuts or blind rivet nuts form an outer rivet collar having an outer diameter to which a (necessary) countersink on the inner side of the hinge leaf is adapted. In this way, the projecting rivet collar can be received on the one hand and its interfering influence can accordingly be eliminated and, on the other hand, this rivet collar can be utilized for alignment and for additional support of the hinge plates. 
     However, it is disadvantageous that rivet nuts or blind rivet nuts of the type mentioned above which project over the sheet-metal surface and are fixedly connected with the sheet metal of the door leaf or door frame can only be used in certain cases. If the fastening means are to be completely removed for certain purposes or if the projections are bothersome, nuts which are riveted in in this way cannot be used. 
     A further disadvantage of the known arrangement consists in that the fastening screw can move in the elongated hole along the longitudinal extension thereof when the fastening screw is not properly tightened. This risk is particularly high when the sheet-metal cabinet is subjected to a shaking movement during transport or during operation. A further disadvantage consists in that the elongated hole also remains partly visible when the fastening screw is mounted and there remain openings acting as dirt collectors which can be troublesome, e.g., when a switching cabinet is used in the food industry. 
     A further disadvantage consists in that the known hinge must always be adjusted even when the cabinets are manufactured in a very precise manner. The reason for this is that the known hinge has no “zero setting” or “reference position” which could be used when an adjustment was really not required in terms of the basic design of the cabinet. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is the primary object of the invention to further develop a hinge of the type mentioned above in such a way that, without the aid of rivet nuts or blind rivet nuts which must be fixedly and non-removably introduced in the sheet-metal material, as many advantages of the latter as possible are achieved, especially increased strength relative to shear forces, improved security with respect to unwanted displacement, possible use of a zero position or reference position when required, and complete covering of the elongated hole opening when required. 
     This object is met according to the invention in that the hinge is provided with a fastening screw bushing which can be received so as to fit in the countersunk hole and which projects into the hinge leaf and possibly through this hinge leaf and whose portion which extends into the countersunk area of the elongated hole and/or over the support surface of the hinge leaf has a cross section having a shape other than circular, such as a square cross section, but preferably an elongated cross section such as a rectangular cross section, a rectangular cross section with added semicircular portions, or an oval cross section, whose longitudinal extension is greater than (or equal to) the transverse extension of the countersunk area of the elongated hole and whose inner contour is adapted to the shape of the fastening screw. 
     On the one hand, this step increases the shear resistance of the arrangement because the bushing forms an additional material surface which resists the shear force; further, the screw is guided more exactly through the bushing, which facilitates mounting, and furthermore the bushing results in a larger support surface on the countersunk surface of the hinge leaf and therefore results in greater force transmission capacity which benefits strength, so that hinge leaves of plastic can be used in certain cases without the material being pressed apart by internal pressure on the lateral faces of the hole; further, the securing of the bushing against rotation within the countersink or within the door leaf opening which can be achieved according to the invention facilitates protection against unwanted loosening of the screws and, finally, additional embodiment forms having further advantages can be carried out. 
     It is possible to cover a larger support surface of the elongated hole and therefore reduce area pressure, which benefits the stability of the arrangement, according to a further development of the invention, in that the countersunk area of the elongated hole has, in cross section, side walls which are parallel to the axis of the opening and base surfaces perpendicular to these side walls and the portion of the bushing extending into the countersunk area of the elongated hole has a disk-shaped body whose circumference forms two oppositely located parallel portions whose radial spacing is equal to or slightly less than the clearance between the longitudinal walls of the countersunk area. Further, this results in a particularly reliable protection against rotation. 
     Protection against unwanted displacement in the direction of the elongated hole can be increased in particular in that the base surface of the countersunk area of the opening of the hinge leaf and the disk surface of the bushing supported thereon are roughened, e.g., ribbed. It is particularly advantageous when this ribbing runs substantially at right angles to the longitudinal axis of the elongated hole or to the longitudinal axis of the elongated cross section of the disk of the bushing. 
     In particular, the bushing can form a flange whose outer contour is selected in such a way that it covers the countersunk opening in every possible position of the bushing with respect to the elongated hole. This results in the intended complete covering of the elongated hole opening and accordingly in a favorable visual effect and avoids hollow spaces which open outward and in which dirt can settle. The flange can even absorb pressing forces and accordingly reduce forces acting on the side walls of the elongated holes, which is advantageous in plastic hinge leaves. 
     A further construction of the invention according to which the bushing forms a projection or shoulder extending through the elongated hole opening is particularly advantageous. When this shoulder extends over the support surface of the hinge leaf only so far that it remains in the wall material of the sheet-metal cabinet door or the like, a standard nut can be used. According to a further development, a cap nut is provided, in which the free end of the shoulder can be received so as to be fixed with respect to rotation relative to it. In this case, the shoulder penetrates the wall thickness of the door leaf and can accordingly project into the cap nut in a countersink formed by the latter. This construction is particularly stable, prevents the fastening nut from rotating along when the fastening screw is actuated, and also enables improved sealing of the entire arrangement. This sealing is further improved in that the cap nut has, on its support surface, an annular groove for an O-ring seal. 
     According to another embodiment form of the invention, the outer surface of the flange of the bushing is provided with a mark, for example, an arrow, which indicates, for example, the center transverse axis of the elongated profile of the disk, and a further mark is arranged at the hinge leaf which indicates the center transverse axis of the elongated hole opening, so that a zero position or reference position is obtained for the arrangement which becomes useful when warping need not be taken into account because of the cabinet construction, so that mounting can be carried out first with the reference position. Should it turn out subsequently that this reference position does not result in a satisfactory alignment, an alignment can still be carried out subsequently. 
     The bushing is advantageously provided with a conical countersink for receiving the appropriate conical head of the fastening screw. In this way, it is possible, e.g., to use commercially-available cap screws, which reduces production costs for the arrangement. A further advantage of this conical countersink consists in that there is more substance or material available so that the other tasks of the bushing can be better carried out. 
     The fastening screws are advantageously provided with a polygon countersink for a screwing tool in order to facilitate assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described more fully with reference to embodiment examples shown in the drawings. 
     FIG. 1 shows a first embodiment form of a hinge constructed according to the invention in a sectional view vertical to the hinge axis; 
     FIG. 2 shows a top view of the hinge according to FIG. 1; 
     FIG. 3 shows a view from below of a fastening screw bushing constructed according to the invention; 
     FIG. 4 shows an axial sectional view of this bushing; 
     FIG. 5 shows a side view of this bushing; 
     FIG. 6 shows a top view of this bushing; 
     FIG. 7 shows a view similar to FIG. 1 of another embodiment form of the hinge in which a cap nut is used; 
     FIG. 8 shows a top view of the cap nut; 
     FIG. 9 shows an axial sectional view through the cap nut; 
     FIG. 10 shows a rear view of the cap nut; 
     FIG. 11 shows a sectional view similar to FIG. 1 of another embodiment form of a hinge constructed according to the invention; 
     FIG. 12 shows a top view of the hinge according to FIG. 11; 
     FIG. 13 shows a view from below of a fastening screw bushing fitting the embodiment form according to FIGS. 11 and 12; 
     FIG. 14 shows an axial sectional view of the fastening screw bushing according to FIG. 13; 
     FIG. 15 shows a side view of this bushing; 
     FIG. 16 shows a top view of this bushing; 
     FIG. 18 shows a top view of a cap nut which is constructed so as to fit the bushing according to FIGS. 13 to  16 ; 
     FIG. 19 shows an axial sectional view through this cap nut; 
     FIG. 20 shows a view of this cap nut from the bottom; 
     FIG. 21 shows a top view in partial section of another embodiment form of the invention; 
     FIG. 22 shows a section through the arrangement according to FIG. 21 vertical to the hinge axis; 
     FIG. 23 shows an accompanying mortise of the door for mounting the hinge arrangement shown in FIGS. 21 and 22; 
     FIG. 24 shows a sectional view transverse to the hinge axis through a hinge arrangement for illustrating the advantages according to the invention; and 
     FIG. 25 shows a top view of the arrangement according to FIG. 24; 
     FIG. 26 shows a sectional view similar to FIG. 11 of another embodiment form in which the bushing extends up to the door leaf material, but does not penetrate it; and 
     FIG. 27 shows a top view of the hinge according to FIG. 26 showing a door opening with a square cross section for receiving the shoulder of the bushing such that this shoulder is fixed with respect to rotation relative to it. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 24 and 25 will be discussed first. These Figures show a sectional view and a top view of a screw-on hinge  10  for sheet-metal cabinet doors, or the like, which comprises a first hinge part  12 , in this case, a hinge leaf, with at least one, in this case, with three, countersunk openings  14 ,  16 ,  18  for fastening screws  20 , and a second hinge part  30  which is articulated at the first hinge part  12 , in this case, also a hinge leaf  30  provided with a plurality of openings  32 ,  34 ,  36  for fastening screws, wherein the countersunk openings  14 ,  16 ,  18  of at least one hinge part are constructed as elongated holes. In the present case, the hinge leaf  12  is fastened to a door frame  58  and the hinge leaf  30  is fastened to a door leaf  60 . 
     The elongated holes  14 ,  16 ,  18  of the hinge leaf  12  are oriented substantially at right angles to the axis of the hinge,  44 , while the orientation of the elongated holes  32 ,  34 ,  36  of the other hinge leaf  30  extends parallel thereto as can be seen in FIG.  25 . The arrangement of the direction of the elongated holes at right angles to the axis  44  makes it possible to adjust in the direction of the double-arrow  101  and therefore enables an alignment of the door leaf  60  with respect to the door frame  58  for adjusting the door gap formed therebetween as can be seen in FIG.  24 . On the other hand, the orientation of the openings  32 ,  34 ,  36  perpendicular thereto in the other hinge leaf  30  makes it possible to align the door leaf  60  in the direction of the double-arrow  102  parallel to the hinge pin or axis  44  and accordingly allows the height of the door leaf to be adapted or adjusted with respect to the door frame or the like, that is, in a direction parallel to the hinge axis. 
     In the construction shown in FIG. 24, the screws which hold the hinge leaf  12  at the door frame  58  and the hinge leaf  30  at the door leaf  60  are screwed into threads formed by blind rivet nuts  62  which are introduced in the door frame  58  and door leaf  60 . Blind rivet nuts  62  of this kind have a collar  56  which projects over the support surface  58  for the hinge leaf  12 . This is disadvantageous in certain applications and further requires a corresponding countersink  54  in the support surface  52  of the hinge leaf  12  and  30 . 
     The constructions described with reference to FIGS. 1 to  23  and  26 ,  27  make do with simple openings in the sheet metal (with a rectangular profile in FIGS.  26  and  27 ) at which the hinge devices are to be fastened or use threaded devices (FIG. 1) which do not project beyond the support surface of the sheet-metal cabinet on which the hinge leaf is to be mounted. 
     Accordingly, FIG. 1 shows a hinge  110  for sheet-metal cabinet doors, or the like, comprising a first hinge part  112  with a plurality of countersunk openings, in this case, two,  114 ,  118  and a second hinge part  130  which is articulated at the first hinge part  112  and likewise has a plurality of openings, in this case, two,  132 ,  136  for receiving fastening screws  130 , wherein the openings are countersunk elongated holes and the orientation of the elongated holes  114 ,  118  of one hinge part  112  extends at right angles to the hinge axis  44  similar to the view in FIG. 25, while the elongated holes  132 ,  136  of the other hinge part  130  are oriented perpendicular thereto, that is, parallel to the hinge axis  44 . 
     In the construction according to FIGS. 24 and 25, the heads of the fastening screws  20 ,  32  are accommodated in countersinks  48 . The heads of these fastening screws can guide the hinge during displacement in the direction of the elongated hole in case these heads reach to the walls of the countersinks. 
     In the construction according to FIG. 1, see also the top view according to FIG. 2, a fastening screw bushing  140  which can be received so as to fit in the elongated hole is provided in the countersunk elongated hole  114 ,  118  or  132 ,  136 ; the fastening screw bushing  140  is shown from below in FIG. 3, in an axial view in FIG. 4, in a side view in FIG. 5, and in a top view in FIG.  6 . This bushing has a countersunk round bore hole  111  whose shape is adapted to the fastening screw  120  to be used, preferably in such a way that the end face of the screw head is flush with the outward facing end face of the bushing, see reference number  141 , so that the two form a smooth surface. If the screw head is constructed cylindrically, as is shown in FIG. 24, the countersunk opening  111  of the bushing  140  will also be constructed in this manner and a cylindrical countersink will be provided. However, in the preferred countersunk cap screw according to FIG. 1 with its conically extending head, the countersunk bore hole  114  is also provided with a corresponding conically shaped countersink. 
     When screwing the screw  120  into a thread  162  which is formed, e.g., by a sheet-metal wall  160 , it is advantageous to ensure that the bushing  140  is not carried along in the opening, e.g.,  118 , formed by the hinge leaf  112  or  130 . For this reason, the portion of the bushing extending into the countersunk area of the elongated hole (e.g.,  118 , area  143 ) is provided with a cross section not having a circular shape, such as a square cross section, preferably an elongated cross section such as a rectangular cross section (FIG.  13 ), a rectangular cross section with added semicircular portions (FIG.  3 ), or an oval cross section, whose longitudinal extension  143  is greater than the transverse extension  145  of the countersunk area  147  of the associated elongated hole, e.g., elongated hole  118 . In this way, it is ensured that the fastening screw bushing  140  is inserted with its longer extension in the longitudinal extension of the countersink of the associated opening and is also held in this direction. In the case of openings  114 ,  118 , this is the direction perpendicular to the hinge axis  144  and in the case of openings  132 ,  136  this is the direction parallel to the axis  44 . 
     It is most simple for the countersink  147  of the elongated hole, e.g.,  114 , according to FIG. 1, to have, in cross section, side walls  151  parallel to the opening axis  149  and base surfaces  153  at right angles thereto, and for the portion  142  of the bushing  140  extending into the countersunk area  147  of the elongated hole to form a disk-shaped body whose circumference  155  forms two oppositely located parallel portions  157 ,  159  whose distance  161  from one another is equal to or slightly less than the clearance  145  between the longitudinal walls of the countersink  147 . 
     The base surface  153  of the countersink  147  of the opening, e.g.,  118 , of the hinge leaf, e.g.,  112 , and the disk surface  163  of the bushing  140  supported thereon are advantageously roughened, e.g., ribbed. This ribbing is advisably formed essentially perpendicular to the longitudinal axis of the elongated cross section of the disk of the bushing  140  or to the base surface of the countersink of the elongated hole  118 . 
     This step reduces the risk of slippage in the direction of the extension of the elongated hole when the fastening screw is tightened. The distance between the individual ribs determines the increment and, therefore, the accuracy of adjustment, e.g., 1 . . . 1.5 mm. 
     As can be seen in FIG. 2 in combination with FIGS. 3 to  6 , the bushing  140  forms a flange  165  whose outer contour  167  is selected in such a way that it covers the countersunk opening  147  in every position of the bushing  140  with respect to the elongated hole (e.g.,  118 ). 
     The hollow spaces, see  147  in FIG. 1, formed by the elongated hole are therefore closed toward the outside and, therefore, dirt can no longer collect there. 
     The appearance is also improved in this way as a comparison of FIG.  25  and FIG. 2 makes clear. 
     As is shown in FIG. 6, the flange can have a mark, e.g., in the form of an arrowhead  169 . 
     This arrow  169  indicates, e.g., the center transverse axis  171  of the elongated profile of the disk  142  which can be referenced with a mark  173  carried by the associated hinge part, e.g.,  112 , in FIG.  2 . In this way, it is possible when inserting the bushing  140  into the bore hole  118  to bring the bushing  140  first into a determined reference position (zero position), preferably the center position with respect to the two alignment movements within the elongated hole, so that it is possible to preassemble the hinge in a determined position. If it turns out later that this “normal” position is not optimal because of manufacturing tolerances, the fastening screw  120  can be loosened and displaced together with the bushing  140  along the extension of the elongated hole until the desired adjustment is achieved, whereupon the screw is tightened again and the bushing is secured inside the opening  118  due to the pressing pressure exerted by the fastening screw, which is possibly strengthened by the roughening or ribbing of the base surface  153  and  163 . 
     Instead of providing, e.g., a bead in the sheet metal  160 , in which a thread can be cut, see reference number  162  in FIG. 1, a standard screw nut  480 , possibly with a washer, can also be provided, see FIG.  26 . In an alternative and especially favorable embodiment form, a cap nut  180  is provided instead of a standard nut as can be seen in FIG.  7 . The cap nut  180  is shown in a top view in FIG. 8, in a cross-sectional view in FIG. 9, and in a separate view from the bottom in FIG.  10 . The special advantage of this cap nut  180  consists above all in the possibility of ensuring a gastight closure because the rear end of the screw  120  is completely enclosed, wherein the cap nut  180  can also have, on its support surface  175 , an annular groove  177  in which an O-ring seal  179  can be inserted. 
     In views similar to FIGS. 1 and 2, FIGS. 11 and 12 show another embodiment form of the hinge according to the invention in which the bushing  240  forms a shoulder  181  extending through the elongated hole opening  218 ,  236  and also through the material of the door leaf  160  (e.g., through a round hole  161 ) and is used in combination with a cap nut  280  which has an offset or countersink  183  in which the free end  185  of the shoulder  181  can be received so as to fit therein and, in particular, so as to be fixed with respect to rotation relative thereto, as can be seen in FIG.  11 . It is most simple to provide the shoulder  181  with a rectangular shape in cross section as is shown in FIG. 13, where the countersink  183  has a corresponding rectangular cross section. These steps make it possible to hold the nut  280  by means of the bushing  240  so as to rigid against rotation, so that it is not carried along when screwing in the fastening screw  120  and it is no longer necessary to hold this cap nut  280 , e.g., with a tool, when tightening the screw  120 . 
     In order to receive this shoulder  181 , the opening  218  in FIG. 12 is constructed somewhat differently than the opening  118  in FIG.  2 . In particular, the opening  218  is, in this case, rectangular and somewhat larger, while the countersunk region  247  forms a rectangle with added semicircular portions similar to the embodiment form shown in FIG.  2 . The rest of the steps described above such as an O-ring seal for the cap nut, roughened or ribbed support surfaces, marks for the orientation of the bushing, etc., can also be used in this case. 
     While the preceding description of embodiment examples referred to hinges formed of two screw-on parts, in the embodiment form shown in FIG. 21 only one hinge part, namely, hinge part  312  in this case, is screwed to a cabinet frame  358 , specifically, by using the bushings  140 , fastening screws  120  and cap nuts  180  that have already been described. In order to protect against rotation, at least two such screws are advantageously provided, as is clearly shown in FIG.  21 . The other hinge part  330 , on the other hand, is fastened in a mortise or notch  331  in the door leaf  360  by means of a clamping pin  333  which, in the present case, also simultaneously forms the hinge pin. This type of fastening is known, per se, and is mentioned only to show that the arrangement according to the invention can be used in different types of hinges. 
     In the embodiment form shown in FIGS. 21 and 22, the orientation of the countersunk elongated hole openings is parallel to the hinge axis, so that the height adjustment of the door leaf  360  can be changed with respect to the door frame  350 . 
     In a construction with perpendicular orientation of the elongated holes relative to the hinge axis, it would be possible to adjust the lateral distance of the door leaf from the door frame. 
     In this case, also, further developments such as those already mentioned in connection with the preceding embodiment examples are also possible. 
     The most advantageous shape for the head of the fastening screw  120  is the truncated cone shape shown in the drawing because this shape provides more material for the cross section of the bushing according to the invention than would be possible in other head shapes. More material increases the strength of the bushing and provides more leeway for other configurations. 
     As can be seen, for example, from FIG. 21, the head of the fastening screw  120  advantageously has a hexagon countersink for receiving a corresponding tool. Alternatively, a cross-recessed countersink, as is generally known, could also be provided, for example. 
     The hinge according to the invention with its different embodiment forms dispenses with the special rivet nuts in the cabinet sheet metal such as those described in connection with FIGS. 23 and 24, for example; however, it also dispenses with elongated holes in the sheet metal, which are not only difficult to produce but also difficult to seal, and yet are required for standard hinges when adjustability is necessary. 
     On the other hand, square holes which are conventional in sheet-metal cabinet construction, for example, with dimensions of 4×4 mm or 8×8 mm, see, e.g., FIG. 27, opening  461 , are well-suited for the arrangement according to the invention. In this case, the circumferential contour  255 , see FIG. 13, of the portion  242  of the bushing extending into the countersunk area  247  can be round because the protection against rotation is now ensured by the square hole in the sheet-metal cabinet. Further, it is possible to use the bushings in four positions that are offset by 90°, wherein four corresponding marks can be provided as is indicated in FIG. 21 by arrows  369 . 
     When the fastening screw bushings  440  are, e.g., square in cross section, extend into the sheet metal  460 , are secured therein against relative rotation and do not exceed the material thickness b of the door leaf  460  with their end projecting out over the support surface  463  by distance a, a standard nut  480 , possibly with a washer (not shown), can be used instead of a special nut  280  with a countersink  183  which would have to receive the end  185  of the bushing extending through the sheet metal  160  as was described in FIG.  11 . 
     The invention can be commercially applied in switch cabinet construction. 
     While the foregoing description and drawings represent the present 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.