Patent Publication Number: US-6904645-B1

Title: Furniture hinge

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a furniture hinge for pivotally mounting a door leaf to a cupboard body, whose door-side front is narrowed by a frame that projects inwardly at a right angle to the side walls and is formed by strip-like frame elements. In a closed position, the frame overlaps at least partially with the inside of the door leaf. The furniture hinge further includes a hinge arm made of sheet metal and having on the side of the cupboard body a mounting plate which can be releaseably secured in superposition with a fastening plate disposed on the free end face facing away from the side wall of the frame element of the frame. At least one slot-like elongated through opening extending in the longitudinal direction of the front face of the frame element is provided in the mounting plate and in the fastening plate, through which the shank of a fastening screw may be screwed into the frame element. When the fastening screw is unscrewed, the fastening plate is held so as to be moveable in the longitudinal direction of the front face of the frame element, and the mounting plate is held so as to be moveable perpendicular thereto in the transverse direction of the front face of the fastening plate. 
     Hinges intended for cupboards with an inwardly projecting frame are typically mounted on the body side with a mounting plate that can be screwed onto the free front face facing away from the side wall of the inwardly projecting frame element. The width of the mounting plate can be approximately identical to the width of the front face of the frame element and form a part of a fastening plate, on which the actual hinge support arm that forms the body-side plate of the hinge can be adjustably attached. Alternatively, the mounting plate can also be an integral part of the hinge arm. To allow height adjustment of the door leaf hinged to the cupboard body after installation, the openings provided in the mounting plate for the fastening screw are typically formed as slots, so that—when the fastening screws are unscrewed—the height of the door leaf can be adjusted within the length range of the slots. The mounting plate is then fixed at the new set height of the door leaf by tightening the fastening screw. The position of the door leaf relative to the front side of the frame element of the cupboard body in the horizontal direction, i.e., the gap spacing between the inside of the door leaf and the front side of the frame element, can then typically no longer be changed, because such adjustment is intentionally prevented by folded-back tabs provided on the front end of the edge of the mounting plate that is connected to the supporting arm, wherein the tabs contact the front side or backside of the respective frame element. 
     In an improved furniture hinge as compared to older hinges of the aforedescribed type (DE 196 50 062 A1), the gap spacing can be further adjusted by securing the mounting plate that supports the hinge support arm on a separate height-adjustable fastening plate, which is mounted on the frame element in a conventional manner, with a slot for displacement in the transverse direction. The exclusive adjustability in the longitudinal direction of the end face of the frame element is again achieved by guiding the fastening plate on the front and rear side of the frame element and by a slot penetrated by the shank of the fastening screw and by having the support arm displaceable relative to the fastening plate by guides provided in the mounting plate in the displacement direction of the fastening plate. An opening for the shank of the fastening screw is also provided in the mounting plate, which is sized, on one hand, so as to allow the height adjustment and, on the other hand, has a large enough width in the transverse direction so as to enable the desired change in the gap spacing between the inside of the door leaf and the front side of the frame. To lock the adjusted position of the hinge, the head of a tightened fastening screw urges the fastening and mounting plate into contact with one another and into contact with the end face of the frame element. If the setting needs to be changed, then the fastening screw has to be unscrewed, which again allows adjustment in the two coordinate directions. For example, when only the gap spacing of a mounted hinge needs to be adjusted, then it may not be possible to maintain the—actually correct—height setting due to the weight of the door leaf. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide a furniture hinge of the aforedescribed type, which allows the required adjustments in height and a change of the gap spacing perpendicular thereto, whereby the hinge can be adjusted in one coordinate direction without the risk of an unintentional adjustment in the second coordinate direction. As an improvement of such a hinge, it should also be possible to adjust the clearance of the door leaf on the front side of the frame element, i.e., to adjust a third coordinate direction perpendicular to the two aforementioned coordinate directions. 
     Based on a furniture hinge of the aforedescribed type, the object is solved by the invention in that the fastening screw can be screwed into a fixing tenon, which is fixed in a bore hole disposed in the frame element and from which there protrudes at least one guide projection, which engages in the elongated through opening of the fastening plate and is supported by the side edges of the through opening, that a lug-like projection of an adjusting element provided with a cam is rotatably supported in a bearing bore disposed in the front end region of the fixing tenon, that the peripheral surface of the cam is supported on the longitudinal sides of the through opening of the fastening plate, with the cam having a diameter that is substantially identical to the width of the through opening of the mounting plate and being eccentrically offset relative to the lug-like projection, that the adjusting element includes an actuating section located above the cam and laterally overlapping with the mounting plate near the through opening, and that the head of the fastening screw can be screwed in so as to be in clamping engagement with the top side of the actuating section. 
     With the hinge of the invention, the shank of the fastening screw is no longer screwed directly into the frame element, but into a fixing tenon inserted into a bore of the frame element, which in turn has one or more guide projections that engage with the slot-like through openings of the fastening plate. In this way, the fastening plate is displaceable only into height direction. An additional cam which is rotatably supported in a bearing bore of the fixing tenon by a lug-like projection, is provided for adjusting the gap spacing. The cam engages with the edges of an elongated through opening disposed in the mounting plate that is significantly wider than the through opening in the fastening plate and—depending on its rotation position—fixes the position of the mounting plate relative to the fastening plate to adjust the gap spacing. Separate guides disposed on the mounting plate prevent an adjustment of the height of the mounting plate relative to the fastening plate. 
     Like a conventional furniture hinge, the fastening plate can have on at least one of its longitudinal edges a tab-like shoulder that is bent at a right angle, which in the defined mounting position on the end face of a frame element contacts the corresponding front and/or rear flat side of the frame element. In this way, the fastening plate cannot rotate on the front face of the frame element, which also prevents rotation of the fixing tenon fixed in the bore of the frame element. 
     Advantageously, the mounting plate is guided relative to the fastening plate in the desired adjustment direction by providing the mounting plate with tab-like shoulders that extend from its two edges oriented perpendicular to the longitudinal direction of the end face of the frame element and are bent in a direction towards the frame element, wherein the tab-like shoulders contact the corresponding edges of the fastening plate. 
     The actuating section of the adjusting element includes a lever-like extension through which the adjustment forces required for adjusting the gap spacing are introduced into the cam. The extension can include suitable means for engaging a tool, for example a screwdriver and the like. 
     To guarantee that the adjusting mechanism continues to function over extended periods of time and after multiple adjustments, the fixing tenon can be divided at least in its end region inside the bore by a transversely extending slit into two tenon halves which can be spread apart by screwing in the shank of the fastening screw. 
     Advantageously, the guide projection or guide projections can be formed so that the fixing tenon is guided in the through opening for displacement in the longitudinal direction, but formfittingly secured against rotation about its longitudinal center axis. 
     The guide projection or guide projections can be in a defined engagement position with the elongated through opening, with the slit extending between the two tenon halves of the fixing tenon located in a plane extending perpendicular to the longitudinal extent of the through opening and the flat sides of the fastening plate. When the fastening screws are tightened, the tenon halves are spread apart in the longitudinal direction of the frame element, thereby eliminating spreading forces that could attempt to split the frame element apart between the front and rear side. 
     The shank of the fastening screw can be screwed into the fixing tenon through a through bore disposed in the adjusting element, wherein the longitudinal center axis of the through bore coincides with the longitudinal center axis of the lug-like projection. The diameter of the through bore in the adjusting element is at least slightly greater than the maximum diameter of the shank of the fastening screw, which allows the adjusting element to rotate without introducing rotational forces into the fastening screw. 
     The width of the elongated through opening provided in the mounting plate is greater than the width of the elongated through opening provided in the fastening plate, so that the difference in width can be selected depending on the desired adjustments in the gap spacing. 
     A measurement of the depth of the bearing bore in the fixing tenon as measured in the direction of the longitudinal center axis is slightly greater than a measurement of the section of the lug-like projection, also measured along the longitudinal center axis, that engages in the bearing bore and extends from the flat underside of the cam which is supported on the top side of the fastening plate. With this arrangement, the projection is able to rotate by preventing the end face form pressing against the bottom of the bearing bore even when the fastening screw is tightened. 
     According to another embodiment of the invention, the lug-like projection can be prevented from unintentionally coming out of the bearing bore when the fastening screw is not inserted, by providing the section of the lug-like projection that engages in the bearing bore with a circumferential annular projection that interlocks with a complementary annular groove disposed in the wall of the bearing bore. 
     The thickness of the cam measured in the direction of the longitudinal center axis of the fixing tenon should be substantially identical to the thickness of the mounting plate. 
     According to a modified embodiment, the hinge can be adjusted, as mentioned above, in a third coordinate direction, namely perpendicular to the displacement in height and the gap spacing, for the purpose of changing the clearance of the door leaf on the front side of the frame. For this purpose, the hinge arm is fabricated as an element that is separately from the mounting plate, wherein its end facing the mounting plate is releaseably secured on a tab-like shoulder of the mounting plate which is bent essentially perpendicular into a position that is parallel to the closed inside of the door, so as to be moveable in its released position in a horizontal plane and fixable in selectable displacement positions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described hereinafter in detail with reference to an embodiment to be read in conjunction with the drawing, wherein 
         FIG. 1  is a longitudinal center cross-section through a furniture hinge according to the invention in the closed position, wherein section of the hinge for attachment to the door is formed as a insertion cup and mounted in a recess of a door leaf, and the section for attachment to the body is illustrated in the mounting position on a frame element of the cupboard body; 
         FIG. 2  is a view of only the section of the furniture hinge of the invention for attachment to the body as seen in the direction of the arrow  2  in  FIG. 1 ; 
         FIG. 3  is a view of the mounting plate of the section for attachment to the body according to  FIG. 2 , as seen in the viewing direction of  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the mounting plate, as seen in the direction of the arrows  4 — 4  in  FIG. 3 ; 
         FIG. 5  is a view of the mounting plate, as seen is a direction of the arrow  5  in  FIG. 4 ; 
         FIG. 6  is a top view—as seen in the viewing direction of FIG.  3 —of the fastening plate of the section for attachment to the body according to  FIG. 2 ; 
         FIG. 7  is a cross-sectional view through the fastening plate, as seen is a direction of the arrows  7 — 7  in  FIG. 6 ; 
         FIG. 8  is a side view of an eccentric adjusting element for adjusting the mounting plate on the fastening plate; 
         FIG. 9  is a view of the adjusting element, as seen in the direction of the arrow  9  in  FIG. 8 ; 
         FIG. 10  is a view of the adjusting element, as seen in the direction of the arrow  10  in  FIG. 8 ; 
         FIG. 11  is a side view of the fixing tenon, which can be used to fasten the section intended for attachment to the body of  FIG. 2  on a frame element; 
         FIG. 12  is a cross-sectional view of the fixing tenon, as seen in the direction of the arrows  12 — 12  in  FIG. 11 ; 
         FIG. 13  is a view of the fixing tenon, as seen is a direction of the arrows  13  in  FIG. 11 ; and 
         FIG. 14  shows the fixing tenon in a partial cross-section indicated in  FIG. 13  by the arrows  14 — 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The furniture hinge illustrated in FIG.  1  and having the reference numeral  10  is designed to couple a door leaf  12  to a cupboard body whose front, which is to be closed by the door leaf  12 , is narrowed by a inwardly projecting frame formed of strip-like frame elements.  FIG. 1  shows a section of a frame element  16  projecting inwardly from the cupboard side wall  14 , with the hinge  10  to be secured to the front face  18  of the body facing away from the walls. The exemplary hinge  10 , shown here as a single-hinged hinge, has a element  20  for attachment to the door in form of an insertion cup that can be mounted in a recess  19  disposed on the backside of the door leaf  12  and a pivotable element  22  for attachment to the body that can be rotated about a support pin  21  disposed inside the insertion cup. 
     The element  22  for attachment to the body which in the present example is formed of three pieces, has a hinge arm  24  with an end portion that is disposed in the insertion cup  20  and includes a bearing loop  26  surrounding with the above-mentioned bearing pin  21 . On the other end facing the body, the hinge arm is adjustably supported on a mounting plate  28  ( FIGS. 3  to  5 ) which has a plate-like fastening section  28   a  and a tab-like shoulder  28   b  extending essentially perpendicular thereto. A slot-like elongated through opening  30  is provided in the fastening section  28   a . A threaded bore  28   c  is provided in a sleeve-like embossed center region disposed in the tab-like shoulder  28   b , into which the threaded shank  27   a  of a fastening screw  27  can be screwed. The fastening screw  27  is guided through a longitudinal slot  24   a  ( FIG. 1 ) in the end region of the hinge arm  24 . When the fastening screw  27  is tightened, the head  27   b  of the fastening screw  27  urges the hinge arm  24  into firm contact with the tab-like shoulder  28   b . Conversely, when the fastening screw  27  is unscrewed, the hinge arm and the insertion cup together with the door leaf  12  can be displaced in a direction indicated in  FIG. 1  by the arrows a—a. 
     The plate-like fastening section  28   a  of the mounting plate  28  is arranged so as to contact a fastening plate  34  ( FIGS. 6 and 7 ) which, like the mounting plate  28  and the hinge arm  24 , are made of sheet metal by a stamping process. The fastening plate  34  has a flat plate-shaped section  34   a  which in the intended mounting position is disposed beneath the fastening section  28   a  of the mounting plate  28 . A fastening screw  32  extends through the elongated through opening  30  in the mounting plate  28  and through an elongated through opening  38  in the fastening plate  34 , holding them together on the end face  18  of the frame element  16 . A strip-like narrow section  38  of the front longitudinal edge of the fastening plate  34  facing the door leaf is bent, contacting the front side of the frame element  16  in the intended mounting position, thereby preventing the fastening plate  34  from rotating on the end face  18  of the frame element  16 , but allowing displacement in the longitudinal direction of the end face, i.e., in the direction of the arrows b—b of FIG.  2 —when the fastening screw  32  is unscrewed. 
     Each of the two edges of the mounting plate  28  that extend transversely to the longitudinal direction of the end faces, has a corresponding narrow strip-like section  40  that is a bent towards the end face  18  and grips around the transversely extending edges of the fastening plate  34 . The width of these strip-like sections  40  as measured perpendicular to the end face  18  is slightly smaller than the thickness of the material of the fastening plate  34 , so that their free edges cannot make contact with the end face  18  even when the fastening screw  32  is tightened. The strip-like sections  40  prevent the mounting plate  28  from rotating relative to the fastening plate  34 , but allow displacement in the direction of the arrows c—c (FIG.  2 ). 
     As seen in  FIG. 1 , the fastening screw  32  is not directly screwed into the frame element  16 , but instead is screwed into a fixing tenon  44  (depicted separately in  FIGS. 11  to  14 ) which can be anchored in the frame element  16  in a blind hole  46  ( FIG. 1 ) which is open towards the end face  18 . The fixing tenon  44  has a cylindrically shaped upper section  48  facing the fastening plate. The adjacent section  50  of the fixing tenon  44  is located inside the bore and has a plurality of successive parallel circumferential anchoring projections  52  with a saw-tooth-shaped cross-section. The fixing tenon  44  is further divided by a transverse slit  54  into two tenon halves  44   a ,  44   b  which are urged apart and deformed elastically when the fastening screw  32  is screwed in, so that the saw-tooth-shaped anchoring projections  52  pierce the peripheral wall of the blind hole  46  and anchor the fixing tenon  44  formfittingly in the blind hole  46 . Two narrow guide projections  56   a ,  56   b  project outwardly from the end face of the fixing tenon  44  facing the fastening plate. The width of the guide projections  56   a ,  56   b  is approximately identical to the width of the elongated through opening  36  of the fastening plate  34 , so that the guide projections also secure the fixing tenon against rotation in the through opening  36 . The fastening plate  34  can still be displaced relative to the fixing tenon over the length of the through opening  36 . The height of the guide projections is essentially identical to the thickness of the material of the fastening plate  34 . 
     A bearing bore  58  which rotatably supports a lug-like projection  60  of an adjusting element  62  is provided in the end region of the fixing tenon facing the fastening plate, as shown in  FIGS. 8  to  10 . 
     The adjusting element  62  has an upper elongated plate-shaped actuating section  64  which is wider than the width of the elongated through opening  30  in the mounting plate, so that the actuating section  64  laterally overlaps with the through opening  30  in the intended mounting position. A cam  66  with a limited circular orbit that is eccentrically offset relative to the subsequent pin-like lug  60  is provided directly on the underside of the actuating element  64 . The height of the cam  66  is essentially identical to the thickness of the material of the fastening sections  28   a  of the mounting plate. When the installation of the hinge is complete, the cam is arranged in a manner depicted in  FIG. 1  within the elongated through opening  30  of the mounting plate and supported on the opposing longitudinal sides of the through opening, with the end face of the cam facing the fixing tenon being supported on the top side of the fastening plate  34 . The shank of the fastening screw  32  is screwed through a through bore  68  provided in the adjusting element  62 , with the longitudinal center axis of the shank coinciding with the longitudinal center axis of the lug-like projection. The diameter of this through bore  68  is slightly greater than the outer diameter of the shank of the fastening screw  32  as measured on the outside threads, thereby preventing the thread of the fastening screw  32  from engaging with the adjusting element  62 , i.e., the adjusting element  62  can be rotated in the direction of the arrows d—d of  FIG. 3  without also turning the fastening screw. 
     A recess  70  is provided in the lever-like extended portion of the actuating section for receiving the tip of a screwdriver. To rotate the adjusting element  62 , a screwdriver can be inserted into the recess  70  to apply a force along the direction of the arrows d—d. When the adjusting element is rotated, the cam which is supported against the longitudinal edges of the through opening  30  of the mounting plate  28 , displaces the mounting plate  28  relative to the fastening plate  34  in the direction of the arrows c—c. 
     As shown with particularity in  FIG. 8 , the section of the lug-like projection  60  of the adjusting element  62  that engages with the bearing bore  58  has a peripheral annular projection  72 , which interlocks with a complementary annular groove  74  in the bearing bore  58 . After the hinge is installed, the fastening plate  34 , the mounting plate  28  and the adjusting element  62  are all held in the intended arrangement relative to one another, when the fastening screw  32  is either completely or partially unscrewed from the fixing tenon  44 . 
     It is therefore evident that when the fastening screw is unscrewed, the clamping connection between the end face  18  of the frame element  16  and the underside of the fastening plate  34  is also loosened, allowing an adjustment of the fastening plate in the longitudinal direction of the end face  18  of a corresponding frame element  16 —i.e., in the direction of the arrows b—b in FIG.  2 . When the fastening screw  32  is unscrewed, the height of a door leaf  12  that is connected to a cupboard body with a hinge according to the invention can be adjusted. To lock a selected height setting, the fastening screw is then again tightened, wherein the free end face of the cam urges the fastening plate  34  against the end face  18 , thereby locking the selected position. For adjusting the gap spacing of the door leaf, the adjusting element is rotated in the direction of the arrows d—d of  FIG. 2  by exerting a corresponding force in the adjustment direction with a tool inserted into the recess  70 . In this case, the fastening screw  32  that fixes the fastening plate  34  on the frame element  16  need not be unscrewed, i.e., the height and/or the gap spacing of the hinge can be adjusted independently, without running the risk of unintentionally also making changes in the other adjustment directions.