Abstract:
The invention is directed to a simply designed and easy-to-operate brake retardation apparatus in which a push rod is moveable in guides of a housing and possesses a section formed as a gear rack which meshes with a pinion of a shock absorber also retained in the housing.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a braking retardation apparatus for doors or the like consisting of a push rod which can be pressed into a housing against a braking force. 
     Brake retardation or absorption apparatuses of this type are used, for example, for the braking of doors and in particular of furniture doors just before their closed positions in order to brake the impact effect and to ensure the smoothest possible closing. Brake retardation apparatuses are used in particular when the doors and furniture doors are provided with closing devices which press them into their closed positions and hold them therein. Brake retardation apparatuses of the type given can, however, also be used for other parts, in particular furniture parts, for example drawers or flaps, to prevent these from reaching or impacting their end positions with force and disturbing noise. 
     From DE 197 17 937 A1 a brake and absorption element for moving furniture parts of the type first given is known where the housing consists of a cylinder-like sleeve and the push rod of a piston movable and spreadable in a radial direction therein, with the air contained in the cylinder cavity being compressed therein by pressing in the piston, with the piston being designed in such a way that the compressed air effects a radial spreading of the piston and thus its rubbing on the interior wall of the sleeve. 
     SUMMARY OF THE INVENTION 
     It is the object of the invention to provide a simply designed and easy-to-operate brake retardation apparatus of the type first given. 
     In accordance with the invention this object is solved by the push rod being movable in guides of the housing and possessing a section consisting of a gear rack which meshes with the pinion of a rotary shock absorber held in the housing. 
     Rotary shock absorbers of this type are known and commercially available. They normally consist of a shaft supported in a closed cylindrical housing which shaft carries a radially projecting plate or wing-like plates in the housing, which strokes over plates or projections in a fixed position relative to the housing in a non-contact manner, with a highly viscous fluid, for example silicone oil, being filled in the sealed housing. The pinion is set on a shaft journal led out of the housing. In accordance with a preferred embodiment it is provided that the push rod is acted upon by a spring in the push-out direction. Here, the spring can be designed to be so weak that it cannot overcome the retaining force of a closing device of a door. 
     Appropriately, the braking torque of the rotary shock absorber only acts in the push-in direction. Such rotary shock absorbers are also known. In these, the pinion is connected to the shaft carrying the wings by, for example, a freewheel acting in the push-out direction. In the closed state of the door, the rotary shock absorber exerts no action because the braking torque only occurs when there is a relative movement of the components. 
     The push rod can be guided in boreholes or passages of housing walls opposite each other. Appropriately, the spring consists of a compression spring enclosing a section of the push rod and clamped between the rear housing wall and the gear rack. 
     In accordance with another embodiment the object is solved by the push rod being the piston rod of a piston guided movably in a cylinder, by the cylinder being filled with a fluid, e.g. oil, and by the piston being provided with a throughway valve which opposes the extension of the piston with only a low resistance and the insertion with a high resistance, by a compression spring being clamped between the piston and the cylinder bottom and by a head being set on the piston rod. 
     The valve can, for example, consist of a flap valve or an annular valve body which expose a large borehole cross-section or a large cross-section of an opening of the piston when the piston extends and which, when the piston is pushed in, reach their closed positions in which only a small opening is revealed for the fluid which opening restricts the fluid for the generation of the braking effect. 
     Appropriately, the head consists of a cushion of elastomeric material so that the door impacts the piston rod with low noise and the cushion forms a buffer which thanks to its soft resilience does not damage the door. 
     In another aspect of the invention it is provided that the cylinder is fitted in a blind borehole, e.g. on the front side of a top panel of a cupboard and is supported on the head of a screw screwed into a thread of a sleeve located at the bottom of the blind borehole. By screwing in or unscrewing, the brake retardation apparatus can therefore be adjusted to the closing position of the door. 
     Appropriately, the borehole is fitted into a sleeve provided with a flange. This sleeve lines the outer edge region of the borehole and extends over the borehole edge with its flange. In the pressed-in state of the push rod, the head set on the piston rod then lies in this sleeve. 
     Another object of the invention comprises providing a braking apparatus for doors, windows or moving furniture parts, e.g. drawers, consisting of a push rod which can be pushed against a braking or absorbing force into a housing or cylinder, which braking apparatus is mounted in a particularly effective manner without creating an irritating appearance. 
     This object is solved in accordance with the invention by the housing or the cylinder being fixed to the front side of a frame, e.g. a rail, a top panel or a side panel of a cupboard, which is protruded over by the push rod provided with a fitted head. 
     In another aspect of the invention, the brake retardation apparatus in accordance with the invention can be fixed in a largely obscured manner not creating an irritating appearance to a position on a frame which is the closing frame for a door, a window, a drawer or the like. 
     Preferably the push rod and the housing or the cylinder possess one or more features of the type described above. 
     With pivotable furniture parts, for example, doors or flaps, the braking apparatus can be mounted at such a distance from the hinge side that it ensures a good braking effect and that the braking force of the braking apparatus is adapted in an optimum manner to the closing torque of the pivotable furniture part. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention are described in more detail below by means of the drawing in which 
     FIG. 1 shows a top view of the bottom and/or the top panel of a cupboard whose door is braked in the closing area by a brake retardation apparatus; 
     FIG. 2 shows the brake retardation apparatus of FIG. 1 with a removed top plate; 
     FIG. 3 shows a top view corresponding to FIG. 2 of the housing of the brake retardation apparatus with the push rod removed for better clarity; 
     FIG. 4 shows a view of the housing in the direction of the arrow A in FIG. 3; 
     FIG. 5 shows a section through a top panel of a cupboard in the region of a blind borehole accepting a cylinder of a brake retardation apparatus in the extended state of the braking piston; 
     FIG. 6 shows a representation corresponding to that of FIG. 5 in the inserted position of the braking piston; 
     FIG. 7 shows a side view of the cylinder with the head made of elastomeric material set on the piston rod of the braking piston; 
     FIG. 8 shows a top view of the bottom and/or the top panel of a cupboard whose door or flap is braked at an optimised distance from the hinge side by a brake retardation apparatus; 
     FIG. 9 shows a side view of a braking apparatus consisting of a cylinder having a front flange and a nut which can be screwed on; 
     FIG. 10 shows the braking apparatus of FIG. 9 mounted on the upper edge of a drawer opening. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 a view of the opening side of the bottom or top panel  1  of a cupboard  2  can be seen which can be closed by a door  3  which is hinged to a side panel  5  of the cupboard  2  by conventional hinges  4 , for example double-link hinges, with closing devices generating a closing pressure. To prevent any unwanted impacting of the door  3  in its closing position, brake retardation apparatuses  6  are fixed to the bottom or the top plate  1 , the push rods  7  of which brake retardation apparatuses extend over the opening plane of the cupboard  2  in the manner shown in the open position of the door so that it brakes a closing door in its closing region by the door pressing the push rod  7  inwards while consuming its rotary energy until the door reaches its closed position under the effect of absorption. 
     In FIGS. 1 and 2, the position of the door and the push rod  7  is shown by unbroken lines which they assume relative to each other when the door  3  hits the push rod  7  in the closing region. The closed position of the door with the inserted push rod  7  is shown in dash-dot lines. 
     The absorption apparatus  6  consists of a rectangular tub-shaped housing  8  whose open top side can be closed by a top plate  9  which can be pressed in, for example, in a non-positive manner. The housing  8  possesses in the plane of the bottom plate  10  lateral wing-like protrusions  11  which are provided with oblong holes  12  which form mounting boreholes for mounting screws  13 . Due to the oblong holes  12 , the brake retardation apparatus  6  can be aligned in the required manner in the axial direction of the push rod. 
     The front wall  14  of the housing  8  is provided with a rectangular opening  15  for the push rod  7  also rectangular in the cross-section, while the rear wall  16  possesses a round borehole  17  for the passing through of a pin-shaped part  18  of the push rod  7 . The push rod  7  rectangular in the cross-section is formed inside the housing  8  as a gear rack section  19 . The gear rack section  19  is provided at its rear end with a tapped hole into which the pin  18  is screwed. The pin  18  penetrates a compression spring  20  clamped between the rear front side of the gear rack section  19  and the edge of the borehole  17 . The pin  18  is provided at its end penetrating the borehole  17  with a head  21  which forms a stop on the rear housing wall  16  in the pushed-out position of the push rod  7 . 
     A cap  22  made of rubber or another absorbing material is fitted to the front end of the push rod  7 . 
     On a housing side panel  23 , there is fitted the cylindrical housing  24  of a rotary shock absorber  25  on whose journal extending over the housing a pinion  26  is wedged. The gear rack section of the push rod  7  meshes with the pinion  26  in the manner visible from FIG.  2 . The rotary shock absorber  25  is designed in such a way that the pinion only exerts a braking force on the push rod  7  in its push-in direction, while the push rod  7  can be pushed out again with practically no force by the compression spring  20 , for example by the installation of a freewheel in the rotary shock absorber. The compression spring  20  can therefore be designed with a very weak force so that its force can be overcome in the closed state of the door  3  by the closing mechanism of the hinge joints. 
     A second embodiment of the brake retardation apparatus in accordance with the invention is now described by means of FIGS. 5 to  7 . The brake retardation apparatus consists of a cylinder  30  in which a piston (not shown) is movably guided. The piston is connected to a piston rod  31  which penetrates a borehole provided with a sealing of a lid (not shown) of the cylinder. The cylinder  30  is filled with a fluid, for example oil of a suitable viscosity, which when the piston moves in the cylinder  30  enters into the front cylinder chamber from the rear one and vice versa. The piston is provided with one or more boreholes or with an annular opening bridged by bars which can be closed by a valve flap or a valve body in such a way that the boreholes or openings are opened in the push-out direction of the piston, while when the piston is pushed in, the flaps or the valve seat move in their closed positions in which these only open a throttle cross-section of such a size that the piston rod can only be pushed into the cylinder with a given resistance. 
     The piston is subjected to the pressure of a compression spring clamped between the piston and the cylinder bottom. This compression spring pushes the piston into the extended position visible in FIGS. 5 and 7. 
     On the piston  31 , a cap  32  made of an elastomeric material is fixed which ensures a gentle, damage-free pushing of the door  33  onto the piston rod  31 . 
     The door  33  is hinged to a side panel  35  of, for example, the cupboard by conventional link hinges  34 . The top panel  36  of the cupboard is provided with a blind borehole  37  in whose bottom a threaded sleeve  38  is located, for example made of brass. In the thread of the threaded sleeve  38 , a screw  39  is screwed on whose head  40  the cylinder  30  of the brake retardation apparatus is supported. In the blind borehole  37 , there is further fitted a sleeve  41  provided with a circumferential annular flange  42  which is supported on the borehole edge in the manner shown. In the pushed-in state of the piston rod  31 , the cap or the head  32  fitted on the piston rod  31  is located in the region of the sleeve  41 . 
     The force of the compression spring pushing out the piston is less than the force holding the door  33  closed so that the compression spring cannot press open the door by means of the piston and the piston rod  31 . 
     From FIG. 8, the assembly of a braking apparatus  50  onto the front side of a top or bottom panel of a cupboard body  51  can be seen, this being at an optimised distance A from the hinge side of the door or flap  52 . Depending on the distance A of the braking apparatus  50  from the hinge  53  of the door or flap, the braking apparatus acts in the closing region at a different angle of opening, with the door or flap acting on the braking apparatus with varying force in accordance with the lever length given by the distance A. The distance A is to be selected in dependence on the thickness or weight of the door or flap. Appropriately, the distance A corresponds at least roughly to the half of the width of the door as measured from the hinge side. 
     In the embodiment of FIG. 9, the braking apparatus  50  possesses a cylinder  51  provided with a front flange  52  for contact on a borehole edge. The cylinder  51  is provided with a thread  53  on which a nut  54  can be screwed. 
     The cylinder possesses at its front end a recess or clearance in which the head  56  made of elastically resilient material can dip in the manner shown by a broken line. 
     From FIG. 10, another assembly example of the braking apparatus  50  can be seen. A drawer opening is provided below its upper edge with a rail  57  fixed to the drawer body, which rail possesses a passage borehole in the manner shown. In the passage borehole, a braking apparatus of the type visible in FIG. 9 is fixed in such a way that the flange  52  is supported on the front edge region of the passage borehole. The braking apparatus  51  is secured in the passage borehole by the nut  54  screwed onto the cylinder  51 .