Abstract:
A self braking door slide mechanism particularly adapted for use with cabinets that have front doors that open upwardly and are retracted using the slide mechanism to a position in which the door is aligned with the top of the cabinet in either an over or under top position. A dampening cylinder extends between the top of the cabinet and the door to slow its downwardly hinging action when the door is being closed. Auxiliary brake pads are also provided on a stationary slide member which bear against the moving portion of the slide mechanism to slow the sliding action during closing due to the force of the dampening cylinder.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation of application Ser. No. 08/520,952, filed Aug. 30, 1995 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to an improvement in wall-mounted cabinets of the type employed in offices, laboratories and the like. In one type of prior art wall cabinet with a stored door feature, the door generally slides to a stored position above the cabinet itself. Other prior art cabinets also utilize this feature and in these embodiments the door slides into a stored position inside the cabinet, either at the top or at the side of the cabinet. The cabinet doors of the over the top variety have a drawback in that when the door is slid forward to close the enclosure, the weight of the door tends to cause the door to accelerate and swing rapidly downwardly and slide forwardly at the same time creating the possibility of striking the person who is attempting to close the cabinet causing pain and possible injury. 
     SUMMARY OF THE INVENTION 
     The over the cabinet door assembly of this invention is significantly superior to prior art cabinets in that the door of the cabinet is equipped in such a way as to allow the door to be easily raised and moved to a stored position while requiring minimal effort at any point during movement along the path of closure. The assembly also has the added feature that the hardware is mostly hidden from view when it is in the stored position. When the door is moved forward to bring it to the closed position, a dampening mechanism is provided which extends between the enclosure and the door to retard and slow the door in its forward sliding motion and downward rotation motion to the closed position. 
     The foregoing is accomplished in accordance with the present invention, by providing an enclosure having a door which is slidably and hingedly retractable from a closed to an open position. The door comprises at least one ball bearing slide mechanism attached to the interior side of the door and a hinge mechanism attached at one side to the enclosure and to the slide mechanism at the end of the slide mechanism adjacent to the top of the enclosure. A motion dampening mechanism extends between the slide and the underside of the cabinet whereby the closing movement motion of the door is substantially retarded and slowed by the dampening mechanism as it swings and slides downwardly and rotates toward the enclosure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Many of the intended advantages of the present invention would be more readily apparent and better understood as the following detailed description is considered in connection with the accompanying drawing in which 
     FIG. 1 is a perspective view of a portion of an enclosure door and slide mechanism and attendant dampening mechanism according to the present invention in the raised position before being slid over the top of the enclosure to the open position; 
     FIG. 2A is a sectional view of the door slide with dampening mechanism in the closed door position; 
     FIG. 2B is a sectional view of the door slide with dampening mechanism in the open door position; 
     FIG. 3 is a perspective view of an enclosure according to the present invention wherein the door is equipped with the pair of slide mechanisms and a pair of dampening mechanisms to enable the door to be opened and slid over the top of the enclosure to the fully open position; and 
     FIG. 4 is a sectional view of the slide mechanism taken along lines 4--4 of FIG. 1. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In FIGS. 1 to 3 as shown, a cabinet or enclosure according to the present invention generally designated 10 with the door 12 in the closed and partially open positions. The cabinet includes a pair of side walls 14 and 16 to which a top wall 18 and a bottom wall 20 are secured in any convenient well known fashion such as by screws, bolts, dowels, etc. The pair of side walls 14 and 16 and the top and bottom walls 18 and 20 form a rectangular cabinet to which door 12 is fixed and for which door 12 serves as a closure. Bracket means are provided at the rearward edges of each of the side walls to mount the enclosure to a wall or space dividing panel. 
     Any conventional mounting means may be employed with the cabinet and in one embodiment, mounting brackets 19 which include a plurality of T-shaped hooks which are compatible with conventional slotted standards employed in many modern modular space dividing systems are provided and are particularly suitable. Such space dividing systems are available from a number of manufacturers including Herman Miller and Steelcase. The cabinet may be provided with a back 17 or it may be backless when it is unnecessary for the cabinet itself to have its own rear wall. 
     The door member or closure 12 is affixed to the remainder of the cabinet by one or more hinge members 26 and slide mechanisms 25. Each of the hinge members 26 includes a plate 23 secured to the front edge of the top wall 18 and a second plate 27 that is secured to a stationary inner track member 32 which carries an inner ball bearing race 34. In an alternative embodiment shown in FIGS. 2A and 2B, an angle bracket 23 a is secured under top wall 18 and extends upwardly along the front edge to a hinge member 26 which is located in the same position as shown in FIG. 1. An outer movable track or channel member 36 is attached to the interior side or backside of the door 12 and extends for substantially the full height of the door as is best seen in FIG. 3. The outer movable track member 36 includes an outer ball bearing race 38. A plurality of ball bearings 40 are carried on a moving ball carriage 42 which locates the balls 40 between the inner race 34 and outer race 38. In the preferred embodiment, the length of moving ball carriage 42 is significantly greater than the length of its associated stationary inner track member 32. Furthermore, the stationary inner track member is shorter in length than either of the moving ball carriage 42 or the outer movable track member 36. The outer movable track members extend for substantially the full height of the door 12. This multi-track feature allows the door member to move in almost frictionless fashion from the closed position of FIG. 2A to the open position of FIG. 2B with little effort on the part of the person opening the cabinet. A pair of spaced hinge members 26 and slide mechanisms 25 (FIG. 3) allow the cabinet door to be raised and moved to a stored position by grasping the door at any point along the door bottom. The double track system provides for almost frictionless relative movement between the stationary track and the moving track through the multiple speed effect provided by the movable ball carriage. The movable ball carriage moves with respect to the fixed track at a first speed and the rotation of the balls doubles that speed in imparting movement to the movable track and hence door 12. A pair of stop flanges are formed on the underside of the inner stationary track member 32 which co-acts with a pair of raised stop members on the upper side of the ball carriage 42 to prevent the stationary track member from being overrun by the ends of the ball carriage. At each end of the fixed outer track member 36 is a raised stop or end 48 which has mounted on it a bumper 50 which serves to cushion the impact when either the end of the inner track member or the ball carriage reaches the end of its travel against the stop 48. 
     The present invention provides a dampening mechanism 52 which is attached to the underside of the cabinet at one end 54 and at its opposite end 55 to a hinged brake plate 61 attached to the stationary track member 32. The dampening mechanism is typically a fluid containing cylinder and piston or slide mechanism and can be any one of a number of products which are available from companies which make products referred to variously as gas cylinders, gas springs, dampers, damper cylinders, linear decelerators, non-cavitating dampers, adjustable velocity control mechanisms and hydraulic check cylinders. Manufacturers of such equipment include Ace Controls Inc., Farmington, Mich.; Deschnar Corporation, Santa Ana, Calif., AVM (Arvin), Marion, S.C., Stabilus Corp., Colmar, Pa.; Enidine, Orchard Park, N.Y.; and Camloc Co., Madison Heights, Mich. A non-cavitating damper such as manufactured by AVM is particularly suitable for this application. 
     As best seen in FIG. 2A with the door in the closed position, the dampening mechanism 52 is in its fully closed position with the piston 56 shown in ghosted representation in FIG. 2A retracted for its full length to the bottom of the cylinder 58. When the door is opened, the cylinder, being attached at its end adjacent the door to the slide mechanism, is extended, drawing the cylinder outwardly over the piston. This action of opening movement continues until the door has rotated approximately 90° to the horizontal position shown in FIG. 2B. As shown therein, the cylinder has now extended approximately half again as long as its original length from the end of the piston, and the entire dampening mechanism has likewise rotated approximately 90° from a position in FIG. 2A where the mechanism is nearly vertical to a position in FIG. 2B where it has moved past the horizontal. 
     When the door is in the position shown in FIG. 2B, it is then moved in the direction of the arrow toward the rear of the enclosure under the control of the user until the door has moved to the point where the slide is in the fully closed position while the dampening mechanism is in the fully extended position. In this position the door overlies the top of the enclosure and the front edge of the door extends a predetermined distance in front of the leading edge of the sidewalls, top and bottom of the enclosure corresponding to the length of the extended cylinder. 
     In closing the door, the dampening mechanism comes into full play as the door is slid forward and reaches a point where its center of gravity passes the leading edge of the enclosure. At this point, the weight of the door causes it to hinge downwardly and begin to slide forward on the slide mechanism. As the door is allowed to rotate toward the closed position, the weight of the door bears on the cylinder and piston dampening mechanism 52 and the dampening action takes place, slowing the rotation of the door at a rate controlled by the rate of deceleration determined by the specific rating of the dampening mechanism. 
     The action of the weight of the door on the cylinder causes an equal and opposite reaction and the dampening mechanism exerts a force against the brake plate 61 causing it to hinge forward and exert a braking action on the movable outer member of the slide mechanism. A brake pad 60 is provided on each side of the brake plate which makes frictional contact with the edges of the moving channel member 36 and produces braking action on the edges of member 36. 
     The brake pad members 60 are chosen of a material with a high coefficient of friction such that the downward sliding action of the slide mechanism is retarded by the frictional braking force exerted by the brake pads on the sliding channel member 36. 
     The cooperative action of the dampening mechanism and the auxiliary brake pads caused the door to slowly slide forward and slowly rotate toward the closed position at a controlled rate such that there is no free fall or rapid closure of the door. This eliminates a rapid movement of the door which frequently results in striking the user on the head or slamming shut on the hand of the user. 
     As will be apparent from the foregoing, the cabinet door slide and dampening mechanism of the present invention provides a simple and efficient means for providing an easily opened, easily closed cabinet with a much improved performance and elimination of the annoyance of the tendency of the door to slam or fall shut.