Abstract:
A sliding track structure includes an inner track, a middle track, an outer track, an inner ball bearing member, an outer ball bearing member, and a separation mechanism. The inner track is slidably joined with the middle track in conjunction with the inner ball bearing member. The outer track is slidably joined with the middle track in conjunction with the outer ball bearing member. The separation mechanism is disposed at a front end of the middle track to facilitate the separating of the outer track from the middle track.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to a drawer-sliding track structure, and more particularly to a drawer-sliding track structure with a separation mechanism allowing a drawer to be easily detached from a cabin, table and the like.  
         BACKGROUND OF THE INVENTION  
         [0002]    The conventional drawer-sliding structure is generally formed of a C-shaped outer slide track fastened to the vertical panel of a table, bureau, vanity, etc., a C-shaped inner track fastened to a drawer of the table, bureau, vanity, etc., a C-shaped middle track for coupling the inner track with the outer track, a first ball bearing member for fastening slidably the inner track with the middle track, and a second ball bearing member for fastening slidably the middle track with the outer track. The drawer can be thus drawn out and then pushed back into place by means of the drawer-sliding structure.  
           [0003]    U.S. Pat. No. 5,507,571 discloses a drawer-sliding structure of a telescopic construction, which comprises a middle track and an inner track disposed in the middle track. The inner track is provided with a separation mechanism by which the inner track can be separated from the middle track. This prior art structure is relatively wide and is therefore limited in use. There are other conventional structures which are relatively small in width and are devoid of an appropriate separation mechanism, due to the fact that the separation mechanism takes up a substantial space.  
         SUMMARY OF THE INVENTION  
         [0004]    The primary objective of the present invention is to provide a drawer-sliding structure with a separation mechanism which is simple in construction and small in size.  
           [0005]    A sliding track structure constructed according to the present invention comprises:  
           [0006]    a middle track having an H-shaped cross section, comprising a horizontal plate, and two vertical plates fastened respectively at two sides of said horizontal plate;  
           [0007]    an inner track adapted to be fastened with a table, bureau, vanity, or the like;  
           [0008]    an outer track adapted to be fastened with a drawer of the table, bureau, vanity, or the like;  
           [0009]    an inner ball bearing member mounted on one side of said two vertical plates of said middle track to enable said inner track to slide along a longitudinal direction of said middle track on said one side thereof; and  
           [0010]    an outer ball bearing member mounted on other side of said two vertical plates of said middle track to enable said outer track to slide along the longitudinal direction of said middle track on said other side thereof; wherein  
           [0011]    said outer track is provided at one end with an arresting piece to prevent separation of said outer ball bearing member from the one end of said outer track;  
           [0012]    said outer ball bearing member is provided with a folded portion close to said horizontal plate of said middle track for preventing said outer ball bearing member from separating from said middle track, wherein said folded portion  
           [0013]    wherein said horizontal plate of said middle track is provided with a separation mechanism which is able to be switched between a locking position and an unlocking position; when said separation mechanism is in said locking position, it will be in contact with a front end of said folded portion of said outer ball bearing member at the time when said outer track is slid along the longitudinal direction of said middle track toward a front end of said middle track, so that the outer track together with the outer ball bearing member are retained with the middle track; when said separation mechanism is in the unlocking position, said folded portion of said outer ball bearing member will move past said separation mechanism at the time when said outer track is slid along the longitudinal direction of said middle track toward the front end of said middle track, so that said outer track and said outer ball bearing member are separated from said middle track.  
           [0014]    Preferably, said separation mechanism comprises a sliding member having a stop portion and a sliding portion, said sliding member being received in a receiving hole on the horizontal plate and at the front end of said middle track such that said stop portion is jutted out of said receiving hole to be contiguous to said outer track, and further that said sliding portion is contiguous to said horizontal plate of said middle track, when said separation mechanism is in said locking position, wherein said stop portion is adapted to be in contact with said front end of said folded portion of said outer ball bearing member; and still further that said stop portion is not jutted out of said receiving hole, when said separation mechanism is in said unlocking position, wherein said stop portion is not able to be in contact with said front end of said folded portion of said outer ball bearing member. More preferably, said sliding member comprises a cube as said stop portion and a tongue extending from said cube, wherein said cube is partially jutted out of said receiving hole to be contiguous to said outer track, and said tongue is contiguous to said inner track, when said separation mechanism is in said locking position. Alternatively, said sliding member comprises a cube acting as said stop portion, and two inclined slots located in two opposite sides of said cube to act as said sliding portion; wherein said separation mechanism further comprises two inclined pillars located at two opposite sides of said receiving hole of said horizontal plate of said middle track, and said two inclined pillars are received in said two inclined slots.  
           [0015]    Preferably, said separation mechanism further comprises a carrying seat which is fastened with the front end of said horizontal plate of said middle track and is provided with a rectangular hole serving as said receiving hole, with said rectangular hole being equal in width to said cube and being greater in length to said cube; wherein said two inclined pillars are located in two opposite sides of said rectangular hole of said carrying seat.  
           [0016]    Preferably, said horizontal plate of said middle track is provided at the front end thereof with a rectangular fastening hole corresponding to said carrying seat; wherein said carrying seat is provided in the fringe with an insertion slot for fitting three side edges of said rectangular fastening hole; wherein said horizontal plate of said middle track is provided with a pliable confinement piece at the remaining side edges of said rectangular fastening hole for confining said carrying seat in said fastening hole.  
           [0017]    Preferably, said separation mechanism comprises a pivoting member, and a carrying seat which is fastened with the horizontal plate and at the front end of said middle track, said pivoting member comprising a stop portion and a tongue, said pivoting member being fastened pivotally with said carrying seat such that said tongue is jutted out of one side of the horizontal plate of said middle track, and that said stop portion is jutted out of other side of the horizontal plate of said middle track, and further that said stop portion is contiguous to said outer track, when said separation mechanism is in said locking position, wherein said stop portion is adapted to be in contact with said front end of said folded portion of said outer ball bearing member; and still further that said stop portion of said pivoting member is turned to said one side of the horizontal plate of said middle track, when said separation mechanism is in said unlocking position, wherein said stop portion is not able to be in contact with said front end of said folded portion of said outer ball bearing member. More preferably, said pivoting member comprises a right-angled triangular body serving as said stop portion, said tongue is extended upwardly and slantingly from a vertical side of said right-angled triangular body, and said carrying seat is provided at one end with two arms which are parallel to each other and are provided with a pivoting hole, wherein two pivots are provided on two opposite sides of said right-angled triangular body and at positions away from said vertical side of right-angled triangular body, and said pivoting member is fastened pivotally between said two arms with said two pivots being received in said pivoting holes, such that said tongue of said pivoting member is contiguous to one side of said carrying seat, and that said right-angled triangular body is exposed at other side of said carrying seat at the time when said separation is in said locking position; and said pivoting member is turned to said one side of said carrying seat, so that said right-angled triangular body is not exposed at other side of said carrying seat, when said separation mechanism is in said unlocking position  
           [0018]    The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 shows an exploded view of a first preferred embodiment of the present invention.  
         [0020]    [0020]FIG. 2 shows an exploded view of the sliding member of the separation mechanism and the middle track of the first preferred embodiment of the present invention.  
         [0021]    [0021]FIGS. 3A and 3B are sectional schematic view of the sliding member of the separation mechanism of the first preferred embodiment of the present invention in action.  
         [0022]    [0022]FIGS. 4A and 4B are partial top views of the sliding member of the separation mechanism of the first preferred embodiment of the present invention in action.  
         [0023]    [0023]FIG. 5 shows an exploded view of a second preferred embodiment of the present invention.  
         [0024]    [0024]FIG. 6A shows a schematic perspective view of the second preferred embodiment of the present invention in the locking state.  
         [0025]    [0025]FIG. 6B shows a schematic perspective view of the second preferred embodiment of the present invention in the unlocking state.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    As shown in FIGS. 1 and 2, the first preferred embodiment of the present invention comprises an inner track  10  adapted to be fastened with a table, bureau, or vanity, an outer track  30  adapted to be fastened with a drawer of the table, a middle track  20  having an H-shaped cross section, and two ball bearing members. Only one ball bearing member  40  is shown in the drawings. The two ball bearing members are symmetrical in construction and similar in function to each other, with one of the two ball bearing members (not shown in the drawings) being disposed between the inner track  10  and the middle track  20  such that the ball bearing member is confined by an arresting piece  11  of the inner track  10  and an arresting piece (not shown in the drawings) of the middle track  20 . Other one of the two ball bearing members  40  is mounted in the interior of the outer track  30  such that the ball bearing member  40  is located between two arresting pieces  31  and  32  of the outer track  30 , and that the ball bearing member  40  is capable of sliding in the interior of the outer track  30 .  
         [0027]    The inner track  10  has a flat plate  13  and two arcuate plates  14  extending vertically in the same direction from the flat plate  13 . Similarly, the outer track  30  has a flat plate  33  and two arcuate plates  34  extending vertically in the same direction from the flat plate  33 . The arresting pieces  11  and  12  of the inner track  10  are vertically extended from the flat plate  13  and made by punching. Similarly, the first arresting piece  31  of the outer track  30  is vertically extended from the flat plate  33  and is made by punching. The second arresting piece  32  of the outer track  30  is formed of two projections extending respectively from the two arcuate plates  34 . The outer track  30  is joined with the middle track  20  by pushing the outer track  30  to receive the middle track  20  in the ball bearing member  40  from the end having the second arresting piece  32 .  
         [0028]    The ball bearing members  40  are formed of a ball bearing seat and a plurality of ball bearings  43 . The ball bearing seat comprises a bottom plate  41  and two webs  42  extending vertically from the bottom plate  41 . The webs  42  are provided with a plurality of through holes for receiving the ball bearings  43 . The bottom plate  41  is provided in the midsegment with a folded portion  44 .  
         [0029]    The middle track  20  has a flat plate  21 , and two vertical plates  22  at ends of the flat plate  21 , each of which is provided with two arcuate slots  23  corresponding in location to the arcuate plates  14  of the inner track  10  and the arcuate plates  34  of the outer track  30 . The ball bearings  43  are held by the arcuate slots  23  and the arcuate plates  14  and  34 .  
         [0030]    The present invention comprises a separation mechanism  50  which is intended to separate the outer track  30  from the middle track  20 . The middle track  20  is provided at a front end of the flat plate thereof with a rectangular hole  51  and a pliable confinement piece  52  located at one side of the rectangular hole  51 . The separation mechanism  50  has a plastic frame  53  and a sliding member  56 . The sliding member  56  has a cube  561  (shown in FIG. 3A) which is equal in width to and smaller in length than the plastic frame  53 . The sliding member  56  further has two inclined slots  57 , an enlarged protrusion  58 , and a tongue  59 . The inclined slots  57  are located respectively in two opposite outer surfaces of the cube. The enlarged protrusion  58  is located in the top of the cube. The tongue  59  is extended from the rear side surface of the cube. The plastic frame  53  is provided in the outer edge with an insertion slot  54  into which three sides of the rectangular hole  51  are inserted. The plastic frame  53  is provided in two opposite inner sides with two inclined pillars  55 , which are fitted into the inclined slots  57  of the sliding member  57 . As shown in FIG. 2, the confinement piece  52  is pushed from one side toward other side to bring about a rectangular space, so as to enable the plastic frame  53  to be disposed in the rectangular hole  51 . Thereafter, the two inclined slots  57  of the sliding member  56  are aligned with the two inclined pillars  55  of the plastic frame  53 . The sliding member  56  is slid into the plastic frame  53  such that the enlarged protrusion  58  of the sliding member  56  comes in contact with the plastic frame  53 . Finally, the confinement piece  52  is pushed back to its original position, so as to fix the plastic frame  53 . As a result, the separation mechanism  50  is mounted on the middle track  20 , as shown in FIG. 3A. Similarly, as the sliding member  56  is pushed upwards, the sliding member  56  is raised slantingly such that the underside of the cube  561  of the sliding member  56  is level to the flat plate  21  of the middle track  20 , as shown in FIG. 3B. In light of the inclined plane of the tongue  59  and the engagement of the inclined slots  57  with the inclined pillars  55 , the sliding member  56  can be raised slantingly.  
         [0031]    As shown in FIG. 1, the inner track  10  is to be fastened to a table, bureau, vanity, etc. In order to mount the outer track  30  and the ball bearing member  40  on the middle track  20 , the sliding member  56  is pushed to locate at the positions as shown in FIGS. 3B and 4B, and the outer track  30  and the ball bearing member  40  are pushed to receive the middle track  20  from the end which is provided with the arresting piece  32 . The ball bearing member  40  is disposed between the outer track  30  and the middle track  20  such that the folded portion  44  of the bottom plate  41  of the ball bearing member  40  is jutted out of the flat plate  33  of the outer track  30 . As the front end of the folded portion  44  of the ball bearing member  40  is pushed beyond the sliding member  56 , the sliding member  56  is pushed downward to locate at the positions as shown in FIGS. 3A and 4A. As a result, the front end of the folded portion  44  will be stopped by the cube  561  of the sliding member  56  of the separation mechanism  50 , when the outer track  30  together with the ball bearing member  40  are pulled along the longitudinal direction and toward a front end of the middle track  20 , and thus the outer track  30  and the ball bearing member  40  can not escape from the middle track  20 .  
         [0032]    Assuming that a drawer is fastened with the outer track  30 , and that the drawer is drawn out fully, the outer track  30  is pulled out from the middle track  20 , while the middle track  20  is also being pulled out from the inner track  10 . The outer track  30  is prevented from being separated from the middle track  20  as shown in FIG. 3A. As the drawer is pushed back into place, the middle track  20  is retracted into the inner track  10  such that the middle track  20  is stopped by the first arresting piece  11  and/or the second arresting piece  12 . In the meantime, the outer track  30  is retracted such that the arresting piece  31  of the outer track  30  comes in contact with the front end of the middle track  20 .  
         [0033]    The outer track  30  can be separated from the middle track  20  by pulling out the outer track  30  from the middle track  20  to expose the sliding member  56 , which is then pushed upwards until such time when the underside of the cube  561  of the sliding member  56  is level to the flat plate  21  of the middle track  20 , thereby enabling the outer track  30  together with the ball bearing member  40  to be completely pulled out of the middle track  20 .  
         [0034]    As shown in FIGS. 5, 6A, and  6 B, a separation mechanism of the second preferred embodiment of the present invention comprises a  5  pivoting member  56 ′ and a carrying seat  53 ′. The pivoting member  56 ′ is formed of a stop portion  561  of a right-angled, triangular construction, a tongue  56  extending slantingly and upwardly from the vertical side of the stop portion, and two pivots  57 ′ located at the non-vertical sides of the stop portion  561 . The carrying seat  53 ′ is provided at one end with two arms  531  which are parallel to each other and are provided with a pivoting hole  532 . The pivoting member  56 ′ is fastened pivotally between the two arms  531  of the carrying seat  53 ′. The carrying seat  53 ′ is provided at other end with a recess (not shown in the drawings). The carrying seat  53 ′ can be fastened securely in the fastening hole  51  shown in FIG. 2.  
         [0035]    When the outer track  30  is joined with the middle track  20 , the tongue  59  of the pivoting member  56 ′ is contiguous to one side of the carrying seat  53 ′. The stop portion  561  is exposed at other side of the carrying seat  53 ′, as shown in FIG. 6A. The front end of the folded portion  44  of the bottom plate  41  of the ball bearing member  40  can be stopped by the vertical side of the stop portion  561 .  
         [0036]    In the process of separating the outer track  30  from the middle track  20 , the pivoting member  56 ′ is first so turned that the stop portion  561  is no longer exposed at the other side of the carrying seat  53 ′, as shown in FIG. 6B. As a result, the front end of the folded portion  44  of the bottom plate  41  of the ball bearing member  40  is not stopped by the vertical side of the stop portion  561 , thereby enabling the outer track  30  together with the ball bearing member  40  to be completely pulled out of the middle track  20 .