Abstract:
A safe guard device for the multi-section slide track assembly of drawers includes an inner slide track, an intermediate slide track, a limit member mounted on the intermediate slide track and an outer slide track. The inner slide track and the intermediate slide track are nested in the outer slide track and the limit member is used to engage and to position an end of the inner slide track. The limit member is able to pivot with respect to the intermediate slide track for engaging with or disengaging from the inner slide track. In retracing operation, the engagement of the inner slide track with the limit member provides with a temporary space on the inner slide track for accommodating fingers of an operator.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a safe guard device for a multi-section slide track assembly of drawers. More particularly, the present invention relates to a limit member mounted on an intermediate slide track so as to retain an inner slide track in retracting movement that will not damage fingers of an operator. 
   2. Description of the Related Art 
   Referring to  FIG. 8 , a conventional three-section slide track for a drawer includes an inner slide track (A), an intermediate slide track (B) and an outer slide track (C). The inner slide track (A) and the intermediate slide track (B) are nested in the outer slide track (C). A pair of ball tracks (D) and (E) are sandwiched in between any two of the inner slide track (A), the intermediate slide track (B) and the outer slide track (C) so as to smoothen slide movement. Moreover, the inner slide track (A) and the intermediate slide track (B) mount a retaining member (F) and a stop member (G) respectively for retaining in one-way direction while relatively extending them. The inner slide track (A) includes a narrowed portion (A 1 ) at its rear end and a bent portion (A 2 ) at its front end. Correspondingly, the outer slide track (C) includes an elastic barrier (H) at its rear end for engaging with the narrowed portion (A 1 ) of the inner slide track (A). 
   Further, the retaining member (F) is attached to an inner surface of the inner slide track (A), and provided with an engaging portion (F 1 ). The stop member (G) is mounted to a front end of the intermediate slide track (B), and formed with a protrusion (G 1 ). Users can draw out a keyboard or a component, which is attached to the inner slide track (A), for servicing. To prevent taking apart them by accident, the protrusion (G 1 ) of the stop member (G) is engaged with the engaging portion (F 1 ) of the retaining member (F) in place when user draws out the inner slide track (A) from the intermediate slide track (B). Alternatively, when user retracts the inner slide track (A), the bent portion (A 2 ) of the inner slide track (A) initially pushes the stop member (G) of the intermediate slide track (B) that causes a slide movement of the intermediate slide track (B) with respect to the outer slide track (C). Subsequently, the narrowed portion (A 1 ) of the inner slide track (A) may be securely engaged with the elastic barrier (H) of the outer slide track (C) after retracting a predetermined distance of the inner slide track (A). Consequently, the bent portion (A 2 ) of the inner slide track (A) is in contact with the stop member (G) of the intermediate slide track (B) and inserted into a front end of the outer slide track (C). 
   On the one hand the engagement of the retaining member (F) with the stop member (G) eliminates a careless release of the inner slide track (A) while drawing out it; and on the other hand the engagement of the narrowed portion (A 1 ) with the elastic barrier (H) carries out a secure position of the inner slide track (A) after retracting it. However, fingers held on the inner slide track (A) is easily run into the slide track before the bent portion (A 2 ) is in contact with the stop member (G) or inserted into the front end of the outer slide track (C). As a result, the fingers will be damaged if the return movement of the inner slide track (A) is too fast or user has no attention to release the inner slide track (A) in time. 
   The present invention intends to provide a safe guard device for a multi-section slide track assembly of drawers. The safe guard device includes a limit member mounted on the multi-section slide track assembly in such a way to mitigate and overcome the above problem. 
   SUMMARY OF THE INVENTION 
   The primary objective of this invention is to provide a safe guard device for a multi-section slide track assembly of drawers, which includes a limit member mounted on an intermediate slide track to temporarily position an inner slide track on the intermediate slide track. Thereby, an end of the inner slide track engages with the limit member that provides with a temporary space for accommodating fingers of an operator. 
   The secondary objective of this invention is to provide a safe guard device for a multi-section slide track assembly of drawers, which includes a limit member mounted on an intermediate slide track to temporarily position an inner slide track. Thereby, the entire structure of the multi-section slide track assembly is simplified. 
   The safe guard device for the multi-section slide track assembly of drawers in accordance with the present invention includes an inner slide track, an intermediate slide track, a limit member mounted on the intermediate slide track and an outer slide track. The inner slide track and the intermediate slide track are nested in the outer slide track and the limit member is used to engage and to position an end of the inner slide track. The limit member is able to pivot with respect to the intermediate slide track for engaging with or disengaging from the inner slide track. In retracing operation, the engagement of the inner slide track with the limit member provides with a temporary space on the inner slide track for accommodating fingers of an operator. 
   In design choice, the safe guard device in accordance with the present invention consists of an elastic thin lug, a guiding flange and at least one engaging hole. The elastic thin lug is provided with a bias force on the intermediate slide track and received in a slot of the intermediate slide track. The guiding flange is extended from the side edge of the limit member to engage with a press plate of the outer slide track for pivotal movement of the limit member. The engaging hole is corresponding to a protrusion of the intermediate slide track that ranges the movement of the engaging hole. 
   Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described in detail with reference to the accompanying drawings wherein: 
       FIG. 1  is an exploded perspective view of a three-section slide track assembly of drawers in accordance with a preferred embodiment of the present invention; 
       FIG. 2  is an assembled perspective view of the three-section slide track assembly of the drawers in accordance with the preferred embodiment of the present invention; 
       FIG. 3  is a lateral view of the three-section slide track assembly of the drawers in accordance with the preferred embodiment of the present invention in extending operation; 
       FIG. 4  is a lateral view of the three-section slide track assembly of the drawers in accordance with the preferred embodiment of the present invention in a first step of retracting operation; 
       FIG. 5  is a lateral view, similar to that shown in  FIG. 4 , of the three-section slide track assembly of the drawers in accordance with the preferred embodiment of the present invention in a second step of retracting operation; 
       FIG. 6  is a lateral view, similar to that shown in  FIG. 4 , of the three-section slide track assembly of the drawers in accordance with the preferred embodiment of the present invention in a third step of retracting operation; 
       FIG. 7  is a lateral view, similar to that shown in  FIG. 4 , of the three-section slide track assembly of the drawers in accordance with the preferred embodiment of the present invention in a fourth step of finally retracting operation; and 
       FIG. 8  is an exploded perspective view of a conventional three-section slide track in accordance with the prior art. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1 and 2 , it depicts that a three-section slide track assembly of drawers has a safe guard device. The three-section slide track assembly of drawers in accordance with a preferred embodiment of the present invention comprises an inner slide track  1 , an intermediate slide track  2  and an outer slide track  3 , each of which has a conventional configuration. The inner slide track  1 , the intermediate slide track  2  and the outer slide track  3  are rigid and strong to withstand normal use. In retracting operation, the inner slide track  1  and the intermediate slide track are nested in the outer slide track  3 . 
   To reduce the running abrasion in use, a pair of ball tracks  4  and  5  are sandwiched in between any two of the inner slide track  1 , the intermediate slide track  2  and the outer slide track  3  so as to smoothen slide movement. However, the entire structure is designed to have as low a friction characteristic as possible. In extending operation, the inner slide track  1  is able to extend a predetermined distance in longitudinal direction with respect to the intermediate slide track  2 . Similarly, the intermediate slide track  2  is able to extend a predetermined distance in longitudinal direction with respect to the outer slide track  3 . To avoid a careless release of the inner slide track  1 , a conventional retaining member is provided on the inner slide track  1 . 
   Although only the retaining construction of the inner slide track  1  has been discussed, it will be appreciated that the inner slide track  1  includes known structures such as a retaining member, a stop member and the like etc. 
   Referring again to  FIGS. 1 and 2 , the intermediate slide track  2  includes a limit member  6  mounted thereon in proper, thereby constituting the safe guard device. Construction of the limit member  6  shall be described in detail. 
   The limit member  6  employs an elongated piece provided with a bent flange (not labeled) on a first side edge. The limit member  6  further consists of an assembling hole  61 , an elastic thin lug  62 , a guiding inclined flange  63 , at least one engaging hole  64  and an engaging distal end  65 . Preferably, the assembling hole  61  is formed on a medium section of the limit member  6  and adapted to receive a positioning member  7  for mounting on the end of the intermediate slide track  2  and allowing pivotal movement with respect to the intermediate slide track  2 . Correspondingly, the intermediate slide track  2  includes an assembling hole  22  aligned with the assembling hole  61  of the limit member  6  and also adapted to receive the positioning member  7  when assembled with the limit member  6 . Further preferably, the elastic thin lug  62  is integrally formed on a second side edge of the limit member  6  and provided with a bias force on the intermediate slide track  2 . Correspondingly, the intermediate slide track  2  includes a slot  21  to receive the elastic thin lug  62  of the limit member  6  when assembled. In design choice, it will be appreciated that the elastic thin lug  62  can be substituted by a spring. Next, the guiding flange  63  is extended and protruded from the side edge of the limit member  6 . Correspondingly, the outer slide track  3  includes a press plate  31  at its end to engage with the guiding flange  63  of the limit member  6  in retracting operation. Next, the limit member  6  preferably includes a pair of the engaging holes  64  at either side of the assembling hole  61 . Correspondingly, the intermediate slide track  2  preferably includes a pair of protrusions  23  to range the movement of the engaging holes  64  of the limit member  6 . 
   Turning now to  FIG. 3 , it depicts that the three-section slide track assembly is extended. Extending operation of the three-section slide track assembly shall be described in detail. 
   When the inner slide track  1  is drawn out from the intermediate slide track  2  and the outer slide track  3 , the guiding flange  63  of the limit member  6  is disengaged from the press plate  31  of the outer slide track  3 . Thus, the elastic thin lug  62  automatically biases the limit member  6  to rotate a slightly angular movement. Consequently, the engaging distal end  65  of the limit member  6  abuts against a side edge of the intermediate slide track  2  to thereby confine the relatively retracting movement of the inner slide track  1 . 
   Turning now to  FIG. 4 , it depicts that the three-section slide track assembly is retracted in the first step. Retracting operation of the inner slide track  1  shall be described in detail. 
   When the inner slide track  1  is initially inserted a predetermined distance into the intermediate slide track  2 , an end of the inner slide track  1  is engaged with the engaging distal end  65  of the limit member  6  and thus temporarily positioned on the intermediate slide track  2 . Consequently, the other end of the inner slide track  1  provides with a temporary space with a specific length (L) for accommodating fingers of an operator. In other words, the retraction of the inner slide track  1  into the intermediate slide track  2  has not completed yet. Once the inner slide track  1  is engaged with the limit member  6 , it alerts the operator to release his fingers from the inner slide track  1 . 
   Turning now to  FIG. 5 , it depicts that the three-section slide track assembly is retracted in the second step. Retracting operation of the inner slide track  1  and the intermediate slide track  2  shall be described in detail. 
   Subsequently, the combination of the inner slide track  1  and the intermediate slide track  2  is successively pushed into the outer slide track  3 . Before the combination of the inner slide track  1  and the intermediate slide track  2  is retracted into the outer slide track  3 , the guiding flange  63  of the limit member  6  is engaged with the press plate  31  of the outer slide track  3  for unlocking of it. As a result, the operator must further act an additional force to push the inner slide track  1  that carries out the disengagement of the inner slide track  1  from the limit member  6  for retracting operation. At this time, the operator must prepare releasing his fingers from the inner slide track  1  for safety purpose. 
   Turning now to  FIG. 6 , it depicts that the three-section slide track assembly is retracted in the third step. Retracting operation of the inner slide track  1  and the intermediate slide track  2  shall be described in detail. 
   Subsequently, the combination of the inner slide track  1  and the intermediate slide track  2  is successively pushed into the outer slide track  3 . Once the press plate  31  of the outer slide track  3  has pressed and passed through the guiding flange  63  of the limit member  6 , the limit member  6  automatically releases the inner slide track  1  and allows it to retract into the intermediate slide track  2 . 
   Turning now to  FIG. 7 , it depicts that the three-section slide track assembly is completely retracted in the fourth step. Finally retracting operation of the inner slide track  1  and the intermediate slide track  2  shall be described in detail. 
   Finally, once the limit member  6  releases the inner slide track  1 , the operator can carefully push the inner slide track  1  and the intermediate slide track  2  into the outer slide track  3  without damaging the fingers. The remained length (L) of the inner slide track  1 , as shown in  FIGS. 4 through 6 , is retracted into the intermediate slide track  2 . Consequently, the inner slide track  1  and the intermediate slide track  2  are nested in the outer slide track  3  and the three-section slide track assembly is completely retracted. 
   Although the invention has been described in detail with reference to its presently preferred embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.