Sliding rail device

Abstract

A sliding rail device includes a first rail, a second rail and two supporting units. The first rail includes a first base wall, and two first side walls cooperating with the first base wall to define a first passage. Each of the first side walls has an engaging slot. The second rail engages the first passage, is movable relative to the first rail, and includes a second base wall and two second side walls. The two supporting units respectively and movably engage the engaging slots of the first side walls, and abut respectively and slidably against the second side walls. During movement of the second rail relative to the first rail, the supporting units are driven to respectively move along the engaging slots of the first side walls, and to move toward each other to tighten abutment of the supporting units against the second side walls.

What is claimed is: 
     
         1 . A sliding rail device comprising:
 a first rail that includes
 a first base wall, and 
 two first side walls extending respectively and transversely from opposite sides of said first base wall and cooperating with said first base wall to define a first passage, each of said first side walls having an engaging slot; 
   a second rail that engages said first passage, that is movable relative to said first rail, and that includes
 a second base wall, and 
 two second side walls extending respectively and transversely from opposite sides of said second base wall; and 
   two supporting units that respectively and movably engage said engaging slots of said first side walls, and that abut respectively and slidably against said second side walls;   wherein, during movement of said second rail relative to said first rail, said supporting units are driven to respectively move along said engaging slots of said first side walls, and to move toward each other to tighten abutment of said supporting units against said second side walls.   
     
     
         2 . The sliding rail device as claimed in  claim 1 , wherein:
 said sliding rail device further comprises two ball bearing strips, each of said ball bearing strips being movably disposed on a respective one of said first side walls, abutting against a respective one of said second side walls, and having a ball bearing strip slope;   each of said supporting units has a first supporting slope; and   during the movement of said second rail relative to said first rail, said ball bearing strips are driven to move to respectively abut said ball bearing strip slopes against said first supporting slopes of said supporting units, thereby driving said supporting units to respectively move along said engaging slots of said first side walls and to move toward each other to tighten the abutment of said supporting units against said second side walls.   
     
     
         3 . The sliding rail device as claimed in  claim 2 , wherein:
 each of said supporting units further has a second supporting slope that extends towards the respective one of said second side walls, and that abuts slidably against the respective one of said first side walls; and   during the movement of said second rail relative to said first rail, said supporting units are driven to respectively move along said engaging slots, and to move toward each other to tighten the abutment of said supporting units against said second side walls.   
     
     
         4 . The sliding rail device as claimed in  claim 3 , wherein:
 each of said supporting units includes
 a main body extending in a lengthwise direction of said first rail, abutting against the respective one of said first side walls and the respective one of said second side walls, and having said first and second supporting slopes, and 
 an engaging block extending from said main body into the respective one of said engaging slots; 
   for each of said supporting units, said first supporting slope is formed on an end of said main body that faces said ball bearing strip slope of the respective one of said ball bearing strips; and   for each of said supporting units, said second supporting slope extends from a junction of said engaging block and said main body away from said first supporting slope, and is inclined towards the respective one of said second side walls.