Sliding device for drawer

Abstract

Disclosed herein is a sliding device for guiding a drawer such that the drawer is extended from or retracted into a storage body. The sliding device includes sliding rails each having a pair of flanges, and balls slidably connecting the sliding rails to each other. Each flange includes a raceway in which a portion of the corresponding ball is disposed. The raceway guides the ball such that the ball rolls in a direction of extension or retraction of the drawer. The raceway includes a bent part and support surfaces. The bent part extends parallel to the direction of extension or retraction of the drawer. The bent part is concave in a direction in which the ball is inserted into the raceway. The support surfaces are disposed forming a symmetric structure with respect to an imaginary line connecting a center point of the ball to the bent part.

1 . A sliding device for guiding a drawer such that the drawer is extended from or refracted into a storage space formed in a storage body, the sliding device comprising:
 a plurality of sliding rails each having a pair of flanges; and   a plurality of balls slidably connecting the sliding rails to each other,   wherein each of the flanges comprises a raceway in which a portion of the corresponding ball is disposed, the raceway guiding the ball such that the ball rolls in a direction of extension or retraction of the drawer,   wherein the raceway comprises:   a bent part extending parallel to the direction of extension or retraction of the drawer, the bent part being concave in a direction in which the ball is inserted into the raceway; and   a plurality of support surfaces disposed forming a symmetric structure with respect to an imaginary line connecting a center point of the ball to the bent part, the support surfaces supporting the ball thereon.   
     
     
         2 . The sliding device of  claim 1 , wherein the support surfaces comprise a pair of support surfaces. 
     
     
         3 . The sliding device of  claim 2 , wherein each of the pair of support surfaces has a planar shape. 
     
     
         4 . The sliding device of  claim 2 , wherein each of the pair of support surfaces has a curved shape that is concave toward a portion thereof making contact with the ball. 
     
     
         5 . The sliding device of  claim 4 , wherein a radius of curvature of the support surface ranges from more than 50% of a diameter of the ball to 60% of the diameter of the ball. 
     
     
         6 . The sliding device of  claim 3 , wherein each of the pair of support surfaces has therein a support depression in which a portion of the ball is disposed, the support depression extending parallel to the direction of extension or retraction of the drawer. 
     
     
         7 . The sliding device of  claim 6 , wherein a radius of curvature of the support depression ranges from 50% of a diameter of the ball to 60% of the diameter of the ball. 
     
     
         8 . The sliding device of  claim 6 , wherein the support depression has a radius of curvature corresponding to a radius of the ball so that the support depression comes into line contact with the ball. 
     
     
         9 . The sliding device of  claim 1 , wherein a space is defined between the bent part and the corresponding ball. 
     
     
         10 . The sliding device of  claim 4 , wherein each of the pair of support surfaces has therein a support depression in which a portion of the ball is disposed, the support depression extending parallel to the direction of extension or retraction of the drawer. 
     
     
         11 . The sliding device of  claim 5 , wherein each of the pair of support surfaces has therein a support depression in which a portion of the ball is disposed, the support depression extending parallel to the direction of extension or retraction of the drawer.