Sliding device for drawer

Abstract

A sliding device is disclosed for a drawer capable of reinforcing rigidity while reducing noise during operation by mixing and using a plurality of slide balls having different tensile strengths. The sliding device includes: a fixed rail fastened and fixed to a main body, a movable rail fastened and fixed to a storage body, and sliding on the fixed rail, an intermediate rail disposed between the fixed rail and the movable rail to guide the sliding movement of the movable rail, and ball assemblies disposed between the intermediate rail and the fixed rail and between the intermediate rail and the movable rail, respectively to move to be slidable, and provided with a plurality of slide balls having different tensile strengths, the slide ball having a large tensile strength being disposed at the outermost side thereof.

1 . A sliding device for a drawer comprising:
 a fixed rail fastened and fixed to a main body;   a movable rail fastened and fixed to a storage body, and sliding on the fixed rail;   an intermediate rail disposed between the fixed rail and the movable rail to guide the sliding movement of the movable rail; and   ball assemblies disposed between the intermediate rail and the fixed rail and between the intermediate rail and the movable rail, respectively to move to be slidable, and provided with a plurality of slide balls having different tensile strengths, the slide ball having a large tensile strength being disposed at the outermost side thereof.   
     
     
         2 . The sliding device for the drawer of  claim 1 ,
 wherein the intermediate rail comprises:   a plate part disposed between the fixed rail and the movable rail; and   contact parts provided at both sides of the plate part along the longitudinal direction, respectively, and formed with rolling surfaces so that the slide balls of the ball assembly are partially accommodated, and   wherein a plurality of rolling surfaces are formed to be spaced apart from each along the circumferential direction thereof at each of one side and the other side of the plate part.   
     
     
         3 . The sliding device for the drawer of  claim 2 ,
 wherein the ball assembly comprises:   a retainer provided in a ‘¬’ shape, and formed with a plurality of through holes at regular intervals in the longitudinal direction at both ends and edges thereof;   a first slide ball inserted into a first through hole formed in the end of one side of the retainer, and disposed on a first rolling surface formed to be curved at the edge of one side of the contact part;   a second slide ball inserted into a second through hole formed in the edge of the retainer, and disposed on a second rolling surface formed to be curved at the edge of the other side of the contact part; and   a third slide ball inserted into a third through hole formed in the end of the other side of the retainer, and disposed on a third rolling surface formed to be curved at the lower side of the second rolling surface.   
     
     
         4 . The sliding device for the drawer of  claim 3 ,
 wherein the retainer has the first through hole and the third through hole which are provided on the same line, and the second through hole which is provided between the first through hole and the third through hole.   
     
     
         5 . The sliding device for the drawer of  claim 3 ,
 wherein the first rolling surface, the second rolling surface, and the third rolling surface are formed to be curved at the same diameters, and   wherein the first slide ball, the second slide ball, and the third slide ball are provided at the same diameters.   
     
     
         6 . The sliding device for the drawer of  claim 3 ,
 wherein the first rolling surface and the second rolling surface are formed to be curved at the same diameters, and the third rolling surface is formed to be curved at a larger diameter than that of the second rolling surface, and   wherein the first slide ball and the second slide ball are provided at the same diameters, and the third slide ball is provided at a larger diameter than that of the second slide ball.   
     
     
         7 . The sliding device for the drawer of  claim 3 ,
 wherein the ball assembly has the slide balls disposed at both side ends which are larger in tensile strength than the slide balls located at the center side, among the plurality of first slide balls and third slide balls.   
     
     
         8 . The sliding device for the drawer of  claim 7 ,
 wherein the ball assembly has the slide balls disposed at both side ends which are larger in tensile strength than the slide balls located at the center side, among the plurality of second slide balls.   
     
     
         9 . The sliding device for the drawer of  claim 1 ,
 wherein the ball assembly has the slide balls having different tensile strengths whose difference is 400 MPa or more.   
     
     
         10 . The sliding device for the drawer of  claim 1 ,
 wherein the ball assembly has the slide ball having a large tensile strength which is made of a material having the tensile strength of 405 to 2500 MPa, and the slide ball having a small tensile strength which is made of a material having the tensile strength of 5 to 150 MPa.   
     
     
         11 . The sliding device for the drawer of  claim 1 ,
 wherein the fixed rail and the movable rail further comprise:   stoppers formed to protrude from the inner circumferential surfaces of the fixed rail and the movable rail, and limiting the movement so that the ball assembly slides only within a predetermined region.   
     
     
         12 . The sliding device for the drawer of  claim 1 ,
 wherein the intermediate rail further comprises:   a stopper limiting the movement so that the ball assembly slides only within a predetermined region.