Seat cushion for chair and seat for chair including the same

Abstract

A seat cushion for a chair has a plurality of cushion grooves deformed a seat load of a user formed in a central portion of a lower surface thereof, the plurality of cushion grooves include: a plurality of main cushion grooves disposed in a plurality of rows in a front-rear direction and a left-right direction and spaced an equal interval from each other; and a plurality of sub-cushion grooves each connecting one of the plurality of main cushion grooves and formed in a straight shape with narrower widths and smaller depths than the plurality of main cushion grooves.

The invention claimed is: 
     
         1 . A seat cushion for a chair, which has a plurality of cushion grooves deformed a seat load of a user formed in a central portion of a lower surface thereof,
 wherein the plurality of cushion grooves include:   a plurality of main cushion grooves disposed in a plurality of rows in a front-rear direction and a left-right direction and spaced an equal interval from each other; and   a plurality of sub-cushion grooves each connecting one of the plurality of main cushion grooves and formed in a straight shape with narrower widths and smaller depths than the plurality of main cushion grooves.   
     
     
         2 . The seat cushion of  claim 1 , wherein vertical thicknesses from upper ends of the plurality of main cushion grooves to an upper end of the seat cushion ranges from 30 to 40 mm. 
     
     
         3 . The seat cushion of  claim 2 , wherein depths of the plurality of main cushion grooves is greater than half of the vertical thickness of the seat cushion. 
     
     
         4 . The seat cushion of  claim 1 , wherein the plurality of main cushion grooves and the plurality of sub-cushion grooves are symmetrical in a left-right direction with respect to a central portion of the seat cushion in the left-right direction, and
 the plurality of sub-cushion grooves are disposed diagonally to be closer to the central portion of the seat cushion in the left-right direction forward.   
     
     
         5 . The seat cushion of  claim 4 , wherein the plurality of main cushion grooves include:
 a plurality of first main cushion grooves disposed to be spaced apart from each other in the front-rear direction in the central portion of the seat cushion in the left-right direction;   a plurality of second main cushion grooves spaced apart from the plurality of first main cushion grooves in a left direction and disposed to be spaced apart from each other in the front-rear direction; and   a plurality of third main cushion grooves spaced apart from the plurality of first main cushion grooves in a right direction and disposed to be spaced apart from each other in the front-rear direction, and   the plurality of sub-cushion grooves include:   a plurality of first sub-cushion grooves each connecting one of the plurality of first main cushion grooves to one of the plurality of second main cushion grooves; and   a plurality of second sub-cushion grooves each connecting one of the plurality of first main cushion grooves to one of the plurality of third main cushion grooves.   
     
     
         6 . The seat cushion of  claim 5 , wherein the plurality of first sub-cushion grooves each has a front end connected to one of the plurality of first main cushion grooves and a rear end connected to one of the plurality of second main cushion grooves disposed in a row immediately behind one of the plurality of first main cushion grooves to which a front end of each of the plurality of first sub-cushion grooves is connected and is disposed diagonally, and
 the plurality of second sub-cushion grooves each has a front end connected to one of the plurality of first main cushion grooves and a rear end connected to one of the plurality of third main cushion grooves disposed in a row immediately behind one of the plurality of first main cushion grooves to which a front end of each of the plurality of second sub-cushion grooves is connected and is disposed diagonally.   
     
     
         7 . The seat cushion of  claim 5 , wherein the plurality of main cushion grooves further include:
 a plurality of fourth main cushion grooves spaced apart from the plurality of second main cushion grooves in the left direction and disposed to be spaced apart from each other in the front-rear direction; and   a plurality of fifth main cushion grooves spaced apart from the plurality of third main cushion grooves in the right direction and disposed to be spaced apart from each other in the front-rear direction, and   the plurality of sub-cushion grooves further include:   a plurality of third sub-cushion grooves each connecting one of the plurality of second main cushion grooves to one of the plurality of fourth main cushion grooves; and   a plurality of fourth sub-cushion grooves each connecting one of the plurality of third main cushion grooves to one of the plurality of fifth main cushion grooves.   
     
     
         8 . The seat cushion of  claim 7 , wherein the plurality of first sub-cushion grooves each has a front end connected to one of the plurality of first main cushion grooves and a rear end connected to one of the plurality of second main cushion grooves disposed in a row immediately behind one of the plurality of first main cushion grooves to which a front end of each of the plurality of first sub-cushion grooves is connected and is disposed diagonally,
 the plurality of second sub-cushion grooves each has a front end connected to one of the plurality of first main cushion grooves and a rear end connected to one of the plurality of third main cushion grooves disposed in a row immediately behind one of the plurality of first main cushion grooves to which a front end of each of the plurality of second sub-cushion grooves is connected and is disposed diagonally,   the plurality of third sub-cushion grooves each has a front end connected to one of the plurality of second main cushion grooves and a rear end connected to one of the plurality of fourth main cushion grooves disposed in a row immediately behind one of the plurality of second main cushion grooves to which a front end of each of the plurality of third sub-cushion grooves is connected and is disposed diagonally, and   the plurality of fourth sub-cushion grooves each has a front end connected to one of the plurality of third main cushion grooves and a rear end connected to one of the plurality of fifth main cushion grooves disposed in a row immediately behind one of the plurality of third main cushion grooves to which a front end of each of the plurality of fourth sub-cushion grooves is connected and is disposed diagonally.   
     
     
         9 . The seat cushion of  claim 7 , wherein the number of each of the plurality of fourth main cushion grooves and the plurality of fifth main cushion grooves is one less than the number of each of the plurality of first main cushion grooves, the plurality of second main cushion grooves, and the plurality of third main cushion grooves, and
 main cushion grooves disposed at foremost portions of each of the plurality of fourth main cushion grooves and the plurality of fifth main cushion grooves are disposed to be spaced apart from main cushion grooves disposed second from the front of each of the plurality of first main cushion grooves, the plurality of second main cushion grooves and the plurality of third main cushion, in the left-right direction.   
     
     
         10 . The seat cushion of  claim 1 , wherein the plurality of main cushion grooves are formed as circular grooves. 
     
     
         11 . The seat cushion of  claim 1 , wherein the plurality of main cushion grooves are formed as polygonal grooves. 
     
     
         12 . The seat cushion of  claim 1 , wherein an insertion groove into which a seat plate supporting the seat cushion is inserted is formed in a lower surface of the seat cushion, and
 the plurality of cushion grooves are formed in an upper surface of the insertion groove.   
     
     
         13 . The seat cushion of  claim 12 , wherein an edge groove into which an edge protrusion formed at an edge of an upper surface of the seat plate is inserted is formed in an edge of the upper surface of the insertion groove, and
 the plurality of cushion grooves are formed inside the edge groove of the upper surface of the insertion groove.   
     
     
         14 . A seat for a chair, comprising:
 a seat cushion having a plurality of cushion grooves deformed a seat load of a user formed in a central portion of a lower surface thereof; and   a seat plate supporting the seat cushion,   wherein the plurality of cushion grooves include:   a plurality of main cushion grooves disposed in a plurality of rows in a front-rear direction and a left-right direction; and   a plurality of sub-cushion grooves each connecting one of the plurality of main cushion grooves and formed in a straight shape with narrower widths and smaller depths than the plurality of main cushion grooves.   
     
     
         15 . The seat of  claim 14 , wherein an insertion groove into which the seat plate is inserted is formed in a lower surface of the seat cushion, and
 the plurality of cushion grooves are formed in an upper surface of the insertion groove.