Chair With A Footrest Device

Abstract

A chair includes a base having two sideboards. Each sideboard includes first and second coupling portions respectively at rear and front portions thereof. A seat is mounted on the base. A third coupling portion and a fourth coupling portion are provided on each lateral side of the seat. Each fourth coupling portion is coupled to one of the second coupling portions of the base. The seat is movable in a longitudinal direction and has a front end supported by the second and fourth coupling portions. A positioning device is coupled with the third coupling portion of the seat and the base, providing support for the rear end of the seat. The positioning device positions the seat relative to the base. A backrest is mounted to a rear of the base and is pivotably connected to the rear end of the seat and the sideboards.

1 . A chair with a footrest device, comprising:
 a base adapted to be placed on a ground, wherein the base includes two sideboards extending in a longitudinal direction and spaced from each other in a width direction perpendicular to the longitudinal direction, wherein each of the two sideboards extends in a vertical direction perpendicular to the ground and the longitudinal direction and includes a front end and a rear end spaced from the front end in the longitudinal direction, wherein a front board is interconnected between the front ends of the two sideboards, wherein a rear board is interconnected between the rear ends of the two sideboards, wherein each of the two sideboards further includes a first coupling portion at a rear portion thereof substantially aligned with a buttock of a sitter sitting in the chair, wherein each of the two sideboards further includes a second coupling portion at a front portion thereof substantially aligned with two feet of the sitter, wherein each of the two sideboards further includes a pivotal seat on an inner face of the rear end thereof, and wherein each pivotal seat includes a first pivotal portion;   a seat mounted on top of the base, wherein the seat includes a front end and a rear end having a second pivotal portion, wherein the seat has a length in the longitudinal direction for supporting the buttock and two legs of the sitter, wherein the seat further includes two lateral sides, wherein each of the two lateral sides of the seat includes a third coupling portion aligned with the first coupling portion and a fourth coupling portion aligned with the second coupling portion, wherein each fourth coupling portion is coupled to one of the second coupling portions of the base, wherein the seat is movable in the longitudinal direction, wherein the front end of the seat is supported by the second and fourth coupling portions;   a positioning device coupled with the third coupling portion of the seat and the base, providing support for the rear end of the seat, wherein the positioning device positions the seat relative to the base; and   a backrest mounted to a rear of the base, wherein the backrest includes a lower end having a third pivotal portion pivotably connected to the second pivotal portion of the seat, wherein the backrest further includes two lateral sides, wherein each of the two lateral sides of the backrest includes a fourth pivotal portion at a lower portion thereof, and wherein each fourth pivotal portion is pivotably connected to one of the first pivotal portions of the base.   
     
     
         2 . The chair with a footrest device as claimed in  claim 1 , wherein each first coupling portion of the base includes a first through-hole, wherein the positioning device includes two rear guiding rods, two locking seats, and two control knobs, wherein each of the two rear guiding rods includes a front end pivotably connected to one of the third coupling portions of the seat, wherein each of the two rear guiding rods is slideably received in one of the two locking seats, wherein each of the two locking seats is switchable between a locking position in which a corresponding one of the two rear guiding rods is locked in place and an unlocking position permitting sliding movement of the corresponding one of the two rear guiding rods, wherein each of the two locking seats includes a follower rod at an outer side thereof, wherein each of the two control knobs is mounted outside of one of the first coupling portions of the base and includes a coupling rod extending through the first through-hole of one of the first coupling portions and coupled with the follower rod of one of the two locking seats, and wherein each of the two control knobs is operable to switch one of the two locking seats between the locking position and the unlocking positions. 
     
     
         3 . The chair with a footrest device as claimed in  claim 2 , wherein each third coupling portion of the seat includes an engaging plate having a pivotal hole, wherein the front end of each of the two rear guiding rods includes a pivotal hole, wherein two pivots are respectively extended through the pivotal holes of the third coupling portions and the pivotal holes of the two rear guiding rods. 
     
     
         4 . The chair with a footrest device as claimed in  claim 2 , wherein each first coupling portion of the base further includes a first plate having a strength greater than the two sideboards of the base, wherein each first plate is fixed on an inner face of one of the two sideboards, and wherein each first through-hole extends through one of the first plates. 
     
     
         5 . The chair with a footrest device as claimed in  claim 1 , wherein each pivotal seat includes an opening in an upper end thereof, wherein each third pivotal portion of the backrest is mounted below one of the pivotal seats, wherein each fourth pivotal portion includes a pivot inserted into the opening and pivotably connected to the first pivotal portion of one of the pivotal seats of the base. 
     
     
         6 . The chair with a footrest device as claimed in  claim 1 , wherein each second coupling portion of the base includes a second plate harder than the two sideboards, wherein each second plate is fixed on an inner face of one of the two sideboards, wherein each second plate includes a coupling tube formed on an inner face of the second plate, wherein each fourth coupling portion of the seat includes a front guiding rod extending in the longitudinal direction and a coupling seat mounted around the front guiding rod, wherein each front guiding rod includes two ends fixed to the seat, wherein each coupling seat has a connecting rod extending through the coupling tube of one of the second coupling portions of the base, and wherein each front guiding rod slides in a corresponding one of the coupling seats when the seat moves in the longitudinal direction. 
     
     
         7 . The chair with a footrest device as claimed in  claim 2 , further comprising at least one elastic element, wherein the at least one elastic element provides resistance to forward movement of the seat in the longitudinal direction and provides an elastic returning force for moving the seat rearward. 
     
     
         8 . The chair with a footrest device as claimed in  claim 7 , wherein the base includes at least one fifth coupling portion, wherein the positioning device includes at least one sixth coupling portion on at least one of the rear ends of the two rear guiding rods, wherein the at least one elastic element is a coil spring and has two tangs and respectively connected to the at least one fifth coupling portion and the at least one sixth coupling portion.