Movable seat unit and movable seat

Abstract

A movable seat unit, including armrest side plates supported on the ground; a mechanical extension device including a seat frame configured to attach a seat portion and a backrest assembly disposed at a rear portion of the seat frame and configured to attach a backrest, where guide rails extending in a front-rear direction of the seat unit are provided on the armrest side plates, and the seat frame is slidably engaged with the guide rails; the backrest assembly includes a backrest mounting member and a guide chute member fixedly mounted relative to the armrest side plates, a lower end of the backrest mounting member is pivotally connected to a rear portion of the seat frame, and a middle portion of the backrest mounting member is provided with a guide pin configured to slidably engage with the guide chute.

What is claimed is: 
     
         1 . A movable seat unit, comprising:
 a pair of armrest side plates, arranged in parallel and supported on the ground;   a mechanical extension device, disposed between the pair of armrest side plates, the mechanical extension device comprising a seat frame configured to attach a seat portion and a backrest assembly disposed at a rear portion of the seat frame and configured to attach a backrest, wherein a guide rail extending in a front-rear direction of the seat unit is provided on each of the pair of armrest side plates, and the seat frame is slidably engaged with the guide rail; and   an electric drive unit, by means of which the seat frame is configured to slide front and rear relative to the pair of armrest side plates along the guide rail,   wherein the backrest assembly comprises a backrest mounting member and a guide chute member fixedly mounted relative to the pair of armrest side plates, the guide chute member is provided with a guide chute extending in the front-rear direction of the seat unit, an upper end of the backrest mounting member is attached to the backrest, a lower end of the backrest mounting member is pivotally connected to a rear portion of the seat frame, and a middle portion of the backrest mounting member is provided with a guide pin configured to slidably engage with the guide chute, such that a pivot point between the lower end of the backrest mounting member and the rear portion of the seat frame moves forward when the seat frame slides forward.   
     
     
         2 . The seat unit according to  claim 1 , wherein a highest point of the backrest has a tendency to move downward and forward when the seat frame slides forward. 
     
     
         3 . The seat unit according to  claim 1 , wherein the seat frame comprises two seat frame longitudinal beams extending in parallel in the front-rear direction of the seat unit and at least one seat frame cross beam transversely connected between the two seat frame longitudinal beams, wherein the seat frame longitudinal beams are slidably engaged with the guide rails. 
     
     
         4 . The seat unit according to  claim 3 , wherein the electric drive unit comprises a seat frame actuator acting between the pair of armrest side plates and the seat frame. 
     
     
         5 . The seat unit according to  claim 4 , wherein an end of the seat frame actuator is fixedly positioned relative to the pair of armrest side plates, and an opposite end of the seat frame actuator is connected to the seat frame cross beam, wherein extension and retraction of the seat frame actuator cause the seat frame to slide front and rear relative to the pair of armrest side plates. 
     
     
         6 . The seat unit according to  claim 4 , wherein the mechanical extension device further comprises a leg extension device pivotally connected to a front portion of the seat frame, a leg cross beam is connected between the leg extension devices, and the seat unit is configured to transform between a sitting position, a TV position, and a reclining position by means of the electric drive unit, wherein in the sitting position, the backrest is upright and the leg extension device is retracted below the seat portion, in the TV position, the leg extension device is extended in front of the seat portion, and in the reclining position, the leg extension device is extended in front of the seat portion, and the seat frame slides forward and drives the backrest to tilt at a larger angle. 
     
     
         7 . The seat unit according to  claim 6 , wherein the electric drive unit further comprises a leg actuator acting between the seat frame and the leg extension device. 
     
     
         8 . The seat unit according to  claim 7 , wherein an end of the leg actuator is connected to the seat frame cross beam, and an opposite end of the leg actuator is connected to the leg cross beam, wherein extension and retraction of the leg actuator cause the leg extension device to extend or retract. 
     
     
         9 . The seat unit according to  claim 3 , wherein the mechanical extension device further comprises a leg extension device pivotally connected to a front portion of the seat frame, a leg cross beam is connected between the leg extension devices, and the seat unit is configured to transform sequentially between a sitting position, a TV position, and a reclining position by means of the electric drive unit, wherein the backrest is upright and the leg extension device is retracted below the seat portion in the sitting position, the leg extension device is extended in front of the seat portion in the TV position, and the leg extension device is extended in front of the seat portion in the reclining position, the seat frame slides forward and drives the backrest to tilt at a larger angle, wherein the electric drive unit is configured as a seat actuator acting between the pair of armrest side plates and the leg extension device. 
     
     
         10 . The seat unit according to  claim 9 , wherein an end of the seat actuator is fixedly positioned relative to the pair of armrest side plates, and an opposite end of the seat actuator is connected to the leg cross beam, wherein extension and retraction of the seat actuator cause the leg extension device and the seat frame to act sequentially. 
     
     
         11 . The seat unit according to  claim 9 , wherein an adjustment stroke of the seat actuator is divided into two sequentially performed phases, the leg extension device moves relative to the seat frame in a first phase, and the seat frame slides relative to the pair of armrest side plates in a second phase. 
     
     
         12 . A movable seat, comprising the seat unit according to  claim 1 . 
     
     
         13 . A movable seat, comprising the seat unit according to  claim 2 . 
     
     
         14 . A movable seat, comprising the seat unit according to  claim 3 . 
     
     
         15 . A movable seat, comprising the seat unit according to  claim 4 . 
     
     
         16 . A movable seat, comprising the seat unit according to  claim 5 . 
     
     
         17 . A movable seat, comprising the seat unit according to  claim 6 . 
     
     
         18 . A movable seat, comprising the seat unit according to  claim 7 . 
     
     
         19 . A movable seat, comprising the seat unit according to  claim 8 . 
     
     
         20 . A movable seat, comprising the seat unit according to  claim 9 .