Chair with aid in lying back and getting up

Abstract

A chair includes a base, a seat, a backrest pivotally connected to a rear end of a seat frame of the seat, and a transmission mechanism including a motor, a telescopic rod actuated by the motor to move in a retracting direction and an extending direction, and a transmission plate. A connecting rod is pivotally connected between a lower end of the backrest frame and the transmission plate. The telescopic rod is directed to a position below a central portion of the seat. The transmission plate is pivoted to the central portion of the seat, the second end of the connecting rod, and the telescopic rod at different portions thereof. When the telescopic rod is retracted, the top support portion of the transmission plate presses against the seat frame to make the rear end of the seat frame move upward and forward.

1 . A chair comprising: 
 a base ( 1 ;  71 ) comprising a front end and a rear end;    a seat ( 2 ;  72 ) comprising a seat frame ( 21 ;  721 ), the seat frame ( 21 ;  721 ) including a central portion and a rear end;    a backrest ( 3 ;  73 ) comprising a lower end pivotally connected to the rear end of the seat frame ( 21 ;  721 );    a transmission mechanism ( 4 ;  74 ) comprising a motor ( 41 ;  741 ), a telescopic rod ( 42 ;  742 ) actuated by the motor to move in a retracting direction and an extending direction, and a transmission plate ( 43 ;  743 ), the motor ( 41 ;  741 ) having an end pivotally connected to the front end of the base ( 1 ;  71 ), the transmission plate ( 43 ;  743 ) being pivotally connected to the central portion of the seat frame ( 21 ;  721 ); and    a connecting rod ( 34 ;  736 ) including a first end pivotally connected to the lower end of the backrest frame ( 31 ;  731 ) and a second end pivotally connected to the transmission plate ( 43 ;  743 );    the transmission plate ( 43 ;  743 ) including a top support portion ( 431 ;  7431 );    the telescopic rod ( 42 ;  742 ) being directed to a position below a central portion of the seat ( 2 ;  72 );    the transmission plate ( 43 ;  743 ) further including a first pivotal portion ( 432 ;  7432 ) on an upper portion of a front side thereof for pivotal connection with the central portion of the seat ( 2 ;  72 );    the transmission plate ( 43 ;  743 ) further including a second pivotal portion ( 433 ;  7433 ) on a lower portion of the front side thereof for pivotal connection with the second end of the connecting rod ( 34 ;  736 );    the transmission plate ( 43 ;  743 ) further including a third pivotal portion ( 434 ;  7434 ) on a lower portion of a rear side thereof for pivotal connection with the telescopic rod ( 42 ;  742 );    wherein when the telescopic rod ( 42 ;  742 ) is extended, the transmission plate ( 43 ;  743 ) rotates and the backrest ( 3 ;  73 ) is folded; and    wherein when the telescopic rod ( 42 ;  742 ) is retracted, the top support portion ( 431 ;  7431 ) of the transmission plate ( 43 ;  743 ) presses against the seat frame ( 21 ;  721 ) to make the rear end of the seat frame ( 21 ;  721 ) move upward and forward.    
   
   
       2 . The chair as claimed in  claim 1 , wherein the base ( 1 ) further comprises a supporting portion ( 12 ) at a rear end thereof for supporting the rear end of the seat ( 2 ).  
   
   
       3 . The chair as claimed in  claim 1 , wherein the base ( 1 ) comprises a connecting plate ( 13 ) mounted on each of two lateral sides of the front end of the base ( 1 ), the chair further comprising a connecting plate ( 24 ) mounted to each of two sides of the rear end of the seat frame ( 21 ), the chair further comprising two connecting rods ( 14 ) each having a first end pivotally connected to an associated one of the connecting plates ( 13 ) and a second end pivotally connected to an associated one of the connecting plates ( 24 ).  
   
   
       4 . The chair as claimed in  claim 1 , wherein the seat frame ( 21 ) further includes a front end to which the footrest mechanism ( 5 ) is pivotally connected, the footrest mechanism ( 5 ) comprising a toggle mechanism ( 51 ), a footrest frame ( 52 ), and a connecting rod ( 53 ), the toggle mechanism ( 51 ) including two ends respectively and pivotally connected to the front end of the seat frame ( 21 ) and the footrest frame ( 52 ), the connecting rod ( 53 ) including a first end pivotally connected to the toggle mechanism ( 51 ) and a second end pivotally connected to the second pivotal portion ( 433 ) of the transmission plate ( 43 ).  
   
   
       5 . The chair as claimed in  claim 1 , wherein the chair further comprises two armrests ( 6 ) respectively mounted on two sides of the seat frames ( 21 ).  
   
   
       6 . The chair as claimed in  claim 1 , wherein 
 the seat ( 72 ) comprises a front end pivotally connected to the front end of the base ( 71 );    the seat frame ( 71 ) comprises a front frame ( 722 ) and a rear frame ( 723 ) that is pivotally connected to the front frame ( 722 );    when the telescopic rod ( 742 ) is extended, the top abutting portion ( 7431 ) presses against the seat frame ( 721 ) to make the rear end of the seat frame ( 721 ) move upward and forward.    
   
   
       7 . The chair as claimed in  claim 6 , further comprising a second connecting rod ( 716 ) having a first end pivotally connected to the front end of the seat ( 71 ) and a second end pivotally connected to the rear frame ( 723 ) of the seat frame ( 72 ), further comprising a third connecting rod ( 737 ) having a first end pivotally connected to the backrest frame ( 731 ) and a second end, the footrest mechanism ( 75 ) comprising a toggle mechanism ( 751 ) and a footrest frame ( 752 ), the toggle mechanism ( 751 ) including two ends respectively and pivotally connected to the front end of the seat ( 71 ) and the footrest frame ( 752 ), the toggle mechanism ( 751 ) being connected to the second end of the third connecting rod ( 737 ).  
   
   
       8 . The chair as claimed in  claim 7 , further comprising an elastic element ( 753 ) having a first end connected to the toggle mechanism ( 751 ) and a second end connected to the seat ( 71 ).  
   
   
       9 . The chair as claimed in  claim 7 , wherein the second end of the third connecting rod ( 737 ) comprises an elongated slot ( 7371 ), and wherein the toggle mechanism ( 751 ) is pivotally and slidably engaged in the elongated slot ( 7371 ).