Massage chair

Abstract

A massage chair includes: a base unit; a rocker mechanism including an actuator that is coupled to the base unit, at least one output bar that is connected pivotally to the base unit, an input bar that is connected to and that is driven rotatably by the actuator, and a connecting bar that is connected pivotally to the input bar and the output bar; and a seat unit connected immovably to the output bar. The input bar, the output bar, the connecting bar, and the base unit cooperate to constitute a crank-rocker planar four-bar linkage. The actuator actuates rotation of the input bar, which in turn drives reciprocating swing motion of the output bar and the seat unit.

What is claimed is: 
     
         1 . A massage chair comprising:
 a base unit;   a rocker mechanism including
 an actuator that is coupled to said base unit, 
 at least one output bar that is connected pivotally to said base unit, 
 an input bar that is connected to and that is driven rotatably by said actuator, and 
 a connecting bar that has opposite ends connected pivotally and respectively to said input bar and said output bar, and that cooperates with said input bar, said output bar, and said base unit to constitute a crank-rocker planar four-bar linkage; and 
   a seat unit connected immovably to said output bar;   wherein said actuator actuates rotation of said input bar, which in turn drives reciprocating swing motion of said output bar and said seat unit.   
     
     
         2 . The massage chair as claimed in  claim 1 , wherein said rocker mechanism includes a pair of said output bars, and further includes a frame member bridging and connecting immovably said output bars. 
     
     
         3 . The massage chair as claimed in  claim 2 , wherein said seat unit includes a seat member fixed to said frame member of said rocker mechanism, and a backrest member connected to said seat member. 
     
     
         4 . The massage chair as claimed in  claim 3 , wherein said rocker mechanism further includes a pair of reinforcing links, each of which is connected between said frame member and a respective one of said output bars. 
     
     
         5 . The massage chair as claimed in  claim 4 , wherein said base unit includes a plurality of spaced-apart foot members, and a bracket bridging said foot members, said actuator being connected to said bracket. 
     
     
         6 . The massage chair as claimed in  claim 5 , wherein said bracket of said base unit has an oblong slot, and a fastener extending through said oblong slot and fastening said actuator to said bracket, said actuator being adjustable in position when said fastener is unfastened and moved along said oblong slot. 
     
     
         7 . The massage chair as claimed in  claim 1 , wherein said actuator is a driving motor. 
     
     
         8 . The massage chair as claimed in  claim 1 , wherein said actuator has an actuator shaft extending substantially horizontally and connected to said input bar, and said rocker mechanism further includes a pivot shaft that is mounted to said base unit substantially horizontally, that is lower than said actuator shaft, and that extends through a lower end of said output shaft to connect pivotally said lower end to said base unit. 
     
     
         9 . The massage chair as claimed in  claim 8 , wherein said input bar has one end connected to said actuator shaft, said connecting bar having one end connected pivotally to another end of said input bar and having the other end connected pivotally to an upper portion of said output bar, said seat unit being connected immovably to said upper portion of said output bar and being disposed above said connecting bar. 
     
     
         10 . The massage chair as claimed in  claim 9 , wherein said actuator shaft is disposed more forward than said pivot shaft so that an imaginary surface interconnecting said actuator shaft and said pivot shaft inclines forward with respect to a vertical surface passing through said pivot shaft. 
     
     
         11 . The massage chair as claimed in  claim 10 , wherein said output bar, when being tilted forward, forms a greatest forward tilted angle with respect to the vertical surface passing through said pivot shaft, and said output bar, when being tilted rearward, forms a greatest rearward tilted angle with respect to the vertical surface passing through said pivot shaft, the rearward tilted angle being larger than the forward tilted angle. 
     
     
         12 . The massage chair as claimed in  claim 9 , wherein said rocker mechanism includes a pair of said output bars, and further includes a frame member bridging said upper portions of said output bars and fixed below said seat unit, and a pair of spaced-apart reinforcing links, each of said reinforcing links having a bottom end connected immovably to said lower end of a respective one of said output bars, and a top end connected immovably to said frame member and spaced apart from said upper portions of said output bars. 
     
     
         13 . The massage chair as claimed in  claim 9 , wherein said base unit includes a plurality of spaced-apart foot members, and a bracket bridging said foot members and extending upwardly, said pivot shaft and said actuator being mounted to said bracket.