Aircraft seat with roller ball-assisted motion

Abstract

An adjustable chair is disclosed which can be used in aircraft, motor homes, or the like. In an embodiment, the chair includes a seat mounted on a base such that the weight of the seat rests on roller ball assemblies disposed on a top surface of the base. The roller ball assemblies advantageously reduce friction between the seat and the base and improve translational and rotational adjustment of the seat.

We claim:  
     
         1 . An adjustment mechanism for a chair to permit movement of the chair, the adjustment mechanism comprising: 
 a base having a top plate with an opening formed therein;    a seat structure having a bottom member with an opening formed therein;    roller buttons interposed between the bottom of the seat structure and the top of the top plate to permit movement of the seat structure relative to the base, the roller buttons each comprising a roller ball disposed within a housing such that a portion of the roller ball protrudes from an opening in the housing to contact the seat structure;    a chair post coupled to the seat structure and extending downwardly through the opening in the seat structure and the opening in the top plate, the chair post being cylindrical and having a center opening, the chair post being smaller in lateral dimension than the opening of the top plate to permit movement of the chair post in any direction;    a shaft extending through the center opening in the chair post; and    a brake supported on a lower end of the shaft to frictionally engage the top plate of the base to lock the seat structure in an adjusted position, the brake being releasable to permit adjustment of the chair.    
     
     
         2 . The adjustment mechanism of  claim 1 , wherein the roller balls comprise a low coefficient of friction material.  
     
     
         3 . The adjustment mechanism of  claim 1 , wherein the brake comprises: 
 a lower brake plate; and    an upper brake plate disposed between the lower brake plate and the top plate, the upper brake plate having a central opening which is smaller than an outer dimension of the lower brake plate such that the upper brake plate overlaps the lower brake plate, the upper brake plate having an outer dimension which is greater than the opening in the top plate.    
     
     
         4 . The adjustment mechanism of  claim 3 , wherein the upper brake plate has a rectangular shape.  
     
     
         5 . The adjustment mechanism of  claim 3 , wherein the top plate comprises: 
 a plurality of runners.    
     
     
         6 . The adjustment mechanism of  claim 5 , wherein the upper brake plate is coupled to a lower surface of the top plate by the runners to prevent rotation of the upper brake plate.  
     
     
         7 . The adjustment mechanism of  claim 1 , further comprising: 
 a cam coupled to the chair post; and    a cam follower coupled to the shaft and positioned relative to the cam such that rotational movement of the shaft results in axial movement of the shaft.    
     
     
         8 . The adjustment mechanism of  claim 7 , wherein the cam comprises: 
 an upper cam surface, the cam and the cam follower positioned such that the cam follower rides along the upper cam surface as the shaft is rotated.    
     
     
         9 . The adjustment mechanism of  claim 8 , wherein the cam follower comprises: 
 a pair of bearings mounted on opposite sides of the shaft.    
     
     
         10 . The adjustment mechanism of  claim 8 , wherein the upper cam surface comprises: 
 sloped sections; and    sections with zero slope.    
     
     
         11 . The adjustment mechanism of  claim 7 , further comprises: 
 a lever extending radially from the shaft;    a cable attached to the lever; and    a cable actuating mechanism connected to the cable to cause rotation of the shaft in a first direction.    
     
     
         12 . The adjustment mechanism of  claim 11 , further comprising: 
 means for normally biasing the shaft in a second direction of rotation opposite to the first direction of rotation.    
     
     
         13 . The adjustment mechanism of  claim 12 , wherein the means for normally biasing the shaft comprises: 
 an elastically deformable member having a first end and a second end, the first end coupled to the lever and the second end coupled to a bracket which is coupled to the seat structure.    
     
     
         14 . The adjustment mechanism of  claim 3 , wherein the lower brake plate has an outer dimension which is smaller than the opening in the top plate member.  
     
     
         15 . An adjustment mechanism for a chair to permit movement of the chair, the adjustment mechanism comprising: 
 a base having a top plate with an opening formed therein;    a seat structure having a bottom member with an opening formed therein;    roller buttons interposed between the bottom of the seat structure and the top of the top plate to permit movement of the seat structure relative to the base, the roller buttons each comprising a roller ball disposed within a housing such that a portion of the roller ball protrudes from an opening in the housing to contact the seat structure;    a chair post coupled to the seat structure and extending downwardly through the opening in the seat structure and the opening in the top plate, the chair post being cylindrical and having a center opening, the chair post being smaller in lateral dimension than the opening of the top plate to permit movement of the chair post in any direction;    a shaft extending through the center opening in the chair post; and    a brake supported on a lower end of the shaft to frictionally engage the top plate of the base to lock the seat structure in an adjusted position, the brake being releasable to permit adjustment of the chair, the brake comprising 
 a lower brake plate, and  
 a rectangular upper brake plate coupled by runners to a lower surface of the top plate and disposed between the lower brake plate and the top plate, the upper brake plate having a central opening which is smaller than an outer dimension of the lower brake plate such that the upper brake plate overlaps the lower brake plate, the upper brake plate having an outer dimension which is greater than the opening in the top plate.