Hub for a rotatable chair

Abstract

According to an example aspect of the present invention, there is provided a hub for a rotatable chair, comprising a swivel shaft, a swivel shell arranged rotatably around the swivel shaft and a locking piston placed axially movably within the swivel shaft. There is a hole in the swivel shaft and a ball is placed movably in the hole. The ball is movable to a pocket in the swivel shell and an actuating mechanism is arranged for moving the locking piston in longitudinal direction of the swivel shaft for pushing the ball to the pocket and releasing it therefrom through the hole.

1 . A hub for a rotatable chair, comprising:
 a swivel shaft;   a swivel shell arranged rotatably around the swivel shaft;   a locking piston placed axially movably within the swivel shaft;   a hole in the swivel shaft;   a ball placed movably in the hole;   a pocket in the swivel shell; and   an actuating mechanism for moving the locking piston in a longitudinal direction of the swivel shaft for pushing the ball to the pocket and releasing it therefrom through the hole.   
     
     
         2 . The hub according to  claim 1 , wherein the hub comprises a plurality of the holes, balls, and pockets, and wherein the number of the holes and the balls is greater than one and the number of the pockets is a multiple of the number of balls. 
     
     
         3 . The hub according to  claim 1 , wherein the hub comprises a plurality of the holes and a plurality of the pockets, and wherein the angle between the holes is dividable with the number of pockets. 
     
     
         4 . The hub according to  claim 1 , wherein the hub comprises a plurality of the pockets, and wherein the pockets are disposed in a star pattern. 
     
     
         5 . The hub according to  claim 1 , wherein the actuating mechanism comprises an activating pin and a spring. 
     
     
         6 . The hub according to  claim 5 , wherein the spring is one of the group: coil spring, gas spring, elastic cushion spring, leaf spring or magnetic spring. 
     
     
         7 . The hub according to  claim 1 , wherein the hub comprises a plurality of the balls, holes, and pockets, and wherein the number of the balls and the holes is four and the angle between the pockets is 45°.