Patent ID: 7044558

Claim:
A ball chair with a retaining device comprising: a seat ( 10 ) having a seat frame with a top face ( 11 ), a bottom face, a front edge, and a rear edge, multiple legs ( 12 ) attached to the bottom face of the seat frame to support the seat frame; and a passage ( 15 ) defined in the top face ( 11 ) of the seat frame; a spherical cushion ( 20 ) being a resilient bladder, having a diameter and partially received inside the passage ( 15 ) to rest on the seat; and two retaining devices mounted respectively on and extending up from the front edge and the rear edge of the seat frame to hold the spherical cushion ( 20 ) on the seat frame, wherein the two retaining devices are retaining rods ( 30 , 40 ), each retaining rod ( 30 , 40 ) is curved to correspond to the spherical cushion ( 20 ).