Hula chair having aligned movement with curvilinear-circular, swivel-rock, and vertical motions

摘要

The hula chair includes an upper base (23) and an intermediate base (21). The bases (21 and 23) are linked together by the specially designed oversized universal joint which is combined by two components: the ring (16) and the plate/spacer (17). The plate/spacer (17) is connected to the upper base (23). The ring (16) is connected to the intermediate base (21) by the stud (19). The upper base (23), can swivel-rock individually from the intermediate base (21), because of a universal joint (16, 17, 19). Two sets of three cams (10a, 10b, 10c and 20a, 20b, 20c) are placed under the plate-spacer (17) and on the intermediate base (21). A block (6), which is positioned at the center of the intermediate base (21), can slide inside a slot (7). The crankshaft (9) goes through the block (6) and the intermediate base (21 ). Three arms (11a, 11b, 11c), can vertically slide on the top end of the crankshaft (9). Three rollers (12a, 12b, 12c), which are placed on the top support of the arms (13a, 13b, 13c), can roll on the surface of their relative cams (10a, 10b, 10c). The rollers (15a, 15b, 15c), which are placed on the bottom support of the arms (14a, 14b, 14c), can roll on the surface of their relative cams (20a, 20b, 20c). A cam (4) is built on the base stand (22), just beneath the slotted block (2). A slide (3) can slide inside the slot formed in slotted block (2). A roller (5) that is connected to one end of the slide (3) runs in or between the groove (4g) of the cam (4). The crankshaft (9) is fixed to the other end of the slide (3) opposite to the end having the roller (5).