Patent ID: 7226398

Claim:
An apparatus for practicing the art of attack and defense comprising: a base comprising a base bottom and a casing, the casing having a recess with a first hook member; an elastic force regulating set being disposed on the base, providing a hollow cylinder, a Y-shaped hollow post and an elastic device, the elastic device having two ends, the hollow cylinder having outer screw threads engaging with inner screw threads arranged in the Y-shaped hollow post; and a cylindrical member being disposed on the Y-shaped hollow post having a second hook member at the bottom thereof for being joined to the elastic device; wherein the hollow cylinder engages with the Y-shaped hollow post before being inserted into the recess of the base and one end of the elastic device is joined to the first hook member and the other end of the elastic device is joined to the second hook member respectively such that one of the ends joining with the second hook member is located at an upper recess part of the Y-shaped hollow post and a total length including the Y-shaped hollow post and the hollow cylinder is adjusted by way of regulating engagement of the outer screw threads of the hollow cylinder with the inner screw threads of the Y-shaped hollow post to change the restoration force of the elastic device.