Abstract: Disclosed is an elasticity-controllable trampoline using a plate spring that can be manufactured in small size and in low height compared with existing trampolines using coil springs, thereby proving stability to a user. Also, it has a mechanical structure, thereby providing a semi-permanent life term. Under the principles of a lever using the third law of motion, particularly, the plate spring carries out action in smooth manner, in operation and also carries out reaction with the jumping operation of the user, such that the trampoline of the present invention will have a strong elasticity. In addition, a plate spring support movable stand on the plate spring is moved in simple manner according to the principles of the lever, thereby allowing the elasticity of the plate spring to be controlled. With the adjustment of the upward and downward motion of an action point operation bolt, the height of the upward and downward motion can be adjusted.

Abstract: A gymnastic apparatus for performing vaults possesses a lower portion, an upper part arranged on same in a vertically adjustable fashion and constituted by a board arranged in a resilient manner on the lower portion. A gymnast running toward a front side of the apparatus, places his hands on the top side of the board, which forms a support face, applies his weight for an instant and leaps over the apparatus. In such leap he is aided by the resilient board. A front region of the board rises from the front convexly toward the rear in a arcuate manner, the arcuate region merging with an approximately horizontal flat region. The transitional region and/or the flat region serves a support face.