| 摘要 |
A dumbbell having adjustable inertial resistance load in the field of athletic sports devices is disclosed. The structure of the present invention is characterized in that the hand grip of the dumbbell is provided inside with a rotatable main shaft, the two swing hammer rods and the swing hammers at both ends of the main shaft constitute a normal pendulum, and the two pendulums at both ends of the main shaft are connected through the main shaft, so as to be functionally combined into the function of one eccentric pendulum. The main shaft, the two swing hammer shafts and the swing hammers constitute an eccentric pendulum. The two pendulums fixed at both ends of the main shaft may be adjusted at different angles. In case the angle between the two pendulums is zero degree, upon the rotation of the pendulums, the forces between the hand grip and the hand, besides the mutual force in the up-and-down direction, also include the periodic inertial force in the fore-and-aft direction. In case the angle between the two pendulums is non-zero degree, upon the rotation of the pendulums, the forces also include the periodic inertial force in the left-and-right direction. By adjusting the weight of the swing hammer, the distance from the swing hammer to the main shaft and the included angle of the two swing hammer rods, the amplitude of the inertial force may be adjusted. This inertial force is a resistance load, and functionally speaking, the dumbbell of the present invention has the characteristic of adjustable inertial resistance load. |
