Patent ID: 7678022

Claim:
A loading device of a leg extension machine, comprising: a base frame; a base body, disposed on the base frame, and having a seat cushion and a backrest cushion; left and right leg extension elements, disposed symmetrically at opposite positions between the base frame and the base body, and each leg extension element including an axle pivotally coupled between the base frame and the bottom of the base body, a first rod provided for resting a foot, and a second rod disposed on an inner side of the middle of the first rod for attaching a thigh, and extended from the bottom to the top, and having a pad installed thereon; characterized in that: the two axles of the left and right leg extension elements include a set of symmetric left and right gear disks linked and engaged with each other, such that when the leg extension elements are spread apart or pressed towards each other, the two axles drive the left and right gear disks to rotate in opposite directions synchronously; a motor, installed on the base frame, and having a first gear installed onto a main shaft of the motor and engaged with one of the left and right gear disks, for the left and right gear disks to produce a driving resistance synchronously; a current controller, including a DC power supply, a current and direction switching control unit, a signal processing interface, and a positive and negative rotation signal decoder, such that an exerciser can control the torque of the motor or change the rotating direction of the motor to switch inner thigh and outer thigh exercises and replace a traditional manual mechanism by adjusting a current inputted to the motor from a microcomputer control panel according to a linear relation and a direct proportion between the torque of the motor and the current; and a movement path sensor comprising an optical interrupt disk installed on and linked to the axle, and an optical coupler installed at the periphery of the optical interrupt disk, such that when the axle drives the optical interrupt disk to transmit a pulse signal generated by the optical coupler to the positive and negative rotation signal decoder in the current controller, positive and negative rotation signals are transmitted to the microcomputer control panel for controlling a curved load and compensate a load current appropriately.