Descent rescue device with double brake and back and forth controlled

A descent rescue device with a double brake with back and forth control comprising an outer shell and a tyra mechanism, a wedge wheel, a double braking mechanism and a line-guiding mechanism disposed inside the outer shell, wherein the tyra mechanism comprises an energy conversion adjusting screw having an elastic buffer disposed thereon, the double braking mechanism comprises an outer braking component, an inner braking component and a locking mechanism, wherein the inner braking component is operatively associated with the energy conversion adjusting screw of the tyra mechanism, the wedge wheel is disposed between the inner braking component and the outer braking component, a bundle of steel wire rope is wrapped around the wedge wheel, the locking mechanism abuts against the outer braking component and the outer shell;

• wherein during rescue operation, when no force or a force beyond a maximum threshold acts on the outer braking component, the wedge wheel is locked by the outer braking component and the inner braking component;
• when a force lower than the maximum threshold acts on the outer braking component, the energy conversion adjusting screw of the tyra mechanism triggers the inner braking component to provide a certain damping force such that the wedge wheel is unlocked and the steel wire rope exits the outer shell guided by the line-guiding mechanism;
• the inner braking component comprises a main axis, a first braking block, a braking hub, a second braking block, a block linkage arm and a block closing rotation roller, wherein the first braking block is disposed on the main axis, and operatively connected with the energy conversion adjusting screw of the tyra mechanism via the block linkage arm and the block closing rotation roller, the brake hub is disposed between friction blocks and the second braking block and fixed with the wedge wheel, and during the rescue operation, when the tyra mechanism is pulled out of the outer shell by the gravity of a target being rescued, the energy conversion adjusting screw of the tyra mechanism then pulls the block linkage arm to rotate together with the block closing rotation roller, then the rotating block closing rotation roller pushes the first braking block against the brake hub and the second braking block to provide the damping force.