The double pendulum consists of link 3, turning about fixed axis A, and link 5 which is connected by turning pair B to link 3. Two identical pulleys 1 and 6 rotate about axes A and B. Two identical pulleys 2 and 4 rotate about axes C and B. Pulleys 6 and 4 are rigidly attached together. Two endless flexible links 7 and 8 run over pulleys 1 and 6, and 4 and 2. When pulley 1 rotates about axis A, all the other pulleys rotate, and axis C can be moved to any point in the plane of the drawing within a radius of R=A͞B+B͞C.
$3574$CFL,DF$