Novel tumble pulley

The invention provides a novel tumble pulley which comprises a pothook, a flying ring which is arranged at the upper end of the pothook, a fixed pulley which is arranged at the lower end of the pothook and a blocking device, wherein the blocking device comprises an arc-shaped self-locking rod, a supporting rod is fixedly arranged on the inner wall on the opening side of the pothook, and the middle part of the self-locking rod is hinged to the supporting rod; in an initial state, the self-locking rod is suspended under the effect of gravity of the self-locking rod, a gap is reserved between the upper end of the self-locking rod and the inner side of the pothook, and the lower end of the self-locking rod and the pothook form a cable inlet; in a locked state, the upper end of the self-locking rod is subjected to the pressure of the cable and moves upward to be connected with the inner side of the pothook in a leaning manner, and the lower end of the self-locking rod upwarps upward, so that the cable inlet pitch is reduced. The novel tumble pulley provided by the invention has the advantages of being scientific in design, convenient to lock, high in safety and simple in structure.