PURPOSE: To operate surely a regulator control lever with simple constitution by engaging the movement of the lever following a cam of a loading ring to a tension regulator via an indirect lever.
CONSTITUTION: The tension regulator operating mechanism consists of a rotating roller 2a, a guide lever 2 with spring having a guide hole 2b, an indirect lever 3 and a tension regulator lever 4. The indirect lever 3 fixes the regulator lever 4 at the stop of the loading ring 1. At the end of loading, the rotating roller 2a is put into a recessed part of the ring 1, the indirect lever 3 is moved together with the regulator lever 4 and the lever 4 is made free. Thus, the lever is interlocked directly to the loading ring 1 with simple constitution so as to attain sure operation.