초록
The return spring which is one of main elements in a dobby system is often fractured during working. The failure mechanism is investigated experimentally and analytically, and the type of failure is proved as fatigue fracture by repeated loads. The fracture angle of the spring is in good agreement with the result obtained by theoretical analysis. The closed form solution related to the deflection and maximum stress is also derived, which can be applied directly to the design of the return spring.