Patent ID: 7066819
Filing Date: 2006-06-27
Classification: F16D,Y10T

Abstract:
1. A coupling device comprising: a driving member and a driven member, the driven member including a threaded member having a first thread, a threaded portion on the driving member having a second thread corresponding to the first thread formed on the threaded member of the driven member; a planar thrust contact portion provided between the driving member and the threaded portion, the planar thrust contact portion being formed so as to remain stationary with respect to an axial direction when the threaded portion is tightened onto the threaded member of the driven member; and a breakable portion provided between a part of the threaded portion and the planar thrust contact portion having a tensile strength that breaks at a predetermined level of the thrust force, wherein the first and second threads are formed in a direction to generate a thrust force on the breakable portion when one of the first and second threads are rotated with respect to the other of the first and second threads in the same direction as a direction of a torque transmitted from the driving member to the driven member; and the threaded portion and the breakable portion are provided in a cylindrical portion, the breakable portion being thinner in a radial direction than the threaded portion.