Abstract: Stationary wave vibrations in a rotation coupling device comprising a rotating shaft disposed within a tubular sheath are suppressed by providing the sheath at the crests of the stationary wave with inwardly projecting vibration suppressing device, such as tubular sheath joints with inward protrusions or vibration suppressing rings disposed inside the sheath, which reduce the inner diameter of the sheath at the wave crests compared to the inner diameter of the rest of the sheath.

Abstract: A connection for a flexible cable and a speedometer. It comprises a connector engagable with a stem section of the speedometer and mounted on an end of the flexible cable, the flexible cable consisting of an outer tube and an inner tube, a rectangular elongate member having a conical tip and provided to the end of the inner shaft, a hollow rotatable shaft disposed in the stem section of the speedometer, said rotatable shaft being formed with a rectangular bore section in which the rectangular elongate member is engagable and stepped portions which are located in an inlet of said rectangular bore section and each provided with an inclined surface for guiding the elongate member.