Abstract: In a tape cassette including a brake member and a wire-shaped brake spring supported at its opposite ends by the brake member, the brake member is biased by the brake spring to come into pressure contact with hubs and thereby lock the hubs. One end of the brake spring is completely fixed to the brake member, and the other end of the brake spring is supported by the brake member with a degree of freedom parallel to the axial direction of the brake spring. The brake member has a guide recess opened at one end thereof and is adapted to be slidably moved to effect hub locking and unlocking operations while being guided by a guide pin formed in a cassette case, the guide pin being inserted through the guide recess. The opened end of the guide recess diverges to form a tapering portion so that the guide pin may be smoothly introduced into the guide recess upon sliding movement of the brake member.

Abstract: A method of measuring an unbalance value of a wheel wherein a plurality of curves showing the relation between the magnitude of vibration of the wheel when it is rotated and the true value of the unbalance which are preliminarily obtained according to the kinds of wheel or automobile on which the wheel is mounted are memorized and compared with the magnitude of the vibration of the wheel to be tested while it is rotated. A rough value of the unbalance corresponding to the magnitude of the vibration of the wheel to be tested is obtained by using a curve M which shows the largest change of the magnitude of the vibration with respect to the true value of the unbalance. The measuring of an unbalance value is repeated with respect to the wheel on which a counter-weight corresponding to the rough value of the unbalance is attached.