| 摘要 |
<p>A fastener comprises a pair of members which are pivotable w.r.t. one another from an inner to an outer position, and biasing to urge the members apart. The biasing is pref. a rubber or neoprene block, and there is an abutment against which the members can bear in order to pivot. The abutment pref. has rounded recesses within which rounded ends of the members can pivot, and the members have weakened regions so as to break when struck at right angles to facilitate removal of the key from tooth and adapter. Each member pref. has an arm extending from a rounded inner end, the arm having a triangular enlargement with a forwardly inclined part and the weakness provided between the rounded end and arm.</p> |
