| 摘要 |
<p>The cramp-iron or rivet is of wire, comprises two legs joined together by an intermediate portion. The legs have near their outer ends uneven surfaces (3) in the form of grooves, barbs or notches etc. which can extend round the periphery of the legs. They can be shaped so as to produce a sawtooth section, the teeth tapering gradually towards the free end while on the other side they are nearly at right angles to the axis of the leg.</p> |
