| 摘要 |
<p>The cord pulley block strap is formed by cutting a length of cord to form a strap of a given circumference (C). A section of the cord, for the central core, is taken at each end of a length which is one half C. The cord thickness is modified, at the centre and end sections, to give one dia. (D1) at the ends and a second dia. (D2) at the centre. the cord is twisted six times round a former with the first dia. (D1) to form a hawser. The former is withdrawn, and the ends are inserted into the opening to form the core.</p> |
