| 摘要 |
<p>A jig for boring large diameter holes in pipe ducts, on in round containers, has a steel support frame on two pairs of angled slider blocks to sit on the rounded duct. A magnetic grip, secured by screws, holds the drilling system, while the whole jig is additionally secured by a strap. The large diameter holes are bored by circular cutting heads, with cooling for the drilling operation. The drill shaft is located in a brass sleeve which also has lubricating ducts.</p> |
