| 摘要 |
<p>A chuck for gripping round bars or tubes consists of an outer tube (10) which houses a number of rings (30, 40). The rings have spherical outer surfaces and pivot inside the tube on two diametrically opposite bolts (34). These rings also have two diametrically opposite tongues (32) aligned at right angles to the bolts and projecting in axially opposite directions. The rings (40) have cylindrical outer surfaces with a single tongue (42) and are attached by screws through slots in the wall of the tube to a rod. The rod is moved axially by a pair of nuts screwed on the end of the tube. This axial movement of the rod brings each cylindrical ring closer to its neighbouring spherical ring, causing it to rotate about the pivot so that the tongues grip the internal bar.</p> |
