| 摘要 |
<p>The internal bearing surface is such as a ball joint, is fitted with a knitted covering which consists of threads of two materials. One, forming the side facing the surface is cotton or pref. glass fibre and is glued to the surface. The second, facing the second half of the joint, has a low coefficient of fricition, pref. polytetrafluoroethylene. Covering is knitted in the same manner as the heel of a sock, to provide the shape required for the bearing.</p> |
