| 摘要 |
<p>The base for a slewing treatment chair, partic. as used in dentistry, has a disc rotating on a first bearing in a cylindrical recess in a baseplate, and a retaining washer fixed to the baseplate and pressing via a second bearing against the top of the disc. The washer encloses the disc and fits over an annular shoulder on the outside of it. The plain bearing comprises flat strips of bearing material. The strips can be divided into a number of sections, spaced ar regular angles. The bearing material can incorporate polytetrafluoroetbylene and lead in porous bronze.</p> |
