| 摘要 |
<p>The control valve mechanism of, for example a hydraulic motor for a chain saw, includes a two-position spool having a hollow interior permanently connected to reservoir and a cylindrical wall formed with ports which are closed in one valve position and open in the other valve position. During movement of the spool into the motor-operating position, a lubricant passageway is opened before the motor is fully operational.</p> |
