| 摘要 |
<p>A dust suction system for a power hand tool has a dust collecting cowl positioned near the working tool and with a suction chamber to collect the grit and dust. The suction chamber is fitted with an impeller (13) to provide the suction effect. The inlet duct (17) is arranged tangential to a cylindrical chamber (22) to provide a cyclonic action to remove grit and particles from the airstream before being drawn through the filter (19). In this way the maintenance periods between filter changes is extended and the filter is not prematurely blocked by large debris. The inside walls of the collecting chamber are rounded to enhance the cyclonic effect.</p> |
