| 摘要 |
<p>Charging apparatus comprises a housing which has at least one bladed fan, an air inlet opening, and a filter 16 which is arranged at the air inlet opening and has a plurality of openings 17 which are at least half as large as the minimum spacing Smin of the fan blades 22. The ratio of the diagonal cross-section Omax of each filter opening 17 to the blade spacing Smin may be between 0.5 and 1.5, and may further be between 1 and 1.3. The filter 16 may be grid shaped, of unitary construction, and formed integrally with at least part of the housing. The filter 16 may also be coated to have a self-cleaning effect. The charging apparatus may be for a battery of an electric hand tool.</p> |
