| 摘要 |
575,952. Self-cleaning weather screens. HELPS, C. E. March 7, 1944, No. 4166. [Class 20 (iii)] A self-cleaning screen giving a view of 360 degrees in azimuth and at least 180 degrees in a vertical plane consists of a transparent dome rotated about its axis in order to throw off moisture by centrifugal action. The dome may be of glass or of the material known under the Registered Trade Mark "Perspex," and it may be driven at the rim or lower part of the sides by a gear or friction drive from a motor. |
