| 摘要 |
<p>1,210,135. Surface aerator. JOHNSON CONSTRUCTION CO. A.B. 17 Oct., 1968 '[19 Oct., 1967], No. 49267/68. Heading B1C. A surface aerator comprises a frusto-conical body 5 covered by a plate and provided with a base plate 3 and blades 7 which extend radially outwards to a point short of the periphery of plate 4. Although the blades essentially lie in radial, planes they may be slightly curved, Fig. 2 (not shown).</p> |
