| 摘要 |
<p>638,113. Variable-pitch propellers. STONE & CO., Ltd., J., and HATCHER, E. C. Dec. 24, 1947, No. 34129. Drawings to Specification. [Class 114] [Also in Group XXXIV] In the variable-pitch propeller mechanism described in Specification 637,839, the thrust pads of the double thrust bearing are of a non-metallic bearing material such as synthetic plastic coacting with metal surfaces having a Brinell hardness of not less than 250.</p> |
