| 摘要 |
550,103. Lightning arresters. NORTON GRINDING WHEEL CO., Ltd. June 13, 1941, No. 7519. Convention date, June 13, 1940. Drawings to Specification. [Class 38 (iv)] [Also in Group XXXVI] The valve or resistance material for lightning arresters having series gaps includes boron carbide in granular form preferably together with the usual silicon carbide. In the preferred form grains of silicon carbide of 60 mesh are mixed with sodium silicate solution which forms a coating to which fine grains of boron silicate of say 200 mesh are caused to adhere. The material is a better conductor than silicon carbide and has a better shut-off characteristic. The arrester in which the material is used is smilar to that described in Specification 542,520. |
