| 摘要 |
987,078. Earth-moving equipment. CATERPILLAR TRACTOR CO. Nov. 4, 1963 [Dec. 26, 1962], No. 43395/63. Heading E1F. Positioned in a fluid passage to normally prevent flow through the passage between the head and rod ends of the or each jack 16 for raising and lowering the bowl of an earthmoving, bowl type scraper is a quick drop valve 86 allowing of rapid venting of the piston end of the cylinder when the bowl is lowered and in series with this valve is a check valve 65 for preventing accidental dropping of the bowl if the hydraulic fluid supply pipes to the jack are damaged. Specification 959,872 is referred to. |
