| 摘要 |
Abstract of US 4308489 (A) A method and apparatus for maintaining predetermined speed ratios between at least two motions are described. The speeds of the motive power sources for the motions are controlled by signals having values proportional to the ratio of those speeds, and in the alternative, if lower in value, reference signal which may be generated by an operator. The invention is described in connection with its application in a power shovel where it controls the ratio of crowd speed to hoist speed. |
