| 摘要 |
A mechanical linkage has an input lever pivoted on a carrier and coupled to a first link. Three additional links are pivotally interconnected with the first link to form a rhombus. A pivot point on the rhombus, which is opposite the pivotal mounting of the first lever, is constrained to move through an arc whose radius is equal to the lengths of each of the links forming the rhombus. The position of the centre of this arc is adjustable by a second lever. One of the links forming the rhombus is coupled to an output lever, whose position is thereby dependent on the positions of the input levers. There is a position of the first lever where the second lever is ineffective to move the output lever. The first lever can be locked in this position and the carrier moved pivotally on a support. |
