Linear motion transmission and amplification linkage - has two arms of equal length and asymmetrically mounted jack

摘要

The linkage consists of two arms of equal length (a) with a common pin joint (K). One of the arms has its other end mounted on a fixed pivot (V1). The other arm is fastened to the slide (S) by the pivot (G). A jack (A) is mounted at one end on a pivot (V2) and it is fastened to one of the arms (a) by a pivot (P). It is proved mathematically that provided the lengths (e) and (f) are adjusted so that (e) equals twice the square root of the product of (e) and (f) then there is a constant ratio between the travel of the slide (S) and the travel of the jack. This ratio can be of the order of 10:1 so that a relatively short stroke jack (A) can be used to produce a large travel of the slide (S).