Five-Bar Grashof Criteria

Abstract

In this paper, the five-bar Grashof criterion is proposed and proved. A five-bar linkage is a Class I linkage if lmax + lmin 1 + lmin 1 ≤ m + n is satisfied, otherwise it is a Class II linkage. Depending on the location of the two input links, a Class I linkage may be classified as (1) a triple-crank or a double-crank linkage if its two shortest links are either the input or fixed links; (2) a conditional double-crank or single-crank linkage if its shortest link is the fixed or an input link and the next shortest link is neither the fixed nor an input link; (3) a zero-crank linkage if none of the foregoing conditions is satisfied. A Class II linkage is neither a triple-crank nor a double-crank linkage. However, it may be a conditional double-crank, single-crank or zero-crank linkage. The proposed five-bar mobility criterion includes the four-bar Grashof criterion as a special case.