Question

Which of the following statements is incorrect

(a) Grashof’s rule states that for a planar crank-rocker four bar mechanism, the sum of the shortest and longest link lengths cannot be less than the sum of the remaining two link lengths.

(b) Inversions of a mechanism are created by fixing different links one at a time.

(c) Geneva mechanism is an intermittent motion device.

(d) Gruebler’s criterion assumes mobality of a planar mechanism to be one.

This question was addressed to me by my college professor while I was bunking the class.

I'm obligated to ask this question of Inversion of Mechanism in division Simple Mechanisms of Machine Kinematics

Answer 1

Right answer is (a) Grashof’s rule states that for a planar crank-rocker four bar mechanism, the sum of the shortest and longest link lengths cannot be less than the sum of the remaining two link lengths.

To explain: According to Grashof’s rule for complete relative rotation r/w links L + S < p + q.