Hi, I'm a university second year Mechanical Engineering student and I'm new to this module of Kinematics and Dynamics of Machinery and I've just learned the concept of the Grashof Criterion where "(adsbygoogle = window.adsbygoogle || []).push({}); The sum of the shortest and longest link of a planar four-bar linkage cannot be greater than the sum of remaining two links if there is to be continuous relative motion between the links."

L[itex]_{max}[/itex]+L[itex]_{min}[/itex][itex]\leq[/itex]L[itex]_{a}[/itex]+L[itex]_{b}[/itex]

Can anyone explain to me why is it so? Why must the sum of the max and min linkages be longer than the other 2?? Is there a mathematical equation to prove this? Thanks for the assistance :)

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# Can anyone explain the Grashof Criterion ?

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