First inversion of Four Bar Chain
Coupled wheel of locomotive (Double crank Mechanism):
The mechanism of a coupling rod of a locomotive (also known asdouble crank mechanism) which consists of four links, is shown in Fig.
In this mechanism, the links AD and BC (having equal length) act as cranks and are connected to the respective wheels.
The link CD acts as a coupling rod and the link AB is fixed in order to maintain a constant centre to centre distance between them.
This mechanism is meant for transmitting rotary motion from one wheel to the other wheel.
