Input: blue bar linearly reciprocating with constant stroke length.
Output: grey bar linearly reciprocating with adjustable stroke length.
Yellow slider has revolution joint with pink slider.
Adjust position of the pink slider on the fixed runway to get various stroke lengths of the output.
Lo = Li.(a+x)/x
Li: input stroke length
Lo: output stroke length
a: distance between sliding lines of blue bar and grey bar.
x: distance from pivot center of the pink slider to sliding line of the blue bar.
The adjustment can be performed when the mechanism is running.