Belt type mate to follow a cam/ offset sprocket help

What I'm trying to do is have a belt/ chain wrap 360 degrees or less around a egg shape or offset hole cam and when pulled in a linear direction from the end of the belt/ chain it will straighten out, such a connecting it to a hydraulic cylinder.

I can get it to work with a cam that has a single radius only.


Thanks for any help  P.S. I'm using SW08 

Updated with model:

When the violet shaft is moved down i would like the green sprocket/ cam to spin, i just cant figure out what mates that will allow he chain to follow the sprocket on a tangent but also be parallel to the violet shaft.

I need this to do a cosmosxpress study on the hydraulic cylinder

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