Need a simple design for Piston(spring?)/Crankshaft

[swightness]

I am looking for a piston/crankshaft design that the crank would only rotate during the power stroke, and the piston can return to the initial position without any rotation of the crank. The piston is manualy operated, so there is no worry about momentum at the bottom of the cycle. Any thoughts?

Thank you,

JH

 

[swightness]

Need a piston/crank design where Crank only turns on power stroke

I need design ideas for a piston (that is operated by a human using a push/pull mechanism) that rotates a crank only on the power stroke (where the piston is moving towards the crank) Because it is manually operated, is it possible to have some sort of crank design where it operates just like a normal 2-stroke engine on the power stroke, and once the piston is at the low point (and the entire system is in rest), there is some mechanism that allows the crank to "slide" in the same direction as the piston while the piston is being pulled away from the crank shaft? Any other design idea that would allow the crank to only turn as the piston is moving towards the crank shafe would help. Thank you

 

[berkeman]

(Two threads merged -- please do not multiple post)

Can you just use a ratched mechanism between the crankshaft and the manually operated crank?