Underactuated Linkage Design

[CJne]

Hi! I am interested in building a kinematic model of an underactuated gripper. I would like to use this patent: https://patentimages.storage.googleapis.com/dd/0e/60/31f32bb3d87654/WO2013075245A1.pdf but change the actuation to a pneumatic piston, how would I modify the design so I can use it with the piston that can only be fully extended or retracted?

 

[rb1957]

WTLDR ! but fig 5A seems to give ideas ... of powering the common drive shaft (#550) by an actuator on a lever arm ... though this limits the travel to about 1/2 a rotation of the shaft so this'll change the gearing.

Now whether this allows you to get around their patent is a whole different matter. Though I don't know if you can patent a 4 bar linkage (which is what the mechanism looks like to me ... 2 4 bar linkages driven together) ?

 

[btrueblood]

If you don't care about the mechanical advantage of the lead screw mechanism, replace it with two pin links to either end of your cylinder.