I'm not sure I understand the question. You have to convert reciprocating
motion to rotary motion; the former so you can have a seal at the output end
of the cylinder. PhDs have been granted for work on/analysis of "four bar
linkages," but the scheme shown is almost identical to that found on steam
locomotives to the end of their reign. Simple to build and repair!
Lee Valley sells a book, "Mechanical Movements," which basically consists of
hundreds of patent drawings from about 1900. Many, many schemes for such
devices are shown.
What's shown is sure better than the "grasshopper" linkage of the first
(I'd call the yoke a "cross-head" and the "Pittman arm" a "connecting rod."
The connecting rod is not the piston rod.)
----- Original Message -----
From: "STEVE BOSQUETTE" <mainesal5@...>
> Take a look at the site below, Could we come up with an even simpler
> way to engage the sternwheel using a pitman arm?
> Steve Bosquette