I was out prospecting and came across this triple
bellows drywasher setup. Very interesting how the bellows were
setup more like piston bellows, no cloth. The hopper above had
an offset rotating weight to create a vibration to screen better.
Also each bellows had the upper end suspended in coil springs.
This creates a riffle up down vibration as the bellows works.
Rear view of the triple drywasher. Note two motors, one for
bellows and one for hopper.
Close up of the riffle trays. Notice they pivot at lower end and
are free to move at upper end by stroke of bellows. They only
move an inch or less due to the spring arrangement. Also note
the feed doors above the riffles. They are ganged together
to one lever.
Here we see the hopper motor and offset weight that shakes the
hopper. The hopper is sitting on coil springs to allow it to shake.
This is behind the bellows showing the crankshaft and gear
reduction to make it all happen. Also shown are the bellows
stops that limit the movement of the hinged bellows and riffle
tray system. There is no bellows cloth only a fixed chamber for
a moving plate to move up and down like a piston in a motor.
This was a very interesting piece of equipment with a lot of
ingenious ideas used through out its design.