rotary actuators problem

Sure - the simple solution is using a cantered pivot and have a circular spindle with location "V" slots at 90deg intervals (4 quadrant points) and a spring loaded pin (v-point) attached to the frame to inhibit movement at these quadrant points. Anti-reversal is easily accomplished by a wipe brake using the spindle and attached to the frame. The degree of accuracy is dependent upon the sharpness of the v-point pin, the sharpness and matching of the v-slots on the spindle, and the spindle diameter. There are of course a number of other ways of delivering similar results and to design a specific solution for your situation would require details including sizes, load bearing requirement, aspect, environment (hazards), drive system, purpose, etc.

"DG" wrote

Sounds like a great application for a "Geneva mechanism". Or am I missing something?

-- TP

I was kind of thinking along the lines of some sort of ratchet device driven by an air cylinder. Seem to be plenty of ratchet/pawls on the market but don't seem to see any assemblies pre-made. suggestions?

the table needs to stop at the 90 degree increments for different time lengths

Ned Simmons

The Geneva Cross mechanism gives 90 deg increments of a driven wheel for each revolution of the driver wheel.

Brian Whatcott altus OK

Right on, TP! a "Geneva" it is.

cheers Bob

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