In article . ca,
"jtaylor" wrote:

In my head I have a kind of picture how a rotary table might be made.

You have a base, with a central pivot (could be bored for a taper). Around
the pivot is a gear & the table, driven by a worm.

Some of these tables are advertised to have a method by which the table can
be decoupled from the gear, to allow quick rotation without turning the
worm. I have been turning this picture around and around in my head and
cannot figure out how they do this.

Someone tell me or point to a drawing, please...



Any method of shifting the motor/shaft such that the worm unmeshes from
the wheel would work - Here's a few I came up with "on the fly": Maybe
the whole motor/worm assembly pivots on an axis 90 degrees to the center
line of the shaft the worm is mounted on, turning it off of the wheel.
Maybe the motor/worm assembly pivots toward/away from the wheel,
allowing it to be "lifted off" the wheel. Maybe the wheel "floats" on
the pivot point the same way the clutch-disk in a car with a manual
transmission does on the tranny's input shaft - Shaft is splined, inside
of clutch disk/wheel is splined to match, but loose enough to slide, and
something similar to a car's throwout bearing (or perhaps shift-fork...)
rises and/or falls to boost and/or drop the wheel above/below the point
where it can mesh with the fixed-location worm to be driven. Maybe the
worm and wheel are permanently meshed, but something like a pair of
crown rings mesh to connect the table to the wheel - separating those
rings would accomplish the task.

The list of possibilities is probably a close relative to the Energizer
Bunny, since they both go on and on and on and...

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