Old Tool ID

[Chris Padilla]

Any idea what this tool is and its purpose?

[Jim Matthews]

First glance, I would have said it's a chainfall - but the escapement mechanism indicates a ratchet.
If there's a spring, I would guess it's a retractable chain as a tether.

Like a keychain, on steroids.

Perhaps it was used in an assembly setting, where something heavy needed to be easy to retrieve but raised after use?

[Lee Schierer]

I think it is a damper control for a coal or wood fired furnace. It mounts in the living space above the furnace and you can control the temperature coming through the heat vent by opening or closing the damper on the furnace. My Grandfather had a similar one made of brass in his house in Bradford, PA.