I'm trying to build a step stool that has a rotating chair back that will rotate from top position (e.g. chair) into bottom position (e.g. step stool). I do not want a free rotation of the chair back so I want to avoid it slamming on the floor. I've been looking for a bearing that acts as a mechanical stepper to click every 15 degrees with enough force requirement to stop the chair back from falling to the ground without force being applied (other than gravity).

I've been searching google for a while now and cannot figure out what this part would be called.


It sounbds like you are describing a detent mechanism

Depending on the design this can be a positive lock like pin engaging with a hole which needs to be manually disengaged with each step or a 'soft' latch for example a ball bearing engaging with a conical pit which can be overcome just by applying a bit more force.

You can buy the sprung balls as a complete assembly which could then be mated to a disk with a shallow hole every 15 degrees.

Also a pawl and ratchet can be modified so that the teeth work like cams against a sprung pawl rather than providing a positive stop.


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