The device is called a selector switch, and it allows the user to adjust the gap between flags, which in turn provide faster of slower pick up of a printed eye mark (registration mark) of substrate (paper in this case) which is moving into a die to be cut. Correct print registration to the die cutting position is essential, and must not vary beyond 1/32".

I'm curious about the part in the picture.

I've tried to look it up on GE's website, but no luck.

Any insights into it's construction, function would be appreciated.

I'm trying to make a layman's training document for how and when to use the adjustment of Advance / Retard Flags on the EMP HSS-9 Selector Switch.
Part number is GE 8646 A22A1, and it's not magnetic
Thanks,
Gary

 

it is not exactly a selector switch (it could be used as one if stroke is limited), it is a 2-channel encoder. black slotted devices are opto-interruptors consisting of optical sender and receiver (like optocoupler but the line of sight can be obstructed by a flag).

http://www.digikey.com/product-sear...pe-transistor-output/1967054?k=slotted sensor

 

Thank you very much