"Clutch" for a drill press. To drill and tap smaller holes.

[crazypj]

The outer tube is connected to large chuck. The 'bolt' inside is free to rotate. The spring provides pressure for 'clutch' (the large washer and flange) If too much torque is applied, the 'bolt' will stop spinning and clutch slips. The outer tube keeps spinning. If the outer tube was threaded and a flanged nut used, the clutch would become adjustable as spring pressure can be adjusted. It's actually quite clever to adapt this to small drills/taps although also quite easy to 'go overboard' and add too many 'features' (I should make one but I know I would keep adding things defeating purpose of simple tool - LOL)