What is a Quarter-Turn Keeper?

What is a quarter turn keeper?

First lets mention that a quarter turn fastener is composed by a stud, a quarter turn keeper (a receptacle) and a retaining ring. All 3 of them are indispensable to fasten.

A quarter turn keeper is the hollow metal piece through which the quarter turn stud passes through and locks against. This object is normally screwed or welded on the frame. The cross pin at 90 degrees travels along the groove to sit on the gap which is lower than the rest of the groove.

With this action, the quarter turn keeper manages to keep the cross pin locked unless a vertical (usually downwards) force is applied in combination of a rotational motion to overcome the groove that blocks it from moving to either side.