A rail is screwed into the ceiling.
Along this rail runs two hangers -- each with two nylon wheels.
Below the nylon wheels is a horizontal metal wheel with "notches" along its edge.
Extending down from this metal wheel is a vertical bolt that is screwed int o the top of the closet door.
There's a nut at the top of the vertical bolt. The nut is tight against th e bottom of the horizontal metal wheel.
To raise the door so it clears the carpet, do I first move the nut down the bolt then turn the metal wheel -- do I turn the metal wheel clockwise or c ounter-clockwise? -- then move the nut up the bolt until the nut is tight a gainst the bottom of the metal wheel?