Shelf with height and angle adjustment

Claim 1

A shelf comprising: a pair of rails, spaced from one another in a parallel relationship, adapted to be mounted vertically on a wall; a rectangular frame including a first elongated plate having two ends and disposed between said pair of rails, and a second elongated plate which has a mounting hole and an end connected perpendicularly to one of the ends of said first elongated plate; an engaging member mounted between each end of said first elongated plate and each of said rails, said engaging member having a curved edge with a plurality of notches formed along said curved edge, said engaging member being slidably mounted on one of said rails along the length thereof; means for retaining said engaging member at a predetermined height along said rails, said means including a rod having two ends and a hollow tube having a first end connected to the mounting hole of said second elongated plate adjacent to said rail, each of said rails having a plurality of positioning apertures formed along its length, said hollow tube receiving the rod therein; resilient means provided in said hollow tube for urging one end of said rod to pass through said mounting hole of said second elongated plate, said engaging member and one of said positioning apertures of said rail in turn; the other end of said rod extending out of the free end of said hollow tube being connected to a pull member, said pull member retracting said end of said rod from said rail and said engaging member into said hollow tube when said pull member is moved away from said free end of said hollow tube, so that said frame can be moved along said rails; and means for selectively engaging said second elongated plate in one of said notches of said curved edge of said engaging member so as to form an adjustable angle between said second elongated plate and one of said rails.