Patent ID: 7588299

Claim:
A rail assembly comprising: a substantially U-shaped first rail having two sidewalls and a first space defined between the two sidewalls; a substantially U-shaped rail movably received in the first space and including two sidewalls with a second space defined between the two sidewalls of the second rail, an escape space defined inward from an underside of the second rail; a substantially inverted U-shaped third rail movably received in the second space; and a retrieving unit including a fixed member which is fixedly located in an end of the first rail and received in the first space, an extension rail extending from the fixed member and located in the first space, a movable member slidably connected to the extension rail, the extension rail being sized to be received in the escape space of the second rail, the movable member including two upright sides and the two sidewalls of the third rail being guide by two respective insides of the two upright sides, two groove defined in a top on two sides of the fixed member and the two sidewalls of the third rail slidably engaged with the grooves, a connection member located on a top of the movable member and the third rail disengageably engaged with the movable member by the connection member, the connection member including a first protrusion and a second protrusion extending from an underside of two ends thereof.