Please refer to FIG. 4. The first pivot section 111 and the second pivot section 122 are pivotally turnably connected to each other via a shaft 150. However, it is understood the first and the second pivot section 111, 122 can be otherwise connected together via a hinge structure or be engaged with each other via an engaging structure.

The pulling member 110 is provided with a first limiting unit 113. When the handle member 120 is located at the pulled-out position, the first limiting unit 113 interferes with a second limiting unit 212 provided on the first partitioning wall 210 to limit a maximum length by which the pulling member 110 can be pulled out beyond the first partitioning wall 210. In the first embodiment, the first limiting unit 113 is an elongated hole, and the second limiting unit 212 is a protruded body adapted to be correspondingly received in the above-mentioned elongated hole. In practical implementation of the present invention, the protruded body can be a screw, a nut or a rivet locked to the first partitioning wall 210. It is understood the first limiting unit 113 and the second limiting unit 212 are not necessarily limited to the above-described structure. For example, the first limiting unit 113 can be otherwise an elongated slot, while the second limiting unit 212 can be a hooked body adapted to be correspondingly received in the elongated slot. Alternatively, the second limiting unit 212 can be an elongated hole or an elongated slot, while the first limiting unit 113 can be a protruded body or a hook adapted to be correspondingly received in the elongated hole or the elongated slot.