In the second variation of the second embodiment, the pulling member 110 has a first limiting unit 113. When the handle member 120 is in 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 second variation of the second embodiment, the first limiting unit 113 is, for example, 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.

In this case, the pulling member 110 can have an L-shaped or a hook-like configuration and includes a first pivot section 111 formed at an extended bent portion of the L-shaped or hook-like pulling member 110. The first pivot section 111 is pivotally connected to the second pivot section 122.

FIG. 18 shows a third variation of the second embodiment of the present invention.