Zipper assembly

A zipper fastener comprising:

• a pair of tapes facing each other, each of said tapes having a plurality of teeth attached thereto for fastening and unfastening operation;
• a slider having a generally C-shaped cross section with a top portion, a pair of side portions, and an open bottom portion;
• a locking unit attached to an end of one of said tapes, said locking unit including a pair of stoppers received in an inner space of the slider;
• and
• a bottom stop disposed below a corresponding end of the other one of said tapes and attached thereto, the bottom stop including an anchor protruding in an upward direction, said anchor configured to retractably position between said stoppers of the locking unit in response to an up and down movement of the bottom stop to selectively allow and disallow a sliding movement of the slider for the fastening and unfastening operation of the tapes,
• wherein the locking unit is configured to have a lock position with the pair of stoppers at a first position for locking the locking unit against the slider and with the anchor of the bottom stop not engaged between the pair of stoppers, a fastening position with the pair of stoppers at a second position for allowing fastening movement of the slider to fasten the teeth and with the anchor of the bottom stop engaged between the pair of stoppers, and an unfastening position with the pair of stoppers at a third position for allowing unfastening movement of the slider to unfasten the teeth while allowing disengagement of the anchor of the bottom stop from the pair of stoppers.