Patent ID: 8179669

Claim:
A retractable USB memory stick, comprising: a metal casing that is a seamless flat tube extruded from a metal material, having opposing front opening and rear opening, a sliding slot located on one peripheral wall thereof, and at least one first locating hole and one second locating hole located on said sliding slot at different locations; a PC board, said PC board comprising a USB interface circuit and a memory IC package disposed at a front side of said PC board; and an insulation PC board holder slidably mounted in said metal casing, said insulation PC board holder comprising a base portion, a front extension configured subject to a standard USB plug, a recess defined in said base portion and said front extension at a bottom side for securing said PC board, a spring strip bridged on said base portion, a sliding block located on said spring strip and forced by the spring power of said spring strip into said sliding slot of said metal casing, and a retaining block protruded from said sliding block for selectively engaging said first locating hole or said second locating hole of said metal casing to lock said insulation PC board holder to said metal casing in one of an extended position and a received position; wherein said sliding slot is located on the top wall of said metal casing; wherein said metal casing further comprises a third locating hole located on said sliding slot; said insulation PC board holder comprises a shackle that has a first end connected to said base portion of said insulation PC board holder and a second end spaced from said base portion by a gap; when said retaining block is engaged into said third locating hole of said metal casing, said insulation PC board holder is received inside said metal casing, and the gap defined between the second end of said shackle and said base portion is kept outside said metal casing.