Abstract: A screw cap for covering a head of a screw in a screw hole (20) of a housing (2) of a portable electronic device. The screw hole includes a wide upper portion (202) and a narrow lower portion (204). The screw cap includes a main body (12) and an elastic ring (14). The main body includes a wide head (122) and an adjoining narrow cylindrical body (124). An upper first groove (1242) and a lower second groove (1243) are defined in the cylindrical body. The first groove is deeper than the second groove. When the elastic ring is engaged in the second groove, the screw cap can be interferentially engaged in the screw hole. When the screw cap is pushed so that the elastic ring is engaged in the first groove, the screw cap can be easily removed from the screw hole.

Abstract: An automatic antenna (100) for a portable electronic device includes a shaft (20), a hollow securing element (30), a sliding element (50) having a plurality of sliding arms (54) symmetrically disposed on an outer wall thereof, a hollow rotating element (60), a housing (80), and a spring (70) disposed between the rotating element and the housing. The securing element has a plurality of blocks (320) symmetrically disposed on an inner wall thereof. The blocks define a plurality of slots (3200) therebetween. The sliding element defines an end surface (56). The rotating element includes a peripheral cam portion (61). A plurality of projections (604) protrudes from a periphery of the cam portion. The shaft extends through the securing element, the sliding element, the rotating element, the spring, and the housing in that order. The sliding arms can slide within the slots, and the projections can slide in the slots.

Abstract: An automatic antenna (100) for a portable electronic device includes a shaft (20), a hollow securing element (30), a sliding element (50) having a plurality of sliding arms (54) symmetrically disposed on an outer wall thereof, a hollow rotating element (60), a housing (80), and a spring (70) disposed between the rotating element and the housing. The securing element has a plurality of blocks (320) symmetrically disposed on an inner wall thereof. The blocks define a plurality of slots (3200) therebetween. The sliding element defines an end surface (56). The rotating element includes a peripheral cam portion (61). A plurality of projections (604) protrudes from a periphery of the cam portion. The shaft extends through the securing element, the sliding element, the rotating element, the spring, and the housing in that order. The sliding arms can slide within the slots, and the projections can slide in the slots.