Screw cap for a portable electronic device

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.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to screw caps that cover heads of screws, and more particularly to screw caps for portable electronic devices. The invention relates to a contemporarily filed application titled “EXPANDABLE SCREW COVER” and having the same assignee with the instant invention.

2. Prior Art

Nowadays, major parts of a portable electronic device such as a mobile phone are generally attached together with screws. Where one of the parts is the housing of the mobile phone, the head of each screw is conventionally exposed at an outer surface of the housing. This detracts from the aesthetic appearance of the mobile phone. Therefore in more recent times, manufacturers have configured a motherboard to be attached to a first half-shell of a housing of the mobile phone with screws, with a second half-shell of the housing being attached to the first half-shell by other means such as snap-fitting. In this way, the heads of the screws are hidden within the housing. For example, ERICSSON's mobile phone model no. T68 adopts the above-mentioned newer type of securing means.

However, assembly of the above-mentioned new kind of portable electronic device is much more complicated than assembly of the more conventional, less aesthetic type of portable electronic device. Therefore, some modem portable electronic devices still adopt securing of an upper cover to a lower cover thereof with screws. In addition, a cylindrical cap made of soft plastic is engaged in each screw hole so that it covers the screw head. The diameter of the cap is slightly larger than the diameter of the screw hole, so that the cap interferentially fits in the screw hole and does not fall out. For example, SAMSUNG's mobile phone model no. N188 adopts this type of aesthetic securing means. However, in disassembly, a hard, sharp tool needs to be inserted between the cap and the housing. The caps have to be removed from the housing one by one, which is very laborious. Moreover, because the caps are made of soft plastic, they are easily damaged and distorted during normal use of the portable electronic device. This not only reduces their aesthetic appearance, but can also make disassembly more difficult and inconvenient.

Therefore, a screw cap for a portable electronic device which overcomes the above-described disadvantages is desired.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a screw cap for a portable electronic device which enables the portable electronic device to be conveniently assembled and disassembled.

To achieve the above-mentioned object, a screw cap for a portable electronic device of the present invention comprises a main body and an elastic ring. The main body comprises a head located a top thereof, and a cylindrical body adjoining a bottom of the head. An outer diameter of the cylindrical body is less than an outer diameter of the head. A first groove and a second groove are defined in circumferential surface of the cylindrical body. The first groove is near a top of the cylindrical body, and is deeper than the second groove. When the elastic ring is engaged in the second groove, the screw cap can be interferentially engaged in a screw hole of a housing of the portable electronic device. 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.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1, a screw cap of a portable electronic device in accordance with the preferred embodiment of the present invention comprises a main body12and an elastic ring14that has a gap (not labeled) therein. The main body12includes a head122and a cylindrical body124. The head122is located at the top of the main body12, with the cylindrical body124adjoining a bottom of the head122. The head122and the cylindrical body124can be integrally formed together at the same time. An outer diameter of the cylindrical body124is less than an outer diameter of the head122. An upper first groove1242and a lower second groove1243are respectively defined in a circumferential surface of the cylindrical body124. The first groove1242is near a top of the cylindrical body124, and is deeper than the second groove1243. A stop block1244is formed on the cylindrical body124. The stop block1244protrudes from the circumferential surface of the cylindrical body124below the second groove1243. The elastic ring14can be engaged in the first groove1242or the second groove1243, and can be taken out from the first or second grooves1242,1243by manipulating the elastic ring14at the gap thereof. As shown inFIG. 5, when the elastic ring14is engaged in the second groove1243, an outer diameter of the elastic ring14is greater than the diameter of the head122. As shown inFIG. 4, when the elastic ring14is engaged in the first groove1242, the outer diameter of the elastic ring14is less than the diameter of the head122.

Referring toFIG. 2, the portable electronic device utilizing the screw cap comprises a housing2, and a screw hole20defined in the housing2. The screw hole20is stepped, and thereby comprises an upper portion202and a lower portion204. A diameter of the upper portion202is greater than a diameter of the lower portion204. The diameter of the upper portion202is slightly greater than the diameter of the head122, so that the head122can be fittingly received in the upper portion202. The diameter of the lower portion204is slightly greater than the diameter of the cylindrical body124, so that the cylindrical body124can be fittingly received in the lower portion204. An annular supporting step206is defined at the junction of the upper portion202and the lower portion204. A vertical sliding groove207is defined in an inner wall of the housing2at the lower portion204, with a top extremity of the sliding groove207being at the supporting step206. A stop step208is defined at a bottom of the sliding groove207. The stop block1244of the cylindrical body124can slide in the sliding groove207and can be stopped by the stop step208. In addition, the outer diameter of the elastic ring14in an uncompressed state in the second groove1243is slightly greater than the diameter of the upper portion202.

Referring also toFIG. 3, in assembly, a screw (not shown) is mounted in the screw hole20of the housing2. The elastic ring14is invaginated into the second groove1243of the main body12. The screw cap is then inserted into the screw hole20. The head122is pressed down. The main body12slides into the screw hole20, with the elastic ring14interferentially sliding down along the upper portion202, and the stop block1244sliding down in the sliding groove207. The head122is thus pressed until a top face thereof is level with or lower than a top face of the housing2. This position can be attained because a distance between the second groove1243and the top face of the head122is less than a depth of the upper portion202of the screw hole20. In addition, because the outer diameter of the elastic ring14in the uncompressed state in the second groove1243is slightly greater than the diameter of the upper portion202, the screw cap is tightly fixed in the screw hole20.

Referring toFIG. 4, in disassembly, the head122is pressed down. The elastic ring14slides with the main body12in the upper portion202toward the supporting step206. Because the outer diameter of the elastic ring14in the second groove1243is greater than the diameter of the lower portion204of the screw hole20, the elastic ring14is stopped by the supporting step206. When the head122is continued to be pressed, the cylindrical body124interferentially slides down through the elastic ring14. Thus the elastic ring14is disengaged from the second groove1243, and moves relative to the cylindrical body124until it eventually engages in the first groove1242. In this position, because the outer diameter of the elastic ring14in the first groove1242is less than the diameter of the head122, the screw cap is in no longer tightly fixed in the screw hole20. The portable electronic device is then inverted, so that the screw cap drops out from the screw hole20.

It is believed that the present invention and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages. The examples hereinbefore described are merely preferred or exemplary embodiments of the invention.