Assembly structure for assembling a first plastic shell and a second plastic shell

An assembly structure for assembling a first plastic shell and a second plastic shell, thereby coupling articles to be assembled such as keyboards and adapters, including a hollow strut and an opening. The first plastic shell has the hollow strut extended from the inner side. The second plastic shell has the opening defined therein and corresponding to the hollow strut and extends inwards to form an annular flange abutting the hollow strut. The hollow strut has a portion extended through the annular flange to be melted by the ultrasonic welding technique, the thermal welding technique, or the combination thereof until reaching the annular flange, to couple the first and second plastic shells for facilitating assembly. Grinding off the melted portion may disassemble the first and second plastic shells. The disassembled the first and second plastic shells may be coupled again by fastening a fastening element in the hollow strut with the head of the fastening element held by the annular flange.

FIELD OF THE INVENTION

The present invention relates to an assembly structure for articles requiring assemblage such as keyboards, adapters, and the like and particularly to a structure that employs the ultrasonic welding technique, the thermal welding technique, the combination thereof, or any other welding techniques to couple two plastic shells to facilitate assembling.

BACKGROUND OF THE INVENTION

There are many ways to assemble articles. The following uses a keyboard as an example for discussion. The keyboard is a data input device to function as a communication interface between users and a computer system. It consists of many keys that include character keys, direction keys and function keys and the like, for entering different data. The keyboard has many types. Most keyboard shells are assembled with tapping screws engaging apertures. While fastening by the tapping screws, the shells often deform due to torsion force and stress. Deformation is especially severe when the shells are lengthy. Even the gaps between the shells and the tapping screws result in a bad surge-test or a bad high-pressure-test. So fastening the shells by the tapping screws is not a facilitating way.

At present the technique of coupling through an ultrasonic welding process has been adopted in many areas. Reference can be found in U.S. Pat. Nos. 5,475,919 and 6,546,621.

U.S. Pat. No. 6,546,621 entitled “Package structure and method for a card” teaches a technique, which couples a first conductive cover and a second conductive cover with a first plastic frame and a second plastic frame by ultrasonic welding, to form a first half case and a second half case. U.S. Pat. No. 5,475,919 entitled “PCMCIA card manufacturing process” also adopts the ultrasonic welding technique to couple an upper plastic case with a lower plastic case. However, the product coupled by the ultrasonic welding technique has one problem, i.e. when it is disassembled for repairs, the welding structure is destroyed and the plastic cases have to be discarded. This results in wasting of costs.

SUMMARY OF THE INVENTION

An advantageous feature of the preferred embodiments of the present invention is to provide an assembly structure for assembling a first plastic shell and a second plastic shell that employs the ultrasonic welding technique, the thermal welding technique, or the combination thereof, to couple and assemble articles (such as keyboards, adapters, and the like.

The assembly structure for assembling a first plastic shell and a second plastic shell of the invention includes a hollow strut and an opening. The first plastic shell has the hollow strut extended from an inner side. The second plastic shell has an opening defined therein and corresponding to the hollow strut and is extended inwards to form an annular flange abutting the hollow strut. The hollow strut has a portion extended through the annular flange. After fused by the ultrasonic welding technique, the thermal welding technique, or the combination thereof, the portion of the hollow strut that is extended through the annular flange is melted on the annular flange to couple the first plastic shell and the second plastic shell together.

The annular flange can prevent the melted portion from flowing into the first and second plastic shells or from flowing to other places while melting of the melted portion. Disassembly of the first and second plastic shells may be accomplished by grinding off the melted portion. Then a fastening element, such as a tapping screw, may be used to run through the hollow strut to couple the first and second plastic shells again, while the head of the tapping screw is held by the annular flange.

The foregoing, of course, may possess none, one, some, or all of these technical features and/or additional technical features. Other technical features will be readily apparent to those skilled in the art from the following figures, detailed description, and/or claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention aims to provide an assembly structure for assembling a first plastic shell and a second plastic shell, which uses the ultrasonic welding technique, the thermal welding technique, the combination thereof, or other techniques that can weld two plastic shells, to couple and assemble the two plastic shells for facilitating assemblage of an article. After the plastic shells have been disassembled, they can be assembled again and reused. The article that consists of two plastic shells may be a keyboard, an adapter or the like.

Refer toFIG. 1Afor a first embodiment of the invention before coupling by the ultrasonic welding technique, the thermal welding technique, or the combination thereof, andFIG. 1Bafter the first embodiment has been coupled. The assembly structure for assembling a first plastic shell and a second plastic shell according to the invention includes a hollow111strut and an opening21. In detail, the first plastic shell10has the hollow strut111extended from an inner side11. The hollow strut111has a retaining section1111. The second plastic shell20has the opening21defined therein and corresponding to the hollow strut111. The opening21is extended inwards to form an annular flange211abutting the hollow strut111. The hollow strut111may be extended through the annular flange211with the annular flange211held by the retaining section1111. The periphery of the opening21further is extended outwards to form an annular retaining wall212. After being fused by the ultrasonic welding technique, the thermal welding technique, or the combination thereof, a portion of the hollow strut111that is extended through the annular flange211is melted on the annular flange211, to couple the first plastic shell10and the second plastic shell20together.

In the process of assembling the first plastic shell10and the second plastic shell20, first, have a portion of the hollow strut111running through the opening21close to the annular flange211until the annular flange211is stopped by the retaining section1111. Then move a mold30to the hollow strut111to melt the extended portion of the hollow strut111until reaching the annular flange211to couple the first plastic shell10and the second plastic shell20together. To prevent the melting plastics from flowing to other places, the following designs may be adopted, such as the mold30having a retaining portion31to run through the hollow strut111to prevent the melted portion from flowing into the hollow strut111, the annular flange211being able to prevent the melted portion from flowing into the first plastic shell10and the second plastic shell20, and the annular retaining wall212being able to prevent the melted portion from flowing outside.

Disassembly of the first plastic shell10and the second plastic shell20may be accomplished by grinding off the melted portion (shown inFIG. 1C). Then a fastening element such as a tapping screw40may be used to run through the hollow strut111, to couple the first plastic shell10and the second plastic shell20again (shown inFIG. 1D), while the head of the tapping screw is held by the annular flange211.

Refer toFIG. 2Afor a second embodiment of the invention before coupling by the ultrasonic welding technique, the thermal welding technique, the combination thereof, andFIG. 2Bafter the second embodiment has been coupled. The assembly structure for assembling a first plastic shell and a second plastic shell according to the invention includes a hollow111strut and an opening21. In detail, the first plastic shell10has the hollow strut111extended from an inner side11. The hollow strut111has a smaller thickness on the upper edge and becomes gradually thicker toward the inner side11to form a trench112on the thicker portion with an annular wall113extended outwards from the inner periphery. The second plastic shell20has the opening21defined therein and corresponding to the hollow strut111. The opening21is extended inwards to form an annular flange211abutting the hollow strut111. The hollow strut111may be extended through the annular flange211with the annular flange211retained by the retaining section1111. The periphery of the opening21further is extended outwards to form an annular retaining wall212. After being fused by the ultrasonic welding technique, the thermal welding technique, or the combination thereof, the portion of the hollow strut111that is extended through the annular flange211is melted on the annular flange211, to couple the first plastic shell10and the second plastic shell20together.

In the process of assembling the first plastic shell10and the second plastic shell20, first, have a portion of the hollow strut111running through the opening21close to the annular flange211until the annular flange211is stopped by the retaining section1111. Then move a mold30to the hollow strut111to melt the extended portion of the hollow strut111until reaching the annular flange211, to couple the first plastic shell10and the second plastic shell20together. To prevent the melting plastics from flowing to other places, the following designs may be adopted, such as making the melted portion flow into the trench112without flowing into the hollow strut111, the annular flange211being able to prevent the melted portion from flowing into the first plastic shell10and the second plastic shell20, and the annular retaining wall212being able to prevent the melted portion from flowing outside.

Disassembly of the first plastic shell10and the second plastic shell20may be accomplished by grinding off the melted portion. Then a fastening element such as a tapping screw may be used to run through the hollow strut, to couple the first plastic shell10and the second plastic shell20again (not shown in the drawing), while the head of the tapping screw is held by the annular flange211.

In addition, when the sizes of the first plastic shell10and the second plastic shell20are not very large, the retaining structure interposed between the first plastic shell10and the second plastic shell20may be omitted. Once melted, the portion of the hollow strut111extended outside the opening21is melted until reaching the edge of the opening21, to couple the first plastic shell10and the second plastic shell20. After grinding off the melted portion of the hollow strut111, the first plastic shell10and the second plastic shell20may be disassembled. A fastening element (not shown in the drawings) may be used to run through the hollow strut111, to couple the first plastic shell10and the second plastic shell20again.

When the retaining structure, which is on the first plastic shell10or the second plastic shell20, is built-in around the opening21the additional retaining structure may also be omitted.