Abstract:
A computer system, or other electronic device, having two parts that are easily attached and quickly detached. One of the parts has a plurality of stakes projecting from one surface thereof, and the other part has a plurality of through openings for receiving the stakes, and a plurality of slots extending adjacent the stakes. The stakes are formed over the other part adjacent the openings to attach the second part to the first part, and a blade can be inserted in the slots to force the second part away from the first part and break the stakes to quickly detach the parts.

Description:
TECHNICAL FIELD 
     The present invention relates generally to computers, or similar electronic devices, and, more particularly, to such devices having quick detachable, recyclable parts, and to a method of assembling and disassembling same. 
     Recycling of used or worn-out parts is becoming more and more commonplace, especially with the advent of Government standards and requirements requiring same. Many computers and other electronic devices have been designed for ease of assembly with little or no regard as to recyclability. As a result, the several subassemblies making up the device often consist of both recyclable and non-recyclable parts, or recyclable parts that require different recycling processes. As a result, parts that otherwise would be recyclable are prevented from being recycled. Thus, it is becoming more and more important to be able to utilize parts that are easily attached but quickly detached to enable one or both of the parts to be recycled. 
     Computers, for example, are manufactured and assembled by attaching individual parts together to form subassemblies which, in turn, are built into the final assembly. The individual parts are often fabricated from metal or plastic and are usually attached by screws, heat staking, welds, adhesive, or the like, each of which has advantages and disadvantages with respect to assembly and disassembly. For example, the provision of screws, although making the parts fairly easy to detach, add to the cost of the computer and renders the assembly difficult to automate. 
     Heat-staking, on the other hand, enables two components, at least one of which is plastic, to be attached with relative ease using no additional parts, adding very little expense and employing automation techniques. Therefore, heat-staking would be a preferred production technique if the assembled parts could be quickly detached to enable one or both of them to be recycled. Unfortunately, heat staking does not lend itself to quick and easy disassembly since the most typical techniques used involve a hammer and chisel, or a motorized cutting tool, all of which are time-consuming and dangerous. Therefore, what is needed is a computer, or other electronic device that has parts that can be attached by a heat staking technique that retains all the above production advantages, yet enables the connected parts to be easily and quickly detached for recycling, or the like. 
     SUMMARY 
     Accordingly, a computer system, or other electronic device, having parts that are attached by heat-staking, is provided with all of the advantages thereof, yet can be easily and quickly detached. To this end, one of the parts has a plurality of stakes projecting from one surface thereof. The other part has a plurality of through openings for receiving the stakes, and a plurality of slots extending adjacent the stakes. The stakes are &#34;mushroomed&#34; over the other part adjacent the openings to assemble the parts, and a blade can be inserted in the slots to force the parts apart and break the stakes to quickly detach the parts. 
     An advantage is thus achieved since the parts can be attached utilizing heat stakes with all of their production advantages, yet the assembled parts can be easily and quickly detached. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram of a computer including a chassis and several components located in the chassis. 
     FIG. 2 is an exploded perspective view of a cover/shield assembly designed to cover the chassis of FIG. 1 and which is formed by two parts that are assembled utilizing a heat-staking technique. 
     FIG. 3 is a view similar to that of FIG. 2 but showing the two parts of FIG. 2 assembled but before the heat-staking technique is employed. 
     FIG. 4 is an enlarged, partial, perspective view of the portions of the assembled parts shown in the circle in FIG. 3. 
     FIG. 5 is a cross-sectional view taken along the line 5--5 of FIG. 4. 
     FIG. 6 is a view similar to that of FIG. 4 but showing the two parts of FIG. 2 after the heat-staking technique has been completed. 
     FIG. 7 is a cross-sectional view taken along the line 7--7 of FIG. 6. 
     FIG. 8 is a view similar to that of FIG. 6 but depicting a disassembly technique. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment may be utilized in connection with a personal computer shown in general by the reference numeral 1, which can be in the form of a desktop computer, a laptop computer or a tower computer. The personal computer 1 includes a processor 2, a memory 3, and a plurality of input/output (I/O) devices 4, all contained within a chassis 5. Two buses 6 and 7 are also provided that connect the processor 2 to the memory 3 and to the input/output devices 4, respectively, it being understood that other electrical traces (not shown) are provided for connecting the components of the computer 1. A mother board 8 is also contained in the chassis 5 for mounting and interconnecting various electrical circuits and related devices. Since the computer shown in FIG. 1 is conventional, it will not be described in any further detail. 
     FIG. 2 depicts a cover/shield assembly designed to cover the chassis 5 of FIG. 1 and which includes a plastic cover 10, shown upside down for the convenience of presentation. The cover 10 includes a top plate 12, two side walls 14a and 14b, and a front wall 14c extending perpendicular to the top plate. Preferably, the cover 10 is injection molded from a plastic material with the top plate 12 and the walls 14a-14c extending integrally, in a conventional manner. 
     A plurality of heat stakes 16 are formed on the inner, or lower, surface of the top plate 12 and are also formed of plastic material and integrally with the top plate. The heat stakes 16 are in the form of relatively small hollow posts that project slightly downwardly (upwardly as viewed in FIG. 2) from the plane of the top plate 12 and are spaced along and across the top plate. According to the example of FIG. 2, there are twenty heat stakes 16 so formed on the top plate, it being understood that this number can vary depending on the particular application. An indentation 18 is formed in the lower surface of the top plate 12 adjacent six of the heat stakes 16 and a flange 19, projects downwardly from the top plate 12 adjacent the center portion of the rear end thereof, all for reasons to be described. 
     A metal shield 20 is also provided that is attached to the inner surface of the top plate 12 and has a length and width that substantially correspond to the length and width of the top plate. The purpose of the shield 20 is to shield against electromagnetic and radio frequency interference and provide structural support to the top plate 12. To the latter end, a central beam 22 extends from front-to-back of the shield 20 and is formed integrally with the shield by bending the center portion of the shield accordingly. 
     A plurality of openings 24 are provided through the shield 20 in the same spacing pattern as the heat stakes 16 of the top plate 12. The diameters of the openings 24 are slightly larger that the diameters of the heat stakes 16 so as to receive the heat stakes, as will be described. Six slots 26 are provided through the metal shield 20 and correspond in number and location to the indentations 18 formed in the top plate 12 adjacent the corresponding heat stakes 16. The shield 20 also has six embossed portions 28 extending at the respective ends of the slots 26 for reasons to be explained. 
     To assemble the shield 20 to the cover 10, the shield is initially lowered from its position shown in FIG. 2 to the position of FIG. 3 in which the lower surface (as viewed in FIG. 3) of the shield engages the upper surface of the top plate 12. In this condition, the openings 24 in the shield extend around the respective heat stakes 16 of the cover 12, and the slots 26 formed in the shield align with the respective indentations 18 in the top plate 12. Also, the flange 19 of the cover 12 extends in the rear end of the central beam 22 of the shield. 
     FIG. 4 depicts the slot 26, the embossed portion 28 and the heat stake 16 shown in the circle in FIG. 3. It is noted that a shoulder 18a is formed in the top plate 12 as a result of the indentation 18 and is spaced from the end of the slot 26. The slot 26, the embossed portion 28, and the heat stake 16 shown in FIG. 4 are identical to the other slots, embossed portions and heat stakes also shown in FIG. 3. 
     With reference to FIG. 5, the shield 20 is secured to the cover 10 by an automated machine 30 which is brought down over each heat stake 16. It is understood that the machine 30 is adapted to apply energy, such as heat and pressure, to the heat stake 16 to the extent that the plastic material of the heat stake melts slightly and &#34;mushrooms&#34; over the shield 20 as shown in FIGS. 6 and 7. Since the machine 30 is of a conventional design, it is shown schematically and will not be described in any further detail. This step is repeated with the other five heat stakes 16 that are located adjacent an indentation 18 to further secure the shield 20 to the cover 10. It is noted that the heat stakes 16 which are not adjacent an indentation are not treated in the foregoing manner but extend in their corresponding openings 24 in the shield 20 to guide the shield and prevent lateral movement of the shield relative to the top plate 12. The shield 20 is thus attached to the cover 10 and the cover/shield assembly thus formed can be placed over the chassis 5 (FIG. 1) in a conventional manner. 
     If it is desirable to recycle the plastic cover 12 and the metal shield 20 after the computer 1 of FIG. 1 is no longer usable, the shield 20 must be disassembled from the cover 10 since they require different recycling processes. To this end, and with reference to FIG. 8, a standard screwdriver 32, having a flat blade 32a, is placed in the position shown in which it rests on the upper edge of the shoulder 18a. The blade 32a is then inserted further into the slot 26 and under the embossed portion 28 of the shield 20. The handle of the screwdriver 32 is then pushed downwardly, causing the blade 32 to pivot about the upper edge of the shoulder 18a thus creating leverage and a mechanical advantage. The blade 32a thus applies an upwardly-directed force (as viewed in FIG. 8) against the embossed portion 28 to force the shield 20 away from the plate 12 so that the &#34;mushroomed&#34; portion of the heat stake 16a is broken off with a relatively small effort. The other &#34;mushroomed&#34; heat stakes 16a are removed in the same manner, thus enabling the shield 20 to be quickly detached from the cover 10 and both the shield and the cover to be recycled separately. 
     The foregoing embodiment thus enjoys the advantages of using the heat stakes 16a, with their attendant production advantages, while permitting the cover 10 and the shield 20 to be easily connected and quickly disconnected. 
     It is understood that variations may be made in the foregoing without departing from the scope of the present invention. For example, the present invention is not limited to the assembly and disassembly of a cover and shield but is equally applicable to any other parts of a computer. Also, the present invention is not limited to a computer but can be equally applied to any device having parts that are connected. Also, it is understood that the present invention is not necessarily limited to assembling parts while permitting their disassembly for the purpose of recycling, but rather is equally applicable to any application where easy and quick disassembly is desired. Further, the two parts to be assembled and disassembled do not necessarily have to be made of plastic and metal respectively, but rather can be made of other materials consistent with the objects and achievements of the present invention. Still further, the number of heat stakes, slots, indentations, and embossed portions can be varied within the scope of the invention. 
     It is understood that other modifications, changes and substitutions are intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.