WO2006137637A1

WO2006137637A1 - Multipurpose color duct made by aluminium to be usable as cable tray, raceway and duct

Info

Publication number: WO2006137637A1
Application number: PCT/KR2005/004670
Authority: WO
Inventors: Soon-Kyu Choi
Original assignee: Soon-Kyu Choi
Priority date: 2004-12-30
Filing date: 2005-12-30
Publication date: 2006-12-28
Also published as: KR100522583B1

Abstract

Disclosed is a multipurpose color duct made of aluminum and adaptable for a cable tray system, a raceway system, or a cable duct system. The multipurpose color duct includes an upper cover having a 'D' shaped structure, being provided at both side ends thereof with 'b' shaped protrusions and being formed on an upper surface thereof with at least one bending section for reinforcing tensile strength and load strength of the upper cover, and a lower body having a 'D' shaped structure corresponding to the upper cover, being provided at both side ends thereof with 's' shaped coupling sections and being formed on a bottom surface thereof with at least one bending section for reinforcing tensile strength and load strength of the lower body. The 'b' shaped protrusions of the upper cover are fixedly coupled with the 's' shaped coupling section of lower body.

Description

MULTIPURPOSE COLOR DUCT MADE BY ALUMINUM TO BE USABLE AS CABLE TRAY, RACEWAY AND DUCT

Technical Field

[1] The present invention relates to a multipurpose color duct made of aluminum and adaptable for a cable tray, a raceway or a cable duct. More particularly, the present invention relates to a multipurpose color duct made of aluminum, adaptable for a cable tray, a raceway or a cable duct, and including a coupling sections formed at an upper cover and a lower body of the multipurpose color duct. Background Art

[2] In general, a cable tray system 100, as shown in FIG. 1, refers to a structure for supporting wire cables by combining a metal cable tray section with accessory parts, such as straight sections 1, straight channel sections 2, horizontal channel fittings 3, vertical elbows 4, horizontal elbows 5, horizontal tees 6, horizontal crosses 7, horizontal Y branches 8, reducers 9, joint connectors 10, channel connectors 11, end plates 12, and end drop-out parts 13.

[3] Such a cable tray system 100 is generally suspended to the ceiling of the building in order to support the wire cables provided in each floor of the building.

[4] The cable tray system 100 shown in FIG. 1 is mainly divided into a ladder type cable tray system (see, FIG. 2), a channel type cable tray system (see, FIG. 3), a trough type cable tray system, and a combination thereof.

[5] FIG. 2 is a view illustrating a basic straight section 1 of a ladder type cable tray system 100. Referring to FIG. 2, the straight section 1 includes horizontal- axis support square plates 21 having a "D" shaped sectional structure, which is formed by means of a roller forming machine by using a hot coil steel plate having a thickness of about 1 to 5mm, a galvanized steel plate, or a stainless steel plate, and a longitudinal- axis support square plates 23 welded between the horizontal- axis support square plates 21. In order to form the cable tray system 100 as shown in FIG. 1, the straight section 1 is coupled with various accessory parts, such as straight channel sections 2, horizontal channel fittings 3, vertical elbows 4, horizontal elbows 5, horizontal tees 6, horizontal crosses 7, horizontal Y branches 8, reducers 9, joint connectors 10, channel connectors 11, end plates 12, and end drop-out parts 13, which are fabricated in the form of ladder structures identical to the straight section 1. Holes 25 are previously formed at the end portion of the straight section 1 in such a manner that the straight section 1 can be coupled with various accessory parts through bolts and nuts.

[6] FIG. 3 is a view illustrating the basic straight section 1 of the trough type or duct type cable tray system 100. As shown in FIG. 3, the trough type or duct type cable tray system 100 basically includes an upper plate 33, a lower body section 31, and clamps 39, which are coupled with each other so as to form a rectangular box structure. As shown in FIGS. 5, 7 and 8, the lower body 31 can be obtained by bending the straight channel section 2, the horizontal channel fitting 3, the vertical elbow 4, the horizontal elbow 5, the horizontal tee 6, the horizontal cross 7, the horizontal Y branch 8, the reducer 9, the joint connector 10, the channel connector 11, the end plate 12, and the end drop-out part 13. That is, as shown in FIGS. 5, 7 and 8, the lower body section 31 includes lateral parts 35 and upper wings 37 which are bent from the lateral parts 35 at a right angle.

[7] Referring to FIG. 3, the size of the upper plate 33 is slightly larger than that of the lower body section 31 in such a manner that the lower body section 31 can be precisely fitted into the upper plate 33. The upper plate 33 is simply put on the lower body section 31, so that the clamps 39 as shown in FIG. 6 are used in order to securely couple the upper plate 33 with the lower body section 31 as shown in FIG. 3. Each clamp 39 includes upper and lower clamp parts, which are coupled with each other by means of coupling units (not shown), such as bolts and nuts.

[8] FIG. 9 is a schematic view illustrating a raceway system 200, FIG. 10 is an exploded perspective view illustrating a straight section 250 of the raceway system 200, and FIG. 11 is a sectional view illustrating a connector 253 for connecting the straight sections 250 of the raceway system 200.

[9] Herein, different from the cable tray system 100 illustrated in FIG. 1, which is installed in a hidden place, such as a ceiling of a building, in order to support a thick coaxial cable, the raceway system 200 is installed in an exposed place, such as a wall part of the building as shown in FIG. 9. The raceway system 200 may include relatively thin wires therein and can be coupled with an outlet box or an illumination unit, if necessary.

[10] Such a raceway system 200 is coupled with a junction box 220 provided at cable branch portions or cable cross portions, an outlet box 230 installed in a desired place, and an illumination unit 240 installed in a predetermined place.

[11] The raceway system 200 includes straight sections 250 having shapes as shown in

FIG. 10. Each straight section 250 of the raceway system 200 includes a lower body 251, an upper cover 252, and a clamp 254 (see, FIG. 9).

[12] Referring to FIG. 10, the lower body 251 can be obtained by bending a steel plate in the form of a "D" structure and then inwardly winding both ends 255 of the "D" structure such that a connector 253 having a "D" structure can be fixedly inserted into the lower body 251. That is, the both ends 255 of the lower body 255 are bent in the form of a reverse-U shape and the connector 253 is inserted into the lower body 251 while engaging with the both ends 255 of the lower body 255. The upper cover 252 has a shape and a size sufficient for covering an opening section of the lower body 251.

[13] Since the upper cover 252 is placed on the lower body 251, the straight section 250 of the raceway system 200 may have the trough shape or the rectangular pipe shape. In addition, in order to securely couple the lower body 251 with the upper cover 252, a strip-shaped clamp is bent in the form of a "D" shaped structure, and then both ends of the "D" shaped structure are inwardly bent at a right angle. The clamp as shown in FIG. 6 can also be used.

[14] The straight section and accessory parts forming the cable tray system 100 or the raceway system 200 shown in FIGS. 1 and 2 are generally made of a galvanized steel plate or hot rolled iron, which is plated with a plating solution, in order to prevent erosion.

Disclosure of Invention Technical Problem

[15] However, the cable tray system 100 or the raceway system 200 as described above has disadvantages as follows:

[16] First, the structure of the straight section forming the above cable tray system 100 or the raceway system 200 is so simple that additional parts, such as a clamp, are necessary. Thus, it takes long time when installing and repairing the above cable tray system 100 or the raceway system 200.

[17] Second, since the connector of the above cable tray system 100 or the raceway system 200 is made of a non-elastic material, it requires a coupling unit, such as a bolt and nut assembly, so that relatively long time is necessary to install and repair the above cable tray system 100 or the raceway system 200.

[18] Third, since the parts of the above cable tray system 100 or the raceway system 200 are very sharp, the worker may be damaged by the sharp parts when installing or repairing the above cable tray system 100 or the raceway system 200 or the cable is worn by the sharp parts causing accidental firing.

[19] Fourth, since the galvanized steel plate or hot rolled iron is processed by means of a roller forming machine, an external appearance of the galvanized steel plate or hot rolled iron is degraded. In addition, since the galvanized steel plate or hot rolled iron must be plated with a plating solution, there exists a problem of environmental pollution.

[20] Therefore, the present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a multipurpose color duct made of aluminum and adaptable for a cable tray system 100 and a raceway system and a method for fabricating the same, in which the multipurpose color duct has a light weight as compared with that of a conventional stainless steel duct and can improve workability.

[21] Another object of the present invention to reduce the number of components by modifying the structure of the multipurpose color duct made of aluminum.

[22] Still another object of the present invention is to provide a multipurpose color duct made of aluminum and adaptable for a cable tray system and a raceway system, in which predetermined portions of an upper cover and a lower body of a straight section may serve as a coupling unit having elasticity and at least one bending section is formed on an upper surface of the multipurpose color duct so as to reinforce the strength of the multipurpose color duct, so that installation work and maintenance/ repair work for the cable tray system or the raceway system can be facilitated.

[23] Still yet another object of the present invention is to provide a multipurpose color duct made of aluminum, in which the multipurpose color duct is powder-painted with various colors so that an external appearance of the product can be improved while preventing environmental pollution caused by the plating process. Technical Solution

[24] In order to accomplish the above objects, the present invention provides a multipurpose color duct made of aluminum and adaptable for a cable tray system or a raceway system (cable duct system) for supporting cables by combining a straight section with other accessory parts, the color cable tray system, the multipurpose color duct comprising: an upper cover having a "D" shaped structure, being provided at both side ends thereof with "b" shaped protrusions and being formed on an upper surface thereof with at least one bending section for reinforcing tensile strength and load strength of the upper cover; and a lower body having a "D" shaped structure corresponding to the upper cover, being provided at both side ends thereof with "s" shaped coupling sections and being formed on a bottom surface thereof with at least one bending section for reinforcing tensile strength and load strength of the lower body, wherein the "b" shaped protrusions of the upper cover are fixedly coupled with the "s" shaped coupling sections of the lower body.

[25] According to the exemplary embodiment of the present invention, the multipurpose color duct further comprises an anti-deformation protrusion extending downward from both side ends of the bending section formed on the upper surface of the upper cover in order to reinforce the tensile strength and load strength of the multipurpose duct while preventing the multipurpose duct from being deformed beyond a predetermined degree. In addition, the upper cover and the lower body are fabricated through an extrusion process, respectively.

[26] Preferably, the upper cover and the lower body are powder-painted with various colors including red, blue and yellow after the upper cover and the lower body are fabricated through an extrusion process, respectively.

Advantageous Effects

[27] If the cable tray system or the raceway system is fabricated by using the multipurpose color duct according to the present invention, a separate coupling unit, such as a clamp, is not necessary because the coupling part is formed at the upper cover and the lower body of the straight section, respectively, so that installation work and maintenance/repair work for the cable tray system or the raceway system can be facilitated.

[28] In addition, if the cable tray system or the raceway system is fabricated by using the multipurpose color duct according to the present invention, since predetermined portions of the upper cover and the lower body of the straight section may serve as a coupling unit having elasticity, it is possible to facilitate installation work and maintenance/repair work for the cable tray system or the raceway system.

[29] Furthermore, if the cable tray system or the raceway system is fabricated by using the multipurpose color duct according to the present invention, since the multipurpose color duct is powder-painted with various colors, an external appearance of the product can be improved while preventing environmental pollution caused by the plating process. Brief Description of the Drawings

[30] FIG. 1 is a perspective view illustrating the structure of a cable tray system;

[31] FIG. 2 is a perspective view illustrating a ladder-shaped straight section of the cable tray system shown in FIG. 1 ;

[32] FIG. 3 is a perspective view illustrating a trough type straight section forming the cable tray system shown in FIG. 1 ;

[33] FIG. 4 is a perspective view illustrating an upper cover of the trough type straight section shown in FIG. 3;

[34] FIG. 5 is a perspective view illustrating a lower body of the trough type straight section shown in FIG. 3 according to one embodiment of the present invention;

[35] FIG. 6 is a perspective view illustrating a clamp used for fixing the trough type straight section shown in FIG. 3;

[36] FIG. 7 is a perspective view illustrating a lower body of the trough type straight section shown in FIG. 3 according to another embodiment of the present invention;

[37] FIG. 8 is a perspective view illustrating a lower body of the trough type straight section shown in FIG. 3 according to still another embodiment of the present invention;

[38] FIG. 9 is a perspective view illustrating the structure of a raceway system; [39] FIG. 10 is a perspective view illustrating a straight section of the raceway system shown in FIG. 9;

[40] FIG. 11 is a sectional view taken along line B-B of the straight section shown in

FIG. 10;

[41] FIG. 12 is an exploded perspective view illustrating a straight section of a multipurpose color duct made of aluminum according to one embodiment of the present invention;

[42] FIG. 13 is a perspective view illustrating a coupling state of the multipurpose color duct made of aluminum shown in FIG. 12;

[43] FIG. 14 is a sectional view taken along line A-A of the straight section of the multipurpose color duct made of aluminum shown in FIG. 12;

[44] FIG. 15 is a sectional view taken along line A-A of the multipurpose color duct made of aluminum shown in FIG. 13;

[45] FIG. 16 is an exploded perspective view illustrating a straight section of a multipurpose color duct made of aluminum according to another embodiment of the present invention; and

[46] FIG. 17 is a perspective view illustrating a coupling state of the multipurpose color duct made of aluminum shown in FIG. 16. Best Mode for Carrying Out the Invention

[47] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 12 to 15.

[48] FIG. 12 is an exploded perspective view illustrating a straight section of a multipurpose color duct made of aluminum according to one embodiment of the present invention, FIG. 13 is a perspective view illustrating a coupling state of the multipurpose color duct made of aluminum shown in FIG. 12, FIG. 14 is a sectional view taken along line A-A of the straight section of the multipurpose color duct made of aluminum shown in FIG. 12, and FIG. 15 is a sectional view taken along line A-A of the multipurpose color duct made of aluminum shown in FIG. 13.

[49] FIGS. 12 to 15 show the straight section 300 of a multipurpose color duct made of aluminum (hereinafter, simply referred to as a multipurpose duct) adaptable for a cable tray system, a raceway system, or a cable duct. Other parts of the system may have the structure identical to that of the straight section 300 and the straight section 300 can be modified into various parts having reinforced tensile force and load strength by bending or expanding the straight section 300, so the following description will be focused on the straight section 300.

[50] In other words, the cable tray system and the raceway system (cable duct system)

200 as shown in FIGS. 1 to 9 can be obtained by fabricating various parts while utilizing the straight section 300, which is a basic element of the multipurpose duct.

[51] Referring to FIG. 12, the straight section 300, which is the basic element of the multipurpose duct according to the present invention, includes a lower body 310 and an upper cover 320.

[52] As shown in FIGS. 12 to 15 in detail, the lower body 310 of the straight section 300 according to the present invention is bent in a "D" shape and the upper cover 320 is also bent in a "D" shape such that the upper cover 320 can be coupled with the lower body 310.

[53] It is preferred if the lower body 310 and the upper cover 320 are fabricated by extruding an aluminum alloy, such as Korean Standard A6061 or A6063, in view of the tensile strength and load strength.

[54] Herein, A6061 refers to an aluminum alloy consisting of Si (less than 0.40 to

0.80%), Fe (less than 0.7%), Cu (0.15 to 0.40%), Mn (less than 0.15%), Mg (0.8 to 1.2%), Cr (0.04 to 0.35%), Zn (less than 0.25%), Ti (less than 0.15%), and Al. In addition, A6063 refers to an aluminum alloy consisting of Si (less than 0.20 to 0.60%), Fe (less than 0.35%), Cu (less than 0.01%), Mn (less than 0.01%), Mg (0.45 to 0.9%), Cr (less than 0.10%), Zn (less than 0.10%), Ti (less than 0.10%), and Al.

[55] Referring to FIG. 12, the lower body 310 having the "D" shaped structure is provided at both ends thereof with a coupling section 317 having an "s" shape. A lateral side of the lower body 310 extending downward from the S-shaped coupling section 317 has a straight shape and at lest one bending section 315 is formed at the center of a bottom surface of the lower body 310. The bending section 315 is formed in order to reinforce the tensile strength and load strength of the straight section 300, that is, the multipurpose duct. Due to the bending section 315, the tensile strength and load strength of the multipurpose duct can be improved by 10 to 30%. In addition, the bending section 315 may reduce the contact area between the multipurpose duct and the floor or wall when the multipurpose duct is installed on the floor or wall, thereby allowing the multipurpose duct to be easily installed on the floor or wall. In addition, the bending section 315 may improve straightness (warpage prevention) characteristics of the multipurpose duct while preventing the multipurpose duct from being crooked when external impact is applied to the multipurpose duct.

[56] Herein, two to five bending sections 315 can be formed on the bottom surface of the multipurpose duct depending on the width of the bottom surface of the multipurpose duct. In addition, the bending section 315 can be formed at both lateral sides of the multipurpose duct. The size of the bending section 315 can be variously changed depending on applications thereof.

[57] As shown in FIG. 15, the S-shaped coupling section 317 formed at both ends of the lower body 310 may form a coupling unit 330 of the multipurpose duct together with a b-shaped protrusion 327 formed at both ends of the upper cover 320.

[58] The upper cover 320 also has the "D" shaped structure corresponding to the lower body 310 and is provided at both side ends thereof with the b-shaped protrusion 327. In addition, as can be understood from FIGS. 12 and 14, at least one bending section 325 is formed on an upper surface of the upper cover so as to reinforce the tensile strength and load strength of the upper cover 320. The function of the bending section 325 is identical to that of the bending section 315 formed on the lower body 310.

[59] Anti-deformation protrusions 329 downwardly extend from both side ends of the bending section 325 of the upper cover 320. The anti-deformation protrusions 329 not only prevent the S-shaped coupling section 317 formed at both side ends of the lower body from being deformed beyond a predetermined degree, but also improve the tensile strength and load strength of the upper cover 320.

[60] The multipurpose duct having the above structure can be obtained by extruding an aluminum alloy. The extrusion process will be described in detail with reference to FIG. 5.

[61] Since the upper cover 320 is bent in the "D" shaped structure while forming the b- shaped protrusions 327 at both ends thereof and the lower body 310 is bent in the "D" shaped structure while forming the S-shaped coupling sections 317 at both ends thereof, as shown in FIGS. 13 and 15, the b-shaped protrusions 327 of the upper cover 320 is coupled with the S-shaped coupling sections 317 of the lower body 310, thereby forming the coupling unit 330 for the multipurpose duct. That is, after matching the upper cover 320 with the lower body 310, if the worker slightly pushes the upper cover 320 against the lower body 310, the b-shaped protrusions 327 of the upper cover 320 is coupled with the S-shaped coupling sections 317 of the lower body 310. When the b- shaped protrusions 327 of the upper cover 320 is coupled with the S-shaped coupling sections 317 of the lower body 310 or when excessive force is applied to the upper cover 320 from the exterior, the lateral sides of the lower body 310 having predetermined elasticity and the S-shaped coupling sections 317 formed at upper portions of the lateral sides of the lower body 310 may be warped without being restored to their original shapes. In order to prevent such excessive force from being applied to the lower body 310 and the upper cover 320, the anti-deformation protrusions 329 downwardly extend from both side ends of the bending section 325 of the upper cover 320. As mentioned above, the anti-deformation protrusions 329 prevent the S-shaped coupling section 317 of the lower body 310 from being deformed beyond a predetermined degree when the excessive force is applied to the upper cover 320.

[62] Due to the coupling unit 330 for the multipurpose duct, the conventional clamp used for fixing the upper cover to the lower body is not necessary, so that the manufacturing cost for the multipurpose duct can be reduced and workability can be sig- nificantly improved when performing installation work and maintenance/repair work for the cable tray system or the raceway system.

[63] It is important that the b-shaped protrusions 327 of the upper cover 320 and the S- shaped coupling sections 317 of the lower body 310 must have predetermined elasticity. This is because the upper cover of the multipurpose duct according to the present invention is not simply put on the lower body, but must be coupled with the lower body as shown in FIGS. 1 and 9. That is, this is because the b-shaped protrusions 327 of the upper cover 320 must be coupled with the S-shaped coupling sections 317 of the lower body 310 without employing the clamp used for fixing the upper cover to the lower body.

[64] Therefore, if the multipurpose duct is fabricated by using the straight section 300 as shown in FIG. 12, an additional coupling member, such as a conventional clamp, is not necessary. Accordingly, it is possible to significantly reduce working time when performing installation work and maintenance/repair work for the cable tray system or the raceway system having the above structure.

[65] The coupling state between the upper cover 320 and the lower body 310 by means of the coupling unit 330 can be easily understood with reference to FIGS. 13 and 15.

[66] Since the cable tray system or the raceway system having the above structure is provided at the upper cover and the lower body thereof with the coupling unit, the conventional clamp is not necessary. Accordingly, installation work and maintenance/ repair work for the cable tray system or the raceway system having the above structure can be rapidly and effectively carried out.

[67] The multipurpose duct having the above structure according to the present invention can be powder-painted with various colors including red, blue, yellow, etc. after the extrusion process for the multipurpose duct has been completed. Powder-painting work is necessary in order to distinguish the multipurpose ducts according to the type of cables accommodated in the multipurpose ducts, such as a high voltage cable, a low voltage cable, a communication cable and a control cable. For instance, the high voltage cable is accommodated in a red duct, the low voltage cable is accommodated in a blue duct, and the communication cable is accommodated in a yellow duct. In this case, installation work and maintenance/repair work for the cable tray system or the raceway system can be facilitated. In addition, when the multipurpose ducts painted with various colors are exposed to the exterior, they may serve as external decoration, so it is possible to improve an aesthetic appearance of the cable tray system or the raceway system by selectively using the multipurpose ducts painted with various colors. Mode for the Invention [68] FIGS. 16 and 17 show a multipurpose color duct made of aluminum according to another embodiment of the present invention, which is modified from the multipurpose color duct shown in FIGS. 12 to 15. The multipurpose color duct according to another embodiment of the present invention has the structure identical to that of the multipurpose color duct shown in FIGS. 12 to 15, except that perforation holes 340 are formed at a bottom surface of the lower body 310 and an upper surface of the upper cover 320.

[69] Referring to FIGS. 16 and 17, the multipurpose color duct according to another embodiment of the present invention includes a plurality of perforation holes 340, which are spaced apart from each other lengthwise along the multipurpose color duct with a predetermined interval and a predetermined size. The perforation holes 340 allow the worker to easily check the type of cables accommodated in the multipurpose color duct from the outside of the multipurpose color duct. In addition, the weight of the multipurpose color duct can be reduced due to the perforation holes 340.

[70] Herein, the present invention does not limit the number and size of the perforation holes 340 formed in the upper cover and the lower body of the multipurpose duct. In addition, the perforation holes 340 can be formed widthwise along the multipurpose duct with various sizes and intervals. Industrial Applicability

[71] As can be seen from the foregoing, the multipurpose color duct made of aluminum according to the present invention can be used for the cable tray system, the raceway system or the cable duct system.

[72] In addition, when the cable tray system or the raceway system is constructed by using the multipurpose duct according to the present invention, since the coupling unit is formed at the lower body and the upper cover of the straight section, an additional fixing unit, such as the conventional clamp, is not necessary and installation work and maintenance/repair work for the cable tray system or the raceway system can be facilitated.

[73] Furthermore, if the cable tray system or the raceway system is fabricated by using the multipurpose color duct according to the present invention, since the multipurpose color duct is powder-painted with various colors, an external appearance of the product can be improved while preventing environmental pollution caused by the plating process.

Claims

[1] A multipurpose color duct made of aluminum and adaptable for a cable tray system or a raceway system (cable duct system) for supporting cables by combining a straight section with other accessory parts, the color cable tray system, the multipurpose color duct comprising: an upper cover having a "D" shaped structure, being provided at both side ends thereof with "b" shaped protrusions and being formed on an upper surface thereof with at least one bending section for reinforcing tensile strength and load strength of the upper cover; and a lower body having a "D" shaped structure corresponding to the upper cover, being provided at both side ends thereof with "s" shaped coupling sections and being formed on a bottom surface thereof with at least one bending section for reinforcing tensile strength and load strength of the lower body, wherein the "b" shaped protrusions of the upper cover are fixedly coupled with the "s" shaped coupling sections of the lower body.

[2] The multipurpose color duct as claimed in claim 1, further comprising an anti- deformation protrusion extending downward from both side ends of the bending section formed on the upper surface of the upper cover in order to reinforce the tensile strength and load strength of the multipurpose duct while preventing the multipurpose duct from being deformed beyond a predetermined degree.

[3] The multipurpose color duct as claimed in claim 1, wherein the upper cover and the lower body are fabricated through an extrusion process, respectively.

[4] The multipurpose color duct as claimed in claim 1, wherein the upper cover and the lower body are powder-painted with various colors including red, blue and yellow after the upper cover and the lower body are fabricated through an extrusion process, respectively.