You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to skylights and more particularly to tubular skylights, which include a reflective tube extending downwardly from the dome.  
           [0002]    Tubular skylights have acquired increasing popularity as a means of introducing natural light into the interior of a building. These skylights include a curb mounted on the roof of a building, a dome mounted on the curb, and a reflective tube secured within the curb. The reflective tube extends between the curb and a light diffuser within the building&#39;s ceiling. The natural light entering the skylight through the dome reflects downwardly through the tube to the diffuser. The tube in a sense acts as a gigantic optical fiber. Typically both the curb and the tube are fabricated of aluminum.  
           [0003]    The efficiency and type of light reflected from the dome to the diffuser depends in part on the reflective tubing. The manufacturer, shipper, and installer have to be careful not to bend or deform the reflective metal tube or the metal roof flashing. Any deformation may cause degradation in the efficiency of the skylight. A deformation near one of the ends of the tube may impair proper attachment of the tube to either the roof flashing or the diffuser assembly.  
           [0004]    The installation of the tubular skylight can be time consuming. First, great care has to be taken during shipment and installation to prevent any distortion in the metal pieces. Second, the reflective tube must be inserted through a hole in the roof and carefully connected to the curb.  
           [0005]    Another problem is the inability to choose the desired type of light when the skylight is installed. Typically skylights are made as bright as possible by highly polishing the aluminum tubing. If a less harsh light is desired, the only way this can be accomplished is through the installation of a less translucent diffuser.  
         SUMMARY OF THE INVENTION  
         [0006]    The aforementioned problems are overcome in the present invention wherein a tubular skylight includes a curb having an integral reflective tube section. The integral curb/tube facilitates installation and eliminates the need to attach and seal two components. The curb/tube also reduces the number of pieces and eliminates an attachment point.  
           [0007]    In the preferred embodiment, the tube is molded of plastic and includes a metalized reflective coating on the tube section. When fabricated of plastic, the curb/tube is less likely to be bent or deformed during shipment and installation. A curb/tube without any deformation provides a better seal with the roof and subsequent tube sections. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a perspective view showing a tubular skylight having the roof flashing of the present invention mounted within a building.  
         [0009]    [0009]FIG. 2 is an exploded perspective view of the tubular skylight;  
         [0010]    [0010]FIG. 3 is a top plan view of the curb/tube;  
         [0011]    [0011]FIG. 4 is a bottom plan view of the curb/tube;  
         [0012]    [0012]FIG. 5 is a sectional view of the curb/tube taken along line  5 - 5  in FIG. 3; and  
         [0013]    [0013]FIG. 6 is a sectional view of an alternative embodiment of the curb/tube.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]    I. Construction  
         [0015]    A tubular skylight constructed in accordance with the preferred embodiment of the invention is illustrated in FIGS. 1 and 2 and generally designated  10 . As perhaps most clearly illustrated in FIG. 2, the skylight includes a tube assembly  16  interconnecting a dome assembly  12  and a diffuser assembly  14 . The skylight is installed in a building B having a roof R and a ceiling C. More particularly the dome assembly  12  is mounted on a roof R and the diffuser assembly  14  within the ceiling C. The tube assembly  16  channels light between the dome assembly  12  and the diffuser assembly  14 . With the exception of the curb/tube  30  (as discussed below), the skylight  10  is generally well known to those skilled in the art.  
         [0016]    The diffuser assembly  14  includes a diffuser plate  74 , a trim ring  72  and ceiling screws  76 . The trim ring  72  is attached to the ceiling C by the use of the ceiling screws  76 . The diffuser plate  74  attaches over the trim ring  72 . The diffuser plate  74  can be a prismatic light diffuser, a less translucent light diffuser, or any other style based on personal preference or aesthetic choice.  
         [0017]    The tube assembly  16  interconnects the dome assembly  12  with the diffuser assembly  14 . Specifically the tube assembly  16  connects the curb/tube  30  to the trim ring  74 . The tube assembly  16  may include one or more tubes of which some may be flexible or angled. Flexible accordion tubes or bent tubes allow the diffuser assembly  14  to be offset from the curb/tube  30 . The tube assembly  16  may also come in a variety of lengths to accommodate different heights and locations between the roof R and the ceiling C.  
         [0018]    The dome assembly  12  includes a dome  20 , and a curb/tube  30 . The dome can have a variety of shapes and may be secured to the curb/tube by dome screws  22 , adhesive or any other means.  
         [0019]    The curb/tube  30  is most clearly illustrated in FIGS.  3 - 5  and includes a flashing  32 , an integral tube  36 , an outer wall  34  and ribs  48 . The flashing  32  rests on the roof R with the outer wall  34  extending upwardly to meet the integral tube  36  that passes through the center of the outer wall  34  and below the flashing  32 . The ribs  48  interconnect the integral tube  36  to the housing  34 .  
         [0020]    The flashing  32  of the curb/tube  30  may be constructed in almost any shape or size. The flashing may be substantially planar to lie on a flat roof R or in any other shape to fit a variety of roofs such as a tile roof. The flashing  32  is located between the upper and lower ends of the tube  36  so that a substantial portion of the tube  36  is on either side. In the preferred embodiment, as illustrated in FIGS. 1, 2, and  5 , the flashing is located about midway along the length of the tube  36 . The flashing  32  is attached to the roof R with a fastening means  44  such as screws or nails but other means such as adhesive may be readily used.  
         [0021]    The outer wall  34  includes a top lip  38 . The outer wall  34  protrudes upwardly from approximately the center of the flashing  32  to the top lip  38 . The outer wall  34  is generally tapered inwardly from the flashing  32  to the top lip  38 . It should be readily apparent that the outer wall  34  does not have to be tapered at all. The top lip  38  may be made in any shape such as a circle, a triangle, or an octagon to match the shape of the dome  20 . The dome  20  is sealed to and supported by the top lip  38 . As can be seen in FIG. 5, the flashing  32  may be angled in relation to the longitudinal axis of the outer wall  34 . This angle may vary to correspond with different slopes of the roof R. For ease of manufacture and inventory, this angle also may be limited to one or a few specified angles.  
         [0022]    The ribs  48  are integrally molded with the outer wall  34  and the tube  36  to maintain a proper spacing relationship and rigidity. The ribs  48  generally extend between the tube  36  and the outer wall  34 . In the preferred embodiments, these ribs  48  extend from the top lip to approximately the flashing  34 . The curb/tube  30  may easily be manufactured without these ribs  48 .  
         [0023]    The integral tube  36  includes a reflective inner surface  46 , an upper end means and a lower end means. In the preferred embodiment, the lower end means is a bottom edge  56  and the upper end means of the integral tube  36  joins the outer wall  34  to form the top lip  38 . The integral tube  36  extends downwardly from the top lip  38 , through approximately the center of the outer wall  34  and the flashing  32 . The integral tube  36  extends beyond the flashing  32  and terminates in the bottom edge  56 .  
         [0024]    The inner surface  46  may be coated with a reflective coating  46  to efficiently transfer light from the dome  20  downwardly to the diffuser assembly  14 . The reflective coating  46  may be made out of a bright metallic finish, a soft opaque white or any shade therebetween depending on the type of light desired. Other coatings may be applied depending on the desired optical effect.  
         [0025]    In an alternative embodiment, the curb/tube  30  may be made without the outer wall  34  and the ribs  48 , as illustrated in FIG. 6. Instead, the integral tube  36  includes a flashing  34  extending outwardly from the tube  36 . In some embodiments, the flashing  34  may also be angled in relation to the longitudinal axis of the tube  36  to correspond to varying roof angles.  
         [0026]    II. Manufacture  
         [0027]    The curb/tube  30  is generally molded as one piece with an integral tube  36 , outer wall  34 , flashing  32  and ribs  48 . The curb/tube  30  is preferably molded out of a plastic material. The application of the reflective coating  46  to the plastic curb/tube  30  is well known in the art.  
         [0028]    III. Installation  
         [0029]    The tubular skylight  10  is installed within the building B in the conventional fashion. Holes are cut into the roof R and in the ceiling C. The curb/tube  30  is installed on the roof R with the integral tube  36  extending through and below the roof R. The flashing  32  can be secured to the roof R with the use of fasteners  44  such as screws or nails, although adhesive or any other means may also be used to secure the flashing  32  to the roof R. In the preferred embodiment, the curb/tube  30  includes preformed holes  54  through which the fasteners  44  pass.  
         [0030]    The slope of the roof R generally determines the angle between the flashing  32  and the longitudinal axis of the integral tube  36 . Preferably this angle is such that the top lip  38  integrally connecting the outer wall  34  and tube  36  provides the best angle for sunlight to enter the dome  20  when the flashing  32  is installed on the roof R. The dome  20  is then mounted and sealed to the top lip  38  and outer wall  34 . The integral tube  34  extends beyond the flashing  32  so that the tube assembly  16  may be connected to the bottom edge  56 . The tube assembly  16  extends from the bottom edge  56  of the integral first tube section  36  to the trim ring  72  in the ceiling C.  
         [0031]    The above description is that of the preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.

Summary:
A tubular skylight having an improved one-piece curb/tube improving the ease of manufacture and installation. The one-piece tube/curb having a tube and a flashing integrally molded of plastic. The tube extends above the flashing to support a dome and below the flashing to connect to an adjacent light tube section. The tube preferably includes a reflective inner surface to enhance light conveyance.