Abstract:
An artificial tree has a lightweight plastic base that may be filled with water or sand to make it heavy enough to support the tree in an outdoor environment without the use of guywires. A sectional vertical support member permits the assembler to vary the height of the assembled tree with ease. A light string is alternately routed up and down between the base and the top of the tree and around the base to give the assembled tree a conical shape that simulates a decorated Christmas tree when lit.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to the field of artificial trees and especially artificial Christmas trees.  
         BRIEF DESCRIPTION OF THE PRIOR ART  
         [0002]    Artificial Christmas trees have great popularity for a number of significant reasons, including low cost, reusability, and ease of assembly, disassembly and storage. Many types of artificial Christmas trees are well known in the prior art. One class of artificial Christmas tree design is constructed to simulate the appearance of a natural tree. An example of such a tree is illustrated in U.S. Pat. No. 5,652,032 to Kaczor et al., in which branches simulating the branches of a real tree are inserted into a vertical support. Other prior art artificial Christmas trees use lights to outline the generally conical shape of a natural tree without attempting to simulate the appearance of the tree itself. U.S. Pat. No. 5,094,893 to Snider illustrates an example of this type of tree, which is most effectively viewed at night and from a distance.  
           [0003]    Trees of the latter type are commonly used in outdoor settings where wind and other forces make stability a particular concern. Such artificial trees routinely employ elaborate guywire systems with large numbers of wires of precise length and multiple stakes to steady the tree and hold it upright. In addition to complicating the assembly and disassembly process, the elaborate guying system usually employs a large number of parts that may be lost, and thus diminish the reusability of the tree.  
           [0004]    It is desirable to have an artificial Christmas tree that presents an attractive appearance in an outdoor setting when lighted and which is easily assembled from lightweight materials, yet which is strong and stable enough to withstand wind and other forces without complicated guying systems. It is even more desirable for such a tree to be variable in height to provide greater flexibility in decorating a scene.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides an improved artificial tree that overcomes the above-identified disadvantages of the prior. In particular, an artificial tree is provided that may be incrementally adjusted in height and is stable under outdoor conditions without the use of guywires. A base and cap provide protrusions between which a light string may be secured alternately from base to cap. A vertical support member extends from the base and supports the cap above the ground, the vertical support member having a number of sections that may be increased or decreased according to the desired height of the tree. Each light string has a female electrical plug at one end and a male plug at the other to permit multiple strings of light to be connected together in a conventional manner. An artificial tree as described is easy to assemble and disassemble, lightweight and compact for easy storage, and is strong enough when assembled to be usable outdoors as well as indoors. A method for assembling a tree as described above is also provided.  
           [0006]    An artificial tree according to the invention includes a base of generally cylindrical shape having a top, a bottom, and a substantially hollow interior, the top having a port for permitting access to the interior, and a center. A vertical support member extends upwardly from the center of the base, and a circular cap is positioned atop the support member. A plurality of light string segments extend between the circumference of the base and the cap.  
           [0007]    A structural frame for an artificial tree includes a base of generally cylindrical shape having a top, a bottom, and a substantially hollow interior. The top has a port for permitting access to the interior and a center. A vertical support member extends upwardly from the center of the base. A circular cap is positioned atop the support member.  
           [0008]    A method of constructing an artificial tree includes the steps of securing a vertical support member to a base, affixing a cap to the top of the vertical support member, affixing a first end of a light string to a first slot and extending the light string upwardly to the cap and downwardly to the first slot, routing the string under the lip to the adjacent slot, and repeatedly extending the string upwardly to the cap and downwardly back to the same slot until the string extends downwardly to the last slot adjacent to the first slot. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in light of the accompanying drawings, in which:  
         [0010]    [0010]FIG. 1 is a perspective view of a partially assembled artificial tree according to the invention;  
         [0011]    [0011]FIG. 2 is an exploded elevation view of the base, support and cap of the embodiment of FIG. 1;  
         [0012]    [0012]FIG. 3 is a top view of the base according to the invention;  
         [0013]    [0013]FIG. 4 if a top view of the cap according to the invention;  
         [0014]    [0014]FIG. 5 is a detail view of a string of lights ready to be secured to the base of FIG. 1;  
         [0015]    [0015]FIG. 6 is an elevation view of a portion of the base of FIGS. 1 and 3; and  
         [0016]    [0016]FIG. 7 is a perspective view of a stake for securing the base of FIGS. 1 and 3 to the ground. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    Referring to FIG. 1, an artificial tree such as a Christmas tree  12  includes a base  14  having a generally cylindrical shape, a sectional support member  16 , and a cap  18 . The sectional support member  16  is secured to the center of the base  14  and extends vertically above the base  14 . The cap  18  is positioned atop and secured to the support member  16 . The length of support member  16  determines the height of the fully assembled tree. A decorative light string  20  runs alternately between and the base and the cap as will be described in greater detail below. Three holes  22  are positioned approximately equidistantly and extend through the base  14 , in order to provide a way to secure the base to the ground with stakes, as described in more detail below. The base  14  is preferably hollow, to permit insertion of sand, water, or a similar heavy material, thereby weighting the base to provide further support and resistance to tipping of the tree from wind or other forces. A port  58  permits access to the hollow interior for the insertion of the weighting material. Addition of such material will reduce the likelihood of the tree being blown over by wind or knocked over by other forces.  
         [0018]    [0018]FIG. 2 provides a more detailed view of the base  14 , support member  16 , and cap  18  prior to assembly. In the illustrated embodiment, a threaded socket  24  is provided on the top and at the center of the base  14 . A first section  16   a  of support member  16  has a threaded lower end  26  that may be screwed into the threaded socket  24  in the base  14 . The upper end of section  16   a  has a threaded socket  28 . A second section  16   b  of the support member is constructed identically to section  16   a  and has a threaded lower end  30  and a threaded socket  32  at its upper end. Additional sections may be added to further increase the length of the section  16  and thereby increase the overall height of the assembled tree. By varying the number of sections, the height of the tree may be easily adjusted to create a pleasing effect for the location at which it is erected. A cap  18  includes a threaded protrusion  34  that is screwed into the threaded socket  32  of section  16   b  or the topmost section if additional sections are present. In a preferred embodiment, each section  16   a ,  16   b , etc. is approximately 2 feet long. The addition of additional sections permits assembly of a tree that varies in height, e.g., 4′, 6′, 8′, or taller at the discretion of the assembler.  
         [0019]    It will be obvious to one skilled in the art that the use of threads to make the described connections is but one of many well-known methods that may be used. For example, the lower support member  16   a  may be inserted directly into a hole in the base and the cap protrusion  34  may be inserted directly into an unthreaded socket  32  of support member  16   b . By manufacturing the pieces to close tolerances, they can be made to fit tightly to make a wedge connection more secure. Similarly, adjacent sections of the support member  16  may be connected by constructing them of two diameters, a portion of the member having a smaller diameter being designed to fit securely into a portion of the adjacent member having a larger diameter.  
         [0020]    Bases  14  of different diameters may be provided depending on the desired height of the tree. A base of around 3 feet in diameter for example is suitable for an 8 foot tree.  
         [0021]    Referring to FIGS. 3 and 6, the base  14  is preferably constructed of a strong but lightweight material such as synthetic ABS plastic, and has a top  35  and a bottom  37 . A plurality of slots  36  are equally spaced around the circumference of the base. Each slot extends vertically downwardly from the top  35  of the base  14  through a lip  38  that extends outwardly from the circumference of the base. Within each slot  36  is an elongated section  40  that makes the interior of slot  36  wider than its exterior and has a generally T-shape. As is explained more fully below, the slots  36  receive light string segments  22  that extend between the circumference of the base and the cap.  
         [0022]    [0022]FIG. 4 illustrates a top view of an embodiment of a cap  18  having a plurality of indented segments  44  around its periphery. Between each indented segment  44  is a protruding segment  46  having an upwardly extending lip  48 .  
         [0023]    Light string segments  20  may each be a separate light string, but in a preferred embodiment, each segment will be a part of a single light string. The single string may be a plurality of conventional Christmas tree light strings connected in series. In a preferred embodiment, a single light string is connected to the base at an arbitrary first slot  36   b  (FIG. 3) that, for purposes of description, will be called the origination point. The string then extends upwardly to the cap and loops downwardly back to the next slot  36   c . The string continues under the lip  38  to the next slot  36   d  and then upwardly to the cap. The light string again loops over the cap and downwardly to slot  36   e . The light string continues in this manner around the circumference of base  14  until it reaches a termination point when it reaches slot  36   a  after extending downward from cap  18 .  
         [0024]    [0024]FIGS. 5 and 6 illustrate how the light string is secured to the base at slots  36   a  and  36   b . An elastic band  50  has two loops  52   a  and  52   b . The band  50  is constructed to fit securely between the two adjacent slots  36   a  and  36   b  of base  14 . Only one band  50  is required for tree assembly. A first hook  54   a , or similar attachment device, connects one end of the light string  20  to the loop  52   a . A rubber sleeve  56  is preferably installed on light string  20  and has a hook  54   b  which is attached to loop  52   b . Pulling the light string  20  through the sleeve when it is hooked to the loop  52   b  tensions the string.  
         [0025]    The method of assembling the artificial tree begins by screwing a first sectional support member  16   a  into socket  24  of base  14 . A second (and third, fourth, etc.) sectional support member is screwed together with the first member depending upon the desired height of the finished tree. For example, three two-foot sectional support members would be screwed together for a six foot tree and four sectional support members would be screwed together for an eight foot tree. The cap  18  is screwed onto the topmost sectional support member to complete the basic support structure of the tree. The lights string is then attached to the base and support as set forth above to define the shape of the tree.  
         [0026]    Christmas light strings are well known in the art and a wide variety of colors, sizes and models may be used advantageously with the support structure described above. Such strings come in varying lengths and may be connected end-to-end to make longer strings. Assembly of the tree does not require a specific length of light string, and the length selected need not be predetermined according to the height of the tree.  
         [0027]    While the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those of ordinary skill in the art that various changes and modifications may be made without deviating from the inventive concepts set forth above.