Abstract:
A pole which is designed to be inserted into the ground, the pole having a lower tapered segment at one end thereof, the lowered tapered segment having double helical threads thereon, and an upper segment upon which objects may be supported.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a pole designed to be inserted into the ground and more particularly, relates to a pole insertable into the soil and which may support other objects. 
       BACKGROUND OF THE INVENTION 
       [0002]    The use of poles which are insertable into the soil is well known in the art. Such poles typically have a screwthread formed at one end thereof and are inserted into the soil or ground by applying a rotational torque to the pole. Typically, the rotational torque is imparted by means of a horizontal lever which will engage with the vertical pole and a force being applied to the horizontal member. 
         [0003]    The pole is typically utilized to support a further object. The further object may be something which is placed on the pole or alternatively, the pole may form a series of members which are interconnected in one manner or another to form a structure such as a fence. 
         [0004]    A problem which arises with such poles is their inability to resist horizontal or other forces applied to the pole. Typically, the engagement of the threaded portion with the soil is not sufficient to overcome such forces and as a result, the pole either leans to one side or falls over. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the present invention to provide a pole which is insertable into the soil and which pole has a substantial resistance to horizontal or other forces applied thereto. 
         [0006]    According to one aspect of the present invention, there is provided a pole designed to be inserted into the ground, the pole having a lower tapered segment at one end thereof, the lower tapered segment having double helical threads thereon, and an upper segment. 
         [0007]    In a preferred embodiment, the double helical threads are arranged such that a first one of the threads extends outwardly for a first distance while a second one of the threads extends outwardly a second distance, the first distance being larger than the second distance. This arrangement is advantageous in that the first thread which extends outwardly a greater distance will tend to compact the soil between adjacent threads. The second helical thread, which extends outwardly a lesser distance, will then tend to bite into the compact soil and reinforce the grip thereon. The depth or height of the threads can vary as is known to those skilled in the art. Typically, the first helical thread would extend outwardly by a distance equal to between 5.0 mm and 7.5 mm while the second helical thread would preferably extend outwardly by a distance between 2.5 mm and 4.0 mm. In a preferred arrangement, the ratio between the depth of thread between the first helical thread and the second helical thread would be 2:1. 
         [0008]    The use of the different sized threads also provides for a smoother action and prevents what could be referred to as cavitation in the soil. 
         [0009]    In one embodiment, the pole has the aforementioned upper segment and the lower threaded segment. Intermediate the upper and lower segments is an intermediate segment also having a tapered configuration. In this embodiment, the intermediate segment would taper inwardly from the point of joinder with the upper segment through the lower threaded segment. This arrangement provides for the intermediate segment to help in compaction of the soil and to ensure that the soil remains compacted. 
         [0010]    The thread form may be of any convenient shape including, among others, square, triangular, trapezoidal, etc. In a preferred embodiment, the thread form employed in the present invention is triangular and more particularly, is based on an isosceles triangle. The screwthread may be truncated with preferably the second helical thread being somewhat more truncated than the first thread. 
         [0011]    The thread angle may be any suitable as is clearly established in the art. The lead in a typical arrangement would be between 1 and 4 cm. 
         [0012]    In a preferred embodiment, the pole has an upper segment which is cylindrical in configuration and a lower segment which is of a tapered configuration. 
         [0013]    The pole may be formed of any suitable material including, for example, metallic materials, reinforced plastic materials, etc. Such suitable materials are well known to those knowledgeable in the art and need not be discussed further herein. 
         [0014]    The sizing of the pole can vary depending upon the required end use and the type of soil into which the pole is to be inserted. Again, it suffices to say that one skilled in the art could determine the required size. 
         [0015]    The pole of the present invention may be used for many different purposes. Preferred embodiments would include the use of other objects placed thereon, such objects being things like planters, bird feeders, etc. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Having thus generally described the invention, reference will be made to the accompanying drawings illustrating an embodiment thereof, in which: 
           [0017]      FIG. 1  is a perspective view of a screwthreaded pole according to an embodiment of the present invention; 
           [0018]      FIG. 2  is a perspective view of a screwthreaded pole according to the prior art; 
           [0019]      FIG. 3  is a cross-sectional view illustrating the pole of  FIG. 2  and the immediate environment when the pole has been inserted into the soil; 
           [0020]      FIG. 4  is a view similar to  FIG. 2  showing the total environment of the pole of  FIG. 2  after insertion in soil; 
           [0021]      FIG. 5  is a cross-sectional view of the screwthreaded pole of  FIG. 1  and the immediate environment after insertion into the soil; 
           [0022]      FIG. 6  is a view illustrating the screwthreaded pole of  FIG. 4  and the total environment surrounding the pole after insertion in soil; 
           [0023]      FIG. 7  is a cross-sectional view of a bottom portion of a screwthreaded pole and the immediate environment after insertion into soil; and 
           [0024]      FIG. 8  is a view of the pole of  FIG. 7  and the total environment surrounding the pole after insertion in the soil. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Referring to the drawings in greater detail and by reference characters thereto, there is illustrated in  FIGS. 2 to 4  a prior art threaded pole. In this embodiment, the threaded pole is generally designated by reference numeral  30  and includes a constant diameter pole  32  having a helical screwthread  34  extending about a portion of pole  32 . The lower end  35  of screwthread  34  may be formed downwardly of pole  32  to provide a means of engaging the earth initially. 
         [0026]      FIG. 3  shows pole  32  after engagement with the soil. The soil is designated by reference numeral  36  and comprises “disturbed soil” which is relatively loose after being disturbed by the insertion of pole  32 . 
         [0027]    As shown in  FIG. 4 , the disturbed earth  36  extends about pole  32  while undisturbed soil  38  surrounds the disturbed soil  36 . 
         [0028]    The screwthreaded pole of the present invention is illustrated in  FIGS. 1, 5 and 6  and will now be referred to. 
         [0029]    The screwthreaded pole is generally designated by reference numeral  10  and includes a cylindrical upper pole  12  and a tapered lower portion generally designated by reference numeral  14 . 
         [0030]    Upper pole  12  is of a conventional structure and is preferably of a cylindrical configuration. Pole  12  may be comprised of several different portions secured together. An aperture  22  extends through the side wall of pole  12 . 
         [0031]    Lower tapered portion  14  is provided with a first helical thread  18  which extends outwardly from the body. A second helical thread  20  is provided intermediate first helical thread  18  and also extends outwardly from the body. It will be noted that thread  18  extends outwardly a greater distance than helical thread  20 . 
         [0032]    Upon insertion in the soil, and as may be seen in  FIGS. 5 and 6 , an area of disturbed earth  24  extends about the lower portion tapered section  14 . About this disturbed earth, there is provided a semi-compacted area of earth  26  which is less disturbed than portion  24 . 
         [0033]    Finally, there is provided a highly compacted portion of earth  28  which has indentations  29  from screwthread  18  therein. This highly compacted earth portion  28  provides a firm support for pole  12 . 
         [0034]    As shown in  FIG. 6 , remaining undisturbed earth  38  surrounds the portions previously described. 
         [0035]    In the embodiment of  FIGS. 7 and 8 , similar reference numerals are employed as in the previously described embodiment for common components. In the arrangement shown in  FIGS. 7 and 8 , intermediate the lower tapered portion and the pole itself, there is provided a tapered section generally designated by reference numeral  25 . This tapered section extends between the threaded portion and the cylindrical portion and an intermediate segment  25  tapers inwardly from the point of joinder with the upper segment through the lower threaded segment. This intermediate segment  25  provides help in compaction of the soil and to ensure that the soil remains compacted. 
         [0036]    It will be understood that the above described embodiment is for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.