Abstract:
A flexible irrigation pipe including porous and non-porous segments combined together to avoid unnecessary water loss and improve water distribution along the porous segments of the irrigation pipe.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The population growth combined with lack of rainfall creates water scarcity in many regions of the country and the world. Lack of water supply leads to water rationing in many areas of the country. To use water resources more efficiently, large number of households use flexible porous irrigation pipes, commonly known as ‘soaker hoses’, to supply water to the plants and prevent damage to house foundations. 
         [0002]    However, a conventional ‘soaker hose’ irrigation device such as one disclosed in U.S. Pat. No. 4,168,799, while useful, has considerable disadvantages. A typical household water source is placed two to three feet above the ground. The necessary elevation of the initial segment of the porous pipe above the irrigation plane causes water exiting the porous pipe in the elevated segment to flow down along the outside wall of the pipe to the area where the porous pipe comes in contact with the ground. This irrigation pipe configuration, combined with the higher water velocity and pressure at the water source, results in significant over-watering in the area closest to the water source and a waste of valuable resource. In addition, less water is supplied to the far end of the conventional porous pipe, reducing the effectiveness of the conventional irrigation device. 
         [0003]    Another negative consequence of the over-watering due to inefficient design of a conventional ‘soaker hose’ is possible damage to the foundation. The excessive supply of water close to the water source flows under the foundation, eroding the surrounding soil. The resulting water accumulation potentially creates cavities around and under the foundation. This process, over time, may lead to cracks and sinking of the foundation. 
         [0004]    An alternative approach to solve the water loss problem has been disclosed in U.S. Pat. No. 4,615,642. The porous pipe having a porosity which varies continuously and controllably with length is designed to regulate water distribution over long distances. However, this device does not have any non-porous segments and does not efficiently address the water loss that occurs in the porous pipe in the segment closest to the water source when the water source placed above the irrigation plane. Another disadvantage of this device is due to common practice of connecting multiple soaker hoses in series to extend over a longer distance. A device that has variable porosity is not suitable for this common application. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention discloses a flexible irrigation pipe comprised of porous and non-porous segments, so that excessive leakage in the segment closest to an elevated water source is prevented. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic view of a conventional ‘soaker hose’ irrigation device 
           [0007]      FIG. 2  is a schematic view of a flexible irrigation pipe comprised of porous and non-porous segments 
           [0008]      FIG. 3  is a schematic view of a cross-section of the pipe according to the first embodiment 
           [0009]      FIG. 4  is a schematic view of a cross-section of the pipe according to the second embodiment 
           [0010]      FIG. 5  is a schematic view of a cross-section of the pipe according to the third embodiment 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]      FIG. 1  is a diagram illustrating a conventional ‘soaker hose’ irrigation device, comprising of one porous segment  3 . The porous segment  3  is typically connected to a water source coupling  4  which allows the irrigation device to be connected to a water source  5 . The other end of the porous segment  3  is typically connected to an end coupling  6  which, in the simplest configuration of the irrigation device, is closed off by a cap  7 ; it can also be connected to the water source coupling  4  of an additional compatible irrigation device or a chain of additional irrigation devices. 
         [0012]    The present invention is best illustrated with reference to accompanying drawings in which  FIG. 2  shows the general schematic view of the present invention and  FIG. 3 ,  4 , and  5  illustrate cross-sections of the preferred embodiments. 
         [0013]    Reference is now made to  FIG. 2 . A flexible irrigation device disclosed in the present invention includes a non-porous segment  1  and porous segment  3  where the non-porous segment  1  is placed in the location closest to the water source  5 . 
         [0014]    The nature of the connection between the porous segment  3  and non-porous segment  1  will be further illustrated in the description of the various preferred embodiments below. One end of the non-porous segment  1  is connected to a water source coupling  4  which allows the irrigation device to be connected to a water source  5 . One end of porous segment  3  is connected to an end coupling  6  which, in the simplest configuration of the irrigation device, is closed off by a cap  7 ; it can also be connected to the water source coupling  4  of an additional compatible irrigation device such as a conventional ‘soaker hose’ irrigation device or a chain of additional irrigation devices. 
         [0015]    Reference is now made to  FIG. 3 . In this first of the preferred embodiments the non-porous segment  1  includes two layers; an outer layer hose  8  made of non-porous material and an inner layer hose  9  made of porous material. The length of the non-porous segment  1  is determined by the length of the outer layer hose  8 . The outer layer hose  8  and the inner layer hose  9  overlap across the complete length of the non-porous segment  1 . The outer non-porous layer hose  8  and the inner porous layer hose  9  are permanently and flexibly bonded together by a bonding layer  2  to form the non-porous segment  1 . The inner layer hose  9  is a continuous porous hose which spans from a water source coupling  4  to the end coupling  6 . The length of the porous hose  9  is typically between 40 and 100 feet long while the length the non-porous layer hose  8  is optimally 2 to 6 feet long. The portion of the porous hose  9  not enclosed in the outer layer hose  8  forms the porous segment  3 . 
         [0016]    Reference is now made to  FIG. 4 . In this second of the preferred embodiments a portion of the non-porous segment  1  includes two layers: the outer layer hose  8  made of non-porous material and the inner layer hose  9  made of porous material. The remaining portion of the non-porous segment  1  includes one layer of the aforementioned non-porous hose  8 . The length of the non-porous segment  1  is determined by the length of the outer layer hose  8 . The outer non-porous layer hose  8  and inner porous layer hose  9  are, where overlapping, permanently and flexibly bonded together by a bonding layer  2 . The inner layer hose  9  is a continuous porous hose which spans from one end  10  located inside the outer layer hose  8  to the end coupling  6 . The length of the porous hose  9  is typically between 40 and 100 feet long while the length of the non-porous layer hose  8  is optimally 2 to 6 feet long. The portion of the porous hose  9  not enclosed in the outer layer hose  8  forms the porous segment  3 . 
         [0017]    Reference is now made to  FIG. 5 . In this third of the preferred embodiments the non-porous segment  1  includes a porous hose  9  and a penetrating sealing agent  11  applied directly to the porous hose  9 . The length of the porous hose  9  is typically between 40 and 100 feet long while the length the non-porous segment  1  is optimally 2 to 6 feet long. The portion of the porous hose  9  where the penetrating sealing agent  11  is not applied forms the porous segment  3 . 
         [0018]    Although the preferred embodiments of the apparatus of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description of the Invention, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.