Patent Publication Number: US-2006006643-A1

Title: Connector for landscape irrigation pipe and method of using the same

Description:
The present application is related to U.S. Provisional Patent Application Ser. No. 60/586,091, filed on Jul. 7, 2004, which is incorporated herein by reference and to which priority is claimed pursuant to 35 USC 119. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates to the field of water pipe fittings or connectors and, more particularly, to a connector body having an improved barb and landing design to improve the seal established between the connector and a tubing element.  
      2. Description of the Prior Art  
      Connectors are used daily in landscaping operations for joining flexible tubing, tube, and similar cylindrical members to each other. A typical connector comprises a rigid tubular body adapted to fit in the inner circumference of a free end of the flexible tubing. Such a connector often adopts barb members integrated on its outer circumference. These barb members are force fit into the flexible tubing and have sharp edges to assist in retaining the flexible tubing on the tubular connector. U.S. Pat. No. 3,711,130 to Betzler, U.S. Pat. No. 5,853,202 to Li et al., and U.S. Pat. No. 5,542,712 all disclose these or similar tubular connectors.  
      Conventional connectors are usually formed with integral barb members having sharp edges and no surface area to contact the inner surface of the flexible tubing. The barbs immediately connect the tubing, providing a seal, but provide limited surface from which secure gripping is attained.  
      Conventional connectors are not compatible with tubing at higher water pressures and temperatures in that a proper seal is not maintained. Furthermore, when thinner and/or softer tubes are used, traditional connectors cause failures at higher temperatures because of the increasing flexibility of the tubing. Conventional connectors have little to no locking capability, so the tubing connection often times leaks or can completely vacate the connector as heat and pressure escalate.  
     BRIEF SUMMARY OF THE INVENTION  
      Accordingly, it is an object of this invention to provide a connector for landscape irrigation pipe that can maintain a seal under higher temperatures and pressures. This invention also provides the art with a simple, inexpensive connector that overcomes the shortcomings of the prior art described above.  
      Generally, this invention provides a connector for use with irrigation tubing, providing a mechanical lock between the connector and the water tubing. The connector has a generally cylindrical body with an enlarged end. The connector has a distal first end adapted to receive a tube comprising a frusto-conical member, an adjacent elongated land, and a plurality of longitudinally spaced circumferential barbs, and a second end adapted to be coupled to the tubing. The elongated land creates a mechanical locking mechanism that enables the connector to operate at higher temperatures and pressures.  
      While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The invention can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an enlarged side view of the connector and an unattached tube.  
       FIG. 2  is an enlarged side view of the tube affixed to the connector, with the connector being encompassed by the tube.  
       FIG. 3  is an isometric view of the connector.  
       FIG. 4  is a section view taken along line A of  FIG. 1 . 
    
    
      The invention and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the invention defined in the claims. It is expressly understood that the invention as defined by the claims may be broader than the illustrated embodiments described below.  
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      A connector  10  of the type for connecting a landscaping apparatus with a pipefitting is generally shown at  10  in the FIGS.  
      Referring to  FIG. 1 , the connector  10 , the connector  10  has a distal first end that is adapted to receive tubing  80 , and a proximal second end that is adapted to be coupled to tubing  80 . The first end comprises a frusto-conical member  20  having a ramped surface beginning at a first end of the frusto-conical member  20  and ending at a second end that is essentially conical. This ramped surface increases in diameter and has an essentially consistent slope along a longitudinal length of the ramped surface, from the first end of the frusto-conical member  20  to the second end of the frusto-conical member  20 , creating a first sealing surface. The frusto-conical member&#39;s  20  surface is angled in such a manner as to provide easier insertion of the connector  10  into the tubing  80  and extends axially along the connector creating a distal barb  22 . The frusto-conical member&#39;s  20  distal barb  22  defines a first engaging surface between an inner surface  82  of the tubing  80  and an outside surface of the connector to provide a fluid seal.  
      The land  30  is longitudinally adjacent to the frusto-conical member with a diameter equal to or less then the minimum inner diameter of the tubing end  82  and elongated which allows the tubing to relax toward its unexpanded inner diameter after being expanded over the frusto-conical member to provide tighter coupling and sealing between the body and the tubing. The land  30  comprises a reduced diameter portion of the connector  10  and longitudinally extends from the distal barb  22  and ends at a predetermined distance from the distal barb  22 , where the land  30  has a diameter equal to or less then the minimum inner diameter of the tubing end  82 . The length of land  30  is predetermined by the degree of radial expansion of tubing  80  caused by barb  22  and the degree of resilience or strength of the elastic memory of the tubing  80  as it relaxes back to the smaller diameter of land  30 . With a constant diameter of barb  22  the greater the elastic memory or tendency of tubing  80  to relax quickly back to its original diameter, the shorter the length of land  30 . Similarly, with a constant degree of elastic memory of tubing  80 , the greater diameter of barb  22 , the greater the length that land  30  needs to be to obtain the desired seal.  
      The diameter of threads  40  is also a factor in determining the length of land  30 . The greater the radial extent of threads  40 , the greater the length of land  30  to allow sufficient length for the relaxation of tubing  80  against land  30  for the purpose of sealing against both land  30  and barb  22 .  
      Having the cylindrical land  30  be recessed  24  behind the distal barb  22  allows substantial relaxation in the tubing  80 , thereby providing a mechanical lock so that the tubing  80  can withstand higher temperatures and pressures. The land allows the tubing  80  to relax toward its unexpanded inner diameter  82  after being expanded over the distal barb to provide tighter coupling and sealing between the body and the tubing.  
      The first end further includes a second barbed surface longitudinally adjacent to the land that comprises a plurality of helical threads  40  longitudinally spaced apart and disposed between the land  30  and the second end of the body. The radial extent of threads  40  increases in the first proximal portion of the thread from the diameter of body  50  or land  30  to a predetermined constant radius. Similarly, the radial extent of threads  40  decreases from predetermined constant radius to the distal portion of the thread which descends to the diameter of body  50  or land  30 . Tubing  80  is thus screwed onto threads  40  against the radial elastic resisting force of tubing  80 .  
      Because of the spiral or helical form of threads  40 , threads  40  add little to the fluidic sealing of the connector  10 , but provide a convenient means whereby engagement and retention of tubing  80  onto the connector  10  is achieved under higher pressures. In the preferred embodiment of the invention the fluidic sealing surface or coupling with tubing  80  is moved forward to the distal end of connector  10  at barb  12  and away from the more proximal threads  40 . The mechanical coupling between tubing  80  and connector  10  is similarly moved proximally toward threads  40  away from distal barb  22 . Each of the helical threads  40  in the third section comprises a third engaging surface with the inner surface  82  of the tubing  80 . Each of the helical threads  40  also provide an individual conical land  42  disposed on the outer surface of the barbs. The conical lands  42  between each barb defines a space that aids in a engagement between the tubing  80  and the connector  10  and also increases the pull-off resistance of the connector  10  with each thread  40 .  
      It is also within the scope of the invention to render threads  40  as circular barbs with a ramped proximal and distal circular barb instead so that fluidic sealing by threads  40  is maximized at the expense of the ease of threaded engagement with tubing  80 . Having three separate conical and sealing surfaces provides a more redundancy in the fluidic seal.  
      As shown in  FIG. 2 , when the tubing  80  is fitted over the frusto-conical member  20  and into the elongated cylindrical land  30  the tubing  80  can relax behind the distal barb  22 , essentially providing a mechanical lock for the tubing  80  against the connector  10 . This allows the water pressure and temperature to be higher and the tubing  80   s  to be thinner and/or softer without causing failure.  
      When the connector  10  is inserted into the tubing  80 , the tubing  80  flexes and an inner surface  82  of the tubing  80  compresses radially inwardly onto the barbs so that the barbs can engage the inner surface  82  of the tubing  80  to prevent the connector  10  from being pulled off the tubing  80  under high pressures or higher temperatures. The threads  40  aid in the sealing of the tubing  80  once the connector has been pushed into the tubing, over the distal barb and beyond the cylindrical land  30  by turning the tubing  80  in a clockwise direction.  
      When the connector  10  and the tubing  80  are attached, as can be seen in  FIG. 2  the water travels from the connector  10  into the tubing  80  and then into the landscaping apparatus. Because the tubing  80  is engaged and sealed by the connector  10 , there are no leaks, and the connector  10  does not become pulled off of the tubing  80 .  
       FIG. 3  is an isometric view showing that the proximal second end of the connector  10 , which is only required when the connector is affixed to a female threaded fitting, can connect to a mating fitting (not shown) and includes a coupling  60  disposed at the end opposite to the end that is inserted into the tube. The coupling can include a flanged portion adapted to receive a tool, such as a wrench, to hold the coupling  60  as the connector  10  is being connected to the mating fitting (not shown). The threaded portion  70  can comprise a male or female threaded portion  70 . Additionally the second end can include any suitable coupling  60  mechanisms known to those skilled in the art.  
      A method of coupling irrigation tubing to a connector  10  includes disposing the tubing  80  over the distal barb  22  to expand the tubing in order to allow the tubing  80  to relax its unexpanded inner diameter  82  to provide tighter coupling and sealing between the connector  10  and the tubing  80  by use of an elongated land  30  longitudinally adjacent to the distal barb  22 . This expansion of the tubing  80  over the distal barb  22  and over the cylindrical land  30  causes the tubing  80  to engage with the threads  40 , and allows the tubing  80  to be turned in a clockwise direction for a tighter seal with the connector  10 .  
       FIG. 4  shows a sectional view of the connector taken along line A in  FIG. 1 , the connector having a generally cylinder diameter D throughout to further the efficient flow of water between the tubing  80  and the mating fitting (not shown).  
      Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations.  
      The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself.  
      The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination.  
      Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.  
      The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention.