Patent Publication Number: US-2006012166-A1

Title: Articulating pipe joint

Description:
RELATED APPLICATIONS  
      This application claims the benefit of Provisional U.S. Patent Application 60/587,388, filed Jul. 13, 2004, which is incorporated by reference. 
    
    
     TECHNICAL FIELD  
      This technology relates to joints for connecting pipes in angular orientations.  
     BACKGROUND  
      An installation of pipes, and especially those that are installed underground, may include pipes that need to be connected at an angle for which an elbow or other fixed pipe joint is unavailable. An articulating pipe joint is thus configured with tubular sections that are rotatable through a range of angular orientations relative to each other. This provides a corresponding range of angles at which pipes can be connected by the joint.  
     SUMMARY  
      An apparatus comprises a tubular pipe joint section having a) a first circular rim portion, b) a non-coaxial second circular rim portion configured to receive the first circular rim portion of a duplicate pipe joint section coaxially in rotational sliding engagement, and c) an elliptical body wall extending from the first circular rim portion to the second circular rim portion. 
    
    
     DRAWINGS  
       FIG. 1  is a sectional view of an articulating pipe joint.  
       FIG. 2  is a perspective view of the pipe joint of  FIG. 1 .  
       FIG. 3  is a sectional view of another articulating pipe joint.  
       FIG. 4  is a side view of another articulating pipe joint.  
    
    
     DESCRIPTION  
      The pipe joints illustrated in the drawings have parts that are examples of the structural elements recited in the claims. The illustrated pipe joints thus include examples of how a person of ordinary skill in the art can make and use the claimed invention. They are described here to meet the enablement and best mode requirements of the patent statute without imposing limitations that are not recited in the claims.  
      As shown in  FIGS. 1 and 2 , a plastic pipe joint  10  has two sections  12  and  14  connected in series. These examples of the two parts  12  and  14  of the joint  10  have the same size and shape, and are preferably formed of the same plastic material. Each has a first open end portion  20 , a second open end portion  22 , and a tubular body wall  24  extending longitudinally between the opposite end portions  20  and  22 . The opposite end portions  20  and  22  are circular, and are offset so as not to be coaxial with each other. Here, for example, the second end portion  22  of each part  12  and  14  is inclined from the first end portion  20  at an angle A. The body walls  24 , which thus extend longitudinally between non-coaxial circular end portions  20  and  22 , are elliptical with longitudinal centerlines  25 .  
      More specifically, the first end portion  20  is configured as a circular rim with a central axis  29 . A planar edge surface  32  of the first end portion  20  lies in a plane perpendicular to the axis  29 . An annular inner surface  34  of the first end portion  20  has a uniform diameter centered on the axis  29 . An outer bearing surface  36  has a convex contour that is bowed radially outward, as shown in the cross-sectional view of  FIG. 1 , with a correspondingly non-uniform diameter that also is centered on the axis  29 .  
      As best shown in  FIG. 1  at the right-hand end of the second part  14 , the second end portion  22  of each part  12  and  14  also is configured as a circular rim. It has a frusto-conical edge surface  40  that is centered on a corresponding axis  41 . The axis  41  of one end of each part  12  or  14  is offset from the axis  29  at the other end. In this particular example, the axes  29  and  41  at the opposite ends of each part  12  and  14  are skewed relative to each other at the angle A. The angle A is preferably less than about 45° and, in the illustrated example, is about 30°. As further shown in  FIG. 1 , the axes  29  and  41  at the opposite ends of the parts  12  and  14  in the illustrated example are equally skewed relative to the longitudinal centerline  25  of the respective body wall  24 .  
      The second end portion  22  of each part  12  and  14  further has three inner surfaces  42 ,  44  and  46 . Each of the three inner surfaces  42 ,  44  and  46  is an annular, circular surface centered on the axis  41  at that end of the part  12  or  14 . The second and third of those surfaces  44  and  46  have conical contours. The first  42  is a bearing surface with a concave contour that is bowed radially outward. That bearing surface  42  has a size and contour equal or nearly equal to the size and contour of the bearing surface  36  at the opposite end portion  20 . The complementary contours of the bearing surfaces  36  and  42  enable the first end portion  20  of either part  12  and  14  to be received coaxially within the second end portion  22  of the other part  12  or  14  in rotational sliding contact at the bearing surfaces  36  and  42 , as shown where these two parts  12  and  14  are joined at the center of  FIG. 1 .  
      The plastic material of which the second end portion  22  is formed, as well as the conical contours of the second and third inner surfaces  44  and  46 , enable the first end portion  20  to snap into releasably interlocked engagement with the second end portion  22  upon being moved forcefully into the installed position shown at the center of  FIG. 1 . The fit between the two parts  12  and  14  is preferably tight enough to retain them securely together, but permits the two parts  12  and  14  to be rotated relative to each other about their central axes  29  and  41  which, as shown in  FIG. 1 , are coincident at the engaged end portions  20  and  22 . A notch  50  beside the first inner surface  42  can receive an O-ring or other gasket or seal  52 , as shown in  FIG. 2 .  
      In this arrangement, the joint  10  can interconnect a pair of pipe structures (not shown) for articulation relative to each other. A female end portion of a first pipe structure, which may comprise a pipe, a pipe fitting, or another joint part, can be received over the first end portion  20  of the first joint part  12 . This can be done in a manner similar to that in which the second end portion  22  of the first joint part  12  is received over the first end portion  20  of the second joint part  14 , or in any other suitable manner. A male end portion of a second pipe structure can likewise be received within the second end portion  22  of the second joint part  14 . Those two pipe structures can then be rotated relative to each other upon rotation of the first and second parts  12  and  14  relative to each other as described above.  
      In an alternative arrangement, a single part like either of these two parts  12  and  14  could be used to interconnect two pipe structures for rotation relative to each other. A greater number of parts also could be used in a single joint  100 , as shown in  FIG. 3 . Other alternative joint structures could include one or more joint parts with opposite ends that are inclined at angles different from the angles A shown in  FIG. 1 . Also, one or more joint parts in a connected series may have an angle of inclination or other axially offset configuration that differs from that of one or more of the other joint parts in the series.  
      Another alternative joint  110  is shown in  FIG. 4 . This joint  110  has sections  112  and  114  that are the same as the sections  12  and  14  of the joints  10  and  100 , except that the second end portions  122  of these joint sections  112  and  114  have notches  123 . The notches  123  define separately flexible tabs  124  that facilitate radial deflection of the second end portion  122  upon insertion of a first end portion  120  (or  20 ).  
      This written description sets forth the best mode of carrying out the invention, and describes the invention so as to enable a person of ordinary skill in the art to make and use the invention, by presenting examples of the elements recited in the claims. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples, which may be available either before or after the application filing date, are intended to be within the scope of the claims if they have elements that do not differ from the literal language of the claims, or if they have elements with insubstantial differences from the literal language of the claims.