Patent Publication Number: US-2009218806-A1

Title: Weldable pipe fitting

Description:
TECHNICAL FIELD 
     The present invention relates generally to the field of pipe fittings, and more particularly to an improved weldable male pipe outlet or connection. 
     BACKGROUND ART 
     It is known in the prior art that male and female fittings may be welded to provide a fluid handling piping system connection. The male and/or female connections are tack welded on to the piping system to hold them in place prior to a conventional weld being applied between the fitting and the parent pipe, pipe coupling or other piping connection. A conventional weld is formed by heating and applying a separate weld filler along the seam between the two adjacent surfaces of the male and female pieces. The weld filler typically comes in wire form. 
     DISCLOSURE OF THE INVENTION 
     With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiment, merely for the purposes of illustration and not by way of limitation, the present invention broadly provides an improved weldable male fitting ( 15 ) comprising a fitting body ( 16 ) of a first material elongated along a longitudinal axis and having an outer surface ( 23 ,  27 ) and an inner surface ( 20 ) defining a through-passage ( 28 ), the outer surface having a first portion ( 23 ) and a shoulder ( 18 ) extending radially from the first portion, the shoulder being integral to the fitting body and formed substantially of the first material, the first portion of the outer surface adapted to engage a corresponding aperture ( 39 ) in a mating member ( 35 ), and the integral shoulder adapted to be heated into provide an autogenous weld ( 45 ) between the fitting body and the mating member. 
     The first material may be stainless steel. The outer surface may be a generally cylindrical surface and the shoulder may be an annular ring extending from the cylindrical surface. The inner surface may be threaded. The fitting body may further comprise an annular end portion ( 21 ) and a tapered surface ( 22 ) extending between the annular end portion and the first portion the outer cylindrical surface. The annular shoulder may have an axial length ( 29 ) and a radial thickness ( 30 ) selected to provide a desired weld strength and filler material between the fitting body and the mating member. The shoulder may be dimensioned and positioned axially along the outer surface to provide a desired weld strength between the fitting body and the mating member. The mating member may be a pipe having a collared aperture and the fitting may provide a tap in the pipe. 
     The general object of the invention is to provide a fitting that may be more easily welded in place. 
     Another object is to provide a fitting which may be properly positioned in place for welding. 
     Another object is to provide a fitting that allows for the weld filler to be correctly located and provided in the correct amount for the desired strength of the weld. 
     Another object is to provide a fitting which can be welded with no undercut and which provides improved weld strength and quality. 
     Another object is to provide a fitting which may be welded without the need for externally added filler wire. 
     Another object is to provide a fitting which is easily aligned and inserted in place. 
     These and other objects and advantages will become apparent from the foregoing and ongoing written specification, the drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the preferred embodiment of the fitting. 
         FIG. 2  is a longitudinal vertical sectional view of the fitting shown in  FIG. 1 , taken generally on line  2 - 2  of  FIG. 1 . 
         FIG. 3  is a perspective view of the preferred embodiment of a mating member having a socket or aperture adapted for engagement with the fitting shown in  FIG. 1 . 
         FIG. 4  is a perspective view of the fitting shown in  FIG. 1  inserted into the corresponding aperture of the mating member shown in  FIG. 3 . 
         FIG. 5  is a perspective view of the fitting welded to the mating member shown in  FIG. 3 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions or surfaces consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate. 
     Referring now to the drawings, and more particularly to  FIG. 1  thereof, this invention provides an improved male fitting, of which the presently preferred embodiment is generally indicated at  15 . As shown in  FIGS. 1-2 , fitting  15  is generally a cylindrical ring-shaped annular structure elongated along axis x-x and bounded by a rightwardly-facing annular vertical surface  19 , an inwardly-facing horizontal cylindrical surface  20 , a leftwardly-facing annular vertical surface  21 , an outwardly and leftwardly-facing annular frusto-conical surface  22 , an outwardly-facing horizontal cylindrical surface  23 , a leftwardly-facing annular vertical surface  24 , an outwardly-facing horizontal cylindrical surface  25 , a rightwardly-facing annular vertical surface  26 , and an outwardly-facing horizontal cylindrical surface  27 , joined at its right marginal end to the outer marginal end of surface  19 . 
     Inner horizontal cylindrical surface  20  is a threaded surface and defines through-passage  28 . Surfaces  24 ,  25  and  26  define shoulder  18 , which extends radially from first portion  23  of the outer cylindrical surface of body  16  of fitting  15 . Body  16  and shoulder  18  are formed of substantially the same material and shoulder  18  is integral to body  16  of fitting  15 . In the preferred embodiment, fitting  15  is machined from stainless steel. 
     As shown in  FIGS. 3-5 , fitting  15  is adapted to be welded to a mating member  35 . Because fitting  15  includes integrated shoulder  18 , it is adapted to be heated and to provide the weld and weld filler material between fitting  15  and mating member  35  after the end of fitting  15  is inserted into a corresponding socket or aperture  39  in mating member  35 . Shoulder  18  has an axial length  29  and a radial height  30  from outer surface  23  that is selected to provide the desired weld strength and filler material. The axial location of shoulder  18  along outer surface  23 ,  27  and the radial height  30  and axial width  29  can be selected so as to provide the desired weld filler material in the correct location and in the correct amount for autogeneously welding fitting  15  to collar  38  in mating member  35 . 
       FIG. 3  shows an embodiment of a mating member with which fitting  15  may be used. In this embodiment, mating member  35  is the band  60  of the pipe repair clamp shown and described in U.S. Pat. No. 6,830,268 titled “Pipe Repair Clamp”, the entire disclosure which is incorporated herein by reference. However, in this embodiment, pipe repair clamp  35  is modified to include an aperture  39 . As shown in  FIG. 3 , aperture  39  is formed by drawing out a collar  38  in band  60 , the spinning of which increases the strength of stainless steel band  60 . By welding fitting  15  to collar  38 , heat is not applied directly to band  60 , as heat is applied to only the end of collar  38  during welding. 
     Collar  38  is defined by an outwardly-facing horizontal cylindrical surface  42 , a rightwardly-facing annular vertical surface  41  and an inwardly-facing horizontal cylindrical surface  40 . Inner cylindrical surface  40  defines aperture  39  in member  35 . As shown in  FIG. 4 , inner cylindrical surface  40  of member  35  and outer cylindrical surface  23  of fitting  15  are configured such that fitting  15  may be inserted into aperture  39  and held in place by the contact between adjacent concentric surfaces  40  and  23 . The left end  21  of fitting  15  is provided with a taper  22  so that the end portion of fitting  15  will fit tightly in aperture  39  up to the left side  24  of shoulder  18 . 
     Because of the close dimensioning of the outer cylindrical surface  23  and inner cylindrical surface  40  of fitting  15  and mating member  35 , respectively, fitting  15  may be inserted and will remain in place without any tack welding. Tack welding is not needed to locate fitting  15  in proper finished welding position because shoulder  18  is configured to facilitate the proper positioning of fitting  15  relative to member  35  and the small tolerance between opposed surfaces  23  and  40  allow fitting  15  to be held in place without the need for such a tack weld. Fitting  15  is positioned properly when the leftwardly-facing vertical annular surface  24  of shoulder  18  abuts the rightwardly-facing vertical annular surface  41  of collar  38  in member  35 . Because shoulder  18  is machined and is an integral part of fitting  15 , it allows for fitting  15  to be properly located axially with respect to aperture  39  of mating member  35 . Thus, even under conditions found at outdoor, underground or other non-optimal installation sites, fitting  15  can be easily positioned so as to provide the proper weld joint axis, proper weld material, the appropriate axial penetration depth of fitting  15  in aperture  39 , the appropriate axial extension length of fitting  15  from aperture  39  for the desired assembly dimensional requirements. The axial thickness  29  and radial height  30  of shoulder  18  may be varied to accommodate varying material thicknesses, fitting diameters and optimal welding processes and strengths, as needed. 
     Once fitting  15  is placed in proper alignment in aperture  39  with the left annular vertical surface  24  of shoulder  18  contacting the rightwardly-facing annular vertical surface  41  of collar  38 , heat is applied to shoulder  18  to autogeneously weld the two parts together.  FIG. 5  shows the autogenous weld  45  between fitting  15  and member  35 . In the prior art the weld would have been made with the application of separate weld filler wire between the adjacent surfaces of fitting  15  and member  35 . With fitting  15 , shoulder  18  is adapted to be heated and to provide the weld and weld filler material between the outer surface of fitting  15  and collar  38 . Thus, in this embodiment fitting  15  is used to tap a band, pipe or tank. 
     While the presently-preferred form of the fitting has been shown and described, and several embodiments discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims.