Abstract:
A transition adapter for connecting together ENT tubing and threaded conduit has an ENT connector socket on one end portion thereof and a threaded socket on an opposite end portion thereon.

Description:
REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of U.S. Ser. No. 10/903,196 filed Jul. 30, 2004. 
     
    
     BACKGROUND  
       [0002]     This application relates to the art of electrical fittings and, more particularly, to an electrical fitting in the form of a transition adapter for connecting together an ENT tube and an externally threaded end portion of a pipe. The application particularly concerns stub down adapters and will be described with specific reference thereto. However, it will be appreciated that certain features of the fitting may be used with other types of adapters.  
       SUMMARY  
       [0003]     A fitting for connecting ENT conduit with an externally threaded end portion of a pipe has an ENT socket on one end portion and a threaded socket on its opposite end portion.  
         [0004]     The fitting may be a straight through fitting for connecting ENT conduit and threaded pipe coaxially, or may be a 90° fitting for connecting ENT tubing and threaded pipe perpendicular to one another.  
         [0005]     A mounting flange extends outwardly from the fitting at the end portion thereof that has the threaded socket therein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0006]      FIG. 1  is a perspective illustration of a fitting in accordance with the present application;  
         [0007]      FIG. 2  is another perspective illustration of the fitting;  
         [0008]      FIG. 3  is still another perspective illustration of the fitting;  
         [0009]      FIG. 4  is a top plan view thereof;  
         [0010]      FIG. 5  is a bottom view thereof;  
         [0011]      FIG. 6  is a side elevational view thereof;  
         [0012]      FIG. 7 . is another side elevational view thereof;  
         [0013]      FIG. 8  is a cross-sectional elevational view taken generally on line  8 - 8  of  FIG. 7 ;  
         [0014]      FIG. 9  is a perspective illustration of another embodiment;  
         [0015]      FIG. 10  is another perspective illustration thereof;  
         [0016]      FIG. 11  is a side elevational view thereof;  
         [0017]      FIG. 12  is a top plan view thereof;  
         [0018]      FIG. 13  is a bottom view thereof;  
         [0019]      FIG. 14  is an end elevational view thereof;  
         [0020]      FIG. 15  is an end view of the end opposite from  FIG. 14 ;  
         [0021]      FIG. 16  is a partial cross-sectional elevational view;  
         [0022]      FIG. 17  is a cross-sectional elevational view taken generally on line  17 - 17  of  FIG. 14 ; and  
         [0023]      FIG. 18  is a cross-sectional elevational view showing an externally threaded end portion of a pipe and an ENT tube received in the sockets in the fitting of  FIGS. 1-8 . 
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0024]     In this application, ENT is an acronym for electrical nonmetallic tubing of the type formed by a flexible corrugated tube that is made of plastic material such as PVC.  
         [0025]     Referring now to the drawings, wherein the showings are for purposes of illustrating representative embodiments only and not for purposes of limiting same,  FIGS. 1-8  show a tubular fitting A that is molded in one-piece of plastic material.  
         [0026]     Fitting A has a generally cylindrical body portion  10  with ENT and threaded connectors at opposite end portions thereof in the form of an ENT socket  10   a  and a threaded socket  10   b . A flat circular mounting flange  12  extends outwardly from the end of body portion  10  in which threaded socket  10   b  is formed. Mounting flange  12  has a flat bottom surface  16  that is positionable against a flat support surface, and has three equidistantly-spaced fastener receiving holes  18  for receiving fasteners to attach fitting A to the support surface.  
         [0027]     Generally cylindrical body portion  10  has a pair of openings  20 ,  22  formed therein generally midway of the length of ENT socket  10   a . Generally cylindrical body portion  10  has arcuate latch finger supports  26 ,  28  that are located opposite one another and bulge outwardly adjacent the ENT socket end of cylindrical body portion  10 .  
         [0028]     Opposite latch fingers  30 ,  32  project from latch finger supports  26 ,  28  into openings  20 ,  22  so that the openings are generally U-shaped around the latch fingers. Latch fingers  30 ,  32  have latch finger terminal end portions  36 ,  38  that project inwardly of the inner cylindrical surface of ENT socket  10   a . Latch finger end portions  36 ,  38  are receivable in an external circumferential groove in an ENT tube that is receivable within ENT socket  10   a.    
         [0029]     Latch finger supports  26 ,  28  space the pivot point of latch fingers  30 ,  32  outwardly from the outer surface of an ENT tube that is received within socket  10   a  to provide enhanced flexibility of the latch fingers, and to provide camming action that tends to bend the latch fingers inwardly toward the longitudinal axis of the ENT socket when a force is applied in a direction that tends to remove the ENT tube from the socket.  
         [0030]     An inwardly extending circumferential divider  40  is provided within generally cylindrical body portion  10  approximately midway between the opposite ends of the fitting. The end of an ENT tube that is received in ENT socket  10   a  normally engages divider  40 .  
         [0031]     Latch fingers  30 ,  32  have inner sloping surfaces  30   a ,  30   b ,  32   a ,  32   b  that are engaged by an ENT tube as it is inserted into ENT socket  10   a  for camming latch fingers  30 ,  32  outwardly so that the corrugated ENT tube can ratchet past latch finger end portions  36 ,  38 . When the end of the corrugated ENT tube bottoms out against divider  40 , latch finger end portions  36 ,  38  are received in an external circumferential groove in the ENT tube. Generally radial end surfaces  36   a ,  38   a  on latch finger end portions  36 ,  38  then are engageable with a generally radial groove sidewall on the ENT tube when a force is applied in a direction to remove the ENT tube from socket  10   a . This causes the fingers to bend generally radially inwardly and more securely hold the ENT tube against removal from the socket.  
         [0032]      FIGS. 9-17  show another embodiment in the form of a tubular 90° fitting B having a curved tubular portion  60  with ENT and threaded connectors  62 ,  64  at opposite end portions thereof. ENT connector  62  has a generally cylindrical socket  62   a  for receiving an end portion of a corrugated ENT tube. Threaded connector  64  has a threaded socket  64   a  therein for receiving an externally threaded end portion of an electrical conduit. Sockets  62   a  and  64   a  extend generally perpendicular to one another at opposite ends of tubular portion  60 .  
         [0033]     A flat circular mounting flange  66  extends outwardly from fitting B at the threaded connector end thereof. Three equidistantly-spaced fastener receiving holes  68  are provided in mounting flange  66  for receiving fasteners to attach flange  66  to a flat support surface.  
         [0034]     A reinforcing web  70  extends between mounting flange  66  and tubular portion  60  to reinforce tubular portion  60  against bending or breakage. Web  70  extends the full length of curved tubular portion  60  and along threaded connector end portion  64 , but does not extend along ENT connector end portion  62 . ENT connector end portion  62  is spaced outwardly from the outer periphery of mounting flange  66 , and web  70  has an inclined leading edge  70   a  that is inclined upwardly and outwardly from the outer periphery of mounting flange  66  toward ENT connector  62 .  
         [0035]     Arcuate latch finger supports  72 ,  74  bulge outwardly from cylindrical ENT connector portion  62  and have latch fingers  76 ,  78  extending therefrom into opposite openings  80 ,  82  in the wall of connector portion  62 . Latch fingers  76 ,  78  have latch finger end portions  86 ,  88  that are receivable in an external circumferential groove in an end portion of an ENT tube. Latch fingers  76 ,  78  are located on opposite sides of a plane  90  that bisects fitting B. Latch fingers  76 ,  78  on fitting B have cam surfaces and radial surfaces as described with reference to items  30   a ,  30   b ,  32   a ,  32   b ,  36   a ,  38   a  on latch fingers  30 ,  32  of fitting A.  
         [0036]      FIG. 18  shows an end portion of a corrugated ENT tube  110  received in socket  10   a  and a pipe  112  of metal or plastic having an externally threaded end portion received in socket  10   b . ENT tubes and externally threaded end portions of pipes are receivable in the same manner in sockets  62   a  and  64   a  of fitting B.  
         [0037]     ENT sockets  10   a ,  62   a  are sized for receiving either one-half inch, three-quarter inch or one inch trade size ENT tubing. One-half inch trade size ENT tubing has an outside diameter of 0.832-0.848 inches. Three-quarter inch trade size ENT tubing has an outside diameter of 1.040-1.060 inches. One inch trade size ENT tubing has an outside diameter of 1.305-1.325 inches.  
         [0038]     Threaded sockets  10   b ,  64   a  are sized for receiving either one-half inch, three-quarter inch or one inch threaded pipe. The threaded sockets may have any common type of pipe thread including, but not necessarily limited to, NPT—National Pipe Thread or National Pipe Tapered or American Standard Taper Pipe Thread; UNC—Unified National Coarse; UNF—Unified National Fine; UNEF—Unified National Extra Fine; NPS—National Pipe Straight; NPTF—Dryseal American Standard Taper Pipe Thread; NPSF—Drysteal American Fuel Internal Straight Pipe Thread; NPSI—Dryseal American Intermediate Internal Straight Pipe Thread; and NPSM—American Standard Straight Mechanical Pipe Thread. Obviously, various metric pipe threads also may be used.  
         [0039]     Although the fittings can be configured to transition between different sizes of ENT and externally threaded conduits, the fittings normally connect ENT and threaded conduits of the same size. Thus, a fitting having an ENT socket for receiving a one-half inch trade size ENT tube will have a threaded socket for receiving an externally threaded end portion on a one-half inch trade size pipe and so on.  
         [0040]     Although the improvements of this application have been shown and described with reference to representative embodiments, it is obvious that alterations and modifications will occur to others skilled in the art upon the reading and understanding of this disclosure. Therefore, it is to be understood that the improvements may be practiced otherwise than as specifically described herein while remaining within the scope of the claims.