Abstract:
A liquid tight connector for connecting metallic or non-metallic conduit to a panels or junction box. The connector includes a forward end that accommodates either a spring steel adapter or a lock nut to secure the forward end to a panel in a liquid tight fit. A cover on the rearward end encloses an annular sealing ring and an annular retaining ring to form a conduit accepting channel including a conduit sealing portion and a conduit retaining portion. A conduit is secured to the rearward end of the connector by simply pushing it within the channel and tightening the cover to achieve a liquid tight fit. By eliminating disassembly and reassembly of parts, the connector provides significant labor savings over prior art liquid tight conduit connectors.

Description:
This application is a Continuation-In-Part of U.S. patent application Ser. No. 10/017,537 entitled “Liquid Tight Connector”, filed Oct. 22, 2001, now U.S. Pat. No. 6,616,194. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to connectors for conduit and specifically to an improved liquid tight connector for joining non-metallic or metallic conduit to junction boxes or panels. Conduit may be secured to the rearward end of the connector without the required tightening of nuts with hand tools as in prior art connectors. The forward end of the connector may be secured by a snap fitting, or, by a lock nut to create a liquid tight fit between the connector and the panel. 
     BACKGROUND OF THE INVENTION 
     Many prior art liquid tight connectors are commonly in use for connecting non-metallic or metallic conduit to panels or electrical boxes. These connectors are usually multi-piece devices that must be dismantled to fit the conduit into the fitting and then reassembled to secure the conduit. Most of these prior art fittings require the use of a hand tool to tighten a nut sufficiently to achieve a liquid tight connection between the conduit and the connector. Most prior art liquid tight connectors also require the tightening of a nut on the forward end of the fitting to achieve a liquid tight connection between the fitting and the panel or junction box. 
     For example, U.S. Pat. No. 4,900,068 to Law, granted Feb. 13, 1990 (hereinafter the &#39;068 patent) claims a liquid tight connector that accepts a non-metallic conduit that is grasped by fingers on a clip grasping on an annular ring on a ferrule. To fit the conduit into the liquid tight connector of the &#39;068 patent, an installer usually must remove a compression on the rearward end of the connector, insert the conduit into the fitting, and then tighten the compression nut with a hand tool such as a wrench to achieve a liquid tight fit. The forward end of the fitting is threaded and must be inserted into the knock-out of a panel or box, a nut is screwed onto the threaded end, and then a hand tool is typically used to secure the fitting to the panel or box. A hand tool therefore is typically employed to achieve a secure liquid tight fit on both the rearward end of the fitting, between the conduit and the fitting, and on the forward end of the fitting, between the fitting and the panel or box. 
     U.S. Pat. No. 5,072,072 granted to Bawa, et al., on Dec. 10, 1991 (hereinafter the &#39;072 patent) attempts to improve upon the fitting provided in the &#39;068 patent by providing a fitting that requires minimal torque on a gland nut to secure the conduit to the rearward end of the fitting. Upon tightening of the gland nut on the connector body claimed by the &#39;072 patent, the gland nut engages resilient fingers with minimal friction loss, thereby enhancing hand tightening or minimizing the torque required with a tightening tool. The &#39;072 patent therefore requires the separate operation of tightening a nut either by hand or with a tightening tool. The forward end of the fitting in the &#39;072 patent is typically threaded and requires the use of a nut to secure the fitting to the panel and also an O-ring between a forward shoulder and the panel to achieve a liquid tight fit. 
     U.S. patent application Ser. No. 10/017,537 entitled “Liquid Tight Connector”, filed Oct. 22, 2001 by Gretz, now U.S. Pat. No. 6,616,194 and incorporated herein by reference in its entirety, provided a liquid tight connector that solved many of the problems inherent in prior art connectors. The connector of U.S. Pat. No. 6,616,194 provided a one-piece connector assembly, which could be installed to a panel by simply pushing a conduit into a channel on its rearward end and then pushing the forward end into a knockout in a panel or junction box. By providing a connector in which disassembly of parts and tightening of nuts was not required, the connector of the aforementioned application therefore provided a significant labor saving device over prior art liquid tight connectors for conduit. This improved connector included a utinary retainer body to function in cooperation with an integral ferrule on a tubular body member to create a conduit accepting channel on the rearward end of the connector for creating a liquid tight fit between a conduit and the connector. 
     The present invention improves upon the connector of U.S. Pat. No. 6,616,194 by replacing the unitary retainer body with an annular sealing ring and an annular retainer ring to improve the sealing effectiveness and the liquid tightness between the conduit and the connector. 
     SUMMARY OF THE INVENTION 
     The invention is an assembly of parts that is provided as a one-piece connector for achieving a liquid tight seal between a non-metallic or metallic conduit and an electrical panel or box. The connector includes a tubular member with an axial bore there through and a centrally located flange dividing it into two ends including a forward end having threads on its exterior surface and a rearward end having an extending ferrule. A spring steel adapter or a lock nut may be used to connect the forward end to a panel in a liquid tight fit. The rearward end accommodates an annular sealing ring and an annular retaining ring held within an annular cover member. A conduit accepting channel is thereby formed within the rearward end. A conduit may be secured to the rearward end of the connector by simply pushing it within the channel and tightening the cover to achieve a liquid tight fit. The connector provides significant labor savings over prior art liquid tight conduit connectors as disassembly of parts prior to insertion of the conduit is eliminated. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the tubular body portion of the liquid tight connector of the present invention. 
     FIG. 2 is an end view of the ferrule bushing as viewed from the right side of FIG. 1 
     FIG. 3 is an end view of the ferrule bushing as viewed from the left side of FIG.  1 . 
     FIG. 4 is a plan view of the retainer body cover portion of the liquid tight connector. 
     FIG. 5 is a plan view of an annular retainer ring that forms part of the liquid tight connector of the present invention. 
     FIG. 6 is an end view of the retainer ring as viewed from the left side of FIG.  5 . 
     FIG. 7 is a plan view of an annular sealing ring that forms part of the liquid tight connector of the present invention. 
     FIG. 8 is a sectional view of the sealing ring taken along line  8 — 8  of FIG.  7 . 
     FIG. 9 is a plan view of a preferred embodiment of the liquid tight connector of the present invention. 
     FIG. 10 is a sectional view of the liquid tight connector taken along line  10 — 10  of FIG.  9 . 
     FIG. 11 is a perspective view showing a section of conduit, the preferred embodiment of the liquid tight connector, and a junction box to which the connector will be fitted. 
     FIG. 12 is an exploded view of the preferred embodiment depicting, from left to right, a snap ring, sealing washer, tubular body, sealing ring, retaining ring and cover member. 
     FIG. 13 is an exploded view of a second embodiment of the liquid tight connector depicting, from left to right, a lock nut, sealing washer, tubular body, sealing ring, retaining ring and cover member. 
    
    
     TABLE OF NOMENCLATURE 
     
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Part No. 
                 Part Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 20 
                 liquid tight connector 
               
               
                 22 
                 snap ring 
               
               
                 24 
                 sealing washer 
               
               
                 28 
                 tubular body 
               
               
                 30 
                 sealing ring 
               
               
                 32 
                 retaining ring 
               
               
                 34 
                 cover member 
               
               
                 36 
                 flange 
               
               
                 38 
                 forward end of tubular body 
               
               
                 40 
                 rearward end of tubluar body 
               
               
                 42 
                 forward face of flange 
               
               
                 44 
                 rearward face of flange 
               
               
                 46 
                 ferrule 
               
               
                 48 
                 shoulder 
               
               
                 50 
                 outer periphery of shoulder 
               
               
                 52 
                 threads on shoulder 
               
               
                 54 
                 nose portion of tubular body 
               
               
                 56 
                 threads on nose portion 
               
               
                 58 
                 hex surface 
               
               
                 60 
                 forward end of cover 
               
               
                 62 
                 rearward end of cover 
               
               
                 64 
                 forward end of retaining ring 
               
               
                 66 
                 rearward end of retaining ring 
               
               
                 68 
                 U-shaped cuts 
               
               
                 70 
                 outer periphery of retaining ring 
               
               
                 72 
                 conduit retaining tangs 
               
               
                 74 
                 central bore through retaining ring 
               
               
                 76 
                 wall of retaining ring 
               
               
                 78 
                 integral outer tabs 
               
               
                 80 
                 free ends 
               
               
                 82 
                 inner periphery of sealing ring 
               
               
                 84 
                 first outer edge of sealing ring 
               
               
                 86 
                 second outer edge of sealing ring 
               
               
                 88 
                 center of inner periphery of sealing ring 
               
               
                 90 
                 outward tangs on snap ring 
               
               
                 92 
                 inwardly turned edge of snap ring 
               
               
                 94 
                 threads on cover member 
               
               
                 96 
                 lip on cover 
               
               
                 98 
                 face of the shoulder 
               
               
                 100 
                 conduit accepting channel 
               
               
                 102 
                 forward portion of accepting channel 
               
               
                 104 
                 rearward portion of accepting channel 
               
               
                 106 
                 rearward end of connector 
               
               
                 108 
                 conduit 
               
               
                 110 
                 junction box 
               
               
                 112 
                 aperture 
               
               
                 114 
                 forward fastening arrangement 
               
               
                 116 
                 forward end of connector 
               
               
                 118 
                 lock nut 
               
               
                 120 
                 wall of junction box 
               
               
                   
               
             
          
         
       
     
     DESCRIPTION OF THE INVENTION 
     According to the present invention, the present invention is a liquid tight connector for securing a conduit to a panel. Referring to the exploded view of the liquid tight connector  20  in FIG. 12, the preferred embodiment includes, from left to right, a snap ring  22 , sealing washer  24 , tubular body  28 , sealing ring  30 , retaining ring  32 , and cover member  34 . 
     With reference to FIG. 1, a flange  36  divides the tubular body  28  into a forward end  38  and a rearward end  40 . The ends of the tubular body  28  are referred to herein according to the direction they will face when used in conjunction with a box or panel (not shown), with the forward end  38  facing the panel and the rearward end  40  facing away from the panel. The flange  36  includes a forward face  42  and a rearward  44  face. The rearward end  40  includes an integral ferrule  46  that extends from the rearward face  44  of the flange  36 . Also extending from the rearward face  44  is an integral shoulder  48  outwards of and concentric to the ferrule  46 . The outer periphery  50  of the shoulder  48  includes threads  52 . The forward end  38  of the tubular body  28  includes an integral tubular nose portion  54  extending from the forward face  42  of the flange  36  and including threads  56  on its outer periphery. In the preferred embodiment, the exterior periphery of the flange includes a hex surface  58 . 
     Referring now to FIG. 2, an end view of the tubular body  28  is depicted as viewed from the right side of FIG.  1 . The ferrule  46  is shown extending from the rearward face  44  of the flange  36 . Outwards of and concentric to the ferrule  46  is the shoulder  48  extending from the rearward face  44  of the flange. 
     As depicted in FIG. 3, an end view of the tubular body  28  as viewed from the left side of FIG. 1, the nose portion  54  of the tubular body  28  extends from the forward face  42  of the flange  36  and includes threads  56  on its outer periphery. 
     Referring to FIG. 4, the cover member  34  includes a forward end  60  that will face the tubular body when the liquid tight connector is assembled and a rearward end  62  that will face away from the tubular body. 
     Referring to FIGS. 5 and 6, the tubular retaining ring  32  includes a forward end  64  that will face the tubular body (not shown) and a rearward end  66 . U-shaped cuts  68  on the outer periphery  70  of the retaining ring  32  define conduit retaining tangs  72  that extend into the axial bore  74  through the retaining ring  32 . The conduit retaining tangs  72  extend into the central bore  74  of the retaining ring  32  from the U-shaped cuts  68  in the wall  76  of the retaining ring  32 . The conduit retaining tangs  72  include integral outward tabs  78  extending outwards of the outer periphery  70  of the retaining ring  32  and free ends  80  extending into the central bore  74 . 
     With reference now to FIGS. 7 and 8, the sealing ring  30  of the preferred embodiment includes an inner periphery  82  having outer edges  84  and  86  and a center  88 . The preferred embodiment of the sealing ring is constructed of an elastomeric material and is tapered as shown in FIG. 8 from a wider diameter at the outer edges  84 ,  86  to a narrower diameter at the center  88 . 
     With reference now to FIGS. 9 and 10, the preferred embodiment of the liquid tight connector  20  includes a snap ring  22  fitted on the nose portion  54  on the forward end  38  of the tubular body  28 . Outward tangs  90  on the snap ring  22  restrain the sealing washer  24  on the nose portion  54 . The snap ring  22  may be held on the nose portion  54  by an inwardly turned forward edge  92  as shown in FIG.  10 . Further details of the snap ring  22  may be found in U.S. Pat. No. 6,080,933, issued Jun. 27, 2000 in the name of Thomas J. Gretz for “Snap in Cable Connector”, and herein incorporated by reference in its entirety. The ferrule  46  is shown extending out of the rearward end  62  of the cover member  34 . 
     Referring to FIG. 10, the preferred embodiment of the liquid tight connector is assembled by sliding first the sealing ring  30  and then the retaining ring  32  over the ferrule  46 , and then screwing the cover member  34  onto the tubular body  28 . The forward end  60  of the cover  34  contains threads  94  that engage the threads  52  on the shoulder  48  of the tubular body  28 . The sealing ring  30  and retaining ring  32  are thus held within the cover member  34  as shown. An inward-turned lip  96  on the rearward end  62  of the cover urges the retaining ring  32  against the sealing ring  30  until the forward end of the sealing ring is flush against the face  98  of the shoulder  48 . Once the cover  34  is tightened on the shoulder  48 , the retaining ring  32  and sealing ring  30  are held concentrically around the ferrule  46  thereby creating a conduit accepting channel  100  there between. The conduit accepting channel  100  includes a forward portion  102  between the ferrule  46  and the sealing ring  30  and a rearward portion  104  between the ferrule  46  and the retaining ring  32 . The conduit retaining tangs  72  include free ends  80  that extend inwardly and forwardly from the retaining ring  32  into the forward portion  102  of the channel  100 . The channel  100  is open at the rearward end  106  of the connector  20  and is typically sized to accept a standard grade of conduit (not shown). 
     Referring to FIG. 11, the open end of the conduit accepting channel  100  is visible in this perspective view showing a section of conduit  108 , the preferred embodiment of the liquid tight connector  20 , and a junction box  110  containing several apertures  112  therein. 
     With reference to FIGS. 11-13, the liquid tight connector  20  includes a forward fastening arrangement  114  for securing the forward end  116  of the connector  20  to a junction box  110 . The forward fastening arrangement  114  could be a snap ring  22  and sealing washer  24  as shown in the preferred embodiment of FIG. 12, or a lock nut  118  and sealing washer  24  as shown in the second embodiment in FIG.  13 . When the forward fastening arrangement  114  is a snap ring  22  and sealing washer  24 , the forward end  116  is simply pushed into an appropriate aperture  112  until the outward tangs  90  pass the wall of the junction box and snap outwards thereby locking the nose portion  54  of the connector  20  into the aperture  112 . When the forward fastening arrangement  114  is a lock nut  118  and sealing washer  24 , the nose portion  54  of the connector  20  is simply inserted in an aperture  112  and the lock nut  118  screwed onto the threaded nose portion  54  until tight against the inside wall of the junction box  110 , thereby locking the nose portion  54  of the connector  20  into the aperture  112 . 
     Operation of the liquid tight connector may best be explained by reference to the preferred embodiment shown in FIGS. 10 and 11. The liquid tight connector  20  is connected to a panel or junction box  110  by simply grasping the conduit  108 , inserting it into the conduit accepting channel  100  on the rearward end  106  of the connector  20 , and pushing the conduit  108  into the channel  100  until the end of the conduit is pushed fully into the channel  100 . After the conduit  108  is secured to the connector  20 , the forward end  116  of the connector  20  is pushed into the knockout aperture  112  of a junction box  110  until the outward tangs  90  clear the wall  120  of the junction box  110 . The snap ring  22  is constructed of a resilient material such as spring steel and the outward tangs  90  are oriented, in their unbiased position, outward and rearwards on the snap ring  22 . As the outward tangs  90  enter the knockout aperture  112  they are compressed inwardly. Further advancement of the snap ring  22  into the knockout aperture  112  eventually causes the outward tangs  90  to clear the wall  120  of the junction box  110  at which point the outward tangs  90  snap back to their unbiased position thereby locking the connector  20  securely to the junction box  110 . 
     Alternatively, to allow easier insertion of the conduit  108 , the cover  34  may be screwed partially onto the shoulder  48  and the conduit inserted therein. The inner diameter of the cover member is typically slightly tapered from a wider diameter at the forward end  60  of the cover to a narrower diameter at the rearward end  62  of the cover  34 . The interior walls of the cover  34  preferably are tapered downward at an angle of 2 degrees from the forward end  60  to the rearward end  62 , therefore sloping the inner bore of the cover at an angle of 2 degrees from front to rear. With the cover  34  screwed partially onto the shoulder  48 , the retaining ring  32  is not forced fully against the lip  96 , as the effective outer diameter of the retaining ring  32  at the integral outward tabs  78  is larger than the inner diameter of the cover  34  at the rearward end  62 . Therefore the free ends  80  of the conduit retaining tangs  72  are not extended fully into the channel  100 . A conduit  108  can then be inserted into the channel  100  and encounter minimal resistance. After insertion of the conduit  108 , the cover member  34  is screwed fully onto the shoulder  48  thereby forcing the retaining ring  32  further against the sealing ring  30  and towards the face  98  of the shoulder  48 . This in turn causes the narrower diameter at the rearward end  62  of the cover to depress the tabs  78  and force the conduit retaining tangs  72  further into the channel, as depicted in FIG. 10 with the cover  34  fully screwed onto the shoulder  48 . 
     Referring to FIG. 10, for a liquid tight connector  20  having the interior walls of the cover  34  tapered downward at the preferred angle of 2 degrees from the forward end  60  to the rearward end  62 , the interior diameter of the cover  34  at the forward end  60  is typically 1.180 inches and the interior diameter of the cover  34  at the rearward end  62  is typically 1.130 inches. The exterior walls of the retaining ring  32  are also preferably tapered downward at an angle of 2 degrees from its forward end  64  to its rearward end  66 . The exterior diameter of the retaining ring  32  at the forward end  64  is typically 1.150 inches and the interior diameter of the retaining ring  32  at the rearward end  66  is typically 1.125 inches. The exterior diameter of the retaining ring  32  across the integral outward tabs  78  is preferably 1.160 inches. As a result of the interior 2 degree taper on the cover member  34  and the exterior 2 degree taper on the retaining ring  32 , tightening of the cover  34  on the connector  20  will gradually depress the tabs  78  as the cover is tightened on the shoulder  48 . Full tightening of the cover  34  upon the connector  20  will force each of the tabs  78  to be depressed approximately 0.010 to 0.015 inches, thereby causing the tabs  78  to tightly grip the conduit surface (not shown). 
     Conduit is offered in various trades sizes, such as ¼″, ½″, ¾″, etc. Underwriters&#39; Labs has created standards for these trade sizes including specifications for the outer and inner diameters of the various trade sizes. Therefore, the preferred embodiment of the liquid tight connector  20  of the present disclosure can be constructed for any trade size of conduit by sizing the conduit accepting channel  100 , as shown in FIG. 8, to handle the desired trade size conduit. The liquid tight connector can therefore be constructed for ¼″, ½″, ¾″, or any other trade size conduit. The nose portion  54 , snap ring  22 , and sealing washer  24  can likewise be constructed of an appropriate size to enable rapid snap-in connection of the forward end  116  of the connector  20  to any trade size of knockout aperture  112 . 
     Referring again to FIG. 12, the pieces of the connector assembly  20  are, from left to right, the snap ring  22 , the sealing washer  24 , the tubular body  28 , the sealing ring  30 , the retaining ring  32 , and the cover member  34 . The snap ring  22  is preferably constructed of spring steel. The sealing washer  24  is preferably constructed of Santoprene™, which is a trademark of Advanced Elastomer Systems, L.P., but may be constructed of any similar elastomer. Additionally, it may be preferable to construct the sealing washer  24  of a flame retardant grade of thermoplastic elastomer to meet Underwriters Laboratories flame retardant requirements, such as grades UL 94 V-0 or UL 94 HB. The ferrule bushing is preferably constructed of a zinc alloy, such as Zarnak™ 7. Constructing the tubular body  28  of zinc alloy and the snap ring  22  of spring steel enables the connector  20  to establish electrical continuity between the metallic conduit and a metal panel. The retaining ring  32  and the cover member  34  are preferably molded of plastic. The preferred material of construction for the retaining ring  32  is polycarbonate and the preferred material of construction for the cover member  34  is nylon. 
     Although the description above contains many specific descriptions and proposed sizes, these should not be construed as limiting the scope of the invention but as merely providing illustrations of a preferred embodiment of the liquid tight connector of this disclosure. Typical sizes are provided to illustrate a given embodiment of the present invention and should not be construed as limiting its scope. 
     Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the specific examples given.