Abstract:
A liquid tight connector for connecting non-metallic or metallic conduit to panels or similar devices. The connector is an effort and time saving device that allows connection of conduit to panels without the need to disassemble a portion of the connector and then reassemble again as in prior art devices. The connector allows an installer to simply push a conduit into one end of the connector and push the opposite end of the connector into an aperture in a panel. Liquid tight seals are created between the conduit and the connector and between the connector and the panel. By proper selection of the material of construction, the connector may be built for use with either metallic or non-metallic conduit.

Description:
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. A snap-fit feature is provided at the forward end to provide easy snap fitting into a panel. The connector therefore is a laborsaving device that greatly simplifies connection of conduit to panels and the like without the use of hand tools. 
     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 nut 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. 
     Therefore, as described above, the disadvantages of existing art liquid tight connectors for connecting conduit to panels include: 
     (a) The connector includes from two to five separate pieces, some of which must be disassembled at the jobsite prior to insertion of the conduit and then reassembled after the conduit is inserted into the rearward end. 
     (b) Prior art liquid tight connectors for conduit typically includes a compression, gland, or other nut that must be tightened by hand or by a tightening tool to achieve a liquid tight connection on the rearward end between the conduit and the connector. 
     (c) The forward end of prior art liquid tight connectors for conduit typically require the use of a nut that must be tightened with a hand tool to achieve a liquid tight fit between the connector and the panel. 
     (d) A separate washer or O-ring is typically provided with prior art liquid tight conduit connectors and must be assembled onto the forward end of the connector prior to insertion of the forward end into the knock-out on a panel or box. 
     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. The forward end accommodates a spring steel adapter and a washer. The rearward end accommodates a tubular retainer body and a tubular retainer body cover. The connector is an assembly of the separate pieces, none of which need to be disassembled when placed in use. The retainer body is held around the ferrule or rearward end by the retainer body cover that is screwed onto a threaded shoulder extending from the central flange. The washer is held on the forward end of the connector by outward projecting tangs in the spring steel adapter, which in turn is either snap-fitted or screwed onto the forward end. The connector assembly has the advantages of providing a one-piece connector assembly which may be simply installed by pushing a conduit into a channel on the rearward end of the connector and then pushing the forward end of the connector into a knock-out in a panel or junction box until the outward projecting tangs on the steel adapter snap into place to engage the wall of the panel or box. The connector therefore is a significant labor saving device over prior art liquid tight conduit connectors as disassembly of parts is not required and hand or tool tightening of nuts is not required on either the forward or rearward end. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the ferrule bushing 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 the retainer body of the liquid tight connector of the present invention. 
     FIG. 6 is an end view of the retainer body as viewed from the left side of FIG.  5 . 
     FIG. 7 is a plan view of the preferred embodiment of the present invention, a liquid tight connector consisting of an assemblage of the five separate portions. 
     FIG. 8 is a sectional view of the assembled retainer body cover, retainer body, and ferrule bushing of the present invention. 
     FIG. 9 is a perspective view showing a section of conduit, the assembled retainer body cover, retainer body, and ferrule bushing, the Santoprene washer, the snap-tight ring, and a junction box to which the connector will be fitted. 
     FIG. 10 is a side view showing the five portions of the preferred embodiment as they will be aligned prior to assemblage to form the liquid tight connector of the present invention and including, from left to right, the snap tight ring, the Santoprene washer, the ferrule bushing, the retainer body and the retainer body cover. 
     
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Part No. 
                 Part Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 20 
                 liquid tight connector 
               
               
                 22 
                 snap tight ring 
               
               
                 24 
                 washer 
               
               
                 26 
                 ferrule bushing 
               
               
                 28 
                 retainer body 
               
               
                 30 
                 retainer body cover 
               
               
                 32 
                 flange 
               
               
                 34 
                 forward end (of ferrule bushing) 
               
               
                 36 
                 rearward end (of ferrule bushing) 
               
               
                 38 
                 ferrule 
               
               
                 40 
                 rearward wall (of flange) 
               
               
                 42 
                 collar 
               
               
                 44 
                 threads (on collar) 
               
               
                 46 
                 end (of ferrule) 
               
               
                 48 
                 base (of ferrule) 
               
               
                 50 
                 nose 
               
               
                 52 
                 threaded shoulder (of nose) 
               
               
                 54 
                 hex surface (of flange) 
               
               
                 56 
                 seat 
               
               
                 58 
                 forward wall (of flange) 
               
               
                 60 
                 central bore (through ferrule bushing) 
               
               
                 62 
                 inner end (of retainer body cover) 
               
               
                 64 
                 outer end (of retainer body cover) 
               
               
                 66 
                 inner end (of retainer body) 
               
               
                 68 
                 outer end (of retainer body) 
               
               
                 70 
                 U-shaped cuts 
               
               
                 72 
                 inward directed tangs (of retainer body) 
               
               
                 74 
                 necked-down portion (of retainer body) 
               
               
                 76 
                 central bore (through retainer body) 
               
               
                 78 
                 wall (of retainer body) 
               
               
                 80 
                 outward tangs (on snap tight ring) 
               
               
                 82 
                 tapered outer periphery (of washer) 
               
               
                 84 
                 rearward wall (of collar) 
               
               
                 86 
                 interior threads (of retainer body cover) 
               
               
                 88 
                 free end (of inward directed tang) 
               
               
                 90 
                 conduit accepting channel 
               
               
                 92 
                 lip (on retainer body cover) 
               
               
                 94 
                 conduit 
               
               
                 96 
                 junction box 
               
               
                 98 
                 knockout aperture 
               
               
                 100 
                 forward end (of connector) 
               
               
                 102 
                 rearward end (of connector) 
               
               
                 104 
                 end (of conduit) 
               
               
                 106 
                 wall (of junction box) 
               
               
                   
               
             
          
         
       
     
    
    
     DESCRIPTION OF THE INVENTION 
     According to the present invention, five separate pieces are assembled as shown in FIG. 10 to form the preferred embodiment of the liquid tight connector  20 . The five pieces, including from left to right, the snap tight ring  22 , the washer  24 , the ferrule bushing  26 , the retainer body  28 , and the retainer body cover  30  are shown as they will be aligned prior to assemblage. 
     Referring to FIG. 1, a plan view of the ferrule bushing  26  shows a flange  32  dividing the bushing  26  into a forward end  34  and a rearward end  36 . The ends of the ferrule bushing  26  are labeled according to the direction they will eventually face when used in conjunction with a box or panel, with the forward end  34  being the end facing the panel and the rearward end  36  away from the panel. The rearward end  36  consists of a ferrule  38  extending from the rearward wall  40  of the flange. Also extending from the rearward wall  40  of the flange  32  is a collar  42  concentric with the ferrule  38 . The outer surface of the collar contains threads  44 . The ferrule  38  is narrow at its end  46  and tapers outward to a wider diameter near its base  48  toward the junction with the flange  32 . The forward end  34  of the ferrule bushing  26  includes a tubular nose  50  including a threaded exterior surface  52 . The exterior periphery of the flange has a hex surface  54 . 
     Referring now to FIG. 2, an end view of the ferrule bushing  26  is depicted as viewed from the right side of FIG.  1 . The tubular ferrule  38  is shown extending from the rearward wall  40  of the flange  32 . Outside of and concentric to the ferrule  38  is the collar  42  also extending from the rearward wall  40  of the flange. The surface of the rearward wall  40  between the ferrule  38  and the collar  42  includes a seat  56 . 
     As shown in FIG. 3, an end view of the ferrule bushing  26  as viewed from the left side of FIG. 1, the nose  50  extends from the forward wall  58  of the flange  32  and includes a threaded exterior surface  52 . The central bore  60  extends through the ferrule bushing  26 . 
     Referring now to FIG. 4, a plan view of the retainer body cover  30  depicts the cover  30  having an inner end  62  that will face the ferrule bushing  26  (not shown in FIG. 4) when the liquid tight connector is assembled and an outer end  64  that will face outward from the connector (not shown in FIG.  4 ). 
     Referring to FIG. 5, a plan view of the retainer body  28  depicts it having an inner end  66  that will face the ferrule bushing (not shown in FIG. 5) and an outer end  68 . U-shaped cuts  70  on the outer periphery of the retainer body  28  define inward directed tangs  72  that extend into the central bore through the tubular retainer body  28 . The retainer body  28  includes a necked-down portion  74  near the inner end  66 . 
     An end view of the retainer body  28 , as viewed from the left side of FIG. 5, is shown in FIG.  6 . The inward directed tangs  72  extend into the central bore  76  of the retainer body  28  from U-shaped cuts  70  in the wall  78  of the retainer body. 
     Referring to FIG. 7, a plan view is presented of the preferred embodiment of the present invention, a liquid tight connector  20  consisting of an assemblage of the five separate portions including the snap tight ring  22 , washer  24 , ferrule bushing  26 , retainer body cover  30 , and retainer body (covered by retainer body cover and therefore not in view in FIG.  7 ). The end  46  of the ferrule  38  is shown extending from the retainer body cover  30  on the left side of FIG. 7 with the flange  32  and its hex surface  54  toward the right of FIG.  7 . Outward tangs  80  on the snap tight ring  22  restrain the washer  24  on the nose  50  of the ferrule bushing  26 . The snap tight ring  22  may be held on the nose  50  by inward tangs (not shown in FIG. 7) that mate with the threaded shoulder  52  of the nose  50 . Further details of the snap tight ring 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, which describes a locking cable connector composed of three mating pieces that snap together and provide a connector for connecting helically wound armored or metal clad electrical conductors to junction boxes or electrical panels. The washer  24  typically has a tapered outer periphery  82 , with the wider portion of the taper oriented toward the flange  32 , as shown in FIG.  7 . 
     The interaction of three of the various pieces that form the preferred embodiment of the present invention are better understood by referring to the sectional view of the partially assembled liquid tight connector shown in FIG.  8 . The retainer body  28  slides over the ferrule  38  of the ferrule bushing  26  and the inner end  66  of the retainer body  28  contacts the rearward wall  84  of the collar  42 . The retainer body cover  30 , including interior threads  86  on its inner end  62 , slides over the retainer body  28  and is screwed onto the threads  44  on the collar  42  of the ferrule bushing  26  until the inner end  62  of the retainer body cover  30  contacts the rearward wall  40  of the flange  32 . Once the retainer body cover  30  is tightened on the collar  42  in this manner, the retainer body  28  is held concentrically around the ferrule  38  portion of the ferrule bushing  26  as shown in FIG.  8  and the lip  92  at the outer end  64  of the retainer body cover  30  holds the retainer body  28  within the retainer body cover  30 . The inward directed tangs  72  of the retainer body  28  include free ends  88  that are oriented toward the rearward wall  40  of the flange  32 . As shown in this cross-sectional view, the end  46  of the ferrule  38  gradually tapers upward in thickness toward the base  48 . A conduit-accepting channel  90  is created between the retainer body  28  and the retainer body cover  30 . The channel  90  is open at the rearward end  36  of the ferrule bushing  26  and is sized to accept a given trade size of conduit (not shown in FIG.  8 ). The inner extent of the channel includes a seat  56  defined by a portion of the rearward wall  84  of the collar  42 . 
     Referring to FIG. 9, the outer portion of the conduit-accepting channel  90  is visible in this perspective view showing a section of conduit  94 , the assembled retainer body cover  30 , retainer body (not visible in FIG.  9 ), and ferrule bushing  26 . The washer  24 , the snap tight ring  22 , and a junction box  96 , to which the connector  20  will be fitted at a knockout aperture  98 , are also shown. 
     Referring to FIG. 10, the rearward end  102  of the connector  20  would be assembled by sliding the inner end  66  of the retainer body  28  over the ferrule  38  until it contacts the rearward wall  84  of the collar  42 . The retainer body cover  30  would then be slid over the retainer body  28  until the interior threads (not visible in FIG. 10) of the retainer body cover  30  contacted the exterior threads  44  on the collar  42  and then screwed onto the collar  42  until the inner end  62  of the cover  30  is tightened against the rearward wall  40  of the flange. The forward end  100  of the connector, shown on the left side of FIG. 10, would be assembled by sliding the washer  24  over the nose  50  portion of the ferrule bushing  26  and then threading the snap tight ring  22  onto the threaded surface  52  of the nose  50 . Once tightened onto the nose  50 , the snap tight ring  22  would be tight against the forward wall  58  of the flange  32  and the outward tangs  80  of the snap tight ring  22  would hold the washer  24  against the forward wall  58 . 
     To put the liquid tight connector  20  of the present invention into service, the connector  20  would be provided with the five separate pieces, as shown in FIG. 10, completely assembled, as shown in FIG. 7 (retainer body obscured by retainer body cover and therefore not visible). 
     Referring to FIG. 9, once assembled, the liquid tight connector  20  is typically connected to a panel or junction box  96  by simply grasping a conduit  94  of the proper trade size, inserting it into the conduit-accepting channel  90  on the rearward end  102  of the connector, and pushing the conduit  94  into the channel  90  until the end  104  of the conduit is pushed flush against the seat (not visible in FIG. 9) at the end of the channel. After the conduit  94  is secured to the connector  20 , the forward end  100  of the connector  20  is pushed into the knockout aperture  98  of a junction box  96  until the outward tangs  80  clear the wall  106  of the junction box  96 . The snap tight ring  22  is constructed of a resilient material such as spring steel and the outward tangs  80  are oriented, in their unbiased position, outward from the outer periphery of the ring  22 . As the outward tangs  80  enter the knockout aperture  98  they are compressed inwardly. Further advancement of the snap tight ring  22  into the knockout aperture  98  eventually causes the outward tangs  80  to clear the wall  106  of the junction box  96  at which point the outward tangs  80  will snap back to their unbiased position. The outward tangs  80  then hold the connector  20  securely to the junction box  96 . 
     The water tight sealing nature of the connector is best explained by referring to the sectional view shown in FIG.  8 . The conduit-accepting channel  90  resides between the retainer body  28  and the retainer body cover  30  and is sized to accept a given trade size of conduit (not shown in FIG.  8 ). To install the connector, an installer would insert the proper trade size of conduit into the conduit-accepting channel  90  and push it therein. As the conduit advances from the end  46  to the base  48  of the ferrule  38 , the conduit envelops the ferrule  38  and forces the inward directed tangs  72  outward. Since the retainer body  28  and its inward directed tangs  72  are formed of a resilient material, the inward directed tangs  72  dig into the surface of the conduit and prevent it from being withdrawn. As the conduit advances farther into the conduit-accepting channel  90 , the end of the conduit (not shown in FIG. 8) is pushed onto the base  48  and the conduit is spread radially outward by the wider taper of the base  48 . Eventually the conduit is advanced to the end of the channel  90  where the end of the conduit contacts the seat  56 . The conduit is prevented from being withdrawn by the inward directed tangs  72  with the free end  88  of each tang digging into the surface of the conduit (not shown in FIG. 8 ). At its full insertion into the conduit-accepting channel  90  the inner circumference of the conduit is held tightly on its inside by the wider taper of the base  48  of the ferrule  38 , the end of the conduit is sealed tightly against the seat  56 , and the outer periphery of the end of the conduit is sealed by the inner periphery of the retainer body  28 . A water tight seal is therefore established between the rearward end  102  of the connector and the conduit. 
     Referring again to FIG. 9, after the conduit  94  has been inserted fully into the conduit-accepting channel  90  to create a water tight seal on the rearward end  102  of the connector  20 , the forward end  100  of the connector may be secured to a junction box or panel. The washer  24  is held against the forward wall  58  of the flange  32  by the outward tangs  80  on the snap tight ring  22 . The forward end  100  of the connector  20  is simply pushed into a knockout aperture  98  of a panel or a junction box  96 , as depicted in FIG.  9 . The snap tight ring  22 , being of a lesser diameter than the knockout aperture  98 , will easily enter the aperture  98 . As the snap tight ring  22  is constructed of a resilient material, the outward tangs  80 , extending to-a wider diameter than the knockout aperture  98 , are depressed as they enter the aperture  98 . Once they have cleared the wall  106  of the junction box  96 , the outward tangs  80  snap outwardly to their unbiased position, thereby locking the forward end  100  of the connector  20  against the junction box  96 . When the forward end  100  of the connector  20  is inserted into the knockout aperture  98 , the washer  24  is compressed, and as it is tapered with a narrower diameter toward the forward end  100  of the connector  20 , the forward portion of the washer  24  is forced into the open portion between the knockout aperture  98  and the nose  50 , thereby sealing the forward end  100  of the connector  20  and creating a water tight seal. When connected completely, with the conduit  94  inserted fully into the conduit-accepting channel  90  and the outward tangs  80  of the snap tight ring  22  engaged with the wall  106  of the junction box  96 , the washer  24  is forced into the knockout aperture  98  and the connector  20  is water tight on both its rearward  102  and forward  100  ends. 
     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 of the present disclosure can be constructed for any trade size of conduit by sizing the conduit-accepting channel  90 , 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  50 , snap tight ring  22 , and washer  24  can likewise be constructed of any desired size to enable rapid snap-in connection of the forward end  100  of the connector  20  to any trade size of knockout aperture  98 . 
     Referring again to FIG. 10, the pieces of the connector assembly  20  are, from left to right in FIG. 10, the snap tight ring  22 , the washer  24 , the ferrule bushing  26 , the retainer body  28 , and the retainer body cover  30 . The snap tight ring  22  is typically constructed of spring steel but may be constructed of any resilient metal or plastic. The washer  24  is typically constructed of Santoprene™, which is a trademark of Advanced Elastomer Systems, L.P., but may be constructed of any similar thermoplastic elastomer. Additionally, it may be preferable to construct the 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 nylon or PVC for non-metallic conduit. If the connector were constructed for metallic conduit, then the ferrule bushing would typically be constructed or zinc, or a similar metal to enable the connector to establish electrical continuity between the metallic conduit and the panel or junction box. The retainer body  28  and the retainer body cover  30  could be constructed of any appropriate metal or plastic, but preferably would be constructed of nylon or PVC. 
     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.