Abstract:
An improved liquid-tight connector that simplifies and vastly reduces the time and effort in securing non-metallic or metallic conduit to panels, junction boxes, or similar devices. The connector does not require a nut to secure its leading end to a panel or a compression nut to secure its trailing end to a conduit as is typically required with conventional liquid-tight connectors. The need to tighten nuts by hand or with hand tools is therefore eliminated. The connector allows connection of conduit to panels without the need to disassemble a portion of the connector and then reassemble again as in many prior art devices. The connector allows an installer to create a liquid-tight connection between a conduit and a panel by simply pushing a conduit into the trailing end of the connector and pushing the leading end of the connector into an aperture in the 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 designed for use with either metallic or non-metallic conduit. If desired, a snap locking ring may be removed from the leading end of the connector to allow it to be screwed into a threaded access hole, or to be connected to a smooth access hole in the panel with a lock nut, similar to a conventional fitting.

Description:
This application is a Continuation of U.S. patent application Ser. No. 10/115,316 entitled “Electrical Connector”, filed Mar. 28, 2002 now U.S. Pat. No. 6,642,451 and which is a Continuation-In-Part of U.S. patent application Ser. No. 10/017,537 entitled “Liquid-tight Connector”, filed Oct. 22, 2001 and now U.S. Pat. No. 6,616,194 and also a Continuation-In-Part of U.S. patent application Ser. No. 10/034,156 entitled “Threaded Snap In Connector”, filed Dec. 26, 2001 and now U.S. Pat. No. 6,538,201, all of which are referred to herein and incorporated by reference. 

   FIELD OF THE INVENTION 
   The present invention relates to devices for connecting electrical tubing or conduit to electrical panels or junction boxes and specifically to a device that is liquid-tight, adaptable for snap-in or threaded connection to a panel, and easier to use than current connectors that are commonly used in the trade. 
   BACKGROUND OF THE INVENTION 
   Liquid-tight connectors are commonly used in the electrical industry for providing a liquid-tight connection between electrical conduit and panels or junction boxes. These connectors are usually multi-piece devices in which a portion 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 leading 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 above an annular ring on a ferrule. To fit the conduit into the liquid-tight connector of the &#39;068 patent, the installer must insert the conduit into the fitting, and then tighten a compression nut with a hand tool such as a wrench to close the fingers on the clip and thereby achieve a liquid-tight fit. The leading 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 trailing end of the fitting, between the conduit and the fitting, and on the leading 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 trailing end of the fitting. The gland nut must be removed from the connector body and then is inserted over an electrical conduit with the outer surface of the conduit being received through the centrally located bore of the gland nut. The conduit is then pushed onto a ferrule. 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 leading end of the fitting in the &#39;072 patent is typically threaded and requires the use of a nut and an O-ring to secure the fitting to the panel and 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 partially or completely disassembled at the jobsite prior to insertion of the conduit and then reassembled after the conduit is inserted into the trailing 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 trailing end between the conduit and the connector. 
   (c) The leading end of prior art liquid-tight connectors for electrical 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 sealing ring or O-ring is typically provided with prior art liquid-tight conduit connectors and must be assembled onto the leading end of the connector prior to insertion of the leading end into the knock-out on a panel or box. 
   SUMMARY OF THE INVENTION 
   The present invention combines the advantages of the improved liquid-tight connector of U.S. patent application Ser. No. 10/017,537, filed Oct. 22, 2001 with the advantages of the threaded snap in connector of U.S. patent application Ser. No. 10/034,156, filed Dec. 26, 2001. Both of these references are incorporated herein by reference. U.S. patent Ser. No. 10/017,537 provided a liquid-tight connector assembly that may be simply installed by pushing a conduit into a channel on the trailing end of the connector and then pushing the leading end of the connector into a knock-out in a panel until outward projecting tangs on an annular steel spring adapter snap into place and create a liquid-tight fit. The steel spring adapter required that the leading end of the connector be threaded. U.S. patent Ser. No. 10/034,156 provided an improved connector with a threaded leading end and an improved snap ring that could be fitted on the leading end of the connector to provide a quick snap-tight connection to a knockout in a panel or could be removed to allow the connector to be screwed into a threaded access hole in a panel. The present invention therefore combines the versatility of the improved snap ring with the easy-insertion liquid-tight connector. 
   The present 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 body with an axial bore there through and a centrally located flange dividing it into two ends including a leading end having threads on its exterior surface and a trailing end having an extending ferrule. A snap ring and a sealing ring are included on the leading end. Inward facing tabs on the leading end of the snap ring fit into a depression of the leading end of the connector thereby securing the snap ring to the connector. The trailing end of the connector 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 trailing end by the retainer body cover that is screwed onto a threaded shoulder extending from the central flange. The sealing ring is held on the leading end of the connector by outward projecting grounding tangs on the snap ring. 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 trailing end of the connector and then pushing the leading 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 leading or trailing end. If it is desired to connect a conduit to a panel through a threaded access hole, the snap ring may be easily removed and the connector may be secured by screwing the leading end into the threaded hole. 
   Other advantages of the present invention will be better understood from the following descriptions when read in conjunction with the appropriate drawings. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a plan view of the tubular body of the liquid-tight connector of the present invention. 
       FIG. 2  is a detailed view of a corner of the leading end portion of the tubular body of  FIG. 1 . 
       FIG. 3  is an end view of the retainer body cover as viewed from the right side of  FIG. 4 . 
       FIG. 4  is a plan view of the retainer body cover portion of the liquid-tight connector of the present invention. 
       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 right 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 tubular body of the present invention. 
       FIG. 9  is a plan view of the blank used to form the snap ring of the present invention. 
       FIG. 10  is an end view of the annular snap ring formed from the blank shown in  FIG. 9 . 
       FIG. 11  is a sectional view taken on section  11 — 11  of  FIG. 10 . 
       FIG. 12  is a perspective view of the annular snap ring of  FIG. 11  with the trailing end on the right. 
       FIG. 13  is a exploded 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 ring, the Santoprene sealing ring, the tubular body, the retainer body and the retainer body cover. 
       FIG. 14  is a perspective view showing the manner in which the various portions of the liquid-tight connector of the present invention are oriented and aligned prior to connection to a junction box. 
       FIG. 15  is a sectional view of the leading end of the liquid-tight connector taken on section  15 — 15  of  FIG. 7 . 
       FIG. 16  is a sectional view of the leading end of an alternative embodiment of the liquid-tight connector having a smooth nose portion on the tubular body. 
       FIG. 17  is a plan view of a preferred embodiment of the sealing ring used to achieve a liquid-tight seal between the leading end of the connector and a panel or junction box. 
       FIG. 18  is a sectional view taken on section  18 — 18  of the sealing ring shown in  FIG. 17 . 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Table of Nomenclature 
               
             
          
           
               
                   
                 Part No. 
                 Part Description 
               
               
                   
                   
               
               
                   
                  20 
                 liquid-tight connector 
               
               
                   
                  22 
                 snap ring 
               
               
                   
                  24 
                 sealing ring 
               
               
                   
                  26 
                 tubular body 
               
               
                   
                  28 
                 retainer body 
               
               
                   
                  30 
                 retainer body cover 
               
               
                   
                  32 
                 flange 
               
               
                   
                  34 
                 leading end (of tubular body) 
               
               
                   
                  36 
                 trailing end (of tubular body) 
               
               
                   
                  38 
                 ferrule 
               
               
                   
                  40 
                 trailing wall (of flange) 
               
               
                   
                  42 
                 shoulder 
               
               
                   
                  44 
                 threads (on shoulder) 
               
               
                   
                  46 
                 end (of ferrule) 
               
               
                   
                  48 
                 base (of ferrule) 
               
               
                   
                  50 
                 nose portion 
               
               
                   
                  54 
                 depression 
               
               
                   
                  56 
                 leading edge (of nose portion) 
               
               
                   
                  58 
                 threads (on exterior of nose portion) 
               
               
                   
                  60 
                 hex surface 
               
               
                   
                  62 
                 leading side wall 
               
               
                   
                  64 
                 trailing side wall 
               
               
                   
                  66 
                 bottom 
               
               
                   
                  68 
                 leading end of retainer body cover 
               
               
                   
                  70 
                 trailing end of retainer body cover 
               
               
                   
                  72 
                 lip (on retainer body cover) 
               
               
                   
                  74 
                 leading end (of retainer body) 
               
               
                   
                  76 
                 trailing end (of retainer body) 
               
               
                   
                  78 
                 U-shaped cuts 
               
               
                   
                  80 
                 inward and forward extending conduit tangs 
               
               
                   
                  82 
                 central bore (of retainer body) 
               
               
                   
                  84 
                 necked-down portion (of retainer body) 
               
               
                   
                  86 
                 wall (of retainer body) 
               
               
                   
                  88 
                 interior threads (on retainer body cover) 
               
               
                   
                  90 
                 free end of conduit tangs 
               
               
                   
                  92 
                 channel 
               
               
                   
                  94 
                 seat 
               
               
                   
                  96 
                 trailing wall of shoulder 
               
               
                   
                 100 
                 blank 
               
               
                   
                 102 
                 tongue 
               
               
                   
                 104 
                 groove 
               
               
                   
                 106 
                 U-shaped openings 
               
               
                   
                 108 
                 snap locking tangs 
               
               
                   
                 110 
                 wide slots 
               
               
                   
                 112 
                 shear line 
               
               
                   
                 114e 
                 first edge of blank 
               
               
                   
                 114 
                 leading end of snap ring 
               
               
                   
                 116e 
                 second edge of blank 
               
               
                   
                 116 
                 trailing end of snap ring 
               
               
                   
                 118 
                 slits 
               
               
                   
                 120 
                 grounding tangs 
               
               
                   
                 122 
                 outer circumference (of snap ring) 
               
               
                   
                 124 
                 locking tab (of snap ring) 
               
               
                   
                 126 
                 face 
               
               
                   
                 128 
                 locking tab segments 
               
               
                   
                 130 
                 space between segments 
               
               
                   
                 132 
                 abutment or outer edges (of snap locking tangs) 
               
               
                   
                 134 
                 inner circumference of snap ring 
               
               
                   
                 136 
                 inner edges of locking tab 
               
               
                   
                 138 
                 area free of segments 
               
               
                   
                 140 
                 junction box 
               
               
                   
                 142 
                 knockout or access hole 
               
               
                   
                 144 
                 leading end of connector 
               
               
                   
                 146 
                 trailing end of connector 
               
               
                   
                 148 
                 conduit 
               
               
                   
                 150 
                 junction box wall 
               
               
                   
                 152 
                 leading wall of flange 
               
               
                   
                 154 
                 outer surface of junction box wall 
               
               
                   
                 156 
                 inner surface of junction box wall 
               
               
                   
                 158 
                 end of conduit 
               
               
                   
                 160 
                 side walls of access hole 
               
               
                   
                 162 
                 grounding edge (of grounding tang) 
               
               
                   
                 164 
                 central axis 
               
               
                   
                 166 
                 outer edge of sealing ring 
               
               
                   
                 168 
                 inner edge of sealing ring 
               
               
                   
                 170 
                 base portion of sealing ring 
               
               
                   
                 171 
                 outer portion of sealing ring 
               
               
                   
                 172 
                 leading face of outer portion 
               
               
                   
                 174 
                 trailing face of outer portion 
               
               
                   
                 176 
                 leading face of base portion 
               
               
                   
                 178 
                 trailing face of base portion 
               
               
                   
                 180 
                 base thickness 
               
               
                   
                 182 
                 outer thickness 
               
               
                   
                 184 
                 second embodiment of liquid-tight connector 
               
               
                   
                 186 
                 smooth outer periphery (of nose portion) 
               
               
                   
                   
               
             
          
         
       
     
   

   DESCRIPTION OF THE INVENTION 
   According a preferred embodiment of the present invention, five separate pieces are assembled as shown in  FIG. 13  to form the preferred embodiment of the liquid-tight connector  20 . The five pieces include, from left to right, the snap ring  22 , sealing ring  24 , tubular body  26 , retainer body  28 , and retainer body cover  30 . 
   With reference to  FIG. 1 , a plan view of the tubular body  26  depicts a flange  32  dividing the tubular body  26  into a leading end  34  and a trailing end  36 . The ends of the tubular body  26  are labeled according to the direction they will eventually face when used in conjunction with a junction box or panel, with the leading end  34  being the end facing the panel and the trailing end  36  away from the panel. The trailing end  36  consists of a ferrule  38  extending from the trailing wall  40  of the flange. Also extending from the trailing wall  40  of the flange  32  is a shoulder  42  concentric with the ferrule  38 . The outer surface of the shoulder 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 leading end  34  of the tubular body  26  includes a tubular nose portion  50  with a depression  54  near its leading edge  56  and a threads  58  on its exterior surface. The exterior periphery of the flange has a hex surface  60 . 
   Referring now to  FIG. 2 , a detailed view of a corner of the leading end portion of the tubular body  26  shows the depression  54  in greater detail. The depression  54  is composed of a leading side wall  62 , a trailing side wall  64 , and a bottom  66  that encircles the entire periphery of the nose portion  50 . 
   Referring to  FIG. 4 , a plan view of the retainer body cover  30  depicts the cover  30  having a leading end  68  that will face the tubular body (not shown in  FIG. 4 ) when the liquid-tight connector is assembled and a trailing end  70  that will face outward from the connector (not shown in  FIG. 4 ). 
   As shown in  FIG. 3 , an end view of the retainer body cover  30  as viewed from the leading end  68 , the trailing end includes a lip  72  that will bear against the retainer body (not shown) when the connector is assembled and secure the retainer body to the tubular body. 
   Referring now to  FIGS. 5 and 6 , the retainer body  28  includes a leading end  74  that will face the tubular body and a trailing end  76 . U-shaped cuts  78  on the outer periphery of the retainer body  28  define inward and forward extending conduit tangs  80  that extend into the central bore  82  of the tubular retainer body  28 . The retainer body  28  includes a necked-down portion  84  near the leading end  74 . The inward and forward extending conduit tangs  80  extend into the central bore  82  of the retainer body  28  from U-shaped cuts  78  in the wall  86  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 ring  22 , sealing ring  24 , tubular body  26 , retainer body cover  30 , and retainer body (covered by retainer body cover and therefore not in view in  FIG. 7 ). The trailing end  146  of the connector  20 , depicted on the right side of  FIG. 7 , shows the end of the ferrule  38  extending from the retainer body cover  30 . Grounding tangs  120  on the snap ring  22  restrain the sealing ring  24  on the nose portion  50  of the tubular body  26 . Inward bent locking tabs (not shown in  FIG. 7 ) fit into the depression  54  located near the leading edge  56  of the nose portion  50  and thereby secure the snap ring  22  to the tubular body  26 . The sealing ring  24  is held on the nose portion  50  of the connector  20  by the grounding tangs  120 . 
   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 . Depicted in this drawing are the assembled retainer body cover  30 , retainer body  28 , and tubular body  26 . To assemble these components, the retainer body  28  is positioned over the ferrule  38  of the tubular body  26  until the leading end  74  of the retainer body  28  contacts the trailing wall  96  of the shoulder  42 . The retainer body cover  30 , including interior threads  88  on its leading end  74 , slides over the trailing end  76  of the retainer body  28  and is screwed onto the threads  44  on the shoulder  42  of the tubular body  26  until the leading end  68  of the retainer body cover  30  contacts the trailing wall  40  of the flange  32 . After the retainer body cover  30  is tightened on the shoulder  42  in this manner, the retainer body  28  is held concentrically around the ferrule  38  portion of the tubular body  26  as shown in  FIG. 8  and the lip  72  at the trailing end  70  of the retainer body cover  30  holds the retainer body  28  within the retainer body cover  30 . The inward and forward extending conduit tangs  80  of the retainer body  28  include free ends  90  that are oriented toward the trailing wall  40  of the flange  32 . As shown in this cross-sectional view, the ferrule  38  gradually tapers upward in thickness from its end  46  toward its base  48 . A conduit-accepting channel  92  is created between the inner circumference of the retainer body  28  and the outer circumference of the ferrule  38 . The channel  92  is open at the trailing end  36  of the tubular body  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  94  defined by a portion of the trailing wall  96  of the shoulder  42 . 
   With reference to  FIG. 9 , there is shown a plan view of the blank  100  used to form the snap ring. The blank  100  is typically stamped from a thin piece of spring steel, such as 1050 spring steel or equivalent, preferably approximately 0.020 inches in thickness plus a zinc plating of 0.00015 inches thick but may be 0.013 to 0.023 inches in thickness. The blank  100  has a tongue  102  on one end and a groove  104  on the opposite end. U-shaped openings  106  in the blank  100  define snap locking tangs  108  that are lanced from the body of the blank. The U-shaped openings  106  have relatively wide slots  110  on each side of the tangs and a slot or shear line  112  at the bottom of the U-shape. The blank  100  includes two edges  114   e ,  116   e , which will become the leading  114  and trailing  116  ends of the snap ring after the blank  100  is formed into its annular shape. The snap locking tangs  108  are bent outwardly and toward the trailing edge  116   e . Two slits or narrow openings  118  in blank  100  adjacent the trailing edge  116   e  define grounding tangs  120  that will be bent outward and toward the trailing edge  116   e . The flat front surface of blank  100  shown in  FIG. 9  will become the outer circumference  122  when it is formed into the annular-shaped snap ring. One or more locking tabs  124 , creating a series of locking tab segments  128 , are typically formed in the leading edge  114   e  of the blank as shown. One continuous locking tab may be formed along the leading edge of the blank, if desired, in lieu of a series of locking tab segments. 
   With reference to  FIGS. 9 and 14 , after the snap ring blank is formed into its annular shape, edge  114   e  becomes the leading end  114  of the annular-shaped snap ring  22  facing into the interior of a junction box and edge  116   e  becomes the trailing end  116  facing away from the interior of the junction box. 
     FIG. 10  depicts an end view of blank  100  after it has been formed into a circle or annular shape. Snap locking tangs  108  are angled outwardly and trailingly from face  126 . The grounding tangs  120  are angled outwardly and trailingly. The locking tab segments  128  are bent inward at approximately right angles to the outer circumference. 
     FIG. 11  depicts a cross section of the snap ring  22  taken along lines  11 — 11  of  FIG. 10  with the snap locking tangs and grounding tangs omitted. As shown in  FIGS. 10 and 12 , the locking tab  124  may be segmented into individual locking tab segments  128  with the space  130  between segments partly closed when bent into a locking tab  124 . 
   When blank  100  is formed into an annular shape, tongue  102  loosely fits into groove  104 . The blank formed into an annular snap ring  22  is depicted in  FIGS. 10 and 12 . Usually, the spring steel is heat treated after the forming operation so that the steel will have the correct properties and so that it will hold the annular shape. The blank  100  for a ½ inch trade size is approximately 0.548 inches wide and 2.750 inches long prior to being formed in the annular shape. Snap locking tangs  108  with outer or abutment edges  132  extend and are angled outwardly and trailingly from the outer circumference  122  of the snap ring  22  and are located preferably at approximately 180 degrees from each other. 
   The snap locking tangs form an outermost diameter of approximately 1.0 inch for a ½ trade size connector. Except when specifically indicated otherwise herein, all dimensions are with reference to a ½-inch trade size fitting. 
   The locking tab  124  extends inwardly from the inner circumference  134  at the approximate angle shown which is approximately a right angle to form an inner diameter of approximately 0.605 inch as measured at the inner edge  136  of the locking tab  124 . 
   Referring to  FIG. 15 , the inner edge  136  of locking tab  124  drops into the depression  54  so that the inner edge  136  contacts the bottom  66  of the depression. The depression  54  has a leading wall  62  and a trailing side wall  64  with the depression being approximately 0.060 inch wide and is approximately 0.055 inch deep. The depression  54  is near the leading end  144  of the connector  20  and is preferably spaced approximately 0.110 inch from the end. This prevents the snap ring  22  from linear leading movement with respect to the connector thus. The snap ring  22  is therefore locked onto the connector unless the locking tab  124  is raised out of the depression  54  by an installer&#39;s fingers or by the use of a simple prying tool, such as a screwdriver. 
   As seen in  FIGS. 10 and 12 , the number of individual segments  128  in the preferred embodiment of the snap ring  22  is 12. The segments  128  extend circumferentially approximately 270° with an area  138  free of segments extending over the area covered by the tongue  102  and groove  104 . 
   Details of the sealing ring  24  are shown in the plan view of  FIG. 17  and the cross-sectional view of  FIG. 18 . The annular-shaped sealing ring  24  has an outer edge  166  and an inner edge  168  with a base portion  170  adjacent to the inner edge and an outer portion  171  extending from the base portion  170 . As shown in the cross-sectional view of  FIG. 18 , the sealing ring  24  is shaped somewhat like a saucer, with the base portion  170  in a flat plane and the outer periphery extending at an approximate 50° angle from the base. The cross-sectional view also shows the various sealing surfaces on the sealing ring  24  including a leading sealing face  172  and a trailing sealing face  174  on the outer portion  171  and a leading sealing face  176  and a trailing sealing face  178  on the base portion  170 . The base thickness, designated by reference numeral  180 , is not as thick as the outer perimeter  182 . As shown in the cross-sectional view of  FIG. 18 , the sealing ring  24  increases in thickness  180  from the base portion  170  to the thickness  182  at the outer portion  171 . 
   To understand the operation of the present invention, refer to  FIG. 14 , which is a perspective view showing the manner in which the various portions of the liquid-tight connector  20  are oriented and aligned prior to connection to a junction box  140 . Although  FIG. 14  depicts the sealing ring  24  and snap ring  22  exploded away from the main body of the connector  20 , typically the connector would be supplied in one piece with the five separate portions assembled. The user would have the option of applying the assembled connector  20  to a smooth access or knock-out hole  142  as shown, or could install the connector to a threaded access hole (not shown) by removing the snap ring  22  and screwing the connector  20  with the externally threaded nose portion  50  into the internal threads of the threaded access hole. In either case, the sealing ring  24  is used to achieve a liquid-tight fit between the connector  20  and the box  140 . If the snap ring  22  is removed for connection to a threaded access hole, the snap ring is removed and the sealing ring  24  retained. If the connector  20  is connected to a box at a knockout aperture as shown, the snap ring  22  is retained on the nose portion  50  and the grounding tangs  120  hold the sealing ring  24  in place. The snap ring  22  is held on the nose portion  50  of the connector  20  by the locking tab segments  128  extending into the depression  54  on the leading end  144  of the connector. 
   Referring to  FIG. 14 , as the connector  20  and snap ring  22  are pushed into the access hole or knock-out  142 , the snap locking tangs  108  are forced inward toward the central axis  164  of the annular snap ring  22 . The spring steel material of construction of the snap ring  22  allows the snap locking tangs  108  to flex inwardly toward the central axis  164 . When the snap ring  22  is advanced sufficiently into the access hole  142 , the snap locking tangs  108  spring outward as their abutment edges  132  pass completely through the electrical junction box wall  150 . As a result, the connector  20  is locked tightly into place on each side of the wall  150  between the leading wall  152  of flange  32  of the connector  20  on one side abutted with the outer surface  154  of the junction box wall  150  and the snap locking tangs  108  abutted with their abutment edges  132  against the inner surface  156  of the junction box wall  150 . 
   Referring to  FIG. 13 , the trailing end  146  of the connector  20  is assembled by sliding the leading end  74  of the retainer body  28  over the ferrule  38  until it contacts the trailing wall  96  of the shoulder  42 . The retainer body cover  30  would then be slid over the retainer body  28  until the interior threads (not visible in  FIG. 13 ) of the retainer body cover  30  contacted the exterior threads  44  on the shoulder  42  and then screwed onto the shoulder  42  until the leading end  68  of the cover  30  is tightened against the trailing wall  40  of the flange. The leading end  34  of the tubular body  26  will become the leading end  144  of the connector after the separate pieces are assembled. The connector is assembled by sliding the sealing ring  24  over the nose portion  50  of the tubular body  26  and pushing the snap ring  22  onto the nose portion  50  until the locking tabs  124  (not shown) of the snap ring  22  snap into the depression  54 . Once tightened onto the nose portion  50 , the snap ring  22  would extend nearly to the leading wall  152  of the flange  32  and the grounding tangs  120  of the snap ring  22  would hold the sealing ring  24  against the leading wall  152  of the flange  32 . 
   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. 13 , completely assembled, as shown in  FIG. 7  (retainer body obscured by retainer body cover and therefore not visible). 
   Referring to  FIG. 14 , once assembled, to operate the present invention, the liquid-tight connector  20  is typically connected to a panel or junction box  140  by simply grasping a conduit  148  of the proper trade size, inserting it into the channel  92  on the trailing end  146  of the connector  20 , and pushing the conduit  148  into the channel  92  until the end  158  of the conduit  148  is pushed flush against the seat (not visible in  FIG. 14 ) at the end of the channel. After the conduit  148  is secured to the connector  20 , the leading end  144  of the connector  20  is pushed into the access hole  142  of a junction box  140  until the snap locking tangs  108  clear the wall  150  of the junction box  140 . The snap ring  22  is constructed of a resilient material such as spring steel and the snap locking tangs  108  are oriented, in their unbiased position, outward and trailingly from the outer periphery of the ring  22 . As the snap locking tangs  108  enter the access hole  142  they are compressed inwardly. Further advancement of the snap ring  22  into the access hole  142  eventually causes the snap locking tangs  108  to clear the wall  150  of the junction box  140  at which point the snap locking tangs  108  will snap back to their unbiased position. The snap locking tangs  108  then hold the connector  20  securely to the junction box  140 . Therefore, the liquid-tight connector of the present invention is very easy to install compared to prior art connectors, as no hand or tool tightening of nuts on the leading end or compression nuts on the trailing end is required to achieve good continuity and a liquid-tight fit. As shown by the above description, all that is required to install the present invention is to push the conduit firmly into the channel on the trailing end of the connector and then push the leading end of the connector into a knockout hole until the snap locking tangs  108  pass the inner wall of the junction box and snap outward. 
   When installed in a junction box, as simulated in  FIG. 14 , the leading edge  114  of the snap ring  22  will reside inside the junction box  140 , and the outer or trailing edge  116  is within the confines or side walls  160  of the access hole  142 . The grounding tangs  120  extend outward approximately 0.052 inches and are forced inward by the inside wall of access hole  142  so that the trailing grounding edge  162  of the grounding tangs make firm contact within the side walls of the access hole  142 . Thus, the side walls  160  serve to encircle the trailing edge  116  to assist in keeping the annular snap ring  22  from expanding outward. The connector is highly resistive to pull out forces when the connector  20  and snap ring  22  are locked in place. 
   The water tight sealing nature on the trailing end of the connector is best explained by referring to the sectional view of the assembled tubular body  26 , retainer body  28 , and retainer body cover  30  shown in  FIG. 8 . The conduit-accepting channel  92  resides at the trailing end  36  of the tubular body  26  between the inner circumference of the retainer body  28  and the outer circumference of the ferule  38  and is sized to accept a given trade size of conduit (not shown in  FIG. 8 ). To install the connector, an installer would simply insert the proper trade size of conduit into the conduit-accepting channel  92  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 and forward extending conduit tangs  80  outward. Since the conduit tangs  80  are pressured inward by the retainer body cover  30 , the sharp free ends  30  of the conduit tangs  80  dig into the surface of the conduit and prevent it from being withdrawn. As the conduit advances farther into the conduit-accepting channel  92 , the end of the conduit (not shown in  FIG. 8 ) is pushed onto the base  48  of the ferrule  38  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  92  where the end of the conduit contacts the seat  94 . The conduit is prevented from being withdrawn by the inward and forward extending conduit tangs  80  with the free end  90  of each tang digging into the surface of the conduit (not shown in  FIG. 8 ). At its full insertion into the conduit-accepting channel  92  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  94 , and the outer periphery of the end of the conduit is sealed by the inner periphery of the retainer body  28 . A water or liquid tight seal is therefore established between the trailing end  146  of the connector and the conduit. 
   Referring to  FIG. 14 , after the conduit  148  has been inserted fully into the conduit-accepting channel  92  to create a water tight seal on the trailing end  146  of the connector  20 , the leading end  144  of the connector may be secured to a junction box  140  or panel. The sealing ring  24  is held against the leading wall  152  of the flange  32  by the grounding tangs  120  on the snap ring  22 . The leading end  144  of the connector  20  is simply pushed into an access hole  142  of a panel or a junction box  140 , as depicted in  FIG. 14 . The snap ring  22 , being of a lesser diameter than the access hole  142 , will easily enter the aperture. As the snap ring  22  is constructed of a resilient material, the snap locking tangs  108 , extending to a wider diameter than the access hole  142 , are depressed as they enter the aperture. Once they have cleared the wall  150  of the junction box  140 , the snap locking tangs  108  snap outwardly to their unbiased position, thereby locking the leading end  144  of the connector  20  against the junction box  140 . When the leading end  144  of the connector  20  is inserted into the access hole  142 , the sealing ring  24  is compressed and forced into the open portion between the access hole  142  and the nose portion  50 , thereby sealing the leading end  144  of the connector  20  and creating a water tight seal. When connected completely, with the conduit  148  inserted fully into the channel  92  and the snap locking tangs  108  of the snap ring  22  engaged with the wall  150  of the junction box  140 , the sealing ring  24  is forced into the access hole  142  and the connector  20  is water or liquid tight on both its trailing  146  and leading  144  ends. 
   The sealing capability of the sealing ring  24  can be better understood by referring to  FIG. 15 , a sectional view of the leading end of the liquid-tight connector taken on section  15 — 15  of  FIG. 7 . As shown in  FIG. 15 , after the snap ring  22  is snapped onto the nose portion  50 , the grounding tangs  120  of the snap ring  22  hold the sealing ring  24  in place with the trailing end  116  of the snap ring compressing the inner edge  168  of the base portion  170  of the sealing ring and also working in conjunction with the grounding tangs  120  to hold the sealing ring  24  in place. When the leading end  144  of the connector is pushed into an aperture in a panel (not shown), the sealing ring  24  is compressed between the leading wall  152  of the flange  32  and the outer face (not shown) of the panel. A water-tight seal is created between several surfaces, including the leading face  176  of the base portion  170  of the sealing ring  24  against the trailing end  116  of the snap ring  22 , the trailing face  178  of the base portion  170  of the sealing ring  24  against the leading wall  152  of the flange  32 , the leading face  172  of the outer portion  171  of the sealing ring  24  against the outer wall of the panel (not shown), and the trailing face  174  of the outer portion  171  of the sealing ring  24  against the leading wall  152  of the flange  32 . The design of the sealing ring  24 , including the differing thickness between the base thickness  180  and outer thickness  182 , is critical to achieving a water-tight seal at the leading end  144  of the connector. The larger thickness  182  at the outer portion  171  allows the sealing ring  24  to form a tight seal at the outer portion  171  of the sealing ring  24  and thereby creating a liquid-tight seal near the outer periphery of the connector after it is attached to the panel. The smaller thickness  180  at the base portion  170  allows the sealing ring  24  to form an additional seal at the inner periphery  168  of the sealing ring  24 . The design of the sealing ring and its material of construction therefore contribute to an excellent liquid-tight fit at the juncture of the connector and the junction box or panel. 
   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  92 , 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  50 , snap ring  22 , and sealing ring  24  can likewise be constructed of any desired size to enable rapid snap-in connection of the leading end  144  of the connector  20  to any trade size of access hole  142 . 
   Referring again to  FIG. 13 , the pieces of the connector assembly  20  are, from left to right in  FIG. 13 , the snap ring  22 , the sealing ring  24 , the tubular body  26 , the retainer body  28 , and the retainer body cover  30 . The snap ring  22  is typically constructed of spring steel but may be constructed of any resilient metal or plastic. The sealing ring  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 sealing ring  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 tubular body is preferably constructed of nylon, polycarbonate, or PVC for non-metallic conduit. If the connector were constructed for metallic conduit, the tubular body would typically be constructed of 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 polycarbonate, nylon, or PVC. 
   The outer diameter of the annular snap lock ring  22  in its relaxed or unbiased shape, as best shown in  FIG. 10 , is preferably circular and, as measured from its outer surface  122 , is approximately 0.845 inches in diameter for ½-inch nominal trade size threads. The dimensions of the snap ring  22  mentioned herein are for use with a threaded connector having ½ inch NPS (National Pipe Straight) or NPT (National Pipe Taper) trade size thread. 
   The nominal knockout or access hole for an electrical junction box is 0.875 inches in diameter. Usually the manufacture provides an opening 0.870 to 0.880 inches in diameter. However, the access hole can be as small as 0.859 inches in diameter (including tolerances). 
   The snap ring could be constructed for other standard trade size threads by scaling these dimensions including truncating appropriate to the nominal trade sizes such as for nominal trade sizes ¾ inch or 1 inch. 
   The nominal major diameter of the threads  58  on the outer circumference of the nose portion  50  is normally approximately 0.805 to 0.808 inches, but the threads can be truncated to an approximate major diameter of 0.795 inch. This leaves sufficient space between the major truncated diameter and the minimum diameter of 0.859 inches for the access hole to accommodate the thickness of the wall of the snap ring. 
   The tongue  102  and groove  104 , as best seen in  FIG. 12 , are designed so that there is a minimum fit between the tongue and groove from side to side and the groove and tongue are generally rectangular in shape and not tapered. This helps to prevent the snap locking or snap ring  22  from being entangled when a number of them are in loose fashion prior to assembly. 
   A surface of a leading end portion being tapered from a small diameter at the leading edge is 0.600 inch to a larger diameter is 0.720 inch at a side wall near said leading edge, an outer diameter of a leading end portion of a tubular body is 0.790 to 0.810 inch for a ½-inch nominal trade size fitting, a depression is from 0.023 to 0.060 inch wide and 0.010 to 0.055 inch deep as measured from minor thread diameter of a nominal trade size threads, a leading end portion has an outer diameter of 0.805 to 0.808 inch, a depression is from 0.023 to 0.060 inch wide and 0.010 to 0.055 inch deep as measured from said outer periphery of a leading end portion, a locking tab extends 0.057 to 0.122 inch from an outer diameter of an annular-shaped snap ring, a snap ring is constructed of spring steel with a thickness of 0.013 to 0.023 inch and more preferably with a thickness of 0.017 to 0.023 inch, the outer diameter of an annular-shaped snap ring is 0.805 to 0.860 inch for a ½-inch nominal trade size fitting, an inner diameter of an annular-shaped snap ring is 0.805 to 0.810 inch for a ½-inch nominal trade size fitting, each of grounding tangs in their unbiased states extend 0.015 to 0.060 inch beyond the outer diameter of a snap ring for a ½-inch nominal trade size fitting, nominal trade size threads include a major diameter of 0.805 to 0.808 inch, a pitch diameter of 0.751 to 0.754 inch, and a minor diameter of 0.710 to 0.713 inch for a ½-inch nominal trade size fitting, and an outer diameter measured across grounding tangs is 0.865 to 0.965 inch for a ½-inch nominal trade size fitting. 
   Referring to  FIG. 16 , a sectional view is shown of an alternative embodiment of the leading end  144  of a liquid-tight connector  184  having a smooth outer periphery  186  on the nose portion  50  of the tubular body  26 . The snap ring  22  is secured on the smooth outer periphery  186  of the nose portion  50  by first simply placing the snap ring  22  over the smaller diameter leading edge  56  of the nose portion  50 . The ring  22  can then be spread slightly by grasping the tongue  102  and groove  104  and pulling apart. The snap ring  22  will then easily slip over the leading edge  56  whereupon the locking tabs  124  snap into the depression  54  on the outer periphery of the smooth-bodied nose portion  50 . The smooth-bodied embodiment of the liquid-tight connector  184  therefore provides a connector designed specifically for engaging non-threaded apertures in a junction box. As threads are not required on the outer periphery of the nose portion  50 , the smooth-bodied embodiment of the connector  184  provides a cheaper alternative for rapidly creating a liquid-tight fit between a conduit and a panel or junction box. This embodiment however does not provide the flexibility of being able to remove the snap ring  22  and screw into a threaded access hole. 
   As seen in  FIGS. 10 and 12 , the number of individual segments  128  in the preferred embodiment of the snap ring  22  is 12. The segments  128  extend circumferentially approximately 270° with an area  138  free of segments extending over the area covered by the tongue  102  and groove  104 . 
   Thus, the invention defines a versatile threaded snap in connector that is readily utilized by electricians to connect cable and electrical tubing to electrical junction boxes with the easily applied snap in feature for connection to an electrical junction box; but, at the same time can be utilized to make the connection by lock nut or by threaded access holes. To expose the threads for the threaded connection, it is only necessary to remove the snap ring. Because of this arrangement, the electrician can minimize his variety of connectors for a job. 
   As used herein the terms relating to right angles and inclined inward are in reference to an axis through the longitudinal center of the connector. Various references herein such as bent inward and so forth are with reference to the longitudinal axis of the snap ring or the connector as the case may be. Bent inward implies that the tang or other part is bent toward the central longitudinal axis. The tangs may also be referred herein as facing forward or trailingly. A forward bent tang is oriented such that its free end is pointed toward the leading end of the connector or piece. A tang bent trailingly is oriented with the free end of the tang pointing toward the trailing end of the connector piece. 
   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.