Patent Publication Number: US-2020287366-A1

Title: Conduit coupling assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to assembly of conduits, tubing, and like components in a building or other structure, and more particularly to a conduit coupling assembly which facilitates joining liquid-tight connectors to a conduit positioned in a concrete slab or similar environment. The present coupling assembly facilitates attachment of polyvinyl chloride (PVC) conduit material to an associated, composite liquid-tight conduit having a metallic core and a polymeric protective coating. 
     BACKGROUND OF THE INVENTION 
     Electrical conduit and related accessories may be made from a variety of materials such as PVC, thin wall metal, heavy wall metal, flexible tubing (MC cable and other types of flexible cable), as well as other materials known to those skilled in the art. For some applications, composite conduit assemblies, such as comprising a metallic core and a polymeric protective coating, are required. Often-times, these materials are used in combination and therefore, adapters and couplings must be used to join the materials. Couplings are generally used to connect tubing, such as electrical conduit to various other forms of electrical tubing and support structures. In some applications, electrical conduit can be arranged to extend at least partially within a floor structure, such as a concrete slab. 
     In the course of a typical installation, it may be necessary for electrical workers to provide conduit components which extend from within a concrete slab or like floor element for connection with other components positioned about the concrete slab. Bearing in mind that electrical wiring positioned within the conduit components must be threaded and directed through the various components, it is desirable to provide an arrangement which facilitates assembly of the components, while promoting efficient routing of the associated wiring. 
     The present invention is directed to conduit coupling assembly which facilitates assembly of liquid-tight connectors, and associated tubular structures, with conduit components typically used in conjunction with electrical wiring, with the present invention particularly suited for applications in which conduit components are positioned in a concrete slab or like flooring structure. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a conduit coupling assembly and method of installation which particularly facilitates efficient connection of liquid-tight connectors and associated tubing to conduit components, typically polyvinyl chloride, positioned in a concrete slab or like structure. The assembly can be used in wet environments, such as in the area of cooling towers in data centers. The arrangement eliminates rigid nipples, by directly connecting PVC conduit to a liquid-tight flex conduit on equipment, generators, transformer gear, switch gear, ATS switches, and the like. Connection from concrete pads to various heating, ventilation and air conditioning equipment is facilitated. 
     In accordance with the present invention, the present method of forming a coupling assembly comprises the steps of providing a conduit, typically formed from polyvinyl chloride (PVC) in an associated building slab, or like structure, so that the conduit projects from the surface of the slab. The method includes cutting a portion of the conduit which projects above the surface of the slab to prepare the conduit for connection. 
     The present method further contemplates cutting the conduit at an inside surface thereof to form a connection region, which is preferably tapered. This step is preferably effected by reaming the interior surface of the conduit to provide an inner surface for assembling the components of the assembly. 
     Next, a transition coupling is provided, with the transition coupling inserted into the conduit in the tapered, connection region of the conduit. Industrial grade adhesive is provided to securely and permanently adhere the transition coupling to the conduit. 
     The present method next includes providing cooperating, liquid-tight male and female connectors. These types of connectors are ordinarily used in applications where resistance to the ingress of water, moisture, or other liquid or fluids is mandated. As noted, such applications can include cooling towers, transformers, switch gear, and like environments and applications where waterproof connections are required. 
     The assembly is completed by joining one of liquid-tight connectors to transition coupling, to thereby facilitate joining the other of liquid-tight connectors to the conduit in the associated slab. To this end, the transition coupling is preferably provided with a male thread formation on an exterior surface therefore for threaded engagement with a female thread formation provided at an interior surface of the connector joined to the transition coupling. Adhesive applied to the thread formations secures them to each other. The light-tight connectors can be threaded or unthreaded as may be required for joining associated tubing or the like to the conduit positioned in the associated slab. 
     Other features and advantages will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic, perspective view of the present conduit coupling assembly, which can be joined to a conduit in an associated concrete slab, as typical in a structure for which the present invention is suited for use; 
         FIG. 2  is an exploded, diagrammatic view further illustrating components of the present conduit coupling assembly; and 
         FIG. 3  illustrates the steps performed in accordance with the present invention for joining a liquid-tight connector to the conduit. 
     
    
    
     DETAILED DESCRIPTION 
     While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment, with the understanding that the present disclosure is intended as exemplification of the invention, and is not intended to limit the invention to the specific embodiment 
     This invention pertains to couplings and adapters for conduits and tubular members, and in more particularly to an arrangement including a conduit coupling assembly configured to facilitate connection of liquid-tight tubing to an associated conduit section, wherein the conduit section is disposed in an associated floor or concrete slab. Associated electrical wiring or the like can be arranged to extend from within the conduit in the concrete slab, and through the coupling assembly and the associated liquid-tight tubing. 
     With reference to the illustrated embodiment, the present invention is directed to a conduit coupling assembly, designated  10 , and a method of installation which particularly facilitates efficient connection of liquid-tight connectors and associated tubing to conduit components, typically polyvinyl chloride (PVC), positioned in a concrete slab C or like structure. The assembly  10  can be used in wet environments, such as in the area of cooling towers in date centers. The arrangement eliminates rigid nipples, by directly connecting PVC conduit to a liquid-tight flex conduit on equipment, generators, transformer gear, switch gear, ATS switches, and the like. Connection from concrete pads to various heating, ventilation and air conditioning equipment is facilitated. 
     In accordance with the present invention, and as diagrammatically illustrated in  FIG. 3 , the present method of forming a coupling assembly comprises the steps of providing a conduit  12 , typically formed from polyvinyl chloride (PVC) in the associated building slab C or like structure so that the conduit projects  12  from the surface of the slab. This is illustrated in Step  1  of  FIG. 3 . 
     As illustrated in Step  2  of  FIG. 3 , the present method includes cutting a portion of the conduit  12  which projects above the surface of the slab C to prepare the conduit for connection. 
     With reference now to Step  3  as illustrated in  FIG. 3 , the present method next contemplates cutting the conduit  12  at an inside surface thereof to form a connection region  14 , which is preferably tapered inwardly in a direction away from the conduit opening, ie, downwardly and innwardly in the illustrated embodiment. This step is preferably effected by reaming the interior surface of the conduit  12  to provide an inner surface at  14  for assembling the components of the present assembly. 
     Next, a transition coupling  16 , configured in accordance with the present invention, is provided, with the transition coupling  16  inserted into the conduit  12  in the tapered, connection region  14  of the conduit. The transition coupling  16  is preferably formed for PVC for economical and durable service. The exterior of the transition coupling is provided with a tapered surface which is complementary to the tapered, connection region  14  of the conduit  12 . Industrial grade adhesive is provided to securely and permanently adhere the transition coupling to the conduit. Step  4  illustrated in  FIG. 3  shows this step of the process, with the conduit coupling assembly  10  illustrated joined to the conduit  12 . As illustrated, the inside diameter of the transition coupling  16 , as shown in phantom line at  18 , is the same as the inside diameter of conduit  12  to facilitate the smooth passage of wiring through the assembled components. 
     As shown, the present method includes providing cooperating, liquid-tight male and female connectors,  20 ,  22 . These types of connectors are ordinarily used in applications where resistance to the ingress of water, moisture, or other liquid or fluids is mandated. As noted, such applications can include cooling towers, transformers, switch gear, and like environments and applications where waterproof connections are required. A ferrell  23  is positioned and held in captive relationship between the connectors  20 ,  22 . This ferrell is joined to associated liquid-tight tubing attendant to assembly of the components. 
     The present coupling assembly is completed by joining one of liquid-tight connectors  20 ,  22 , to the transition coupling  16 , to thereby facilitate joining the other of liquid-tight connectors to the conduit in the associated slab. In the illustrated embodiment, the male liquid-tight connector  20  is joined to the transition coupling  15 . To this end, the transition coupling  16  is preferably provided with a male thread formation  17  on an exterior surface thereof ( FIG. 2 ) for threaded engagement with an internal, female thread formation, shown in phantom line at  21 , provided at an interior surface of the connector  20  joined to the transition coupling  16 . Adhesive applied to the thread formations  17 ,  21  secures them to each other. The light-tight connectors  20 ,  22  can be threaded or unthreaded as may be required for joining associated tubing or the like to the conduit positioned in the associated slab. 
     As will be appreciated from the above description, the exact order in which components of the present assembly are joined to each other and assembled can be varied in accordance with the requirements of any specific application. 
     From the foregoing, it will be observed that numerous modifications and variations of the present invention can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.