GB2524536A

GB2524536A - An electrical conduit coupler

Info

Publication number: GB2524536A
Application number: GB1405382.1A
Authority: GB
Inventors: Alan Clothier
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-03-26
Filing date: 2014-03-26
Publication date: 2015-09-30
Also published as: GB201405382D0

Abstract

An electrical conduit coupler 390 has a first end 310 for fitting inside a first conduit and a second end 320 with a universal fitting for receiving a second standard-sized conduit. The second end may have an internal (351, Fig 2b) or external (451, Fig 3b) thread, or prongs (570, Fig 4a). The coupler may go into a tubular protrusion 610 of a junction box 600 to connect a conduit to the box without requiring a sleeve (2000, Fig 6a). The coupler may be polymeric, and may be colour-coded to show its size. It may have internal chamfers or bevels 342, 344 to prevent snagging of the electrical wire.

Description

An Electrical Conduit Coupler

Field of the Invention

This invention relates generally to an electrical coupler which is ideally suited for S connecting conduit.

The electrical conduit coupler is typically of the type found in domestic and commercial building and industrial wiring systems.

Background

Since the advent of synthetic plastics materials, such as industrial polymers, decades ago conduit components formed from polymeric components have become commonplace in electrical conduits. The advantage of this was that they contained wires and prevented eadh faults.

Consequently components for use with the conduits, such as hollow tubes, electrical boxes and adapters, also had to be fabricated from synthetic plastics so that they were is compatible.

Such components have become standardized. Methods of interconnecting the components have become ingrained in electrical installation practice. As the manufacturing industry matured it settled into providing certain standard products in specific dimension. Acceptance of the ingrained procedures for interconnecting the products led to diminishment in creativity of new components.

Hence there are now inefficiencies in the construction of electrical conduit systems in residential and commercial buildings resulting in significant unnecessary costs and installation times that require creative solutions to overcome.

Prior Art

The prior art is viewable on hundreds of websites that can be found with an internet search. Although there many websites of vendors, there is a less diverse range of different adapters! couplers particularly suited for residential and commercial building electrical conduit systems. This is due to the need for standard parts that are easily arranged into a near infinite variety of electrical conduit systems for a near infinite variety of residential and commercial building and industrial electrical systems.

Particular examples of such prior art connectors are available for example at the following websites: http://www.qvsdirect.com and http://www.diy.com.

While all the prior art adapters and couplers have their advantage for their purpose they all suffer from lack of versatility of connect-ability.

Summary of the Invention

According to one aspect of the present invention there is a coupler with an internal passageway for electrical wire for connecting first and second conduits that has a first end with a first diameter (Di) and a second end with a second diameter (D2), the first and second diameters (Di and D2) being dimensioned such that the end with the first diameter (Di) inserts into the first conduit and the end with the second diameter (D2) receives the second conduit, characterised in that the end with the second diameter (D2) has a universal fitting for connecting to a standard conduit.

Advantageously the coupler is joinable to a second conduit that has a standard dimension such as an edge of an opening with a standardized diameter or a pipe is thread with standardized dimensions so as to simplify joining the first conduit to the second conduit with an internal passage way.

Preferably the passageway is defined by an internal passageway wall having a circular cross section. Advantageously the passageway wall has an outside surface defining the first diameter (D1), and the outside surface matches a corresponding surface on the first conduit to facilitate joining the coupler to the first conduit.

The passageway wall also has an inner surface defining the second diameter (D2).

Preferably the inner surface matches a corresponding surface on the second conduit to facilitate joining the coupler to the second conduit.

Preferably the passageway wall has an internal abutment that is chamfered or beveled so as to prevent snagging of an electrical wire.

Preferably the coupler has a viewable external surface with a predetermined colour corresponding to the first diameter (Di). The colour makes it easy for a user to select a matching coupler for a matching item of electrical conduit. Preferably the coupler is included in a kit of parts comprising an electrical junction box having a hollow tubular protrusion. Preferably the hollow tubular protrusion is also marked with the same predetermined colour to indicate the coupler is joinable to the junction box as the first diameter (Di) matches the in internal diameter of the hollow tubular protrusion.

Preferably the first diameter (Di) and the second diameter (D2) are compatible with first and second conduits having standard metric diameters.

Preferably the coupler joins a hollow tubular protrusion formed integrally with a junction box to a distal electrical wire conduit by an internal passageway wall; the coupler having a first proximate end with an outer surface of the passageway wall to match an inner surface of the tubular protrusion and also having a second distal end comprising a distal coupling means to engage with a surface defining an opening into the distal electrical wire conduit.

Preferably the coupler is formed from polymeric material so as to be compatible with existing polymeric components for housing and carrying wires in residential and commercial buildings. Polymeric components do not conduct electricity since the polymeric material is electrically insulating. A system of polymeric components including the polymeric coupler prevents electrical shocks from the electrical wires is housed within the component passageways and compartments.

Advantageously the coupler joins to a hollow tubular protrusion. Hollow tubular protrusions have become commonplace features of electrical conduit boxes. The boxes provide a compartment for connecting electrical wiring and for housing fuses, switches, and other electrical circuit necessities. The coupler is therefore useful with an important component, electrical component boxes that are now used around the world in residential and commercial buildings and industrial systems.

The coupler joins a hollow tubular protrusion to a distal electrical wire conduit by an internal passageway wall. Throughout this specification the term passageway defines a passageway suitable for electrical wires to pass through. An electrical wire suitable for carrying electrical current in residential and commercial buildings may extend though the tubular protrusion and pass through the passageway of the coupler into the distal electrical wire conduit. Advantageously electrical shorts and shocks are prevented as the wire is protected by virtue of it being carried inside the passageway.

The distal electrical wire conduit may be an electrical box, a stiff or a flexible tube, or any other electrical item that houses electrical wire. Advantageously the coupler provides a passageway for electrical wire from the hollow tubular protrusion to the distal electrical wire conduit.

The coupler has a proximate end with an outer surface of the passageway wall to match an inner surface of the tubular protrusion. The coupler is couple-able to the tubular protrusion by coupling the outer surface of the passageway wall of the coupler to the inner surface of the tubular protrusion. Thus advantageously the coupler is compatible with commonplace electrical conduit boxes which comprise hollow tubular protrusions to provide access for electrical wires into the electrical box.

The coupler also has a distal end comprising a distal coupling means to engage with a surface defining an opening into the distal electrical wire conduit. The distal electrical conduit may be a long hollow tube, either stiff or flexible, carry an electrical wire to a far part of a residential or commercial building. The distal electrical conduit may be another electrical box. Advantageously the coupler is a device that enables an electrical box having a standard hollow tubular protrusion, which is a commonplace box around the world, to be easily joined with a variety of distal electrical wire conduits.

An insulated passageway for electrical wires is provided by the conduit so that the coupler is compatible with residential or commercial wiring systems.

Preferably the coupler is in the form of a hollow tube defining the passageway wall whereby the proximate end of the coupler is arranged to slip into the protrusion. It is common for hollow tubular protrusions extending from electrical conduit boxes to have a tubular passageway that provides access for electrical wires into the electrical conduit box. Advantageously by providing the coupler in the form of a hollow tube defining the passageway wall, the coupler is thereby arranged to slip easily into hollow tubular protrusion. The tolerance between the passage way outer surface of the coupler and the inside surface of the protrusion such there is a slip fit. Slipping coupler into the hollow tubular protrusion joins the coupler to the hollow tubular protrusion. Slipping the coupler into the hollow tubular protrusion also provides a continuous passageway for electrical wire through the coupler into the hollow tubular protrusion.

Preferably the passageway wall has a circular cross section. This is advantageous because it is common for hollow tubular protrusions extending from electrical boxes to have a circular passageway wall. Hence the coupler is arranged to join to common electrical boxes with electrical boxes commonly available.

Preferably the distal coupling means of the coupler is an external surface of the passageway wall shaped as an external pipe thread or is an internal surface of the passageway wall shaped as an internal pipe thread. The coupler can connect to any distal electrical wiring conduit having a matching pipe thread. This is advantageous because hollow pipe made from polymeric material is commonly available with pipe thread. Thus construction of electrical systems using polymeric material is made simpler and easier by the versatile a polymeric electrical conduit coupler.

Preferably the distal coupling means comprises prongs extending longitudinally from the passageway wall and arranged to engage with an edge of an opening in an electrical conduit box. It is common for electrical conduit boxes to comprise an edge defining an opening so as to provide a passageway for electrical wire into the electrical box. A coupler having distal coupling means comprising prongs needs only for the prongs to be inserted into the box opening to join with the box and provide a passageway for wire extending through the coupler passageway to enter the box through the box opening. Advantageously the prongs also engage with the edge of the opening so as to join the coupler to the electrical box thereby simplifying construction of a polymeric electrical conduit system for residential and commercial buildings.

is According to another aspect of the present invention a kit of parts is provided comprising a polymeric electrical conduit coupler as described herein and a polymeric electrical conduit box with a hollow tubular protrusion providing a passageway into the box. Advantageously the versatility of the electrical conduit box is multiplied over that of an electrical conduit box alone since the box and coupler together can easily be connected to a great variety of polymeric conduit components suitable for use in an electrical conduit system comprising polymeric components.

According to another aspect of the present invention a kit of parts is provided comprising a polymeric electrical conduit coupler as described herein and an electrical wire conduit in the form of a box with a surface defining an opening into the electrical wire conduit. Advantageously the versatility of the electrical conduit box is multiplied over the that of an electrical conduit box alone since the box and coupler together can easily be connected a hollow tubular protrusion which is a common device for on many electrical conduit components for providing access by an electrical wire into to its interior.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Brief Description of the Figures

Figure 1 a is a perspective view of an electrical conduit adapter known in the prior art.

Figure lb is a side view of the adapter shown in Figure lb. Figure 2a is a perspective view of a first example of an electrical conduit coupler according to the present invention.

Figure 2b is a side view of the first example of the coupler shown in Figure 2a.

Figure 3a is a perspective view of a second example of an electrical conduit coupler according to the present invention.

Figure 3b is a side view of the second example of the coupler shown in Figure 3a Figure 4a is perspective view of a third example of an electrical conduit coupler according to the present invention.

Figure 4b is a side view of the third example of the coupler shown in Figure 4a.

Figure 5a is perspective view of an electrical wire conduit junction box comprising a standardized hollow tubular protrusion.

Figure 5b is top view of an electrical wire conduit shown in Figure 5a.

Figure 6a shows an arrangement to connect an electrical conduit adapter as known in

the prior art to a hollow tubular protrusion.

Figure 6b shows an arrangement to connect a standard pipe as known in the prior art to a hollow tubular protrusion.

Figure 7a shows a system of comprising an electrical conduit box with a hollow tubular protrusion connected to a first example of the coupler according the present invention shown in Figures 2a and 2b.

Figure 7b shows a system of comprising an electrical conduit box with a hollow tubular protrusion connected to a third example of the coupler according the present invention shown in Figures 3a and 3b.

Detailed Description of Preferred Embodiments of the Invention Referring to the Figures there is shown in Figure la and Figure lb an electrical wire conduit adapter 89 according the prior art. Figure 1 a shows a perspective view of the adapter 89 and Figure lb shows a cross sectional view of it. The adapter 89 is an S intermediary device that facilitates joining two standardized items of electrical wire conduit.

The prior art adapter 89 has the form of a hollow tubular conduit having a first end 10 and a second end 20. The first end and second ends are distal ends of the conduit.

The adapter form is defined by a tubular passageway wall 40 which in turn defines a passageway 30 with an entrance into the first end 10 and an exit from the second end 20. The passageway 30 is suitable for housing electrical wire as used in residential and commercial buildings.

At the first end 10 the tubular passageway wall 40 defines a particular type of tube. In particular the tube is one of standardized inner diameter and outer diameter 80 in the is field of building wiring. The diameter dimensions at the first end are critical so that the prior art adapter 89 is fit for purpose. The purpose of the inner and outer diameter dimensions is to make the first end compatible with other electrical conduit having the same standardized dimensions so as to facilitate joining the first end 10 to another electrical conduit.

The prior art adapter 89 has standardized dimensions of its inner and outer diameter so as to join with electrical conduit boxes which have matching standardized dimensions for items of conduit for electrical wiring for commercial and residential buildings.

A perspective view of a first example of an electrical conduit coupler 390 according to the present invention is shown in Figure 2a. A cross section view of the coupler 390 is shown in Figure 2b.

The coupler 390 has the form of a hollow tubular conduit having a first end 310 and a second end 320. The first end and second ends are distal ends of the conduit. The coupler 390 form is defined by a tubular passageway wall 340 which in turn defines a passageway 330 with an entrance into the first end 310 and an exit from the second end 320. The passageway 330 is suitable for housing electrical wire as used in residential and commercial buildings.

At the first end 310 of the coupler 390 the tubular passageway wall 40 defines a special tube unique to the invention for this type of coupler for use with electrical conduit. At the first end 310 the special tube is one of non-standard outer diameter 351 in the field of building wiring. The outer diameter dimension D1 351 of the first end is critical so that the coupler 390 is fit for purpose. The purpose of the special outer diameter dimension D of the first end is to facilitate the first end 310 of the coupler to slip into an item of electrical conduit having an opening with a standardized dimension in the field of building wiring. Thereby the coupler 390 is join-able by its first end 310 to another item of electrical conduit having an opening with a standardized dimension.

The second end 320 of the coupler 390 is in the form of an internally threaded pipe.

The pipe threads 351 are formed to standardized dimensions for pipe threads. The diameter of the threads is shown as D2 353 at the entrance the passageway 330 defined by the internal surface of the passageway wall. The second end 320 of the prior art adapter 390 is thereby dimensioned to join to another item of electrical wire conduit having a matching external thread of standardized dimensions.

Figures 3a and 3b show a second example of the coupler 490 according to the invention. The second example of the coupler 490 is like the first example of the coupler 390, except that at the second end 420 of the third example of the coupler 490 there are standardized external pipe threads 451 with a standard diameter D2 453.

Thus the first end 410 of the coupler 490 has a special diameter Dl 481 that is nonstandard so that the passageway wall 440 at the first end 410 is able to slip inside a standard inner diameter of an electrical conduit that is standard in the electrical wiring of buildings. The length 450 of the second end is at least a third of the length of the non standard diameter Dl.

A perspective view of a third example of an electrical conduit coupler 590 according to the present invention is shown in Figure 4a. A cross section view of the third example of the coupler 590 is shown in Figure 4b.

The coupler 590 has the form of a hollow tubular conduit having a first end 510 and a second end 520. The first end and second ends are distal ends of the conduit.

Like the first example of the coupler 390 and the second example 490, the third example of the coupler 590 form is defined by a tubular passageway wall 540 which in turn defines a passageway 530 with an entrance into the first end 510 and an exit from the second end 520. The passageway 530 is suitable for housing electrical wire as used in residential and commercial buildings.

The first end 510 of the third example of the coupler 590 is the same as the first end 310 of the first example of the coupler 390 and also as the first end 410 of the second example of the coupler 490.

At the first end 510 of the coupler 590 the tubular passageway wall 40 defines a special tube unique to the invention for this type of coupler for use with electrical conduit. The first end of 510 of the tube has a non-standard outer diameter 581 in the field of building wiring. The outer diameter dimension D1 581 of the first end is critical so that the coupler 590 is fit for purpose. The purpose of the special outer diameter dimension D1 of the first end is to facilitate the first end 510 of the coupler 590 to slip into an item of electrical conduit having an opening with a standardized dimension in the field of building wiring. Thereby the coupler 590 is join-able by its first end 510 to another item of electrical conduit having an opening with a standardized dimension.

The second end 520 of the coupler 590 has in a form comprising prongs 570 to engage with the edge of an opening of a standardized dimension in the field of electrical building wiring. The diameter between the prongs is shown as D2 553 at the entrance the passageway 530 defined by the internal surface of the passageway wall. The diameter between the prongs is a standardized diameter for the edge of an aperture in an item of conduit in the field of electrical building wiring. The coupler 590 is tubular as defined by passageway wall 540 which has a tubular axis, and the prongs extend away from the passageway wall 540 in the direction of tubular axis. The prongs comprise barbs to grasp the edge of the opening in the item of electrical conduit.

Figure 5a shows a perspective view of an electrical conduit junction box 600. Figure Sb shows a top view through the junction box 600 cross section.

As shown in Figures 5a and Sb, the junction box 600 has hollow tubular protrusions 610 that protrude from the box wall 670. Each hollow tubular protrusion 610 defines a passageway into the junction box 600.

The hollow tubular protrusion has an inner diameter and an outer diameter 680. The dimensions of the hollow tubular protrusion are standardized dimensions that are standard for electrical wire conduit in the field of electrical building wiring.

The adapter 89 known in the prior art and illustrated in Figures la and lb also has standardized dimensions for the inner diameter and outer diameter 80 of the first end 10. Thus the first end 10 of the known adapter 89 is not joinable to the hollow tubular protrusion 610 of the junction box 600. This is illustrated in Figure 6a.

In order to connect an item of conduit having the dimensions of a standard tube to hollow tubular protrusion also having the dimensions of a standard tube, a cylindrical S sleeve 2000 is required as shown in Figure 6a.

Figure 6b shows a similar example of a standard tube 190 connected at its first end to the hollow tubular protrusion 610 of a junction box 600 using cylindrical sleeve 2000.

The standard tube has a standard inner diameter and a standard outer diameter 180 common to standard electrical conduit used for electrical wiring of buildings.

To facilitate connection of junction boxes having hollow tubular protrusions having standard dimensions to other electrical conduit items it is accepted practice ingrained in the electrical wiring industry to use a the sleeve 2000 connecting tubes 610, 10, 110 by the arrangement illustrated by Figures 6a and 6b.

The coupler 390, 490, 590 of the present invention saves the use of a sleeve when is joining another item of conduit for electrical wiring to a hollow tubular protrusion 610 having standardized dimensions. It also makes it possible to join another item of conduit for to an electrical junction box 600 since the coupler 390, 490, 590 is directly joinable to it.

Figure 7a illustrates the first example the coupler 390 joined to a hollow tubular protrusion 610 of a junction box 600. The non-standard outer diameter D1 381 of the first end 310 of the coupler 390 slips inside the standard inner diameter 680 of the hollow tubular protrusion 610.

The passageway wall 340 has an entranceway chamfer 344 at the first end 310 entrance 344 to the passageway 330. The chamfer aids threading an electrical wire (not shown) through the passageway as the tip of wire easily slides past the chamfer 344. The passageway wall 340 also has an intermediate chamfer 342 where first end 310 meets the second end 320. The intermediate chamfer 342 serves the same purpose of facilitating threading of the wire. Thus all internal abutments in the passageway are chamfered or beveled so as to prevent snagging of electrical wire.

To ensure a robust joint between the first end 310 of the coupler 390 and the hollow tubular protrusion 610 of the junction box 600, the length 350 of the first end 310 is at least one third of the outer diameter 381 of the first end. This is enough length that a sufficient length of overlap between the coupler 390 and protrusion 610 is obtainable.

S An adhesive is paintable on the outer surface of the first end 310 of the coupler 390.

Inserting the first end 310 into the hollow tubular protrusion 610 glues the protrusion 610 to the coupler 390.

Figure 7b shows the third example of the coupler 590 shown in Figure 4a and 4b joined to a hollow tubular protrusion 610. The non-standard outer diameter D1 581 of the first end 510 of the coupler 590 slips inside the standard inner diameter 680 of the hollow tubular protrusion 610.

The coupler 390, 490, 590 joins to the hollow tubular protrusion by virtue of the first end 310, 410, 510 having an outer surface 311, 411, 511 of the passageway wall 340 to match an inner surface 611 of the tubular protrusion 610. The coupler 390, 490, 590 also has a second end 320, 420, 520 comprising a distal coupling means to engage with a surface defining an opening into a second electrical wire conduit item such as for example a standard threaded pipe or an electrical conduit box 200.

The junction box 600 having a hollow tubular protrusion with standardized dimensions and the coupler 390, 490, 590 are supply-able together as a kit of parts. A user of the kit of parts finds the junction box more versatile. Together the coupler 390, 490, 590 and the junction box 600 are joinable by the second end 320, 420, 520 of the coupler directly to an item of conduit having the standard dimensions of electrical conduit used in residential and commercial buildings.

The invention has been described by way of examples only. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the claims.

Claims

Claims: 1. An electrical conduit coupler with an internal passageway for electrical wire for connecting first and second conduits has a first end with a first diameter (Di) and a second end with a second diameter (D2), the first and second diameters (Di and 02) S being dimensioned such that the end with the first diameter (Di) inserts into the first conduit and the end with the second diameter (D2) receives the second conduit, characterised in that the end with the second diameter (D2) has a universal fitting for connecting to a standard conduit.
2. A coupler according to claim 1 wherein the passageway is defined by an internal passageway wall having a circular cross section and an internal abutment of the passageway way is chamfered or beveled so as to prevent snagging of an electrical wire.
3. A coupler according to claim 1 or 2 wherein the second end has an external surface of the passageway wall shaped as external pipe thread.
4. A coupler according to claim 1 or 2 wherein the second end has an internal surface of the passageway wall shaped as internal pipe thread.
5. A coupler according to claim 1 or 2 wherein the second end comprises prongs extending longitudinally from the passageway wall and arranged to engage with an edge of an opening in an electrical conduit box.
6. A coupler according to any preceding claim having a viewable external surface with a predetermined colour corresponding to the first diameter (D1).
7. A coupler according to any preceding claim where the first diameter (Di) and the second diameter (D2) are compatible with first and second conduits having standard metric diameters.
8. A coupler according to any preceding claim is formed from an electrically insulating material.
9. A coupler according to any preceding claim joins a hollow tubular protrusion formed integrally with a junction box to a distal electrical wire conduit by an internal passageway wall; the coupler having a first end with an outer surface of the S passageway wall to match an inner surface of the tubular protrusion and also having a second end comprising a coupling means to engage with a surface defining an opening into the distal electrical wire conduit.
10. A kit of parts comprising a coupler according to any preceding claim and a polymeric electrical conduit box with a hollow tubular protrusion providing a passageway into the box.
11. A kit of parts comprising a coupler according to any of claims 1 to 6 and an electrical wire conduit in the form of a box with a surface defining an opening into the electrical wire conduit.
12. A kit of pads according to claims 10 or 11 includes an adhesive to bond the outer surface of the passageway wall to the inner surface of the hollow tubular protrusion.
13. A kit of parts according to claims 10, 11 or 12 wherein the coupler and box are colour or otherwise marked to indicate the coupler is joinable directly to the protrusion.
14. A coupler substantially as described herein with reference to the accompanying drawings.