AU2014202837B1

AU2014202837B1 - A cable terminator

Info

Publication number: AU2014202837B1
Application number: AU2014202837A
Authority: AU
Inventors: Jason Twyman
Original assignee: Individual
Current assignee: Twyman Jason
Priority date: 2014-02-13
Filing date: 2014-05-23
Publication date: 2014-09-18
Anticipated expiration: 2034-05-23

Abstract

The present invention relates to a cable terminator and a method for terminating a cable for a switch of a switchboard.

Description

1 A CABLE TERMINATOR TECHNICAL FIELD [0001] The present invention generally relates to a cable terminator for terminating a cable for a switch of a switchboard. BACKGROUND [0002] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. [0003] Switchboards, also known as distribution boards, circuit breaker panels, electrical panels, meter boxes or fuse boxes, are a component of electrical supply systems which divide an electrical power feed into subsidiary circuits, while providing a protective switch such as a fuse or circuit breaker for each circuit. [0004] A typical switchboard may contain anywhere from two to upwards of a hundred switches depending on the size of the building in which the switchboard is located. Generally, each switch is labelled to facilitate easy location of which switch to shut off for servicing, rewiring or the like. [0005] Nevertheless, the shutting off of a particular switch is not a fail-safe method of isolating a specific hard-wired electrical component requiring repair, such as, for example, a hot water system. Particularly, since the switch can be readily switched back on by an unaware third party, which could potentially be fatal to the technician undertaking the repair work. Consequently, technicians may additionally isolate a particular circuit by physically disconnecting a cable or circuit tail from the switch. [0006] A problem associated with such practices is that once the work on the isolated electrical component has been completed, the disconnected cable needs to be re-connected to the correct switch. While this may not be a problem in a small residential dwelling with a limited number of switches, it becomes a problem in commercial buildings, which may contain numerous switches, including more than one unconnected or unused switch. Additionally, commercial buildings may contain numerous cable ends of the same colour and size that may not be connected to any switches (i.e., dead ends).

2 [0007] To avoid such problems, technicians, typically, mark or label disconnected cables by, for example, writing on the cable or, more commonly, on a piece of tape tied or tethered around the cable end, the particular switch from which the cable was disconnected. The use of tape is more common because in many jurisdictions it is mandatory that disconnected cable ends be capped or isolated. [0008] Nevertheless, such markings on cable or on tape can be unclear, partially rubbed-off or simply misread, and tape around a cable end may come untied and fall off. Both of these outcomes are undesirable and increase the risk of a circuit, for instance, being overloaded through the mismatched re-connection of cable to switch. [0009] Embodiments of the present invention provide a fail safe way of isolating a cable end from a switch while mitigating the risk of the cable end being re-connected to the wrong switch or, conversely, the wrong cable end being connected to the switch. SUMMARY OF INVENTION [0010] According to a first aspect of the present invention, there is provided a cable terminator for terminating a cable for a switch of a switchboard, the terminator including: an insulator for insulating an end of the cable; and connection means to facilitate connection of the insulator to the switch, said connection means including a male portion in the form of a projection standing proud from the insulator configured to be engageable with a female portion located on the switch. [0011] Advantageously, the terminator terminates a cable end with an insulator thereby fulfilling the mandatory requirement in many jurisdictions to cap or isolate a disconnected cable end. Furthermore, the terminator eliminates the need to mark or label a disconnected cable by allowing the insulated cable end to be re-connected to the switch in a fail-safe manner via the connection means. As such, the terminator also mitigates the risk of a disconnected cable being re-connected to the wrong switch or, conversely, the wrong cable being connected to the switch. [0012] The insulator may be of any size, shape and construction and may be formed of any material or materials suitably adapted to insulate the end of the cable and prevent the cable from being directly connected to the switch. [0013] Typically, the insulator may be configured to substantially encompass a stripped 3 end of the cable. In this regard, the insulator may have a body defining a cavity suitably sized and shaped for receiving the end of the cable. Furthermore, the cavity may be sized and shaped to receive more than one cable end. [0014] In a preferred embodiment, the cavity may be tapered having a wider mouth than inner end. In particular, the cavity may have a mouth that tapers or narrows to a cylindrical cavity portion located at or near the inner end. Advantageously, the wider mouth may facilitate the connection of the insulator to the end of the cable by guiding the cable end toward the inner end where it may frictionally fit within the cylindrical cavity portion. The wider mouth may also facilitate in the connection of the insulator to more than one cable end. [0015] Preferably, the cavity may have a longitudinal length sufficient to accommodate the stripped end of the cable. [0016] The insulator will be formed from a non-conductive material such as glass, porcelain, rubber or plastic. Preferably, the insulator may be formed from a transparent or translucent plastic so that, in use, a technician may visually check that the insulator has been correctly fitted to the end of the cable. The insulator may also have a distinct colouring, such as, for example, orange colouring so that a technician can readily identify the terminator of the present invention. [0017] The connection means for facilitating connection of the insulator to the switch may be of any suitable size, shape and construction. For example, the connection means may be in the form of a fastener such as a clamp, a tie or an adhesive configured to fasten the insulator to the switch. Alternatively, the connection means may include a portion engageable with another portion of the switch (i.e., a male portion engageable with a female portion). [0018] Preferably, the connection means may include a male portion associated with the insulator and engageable with a female portion located on the switch. The male portion may be in the form of a projection formed from a non-conductive material standing proud from the insulator. The projection may be suitably sized, positioned and shaped to be received within the female portion. That is, the projection may a have cross-sectional shape that is received in and complements the cross-sectional shape of the female portion. [0019] The male portion may be a separate component piece attached to the insulator, or may be integrally formed with the insulator. Preferably, the male portion may be integrally 4 formed with the insulator. More preferably, the projection may orthogonally extend from the body of the insulator relative to the longitudinal length of the cavity. [0020] The female portion will be in the form of a terminal connector of the switch. Typically, the female portion will be the terminal connector from which the cable end was initially disconnected. [0021] Once received within the terminal connector, the male portion may be secured in place by tightening a terminal screw of the terminal connector (i.e., the female portion). Preferably, however, the male portion may be sized and shaped to frictionally fit in the terminal connector. [0022] The terminator may further include fastening means for fastening the insulator to the end of the cable. The fastening means may be integrally formed with the insulator or, preferably, may be a separate component piece in the form of a clip, a threaded fastener, an adhesive or a clamp, preferably a threaded fastener. Advantageously, the inclusion of fastening means to fasten the insulator to the end of the cable reduces the risk of the insulator inadvertently being detached from the cable end. [0023] In a preferred embodiment, the threaded fastener may be orthogonally positioned relative to the longitudinal length of the cavity such that, in use, the fastener may fasten the cable end against an inside wall of the cylindrical cavity portion of the cavity. More preferably, the threaded fastener may be located on an opposite side of the body of the insulator relative to the male portion of the connection means. [0024] The head of the threaded fastener may be recessed within the body of the insulator to prevent or minimise unintended contact with the fastener. Alternatively and preferably, the head of the threaded fastener is recessed within a cylindrical sleeve extending outwardly from the body of the insulator to, again, prevent or minimise unintended contact with the fastener. [0025] The cavity of the insulator may further include a conductive band sized and shaped to receive one or more cable ends received within the cavity and to threadingly engage with the threaded fastener such that, in use, the fastener may fasten the one or more cable ends against an inner surface of the band. Preferably, the conductive band may be fitted within the cylindrical cavity portion of the cavity. The conductive band advantageously facilitates in the terminator of the present invention being alternatively used as a cable connector.

5 [0026] The terminator may further include waterproofing means to, in use, prevent water from entering into the insulator. The waterproofing means may be of any suitable size, shape and construction to prevent water from entering into the insulator. For example, the waterproofing means may include any one of a sealing member such as a plug; a sealing agent; or an enclosure. [0027] The waterproofing means may include distinct sealing member pieces or may be of a unitary or one-piece construction. Preferably, the waterproofing means may be of a one-piece construction, wherein at least two sealing members may be linked together by a linker. [0028] Preferably, the at least two sealing members may be configured to respectively seal the mouth of the cavity and an opening of the cylindrical sleeve extending outwardly from the body of the insulator within which the head of the threaded fastener is recessed. The at least two sealing members may be formed from any suitable waterproofing material or materials such as, for example, rubber, polyvinyl chloride (PVC), polyurethane (PU), silicone elastomer, fluoropolymers, or wax. [0029] Each sealing member may include a resilient plug portion having an outwardly extending lip configured to lock or hook over a corresponding inner rim defined at the mouth of the cavity and the opening of the cylindrical sleeve. To ensure a watertight seal is formed, a sealing agent may also be applied to any one of the outwardly extending lips of the plug portions and the corresponding inner rims of the mouth of the cavity and the opening of the cylindrical sleeve. [0030] The sealing member for the mouth of the cavity may further include at least one pierceable portion configured to be pierced by a cable end to facilitate insertion of the cable end into the insulator while maintaining a substantially water-tight seal. It is envisaged that the at least one pierceable portion of the sealing member for the mouth may be about half as thick as the remainder of the sealing member to facilitate ease of piercing by the cable end. [0031] According to a second aspect of the present invention, there is provided a method of terminating a cable for a switch of a switchboard using the cable terminator of the first aspect, the method including: insulating an end of the cable with the insulator; and connecting the insulator to the switch with the connection means.

6 [0032] The method may include one or more features or characteristics of the terminator as described hereinbefore. [0033] For example, the method may further include the step of fastening the insulator to the end of the cable with fastening means. [0034] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. BRIEF DESCRIPTION OF DRAWINGS [0035] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of Invention in any way. The Detailed Description will make reference to a number of drawings as follows: [0036] Figure 1A is a rear view of a terminator according to an embodiment of the present invention; [0037] Figure 1B is a front view of the terminator as shown in Figure 1A; [0038] Figure 1C is a side view of the terminator as shown in Figures 1A and 1B; [0039] Figure 2A is a front view showing fastening means of the terminator as shown in Figures 1A to 1C; [0040] Figure 2B is a side view of the fastening means shown in Figure 2A; [0041] Figure 3A is a cross sectional illustration of a terminator according to an embodiment of the present invention with attached waterproofing means, said waterproofing means including two sealing members joined by a linker; [0042] Figure 3B is a cross sectional illustration of the terminator shown in Figure 3 without the attached waterproofing means; [0043] Figure 4A is an illustration of waterproofing means according to an embodiment of the present invention; and 7 [0044] Figure 4B is an enlarged illustration of a first sealing member of the waterproofing means shown in Figure 4A. DETAILED DESCRIPTION [0045] Figures 1A to 1C show a terminator (10) according to an embodiment of the present invention for terminating a cable for a circuit breaker (i.e., a switch) of a switchboard. The terminator (10) includes an insulator (20) for insulating an end of the cable and a connecting member (30; i.e., connection means) to facilitate connection of the insulator (20) to the circuit breaker. The terminator (10) also includes fastening means in the form of a bolt (40; i.e., a threaded fastener), which threadingly engages with an eye nut (50; i.e., a conductive band) located within the insulator (20) to fasten the cable end within the insulator (20). [0046] Advantageously, the terminator (10) meets the mandatory requirement in many jurisdictions to cap or isolate a disconnected cable by terminating the cable with the insulator (20). Also, the terminator (10) eliminates the need to mark or label a disconnected cable by allowing the insulated cable ends to be re-connected to the circuit breaker in a fail-safe manner via the connecting member (30). As such, the terminator (10) mitigates the risk of a disconnected cable being re-connected to the wrong circuit breaker or, conversely, the wrong cable being connected to the circuit breaker. [0047] Referring to Figures 1A to 1C, the insulator (20) has a body (21) defining a cavity (22) for receiving a cable end. The cavity (22) has a longitudinal length sufficient to encompass the stripped end of a standard 6mm electrical cable. [0048] The insulator (20) is formed from a transparent plastic that, in use, allows a technician to visually check that the insulator (20) has been correctly fitted to a cable end. [0049] Best shown in Figure 1B, the cavity (22) of the insulator (20) is tapered having a wider mouth (23) than inner end (24). The mouth (23) tapers to a cylindrical cavity portion (25) located at the inner end (24). In use, the wider mouth (23) facilitates the connection of the insulator (20) to a cable end by guiding the cable end toward the inner end (24) where the cable end can be secured in place by the bolt (40) and eye nut (50). [0050] As shown in Figures 1A to 1C, the connecting member (30) extends outwardly from the body (21) of the insulator (20) at right angles relative to the longitudinal length of the cavity (22). The connecting member (30) has a circular profile shape configured to be received in or 8 fitted to a terminal connector of the circuit breaker from which the cable was initially disconnected. In this regard, the connecting member (30) has a diameter that is about the same as the diameter of the cable end, i.e., 6mm. [0051] In use, the connecting member (30) is inserted into the terminal connector of the circuit breaker and secured in place by tightening the terminal screw of the terminal connector. [0052] Referring again to Figure 1B, the bolt (40), like the connecting member (30), is also positioned at right angles relative to the longitudinal length of the cavity (22), but on the opposite side of the body (21) relative to the connecting member (30). [0053] The bolt (40) is received through a hole (26) defined in the body (21) of the insulator (20) to threadingly engage with the eye nut (50; i.e., conductive band) located within the cylindrical cavity portion (25) of the cavity (22) of the insulator (20). [0054] In use, a cable end received in the cavity (22) is fastened by the shank end (42) of the bolt (40) against an inner surface (52) of the eye nut (50). [0055] The bolt (40) and the eye nut (50) are formed from copper. As such, the head (44) of the bolt (40) is recessed within a cylindrical sleeve (27) extending outwardly from the body (21) of the insulator (20) to prevent or minimise unintended contact with the bolt (40). [0056] Referring to Figures 2A and 2B, the eye or hole (54) of the eye nut (50) is sized and shaped to accommodate more than one cable end. Advantageously, this facilitates in the alternate use of the terminator (10) as cable connector. [0057] Referring to Figures 3A and 3B, Figure 3A illustrates another embodiment of the terminator (10) further including attachable waterproofing means in the form of a cavity sealing member (60) and a bolt sealing member (70) joined together by a linker (80). [0058] The sealing members (60, 70) and lanyard or linker (80) are formed from rubber and are of a one-piece construction. [0059] Best shown in Figure 3A, each sealing member (60, 70) includes a plug (62, 72) having outwardly extending lips (64, 74) configured to lock or hook over corresponding inwardly extending rims (23a, 28a) defined at the mouth (23) of the cavity (22) and an opening (28) of the cylindrical sleeve (27).

9 [0060] Referring to Figures 4A and 4B, the cavity plug (62) further includes four pierceable portions (66) each configured to be pierced by a cable end to facilitate insertion of a cable end into the insulator (20) while maintaining a substantially water-tight seal. Each pierceable portion (66) is about half as thick as the remainder of the cavity plug (62). [0061] A method of using the terminator (10) is now briefly described. [0062] A technician needing to carry out repair or maintenance work on a specific hard wired electrical component in a building first isolates the relevant circuit for the hard-wired electrical component by identifying and shutting-off the relevant circuit breaker in the building's switchboard. [0063] The technician then physically disconnects a cable from the relevant circuit breaker and insulates the disconnected cable end with the insulator (20) of the terminator (10). The end of the cable is inserted into the cavity (22) of the insulator (20) and secured in place. [0064] The cable end is secured in place by tightening the bolt (40) of the terminator (10), which threadingly engages with the eye nut (50) located within the insulator (20). Tightening of the bolt (40) results in the cable end being fastened against the inner surface (52) of the eye nut (50) by the shank end (42) of the bolt (40). [0065] Once the insulator (20) is securely fastened to the cable end, the insulator (20) is connected to the circuit breaker by inserting the connecting member (30), which extends outwardly from the insulator (20), into the terminal connector of the circuit breaker from which the cable was initially disconnected. The connecting member (30) is secured in place by tightening the terminal screw of the terminal connector. [0066] Once the repair or maintenance work has been completed, the terminator (10) is disconnected from the circuit breaker by loosening the terminal screw and pulling the connecting member (30) out of the terminal connector. [0067] Then, prior to re-connecting the cable to the circuit breaker and turning on the circuit breaker, the insulator (20) is removed from the cable end by loosening the bolt (40) and pulling the insulator (20) off the cable end. [0068] A person skilled in the art will appreciate that many embodiments and variations can be made without departing from the ambit of the present invention.

10 [0069] For example, in an alternative embodiment, the connecting member may be detachable and interchangeable with alternative connecting members of differing cross sectional shapes and/or sizes to facilitate connection of the insulator to different types of circuit breakers or switches. [0070] In another alternative embodiment, the connecting member may have an enlarged head to further secure the connecting member in place when fitted to a circuit breaker or switch. [0071] In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise' include each of the stated integers but does not exclude the inclusion of one or more further integers. [0072] Reference throughout this specification to 'one embodiment' or 'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases 'in one embodiment' or 'in an embodiment' in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. [0073] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

1. A cable terminator for terminating a cable for a switch of a switchboard, the terminator including: an insulator for insulating an end of the cable; and connection means to facilitate connection of the insulator to the switch, said connection means including a male portion in the form of a projection standing proud from the insulator configured to be engageable with a female portion located on the switch.

2. The terminator of claim 1, wherein the insulator has a body defining a cavity for receiving at least one cable end.

3. The terminator of claim 2, wherein the cavity includes a mouth that tapers to a cylindrical cavity portion located at or near an inner end of the cavity.

4. The terminator of claim 2 or claim 3, wherein the cavity has a longitudinal length sufficient to accommodate a stripped cable end.

5. The terminator of any one of claims 1 to 4, wherein the projection is formed from a non conductive material.

6. The terminator of claim 5 when appended to claim 4, wherein the projection extends orthogonally from the body of the insulator relative to the longitudinal length of the cavity.

7. The terminator of any one of claims 1 to 6, wherein the female portion is a terminal connector of the switch and the male portion, once inserted into the female portion, is secured in place by tightening a terminal screw of the terminal connector.

8. The terminator of any one of claims 1 to 6, wherein the female portion is a terminal connector of the switch and the male portion is sized and shaped to frictionally fit in the terminal connector.

9. The terminator of any one of claims 1 to 8, further including fastening means for fastening the insulator to the end of the cable.

10. The terminator of claim 9 when appended to claim 4, wherein the fastening means includes a threaded fastener orthogonally positioned relative to the longitudinal length of the cavity such that, in use, the threaded fastener fastens the end of the cable against an inside wall 12 of the cylindrical cavity portion of the cavity.

11. The terminator of claim 10, wherein the head of the threaded fastener is recessed within a cylindrical sleeve extending outwardly from the body of the insulator to prevent or minimize unintended contact with the threaded fastener.

12. The terminator of any one of claims 2 to 11, wherein the insulator further includes a conductive band sized and shaped to receive said at least one cable end received within the cavity.

13. The terminator of claim 12 when appended to claim 10 or claim 11, wherein the conductive band threadingly engages with the threaded fastener such that, in use, the threaded fastener fastens the at least one cable end against an inner surface of the conductive band.

14. The terminator of any one of claims 1 to 13, further including waterproofing means for preventing water from entering into the insulator.

15. The terminator of claim 14 when appended to claim 11, wherein the waterproofing means includes two sealing members linked together by a linker, each sealing member including a resilient plug having an outwardly extending lip configured to lock or hook over a corresponding inner rim defined at the mouth of the cavity and an opening of the cylindrical sleeve.

16. The terminator of claim 15, wherein the sealing member for the mouth of the cavity of the insulator includes at least one pierceable portion configured to be pierced by a cable end to facilitate insertion of the cable end into the insulator while maintaining a substantially water tight seal.

17. A method of terminating a cable for a switch of a switchboard using the cable terminator of any one of claims 1 to 16, the method including: insulating an end of the cable with the insulator; and connecting the insulator to the switch with the connection means.

18. The method of claim 17, further including fastening the insulator to the end of the cable with fastening means. Date: 23 May 2014