WO2005071795A1

WO2005071795A1 - Multi-outlet power cord

Info

Publication number: WO2005071795A1
Application number: PCT/AU2005/000085
Authority: WO
Inventors: David Hutchings
Original assignee: Tubing And Electrical Industries Pty Ltd
Priority date: 2004-01-27
Filing date: 2005-01-27
Publication date: 2005-08-04
Also published as: GB0411944D0; GB0415485D0; GB2410624A

Abstract

The present invention relates to an extension cord (14) that includes multiple outlets (32) at spaced apart distances there along. Each power outlet (32) has associated therewith its own circuit breaker which can be a safety-type circuit breaker such as a fuse or a manual circuit breaker such as a switch (38), such that when the circuit is broken either due to excessive current or manually, the electrical connection to the remaining power outlets of the cord is not affected. The present invention is useful both in small-scale applications such as a household for electrical devices such as vacuum cleaners, televisions and other electrical equipment, and also in larger scale environments such as building sites where multiple sockets may be required at spaced apart intervals in order to provide power to electrical devices such as drills and welding machines.

Description

Multi Outlet Power Cord

The present invention relates to a multi outlet power cord and, more specifically, to a power or extension cord including at least two sockets at spaced apart intervals along the length of the cord.

BACKGROUND OF THE INVENTION Extension cords are well known devices used for supplying power to electrical devices that are required to be used in locations some distance away from a power outlet or source. Extension cords typically comprise a male plug at one end, a female socket at the other end, and a length of wire connecting the two ends, the length of wire typically dependant upon the requirements of the user. The male plug of the extension cord is typically adapted to engage a female socket of a power outlet while a male plug of an electrical device is inserted into the female socket of the extension cord, thereby providing an electrical connection between the power source and the electrical device.

Extension cords are typically used both in household situations where an electrical device such as a vacuum cleaner is required to be powered a distance away from a power outlet typically situated on a wall of the house, and in large scale situations such as construction sites whereby electrical devices such as drills and welders are required to be used.

Regardless of the situation in which an extension cord is required, a common problem exists in that more than one electrical device is sometimes required to be used at any one instance and often at spaced apart intervals away from the power source.

Extension cords which include multiple female sockets do exist. For example, some extension cords include a multiple socket block connected at the end of a main cord for connection of one or more electrical devices thereto. In situations where a greater number of sockets are required at a further distance away, it is quite common for multiple extension cords of this type to be coupled together, despite the known safety risks associated with this course of action.

Those extension cords which include female sockets at spaced apart intervals along the length of the cord overcome some of the aforementioned problems. However, a primary drawback to these extension cords is the fact that in the event that a single socket along the length of the cord should fail, the remaining female sockets also fail due to the electrical wiring of the extension cords. For example, if a single socket were to draw an excess amount of current through the cord and thereby trip a circuit breaking means associated with the cord such as a fuse, current being drawn to the remaining sockets would also be stopped thereby rendering the entire cord unusable.

A further drawback to these types of cords is that if a user wishes to change appliances on a single socket, the power at the source must be switched off for safety reasons. This means that appliances being used in the remaining sockets of the cord are to be switched off also. This is an obvious problem in work sites where typically all of the sockets are in use. To overcome this problem, users tend to unplug the appliance and plug in the new appliance while the socket is still active, an obvious safety hazard.

It is therefore an object of the present invention to overcome at least some of the aforementioned problems or to provide the public with a useful alternative.

It is a further object of the present invention to provide a multi outlet power cord including at least two spaced apart sockets along the length of the cord whereby each socket has associated with it an independent circuit breaking means such that in the event that the circuit breaking means of a single socket is tripped or is disconnected, the remaining sockets of the extension cord will continue to operate safely.

SUMMARY OF THE INVENTION

Therefore in one form of the invention there is proposed a multi outlet power cord said power cord including: an electrical cord; a male plug in electrical connection with said electrical cord; and at least two female sockets in electrical connection with said cord, said sockets located at spaced apart intervals along said electrical cord whereby at least one of said sockets includes a circuit breaking means adapted to break electrical connection between said female socket and said electrical cord.

The present invention therefore provides for an extension cord that includes multiple power outlets at spaced apart distances therealong. Each power outlet has associated therewith its own circuit breaker which can be a safety-type circuit breaker such as a fuse or a manual circuit breaker such as a switch, such that when the circuit is broken, the electrical connection to the remaining power outlets of the cord is not affected.

In preference said circuit breaking means is a fuse adapted to break electrical connection between said female socket and said electrical cord when a predetermined level of current is drawn through said female socket.

Preferably said circuit breaking means is a switch which allows for a user to manually connect or disconnect electrical connection between said female socket and said electrical cord. This is advantageous in that one may manually activate or deactivate an individual power outlet on the cord without affecting electrical flow to the remaining power outlets.

Preferably said power cord includes a safety fuse in electrical connection with said switch so as to override said switch when a predetermined level of current is drawn through said female socket. This is important in that when the switch of the power outlet is manually switched on, excessive current may still be drawn therethrough and therefore having a backup safety fuse is essential.

In preference said switch includes an indication means of whether or not said female socket and said cord are in electrical connection. Advantageously at least one of said female sockets includes an identification means for displaying information relating to a feature of said socket.

In preference at least one of said female sockets includes a mooring means for mounting to a surface.

Preferably all of said female sockets include a mooring means in the form apertures that extend outwardly from each socket for insertion of a fixing means therethrough.

Advantageously said power cord allows for multiple values of voltage. For example, electrical appliances typically require a 120V source whereas others require higher amounts of up to 240V.

In preference said electrical cord has associated therewith a main circuit including an active, neutral and grounded wire. In preference said male plug is a 240V AC, 50Hz 3 -pin plug.

Preferably said electrical cord includes at least a first end and a second end said male plug associated with said first end and one of said female sockets associated with said second end.

In a further form of the invention there is proposed a multi outlet power cord including: an electrical cord with a first end, a second end and a male plug coupled to said first end thereof; and at least two receptacle blocks coupled to said electrical cord at spaced apart intervals therealong, each of said receptacle blocks including a corresponding female socket and a corresponding circuit breaking means associated therewith, said corresponding circuit breaking means adapted to break electrical connection between said corresponding female socket and said electrical cord.

Preferably said corresponding circuit breaking means is a fuse adapted to break electrical connection between said corresponding female socket and said electrical cord when a predetermined level of current is drawn through said corresponding female socket.

In preference said corresponding circuit breaking means is a switch which allows for a user to manually connect or disconnect electrical connection between said corresponding female socket and said electrical cord. In preference said power cord includes a safety fuse in electrical connection with said switch so as to override said switch when a predetermined level of current is drawn through said corresponding female socket.

Preferably said switch includes an indication means of whether or not said corresponding female socket and said cord are in electrical connection.

Preferably at least one of said receptacle blocks includes an identification means for displaying information relating to a feature of said receptacle block.

In a still further form of the invention there is proposed a multi outlet power cord of the type including a first active wire, a second neutral wire and a third grounded wire, and a male plug at one end thereof adapted to be connected to a power source to thereby draw electrical current through said electrical cord, said multi outlet power cord including multiple receptacle blocks disposed at substantially large spaced apart intervals along said electrical cord whereby each of said receptacle blocks includes a corresponding female socket and a corresponding circuit breaking means which are each electrically coupled to said electrical cord, said corresponding circuit breaking means adapted to disconnect said corresponding female socket from at least said first active wire when activated.

Preferably said corresponding circuit breaking means is in the form of a fuse which is activated when a predetermined level of current is drawn through said fuse to said corresponding female socket.

In preference said predetermined level of current is at or above a standard safety threshold.

Preferably said corresponding circuit breaking means is a switch which when pressed connects said corresponding female socket with said electrical cord and when depressed disconnects said corresponding female socket from said electrical cord.

Advantageously said switch includes a backup fuse which is triggered when current above a safety standard threshold is drawn therethrough.

In preference each of said multiple receptacle blocks includes an illumination means such as a light emitting diode (LED) which illuminates when the corresponding female socket is active.

Preferably each of said multiple receptacle blocks includes an identification means identifying a characteristic of said multi outlet power cord. Such a characteristic may be related to the circuitry of the electrical cord for example. 1 BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,

Figure 1 is a perspective view of a multi outlet power cord in accordance with the present invention;

Figure 2a is a top view of the multi outlet power cord of Figure 1;

Figure 2b is a side view of the multi outlet power cord of Figure 1 ;

Figure 3 is an enlarged perspective view of a single female socket of the multi outlet power cord of Figure 1;

Figure 4 is a perspective view of a multi outlet power cord in accordance with a second embodiment of the present invention; and

Figure 5 is an enlarged perspective view of a single female socket of the multi power outlet cord of Figure 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanying drawings.

Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Figures 1, 2a and 2b illustrate a multi outlet power cord 10 in accordance with the present invention. The power cord 10 includes a male plug 12 attached at one end thereof and a cord 14.

In the illustration, the male plug 12 is a 240V AC, 50Hz 3 -pin plug of the type commonly used in Australia. It is to be understood that the present invention is not intended to be limited to this type of male plug but may be adapted to include any other male plug available in other regions of the world. As mentioned, the male plug 12 includes three pins 16. Each pin is maintained in electrical connection with three separate wires, an active, neutral and grounded wire, all three wires being bound together into cord 14 and covered by an insulation material. The gauge of the active wire may vary depending on the expected use of the extension cord 10. The power cord 10 further includes three female sockets or receptacles 18, 20 and 22 disposed at intervals along the length of cord 14 whereby socket 22 defines the end of the cord 14. The length of the intervals may vary, however, it is preferable that they are evenly spaced apart. Associated with each female socket are mooring members 24 and identification mark 26, each of which will be described in more detail hereinbelow.

It is to be understood that the power cord 10 of the present invention may include any number of spaced apart female sockets and is not intended to be limited to any particular number of sockets. For example, in a household situation two to three spaced apart sockets may well suffice, however, larger scale situations may require the need for five or more sockets to be spaced apart along the cord 10. Those skilled in the art would realise that an electrical appliance (not shown), and more specifically, the male plug of an electrical appliance is adapted to be inserted into any one of the female sockets to thereby provide power to the electrical appliance some distance away from the power source (not shown). Typically, male plug 12 is inserted into a female socket of the power source.

Each female socket 18, 20 and 22 has its own fuse (not shown) associated therewith. Each fuse is adapted to break the circuit to its corresponding female socket should the current being drawn therethrough be excessive or above a predetermined level. Current safety standards around the world vary and it is to be understood that the level of current which triggers the fuse will correspond with the safety standards of a particular region in which the power cord 10 is being used. The fuse is arranged within the circuit such that in the event that it is tripped, it does not affect the flow of current to the remaining female sockets.

It is to be understood that circuit breaking means other than fuses may well be used, as will become obvious in the description of the second embodiment. In fact, excess current is not the only safety concern associated with extension cords. The female socket may well include alternate safety means to counteract these potential safety hazards, these safety means if used, also being arranged independent of the main circuit.

Referring now to Figure 3 there is shown an enlarged view of female socket 20. Socket 20 comprises a rigid block including engagement means 28 on its top surface for engagement with a male plug of an electrical appliance or the like. As previously mentioned, the female sockets each include two mooring members 24 which extend outwardly and oppositely from the base of the longitudinal sides of socket 20. The mooring members 24 include apertures for a bolt (not shown) or similar fixing means to extend therethrough and fix the female socket 20 to a surface, this being especially useful in larger scale use of the extension cord where free movement of the sockets may prove to be potentially dangerous. Each socket includes an identification mark 26 adjacent the engagement means 28 which serves to indicate information about the socket to a user. For example, in extension cords having multiple voltage capabilities such as 120/240V cords, the identification mark may indicate which circuit the female socket is in connection with so that the user may chose the correct socket in which to plug an electrical appliance in order to balance the power load of the circuit.

Typically, most of the outer parts of the extension cord are constructed from plastics or polymers for obvious safety reasons.

Existing extension cords typically have a single fuse or other precautionary means in association with the main electrical circuit of the cord. Therefore, if excessive current being drawn through one socket was to trigger the fuse, the main circuit is broken and hence flow of current to the remaining sockets is also broken. The extension cord of the present invention overcomes this problem in that each female socket has associated therewith its own fuse or other precautionary means so that if a single fuse were to be triggered, the main flow of current is not affected.

An example may involve an electrical appliance plugged into female socket 18 whereby for one reason or another, the appliance trips the fuse in the socket 18. In using the extension cord of the present invention, electrical appliances plugged into sockets 20 and/or 22 will not be affected. Where an electrical appliance such as a computer or television is plugged into socket 20 or 22, this is especially important in that if a single fuse affecting the main circuit is used, the computer, television or any other appliance being powered through the remaining sockets may be damaged in the process resulting in substantial repair cost to the user.

Figures 4-5 illustrate a second embodiment of the present invention. Cord 30 includes three identical sockets 32, 34 and 36 spaced apart at intervals as previously described. It is to be understood that some features of the cord 30 shown in Figures 4-5 are the same as hereinbefore described and these features are therefore referred to using the same reference numbers as used earlier. The second embodiment includes an alternate circuit breaking means in the form of switches. When the switch 38 is pressed into the ON position, it effectively creates a connection between the female socket to which it corresponds, with the main circuit. When the switch is depressed or in the OFF position, the connection between the socket and circuit is broken. This provides the user with the ability to manually break or connect flow of electricity to each individual socket of the cord 30 at his or her own will. The present invention is not to be limited to the use of single-pole switches only, which are only capable of making or breaking connection between one of the wires of the main circuit and the female socket, this typically being the active wire. For example, safety regulations may require that double-pole switches be incorporated into each receptacle so that connection between both the active and neutral wires and the female socket is controlled. The use of double-pole switches is typically as a safety precaution in case the neutral wire becomes active.

The ability to manually disconnect the socket from the main circuit provides the user with the assurance that when they wish to unplug an appliance or plug an appliance into a socket, there is no danger of the socket being active. This is especially useful when multiple sockets are in use. Rather than turning off the flow of electricity at the source which would affect appliances being used at the other sockets, one may now disconnect the flow of electricity at their own individual socket without disturbing the remaining sockets. The advantages of such a cord can be appreciated at work sites where multiple sockets are required to be used at one time and where safety is of utmost importance. It is to be understood that it is preferable for the female sockets 32, 34 and 36 to also include a fuse (not shown) that overrides the manual switch 38 for breaking the electrical connection. This is a further safety precaution for situations such as when excessive current is being drawn through a socket while the switch is manually turned on.

Also shown in Figures 4-5 is an LED 40 whereby when a switch is in the ON position, or when current is flowing to either of the female sockets, the LED 40 will illuminate for indicating to the user that the socket is active. It is to be understood that alternate visual indication means may be used. For example, the LED may be present as part of the switch itself.

Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

Dated this 25 January 2005

Tubing and Electrical Industries Pty Ltd By their Patent Attorneys LESICAR PERRIN

Claims

1. A multi outlet power cord said power cord including: an electrical cord; a male plug in electrical connection with said electrical cord; and at least two female sockets in electrical connection with said cord, said sockets located at spaced apart intervals along said electrical cord whereby at least one of said sockets includes a circuit breaking means adapted to break electrical connection between said female socket and said electrical cord.

2. A multi outlet power cord as in claim 1 wherein said circuit breaking means is a fuse adapted to break electrical connection between said female socket and said electrical cord when a predetermined level of current is drawn through said female socket.

3. A multi outlet power cord as in claims 1 or 2 wherein said circuit breaking means is a switch which allows for a user to manually connect or disconnect electrical connection between said female socket and said electrical cord.

4. A multi outlet power cord as in claim 3 wherein said power cord includes a safety fuse in electrical connection with said switch so as to override said switch when a predetermined level of current is drawn through said female socket.

5. A multi outlet power cord as in any one of claims 3 or 4 wherein said switch includes an indication means of whether or not said female socket and said cord are in electrical connection.

6. A multi outlet power cord as in any one of the above claims wherein at least one of said female sockets includes an identification means for displaying information relating to a feature of said socket.

7. A multi outlet power cord as in any one of the above claims wherein at least one of said female sockets includes a mooring means for mounting to a surface.

8. A multi outlet power cord as in any one of the above claims wherein all of said female sockets include said mooring means.

9. A multi outlet power cord as in any one of the above claims wherein said power cord allows for multiple values of voltage.

10. A multi outlet power cord as in any one of the above claims wherein said electrical cord has associated therewith a main circuit including an active, neutral and grounded wire.

11. A multi outlet power cord as in any one of the above claims wherein said male plug is a 240V AC, 50Hz 3 -pin plug.

12. A multi outlet power cord as in any one of the above claims wherein said electrical cord includes at least a first end and a second end said male plug associated with said first end and one of said female sockets associated with said second end.

13. A multi outlet power cord including: an electrical cord with a first end, a second end and a male plug coupled to said first end thereof; and at least two receptacle blocks coupled to said electrical cord at spaced apart intervals therealong, each of said receptacle blocks including a corresponding female socket and a corresponding circuit breaking means associated therewith, said corresponding circuit breaking means adapted to break electrical connection between said corresponding female socket and said electrical cord.

14. A multi outlet power cord as in claim 13 wherein said corresponding circuit breaking means is a fuse adapted to break electrical connection between said corresponding female socket and said electrical cord when a predetermined level of current is drawn through said corresponding female socket.

15. A multi outlet power cord as in claim 13 wherein said corresponding circuit breaking means is a switch which allows for a user to manually connect or disconnect electrical connection between said corresponding female socket and said electrical cord.

16. A multi outlet power cord as in claim 15 wherein said power cord includes a safety fuse in electrical connection with said switch so as to override said switch when a predetermined level of current is drawn through said corresponding female socket.

17. A multi outlet power cord as in any one of claims 15 or 16 wherein said switch includes an indication means of whether or not said corresponding female socket and said cord are in electrical connection.

18. A multi outlet power cord as in any one of the above claims wherein at least one of said receptacle blocks includes an identification means for displaying information relating to a feature of said receptacle block.

19. A multi outlet power cord of the type having an electrical cord including a first active wire, a second neutral wire and a third grounded wire, and a male plug at one end thereof adapted to be connected to a power source to thereby draw electrical current through said electrical cord, said multi outlet power cord including multiple receptacle blocks disposed at substantially large spaced apart intervals along said electrical cord whereby each of said receptacle blocks includes a corresponding female socket and a corresponding circuit breaking means which are each electrically coupled to said electrical cord, said corresponding circuit breaking means adapted to disconnect said corresponding female socket from at least said first active wire when activated.

20. A multi outlet power cord as in claim 19 wherein said corresponding circuit breaking means is in the form of a fuse which is activated when a predetermined level of current is drawn through said fuse to said corresponding female socket.

21. A multi outlet power cord as in claims 19 or 20 wherein said predetermined level of current is at or above a standard safety threshold.

22. A multi outlet power cord as in claim 21 wherein said corresponding circuit breaking means is a switch which when pressed connects said corresponding female socket with said electrical cord and when depressed disconnects said corresponding female socket from said electrical cord.

23. A multi outlet power cord as in any one of claims 19 or 22 wherein said switch includes a backup fuse which is triggered when current above a safety standard threshold is drawn therethrough.

24. A multi outlet power cord as in any one of claims 19-23 wherein each of said multiple receptacle blocks includes an illumination means such as a light emitting diode (LED) which illuminates when the corresponding female socket is active.

25. A multi outlet power cord as in any one of claims 19-24 wherein each of said multiple receptacle blocks includes an identification means identifying a characteristic of said multi outlet power cord.