AU2005205814A1 - Lockout Device for Electrical Equipment - Google Patents

Description

LOCKOUT DEVICE FOR ELECTRICAL EQUIPMENT FIELD OF THE INVENTION 00 This invention relates to devices, especially tags, that can be secured N to a plug of an item of electrical equipment to indicate the reason why the Sequipment should not be used, and additionally to prevent use of the N equipment until it is repaired or tested.

BACKGROUND

Many industrial and domestic accidents are caused by the application or release of energy in an inadequately controlled or uncontrolled manner.

Mains-powered electrical equipment is notoriously involved in a substantial proportion of such accidents.

When it is found that an electrical appliance or other lectrical equipment is unserviceable or otherwise in a condition where it should not be used, it is desirable (and in industry considered essential) to apply a tag to it to indicate that it should not be used, and display all appropriate information, and/or to utilize some form of "lockout" device to prevent its being used. Such precautions may be applied additionally to other measures such as physical isolation of the equipment, where this is practicable.

Many devices have been developed to carry out both indicating and lockout functions. However, devices providing a lockout function in particular are often quite expensive and elaborate, particularly those involving keys and locks. Applicant has perceived a need for a device with both indicating and lockout functions that is very simple and inexpensive, and suitable for use with appliances and tools having mains power cables with plugs. Physical isolation and tagging are most often used where such items are found unserviceable, rather than comparatively expensive and elaborate lockout devices. The invention provides an inexpensive way to both tag and lock out such equipment and offers a useful alternative to potential users.

SUMMARY OF THE INVENTION

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The invention provides a device for preventing use of an item of electrical equipment. The device is to be used by being secured to a power plug of the item of equipment and when so secured by preventing the plug being plugged into a mating socket far enough for power to flow to the equipment. There are believed to be at least two distinctly inventive aspects to the invention. In both aspects the device preferably has a surface that when the device is secured to a power plug can be written on by a user for informative purposes. That or another surface of the device may also have printed, embossed or other suitably applied markings such as instructive or warning text or the like.

According to the invention in a first aspect, there is provided a device for preventing use of an item of electrical equipment including: a first component having an opening within which at least one pin of a power plug of said item of electrical equipment is receivable so that said at least one pin is prevented by said component from being entered far enough into a pin-receiving part of a power point or socket to allow electric power to flow into said plug; and securing means for securing said first component in a position on said plug where said at least one pin is received in said opening.

In the preferred embodiment, the said first component includes a tab, the tab having a first position extending into said opening and in use of the device being deformed by a said pin entering the opening so that the tab takes up a second position adjacent the pin.

Preferably, the tab in the second position is so located as to prevent the pin from fully entering the pin-receiving part of the said power point or socket.

It is particularly preferred that the said opening is one of a plurality of openings each of which in use receives at least one pin of the said power plug.

In a preferred embodiment, the said first component includes a tag formed from flexible sheet material that when secured to said plug is wrapped at least partially around said plug, said opening being formed in said tag.

The said tag may be marked and/or able to be marked on its surface

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Sby a user with textual and/or graphical material. For example, the tag may have words such as "WARNING: DO NOT USE" permanently marked on its surface and a space for a user to fill in details with a pencil, pen, marker pen or the like.

In any of the forms disclosed above, preferably said securing means includes two elongate tongues extending from said tag said tongues being adapted to be passed by a user into and retained within cooperating openings 00 in the device whereby to secure said device to said plug with said tongues positioned on opposite sides of a cord entering said power plug.

At least one of said tongues may include serrations that when said N tongue is passed into a said cooperating opening cooperate with a formation in said opening to prevent withdrawal of said tongue from said opening.

According to the invention in a second aspect, there is provided a device for preventing use of an item of electrical equipment including: a first component securable on a power plug of said item of electrical equipment and adapted to prevent pins of said plug from being entered far enough into pin-receiving parts of a power point or socket to allow electric power to flow into said plug; and securing means for securing said component on said plug, wherein said securing means includes two elongate tongues extending from a part of said device that includes said first component said tongues being adapted to be passed by a user into and retained within cooperating openings in the device whereby to secure said device on said plug with said tongues positioned on opposite sides of a cord entering said power plug so that said device is captive on said plug.

Preferably, at least one of said tongues includes serrations that when said tongue is passed into a said opening cooperates with a formation in said opening to prevent withdrawal of said tongue from said opening.

In a particularly preferred embodiment, said first component includes or is included in a tag formed from flexible sheet material that when secured to said plug is wrapped at least partially around said plug.

In order that the invention may be better understood it will now be

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Sdescribed non-limitingly by reference to preferred embodiments as shown in the attached Figures, of which: Figure 1 is an elevation of a safety tag according to the invention; Figure 2 is a plan view of an electrical appliance plug fitted with the tag shown in Figure 1; Figure 3 is a side elevation of the plug and tag shown in Figure 2, as seen looking in the direction of arrow Figure 4 is an end view of the plug and tag shown in Figure 2, as seen N 10 looking in the direction of arrow Figure 5 is a plan view of an electrical appliance plug fitted with an alternative tag according to the invention; Figure 6 is a perspective view of an electrical appliance plug fitted with a further tag according to the invention; Figure 7 is a perspective view of another alternative tag according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Figurel shows an electrical equipment safety tag 1 embodying the invention. Tag 1 is formed from a flexible and resilient sheet material, preferably a plastics material such as polypropylene, although it is not intended to preclude the use of any other suitable material. Tag 1 has an elongate main section 2 and two parallel tongues 3 and 4 extending lengthwise from one end 5 of the main section 2. Each of tongues 3 and 4 has several teeth 6 integrally formed along one edge. Penetrating main section 2 near its opposite end 7 are slots 8. Slots 8 are arranged in longitudinally spaced-apart pairs, and the slots 8 of each pair are suitably transversely positioned on main section 2 to receive tongues 3 and 4 as further described below.

Two further openings 9 and 10 are provided in main section 2. Opening 10 is elongate and channel-shaped, to define three sides 13, 14 and 15 of a rectangular tab 16 that is integral with main section 2. A fold line 17 defines a fourth side of the tab 16 and is shown in Figure 1 by a chain dotted line. An actual fold may be made along line 17 during manufacture of tag 1, so that line 17 defines in effect a hinge line about which tab 16 can rotate in use of

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Sthe tag 1. The purposes of openings 9 and 10 are described below.

Away from the slots 8 and openings 9 and 10, one surface 11 of tag 1 is provided with markings 12 that define a warning message and spaces for the entry by a user of information about the equipment onto which tag 1 is placed. Markings 12 may be provided by any suitable means. For example, markings 12 may be printed on tag 1 by any process suitable for the material Sof which tag 1 is made, or printed on paper (or other suitable) labels which are 00 Sin turn glued to tag 1. Another possibility is for tag 1 to be made of paper or N 10 card (not shown separately), marked with the markings 12, and thereafter Oformed into a flexible and resilient laminate with transparent plastics layers on c each face, in well-known manner. The precise nature of the markings 12 shown in Figure 1 is not intended to be limiting. Any other suitable or necessary markings 12 may be provided. Markings 12 are omitted from Figures 2 4 for clarity.

Figures 2, 3 and 4 show the tag 1 in use to both label, and physically prevent the use of, a mains power plug 20 of an item of electrical equipment (not shown) having a power cable 21.

To use the tag 1, earth pin 22 of plug 20 is first pushed through opening 9. Opening 9 is preferred to be a snug fit on earth pin 22 and is so shown in the Figures. As this is done, the remaining pins 23 of plug 20 bear against tab 16 so that it rotates about line 17. Pins 23 thus enter a rectangular opening 24 left in main section 2 as tab 16 rotates out of the plane of main section 2. Opening 24 (which includes opening 10) preferably has such a width as to fit snugly across the overall width of the pair of pins 23, and is so shown. As pins 23 pass into opening 24, tab 16 is bent progressively until its side (edge) 14 bears against face 25 of plug 20 preventing further movement of pins 23 into opening 24. Tab 16 is sufficiently stiff that it does not then buckle, instead holding surrounding area 26 of main section 2 away from face 25. Preferably, tag 1 is thick enough and its stiffness and resilience such that the contact between edge 14 and pins.23 tends to prevent pins 23 leaving opening 24.

Next, as shown in Figures 2 4, the user bends main section 2 around the body 27 of plug 20 and inserts each of tongues 3 and 4 into one of a 6 selected pair of the slots 8, with tongue 3 passing on an opposite side of cable 21 from tongue 4. The maximum widths of tongues 3 and 4, measured over $4 their respective teeth 6, are greater than the lengths of the slots 8. Thus, tongues 3 and 4 distort to permit their passage through slots 8, but once at least one tooth 6 of a tongue 3 or 4 has passed through its slot 8, that tongue 3 or 4 cannot readily be withdrawn. Accordingly tag 1 is held captive on plug and, when a sufficient length of each of tongues 3 and 4 has been pulled 00oO through tag 1, cannot be removed from earth pin 22 or pins 23 except by damaging the tag 1.

Tab 16 is so dimensioned that when tag 1 is secured to plug 20 as Sshown in Figures 2 to 4, enough of the length of each pin 23 is prevented from N entering a power point (not shown) that they cannot be pushed far enough into a power point (not shown) for power to flow to the appliance.

In Figures 2, 3 and 4 tab 16 is shown extending from its hinge linel7 inwardly towards plug 20. However, it will be apparent that tag 1 still works if, in use of device 1, tab 16 is instead bent the opposite way, so as to extend away from plug 20 and outwardly along the lengths of pins 23. In Figure 3 only, item 16a shows (in chain-dotted lines) tab 16 bent in this alternative way.

In this case, tab 16 simply bears against the front face of any socket into which a person might attempt to push the plug 20, thus still preventing power flow through plug With suitable explanatory text written on the tag, it will be seen that the appliance is not authorized for use and without damaging the tag 1 cannot in fact be used. Various shapes and sizes are found in the bodies of plugs, and so tag 1 is provided with several pairs of slots 8 and sufficient length in tongues 3 and 4 to accommodate a suitable range of plug designs.

Various modifications may be made to the tag 1 described above, if desired. For example, Figure 5 shows, on a plug 31, a modified tag 30 the same as tag 1 save for having scores 32 extending transversely fully across main section 2 at two locations, so that central part 33 of tag 30 has less curvature in use than area 26 of tag 1. Corresponding to tab 16 of tag 1 is a tag 34 Tag 1 is shown in a form suitable for use with a standard Australian 240V mains plug. However, it could be made with modified openings 9 and 10 to suit Australian 15A plugs (which have a wider earth pin Sthan 10A plugs) or the different pin sizes and configurations of other countries' $4 plug designs. Of course, it will be apparent to persons skilled in the art that C. tag 1 could as well be used with a two-pin plug (as found on double-insulated appliances) as on the three pin plug Teeth such as teeth 6 could be provided on both sides of tongues 3 and 4 instead of one side only, if required. Another possibility is to provide a 0 tag 40, shown in Figure 6, similar to tag 1 in having openings 46 and 47 corresponding to openings 9 and 10, respectively, but with flat tongues 41 each having serrations 43 on one face 44, and integrally formed co-operating Sformations 45 that receive tongues 41. The formations 45 and tongues 41 Swould be similarly proportioned to, and operate in the same way as, the serrated plastics cable ties that are well known in the electrical art. (That is, a tongue 41 can be pushed through a formation 45, but cannot be withdrawn.) Tag 40 could not be made from sheet material, but could for example be injection moulded in a suitable plastics material.

A further possibility is shown is Figure 7. Tag 50 has no integrally formed tongues, but instead electrical cable ties 51 of well-known type are threaded through slots 52. Tag 50 has openings 53 and 54 corresponding in function to openings 9 and 10, respectively, and a tab 55 corresponding to tab 16, of tag 1.

Other possible variations will be apparent and may be made without departing from the spirit or scope of the present invention.

Claims (17)

1. A device for preventing use of an item of electrical equipment including: a first component having an opening within which at least one pin of a power plug of said item of electrical equipment is receivable so that said at least one pin is prevented by said component from being 0 entered far enough into a pin-receiving part of a power point or socket to allow electric power to flow into said plug; and securing means for securing said first component in a position on said plug where said at least one pin is received in said opening.

2. A device according to claim 1 wherein the said first component includes a tab, the tab having a first position extending into said opening and in use of the device being deformed by a said pin entering the opening so that the tab takes up a second position adjacent the pin.

3. A device according to claim 2 wherein the tab in the second position is so located as to prevent the pin from fully entering the pin-receiving part of the said power point or socket.

4. A device according to any one of claims 1 to 3 wherein the said opening is one of a plurality of openings each of which in use receives at least one pin of the said power plug.

A device according to any one of claims 1 to 4 wherein said first component includes a tag formed from flexible sheet material that when secured to said plug is wrapped at least partially around said plug.

6. A device according to claim 5 wherein said opening is formed in said tag.

7. A device according to claim 5 or 6 wherein said tag is marked and/or able to be marked on its surface by a user with textual and/or graphical material.

8. A device according to any one of claims 1 to 7 wherein said securing means includes two elongate tongues extending from said tag said tongues being adapted to be passed by a user into and retained within cooperating openings in the device whereby to secure said device to said plug with said tongues positioned on opposite sides of a cord entering said power plug.

9. A device according to claim 8 wherein at least one of said tongues has serrations that when said tongue is passed into a said cooperating opening cooperate with a formation in said opening to prevent withdrawal of said tongue from said opening.

A device for preventing use of an item of electrical equipment including: a first component securable on a power plug of said item of electrical equipment and adapted to prevent pins of said plug from being entered far enough into pin-receiving parts of a power point or socket to allow electric power to flow into said plug; and securing means for securing said component on said plug, wherein said securing means includes two elongate tongues extending from a part of said device that includes said first component said tongues being adapted to be passed by a user into and retained within cooperating openings in the device whereby to secure said device on said plug with said tongues positioned on opposite sides of a cord entering said power plug so that said device is captive on said plug.

11. A device according to claim 10 wherein at least one of said tongues includes serrations that when said tongue is passed into a said opening cooperates with a formation in said opening to prevent withdrawal of Ssaid tongue from said opening. V,

12. A device according to claim 10 or 11 wherein said first component includes or is included in a tag formed from flexible sheet material that when secured to said plug is wrapped at least partially around said plug. 00

13. A device according to claim 12 wherein the tag is marked or able to be marked by a user with textual or graphic material.

14. A device for preventing use of electrical apparatus substantially as described herein by reference to attached Figures 1 to 4.

15. A device for preventing use of electrical apparatus substantially as described herein by reference to Figure

16. A device for preventing use of electrical apparatus substantially as described herein by reference to Figure 6.

17. A device for preventing use of electrical apparatus substantially as described herein by reference to Figure 7.