GB2239648A

GB2239648A - An extension lead

Info

Publication number: GB2239648A
Application number: GB9026613A
Authority: GB
Inventors: Anthony Cartledge
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-12-08
Filing date: 1990-12-07
Publication date: 1991-07-10
Also published as: GB8927817D0; GB9026613D0

Abstract

An extension lead comprises an electric cable 4 and a coiled spring 6 for retracting the cable onto drum 10 within body 8 having handle 24. For location. the body has removable lawn spike 14, and rubber stud 16 for smooth surfaces. The body may be pivotally-mounted on a spiked base. There are disclosed a wall bracket (Fig. 10) and a clamp (Fig. 11) for mounting the body. The body may be stowed under a hatch in a table to provide a kettle lead (Fig. 13). The socket on the cable end can receive a 2-pin and a 3-pin plug (Fig. 9). The body encloses slip rings 36, 38 and brushes 40, 42 and has a switch 46 and a lock 12 operative to prevent cable retraction and possibly cable extension. <IMAGE>

Description

AN EXTENSION LEAD This invention relates to an extension lead.

Extension leads for electrical cables are well known. In the known extension leads, the electrical cable is manually pulled out and when it is desired to retract the electrical cable, the electrical cable is manually wound back into the extension lead. The manual winding of the electrical cable forms something of a nuisance. In addition, if the extension lead is being used to feed current to a moving piece of electrical apparatus, there often occur instances when a set amount of the electrical cable has been extended from the extension lead and then the moving piece of electrical equipment moves nearer to the extension lead and then there is excess electrical cable which can get in the way. A typical example is the use of an extension lead to feed power to an electric lawnmower.As the lawnmower is moving up and down the lawn, the lawnmower will at some point be farthest away from the extension lead and will thus need a maximum amount of cable, but the lawnmower will also be at some other point nearest to the extension lead and at this point the cable that has been extended gets in the way. The extended cable constantly needs to be pulled out of the way of the lawnmower and there is always a danger that the lawnmower will cut through the cable, with the consequent danger of electrocuting an operator of the lawnmower.

It is an aim of the present invention to obviate or reduce the above mentioned problems.

Accordingly, this invention provides an extension lead comprising an electrical cable and a return mechanism for automatically retracting the electrical cable.

The extension lead may comprise a body portion for housing the electrical cable and the return mechanism.

The extension lead may include a handle attached to the body portion.

The body portion may house a drum on which the electrical cable is wound, the drum being biased by the return mechanism to a position in which the electrical cable is retracted.

The return mechanism may comprise a spring reel.

Other types of spring mechanism may however be employed.

The extension lead may include locking means for preventing an extended length of the electrical cable from being automatically retracted by the return mechanism.

Thus the locking means may temporarily override the return mechanism. The locking means may operate to hold the electrical cable fast and so prevent it being retracted or extended, or alternatively the locking means may operate to prevent the electrical cable being retracted but to still allow the electrical cable to be further extended.

The extension lead may include retaining means for helping to retain the extension lead in position on a surface.

The extension lead may be used for providing power to a wide variety of electrically powered products and thus the extension lead may be used indoors and/or outdoors.

The particular type of retaining means employed will depend upon where the extension lead is to be used and for what particular electrical products or types of electrical products. For example, if the extension lead is to be used outdoors for use with electrical lawnmowers, electrical grass scarifiers or electrical lawn edge cutting machines, then the retaining means may be at least one spike for inserting into a lawn and holding the extension lead fast. Two or more spikes may be employed if desired. In instances where the retaining means is to be used indoors, for example in a home, workshop or factory, then the retaining means may be at least one rubber stud.

Two or more of the studs may be employed if desired. For use of the extension lead indoors or outdoors, the extension lead may be permanently or temporarily fixed to a wall. In this case, an electrical appliance could be fed with electrical power from a fixed position on the wall. Depending upon where the extension lead is to be used, the wall may be an interior or an exterior wall, for example a room or a corridor wall feeding electrical power to a floor polisher or a vacuum cleaner. The extension lead may also be mounted on a fence, post or other suitable and appropriate support surface. During the indoor or the outdoor use, the body portion will be kept remote from the electrically powered product.

The retaining means may be a changeable retaining means for enabling the extension lead to be used with different types of retaining means depending upon whether the extension lead is to be used indoors or outdoors.

Thus, for example, the retaining means may be a screw threaded retaining means such for example as at least one screw threaded spike or at least one screw threaded stud.

The spikes and studs can be interchanged as desired.

Preferably, the extension lead comprises retaining means in the form of at least one spike and retaining means in the form of at least one stud, the spike retaining means being mounted on a base, the spike retaining means being releaseably secured to the body portion of the extension lead, and the base being such as to prevent operation of the stud retaining means when the base is on the extension lead, and the base also being such that when it is removed from the extension lead, the stud retaining means is able to operate.

Advantageously, the base is a swivelling base which allows the body portion to swivel with respect to the spike, whereby the body portion can swivel such that the electrical cable is able to extend from the body portion always in the direction of the lawnmower or other garden care products that might be moving up and down a lawn and thus constantly changing direction with respect to the extension lead.

The extension lead will usually include an electrical input socket. The electrical input socket may be a three pin input socket or a two pin input socket as may be desired and appropriate.

As indicated above, the extension lead may be used to provide power to a wide variety of electrical products. The electrical products may be moving electrical products such for example as lawnmowers, floor polishers or concrete planing machines, or they may be relatively static electrical products such for example as table lamps or domestic kitchen appliances.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 is a cross section through a first extension lead; Figure 2 is a plan view of the extension lead as shown in Figure 1; Figure 3 shows the first extension lead in use; Figure 4 illustrates the operation of the first extension lead in the situation shown in Figure 3; Figure 5 is a cross section through part of a second extension lead; Figure 6 is a plan view showing the part of the extension lead shown in Figure 5; Figure 7 shows the underside of a housing for the extension lead; Figure 8 is a cross section through part of an extension lead; Figure 9 shows a dual purpose socket for forming part of the extension lead; Figure 10 shows a wall bracket for mounting the extension lead on a wall; ; Figure 11 shows a universal clamp for mounting the extension lead on a support member; Figure 12 shows an extension lead clamped to a work bench; Figure 13 shows an extension lead mounted beneath a work surface; Figure 14 shows apparatus for storing a small extension lead in a kitchen or other appropriate place; and Figure 15 is an enlarged cross section through part of the apparatus shown in Figure 14.

Referring to Figures 1 and 2, there is shown an extension lead 2 comprising an electrical cable 4 and a return mechanism 6 for automatically retracting the cable 4. The extension lead 2 also comprises a body portion 8 for housing the cable 4 and the return mechanism 6. The body portion 8 also houses a drum 10 on which the cable 4 is wound. The drum 10 is biased by the return mechanism 6 to a position in which the cable 4 is retracted.

The return mechanism 6 is formed by a flat spring reel.

The extension lead 2 includes locking means in the form of a locking button 12 for locking the drum 10.

The locking button 12 may be employed to override the return mechanism 6 and to prevent the cable 4 from being retracted around the drum 10 inside the body portion 8.

The extension lead 2 includes retaining means for helping to retain the extension lead 2 in position on a surface. Figures 1 and 2 show two types of retaining means. One type of retaining means is shown as a spike 14 for sticking in a lawn. The spike 14 will thus be used when the extension lead 2 is for outdoor use, for example with electrically powered lawn care products. Another type of retaining means is shown as a rubber stud 16. The stud 16 may rest on the surface of atable or other article inside a house and thus the stud 16 will be used when the extension lead 2 is to be used inside.

It will be noticed that the spike 14 and the stud 16 are each provided with a screw threaded shank portion 18 which enables the spike 14 or the stud 16 to be screwed into a screw threaded recess 20 in the body portion 8. The shank portion 18 terminates in a flat sided formation 22 which acts as a nut for receiving a spanner (not shown) for tightening and untightening the spike 14 or the stud 16.

The extension lead 2 is also provided with a handle 24 which upstands from the body portion 8 as shown in Figure 1. The handle 24 can be used for carrying the extension lead 2. The handle 24 is also useful for pushing the spike 14 into a lawn and pulling the spike 14 out of the lawn when it is desired to move the extension lead 2.

The extension lead 2 includes an electrical input socket in the form of a two pin socket 26 having apertures 28, 30 for receiving the two pins of a two pin plug 32 (see Figure 3) attached via a lead 34 to the mains electricity. The mains electricity can be obtained from any suitable socket, for example in a house or factory, or on an outside wall, fence, post, or other support surface. The socket will normally be a waterproof socket when it is mounted outdoors.

Electrical connections inside the body portion 8 include a pair of slip rings 36, 38 and a pair of brushes 40, 42. As can be seen from Figure 1, the brush 40 operates over the slip ring 36, and the brush 42 operates over the slip ring 38.

The body portion 8 has an aperture 44 through which the cable 4 passes. The body portion 8 also has an on/off switch 46. The switch 46 is effective to switch the electrical power to the extension lead 2 on and off.

Referring now to Figure 3, the extension lead 2 is shown in use on a lawn 48. A person 50 is shown mowing the lawn 48 with a lawnmower 52. Electrical power for the lawnmower 52 is provided via the lead 34 and the extension lead 2 having the cable 4. The cable 4 has a push in connector part 54 which connects to a complementary push in connector part 56 attached to a short lead 58 on the lawnmower 52.

Figure 4 shows how the extension lead 2 can be used in mowing the lawn 48. More specifically, the cable 4 can be pulled out of the extension lead 2 as the lawnmower 52 moves away from the extension lead 2 which is fixed by the spike 14 in the lawn 48. As the lawnmower 52 approaches the extension lead 2, the cable 4 is automatically retracted so that there is no loose cable for being run over by the lawnmower 52. There is no longer any need to flick the cable 4 out of the way as would be necessary without the extension lead 2. With the extension lead 2, the cable is automatically retracted under constant moderate tension.

As the lawnmower 52 moves up and down the lawn 48, the direction in which the cable 4 extends will vary. This may result in the cable 4 pulling on the remainder of the extension lead 2 and in particular causing the spike 14 to be pulled out of the lawn 48.

Any such pulling of the spike 14 out of the lawn 48 can be avoided or reduced by the arrangement shown in Figures 5 and 6. In Figures 5 and 6, similar parts as in Figures 1 - 4 have been given the same reference numerals for ease of comparison and understanding.

In Figures 5 and 6, there is shown retaining means in the form of the spike 14 and retaining means in the form of three studs 16, only one of which is shown. The spike 14 is mounted on a base 60. The base 60 is releaseably secured to the body portion 8 of the extension lead 2. This is effected by having the base 60 provided with side walls 62 so that the side walls 62 can fit around the body portion 8. The base 60 is provided with apertures 64 which allow finger-operated fasteners 68 which are held captive to the base 60 to simply be screwed into screw threaded recesses in the body portion 8 to secure the base 60 to the body portion 8. Thus no special tools are needed and the spike 14 can easily be secured in position on the body portion 8, or removed from the body portion 8.

The base 60 is provided with apertures 70 for enabling the base 60 to fit over the studs 16.

When the spike 14 is being used, the studs 16 are then not used. When the spike 14 removed from the body portion 8, the studs 16 are then available for use, for example for indoor use.

The spike 14 extends from a base plate 72. The base plate 72 is connected to the remainder of the base 60 by a swivel arrangement formed by bearings 74. The bearings 74 may be nylon ball bearings or any other desired and appropriate type of bearings. The bearings 74 enable the spike 14 and the base plate 72 to remain firmly fixed in a lawn whilst the remainder of the base 60 and the attached body portion 8 swivel. This swivelling is advantageous in that as the lawnmower 52 is moved up and down the lawn, the cable 4 will extend at different angles as shown in Figure 4. The body portion 8 can however swivel towards the direction of the lawnmower 52 so that the cable 4 can always exit cleanly from the body portion 8. Thus the cable 4 will not tend to pull unduly on the body portion 8 and thus on the spike 14. This in turn means that the spike 14 will not be pulled out of the lawn 48.

Referring now to Figure 7, there is shown the underside of a body portion 8. A base portion 76 is reset flush with the casing forming the body portion 8. The base portion 76 is. secured in position by two screws 78. The base portion 76 carries a ball race, for example including the bearings 74 shown in Figure 5, and it also carries the spike 14 or, alternatively, a threaded spigot.

Referring to Figure 8, there is shown in section the base portion 76 in Figure 7. Figure 8 also shows a ball race with bearings 74 and a threaded spigot 80 which can be used as an alternative to the spike 14.

The threaded spigot 80 is for use with the wall bracket shown in Figure 10 or the universal clamp shown in Figure 11.

Referring now to Figure 9, there is shown a dual purpose electrical socket 82 fitted to the cable 4. The socket 82 has a top surface 84 provided with three apertures 86 for receiving a 3-pin plug (not shown).The socket 82 also has an end wall 88 provided with two apertures 90 for receiving a 2-pin plug (not shown). The apertures 90 are'surrounded by a skirt portion 92.

Figure 10 is a perspective view showing a wall bracket 94 for use in mounting the extension lead of the invention in garages or workshops. The wall bracket 94 will usually be mounted adjacent an appropriate power point. The wall bracket 94 has a wall mounting flange 96 provided with appropriate apertures 98 for enabling the flange 96 to be secured by screws or other fixing means to a wall (not shown). An arm 100 extends from the flange 96 as shown and the arm 100 terminates in a post member 102. The post member 102 supports a mounting flange 104 which is for receiving the extension lead of the invention. The flange 104 is provided with mounting apertures 106. The flange 104 is pivotable about the post member 102 by means of a pivot screw 108.

Thus the extension lead can be rotated to any desired angle relative to the flange 96.

Referring now to Figure 11, there is shown a universal clamp 110. The clamp 110 enables an extension lead of the invention (not shown) to be fitted to any appropriate support member such for example as a timber framework-or scaffold tubing. The clamp 110 has a swivelling base plate 112 which is mounted to a swivelling member 114 that will move through 1800 and that can be locked in three positions The entire mechanism so far described will slide out from a tubular body 116 of a clamp portion including a fixed clamp arm 118 and a clamp screw 120. If the said mechanism is slid out from the tubular body 116, it can be twisted through 900 and locked into position. The locking mechanism comprises a sprung button 122 fixed to an inner tube 124, the inner tube 124 being attached to the mechanism, including the swivelling base plate 112 and the swivelling member 114.The button is able to protrude as shown through holes 126 in the tubular body 116.

The swivelling member 114 is able to be locked in its three positions by another sprung button 128 which can project through any one of three holes 130 in the swivelling member 114. The clamp screw 120 is screwed through a clamp arm 132 by screwing on a triangular shape member 134 as shown.

Figure 12 shows an extension lead 2 mounted by a clamp 136 to the back 138 of a work bench 140.

Persons can thus work on the work bench 140 with the required electrical power being supplied by the extension lead 2 for a wide variety of electrical tools such for example as routers, sanders and drills.

Trailing cables will no longer be a problem and a danger.

Referring now to Figure 13, there is shown a small extension lead 2 mounted underneath a kitchen work surface 142 and supplying electrical power to a kettle 144. Obviously, the kettle could be replaced by any other suitable and appropriate electrical appliance. The cable 34 receives mains power from a mains socket 146 located on a wall 148 at a position underneath the kitchen work surface 142. When the cable 4 is not being used, it can be retracted into the extension lead 2 and a cover 150 can be closed.

An advantage of the arrangement shown in Figure 13 is that every kitchen appliance need not be fitted with an individual power cable. Furthermore, safety is enhanced since there are no trailing leads for young children to pull, and possibly consequently scald themselves as may occur if, for example, the kettle 144 were to be full of boiling water. The cable 4 can be pulled out on a ratchet and retracted by pressing a release button.

As an alternative to the arrangement shown in Figure 13, the extension lead 2 may be mounted in the wall 148, especially if the wall 148 is a cavity wall.

Figures 14 and 15 show apparatus 152 for use in storing the cable 4 when the extension lead 2 is not in use. The apparatus 152 may be especially useful for use of the extension lead 2 in kitchens and in other domestic situations. As can be seen, a cover 150 closes down on a holder 154 which is shaped to receive an electrical socket 156, for example for use in plugging in the kettle 144 shown in Figure 13. The holder 154 has an opening 158 which allows the cable 4 to run freely through the holder 154. The holder 154 has a concave portion 160 which enables the socket 156 easily to be grasped by a personts fingertips. The cover 150 is provided with a hinge 162 which protects the socket 156 against damp, dust and similar adverse conditions.

If desired, the apparatus 152 may be provided with an on/off rocker switch (not shown).

As will be understood from the drawings, the various extension leads 2 of the present invention can be used in many applications and in many different environments. Electric power can be taken to a very wide variety of electrical appliances from a remote point, without the need for the appliances to carry unwieldy lengths of cable with the attendant problems of tripping over, pulling or cutting the cable.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected.

Thus, for example, the stud 16 may be made of a material other than rubber. Also, the socket 26 may be a three pin socket. Other types of return mechanisms 6 may be employed and the body portion 8 may be of a different shape to that shown. The lead 34 may be permanently connected to the extension lead 2, in which case the end of the lead 34 remote from the body portion 8 may be provided with a plug for fitting in a mains outlet socket.

The extension lead may be sold under the trade mark REFLEX.

Claims

1. An extension lead comprising an electrical cable and a return mechanism for automatically retracting the electrical cable.

2. An extension lead according to claim 1 in which the body portion houses the electrical cable and the return mechanism.

3. An extension lead according to claim 2 and including a handle attached to the body portion.

4. An extension lead according to claim 2 or claim 3 in which the body portion houses a drum on which the electrical cable is wound, the drum being biased by a return mechanism to a position in which the electrical cable is retracted.

5. An extension lead according to claim 4 in which the return mechanism comprises a spring reel.

6. An extension lead according to claim 5 and including locking means for preventing an extended length of the electrical cable from being automatically retracted by the return mechanism.

7. An extension lead according to claim 6 in which the locking means is such as temporarily to override the return mechanism.

8. An extension lead according to claim 6 or claim 7 in which the locking means is such as to hold the electrical cable fast and so prevent it being retracted or extended.

9. An extension lead according to claim 6 or claim 7 in which the locking means is such as to prevent the electrical cable being retracted but to still allow the electrical cable to be further extended.

10. An extension lead according to any one of the preceding claims and including retaining means for helping to retain the extension lead in position on a surface.

11. An extension lead according to claim 10 in which the retaining means is at least one spike.

12. An extension lead according to claim 10 in which the retaining means is at least one rubber stud.

13. An extension lead according to any one of claims 10 to 12 in which the retaining means is a changeable retaining means for enabling the extension lead to be used with different types of retaining means depending upon whether the extension lead is to be used indoors or outdoors.

14. An extension lead according to claim 13 in which the changeable retaining means is a screw threaded retaining means.

15. An extension lead according to claim 13 or claim 14 and comprising retaining means in the form of at least one spike and retaining means in the form of at least one stud, the spike retaining means being mounted on a base, the spike retaining means being releaseably secured to the body portion of the extension lead, and the base being such as to prevent operation of the stud retaining means when the base is on the extension lead, and the base also being such that when it is removed. from the extension lead, the stud retaining means is able to operate.

16. An extension lead according to claim 15 in which the base is a swivelling base which allows the body portion to swivel with respect to the spike.

17. An extension lead according to any one of the preceding claims and including an electrical input socket.

18. An extension lead according to claim 17 in which the electrical input socket is a socket having a 3-pin input socket portion, and a 2-pin input socket portion.

19. An extension lead substantially as herein described with reference to the accompanying drawings.