GB2445428A

GB2445428A - Protecting electrical street furniture

Info

Publication number: GB2445428A
Application number: GB0704850A
Authority: GB
Inventors: Paul David Chaplin; Ken Ree Wang; Craig Tomas Williams; David Steele
Original assignee: Aluminium Lighting Co Ltd
Current assignee: Aluminium Lighting Co Ltd
Priority date: 2007-01-05
Filing date: 2007-03-13
Publication date: 2008-07-09
Also published as: WO2008081194A1; GB0700200D0; EP2118378A1; GB0704850D0

Abstract

An item of street furniture, such as a lamp post 11 or an illuminated road sign, has an electrical coupling 108 to provide power to an electrical load such as a light. The coupling may be remote from the item and is preferably underground. If the item is damaged in an accident, the coupling is pulled apart, for example by a lanyard 103, so that the damaged item contains no electrically live parts. The invention may be supplied as a kit. A similar arrangement may also be used to separate oil pipes.

Description

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Street furniture

The present invention relates to street furniture,

especially (but not exclusively) lamp-posts, road signs and 5 the like.

Many items of street furniture are provided with some form of electrical load, typically in the form of a source of light. An electrically conductive cable extends to the 10 electrical load from a power supply located near to the item. For example, conventional lamp-posts have an electrical load in the form of a lamp which is usually mounted at or towards the top of the post. The lamp is connected via one or more electrically conductive wires to a 15 power supply located near to the post.

Certain items of street furniture such as lamp-posts are often arranged to topple and/or be moved from their mountings when they are struck by a vehicle to ensure that a 20 large proportion of the energy from the impact is dissipated in moving or toppling the lamp-post, so that a large amount of energy is not transferred to the vehicle. Such toppling or dismounting of the post may cause breakage of the wires carrying electricity from a power supply to the lamp or may 25 cause removal of the wires from connectors (if such connectors are used), thereby leaving exposed, live electrical wires. Such wires are an electrocution and ignition hazard at the scene of an accident and pose risks to occupants of vehicles, emergency personnel and those 30 charged with reconnecting the wires. Furthermore,

reconnection of the wires is time-consuming and expensive.

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Several systems are available which purport to deal with the problems with conventional lamp-posts. The Dot Plug system (INGALEPS, Queensland 4106, Australia) provides an abrupt release electrical coupling located above-ground at the base 5 of the lamp-post. The electrical connector has two parts, a male part that is connected to a lamp and a female part that is connected to a power supply located near to the post. Under normal operating conditions, the male and female parts are mated together to permit electrical power to be supplied 10 to the lamp from the power supply. When the post is struck by a vehicle, the movement of the lamp-post causes the male and female parts to be parted, cutting the electrical supply to the lamp. There are no bare wires or protruding electrically live parts, but the female part of the 15 electrical coupling remains electrically live and is located at the crash site.

GB1286078 discloses an abrupt release electrical coupling having two parts that are held together in an electrically 20 conducting arrangement by a breakable ring. If the ring is broken (for example, as a result of vehicular impact), a spring arrangement urges the two parts of the coupling away from one another so that electrical contact is broken. Such couplings may be used in street lights and bollards.

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US5335160 and US2004/0037084 each disclose a lamp-post with a spontaneous release coupling located above ground in the lower portion of the post. When the post is struck by a vehicle, movement of the post causes the two parts of the 30 coupling to be pulled apart so that the electrical supply to the lamp is cut-off. At least one of the two parts of the coupling is located within a chamber or box so that it is

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inaccessible even if the upper part of the post has been removed from its mountings by an impact.

DE2830876 discloses a lamp-post with a spontaneous-release 5 two-part coupling located in the post. When the post is struck by a vehicle, the two parts of the coupling are pulled apart so that the electrical supply to the lamp is cut-off. The part of the coupling connected to the power supply is located within a chamber or box provided with a 10 spring-loaded lid so that when the coupling is pulled apart, the spring-loaded lid covers the part of the coupling still connected to the power supply, therefore inhibiting access to the electrically-active part of the coupling.

15 In all of these devices, an electrically live half of the electrical coupling is located at the crash site.

The street furniture in accordance with the present invention mitigates against one or more of the problems 20 presented in relation to the prior art.

In accordance with a first aspect of the present invention, there is provided an item of street furniture comprising an electrical coupling and a body that, in a normal operating 25 position, projects above a surface, the item of street furniture being, in use, provided with an electrical load,

the electrical coupling comprising a first part which is, in use, associated with the electrical load and a second part 30 which is, in use, associated with a power supply, the first and second parts being arranged so that application of a force above a threshold level causes relative movement

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between the first and second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in which the load is, in use, electrically isolated from a power supply

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wherein in the event that the body, or part thereof, is displaced by more than a threshold displacement from a normal operating position then this displacement causes relative movement of the first and second parts of the 10 electrical coupling from the first position to the second position and wherein the electrical coupling is remote from the body.

This aspect of the present invention provides an item of 15 street furniture that may be safer than the prior art street furniture.

It is preferred that the first part is movable relative to the second part from the first position to the second 20 position.

The item of street furniture may be provided with a connecting member coupling the electrical coupling and the body such that displacement of the body, or part thereof, 25 from a normal operating position transmits a force via the connecting member to the electrical coupling. If the displacement of the body, or part thereof, from a normal operating position is above a threshold displacement, then a force is transmitted via the connecting member to the 30 electrical coupling to cause relative movement of the first and second parts of the electrical coupling from the first

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(connective) position to the second (non-connective) position.

The connecting member may comprise a line or the like. The 5 connecting member may comprise an electrical flex or cord or supplying electrical power to the electrical load. Alternatively, a line other than an electrical flex or cord for supplying electrical power to the electrical load may be used. The use of a line other than a flex or cord for 10 supplying electrical power may allow the power flex to be strain-relieved to inhibit damage to the power flex that may be caused by displacement of the body (or part thereof).

It is preferred that a portion of the connecting member 15 (such as a line) may be associated with a portion of the body. For example, the portion of the connecting member may extend through a cavity formed in the portion of the body. If said portion of the body has a longitudinal axis, then it is preferred that said portion of the connecting member is 20 spaced from the longitudinal axis.

The item of street furniture may comprise a tensioning arrangement for applying a force to the coupling, the tensioning arrangement comprising one or more tensioned 25 members which are, when the body is in a normal operating position, under tension, said tension exerting a force on the electrical coupling, wherein the tensioning members are arranged so that in the event that the body, or part thereof, is displaced by more than a threshold displacement 30 from a normal operating position, then this displacement causes an increase in tension in at least one of the tensioned members sufficient to causes relative movement of

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the first and second parts of the electrical coupling from the first position to the second position. This provides an efficient mechanism for breaking the electrical connection between the electrical load and a power supply. The force 5 applied to the electrical coupling when the body is in a normal operating position is clearly less than that required to move the first and second parts of the electrical coupling from the first to the second position.

10 The force applied to the electrical coupling when the body is in a normal operating position may be a tensile force.

The first part of the electrical coupling may be movable relative to the second part of the electrical coupling body 15 from the first position to the second position by the application of a tensile force to the coupling. This is a convenient coupling arrangement. When such an arrangement is used, it is preferred that when the body is in a normal operating position a tensile force is applied to the 20 electrical coupling. This presents an item of street furniture with an efficient decoupling mechanism.

In accordance with a second aspect of the present invention there is provided an item of street furniture comprising an 25 electrical coupling and a body that, in a normal operating position, projects above a surface, the item of street furniture being, in use, provided with an electrical load,

the electrical coupling comprising a first part which is, in 30 use, associated with the electrical load and a second part which is, in use, associated with a power supply, the first part and second parts being arranged so that the application

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of a force above a threshold level causes relative movement between the first part and the second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in 5 which the load is, in use, electrically isolated from a power supply the item of street furniture further comprising a tensioning arrangement for applying a force to the coupling, the 10 tensioning arrangement comprising one or more tensioned members which are, when the body is in a normal operating position, under tension, said tension exerting a force on the electrical coupling, wherein the tensioning members are arranged so that in the event that the body, or part 15 thereof, is displaced by more than a threshold displacement from a normal operating position, then this displacement causes an increase in tension in at least one of the tensioned members sufficient to causes relative movement of the first and second parts of the electrical coupling from 20 the first position to the second position.

This aspect of the invention presents an item of street furniture with an efficient decoupling mechanism.

25 It is preferred that the first part is movable relative to the second part from the first position to the second position.

It is preferred that the electrical coupling is remote from 30 the body. The item of street furniture in accordance with the second aspect of the present invention in particular facilitates the efficient movement of the first and second

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parts of the electrical coupling into the second position when the electrical coupling is remote from the body.

Those skilled in the art will realise that the electrical 5 load and power supply mentioned above in relation to the items of street furniture in accordance with the first and second aspects of the present invention are not necessarily part of the invention.

10 For the avoidance of confusion, the statements below relate to items of street furniture in accordance with the first and/or second aspects of the present invention.

The phrase "first part which is, in use, associated with the 15 electrical load" indicates that, in use, the first part of the electrical coupling may be electrically connected to the electrical load. This means that, when the coupling is in the first position, electrical power may be transmitted via the first part of the coupling to the electrical load.

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The phrase "a second part which is, in use, associated with a power supply" indicates that, in use, the second part of the electrical coupling may be electrically connected to the power supply. This means that, when the coupling is in the 25 fir'st position, electrical power may be transmitted to the second part of the coupling from the power supply.

Whilst it is preferred that the first part of the coupling is movable relative to the second part of the coupling from 30 the first position to the second position, the second part of the coupling may be movable relative to the first part from the first position to the second position.

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The item of street furniture may comprise an electrical load. The item of street furniture may comprise a power 5 supply.

The body may be adapted to topple or be displaced from its mountings in the event of an impact from a vehicle.

10 The body may support the electrical load, if present.

The two parts of the electrical coupling may be readily moved relative to one another from the second position to the first position, and retained in the first connective 15 position until forced apart once more by the application of a force above the threshold level.

One of the first and second parts of the electrical coupling preferably comprises a female socket and the other of the 20 first and second parts of the electrical coupling preferably comprises a male plug. The socket and plug mate together when the electrical coupling is in the first position to provide electrically-conductive contact between the first and second parts of the electrical coupling.

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Those skilled in the art will realise that the item of street furniture may be arranged such that small displacements of the body (or part thereof) do not cause the relative movement of the first and second parts of the 30 electrical coupling into the second (non-connective)

position. This may be the case if the body is struck by a small force. "Small" in this case means displacements that

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are smaller than the threshold level for causing the relative movement of the first and second parts into the second (non-connective) position.

5 Displacement of the body (or part thereof) from the normal operating position may be achieved by the body being struck, for example, by a vehicle or other object (such as a falling tree) and may also be achieved by severe weather (for example, strong winds).

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The term "street furniture" refers to any objects or equipment items that are suitable (or intended) for use on or near to a roadway or other spaces used by land-borne vehicles. Street furniture includes lamp-posts (possibly 15 fitted with an electrical lamp), road signs (possibly fitted with a lamp for illuminating the sign or an electrical display system for displaying warning messages or the like) , bus stops (possibly fitted with one or more electrical lamps and/or an electrical display system), illuminated bollards 20 (such as keep left signs), phone boxes or telephone booths (optionally fitted with electrical lamps), traffic lights, traffic signals, runway approach lighting standards and runway beacons.

25 The tensioning arrangement may provide the connecting member defined with respect to the item of street furniture in accordance with the first aspect of the present invention.

One of the tensioned members may comprise an electrical flex 30 or cord connected to the first part of the coupling. This facilitates a very simple arrangement in which the electrical flex or cord connected to the first part of the

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coupling is in tension, therefore removing the need for other tensioned members.

It is preferred that the item of street furniture comprises 5 a plurality of tensioned members, more preferably three or more tensioned members. Generally, there will be one particular direction from which items of street furniture are more likely to be hit by vehicles. This "usual direction" may correspond, for example, to the general 10 direction of traffic flow near to the item of street furniture. An item of street furniture in accordance with the first and second aspects of the present invention may be optimised to respond to vehicular impact from the usual direction. An increased number of tensioned members may make 15 the decoupling arrangement more responsive to impacts from directions other than the usual direction of impact.

The body may have an impact zone, the impact zone being a portion of the body between a lower impact limit defined as 20 the lowest part of the body that may reasonably be struck by a ground-travelling vehicle when the body is in a normal operating position and an upper impact limit defined as the highest part of the body that may reasonably be struck by a ground-travelling vehicle when the body is in a normal 25 operating position. For the avoidance of confusion, it is hereby stated that the impact zone also comprises the space inside a hollow body, the space being that between the lower impact limit and the upper impact limit. It is preferred that at least one of the tensioned members (preferably more 30 than one of the tensioned members and more preferably all of the tensioned members) extends into the impact zone. It is preferred that at least one of the tensioned members

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(preferably more than one of the tensioned members and more preferably all of the tensioned members) extends from the lower impact limit to the upper impact limit. It is possible for one or more of the tensioned members to extend below the 5 lower impact limit and above the upper impact limit. It is preferred that the lower impact limit is from 0 to 50cm above the ground, more preferably from 0 to 20cm above the ground. It is preferred that the upper impact limit is from lm to 2m above the ground and preferably from 1.3m to 1.8m 10 above the ground.

As mentioned above, it is anticipated that at least a portion of the body may be hollow and at least one of the tensioned members may extend into the hollow portion.

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It is preferred that the body comprises a wall and at least one of the tensioned members (preferably more than one and more preferably each of the tensioned members) is located close to the wall. It has been found that decoupling of the 20 first and second parts of the electrical coupling is more efficient if the tensioned members are close to the wall. It is preferred that the shortest distance between the wall and at least one of the tensioned members is smaller than the shortest distance between the said at least one of the 25 tensioned members and the centre of the body. The centre of the body is typically defined by a longitudinal axis of the body. For example, the centre of the body may be the longitudinal axis of a substantially cylindrical portion of a post through which the tensioned member extends. 30 Therefore, if the portion of the body associated with the at least one tensioned members has a longitudinal axis, then it is preferred that at least one of the tensioned members is

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spaced from the longitudinal axis. It is preferred that more than one (and further more preferred that each) of the tensioned members is spaced from the longitudinal axis.

5 It is preferred that the tensioning arrangement comprises a means for adjusting the force applied to the electrical coupling. This allows the item of street furniture to be set-up appropriately by the installer. The means for adjusting the force applied to the electrical coupling may 10 comprise a means for adjusting the working length of a line. This is particularly effective if the tensioning arrangement comprises a line. Such a means for adjusting the working length of a line preferably facilitates the controllable and reversible adjustment of the working length. The working 15 length of a line is the length between the points at which it is attached. The working length may be different from the overall length of a line. The tensioning arrangement may comprise a means for fixing the working length of a line. This may comprise a line tie or crimp.

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It is preferred that the tensioning arrangement comprises a tension-adjusting line portion. Use of a line is an efficient and simple mechanism of adjusting the force applied to the electrical coupling, especially when used in 25 conjunction with a means for fixing the working length of a line.

One line may provide both the tension-adjusting line portion and at least one of the tensioned members. This facilitates 30 a simple tensioning arrangement that uses one line.

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Alternatively, the tension-adjusting line portion is connected to one or more of the tensioned members so that adjustment of the tension in the tension-adjusting line portion also adjusts the tension in at least one of 5 (preferably in a plurality of and more preferably in each of) the tensioned members. The tension-adjusting line portion may be connected to one or more of the tensioned members via an intermediate tension-coupler, such as a plate. The plate may be provided with apertures for' each of 10 one or more of the tensioned members and the tension-adjusting line portion.

One or more of the tensioned members may be provided by an elongate member, preferably by tensioned member lines. The 15 tensioned member lines may be connected to the tension-

adjusting line portion, for example, using an intermediate tension-coupler, so that adjustment of the tension in the tension-adjusting line portion also adjusts the tension in at least one of (preferably in a plurality of and more 20 preferably in each of) the tensioned members.

The term "line" herein refers to elongate structures, such as cables, ropes and wires, for transmitting force for the electrical coupling. The line may, for example, be made from 25 metallic materials, plastics or both. The line may be made from nylon. The line may be a monofilament or may comprise a plurality of filaments.

If the item of street furniture comprises a plurality of 30 tensioned members, the item of street furniture may be further provided with one or more guides for maintaining the mutual spacing of the tensioned members. Such a guide may be

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adapted to fit in a space defined within the body. The guide may comprise a plate provided with an aperture for each tensioned member to pass therethrough.

5 If the item of street furniture comprises three or more tensioned members, then the spacing between adjacent tensioned members may be the same for all adjacent tensioned members. It is preferred, however, that if the item of street furniture comprises three or more tensioned members, 10 then the spacing between adjacent tensioned members is not the same for all adjacent tensioned members.

It is preferred that at least one of the tensioned members is tethered or restrained at a point remote from the 15 electrical coupling. It is preferred that at least one of the tensioned members is tethered or restrained either above the upper impact limit, or between the lower impact limit and the upper impact limit.

20 The item of street furniture may be provided with a tethering member adapted to be fixed to the body. The tethering member provides a tethering or restraining point for one or more of the tensioned members. The tethering member may be in the form of a plate. The plate may be 25 provided with one or more apertures for passage of the tensioned members therethough.

It is preferred that the electrical coupling is laterally displaced from the body of the item of street furniture. It 30 is further preferred that, in use, the electrical coupling is, under normal operating conditions, located underground.

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Alternatively, the electrical coupling may be, under normal operating conditions, located above ground in a chamber remote from the body of the item of street furniture.

5 In accordance with a third aspect of the present invention, an item of street furniture comprising an electrical coupling and a body that, in a normal operating position, projects above a surface, the item of street furniture being, in use, provided with an electrical load,

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the electrical coupling comprising a first part which is, in use, associated with the electrical load and a second part which is, in use, associated with a power supply, the first and the second part being arranged so that the application 15 of a force above a threshold level causes movement between the first part and the second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in which the load is, in use, electrically isolated from a power supply

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wherein in the event that the body, or part thereof, is displaced by more than a threshold displacement from a normal operating position, then this displacement causes relative movement of the first and second parts of the 25 electrical coupling from the first position to the second position,

and when the body is in a normal operating position, a force is applied to the electrical coupling to aid the relative 30 movement of the first and second parts of the electrical coupling to the second position in the event that the body,

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or part thereof, is displaced from a normal operating position above a threshold displacement.

Those skilled in the art will realise that the power supply 5 and the electrical load are not necessarily part of the invention.

The item of street furniture of the third aspect of the present invention may comprise those features described 10 above with respect to the first and second aspects of the present invention. For example, the item of street furniture may be provided with a connecting member coupling the electrical coupling and the body such that displacement of the body, or part thereof, from a normal operating position 15 transmits a force via the connecting member to the electrical coupling. If the displacement of the body, or part thereof, from a normal operating position is above a threshold displacement, then a force is transmitted via the connecting member to the electrical coupling to cause 20 relative movement of the first and second parts of the electrical coupling from the first position to the second position.

The connecting member may comprise a line or the like. The 25 connecting member may comprise an electrical flex or cord for supplying electrical power to the electrical load. Alternatively, a line other than an electrical flex or cord for supplying electrical power to the electrical load may be used.

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It is preferred that the first part of the coupling is movable relative to the second part of the coupling from the first position to the second position.

5 The first part of the electrical coupling may be movable relative to the second part of the electrical coupling body from the first position to the second position by the application of a tensile force to the coupling. This is a convenient coupling arrangement. When such an arrangement is 10 used, it is preferred that when the body is in a normal operating position a tensile force is applied to the electrical coupling. This presents an item of street furniture with an efficient decoupling mechanism.

15 The item of street furniture may comprise a tensioning arrangement for applying a force to the coupling, the tensioning arrangement comprising one or more tensioned members which are, when the body is in a normal operating position, under tension, said tension exerting a force on 20 the electrical coupling, wherein the tensioning members are arranged so that in the event that the body, or part thereof, is displaced by more than a threshold displacement from a normal operating position, then this displacement causes an increase in tension in at least one of the 25 tensioned members sufficient to causes relative movement of the first and second parts of the electrical coupling from the first position to the second position.

The electrical coupling may be remote from the body.

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The phrase "first part which is, in use, associated with the electrical load" indicates that, in use, the first part of

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the electrical coupling is electrically connected to the electrical load. This means that, when the coupling is in the first position, electrical power may be transmitted via the first part of the coupling to the electrical load.

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The phrase "a second part which is, in use, associated with a power supply" indicates that, in use, the second part of the electrical coupling is electrically connected to the power supply. This means that, when the coupling is in the 10 first position, electrical power may be transmitted to the second part of the coupling from the power supply.

The item of street furniture may comprise an electrical load. The item of street furniture may comprise a power 15 supply.

In accordance with a fourth aspect of the present invention there is provided a kit for producing an item of street furniture in accordance with one or more of the first, 20 second and third aspects of the present invention, the kit comprising:

(a) an electrical coupling comprising a first part that is, in use, associated with an electrical load and a second part which is, in use, associated with a power supply, the first 25 and the second parts being arranged so that the application of a tensile force above a threshold level causes movement between the first part and the second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in 30 which the load is, in use, electrically isolated from a power supply, the coupling being adapted to be connectable to a line for applying a force to the coupling;

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(b) one or more elongate member for forming a tensioned member; and

(c) a means of tethering at least one of the elongate members for forming a tensioned member, the means of

5 tethering at least one of the elongate members being adapted to be secured to a body of an item of street furniture.

Such a kit may be used to adapt a conventional item of street furniture to an item of street furniture in 10 accordance with the present invention.

It is preferred that the one or more elongate member for forming a tensioned member is a line for forming a tensioned member. It is preferred that the kit comprises a plurality 15 of elongate members, each elongate member for forming a tensioned member.

The kit may further comprise a tension-adjusting line portion for adjusting the force applied to the electrical 20 coupling. Such a tension adjusting line portion may be required if, for example, there are more than one line for forming a tensioned member. The kit may comprise a tension-coupler for connecting the tension adjusting line portion to the lines for forming tensioned members.

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The kit may further comprise a body of an item of street furniture. This may be, for example, the shell of a lamppost .

30 The kit may further comprise an electrical load, such as a lamp. It is preferred that the electrical load is adapted to be mounted onto the body.

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The kit may further comprise a power supply for supplying electrical power to an electrical load.

5 It is preferred that, in use, the first part may be movable relative to the second part from the first position to the second position.

Those skilled in the art will realise that the use of the 10 tensioning arrangement described above may not be limited to the decoupling of electrical components in street furniture.

In accordance with a fifth aspect of the present invention, there is provided a device for disconnecting first and 15 second parts from one another, the first and second parts being arranged so that the application of a force above a threshold level causes movement between the first part and the second part from a first position in which the first and second parts are connected to one another to a second 20 position in which the first and second parts are disconnected from one another the device comprising a tensioning arrangement for applying a force to the first part, the tensioning arrangement 25 comprising one or more tensioned members which are, when in a normal operating conditions, under tension, said tension exerting a force on the first part, wherein the tensioning members are arranged so that in the event that one or more of tensioned members, or part thereof, is displaced by more 30 than a threshold displacement from a normal operating position, then this displacement causes an increase in tension in at least one of the tensioned members sufficient

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to causes relative movement of the first and second parts from the first position to the second position.

Those skilled in the art will realise that the device of the 5 fifth aspect of the invention does not necessarily include the first and second parts referred to above.

It is preferred that the first part may be movable relative to the second part from the first position to the second 10 position.

The device of the fifth aspect of the present invention may be used to decouple oil pipes, for example, should the pipeline be struck or damaged in some way. In this case, the 15 device is a device for disconnecting oil pipes, the first part being a first oil pipe or part thereof, and the second part being a second oil pipe or part thereof. In the first position, the first and second oil pipes (or parts thereof) may be in fluid communication with one another so that oil 20 may flow between the first and second oil pipes (or parts thereof).

The device would pull-apart two parts of the pipeline, thus possibly cutting the supply of oil through the pipeline. 25 Appropriate capping measures may be put in place to inhibit loss of significant quantities of oil from a separated pipe. For example, a spring loaded cap may be provided which falls into place over the end of a section of pipeline if the pipeline is parted.

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Furthermore, the device of the fifth aspect of the invention may be used to decouple electrical components in any

electrical system (not merely the electrical system described above in relation to street furniture). In this case, the device is a device for breaking electrical connections. The first part may be a first part of an electrical coupling and the second part may be a second part of an electrical coupling, which under normal operating conditions are in a coupled, electrically transmissive. The electrical coupling may have all of the features of the electrical coupling described with reference to the first, second, third and fourth aspects of the present invention. The application of a tension above the threshold level (as mentioned above) causes the first part of the coupling to move relative to the second part of the coupling into a non-electrically transmissive state (for example, by the first and second parts of the coupling being pulled apart). In the electrically non-transmissive state, two electrical components (such as a power supply and a load) are electrically isolated from one another.

For example, the device may be used to decouple mating electrical connectors (such as those mentioned above in relation to the first aspect of the present invention) to break the supply of electricity between a power supply and any electrical components that were previously connected to the power supply.

Several embodiments of the present invention will now be described by way of example only with reference to the following drawings of which:

Figure 1 is a schematic cross-section through a known lamppost;

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Figure 2a is a cut-away view of the lower portion of an item of street furniture (in this case, a lamp-post) in accordance with the present invention;

Figure 2b is a plan view of a portion of the lamp-post of 5 Figure 2a showing the arrangement of tensioning members;

Figure 3a shows a schematic view of a toppled item of street furniture;

Figure 3b shows a schematic view of a displaced item of street furniture;

10 Figure 3c shows a schematic view of an item of street furniture deformed about the impact zone;

Figure 4 shows a detail of a connection between lines forming tensioning members and a tension-adjusting line portion;

15 Figure 5 shows a detail of an alternative connection between lines forming tensioning members and a tension-adjusting line portion;

Figure 6 shows a cut-away view of a further embodiment of an item of street furniture in accordance with the present

20 invention and

Figure 7 shows a cut-away view of a portion of a further embodiment of an item of street furniture in accordance with the present invention.

25 A known item of street furniture (in this case, a lamp-post) is shown in Figure 1. The lamp post is provided with a body, P, and a lamp, L, located atop the body P. The lamp-post is provided with an electrical coupling 1 comprising male M and female F parts. In normal operation, the male M and female F

30 parts are mated together to form an electrical connection between the lamp L and a power supply V. When the lamp-post is struck by a vehicle, the body P is either displaced from

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its normal operating position, toppled or deformed. This movement cause the male M and females F parts of the electrical coupling to be separated, thus cutting the power supply to the lamp L. There are no live bare wares nor are 5 there any live protruding electrical parts. However, the female F part of the electrical coupling is located above ground at the scene of the accident and is electrically live.

10 An embodiment of an item of street furniture in accordance with the first, second and third aspects of the present invention will now be described with reference to Figures 2a and 2b. Figure 2A shows the lower portion of a lamp-post indicated generally by reference numeral 11 comprising an 15 electrical load (in the form of a lamp, not shown), an electrical coupling 108 and a body P that, in a normal operating position, projects above a surface S. The electrical coupling 108 comprises a first part 109 associated with the electrical load and a second part 110 20 which is, in use, associated with a power supply 107. In a normal operating position, the first part 109 (which has male electrical connectors) and second part 110 (which has female electrical connectors) are mated together to form an electrical connection between the lamp and the power supply 25 107. The electrical coupling 108 is an abrupt release coupling; the first part 109 may be pulled away from the second 110 part by the application of a tensile force above a threshold level. Once the first and second parts have been parted, the lamp is electrically isolated from the power 30 supply 107.

26

The lamp-post 11 is arranged such that displacement of the body P, or part thereof, from a normal operating position above a threshold displacement causes parting of the first 109 and second 110 parts of the electrical coupling. The 5 lamp-post body P comprises a standard 145mm diameter aluminium post.

In the present invention, when the body P is in a normal operating position (as is shown in Figure 2a), a tensile 10 force is applied to the electrical coupling 108. The tensile force is applied by a tensioning arrangement now described. Three tensioned members 102a, b, c are provided by three tensioned member lines 122a, b, c. These lines are 3mm diameter stainless steel cables. The ends of the tensioned 15 member lines 122a, b, c extend through apertures (not shown) provided in a fixing plate 101a which is attached to the interior of the hollow body P. A nut and bolt arrangement 132a, b, c is attached to each of the tensioned member line 122a, b, c to tether each of the tensioned member line 122a, 20 b, c.

The tensioned member lines 122a, b, c pass through apertures (not shown) in guide plate 101b and are brought together at link point 113 to link to a tension-adjusting line 103. It 25 should be noted that the link point 113 of Figure 2a is merely schematic, and a more detailed description of the connection of the tensioned member lines and the tension-adjusting line is described below with reference to Figures 4 and 5. Referring once more to Figure 2a, the tension 30 adjusting line 103 extends from link point 113 through loop 114 attached to first part 109 of the electrical coupling 108. A loop 104 is formed in the tension adjusting line,

27

with a cable retainer or crimp 105 being used to lock the loop portion 104 in place so that the working length of the tension adjusting line may be kept constant.

5 The tension-adjusting line 103 is in tension, as are the tensioned members 102a, b, c. Tension is therefore applied to the first part of 109 of the electrical coupling 108. The tension in the tension-adjusting line 103 and the tensioned members may be altered by altering the working length of the 10 tension-adjusting line 103. To do this, the crimp 105 (a Gripple rope grip, Gripple Ltd., Sheffield, England) is released or loosened and loop portion 104 lengthened or shortened by playing line through the loop 114 attached to the first part 109 of the electrical coupling 108. A shorter 15 working length of tension-adjusting line 103 will increase tension and a longer working length will decrease tension. Once the correct tension has been achieved the crimp 105 is pressed over the loop 104 and main line of the tension adjusting line so that the loop 104 and main line are 20 secured to one another. Those skilled in the art will realise that if the tension in the tension-adjusting line and the tensioned members is too high, then the first part 109 of the electrical coupling 108 will be parted from the second part without any vehicular impact. The second part 25 110 of the electrical coupling 108 is attached to the housing of the power supply 107.

Various arrangements may be used to link the tensioned member lines 122a, b, c to the tension-adjusting line 103, 30 and two of these arrangements are shown in detail in Figures 4 and 5. Figure 4 shows an arrangement whereby the ends of the tensioned member lines 122a, b, c are formed into loops

28

142a, b, c, each of which is supported by a metallic horseshoe or teardrop-shaped brace 152a, b, c. Similarly, the end of the tension-adjusting line 103 is formed into a loop 143 which is supported by a brace 153. The loops 143, 5 142a, b, c are fed onto a U-shaped member 154 having a lockable bar 155.

An alternative arrangement is shown in Figure 5. The end of each tensioned member line 122a, b, c is fed through an 10 aperture (not shown) in a tension-coupler 161, each end of the line 122a, b, c being adapted so as to inhibit passage of the end through the aperture formed in the tension-coupler 161. The tension coupler is in the form of a plate. The end of the tension-adjusting line 103 is also fed 15 through an aperture (not shown) in the tension-coupler, and the end adapted to inhibit passage of the end through the aperture formed in the tension-coupler. This arrangement, whilst somewhat time-consuming to assemble has proved to be an effective arrangement.

20

The body P has an impact zone shown as reference numeral 111, this being the portion of the body that is likely to be struck by a vehicle. The impact zone is bounded at the lower end by the lower impact limit, this being the lowest part of 25 the body likely to be struck during a reasonable vehicular impact and at the upper end by the upper impact limit, this being the highest part of the body likely to be struck during a reasonable vehicular impact. The tensioned members 102a, b, c are about 1.5mm long and extend along the entire 30 length of the impact zone 111. This is beneficial in producing a response from the apparatus.

29

The tensioned members are evenly spaced through the length of the impact zone. Figure 2b shows a cross-sectional view in the direction of arrows FF, and shows the spacing of the tensioned members. The apertures provided in the guide plate 5 101b correspond to the apertures provided in fixing plate

101a so that the tensioned members are evenly spaced through the length of the impact zone.

Metallic conduits (not shown) are provided around each 10 tensioned member between the guide plate 101b and the fixing plate 101a. These do not inhibit operation of the apparatus, but protect the tensioned members from unwanted chafing.

The power supply 107 and electrical coupling 108 are located 15 in a chamber 106 formed by a casing set into the ground. A conduit 112 extends from the body P to the chamber 106. The conduit in the present case is a 500mm length of plastics pipe of 60mm diameter.

20 For the purpose of testing, the lamp-post 11 was provided with a standard base plate. The lamp-post was set in 235mm depth concrete. 370mm depth of sand was applied to the previous ground level in order to provide a substrate into which the chamber 106 could be readily accommodated. There 25 was a total depth of sand of about 600mm on top of the concrete. The conduit was placed 280mm below the new ground level formed by the addition of the sand, and the chamber 106 was about 500mm deep. Sand was used in the present case because -it was convenient for the test installation of the 30 conduit and chamber. The fitting conditions mentioned above are merely provided as an example. Those skilled in the art

30

will realise that the lamp-post would be fitted according to local foundation conditions.

Operation of the item of street furniture in the event of 5 vehicular impact will now be described with reference to Figures 2a, 2b, 3a, 3b and 3c. When a vehicle strikes the impact zone 111 several forms of damage may occur to the post; the body of the post may be toppled, the body may be displaced from its mountings or the body may be deformed 10 around the impact zone. Referring to Figures 2a, 2b and 3a, in the event that the body P is toppled, the tension in at least one of the lines 122a, b, c increases above the threshold needed to pull the first part of the electrical coupling away from the second part. Referring to Figures 2a, 15 2b and 3b, in the event that the body is displaced from its mountings, the tension in at least one of the lines 122a, b, c increases above the threshold needed to pull the first part of the electrical coupling away from the second part. Referring to Figures 2a, 2b and 3c, in the event that the 20 body is deformed around the impact zone, the tension in at least one of the lines 122a, b, c increases above the threshold needed to pull the first part of the electrical coupling away from the second part.

25 Those skilled in the art will realise that the tensioned members 102a, b, c are so called because they are under tension when the body is in a normal operating position and until the first 109 and second 110 parts of the electrical coupling 108 are parted. Once the two parts of the 30 electrical coupling are parted, then there is no tension in the so-called tensioned members.

31

The electrical coupling 108 used in the item of furniture described with reference to Figures 2a and 2b is a proprietary coupling that requires a force above a predetermined level to decouple the two mating parts of the 5 plug. Commercially-available electrical couplings may be used in the item of street furniture of the present invention. Examples of such commercially-available couplings are the coupling used in the Dot Plug system (INGALEPS, Queensland 4106, Australia or [MG]2, Inc., Birmingham, 10 Alabama 35216, USA), the FTP-3/MTP-3 coupling (one of many supplied by Duraline, Islandia, NY 11749, USA) and those supplied by Sure Seal Connections, Philadelphia, PA 19116, USA (such as the coupling formed by Part Nos. 120-1869-000 and 120-1870-000). The use of such couplings is described in 15 US2004/0037084 and US5335160.

The item of street furniture described with reference to Figures 2 to 5 comprises a two-part electrical coupling whose two parts may be parted by the application of tension. 20 It is anticipated that the tensioning arrangement may be used with different electrical couplings, for example, those to which compressive forces are applied to move the first and second parts of the electrical coupling into a second (non-connective) position. Referring to Figure 7, this may 25 be achieved, for example, by passing the tension adjusting line 103 through an aperture in an electrical coupling 208, to be secured so that tension applied by the tension adjusting line 103 generates a compressive force on the electrical coupling 208.

30 Figures 2a and 2b show an item of street furniture using a tensioning arrangement that facilitates the remote location

32

of the electrical coupling relative to the body. It is entirely possible of course for the electrical coupling to be located remotely from the body without using a tensioning arrangement. Figure 6 shows how this may be achieved; an 5 electrical flex or cord 401 is attached to the first part 109 of the electrical coupling 108. The electrical coupling is remote from the body P. A friction reducing line guide 402 is provided to reduce damage to the electrical flex or cord 401 in the event of a vehicular impact. The electrical 10 flex or cord 401 is not in tension during normal operating conditions. On vehicular impact, the movement of the body causes the first part 109 of the electrical coupling to be parted from the second part 110, thus cutting the electrical supply to the lamp (not shown).

15

Whilst the examples above relate to lamp-posts, the teaching of those examples may be readily applied to other items of street furniture, such as road signs, bus stops, bus shelters, illuminated bollards, phone boxes or telephone 20 booths, traffic lights, traffic signals, runway approach lighting standards and runway beacons.

25

J

Claims

33 Claims

1. An item of street furniture comprising an electrical coupling and a body that, in a normal operating position,

5 projects above a surface, the item of street furniture being, in use, provided with an electrical load,

the electrical coupling comprising a first part which is, in use, associated with the electrical load and a second part 10 which is, in use, associated with a power supply, the first and second parts being arranged so that the application of a force above a threshold level causes movement between the first part and the second part from a first position in which the load is, in use, in electrical communication with 15 a power supply to a second position in which the load is, in use, electrically isolated from a power supply wherein in the event that the body, or part thereof, is displaced by more than a threshold displacement from a 20 normal operating position then this displacement causes relative movement of the first and second parts of the electrical coupling from the first position to the second position and wherein the electrical coupling is remote from the body.

25

2. An item of street furniture according to claim 1 provided with a connecting member coupling the electrical coupling and the body such that displacement of the body, or part thereof, from a normal operating position transmits a force

30 via the connecting member to the electrical coupling.

34

3. An item of street furniture according to claim 2 wherein the connecting member comprises a line.

A. An item of street furniture according to any preceding 5 claim wherein a portion of the connecting member extends through a cavity formed in a portion of the body having a longitudinal axis, said portion of the connecting member being spaced from the longitudinal axis.

10 5. An item of street furniture according to any preceding claim comprising a tensioning arrangement for applying a force to the coupling, the tensioning arrangement comprising one or more tensioned members which are, when the body is in a normal operating position, under tension, said tension 15 exerting a force on the electrical coupling, wherein the tensioning members are arranged so that in the event that the body, or part thereof, is displaced by more than a threshold displacement from a normal operating position,

then this displacement causes an increase in tension in at 20 least one of the tensioned members sufficient to causes relative movement of the first and second parts of the electrical coupling from the first position to the second position.

25 6. An item of street furniture according to claim 5 wherein when the body is in a normal operating position a tensile force is applied to the electrical coupling.

7. An item of street furniture comprising an electrical 30 coupling and a body that, in a normal operating position, projects above a surface, the item of street furniture being, in use, provided with an electrical load,

35

the electrical coupling comprising a first part which is, in use, associated with the electrical load and a second part which is, in use, associated with a power supply, the first 5 and second parts being arranged so that the application of a force above a threshold level causes movement between the first part and the second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in which the load is, in 10 use, electrically isolated from a power supply the item of street furniture further comprising a tensioning arrangement for applying a force to the coupling, the tensioning arrangement comprising one or more tensioned 15 members which are, when the body is in a normal operating position, under tension, said tension exerting a force on the electrical coupling, wherein the tensioning members are arranged so that in the event that the body, or part thereof, is displaced by more than a threshold displacement 20 from a normal operating position, then this displacement causes an increase in tension in at least one of the tensioned members sufficient to causes relative movement of the first and second parts of the electrical coupling from the first position to the second position.

25

8. An item of street furniture according to any one of claims 5 to 7 wherein one of the tensioned members comprises an electrical flex or cord connected to the first part of the coupling.

9. An item of street furniture according to any one of claims 5 to 8 comprising a plurality of tensioned members.

36

10. An item of furniture according to any of claims 5 to 9, wherein the body has an impact zone, the impact zone being a portion of the body between a lower impact limit defined as

5 the lowest part of the body that may reasonably be struck by a ground-travelling vehicle when the body is in a normal operating position and an upper impact limit defined as the highest part of the body that may reasonably be struck by a ground-travelling vehicle when the body is in a normal 10 operating position, and at least one of the tensioned members extends into the impact zone.

11. An item of street furniture according to claim 10 wherein at least one of the tensioned members extends from

15 the lower impact limit to the upper impact limit.

12. An item of street furniture according to claim 10 or claim 11 wherein the lower impact limit is from 0 to 50cm above the ground and the upper impact limit is from lm to 2m

20 above the ground.

13. An item of street furniture according to any one of claims 5 to 12 wherein the at least one tensioned members is associated with a portion of the body having a longitudinal

25 axis and at least one of the tensioned members is spaced from the longitudinal axis.

14. An item of street furniture according to any one of claims 5 to 13 wherein the tensioning arrangement comprises

30 a means for adjusting the force applied to the electrical coupling.

37

15. An item of street furniture according to claim 14 wherein the means for adjusting the force applied to the electrical coupling comprises a means for adjusting the working length of a line.

5

16. An item of street furniture according to any one of claims 5 to 15 wherein the tensioning arrangement comprises a means for fixing the working length of a line.

10 17. An item of street furniture according to any one of claims 5 to 16 wherein the tensioning arrangement comprises a tension-adjusting line portion.

18. An item of street furniture according to claim 17

15 wherein one line provides both the tension-adjusting line portion and at least one of the tensioned members.

19. An item of street furniture according to claim 17 wherein the tension-adjusting line portion is connected to

20 one or more of the tensioned members so that adjustment of the tension in the tension-adjusting line portion also adjusts the tension in at least one of the tensioned members.

25 20. An item of street furniture according to claim 19

wherein the tension-adjusting line portion is connected to each of the tensioned members so that adjustment of the tension in the tension-adjusting line portion also adjusts the tension in each of the tensioned members.

30

21. An item of street furniture according to claim 19 or claim 20 wherein the tension-adjusting line portion is

t

38

connected to one or more of the tensioned members via an intermediate tension-coupler.

22. An item of street furniture according to any one of

5 claims 5 to 21 wherein one or more of the tensioned members is provided by tensioned member lines.

23. An item of street furniture according to claim 9 and any one of claims 10 to 21 when dependent on claim 9 comprising

10 a one or more guides for maintaining the mutual spacing of the tensioned members.

24. An item of street furniture according to any one of claims 5 to 23 comprising three or more tensioned members,

15 wherein the spacing between adjacent tensioned members is not the same for all adjacent tensioned members.

25. An item of street furniture according to any one of claims 5 to 24 wherein at least one of the tensioned members

20 is tethered or restrained at a point remote from the electrical coupling.

26. An item of street furniture according to claim 25 wherein at least one of the tensioned members is tethered or

25 restrained either above the upper impact limit, or between the lower impact limit and the upper impact limit.

27. An item of street furniture according to claim 25 or claim 26 comprising a tethering member adapted to be fixed

30 to the body.

c

39

28. An item of street furniture according to any preceding claim wherein under normal operating conditions the electrical coupling is located at a position laterally displaced from the body of the item of street furniture.

5

29. An item of street furniture according to any preceding claim wherein the electrical coupling is, under normal operating conditions, located underground.

10 30. An item of street furniture according to any preceding claim wherein the first part of the electrical coupling is movable relative to the second part of the electrical coupling from the first position to the second position.

15 31. An item of street furniture comprising an electrical coupling and a body that, in a normal operating position, projects above a surface, the item of street furniture being, in use, provided with an electrical load,

20 the electrical coupling comprising a first part which is, m use, associated with the electrical load and a second part which is, in use, associated with a power supply, the first and second parts being arranged so that the application of a force above a threshold level causes movement between the

25 first part and the second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in which the load is, in use, electrically isolated from a power supply

30 wherein in the event that the body, or part thereof, is displaced by more than a threshold displacement from a normal operating position, then this displacement causes

J

40

relative movement of the first and second parts of the electrical coupling from the first position to the second position,

5 and when the body is in a normal operating position, a force is applied to the electrical coupling to aid the relative movement of the first and second parts of the electrical coupling to the second position in the event that the body, or part thereof, is displaced from a normal operating 10 position above a threshold displacement.

32. An item of street furniture according to any one preceding claim comprising an electrical load.

15 33. A kit for producing an item of street furniture in accordance with any preceding claim, the kit comprising:

(a) an electrical coupling comprising a first part that is, in use, associated with an electrical load and a second part which is, in use, associated with a power supply, the first

20 and second parts being arranged so that the application of a tensile force above a threshold level causes movement between the first part and the second part from a first position in which the load is, in use, in electrical communication with a power supply to a second position in 25 which the load is, in use, electrically isolated from a power supply, the coupling being adapted to be connectable to a line for applying a force to the coupling;

(b) one or more elongate member for forming a tensioned member; and

30 (c) a means of tethering at least one of the elongate members for forming a tensioned member, the means of

41

tethering at least one of the elongate members being adapted to be secured to a body of an item of street furniture.

34. A kit according to claim 33 comprising a tension-adjusting line portion for adjusting 'the force applied to the electrical coupling.

35. A kit according to claim 34 comprising a tension-coupler for connecting the tension adjusting line portion to the one or more elongate members for forming tensioned members.