Abstract:
A method of installing a joint into a light pole is described. The method includes the steps of supporting the light pole during cutting, then lowering a free portion of the lightpole about a hinge. The hinge is configured such that when a free portion of the light pole is lowered, wiring internal of the light pole is not significantly stretched.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the ‘retro-fitting’ of joints such as hinged joints or pivoting joints into poles, particularly light poles. 
       BACKGROUND TO THE INVENTION 
       [0002]    The Swivelpole™ is described in the International Patent Application published as WO0125687. This product consists of a light pole which has a swivelling joint along its length. The swivelling joint allows the light pole to be readily and safely raised or lowered in order for maintenance to be performed on a light or lamp. 
         [0003]    While light poles incorporating the Swivelpole™ joint have proved highly useful, with significant cost savings and safety improvements for light maintenance, it has not always been economically viable for existing light poles to be removed and replaced by swivelling light poles. 
         [0004]    Rather than the removal and replacement of existing light poles by Swivelpoles™, it has been possible to insert a swivelling joint into existing light poles. Often, such an operation has proved to be awkward, time consuming, and expensive. For example, extensive scaffolding may be required in order for a single joint to be fitted. 
         [0005]    It is considered desirable to provide a tool which allows significant change to an elevated light, such as the insertion of a swivel joint without the need for extensive scaffolding. 
         [0006]    The internal wiring of light poles has led to further problems in the retro-fitting of swivelling joints. Although means have been developed to support and hold an upper portion of a light pole when a cut is made into it, the lowering of these upper portions has frequently resulted in the stretching of and damage to internal wiring. 
         [0007]    It is also considered desirable to provide a method of inserting a swivelling joint without damaging the internal wiring. 
         [0008]    The present invention has been created in light of these desires. 
       SUMMARY OF THE INVENTION 
       [0009]    According to one aspect of the present invention there is provided a supporting structure for use in modifying a pole, the pole having a longitudinal axis and a characteristic thickness, 
         [0000]    the supporting structure including:
       a first arm having a first locator, the first locator being arranged to releasably attach to the pole;   a second arm having a second locator, the second locator being arranged to releasably attach to the pole;   a further arm connecting the first arm and the second arm, the first arm including a first portion and a second portion connected at a hinge, the hinge having a hinge axis about which the first portion can rotate relative to the second portion;   the hinge axis being perpendicular to the longitudinal axis of the pole when the first and second locators are attached to the pole;   the hinge axis being spaced from the longitudinal axis of the pole by a distance no greater than the characteristic thickness of the pole;   whereby rotation of the first portion relative to the second portion about the hinge causes the second arm to move between a first position in which the first and second locators are aligned, and a second position in which the first and second locators are not aligned.       
 
         [0016]    According to a second aspect of the present invention there is provided a supporting structure for use in modifying a pole, the pole having a longitudinal axis, 
         [0000]    the supporting structure including:
       a first arm having a first locator, the first locator being arranged to releasably attach to the pole;   a second arm having a second locator, the second locator being arranged to releasably attach to the pole;   a further arm connecting the first arm and the second arm, the first arm including a first portion and a second portion connected at a hinge, the hinge having a hinge axis about which the first portion can rotate relative to the second portion;   the first arm, the second arm and the hinge axis all being parallel to each other;   whereby rotation of the first portion relative to the second portion about the hinge causes the second arm to move between a first position in which the first and second locators are aligned, and a second position in which the first and second locators are not aligned.       
 
         [0022]    Preferably, the first arm, the second arm, and the hinge axis are all perpendicular to the longitudinal axis of the pole when the first and second locators are attached to the pole and the second arm is in the first position. 
         [0023]    According to a third aspect of the present invention there is provided a method of preparing a pole for installation of a joint, the pole having a longitudinal axis, the method including the steps of:
       attaching a supporting structure to the pole, the supporting structure attaching to the pole at two longitudinally separated locations;   cutting the pole at a joint location between the longitudinally separated locations, thereby creating a fixed portion of the pole and a free portion of the pole, the free portion of the pole being held into position relative to the fixed portion of the pole by the supporting structure; and   rotating the free portion of the pole relative to the fixed portion of the pole about a hinge of the supporting structure, the hinge having a hinge axis within a characteristic thickness of the pole from the longitudinal axis.       
 
         [0027]    According to a fourth aspect of the present invention there is provided a method of preparing a pole for installation of a joint, the method including the steps of:
       attaching a supporting structure to the pole, the supporting structure attaching to the pole at two longitudinally separated locations;   cutting the pole at a joint location between the longitudinally separated locations, thereby creating a fixed portion of the pole and a free portion of the pole, the free portion of the pole being held into position relative to the fixed portion of the pole by the supporting structure;   attaching a hinged support about the joint location, with the hinged support attaching to the fixed portion of the pole and the free portion of the pole; removing the supporting structure; and   rotating the free portion of the pole relative to the fixed portion of the pole about a hinge of the hinged support.       
 
         [0032]    The above methods may include the further step of removing wiring from the free portion of the pole. 
         [0033]    According to a fifth aspect of the present invention there is provided a method of installing a joint in a pole, the method including the steps of:
       attaching a supporting structure to the pole, the supporting structure attaching to the pole at two longitudinally separated locations;   cutting the pole at a joint location between the longitudinally separated locations, thereby creating a fixed portion of the pole and a free portion of the pole, the free portion of the pole being held into position relative to the fixed portion of the pole by the supporting structure;   attaching a hinged support to the pole about the joint location, with the hinged support attaching to the fixed portion of the pole and the free portion of the pole;   removing the supporting structure;   rotating the free portion of the pole relative to the fixed portion of the pole about a hinge of the hinged support;   removing wiring from the free portion of the pole;   removing the free portion of the pole and the hinged support; and   attaching a joint to the fixed portion of the pole at the joint location.       
 
         [0042]    The pole is preferably a light pole, and most preferably a light pole in excess of 2 m in height. 
         [0043]    The hinged support preferably comprises a first member and a second member, each of the first member and the second member having attachment portions for attaching to the pole, the first member and the second member being connected such that the first member can rotate relative to the second member about a hinge axis. 
         [0044]    The hinge axis is preferably perpendicular to a longitudinal axis of the pole. 
         [0045]    The pole has a characteristic thickness, which in the case of a cylindrical pole is the diameter of the pole. The arrangement is such that when the hinged support is attached to the pole, the hinge axis is within a characteristic thickness of the longitudinal axis of the pole. It is preferred that the hinge axis is spaced from the longitudinal axis of the pole at a distance of about half the characteristic thickness. In the case of a cylindrical pole, therefore, the hinge axis is spaced from the longitudinal axis of the pole by about the radius of the pole; that is, the hinge axis is close to tangential to the pole. 
         [0046]    In a most preferred embodiment the hinge axis is tangential to the pole. 
         [0047]    The first member and the second member of the hinged support may each include two connection portions, laterally spaced such that when the hinged support is attached to the pole the first connection portions of the first and second members may be located on one side of the pole, and the second connection portions of the first and second members may be located on an opposite side of the pole. 
         [0048]    The first connection portion of the first member may be connected to the first connection portion of the second member by an axial connecting member such as a bolt. The second connection portion of the first member may be connected to the second connection portion of the second member by an axial connecting member such as a bolt. In this arrangement the two axial connecting members are both located along the hinge axis. 
         [0049]    The first connection portion of the first member and the first connection portion of the second member may both include subsidiary apertures. The arrangement may be such that a first aperture of the first member may be aligned with a first aperture of the second member when the hinged support is in a first configuration; namely, when the first member and the second member are aligned such that, in use, the fixed portion of the pole and the free portion of the pole may be aligned. The first aperture of the first member may be aligned with a second aperture of the second member when the hinged support is in a second configuration; namely, when the second member has been rotated relative to the first member such that, in use, the fixed portion of the pole and the free portion of the pole are perpendicular. 
         [0050]    The methods above may include the step of locking the hinged support in its first configuration before removal to the attachment portion. They may also include the step of locking the hinged support in its second configuration following rotation of the free portion of the pole. The locking of the hinged support in a configuration may be achieved by the passing of a pin through the first aperture of the first member and an aligned aperture of the second member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0051]    It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings: 
           [0052]      FIGS. 1 to 10  are sequential perspectives of a light pole into which a joint is to be installed using at least one method of the present invention; 
           [0053]      FIG. 11  is a perspective of a supporting structure used in the method of  FIGS. 1 to 10 ; 
           [0054]      FIG. 12  is a side view of a hinged support used in the method of  FIGS. 1 to 10 ; shown in a first configuration; 
           [0055]      FIG. 13  is a side view of the hinged support of  FIG. 12  shown in a second configuration; 
           [0056]      FIG. 14  is an exploded view of the hinged support of  FIG. 12 ; 
           [0057]      FIG. 15  is a perspective of a hinged supporting structure in accordance with some aspects of the present invention, shown in a first configuration; 
           [0058]      FIG. 16  is a perspective of the hinged supporting structure of  FIG. 15 , shown in a second configuration; 
           [0059]      FIG. 17  is a side view of a lower portion of the hinged supporting structure of  FIG. 15 ; 
           [0060]      FIG. 18  is an end view of the hinged supporting structure of  FIG. 15 ; and 
           [0061]      FIG. 19  is a partially cut-away plan view of the hinged supporting structure of  FIG. 15 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0062]    Referring first to  FIGS. 1 to 14 ,  FIGS. 1 to 10  show a method of installing a joint  12 , such as a Swivelpole™ joint, into a light pole  10 . The method employs two particular pieces of equipment, a supporting structure  110  and a hinged support  210 . These items, shown in  FIGS. 11 to 14 , will be described before the method of installing a joint is detailed. 
         [0063]    Referring to  FIG. 11 , there can be seen a supporting structure  110  comprising a first arm  112 , a second arm  114 , and a further arm having a first portion  116  and a second portion  118 . 
         [0064]    In the position shown in  FIG. 2  the first arm  112  and the second arm  114  are generally horizontal, and the first and second portions  116 ,  118  of the further arm are generally vertical. The first arm  112  is connected to the first portion  116  of the further arm, and the second arm  114  is connected to the second portion  118  of the further arm. In the embodiment shown the first arm  112  and first portion  116  of the further arm are formed from a single section of tubing including a 90° bend. Similarly, the second arm  114  and the second portion  118  of the further arm are also formed from a single section of tubing including a 90° bend. 
         [0065]    The first portion  116  of the further arm is connected to the second portion  118  of the further arm by means of a primary joint  120 . The primary joint  120  is a swivelling joint in accordance with U.S. Pat. No. 6,957,832, the contents of which are incorporated herein by reference. 
         [0066]    It will thus be appreciated that the second arm  114  is arranged to rotate relative to first arm  112  about an axis of rotation oriented at 45° to a longitudinal axis of the first portion  116  of the further arm. 
         [0067]    The primary joint  120  includes a positioning means using four clamping bolts  130 . The clamping bolts  130  combine with force distributing plates  131  to clamp the primary joint  120  at a desired orientation. Loosening of the clamping bolts  130  permits rotation of the second portion  118  of the further arm relative to the first portion  116  of the further arm, while tightening of the clamping bolts  130  restricts this rotation. 
         [0068]    The primary joint  120  further includes a securing pin  132 . At least two of the force distributing plates  131  include pin receiving apertures  134 , which align when the primary joint  120  is in the orientation shown in  FIG. 11 . In the first position shown in  FIG. 11 , the securing pin  132  can be located within the pin receiving apertures  134  in order to prevent relative rotation of the first and second portions  116 ,  118  of the further arm. The securing pin  132  thus acts as an additional safety mechanism for the supporting structure  110 . 
         [0069]    The supporting structure  110  also includes a secondary joint, not shown in  FIG. 11 . The secondary joint is located in the connection of the primary joint  120  to the first portion  116  of the further arm. This connection is by means of a sleeve connection, where a lower end of the primary joint  120  includes a hollow tubular section which locates about an upper end of the first portion  116  of the second arm. 
         [0070]    The arrangement is such that the primary joint  120 , and therefore the second arm  114 , are able to rotate about an axis of rotation determined by the first portion  116  of the further arm. In practice, this secondary joint allows rotation about a vertical axis, being one parallel with a light pole  10  to which the supporting structure  110  is connected. 
         [0071]    The secondary joint includes a pin. The first portion  116  of the further arm includes a number of circumferential apertures which are arranged to accept the pin of the secondary joint. Accordingly, the relative rotational position of the primary joint  120  and the first portion  116  of the further arm can be selected to correspond with one of the circumferential apertures. 
         [0072]    The first arm  112  and the second arm  114  are the same length, and both extend from inner ends connected to the further arm to outer ends remote from the further arm. 
         [0073]    Each of the outer ends of the first and second arms  112 ,  114  has a locator, or clamp  140 , mounted to it. 
         [0074]    The clamp  140  is formed with a connecting portion, which is tubular, and a gripping portion  144 . The connecting portion is sized so as to locate within the outer end of the first arm  112  or the second arm  114  in a telescoping manner. The connecting portion  142  includes bolt receiving apertures which are arranged to align with similar apertures on the first or second arms  112 ,  114 . Holding bolts  148  can then be passed through the apertures of the first or second arm  112 ,  114  and the bolt receiving apertures in order to hold the clamp  140  in position. 
         [0075]    In an alternative arrangement (not shown), the first and second arms  112 ,  114  can be formed with flanges at their respective outer ends, and the clamps  140  equipped with corresponding flanges. The clamps  140  can therefore be secured in position by use of a plurality of bolts arranged around a flanged connection. 
         [0076]    The gripping portion  144  includes a fixed arm  150 , a pivoting arm  152  and a restraining bolt  154  which extends from the fixed arm  150  and which is arranged to be received within a catching portion  156  of the pivoting arm  152 . The arrangement is such that when the clamp  140  is brought against a pole, the pivoting arm  152  can be closed around the pole such that the pole is gripped between the fixed arm  150  and the pivoting arm  152 . The restraining bolt  154  can then be tightened so that the clamp  140  closely grips the pole. 
         [0077]    Referring to  FIGS. 12 to 14 , there is shown a hinged support  210 . The hinged support  210  includes a first member  212  and a second member  214 . The first member  212  and the second member  214  are substantially mirror-images of each other. 
         [0078]    Each of the first member  212  and the second member  214  include an attachment portion  220 , a first side flange  222  and a second side flange  224 . The first and second side flanges  222 ,  224  each include a generally rectangular rear portion  226  and a generally triangular connection portion  228 . 
         [0079]    Each of the first and second flanges  222 ,  224  has an outer edge  230  and an inner edge  232 . The outer edge  230  is straight. The inner edge  232  has three sections: a rear section  234  which is parallel to and spaced from a rear section  236  of the outer edge  230 ; a middle section  238 , and a front section  240 . The rear section  234  of the inner edge  232  and the rear section  236  of the outer edge  230  define the longer edges of the generally rectangular rear portion  226 . The middle section  238  of the inner edge  232 , the front section  240  of the inner edge  232 , and a front section  242  of the outer edge  230  together define the generally triangular connection portion  228 . 
         [0080]    The connection portion  228  is in the general form of a right isosceles triangle, with the front section  242  of the outer edge  230  forming the hypotenuse. It will therefore be appreciated that both the middle section  238  and the front section  240  of the inner edge  232  are disposed at  45 ° to the rear section  234  of the inner edge  232 . 
         [0081]    Each attachment portion  220  acts as a web between the rear portion  226  of the first side flange  222  and the second side flange  224 , such that the rear of both the first member  212  and the second member is  214  is generally configured as a channel. 
         [0082]    Each attachment portion  220  includes a gripping portion  244  similar to the gripping portion  144  of the supporting structure  110 . The gripping portion  244  includes a fixed arm  250  which may be welded to the attachment portion  220 , a pivoting arm  252  and a restraining bolt  254  which extends from the fixed arm  250  and which is arranged to be received within a catching portion  256  of the pivoting arm  252 . The arrangement is such that when the gripping portion  244  is brought against the pole  10 , the pivoting arm  252  can be closed around the pole such that the pole is gripped between the fixed arm  250  and the pivoting arm  252 . The restraining bolt  254  can then be tightened so that the gripping portion  244  closely grips the pole. 
         [0083]    The triangular connection portions  228  each include three apertures: a first aperture  260 , a second aperture  262  and a hinge receiving aperture  264 . These apertures may be considered as a primary aperture, being the hinge receiving aperture  264 , and two subsidiary apertures being the first and second apertures  260 ,  262 . 
         [0084]    The three apertures are located close to the three points of the triangle forming the connection portion  228 . The hinge receiving aperture  264  is located near the right angle; that is, near the connection of the middle section  238  and the front section  240  of the inner edge  232 . In the first member  212 , the first aperture  260  is located at the front of the connection portion  228 ; that is, near the connection of the front section  240  of the inner edge  232  and the front section  242  of the outer edge  230 . The second aperture  262  is located at the rear of the connection portion  228 ; that is, near the connection of the middle section  238  of the inner edge  232  and the front section  242  of the outer edge  230 . In the second member  214 , the relative positions of the first and second apertures are exchanged. 
         [0085]    In order for the hinged support  210  to be formed, the first member  212  and the second member  214  are brought together such that the connection portions  228  are adjacent. In the example of the drawings, the arrangement is such that the connection portion  228  of the first side flange  222  of the first member  212  is inside the connection portion  228  of the first side flange  222  of the second member  214 , and the connection portion  228  of the second side flange  224  of the first member  212  is outside the connection portion  228  of the second side flange  224  of the second member  214 . 
         [0086]    In this configuration, it will be appreciated that the first apertures  260  of the first member  212  will be aligned with the first apertures  260  of the second member  214 ; the second apertures  262  of the first member  212  will be aligned with the second apertures  262  of the second member  214 ; and the hinge receiving apertures  264  of the first member  212  will be aligned with the hinge receiving apertures  264  of the second member  214 . 
         [0087]    The first member  212  is joined to the second member  214  by using two axial connection members being hinge bolts  270 : one passing through the hinge receiving apertures  264  of the first side flanges  222  of the first and second members  212 ,  214 ; and the other passing through the hinge receiving apertures  264  of the second side flanges  224  of the first and second members  212 ,  214 . It will be appreciated that the two hinge bolts  270  are located along a common axis, which defines the hinge axis of the hinged support  210 . It will also be appreciated that the hinge bolts  270  are spaced from each other by the width of the attachment portions  220 . 
         [0088]    The arrangement is such that when the hinged support  210  is in the configuration described, with respective first and second apertures  260 ,  262  of the first and second members  212 ,  214  aligned, and the hinged support  210  is mounted to the light pole  10  by means of the gripping portions  244 , then the hinge axis will be approximately tangential to the light pole  10 . 
         [0089]    It will be appreciated that the hinged support  210  can be moved between two configurations: a first configuration as shown in  FIG. 12  in which the first member  212  and the second member  214  are parallel, and a second configuration as shown in  FIG. 13  in which the first member  212  and the second member  214  are perpendicular. Movement between the configurations can be achieved by relative rotation of the first and second members  212 ,  214  about the hinge bolts  270 . 
         [0090]    When in the first configuration, the respective first and second apertures  260 ,  262  of the first and second members  212 ,  214  are aligned as described above. When in the second configuration, the first apertures  260  of the second member  214  become aligned with the second apertures  262  of the first member  212 , as can be seen in  FIG. 13 . 
         [0091]    The method of installing the joint  12  into the light pole  10  is shown in  FIGS. 1 to 10 .  FIG. 1  shows the light pole  10  prior to installation of the joint  12 . 
         [0092]    The first action is to locate the desired position  14  for the joint  12 , along the light pole  10 . When this has been determined, the supporting structure  110  is attached to the light pole  10  by means of the clamps  140 . The arrangement is such that the first arm  112  is located above the desired position  14 , and the second arm  114  is located below the desired position  14 . The first and second portions  116 ,  118  of the further arm of the supporting structure  110  are substantially parallel to, and spaced from, the light pole  10 . 
         [0093]    The supporting structure  110  is locked into position about the light pole  10  by tightening of the restraining bolts  154 . This is shown in  FIG. 2 . 
         [0094]    Once the supporting structure  110  is locked into position, the light pole  10  can be cut at the position  14  by a suitable rotary cutter  15 . Care must be taken not to damage any wires passing internally of the light pole  10 . Once cutting is complete, the light pole is in two parts: a fixed portion  16  mounted to a base, and a free portion  20  including a light source  22 . The fixed portion  16  and the free portion  20  are separated at a cut  24 . 
         [0095]    At this stage of the installation, as shown in  FIG. 3 , the supporting structure  110  holds the free portion  20  relative to the fixed portion  16 , preventing relative movement. 
         [0096]    The hinged support  210  in its first configuration is now fixed to the light pole  10 , with the first member  212  being connected to the fixed portion  16  by use of its gripping portion  244 , and the second member  214  being connected to the free portion  20  by use of its gripping portion  244 . The hinged support  210  is positioned such that the hinge bolts  270  are aligned with the cut  24  in the light pole  10 . In the embodiment shown, the hinged support  210  is sized relative to the light pole  10  such that the hinge axis is tangential to the (circular) cut  24 . 
         [0097]    The hinged support  210  is locked into position about the light pole  10  by tightening of the restraining bolts  254 . In addition, the hinged support  210  is maintained in its first configuration by the insertion of a pin through the aligned first apertures  260 . This is shown in  FIG. 4 . 
         [0098]    Once the hinged support  210  has been secured into position, the supporting structure  110  can be safely removed. At this stage of the installation, as shown in  FIG. 5 , the hinged support  210  holds the free portion  20  relative to the fixed portion  16 , preventing relative movement. 
         [0099]    The hinged support  210  can now be carefully moved into its second configuration, thus rotating and hence lowering the free portion  20  of the light pole  10  relative to the fixed portion  16 . In order for this to achieved, the pin must be removed from the first apertures  260 . Once the hinged support is in its second configuration, the pin can be reinserted into the aligned first and second apertures  260 ,  262 . 
         [0100]    It will be appreciated that the free portion  20  of the light pole  10  is now disposed at  90 ° to the fixed portion  16 . This is shown in  FIG. 6 . 
         [0101]    It will also be appreciated that the free portion  20  and, importantly, any wiring  26  inside the free portion  20 , has been rotated about the hinge axis, tangential to the light pole  10 . This means that the radius of curvature of the wiring  26  is extremely small, and in consequence there is little or no stretching of the wiring  26 . 
         [0102]    Once the hinged support  210  has been secured in its second configuration by use of the pin, the undamaged wiring  26  can be safely disconnected from the light source  22 , and withdrawn from the free portion  20  of the light pole  10 . This is shown in  FIG. 7 . 
         [0103]    With no internal wiring now passing through the free portion  20 , the free portion  20  and the hinged support  210  can be safely removed, leaving only the fixed portion  16  from which the wiring  26  protrudes. This is shown in  FIG. 8 . The wiring  26  can be passed through the joint  12  as it attached around the cut end  24  of the fixed portion  16  of the light pole  10 , as shown in  FIG. 9 . 
         [0104]    Finally, a new free portion  30  including a new light source  32  can be located onto the joint  12 , as shown in  FIG. 10 . 
         [0105]    An alternative method and supporting structure is shown in  FIGS. 15 to 19 . 
         [0106]    Referring to  FIG. 15 , there can be seen a supporting structure  310  comprising a first arm  312 , a second arm  314 , and a further arm having a first portion  316  and a second portion  318 . 
         [0107]    In the position shown in  FIG. 15  the first arm  312  and the second arm  314  are generally horizontal, and the first and second portions  316 ,  318  of the further arm are generally vertical. The first arm  312  is connected to the first portion  316  of the further arm, and the second arm  314  is connected to the second portion  318  of the further arm. In the embodiment shown the first arm  312  and first portion  316  of the further arm are formed from a single section of tubing including a 90° bend. Similarly, the second arm  314  and the second portion  318  of the further arm are also formed from a single section of tubing including a 90° bend. 
         [0108]    The first portion  316  of the further arm is connected to the second portion  318  of the further arm by means of a hinged connection  320 . 
         [0109]    Each of the outer ends of the first and second arms  312 ,  314  has a locator, or clamp  340 , mounted to it. 
         [0110]    The operation of the clamp  340  can be seen in more details in  FIG. 19 , which shows the clamp from the first arm  312 . 
         [0111]    The clamp  340  includes an engaging portion  342  and an encircling portion  344 . The encircling portion  344  includes a curved fixed arm extension  350  which extends from the end of the first arm  312  about a curve arranged to pass about 90° around a pole  10 . The encircling portion  344  also includes a pivoting arm  352 , which is generally right angled and is arranged to pass around 180° of the pole  10 . The pivoting arm  352  is connected to the fixed arm extension  350  at a pivot  353 . 
         [0112]    A catch  354  is pivotally connected to the first arm  312  at a side opposed to the fixed arm extension  350 . The catch  354  has a hook  356  at an outer end thereof, arranged to engage with a hook  358  at an outer end of the pivoting arm  352 . The catch  354  is biased (for instance, by use of a spring) into a position where the hooks  354 ,  356  engage each other, thus causing the encircling portion  344  to pass around the pole  10 . 
         [0113]    The engaging portion  342  has a cradle  360  at an outer end thereof, extending from the first arm  312 . The cradle  360  is mounted to a shaft  362  which extends internally of the first arm  312 , and which includes a threaded connection to the first arm  312 . The shaft  362  extends through the first arm  312 , terminating in an outer extension  364  located at the first portion  316  of the further arm. 
         [0114]    The outer extension  364  is mounted to a driving wheel  366  located outside the first portion  316  of the further arm. The arrangement is such that turning of the driving wheel  366 , which may be manually operated, is translated via the threaded connection into axial movement of the shaft  362  and thus the cradle  360 . 
         [0115]    The clamp  340  can thus be secured to the pole  10  by firstly opening the catch  354 ; pivoting the pivoting arm  352  into an open position; locating the clamp  340  generally about the pole  10  and closing the pivoting arm  352 ; operating the catch  354  to engage the hook  358  and thus encircle the pole  10 ; and then operating the driving wheel  366  to urge the cradle  360  against the pole  10  until the pole  10  is rigidly clamped between the cradle  360  and the pivoting arm  344 . 
         [0116]    The first portion  316  of the further arm is joined to the second portion  318  of the further arm by an axial connection member being a hinge bolt  370 . The hinge bolt  370  is perpendicular to an elongate axis of the further arm, and parallel to the first arm  312  and the second arm  314 . The hinge bolt  370  is located along one side of the further arm, rather than passing through the elongate axis. The hinge bolt  370  defines a hinge axis of the supporting structure  310   
         [0117]    The arrangement is such that when the supporting structure  310  is mounted to the light pole  10  by means of the clamps  340 , then the hinge axis will be approximately tangential to the light pole  10 . 
         [0118]    It will be appreciated that the supporting structure  310  can be moved between two configurations: a first configuration as shown in  FIG. 15  in which the first member  312  and the second member  314  are parallel, and a second configuration as shown in  FIG. 16  in which the first member  312  and the second member  314  are perpendicular. Movement between the configurations can be achieved by relative rotation of the first and second members  312 ,  314  about the hinge bolt  370 . 
         [0119]    The first arm portion  316  has a first aperture (not shown) which is parallel to, and laterally spaced from the hinge bolt  370 . The second arm portion  318  has a corresponding first aperture, such that when the supporting structure  310  is in the first configuration then a pin  372  can be located within the aligned first apertures, securing the supporting structure  310  in the first configuration. 
         [0120]    The second arm portion  318  has further apertures, at locations  374  shown on  FIG. 18 . The locations  374  are such that the first apertures of the first arm portion aligns with further apertures of the second arm portion when the supporting structure  310  is in the second configuration, or indeed in an intermediate configuration. The pin  372  can thus be used to secure the supporting structure in a desired configuration. 
         [0121]    A method of installing the joint  12  into the light pole  10  using the supporting structure  310  will now be described. 
         [0122]    The first action is to locate the desired position  14  for the joint  12 , along the light pole  10 . When this has been determined, the supporting structure  310  is attached to the light pole  10  by means of the clamps  340 . The arrangement is such that the first arm  312  is located above the desired position  14 , and the second arm  314  is located below the desired position  14 . The first and second portions  316 ,  318  of the further arm of the supporting structure  310  are substantially parallel to, and spaced from, the light pole  10 . 
         [0123]    The supporting structure  310  is locked into position about the light pole  10  by tightening of cradles  342  using the driving wheels  366 . 
         [0124]    Once the supporting structure  310  is locked into position, the light pole  10  can be cut at the position  14  by a suitable rotary cutter  15 . Care must be taken not to damage any wires passing internally of the light pole  10 . Once cutting is complete, the light pole is in two parts: a fixed portion  16  mounted to a base, and a free portion  20  including a light source  22 . The fixed portion  16  and the free portion  20  are separated at a cut  24 . 
         [0125]    At this stage of the installation, the supporting structure  310  holds the free portion  20  relative to the fixed portion  16 , preventing relative movement. 
         [0126]    The supporting structure  310  can now be carefully moved into its second configuration, thus rotating and hence lowering the free portion  20  of the light pole  10  relative to the fixed portion  16 . In order for this to achieved, the pin  372  must be removed from the first apertures. Once the supporting structure  310  is in its second configuration, the pin can be reinserted into the aligned first and further apertures. 
         [0127]    It will be appreciated that the free portion  20  of the light pole  10  is now disposed at 90° to the fixed portion  16 . This is shown in  FIG. 16 . 
         [0128]    It will also be appreciated that the free portion  20  and, importantly, any wiring  26  inside the free portion  20 , has been rotated about the hinge axis  322 , tangential to the light pole  10 . This means that the radius of curvature of the wiring  26  is extremely small, and in consequence there is little or no stretching of the wiring  26 . 
         [0129]    Once the supporting structure  310  has been secured in its second configuration by use of the pin  372 , the undamaged wiring  26  can be safely disconnected from the light source  22 , and withdrawn from the free portion  20  of the light pole  10 . 
         [0130]    With no internal wiring now passing through the free portion  20 , the free portion  20  and the supporting structure  310  can be safely removed, leaving only the fixed portion  16  from which the wiring  26  protrudes. This is shown in  FIG. 8 . The wiring  26  can be passed through the joint  12  as it attached around the cut end  24  of the fixed portion  16  of the light pole  10 , as shown in  FIG. 9 . 
         [0131]    Finally, a new free portion  30  including a new light source  32  can be located onto the joint  12 , as shown in  FIG. 10 . 
         [0132]    Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. For instance, it will be apparent that the swivelling supporting structure  110  described herein could be readily replaced with a non-swivelling supporting structure, without effecting any change to the method of  FIGS. 1 to 14  described above.