Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
  • E04H12/18—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures movable or with movable sections, e.g. rotatable or telescopic
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
  • E04H12/18—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures movable or with movable sections, e.g. rotatable or telescopic
  • E04H12/182—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures movable or with movable sections, e.g. rotatable or telescopic telescopic

Definitions

• the present invention relates to a mast and more particularly to a mast which is intended in use to support a structure above a mast base section.
• Masts are widely used for supporting lighting apparatus above .the ground, such as, for example, at sports stadiums or the like.
• the height at which flood lighting apparatus can be held above the ground is of significant importance to the effective lighting of an area.
• Conventional flood lighting masts including the head frame on which the lighting equipment is mounted can be as tall as 40-50 metres or more. Accordingly the structural support required at the base of such masts is significant and conventional masts take the form of permanent structures which are erected and fixed in place until they are replaced or else dismantled for maintenance work.
• a mast for supporting equipment during use the mast being fixable in a generally upstanding orientation relative to a support surface and comprising: first and second elongate mast sections, the first and the second sections being oriented substantially coaxially; drive means for effecting linear movement of said second section relative to said first section such that the mast is actuable between a first condition in which the second section is retracted relative to said first section, and a second condition, in which the second section is extended; and, transmission means connected in the force path between the drive means and the second mast section and arranged to increase the magnitude of the displacement of the second mast section relative to the first mast section applied by the drive means.
• the mast comprises a third mast section, which may be elongate in shape and which .may be oriented substantially coaxially with said first section and moveable relative to the first section.
• the third section may also be linearly moveable relative to the second section.
• the mast may be telescopic.
• the mast according to the present invention may be extended and retracted between an at rest condition and an in-use condition or else between different operating heights. This can be is significant benefit since it allows the mast to be extended into a usage condition for required periods of time, without providing an eyesore when not in use.
• the present invention may also be particularly advantageous in that a mast may be permanently installed by fixation of the base section relative to a support surface, such as for example the ground.
• a support surface such as for example the ground.
• the size of conventional masts can push the boundaries of conventional crane lifting capabilities.
• the reduced length of the retracted mast according to the present invention may significantly simplify installation of the mast on site.
• an extending/retracting mast may allow a single mast design to be installed in a number of varying locations.
• the mast may be simply be extended to a greater or lesser extent during use to account for the varying requirements of different installation sites.
• different masts on the same site could be raised to different heights in use if required.
• the present invention may allow customisation of lighting on a single site in a manner which was not hitherto possible.
• the first section may comprise a base or pedestal section of the mast.
• a base or pedestal section may be provided such that any combination of the first and/or second sections may be moveable relative to the base.
• the base or pedestal section may be hollow and may house the drive means.
• a chain may be connected between one end of one mast section and an opposing end of another mast section.
• the chain may be connected at one end to one mast section and at an opposing end to another mast section.
• the chain may pass about a pulley wheel.
• a chain may be connected at one end to a first mast section and may pass over a pulley mounted on a second mast section and may be connected at its second end to a third mast section.
• the second mast section may be intermediate the first and third mast sections.
• Each of the mast sections may be generally tubular or sleeve-like in form such that each mast section may house a further mast section therein.
• the cross-sectional profile of the or each mast section may have one or more straight edges.
• Each mast section may have one or more faces which may be flat. Such an arrangement has been found to be beneficial in preventing rotation of the mast sections about the mast axis when compared to mast sections which are generally circular in cross-section.
• Any or each mast section may be for example rectangular, pentagonal, hexagonal or octagonal.
• One or more mast sections may have an opening for passage of the chain therethrough.
• a pulley may be mounted on the mast section adjacent the opening.
• One or more mast sections may have attachment formations on an outer wall thereof for attachment of the chain thereto.
• Figure 1 shows a rear view of a mast according to one embodiment of the present invention
• Figures 2A shows a longitudinal sectional view of a mast according to the present invention in a retracted condition
• Figures 3A shows a longitudinal sectional view of the mast of figure 2 in an extended condition
• Figure 5 shows an example of cable management apparatus for use in conjunction with one embodiment of the present invention.
• Lighting equipment (not shown) is typically mounted on arms 18 for use.
• a connector 20 by which the lighting equipment can be connected or disconnected from a power supply.
• Electrical cabling is provided within the mast 12 as be described in further detail below.
• the head frame is permanently attached to the mast upon manufacture and the cables are permanently attached to the relevant lighting apparatus.
• the present invention allows for attachment of the head frame 14 to be connected to the mast 12 on site.
• the plug/socket arrangement 20 on the lighting framework itself allows simple electrical connection and disconnection of the lighting apparatus as required. Power is supplied to lighting equipment mounted on arms 18 via the plug/socket arrangement 20.
• the mast 12 comprises a base section 22 and a plurality of elongate mast sections 24 depending therefrom.
• the plurality of mast sections 24 comprise a first 26, a second 28, a third 30 and a fourth 32 mast section.
• Each mast section takes the form of a substantially hollow tubular formation, with the first section having the greatest lateral or width dimension such that it can house the second, third and fourth mast sections therein.
• the fourth mast section 32 is mounted within the third mast section which is mounted within the second mast section, which is in turn mounted within the first mast section in a concentric arrangement.
• the first mast section 26 has at its lower end a circumferential mounting flange 33 which faces a similarly shaped mounting flange 34 on the base section 22. Bolts are passed through the opposing mounting flanges when they are in abutment so as to secure the base 22 and the first mast section in an end to end engagement.
• the base 22 may have an opening 36 in order to provide access to its hollow interior.
• the base section is fixed in an upstanding orientation to a support surface 38. It will be understood by the person skilled in the art that an additional support structure or foundation for the mast may be provided below the level of the support surface 38 and may be sunk below ground level.
• the fourth mast section 32 being the uppermost mast section when the mast is oriented as shown in figure 1 has a flange formation at its free end for attachment of the head frame 14 thereto.
• the spinal portion 16 of the head frame may have a corresponding opposing flange portion at its lower end.
• FIG 2 there are shown longitudinal sectional views of the mast 12 taken through its centreline 40.
• the base section 22 of the mast has been removed.
• the mast 12 is in a retracted condition such that each of the mast sections 28, 30 and 32 extend into the interior of the mast section 26. In this condition a minor portion of each of mast sections 28, 30 and 32 protrudes from an upper end of the section 26. A majority of the length of each of those sections is enclosed within section 26.
• the mounting flange formation 42 of the uppermost or fourth mast section 32 is shown in figure 2 and comprises an end plate of greater diameter than that of the tubular portion of mast section 32.
• the flange 42 has openings therein for bolting the head frame 14 thereto.
• the collar formations each comprise a pair of spaced circumferential lip or rim formations which depend outwardly from the tubular body of each mast section.
• the mast sections are not circular in cross section.
• the mast sections each have a plurality of substantially flat side walls and, in this embodiment, the mast sections are octagonal in cross section.
• the non-circular nature of the side walls helps to provide torsional stability of the mast about its centreline and resists twisting such as, for example, as a result of wind loading. It is envisaged that other polygonal cross-sectional profiles or else an elliptical section may provide suitable alternatives for this purpose.
• a drive means in the form of a hydraulic ram 46 is provided within the mast 12.
• the ram 46 is mounted in the interior space of the first mast section 26.
• the first mast section is rigidly attached to the base section and not moved during extension or retraction of the mast.
• the ram 46 comprises a piston 48 and cylinder 50 arrangement.
• the cylinder comprises an internal cavity 52, within which the piston 48 is seated. Fluid is applied under pressure to the internal cavity 52 to cause relative movement between the piston and cylinder.
• the ram 46 is anchored by a supporting rod formation 54 which passes into the base section 22.
• the head of the piston 48 is attached to the base and the cylinder 50 is moveable relative thereto in use. The head of the piston is thus attached to the rod formation 54.
• the cylinder 50 has connection formations in the form of opposing pins or lugs 56 which protrude outwardly of the cylinder body at its lowest end.
• the lugs 58 are received in correspondingly shaped openings 58 within an internal support member 60 of the second mast section 28.
• the lugs 58 and internal support member 60 are load bearing in that they allow transfer of force from the ram 46 to the second cylinder.
• the internal support member 60 comprises an inwardly extending cross member which depends from the wall of the second mast section.
• the support member may span between opposing side walls of the second mast section.
• the support member may comprise opposing plate formations, between which the ram is mounted.
• a pulley system is also provided for the transfer of force to the third and fourth mast sections during use.
• the pulley system allows the ram to indirectly actuate the third and fourth mast sections during operation as will be described in further detail below.
• the pulley system comprises a first linked metal chain 62 which is connected at one end to the upper end of the first mast section 26.
• the first chain 62 is connected to the collar 44 of the first mast section by a bolt fastener.
• the first chain passes from the first mast section over a pulley 64 mounted at an upper end of the second mast section and terminates at a fastening 66 on the wall of the third mast section 30.
• the fastening 66 is provided part way along the length of the third mast section and typically towards its lower end (i.e. spaced from the upper end of the adjacent mast section).
• the chain 62 is connected to the fastening 66 by a bolt (not shown).
• the first chain 62 provides a force path between the first and third mast sections which is actuable by movement of the second mast section.
• a second chain 68 is connected at one end to the upper end of the second mast section.
• the second chain 68 provides a force path between the second and fourth mast sections which is actuable by movement the third mast section.
• first 62 and a second chain 68 Whilst only a first 62 and a second chain 68 are described for simplicity, it will be appreciated that additional chain and pulley systems may be used in parallel with the first and second chains for additional strength.
• additional first chain 74 is provided on an opposing side of the mast in parallel with the first chain 62 which passes over an additional pulley mounted to the second mast section and having connections to the mast sections as described above.
• An additional second chain 76 and pulley system is also provided in parallel with the second chain 68 and mounted on the opposing side of the mast.
• Electrical cables 78 depend from the wall of the first mast section 26.
• the cable 78 passes beneath the lowermost ends of the moveable mast sections and is attached to the uppermost or fourth mast section.
• the cable may pass through an opening 80 in the end plate 42 of the fourth mast section for connection to the head frame 14 via the plug and socket arrangement 20 shown in figure 1.
• the mid section may be provided with a cable management structure to control the freedom of movement of the cable within the mast.
• the cable 78 may be connected to one or more power lines within the mast base or else may pass outside the mast through an opening in the wall thereof for connection to power lines outside of the mast.
• the mast is shown in its extended condition, wherein the length of the mast is substantially greater than that shown in figure 2.
• the mast is not a maximum extension.
• pressure is applied to the cylinder chamber 52 of the ram 46.
• the cylinder is forced away from piston 48 and the force exerted by the pressurised fluid in the chamber 52 is transmitted to the second mast section 28 via the lugs 56 and cross member 60.
• the second mast section 26 is actuated by the ram 46 and moves in unison therewith relative the first mast section.
• the first mast section provides a rigid sleeve, through which force from the drive means can be transmitted to the other moveable mast sections via the pulley system.
• a tension is applied to first chain 62 via pulley 64 which moves in unison with the second mast section 28.
• the first end of the first chain 62 is attached to the first mast section which is fixed in position, whereas the second end of the first chain is attached to the third mast section, which is moveable.
• the movement of the pulley 64 with the second mast section 28 causes the first chain 62 to ride upward on the pulley 64, resulting in a corresponding movement of the third mast section 30.
• the mast 12 far exceeds the maximum extension of the ram 46.
• the mast may be extended by a multiple of the movement of the ram based upon the number of moveable mast sections present. For example, a mast having three moveable sections may be extend by three times the extension of the ram.
• first mast section is provided with reinforcing spline formations 82 running along the outer edge of the walls thereof. Similar formations may be provided along the other mast sections.
• the lower end of the ram 46 is embedded within the interior of base section 22 and comprises a port for application of pressure thereto.
• alignment formations are shown in further detail.
• One or more alignment formations may be provided in a side wall of a mast section.
• alignment formations are provided in opposing walls of each mast section, typically in each moveable mast section. More specifically, alignment members are provided in four of the eight faces of each of the moveable mast sections.
• the relevant faces of the mast sections are provided with an aperture having a circumferential wall 84 thereabout.
• the aperture and wall 84 define an open-ended recess in which is received a friction member 86.
• the friction member 86 is formed of a body of resilient material such as a rubber or the like which is pressed against the corresponding wall of the adjacent mast section.
• Retaining members 88 are used to hold the friction member within its recess and may take the form of a pair of retaining formations which span the recess opening in the form a cross. The degree to which the friction members protrude from the recess can be adjusted to ensure a close fit between adjacent mast sections.
• Friction members mounted at the mid or the lower regions of each mast section may be oriented to press against the inner face of the radially outer adjacent mast section, whereas friction members mounted at an upper end of each mast section may be oriented to press against the outer surface of the radially inner adjacent mast section.
• Any or every mast section may have a plurality of friction members mounted towards each end thereof and/or along its length.
• the mast can be retracted from its extended condition under gravity. The weight of the mast and the structure attached at its head end may serve to retract the mast as pressure is released in a controlled manner from the cylinder chamber 52.
• a further pulley system may be employed which opposes the pulley system shown in figures 2 and 3. Similar to the pulley system shown in figures 2 and 3, the retraction pulley system may employ a pair of chains located on opposing sides of each section. Such retraction chains may be interposed between the pairs of chains shown in figures 2 and 3.
• the retracting pulley system will be driven against the pressure applied to the cylinder chamber 52.
• a further drive means in the form of a piston/cylinder or else a winch/motor arrangement may be required to drive the retraction mechanism.
• the pressure in the cylinder 52 will typically be released under control as the retraction mechanism is operated so as to maintain a tension in chains 62, 68, 74 and 76.
• Figure 5 shows details of a cable management structure which may be used in conjunction with the present invention.
• the upper end of cable 78 travels in unison with the fourth mast section to which it is attached. This causes slack in the cable to be taken up. It will be appreciated that the length of the slack in the cable is equal to or greater than the maximum length of extension of the mast 12.
• the cable management structure 89 as shown in figure 5, comprises a plurality of open ended housing members 90, each having opposing side wall formations 92.
• the side walls 92 are spaced by top and bottom members 94 which extend between the side walls so as to define an at least partial enclosure for the cable.
• the side walls of the housing members are provided with connection formations in the form of lugs and correspondingly shaped apertures such that the lugs of one housing member can be inserted into the apertures of an adjacent housing member.
• a plurality of housing members can be attached in an end to end arrangement so as to create a length of housing members in the form of a one-dimensional array.
• Each member in the array is hinged relative to the adjacent members in the array such that the cable management structure is multiply pivotable about axes of rotation transverse to the length of the cable.
• the formation of the cable management structure provides lateral stability and hinders deformation of the cable about any axis other than the axes of rotation permitted by the lug-and-aperture arrangement of the housing members.
• the length of cable which is left slack when the telescopic mast is retracted falls in a predictable manner and does not form coils or randomly oriented loops which may snag and resists extension of the mast.
• the ram may not be directly to the moveable mast section but may instead be connected thereto via a pulley system in order to multiply the degree of travel of the moveable mast section relative to the movement of the ram.
• the first mast section preferably shares a one-to-one movement ratio with the ram, which movement is used to actuate further mast sections via a pulley system.
• the telescopic mast system described above is not limited to use with lighting apparatus and may be applied to, for example, wind turbines or the like, wherein the uppermost portion of the mast may be provided with suitable attachment formations for fixation of a wind turbine thereto.
• a retracting mast of this kind may be used for telecommunications applications such as for a telecommunication base station which may support telecommunications equipment for transmission and/or receipt of signals.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Earth Drilling (AREA)
• Wind Motors (AREA)

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• 2008
  • 2008-05-31 GB GB0809977.2A patent/GB2460637B/en not_active Expired - Fee Related
• 2009
  • 2009-03-23 RU RU2010153259/03A patent/RU2010153259A/ru not_active Application Discontinuation
  • 2009-03-23 CN CN2009801199325A patent/CN102046902A/zh active Pending
  • 2009-03-23 AU AU2009252979A patent/AU2009252979A1/en not_active Abandoned
  • 2009-03-23 WO PCT/GB2009/000764 patent/WO2009144439A1/en active Application Filing
  • 2009-03-23 EP EP09754084.3A patent/EP2286045B1/de not_active Not-in-force

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