This invention relates to tensioned structures, for example tensile fabric or filmic structures, for example for billboards, shelters and canopies and tensioned linear structures.
Tensioned fabric and filmic structures are well known, for example to provide shelter from rain or sun. Tensioned fabric or filmic printed materials for billboards are also known, including framing systems providing retention and optionally tensioning of the printed material. Elasticated materials are known including elastic cord sometimes referred to as “shock cord” or “bungee cord”. Means of structural connections to fabrics or films are also known, for example eyelet holes with annular metal reinforcers, or gripper devices, for example Holdon™ two-part gripper devices, or edge seams containing cable. These are used to distribute local stresses in fabric or filmic structures, for example at the connection points to associated tensioned cables, springs or tie rods, for example tie rods comprising a turnbuckle tensioning device.
According to one aspect of one or more embodiments of the present invention, a tensile structural assembly comprises a base support, a guide hook, a loop and a tie, wherein said guide hook is fixed to said base support, wherein said guide hook comprises a guide section and a hook section, wherein said guide section comprises an elongate section, wherein said loop is attached to or forms part of said tie, wherein said loop is retained by said guide hook, and wherein said loop and said tie are in tensile stress.
According to a second aspect of one or more embodiments of the invention, there is a method of assembling a tensile structural assembly comprising a base support, a guide hook, a loop and a tie, wherein said guide hook is fixed to said base support, wherein said guide hook comprises a guide section and a hook section, wherein said guide section comprises an elongate section, wherein said loop is attached to or forms part of said tie, wherein said loop is retained by said guide hook, and wherein said loop and said tie are in tensile stress, wherein said method uses an application tool comprising a recess, said method comprising the steps of:
According to a third aspect of one or more embodiments of the invention, there is a method of assembling a tensile structural assembly comprising a base support, a guide hook, a loop and a tie, wherein said guide hook comprises a guide section and a hook section, and wherein the hook section comprises a sliding hook section capable of movement in relation to said guide section, and wherein said guide section and is fixed to said base support, wherein said loop is attached to or forms part of said tie, wherein said loop is retained by said guide hook, wherein said loop and said tie are in tensile stress, said method comprising the steps of
The tie is optionally a membrane tie, typically comprising a sheet of woven or non-woven fabric or filmic material, or a linear tie, for example an elasticated cable. An assembly comprising a membrane tie typically comprises a plurality of discrete connections to the base support, each discrete connection comprising a guide hook and a loop, in order to retain the membrane tie in tension in orthogonal directions.
Typically, the guide section is of substantially uniform width, and typically of substantially uniform cross-section, along its length.
Optionally, the guide section and the hook section
In a first embodiment of the invention, the guide section and hook section are monolithic.
Typically the guide hook serves as a guide to the application tool or to a fixture attached to the loop or to the tie. Typically the guide hook is fixed to the base structure, for example is screwed or bolted to a billboard structure or a building structure, for example to a brickwork wall, or to a compression member, for example a strut in a space structure, or a pole, for example a flag pole or a lamp pole or other street services pole, or to a vehicle, for example a truck or bus, for example to provide an advertisement tensile structure. The guide hook is typically metallic, for example of steel, stainless steel, aluminum or brass.
The application tool typically comprises two forked prongs, typically to be located on either side of the guide section of the guide hook. Typically, the maximum width between the two prongs is greater than the maximum width of the guide section of the guide hook. The end of each prong of the tool typically comprises a recess into which the loop is temporarily seated during the assembly process. Typically the prongs of the tool are retained in an application tool shaft or handle, which is optionally extended by means of a pole, for example which can be attached to the handle, for example by means of a sleeve screw or bayonet fixing, for example the tool handle comprising a sleeve into which the pole or an end fitting to the pole fits when it is required to extend the length of the application tool. Optionally, the application tool comprises two prongs of variable geometry, which are hinged or sprung, to be capable of being changed from an open position in order to be easily located over the guide section, to then be deflected inwards to bear directly against the sides of the guide section, the change in geometry being effected, for example, by the increasing tension in the loop as it is pushed along the guide section.
Optionally, a fabric or filmic membrane tie will have elastic properties, for example fabric comprising rubber elastic threads. Optionally, a fabric or filmic structure will have reinforced edges, for example a seam, optionally containing a cable. Optionally, a membrane tie comprises an open weave fabric (woven or non-woven) or mesh comprising a plurality of open areas enabling through vision, for example a white mesh, optionally having a black coating on one side, or a black mesh with a white coating on one side, to be imaged on the white side and seen through from the black side, for example to provide a one-way vision effect, for example as supplied by Ferrari, France, or Continental Grafix, Austria. Such see-through fabric can be tensioned across windows and optionally solid areas of a bus or building, to provide an overall advertisement or sign while maintaining the daylight in and view out properties of the window or windows behind the display, coupled with solar heat gain, UV and glare reduction properties, akin to panels according to U.S. Pat. No. RE37,186 (Hill) or U.S. Pat. No. 6,212,805 (Hill). An advantage of the present invention is that an advertising banner over windows, typically see-through, can be quickly removed for window cleaning, and quickly replaced after window cleaning, especially valuable on a bus which is typically washed in an automatic bus washing machine every day. During the washing of the bus, the advertisement is optionally positioned temporarily on a “washing wall” comprising guide hooks of the invention and optionally washed and optionally dried itself, before being replaced on the bus after the bus wash is completed.
A membrane tie typically comprises discrete fixing points, for example eyelet holes or gripper devices, for example Holdon™ two component grippers, one of the components comprising a wedge.
Preferably, each loop in an assembly comprises a highly elastic cord, sometimes referred to as “shock cord” or “bungee cord”, as this imparts additional advantages to one or more embodiments of the invention, for example a positive “snap back” feature when being located over the end of a guide hook. The elastic cord snaps back from the end of the hook section towards the base support when engaging with the hook section, typically accompanied by a distinctive noise which indicates that the required tensile fixing of the loop over the guide hook has been properly effected. The application tool is simultaneously released on snap back. The “snap back noise” is created by the laterally curved outer profile of the hook section stretching the elastic cable of the loop away from the recess in the guide hook, the elastic cable snapping back when reaching the end of the hook section, the elastic cable and/or the application tool being thrown against the base support or a part of the guide hook. Typically, the “snap back noise” is a clearly discernible signal against the background noise, for example of passing vehicular traffic noise or the noise of construction equipment on a construction site. Optionally, a “sounding device”, for example a thin piece of metal, forms part of or is attached to the base support or guide hook, to increase and further distinguish the snap back noise, for example a relatively high pitched noise against the lower pitched drone of passing traffic on a highway to which a billboard is adjacent.
In a first example of the first embodiment of the invention, a billboard tensile structure comprises a plurality of guide hooks fixed to a planar billboard structure, for example metallic hooks screwed to a timber or metal-faced timber sheet to which prior art printed billboard paper posters are otherwise applied. An elasticated loop is typically located over each hook guide, so tensioning a fabric or filmic membrane tie which is typically printed, for example polyethylene fabric printed with UV-cured ink, or PVC-coated polyester fabric printed with solvent or UV-cured ink.
In the prior art sequential fixing of tensile connection points is normally problematic. For example, if an initial number of connecting points are secured with a membrane tie in a slack condition, the required tension needs to be imparted or imposed into the membrane tie and all the discrete tensile connections when forming the residual tensile connections. The residual connections typically could not be made from a remote access position, as an application tool on a pole would have minimal lateral stability. The invention enables the membrane tie to be temporarily located in a relatively untensioned or slack condition onto the guide hook, when the required force can be applied in a controlled manner not requiring any lateral restraint to be imposed by the application tool or pole, which only requires an axial force to be applied. The guide section of the guide hook and the two-pronged application tool work together with the loop, typically enabling a much greater force to be applied to the loop to fix it over the hook section of the guide hook, with typically much higher residual tensile forces in the loop and tie than provided by prior art methods of fixing loops to restraining hooks. Optionally, when the loop is progressively pushed with the application tool along the guide section of the guide hook, the tension in the loop draws the two prongs into direct contact with the side of the guide section, providing the prongs can be so deflected, for example being unconnected at their ends and relatively flexible.
The guide section preferably eliminates the otherwise inevitable tendency of the end of an application tool to be laterally unstable, especially if affixed to the end of a pole. Stability in the direction perpendicular to the base support is provided by the angle of the application tool against the guide section or the base support to which the guide hook is fixed. Optionally, stability in this direction can be additionally provided by a recessed groove on one side or preferably both sides of the guide section of the guide hook, for example the guide section being a ‘T’ section or comprising a recess on each side or a section of the similar shape to a railway rail, into which lugs on the application tool, i.e. one or more sections projecting at on the application tool, are located. Optionally, the end of the guide section of the hook is tapered, to assist the initial locating of the application tool onto the guide section of the guide hook. Preferably, the guide section has projecting edges to resist wear and tear of the base support and to provide a smooth bearing surface for the two prongs being pushed up the guide section, for example similar to a rail section or a profiled section used to make door bolts. Preferably the side projections form a backplate to the guide hook which extends up to the end of and optionally beyond the hook section, to act as a receptor plate to the impacting application tool prongs upon snap back, optionally also acting as a sounding device. Typically, the longitudinal axis of the guide hook is aligned or orientated to allow an axial force to be applied to the handle of the application tool or any extension pole, from an access position below the billboard. Optionally, a swivel section or rotational capability can be incorporated into the end of the application tool, for example by means of a universal or ball joint, to enable a loop to be located over a guide hook by a force applied from a position which is not aligned with the longitudinal axis of the guide hook.
To release a loop from a guide hook, for example in dismantling a structure or replacing a tie, one of the application tool prongs is optionally located between one side of the loop and guide section of the hook and pushed towards the hook section until the loop is released. Preferably a purpose-made release tool is used, typically comprising an axial single prong with a single recess to support the loop cable.
Optionally, a projecting support is provided on the base support to eliminate or reduce flapping of the membrane tie, for example under windy conditions. The projecting support optionally has a surface of single or double curvature and is optionally a solid support, for example comprising a foam material, or is optionally a framework, for example a lattice of timber members, or optionally comprises discrete support positions, for example discrete hemispherical projections from the base structure.
Optionally the base support or a projecting support comprises a transparent material behind which illumination is provided, for example to provide a back-lit illuminated billboard sign on a billboard structure that was previously not illuminated.
In a second embodiment of the invention, the guide hook comprises a hook section which is moveable in relation to the guide section, typically by a sliding action along one axis, for example by adaptation of a sliding bolt action. In this embodiment, the loop is located over the hook and the hook is then pushed, thus extending and increasing the tension in the loop, until it reaches the end of travel or restraint on the guide section and is fixed in the extended position, for example by rotation of the guide hook or by the activation of a spring restraint mechanism. The pushing of the guide hook optionally is assisted by an application tool, for example to obtain extra “purchase” or pushing force than with just use of the hands, or for extended reach, for example at the top of a billboard. This embodiment has the advantage that the guide hook is restrained by the guide section both parallel to and perpendicular to the base support, for example by means of a slotted barrel, directing the application of the pushing force to extend and thereby tension the loop.
The tensile structures of one or more embodiments of the invention are typically temporary, for example comprising:
(i) a billboard assembly comprising an imaged membrane tie, and
(ii) a canopy, and
(iii) a flag pole, and
(iv) an advertisement assembly comprising a window.
Additional and/or alternative advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, disclose preferred embodiments of the invention.
Referring now to the drawings which form a part of this original disclosure:
The membrane tie 21 optionally has significant elastic properties itself and optionally eyelet hole 25 comprises the loop according to an alternative embodiment of the invention.
As another example of a discrete connection,
Dismantling structures of the invention or replacing a tie typically involves locating one prong of an application tool between the loop and guide hook and pushing the loop until disengaged from the guide hook. Optionally a purpose-made removal tool 80 can be used for this purpose, for example as illustrated in
Optionally, for example in a billboard tensile structure of
Optionally, there is selective use of the invention on just one of the opposing sides being tensioned (two sides out of four for a rectangular membrane tie or one side if an alternative tensioning system is being used in one direction).
Guide hooks are typically of relatively short length, for example from 2-12 in. (50-300 mm). However, they can be of any length to suit the degree of convenience required in locating the application tool over the guide section, for example they may run the full height of a flagpole or billboard, for example using a progressively extendable pole, for example a telescopic pole, for ease of transporting application tools.
One or more embodiments of the invention reduce the risk of finger trap injury of manual application of loops to hooks while substantial tensile forces are being manually resisted. One or more embodiments of the invention also enable loops to be applied to guide hooks in positions remote from erector access positions, for example billboards can be posted from an access area at ground level or on an access platform immediately below a billboard without requiring ladder access. Ladders can be a safety risk to erectors, especially when applying a substantial force, for example to effect a tensile connection when supported on a ladder rung. Similarly, canopy tensile structures can be erected from ground level, for example affixed to guide hooks on a building or buildings, for example to provide an infill walkway canopy between two buildings. As another example, flags and banners can be fixed to poles with shock or bungee cord, reducing or eliminating the need for rope and pulley arrangements at ground level where they are liable to vandalism.
One or more embodiments of the invention provide a simpler, safer and more economic tensile structural system than prior art systems, for example of forming a billboard structure and replacing membrane ties comprising billboard advertisements at frequent intervals.
One or more embodiments of the invention enable the adoption of environmentally friendly materials, for example polyethylene fabric printed with UV-cured ink, which can be recycled after use, compared to prior art systems, for example self-adhesive PVC film printed with solvent-based PVC inks, which are very undesirable materials, requiring landfill with the attendant chemical migration problems of PVC.
In summary, various embodiments of the invention can be used in many different types of tensile structures and the embodiments illustrated are not limitive. The foregoing description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. To the contrary, those skilled in the art should appreciate that varieties may be constructed and employed without departing from the scope of the invention, aspects of which are recited by the claims appended hereto.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2008/003146 | 9/17/2008 | WO | 00 | 6/29/2010 |
Number | Date | Country | |
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60972880 | Sep 2007 | US |