The present invention provides a deck panel supportable on a pair of spaced parallel support (catenary) wires and a platform of a plurality of the catenary wires carrying a multiplicity of the deck panels. It also provides a T-clamp useful e.g. in platforms of the above kind for attaching tension members e.g. slings to the wires. It further provides an in-line tensioning device for catenary cables and its use in platforms supported by catenary cables.
U.S. Pat. No. 5,299,655 (Margaritis) discloses suspended structures providing a workplace beneath bridges and other like structures. Cables are each fixedly connected at opposite ends to said underlying bridge supports and lie parallel to one another in a substantially common horizontal plane spaced a predetermined distance below the substructure, tension in the cables being adjustable by means of turnbuckles. The two outermost cables are spaced from one another by a distance at least substantially as great as the width of said bridge. Load-bearing flooring is supported by the cables and extends the full width between the outermost cables and the full length between the bridge supports. The floor is constructed of chain-link fence which is unrolled so as to lay on the cables, and is wrapped around the cables and secured thereto with clips, after which the chain-link fence floor is covered with nylon tarpaulin or other fluid-impermeable material.
U.S. Pat. No. 5,730,248 (Apostolopoulos) aims to provide an improvement on such platforms by reducing the time needed to erect and dismantle them, and to provide rigid support for workmen standing or walking thereon. Flooring sections or panels of sheet material of elongated rectangular shape corrugated for strength at right angles to the cables together form a platform, are supported by the under-bridge longitudinal cables in side-by-side relationship and are removably connected thereto. Each connection is formed by a plate which engages the upper surface of a panel and a generally U-shaped member which is attached to the plate to extend downwardly therefrom to be received in a panel opening and to receive the cable. The free end of the member is threadedly attached to another plate wherein the two plates generally cover the opening with the cable securely received between the legs of the U-shaped member. U.S. Pat. No. 6,138,793 (Apostolopoulos) provides a connector assembly which has a manually operated lever for selectively placing the connector assembly in clamped or un-clamped positions relative to the cable and flooring section. However, these connector arrangements have been criticised as unduly complex. The first described arrangement it requires two parts to be assembled as well as a nut which must be screwed onto the free end of the member, i.e., a total of three separate parts as well as an electric or other wrench for applying the nut sufficiently tight. The second lever-based arrangement requires two parts to be assembled as well as a pin (or nut and bolt) for added safety.
A rope clamp having a pair of jaws for clamping about a rope or cable and having an eye for attachment of a second rope is shown in U.S. Pat. No. 0,779,019 (Agobian). The disclosed utility is for uniting ends of ropes. Forming an attachment at an intermediate position along a rope or cable for a second rope, wire, chain or the like in tension in a direction out of alignment with the first rope about which clamping is effected is neither disclosed nor suggested. A clamp having a pair of jaws for fastening about a wire rope and having a hook attached to one of the jaws for attachment of a second wire rope, e.g. a guy rope is disclosed in U.S. Pat. No. 0,928,367 (De Witt). However, it is apparent that load on the hook from the guy rope in a direction out of alignment with the main rope tends to pull the jaws apart rather than tighten them about the rope. By way of background, a further clamp for gripping a cable or rope based on a pair of jaws is shown in U.S. Pat. No. 4,143,446 (Down). The jaws are screw clamped together and can accommodate in-line an accessory permitting attachment of a hook, eye, shackle, swivel or the like. However, it will be apparent from the drawings that the Down attachment only enables this to be achieved at an end of the rope.
Some embodiments of the invention provide panels which can be fitted easily and rapidly to catenary wires with minimal gaps, or with gaps of predetermined relatively small dimensions, between their ends to form a load platform.
Other embodiments of the invention provide panels that can be fitted to at least three support wires in rows and columns with at least two adjacent panels having a common support wire, the panels being configured so that they may be fitted either in aligned rows or in a staggered arrangement.
It is a further object of the invention to provide a platform comprising panels clipped between catenary wires, wherein the effects of failure of a catenary wire are relatively localised, support along the length of the platform being at least partly retained.
It is a further object of the invention to provide platforms supported by catenary wires in which the cables are optimally adjusted.
A yet further object of the invention is to provide friction clamps e.g. for use in association with load-carrying members e.g. straps, wires, chains or slings that are of improved structure and properties.
It will be appreciated that the invention has a number of diverse aspects, and individual embodiments may not achieve ann or indeed any of the above objects.
In one aspect the invention provides a decking panel having first and second ends and fasteners at each end for releasably clipping the panel to a pair of wires by which it is to be supported, said fasteners comprising hooks for supporting the panel on the wires and catch assemblies each including at least one finger for resisting lift of the panel from the wires, the catch assemblies being covered by treadplates hinged to the panel with free ends facing outwardly and at least partly overlying the hooks, raising the treadplates from the panel providing access to the catch assemblies. Clipping can be achieved without the use of tools, which is an advantage in such areas as an underdeck of jetties, rigs, bridges and pipe racks. The underdeck can provide a solid and stable work platform that feels like scaffolding and users may be able to carry out a variety of heavy work tasks off the deck as if it were scaffolding.
In a further aspect the invention provides a decking panel having: first and second ends; and fasteners at each end for releasably clipping the panel to a pair of wires by which it is to be supported, said fasteners comprising hooks for supporting the panel on the wires and at least one catch for resisting lift of the panel from the wires; wherein the hooks and a catch or catches at one end are offset from the hooks and a catch or catches at the other end.
In a further aspect the invention provides a decking panel having: first and second ends and fasteners at each end for releasably clipping the panel to a pair of wires by which it is to be supported; said fasteners comprising hooks for supporting the panel on the wires and catch assemblies at each end of the panel for resisting lift of the panel from the wires, each catch assembly comprising a cross-member pivotally supporting one or more levers each carrying a catch finger, the or each lever being rotatable between a raised position where the finger or fingers are clear of the hooks and a lowered position where the finger or fingers register with the hooks from underneath for clamping a support cable between the hooks and the fingers; and treadplates at each end of the panel, hinged thereto at pivot axes spaced from the ends of the panel and with free ends facing towards the ends of the panel, the treadplates being liftable from a normal lowered position in which the or each catch assembly is concealed by the treadplate to a raised position in which the or each catch assembly is user-accessible.
For use in an inter-tidal zone there may be provided a decking panel for forming a load platform, said panel having first and second ends and fasteners at each end for releasably clipping the panel to a pair of wires by which it is to be supported, the panel comprising a pair of longitudinal styles, cross-members between the styles and decking in the form of a grating or expanded metal.
In a further embodiment the invention provides a load platform comprising spaced parallel wires supporting a plurality of panels as defined above.
In a further aspect the invention provides a T-clamp for fitting to a rope in tension and for attachment of a member which in use is loaded in a direction transversely of the rope, said clamp comprising: first and second elongate members; hinge formations at one end of said members forming parts of a hinge that connects the members together for movement between an open position in which the rope is insertable into and removable from the clamp and a closed position in which the first and second members contact one another and the rope is retained in the clamp; first and second clamping jaws in said members for closing about and frictionally engaging the rope, one side of each clamping jaw being adjacent the hinge; first and second stem regions of each of said members arising from sides of the clamping jaws opposite to the hinge and extending away from the hinge in a direction transversely of the clamping jaw; and first and second hook or eye regions extending from ends of the first and second stem regions opposite to the hinge and together defining an a hook or eye for receiving an eye or hook of the member, load on said first and second eye regions urging the clamp towards its closed position.
The invention also provides in combination a clamp as aforesaid and a wire or chain sling, the first and second members having eyes and the sling having a hook.
A load platform according to the invention comprises support wires, decking clipped to the support wires for providing the platform, and one or more slings or straps attached at their upper ends to a structure beneath which the load platform is slung and attached at their lower ends to the wires at one or more intermediate positions along their length, the attachment being by T-clamps as aforesaid and lower ends of the slings being said members, the clamps being configured to frictionally engage the wires for impeding the wires from travelling through them.
In another embodiment the invention provides a load platform comprising support wires and panels clipped to the support wires for providing the platform, wherein adjustable support chains are connected to the support wires at intervals between their ends for supporting vertical load, and the adjustable support chains are connected to support wires by friction clips that surround the support wires and frictionally engage therewith to inhibit the support wires from being pulled through them in the event of wire failure.
A further aspect of the invention provides a platform comprising: decking panels each having first and second ends and each comprising (a) fasteners at each end for releasably clipping the panel to a pair of wires by which it is to be supported, said fasteners comprising hooks for supporting the panel on the wires and catch assemblies for resisting lift of the panel from the wires, and (b) treadplates at each end of the panel, hinged thereto at pivot axes spaced from the ends of the panel and with free ends facing towards the ends of the panel, the treadplates being liftable from a normal lowered position in which the or each catch assembly is concealed by a treadplate to a raised position in which the or each catch assembly is user-accessible; at least three spaced parallel wires supporting a plurality of decking panels arranged in at least two columns, adjacent decking panels of different columns having a common support wire; one or more slings or straps attached at their upper ends to a structure beneath which the platform is slung and attached at their lower ends to the support wires at intermediate positions along their length; and clamps providing attachment of the lower ends of the slings or straps or legs thereof to the support wires, the clamps being configured to frictionally engage the wires for impeding the wires from travelling through them, the clamps being located on the support wires within the widths of individual panels and free edges of treadplates of adjacent panels at a common support wire being spaced apart to permit portions of the clamps attached to the support wire to pass upwardly between the treadplates.
It will be appreciated that in this embodiment by locating the clamps on the support wires within the widths of adjacent panels it is not necessary to space apart decking panels of the rows at the sling or strap positions. In embodiments upper ends of the clamps are formed with eyes for receiving hooks at the lower ends of the slings or straps or legs thereof. In further embodiments the clamps may comprise first and second members hinged together below the support wires, said members having concave clamping regions for fitting about the support wires and stems extending from the clamping regions to above the treadplate, portions of the stems defining eyes that coincide for receiving hooks of the slings or strap or legs thereof.
A further embodiment of the panel comprises a decking panel having first and second ends and fasteners at each end for releasably clipping the panel to a pair of wires by which it is to be supported, the panel comprising decking and a support framework including a pair of longitudinal styles, wherein the upper regions of the styles have upstanding formations and lower regions of the styles having matching recesses or sockets in which at least uppermost regions of the upstanding formations can be received, whereby when one panel is stacked on another, displacement of the upper panel laterally is resisted.
Another aspect of the invention provides a load platform comprising support wires and panels clipped to the support wires for providing the platform, wherein the support wires are secured to tensioners configured for sensing tension and setting tension in the wires to a desired value. Although turnbuckle tensioners are known, the applicants have not found a turnbuckle tensioner with a built-in load cell or other tension-measuring device. In applications involving load-carrying generally horizontal wires in tension, as in the present load platforms, it is desirable to be able to set a determined tension in the wires without over-tensioning.
A yet further embodiment of the invention comprises a tensioner for a support wire, rope or the like comprising a body and oppositely acting screw jacks together extensible from and retractable into the body on rotation thereof, attachments at the ends of the screw jacks for wire eyes or the like, and a measuring device for measuring tension applied to the wire.
It will be appreciated that the features set out above may be used in combination with one another and in sub-combinations. Thus any of the preferred decking panels, support chain and clamp arrangements, tensioners and load platform arrangements may be used in association with one another and, for example the support chain and clamp arrangements and the tensioners may be used with other types of decking panels.
Thus the invention further provides a load platform comprising support or catenary wires and panels clipped to the catenary wires for providing the platform, wherein adjustable support chains and clamps are connected to the catenary wires at intervals between their ends for supporting vertical load, and the adjustable support chains are connected to catenary wires by friction clips that surround the catenary wires and frictionally engage therewith to inhibit the catenary wires from being pulled through them in the event of wire failure, the catenary wires being secured to tensioners configured for sensing tension and setting tension in the wires to a desired value.
The above decking panel in embodiments is generally rectangular and comprises a pair of longitudinal styles and cross-members between the styles. The cross-members may include ladder-like cross-members and/or diagonal cross-members defining a truss-type structure.
Embodiments of the styles are extrusions in aluminium. Such extrusions may in embodiments each comprise a region of box section into which the hooks fit, portions of the region of box section defining outer and inner webs spaced apart transversely of the panel, one hook at each end of the panel being fastened to the outer web of one of the styles and the other hook at each end being fastened to the inner web of the other of the styles. Such extrusions may further comprise portions of the region of box section that define an upper generally horizontal web from which an upstanding wall arises and portions that define a lower generally horizontal web formed with a recess into which at least uppermost regions of the upstanding walls can be received, whereby when one panel is stacked on another lateral displacement of the upper panel is resisted. Each style may be formed adjacent each end at its inner vertical web with fixing formations for attachment of fastening plates of a catch assembly and/or for attachment of hooks, and may be formed adjacent one end at its outer vertical web with fixing formations for attachment of a hook.
In alternative embodiments the styles are of rolled steel, e.g. in channel, I or Z-section. In this case, the styles may each comprise a portion defining a web to which hooks are attached, one hook at each end of the panel being fastened to the web of one of the styles directly or at a relatively small spacing, and the other hook at each end of the panel being fastened to the web of the other of the styles with a spacing that is larger than the spacing for said one style, the styles and hooks being configured so that the hooks at one end of the panel are offset transversely of the panel relative to the hooks at the other end of the panel. The styles may further comprise portions that define an upper generally horizontally-directed web from which upstanding pins, ribs or other formations arise and portions that define a lower generally horizontally-directed web formed with recesses or sockets into which at least uppermost regions of the upstanding pins, ribs or other formations can be received whereby when one panel is stacked on another lateral displacement of the upper panel is resisted.
In embodiments of the above panel, the cross-member carries a pair of levers spaced apart transversely of the panel and interconnected at or adjacent their ends facing away from the support cable by a handle. For ease of fitting to support wires in both aligned and staggered arrangements, the pair of levers is conveniently spaced apart by about one third of the width of the panel. Each finger may be formed with a recess defining an upwardly-facing hook for engagement with the underside of the support cable or it may have a plate-like surface engageable with the support wire, friction between the fingers and the support wire inhibiting lateral displacement of the panel.
Decking may be wooden e.g. of plywood, may be of metal or may be of expanded metal especially where the decking is to be used in tidal conditions and may be submerged at some states of the tide.
For support at intermediate longitudinal positions the above load or work platform may further comprise one or more slings or straps attached at their upper ends to a structure beneath which the load platform is slung and attached at their lower ends to the support wires at one or more intermediate positions along their length. Lower ends of the slings or straps or legs thereof may be attached to the support wires between adjacent pairs of panels or may be attached to the support wires at locations within the widths of individual panels. In either case, the lower ends of the slings or straps or legs thereof may be attached to the support wires by clamps (e.g. two-part hinged T-clamps) configured to frictionally engage the wires for impeding the wires from travelling through them. Free edges of treadplates of adjacent panels at a support wire may spaced apart for access of the support wire and upwardly-facing portions of clamps attached to the support wire may extend between the treadplates.
For tensioning the support wires the tensioners may comprise a body and oppositely acting screw jacks together extensible from and retractable into the body on rotation thereof. They may further comprise a ratchet for controlling rotation of the body and a handle for effecting rotation, and their opposed ends may incorporate bifurcated shackles and pins for attachment to wire eyes or the like, the in-line sensor being between one of the screw jacks and a shackle.
With reference to the above clamp, there may be further comprised apertures in the first and second stem regions adjacent said first and second hook or eye regions for receiving a retaining bolt. In some embodiments the first and second stem regions and the first and second hook or eye regions together define planar surfaces that are in contact in the closed position. To reduce point loads and permit the member to be at an angle relative to the clamp, in some embodiments internal faces of the first and second hook or eye regions at least adjacent ends of the first and second members opposite to the hinge are internally profiled to define a continuous curved surface for receiving an eye or hook of the member.
In general in relation to load platforms, the decking may comprise panels clipped or otherwise releasably fastened to the wires, in which case embodiments of the panels comprise a pair of longitudinal styles and cross-members between the styles. Lower ends of the slings or straps or legs thereof in some embodiments are attached to the support wires between adjacent pairs of panels and in other embodiments are attached to the support wires within the widths of individual panels. Alternatively in some embodiments the decking comprises tensioned netting clipped to the support wires, e.g. polyester netting.
How the invention may be put into effect will now be described by way of example only with reference to the accompanying drawings, in which like parts are so far as practical represented by the same reference numerals, and in which:
The arrangement of
As is apparent from
Styles 24 which are conveniently aluminium extrusions are shown in enlarged section in
Decking 40 is laid on the ladder-type or other framework structures and is attached thereto, the decking being of timber, metal sheet or metal mesh or grating, aluminium or steel being preferred. Where the platform is of mesh or grating, it may conveniently be used to erect a platform in tidal conditions where it will be covered with water at some states of the tide. In the present embodiment the decking may be of plywood.
Opposed ends of the deck panels are formed with hooks 28a, 28b, 30a, 30b attached to the styles 22, 24 for fitting opposed ends of the deck panels onto respective pairs of catenary wires 10a, 10b or 10b, 10c as shown in
Each deck panel is provided at each end with a catch sub-assembly or operating mechanism 32, 34 for retaining the panel in position on its catenary wires against lifting or other displacement forces e.g. from wind or in the case of a load platform that may be submerged at some states of the tide from estuarine or tidal currents. The catch sub-assemblies are normally covered by hinged treadplates 52 which normally lie flat but which can be rotated upwards to give access to the underlying catch sub-assembly 32 or 34. Retaining fingers 36a, 36b, 38a, 38b are movable into contact with the catenary wires from below to prevent the deck panels being inadvertently lifted off the catenary wires e.g. in high winds. Again as seen in
As apparent from
A first cross-member 64 extends between styles 22, 24 immediately behind the operating levers 42 and carries hinges 66. A second side of the hinges attaches to a second cross-member 68 of angle section fitted to the treadplate 52. Thereby the treadplate 52 is hinged to the panel for rotation about an axis spaced inboard and slightly above the pivot axis for the release mechanism provided by cross-member 54. As previously explained, it will normally lie flat as shown supported by the horizontal top walls of the styles 22, 24 as in
Laying a deck panel on its catenary wires is a two-person operation. A person at each end of the panel lifts the treadplates 52 to a vertical position, grips handle 44 and lifts that handle to a vertical position, rotating the fingers 38a, 38b clear of hooks 40a, 40b. The handles 44 are then conveniently positioned for carrying the panel. At the start of laying, the panel is positioned over the catenary wires e.g. 10a, 10b and lowered into place. Release of the handles 44 permits the opening mechanisms to rotate by gravity until the fingers 36 engage the catenary wire, after which a small force on the treadplates 52 allows them to fall under gravity into their fully lowered position. The mechanism is therefore robust and simple to operate, and it is resistant to inactivation as a result of paint or other materials which are likely to become deposited on it during service and which in other designs of deck panel jam the release mechanism and may prevent operation.
Deck panels in aluminium according to the embodiments described above may be lightweight e.g. about 14 kg/m2 and may for example have a loading capacity of 0.5 kN to 5.5 kN UDL/m2 depending upon the requirements of a particular job. They are easily maneuverable and easy to rig, and installation time may be reduced compared to scaffolding.
The combination of catenary wires, support straps and clamps is also useful where polyester tension netting is provided between catenary wires in place of the panels described in the previous Figures.
It has been found that the catenary wires of load platforms of the present kind give optimum performance and stability when the catenary wires that provide support are tensioned at or adjacent a best value which will, of course, vary depending on the particular structure under which the load platform is to be slung, and that excessively high or low tensions are better avoided. For that purpose the catenary wires may incorporate in-line load cells of the kind illustrated in
Between the end of jack screw 104 and shackle 114 the end fitting 108 is an in-line load cell incorporating a pre-calibrated spring-operated load measuring arrangement providing an output by movement of indicator member 128 through a calibrated window, the member indicating by its position the load which e.g. may be between 0 and 30 kN. It will be appreciated that other types of load cell may be employed, e.g. based on strain gauges and electronic devices including a display, but a simple spring-loaded device may be more convenient especially where the platform is to be in place for extended periods and is subject to adverse weather. However a transducer could be incorporated to provide an overload indicator alarm.
In
Although aluminium is a preferred material, generally square sections in steel may be rolled for some markets where steel is more practical and the rolled sections may have complementary protuberances and recesses on their upper and lower faces which interfit to allow stable stacking as described above although the precise shapes for aluminium cannot be duplicated in rolled steel and rolled steel styles will differ from those shown Rolled steel sections may be of any conventional shape provided that a vertical web portion is provided, and they may, for example be of channel, I or Z-section, channel section being convenient in some embodiments. Further sections are C- or channel section with their flanges formed at their ends with return (in-turned) regions or flanges which in some embodiments can significantly increase strength and stiffness. In
In
A hook 302, e.g. a safety hook, of a chain sling is insertable into the eye 292 and provides a lower connection for the chain sling. The eye region 292 is generally oval or otherwise has extended height to allow the T-clamp to sit generally vertically on support wire 10b, and the hook 302 is configured to be rotatable in any direction at an angle of up to about 45° to the vertical, thereby permitting the loading on the individual eye-regions 294, 296 of the clamping members to be equlised. It will be appreciated that if a T-clamp as shown here is fitted about a support wire 10b, hook 302 is engaged therewith and the cable 304 is tensioned, then the clamp will be held tightly about the wire irrespective of whether bolt 301 has been inserted and a substantial clamping force is exerted by simple tension applied to the eye regions 294, 296, so that at least a temporary fixing to the wire 10b can be made with a minimum of labour. The retaining bolt and the sockets 288-290 are configured so that for an intended support cable the clamp cannot be over-tightened, and one of the major purposes of bolt 301 is to prevent a clamp once fitted to support wire 10b from being inadvertently dropped before attachment of a hook or other tensioning device.
It will be appreciated that various modifications may be made to the embodiment described herein without departing from the invention, the scope of which is defined by the accompanying claims.
Number | Date | Country | Kind |
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1118568.3 | Oct 2011 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2012/052664 | 10/26/2012 | WO | 00 | 4/17/2014 |