GB2269407A - Floor plate fixing to open mesh flooring - Google Patents

Abstract

A fixing device (16) for holding down a floor plate (13) to an underlying open mesh structure (10) is positioned in a mounting hole (14) provided in the floor plate (13) and extends through a space defined between a pair of adjacent mesh bars underlying the mounting hole. The device can be moved into clamping engagement with one of the mesh bars and upon tightening holds down the floor plate to the mesh structure. The fixing device comprises: a cover plate (18) which is rotatable in the mounting hole (14); a guide (19) carried by the cover plate (18); a threaded fastener (20) extending downwardly through the guide (19) and being rotatable therein; and an internally threaded clamping element (22) fitted on the lower end of the threaded fastener (20) and having a laterally projecting formation (23) to engage the lower edge of one of the mesh bars (11a). <IMAGE>

Description

FLOOR PLATE FIXING TO OPEN MESH FLOORING This invention relates to a floor plate fixing device for fixing a floor plate to an underlying open mesh support.

The term "open mesh support" used herein is intended to include a mesh, grid, grate, grating or other support made up from bars, rods or other elongate members held together in a rigid assembly and with spaces defined between at least some of the adjacent members.

Mesh-flooring is used widely e.g. in industrial buildings as walkways alongside machinery, fire escapes, in ships, marine installations, oil and gas drilling rigs and accommodation platforms, in situations where a rigid support for traffic is required, but where the ability of the support to provide rapid water drainage through the spaces in the flooring is desirable. This is particularly advantageous on drilling rigs or platforms in the North Sea or other marine environments, where mesh flooring is robust and easy to assemble, and provides for rapid drainage of seawater or rainwater. However, a major disadvantage of use of mesh flooring on oil / gas platforms is that if any eruption of seabed gas takes place and / or in a fire situation, toxic and noxious gases generated can easily flow upwardly through spaces in the mesh flooring.

Therefore, while mesh flooring is still useful for rigs, platforms etc, there is a requirement for at least some areas of the flooring e.g. predetermined escape routes, to be clad with cover plates so as to reduce the volume of gas which can escape upwardly through the mesh in these areas.

The assembly of the cover plates to the mesh flooring would best be carried out on site, at areas where this is required, and for ease and speed of assembly it would be highly desirable to provide a fixing system using "blind fasteners" so that the fixing down of the floor plates could be carried out simply from above the floor and without the need for any manual operations to engage the under floor components of the fasteners. Evidently, use of non-fluid fasteners i.e. simple bolts or threaded fasteners would require the lower end of the fastener -(the head of the fastener or a "nut") to be held by a tool while tightening the upper end of the fastener, or vice versa.

Blind fasteners are well known for joining two components together when access can only be had from one side of an assembly, but existing designs of blind fasteners will be of no use in on site assembly of cover plates to mesh flooring. Thus, mounting holes will be formed at suitable positions in any floor plate, and when the plate is positioned at a required location on the mesh flooring, it will be impossible to predict that the same mesh profile i.e.

mesh bar separation will appear below each mounting hole, and in practice it will usually be the case that there will be variations from one possible fixing location to another.

The fixation is still further complicated when the mesh flooring includes (as is often the case) both parallel mesh bars, and also intermediate bars which take-up nonrectilinear shapes in the spaces between adjacent parallel bars e.g. sinuous shapes as seen from above, or straight sided V-shapes.

Therefore, one mounting hole may be found to be located with its centre substantially directly above a mesh bar, so that downward movement of any blind fastener would be obstructed, whereas another mounting hole may have its centre laterally spaced from any underlying mesh bars by so large a distance that any blind fastener passed downwardly through the hole may be unable to make any type of clamping engagement with any part of the underlying mesh flooring.

Accordingly, it would not presently be possible to employ existing designs of blind fasteners to be sure that satisfactory fixation can take place at each of the mounting locations provided in the floor plates which are to be held down on the open mesh flooring.

There is therefore a clear need to provide a blind fastener fixing system which can be used to hold down a floor plate onto underlying mesh flooring with the fasteners being taken through mounting holes provided in the floor plate and into clamping engagement with parts of the underlying mesh flooring, Aespite the possibility of there being variations in the mesh profile from one mounting hole to another.

According to the invention there is a fixing device for holding down a floor plate to an underlying open mesh structure built-up from a number of mesh bars, at least some of which are laterally spaced from each other, said fixing device being receivable by a mounting hole provided in the floor plate and being capable of extending through a space defined between a pair of adjacent mesh bars underlying the mounting hole, and being movable into clamping engagement with one of the mesh bars and upon tightening to hold down the floor plate to the mesh structure, in which the fixing device comprises:: a cover plate which is rotatable in said mounting hole about an axis extending upwardly through the cover plate; a guide carried by the cover plate and extending downwardly therefrom in a direction generally parallel to the rotational axis of the cover plate, said guide being spaced laterally from said axis; a threaded fastener to extend downwardly through said guide and being rotatable therein; and, an internally threaded clamping element to be fitted on the lower end of the threaded fastener and having a laterally projecting formation to engage the lower edge of one of the mesh bars, whereby (1) upon initial assembly the guide and threaded fastener can be moved downwardly through any space available below the mounting hole between adjacent mesh bars, (2) thereafter the clamping plate is rotatable until the guide and / or the clamping element come into engagement with a side face of one of the mesh bars and so as to bring said formation of the clamping element into registry with the lower edge of the mesh bar, and (3) finally the fastener is tightenable in order to clamp the plate to the mesh structure.

The fixing device of the invention therefore functions as a "blind fastener", whereby all necessary initial manipulation of the device, and final tightening, can take place from above the floor plate to bring the clamping element into engagement with the lower edge of the mesh bar, and then be clamped thereto.

Preferably, the cover plate is rotatable in a seating formed in the mounting hole, and conveniently the seating comprises a frusto-conical shoulder onto which a bevelled edge of the cover plate can be seated. However, it is within the scope of the invention for the cover plate to be rotatable within a mounting portion of the device, said mounting portion being non-rotatably mounted in the mounting hole in the floor plate.

The cover plate therefore may have a circular shape, with its axis of rotation passing through the centre of the circle.

To facilitate rotational adjustment of the cover plate for the purposes of bringing the clamping element into cooperation with any suitable one of the underlying mesh bars, a drive connection may be formed on or in the upper surface of the cover plate. By way of example, this may comprise a hexagonal socket formed in a central region of the cover plate, to be engaged by an Allen key.

The guide is preferably provided with an enlarged mouth into which a head of the fastener can be received, so that the head does not project upwardly from the surface of the cover plate. Further, the cover plate is preferably housed in the mounting hole in such a way that it also does not project upwardly of the surrounding surface of the floor plate. This will serve two functions: first it will provide assurance, when tightened in position, that a satisfactory clamping has taken place; and secondly it will avoid the risk of tripping up any person walking over the floor plate, or of interfering with sliding movement of any goods over the floor plate, or rolling of any goods over the floor plate on a trolley or the like.

The clamping element effectively comprises a specially designed internally threaded "nut", and the laterally projecting formation may comprise a flange or tongue having a trough-shaped recess formed in its surface onto which the lower edge of a mesh bar can be seated.

To assist the clamping engagement with the underside of the mesh bar, the clamping element may have an upstanding lug which is movable into engagement with a side face of the mesh bar upon rotation of the fasteners, and following the rotational adjustment of the cover plate. The engagements of the lug prevents further rotation of the clamping element which is then drawn upwardly into clamping engagement with the underside of the mesh bar.

The guide preferably takes the form of a tube which is rigidly attached to the cover plate, and conveniently is formed in one piece with the cover plate.

The guide tube therefore preferably permits the threaded fastener to be freely rotatable therein.

One embodiment of fixing device according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawing, in which: Figure 1 is a plan view, partly broken away, illustrating the use of a fixing device according to the invention in order to hold down or clamp a floor plate to an underlying open mesh flooring structure; and, Figure 2 is a side view of the assembly of the floor plate to the mesh structure.

Referring now to the drawing, there will be described an embodiment of fixing device in the form of a "blind fastener" which can be used to hold down a floor plate to an underlying mesh structure which is built-up from a number of mesh bars. The mesh structure is designated generally by reference 10, and the right hand part of Figure 1 shows a typical type of mesh flooring structure with which the invention may be used, which comprises mesh flooring of the type used on oil / gas drilling platforms and accommodation platforms in the North Sea. As can be seen, the mesh structure is built-up from a number of parallel bearing bars 11, which will be arranged rigidly within a rectangular frame, and there are also intermediate bars 12 which add strength and rigidity to the assembly, and which are located in the spaces defined between the bars 11.The intermediate bars 12, in the illustrated arrangement, comprises a generally V-shape, although there other shapes adopted for the intermediate bars, including sinusoidal shapes.

It will be evident that, depending upon the mounting position selected for a blind fastener above the structure 10, the centre of any mounting hole may be located directly above one of the bars 11 or 12, or with a different mesh profile from one mounting hole to another, and particularly different lateral spacings between adjacent bars in the region immediately below the mounting hole.

It is the main purpose of a fixing device according to the invention to hold down a floor plate to an underlying mesh structure at locations where this may be required e.g.

along predetermined walkways provided by the mesh structure, and part of a metal floor plate is shown in Figures 1 and 2 and designated generally by reference 13. Typically, floor plate 13 could be rectangular in shape, possibly eight foot by four foot, and provided with a series of six preformed mounting holes in regular distribution throughout its area.

A single mounting location for a blind fastener type fixing device according to the invention is shown in the drawing, and comprises a circular hole 14 defined by a frusto-conical seating shoulder 15 onto which the fixing device can be seated, so as to be housed entirely within the plane of the plate 13.

A fixing device according to the invention is designated generally by reference 16, and is received by the mounting hole 14, and capable of being rotationally adjusted about a vertical axis 17 passing upwardly through the centre of the device.

The fixing device 16 comprises a circular cover plate 18 which is rotatable in the mounting hole 14 about axis 17, for initial assembly purposes as will be described in more detail below.

The cover plate 18 carries a guide 19 which extends downwardly therefrom in a direction generally parallel to the rotational axis 17 of the cover plate 18, the guide 19 being spaced laterally or off-set from axis 17.

In the illustrated embodiment, guide 19 comprises a guide tube formed in one piece with the cover plate 18.

A threaded fastener 20 is provided which can extend downwardly through guide tube 19, and is freely rotatable therein. The fastener 20 has a head 21 which is housed entirely within an enlarged mouth defined at the entrance to guide tube 19, and an internally threaded clamping element or "nut" 22 is fitted on the lower end of the threaded fastener 20.

Clamping element 22 has a laterally projecting formation 23 which is shaped so as to be engageable with and to receive the lower edge of one of the mesh bars, as shown for mesh bar lia shown in Figure 2.

Upon initial assembly of the floor plate 13 to the mesh structure 10, the fixing device 16 is introduced into the mounting hole 14 in such a way that the guide 19, threaded fastener 20 and clamping element 23 can move downwardly through any space available below the mounting hole 14 between adjacent mesh bars. This will be possible by reason of the off-set arrangement of the fastener 20, with suitable manual manipulation of the fixing device.

Thereafter, the second stage of the assembly takes place, whereby the clamping plate 18 is caused to rotate about axis 17 until such time as either the guide 19 and / or clamping element 22 come into engagement with a side face of one of the mesh bars 11, 12. The head 21 of the fastener 20 is then rotated to move an upstanding lug 26 of the clamping element 22 into engagement with the side face of the mesh bar, at which time the formation 23 will underlie the mesh bar and further tightening of the fastener 20 will then draw the clamping element 22 upwardly into clamping engagement with the underside of the mesh bar.Thus, the formation 23 of the clamping element 22 is bought into registry with the lower edge of the particular mesh bar, and the fixing device is then tightened in order to clamp the floor plate 13 to the structure 10, by suitable tightening of the head 21 of the fastener 20.

The fixing device therefore functions as a "blind fastener", whereby all necessary initial manipulation of the device, and final tightening, can take place from above the floor plate 13 to bring the clamping element 22 into engagement with the lower edge of a suitable mesh bar, and followed by final tightening in position.

In the illustrated embodiment, cover plate 18 is rotatable in conical seating 15 provided around the periphery of the mounting hole 14. However, although not shown, cover plate 18 may be arranged to rotate within a mounting portion of the device, such mounting portion being non-rotatably mounted in a suitably shaped mounting hole (not necessary circular) formed in the floor plate.

Rotational adjustment of the cover plate 18 is facilitated, for the purpose of bringing the clamping element 22 into co-operation with any suitable one of the mesh bars, by providing a drive connection which is formed on or in the upper surface of the cover plate. In the illustrated arrangement, this comprises a hexagonal socket 24 which can be engaged by an Allen key.

The clamping element 22, which effectively comprises a specially designed internally threaded "nut", has laterally projecting formation 23 formed by a flange or tongue, and which is provided with an upwardly facing trough-shaped recess 25 formed in its surface onto which the lower edge of mesh bar (11a) can be seated.

To assist the initial locating of an appropriate mesh bar, upon rotational adjustment of cover plate 18, the clamping element 22 is provided with the upstanding lug 26 which is movable into engagement with a side face of the mesh bar proper to be engaged by the clamping element 22, or an immediately adjacent mesh bar, as shown in the illustrated arrangement, wherein lug 26 is fitting snugly against intermediate bar 12 at its junction with one of the bearing bars 11.The fixing device of the invention therefore permits easy and reliable holding down of floor plates to underlying open mesh deck or floor structures, and in a way which enables the assembly to take place from above the floor plate, and with only relatively straight forward minor manipulation so as to cause the clamping components (19, 20, 22) to be manipulated through any space made available below the particular mounting holes, which is then followed by reliable clamping of the assembly together.

Once the fixing device has been fully tightened, assuming it has been correctly positioned and engaged with the underlying mesh bars, cover plate 18 will be securely seated and housed within the plane of the floor plate 13, and will not project therefrom. If it should project i.e.

because it is not seated properly, this will be an immediate visible indication of an improper assembly. However, once properly assembled, no obstruction will be provided to pedestrian traffic, or the slidable or rolling movement of goods over the floor plate. Similarly, the head 21 of the fastener 20 is housed within the plane of the floor plate 13, and also does not provide any obstruction.

Claims (15)

1. A fixing device for holding down a floor plate to an underlying open mesh structure built-up from a number of mesh bars, at least some of which are laterally spaced from each other, said fixing device being receivable by a mounting hole provided in the floor plate and being capable of extending through a space defined between a pair of adjacent mesh bars underlying the mounting hole, and being movable into clamping engagement with one of the mesh bars and upon tightening to hold down the floor plate to the mesh structure, in which the fixing device comprises:: a cover plate which is rotatable in said mounting hole about an axis extending upwardly through the cover plate; a guide carried by the cover plate and extending downwardly therefrom in a direction generally parallel to the rotational axis of the cover plate, said guide being spaced laterally from said axis; -' a threaded fastener to extend downwardly through said guide and being rotatable therein; and, an internally threaded clamping element to be fitted on the lower end of the threaded fastener and having a laterally projecting formation to engage the lower edge of one of the mesh bars, whereby (1) upon initial assembly the guide and threaded fastener can be moved downwardly through any space available below the mounting hole between adjacent mesh bars, (2) thereafter the cover plate is rotatable until the guide and / or the clamping element come into engagement with a side face of one of the mesh bars and so as to bring said formation of the clamping element into registry with the lower edge of the mesh bar, and (3) finally the fastener is tightenable in order to clamp the plate to the mesh structure.

2. A fixing device according to Claim 1, in which the cover plate is rotatable in a seating formed in the mounting hole.

3. A fixing device according to Claim 2,.in which the seating comprises a frusto-conical shoulder onto which a bevelled edge of the cover plate can be seated.

4. A fixing device according to Claim 1, in which the cover plate is rotatable within a mounting portion of the device, said mounting portion being non-rotatably mounted in the mounting hole in the floor plate.

5. A fixing device according to any one of Claims 1 to 4, in which the cover plate has a circular shape, with its axis of rotation passing through the centre of the circle.

6. A fixing device according to any one of Claims 1 to 5, including a drive connection formed on or in the upper surface of the cover plate, to permit rotation adjustment of the cover plate to bring the clamping element into cooperation with any suitable one of the underlying mesh bars.

7. A fixing device according to Claim 6, in which the drive connection comprises a hexagonal socket formed in a central region of the cover plate to be engaged by an Allen key.

8. A fixing device according to any one of the preceding claims, in which the guide is provided with an enlarged mouth into which a head of the fastener can be received, so that the head does not project upwardly from the surface of the cover plate.

9. A fixing device according to Claim 8, in which the cover plate is housed in the mounting hole in such a way that it also does not project upwardly of the surrounding surface of the floor plate.

10. A fixing device according to any one of the preceding claims, in which the clamping element comprises an internally threaded nut, and the laterally projecting formation comprises a flange or tongue having a trough-shaped recess formed in its surface onto which the lower edge of a mesh bar can be seated.

11. A fixing device according to Claim 10, in which the clamping element has an upstanding lug which is movable into engagement with a side face of the mesh bar upon rotation of the fastener, and following the rotational adjustment of the cover plate.

12. A fixing device according to any one of the preceding claims, in which the guide comprises a tube which is rigidly attached to the cover plate.

13. A fixing device according to Claim 12, in which the tube is formed in one piece with the cover plate.

14. A fixing device according to Claim 12 or 13, in which the guide tube permits the threaded fastener to be freely rotatable therein.

15. A fixing device according to Claim 1 and substantially as hereinbefore described with reference to, and as shown in the accompanying drawing.