BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to passive fire fighting apparatus, particularly, but not exclusively, for a helicopter deck.

Description of the Related Art

A helicopter deck was proposed in U.S. Patent No. 4,836,472 to Sutter et al. which makes use of a passive fire fighting system. This is shown in Figure 1 in which extruded aluminum beams 20 on a base 12, 14 support an upper platform 50 for supporting a helicopter. The support beams provide a space between the base and the upper platform. The upper platform is a grating 50 which permits fuel to pass through it. A support beam supports batts 54 of thin, spaced strips of high-heat conductive material 55 below the upper platform. The support beams also support deck plate 58 below and spaced from the batts. The material of the batts conduct localized heat from one- location of a batt to a more even, lower temperature spread generally through the batts. The deck plates catch fuel that pass through the batts and slope to cause the fuel to flow away from the deck.

It is a disadvantage of the helicopter deck of the prior art that it requires construction in-situ, which causes assembly difficulties particularly in a hostile environment, for example on an oil rig and also is expensive, requiring skilled workers to be sent on site to construct the deck.

SUMMARY OF THF. INVENTION

It is an object of the invention to provide an improved helicopter deck passive fire fighting system with

more general application to other industrial uses.

According to the invention in the first aspect, a passive fire fighting apparatus is provided comprising a grating member having a plurality of channels extending 5 therefrom, each channel containing spaced apart layers of heat conductive material for permitting liquid to pass there through and for conducting localized heat from one location of the material to a more even, lower temperature spread generally through the material, and a basin for

10 catching liquid that passes through the material.

Preferably, the grating member and the basin are formed as separate extrusions, the basin having a plurality of channels corresponding to the channels of the grating member and the extrusions being connected together to form

15. a single unit that may be transported on site in the form of planking and assembled.

According to the invention in the second aspect, a passive fire fighting function is provided with planking which comprises a first extrusion having a grating surface

20 and a plurality of channels extending therefrom, each channel containing spaced apart layers of heat conductive material for permitting liquid passing through the grating surface to pass through the material and for conducting localized heat from one location to a more even, lower

25 temperature spread generally through the material, and a second extrusion for catching liquid that passes through the material, the first and second extrusions being con¬ nected together.

Embodiments of the invention will now be described by

30 way of example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a helicopter deck including passive fire fighting apparatus of the prior 35 art.

FIG. 2 is a sectional view of the first embodiment of the invention.

FIG. 3 is a sectional perspective view of a second embodiment of the invention. FIG. 4 is a sectional view illustrating means for connecting extrusions of the embodiments of the invention together.

DETAILED DESCRIPTION OF THE INVENTION With reference to Figs. 2 and 3, first and second embodiments of passive fire fighting apparatus of the invention are shown. The embodiments differ from the prior art shown in Fig. 1 in that the grating and the structure for containing the heat-dissipating material are formed as a single extrusion, with a drainage basin being formed as a second extrusion connected to the first to provide a single unit.

With reference to Fig. 2, a first extrusion 100 includes a surface having a plurality of stamped openings 120 together forming a grating 110. A plurality of limbs 130 extend from the grating 110, the limbs forming five channels 140 there between. The channels are filled with a heat dissipating material 135, for example a material sold under the trademark EXPLOFOIL which is made of a very thin foil aluminum alloy that is slit and expanded to form webs of hexagonally-shaped openings and which is then layered to form an open-cell batt, as disclosed in U.S. Patent No. 4,836,472 to Sutter et al. , the contents of which are incorporated herein by reference. The channels 140 are capped with a porous layer of aluminum foil 150 of thicker construction than material 135 to hold the material 135 in place in the channels.

A second extrusion 160 forms a basin or drainage region having a base 170 and a plurality of limbs 180 (which are complementary to the limbs 130 of the first

extrusion) and which form channels 185 there between.

The free ends of the limbs of 130, 180 of the first and second extrusions are preferably provided with complementary tongue and groove locating elements 200. The extrusions 100, 160 are connected permanently together by application of suitable heat-resistant bonding materials between elements 200 and by welding along the longitudinal external edges 210, 220.

The width W of the planking is preferably about 300 mm, the length being determined by the extrusion process.

A second embodiment of the invention is shown in Fig. 3 which is substantially the same as the embodiment of Fig. 2 except that only three channels containing the material 140 are provided, of reduced depth. Once the extrusions 100, 160 have been secured together, a single unit 500 is formed which can be assembled at the manufacturing plant and transported on site for assembly in the manner of ordinary extruded planking. The method of connection of the planking units of the embodiments of Figs. 2 or 3 is illustrated with reference to Fig. 4, by which support structures such as helicopter landing pads or walkways may be formed.

Each first extrusion 100 is provided on opposed longitudinal sides with one element of a tooth and claw connector 300, 310, the elements of adjacent units interlocking as shown in Fig. 4. The second extrusion 160 is provided with longitudinal extending lips 320, 330, with lip 320 being raised slightly so as not to conflict with lip 330 when assembled. The lips include openings 325, 335 for receiving a bolt 340. Opening 325 is tapped for receiving the bolt 340 directly in threaded engagement.

The bolts are also received by openings 355 in the structure 350 to which the passive fire fighting apparatus is to be attached. The units 500 may be connected together to form a deck

or support structure of the required size. When assembled, the drainage regions lead to a gutter (not shown) for safe disposal of any fuel and preferably, the deck is slanted at an angle to enable fuel in the drainage area to drain into the gutter. Ignition of the fuel is suppressed by the heat dissipating material 135 in the manner disclosed in U.S. Patent No. 4,836,472 to Sutter et al .

While the invention has been described with reference to passive fire fighting apparatus forming a helicopter landing deck, this is not to be construed as limitative and the apparatus may be used for other industrial applications, for example to form walkways of other support structures .