FLOOR PANEL FOR A CONTAINER

Abstract: A bearer-less floor panel for a container particularly a refrigerated container, is provided with a planar underpan (1) and extruded sheet flooring plates (2) located above and spaced from the underpan. The space between the underpan and sheet flooring plates is filled with high density foam (4). Preferably elongate bearer blocks (3) are located between the underpan and the sheet flooring plates to support the plates in spaced relationship therebetween. High density foam support blocks (3) divide the space between the underpan and flooring plates into a plurality of compartments each separately injection filled with high density foam (4) having a density of 80 to 90 kg/m<3>. The underpan is conveniently of stainless steel having a thickness of 1 mm. or less. The underpan is also planar only having recesses to accommodate a shape complementary to the shape of tine tunnels. The flooring panel produced thereby is of sufficient rigidity and support to enable manufacture of a bearer-less flooring panel which is considerably lighter than known bearer-less flooring panels for refrigerated containers in particular.

Description: FLOOR PANEL FOR A COOTAINER This invention relates to a floor panel for a container particularly a refrigerated container. Such containers are usually of an elongate rectangular configuration made of metal and plastics material with standard ISO couplings at each corner of the structure. The containers usually have a length of some 20 or 40 feet (6.09 or 12.19 metres) . One known type of flooring used with these containers coπprises a plurality of bearing members of I or Z shaped cross-section extending across the width of the rectangular floor panel. A steel underpan is fixed above the bearer members whilst the container flooring comprises a plurality of extruded aluminium sheets butt welded together with each sheet having a plurality of closely spaced elongate members of T-shaped cross-section. The space between the underpan and extruded sheet flooring being filled with foam to give the required insulation properties to the floor area of the container. Goods to be stored within the container are located on the elongate flooring members and coolant gases are fed along the spaces between the members to refrigerate the goods within the container. The I-shaped bearer members are closely spaced and are of a sufficient width to receive a tine tunnel therebetween. Two or more such tine tunnels are provided along the length of the container. The disadvantage of flooring having this construction is that it is exceptionally heavy in view of the number of I or Z shaped bearer members. Efforts have been made to overcome this problem by constructing flooring panels without the bearing members. In one known attempt to overcome this problem the steel underpan has a plurality of corrugations extending widthwise of the flooring panel. An elongate timber support is located at each end of the elongate flooring panel and at the centre thereof to support the extruded aluminium flooring. Between the extruded aluminium flooring and the underpan is injected foam having a density of 80 g/m 3 . This bearer-less floor panel is simpler than the above described conventional panel but has the disadvantage that the steel underpan must be corrugated to provide the necessary structural support thus reducing insulation properties of the flooring panel. Alternatively, the insulating properties of the floor may be maintained by setting the corrugated underpan at a lower level, closer to corner costing level, however, this renders the underpan more liable to damage when the container is placed on uneven ground. Furthermore to ensure the required strength is achieved the underpan must be of a thickness of 2mm making the floor panel quite heavy. It is an object of the present invention to provide a bearer-less floor panel for a container in which the weight of the floor panel is substantially reduced and the insulation value is simultaneously increased. Also, the underpan is protected from damage by being located well above the bearing level of the corner castings. According to the present invention there is provided a bearer-less floor panel for a container comprising a substantially planar underpan, extruded sheet flooring plates located above and spaced from said underpan with the space between the underpan and sheet flooring plates being filled with high density foam. In one preferred embodiment of a bearer-less floor panel according to the present invention elongate bearer blocks are located between the underpan and the sheet flooring plates to support the latter in spaced relationship to the underpan. Preferably, the support blocks divide the space between the steel underpan and the extruded sheet flooring plates into a plurality of compartments each separately injection filled with high density foam. Conveniently the support blocks are elongate blocks of high density foam. The underpan is preferably of stainless steel and is spaced from the flooring sheets by a constant amount other than in the region of tine tunnels. Conveniently the underpan is shaped around the tine tunnels with a rectangular recess for receiving complimentary shaped tine tunnels. Surprisingly, the provision of a layer of high density foam of substantially constant thickness sandwiched between flooring sheets and a planar underpan provide a flooring panel of suf icient rigidity and support that enables the thickness of the underpan to be reduced to 1mm or less resulting in a bearer-less flooring panel which is considerably lighter than known bearer-less flooring panels for containers, and refrigerated containers in particular. An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which:- Fig. 1 is a side elevational view of a flooring panel according to the present invention; Fig. 2 is a partial end elevational view of the flooring panel of Fig. 1; and Fig. 3 is an enlarged partial elevational view of the left hand end of the drawing shown in Fig. 2. Referring more specifically to the drawings, Fig. 1 shows a flooring panel which is of an elongate rectangular configuration having a substantially planar underpan 1 above which is located a sheet flooring plate 2. The plate 2 is spaced from the underpan 1 by a plurality of support blocks 3. The space between the underpan and flooring sheets is filled with foam 4. The underpan 1 is substantially planar having recesses 5 for location over tine tunnels (not shown) fixedly mounted between lower side frame members of the container. The underpan 1 is made of muffler grade (3CR12) stainless steel and is 1mm thick. The sheet flooring plate 2 comprises a plurality of extruded sections each having four elongate laterally spaced flooring planks with a T-shaped cross -section being integrally formed with said aluminium sheets, the spacing between the flooring planks allowing the passage of coolant therebetween. A plurality of such sheets are butt-welded together to form a one piece flooring plate. The blocks 3 located between the underpan and the floor are elongate rectangular blocks of 80 Kg J block foam. The blocks 3 extend from one side of the flooring panel to the other and divide the space between the underpan 1 and T-flcoring 2 into a series of compartments which are effectively sealed by the bonding of the blocks to both the underpan and T-floor. Each of the compartments is filled with foam injected into the compartments the foam being polyurethanefoam having a density of 80 to 90 kg.m . A bonding agent (not shown) is used with the foam to ensure a goodbond between the underpan and the T-flcoring 2. The bonding of the blocks 3 to the underpan 1 and T-flcoring plate 2 is effected with an adhesive such as Sifaflex 11 PC. Furthermore, whilst seven foam blocks are shown in Fig. 1 the exact number and location of such blocks is variable but must include at least three, one at each end and one centrally between the ends. The supporting blocks at each end of the flooring panel are preferably of soft wood bonded top and bottom with adhesive to the T- flooring and underpan respectively. A 20 x 4mm slot is provided in the uppermost surface of the softwood. The T-shaped flooring 2 is more clearly shown in Figs. 2 and 3 in which T-shaped elements 6 are shown to be integral with sheets 7, there being four such elements 6 to each extruded sheet which are butt-welded at 8. Foam side edges 9 of the floor panel are vapour sealed whilst at the bottom left hand side of the edge 9 is a locating block 10 of softwood which is adhesively bonded to the underpan and serves for positioning purposes only during the manufacture of a bearer-less floor panel, A metal strip 12 is welded to the undersurface of the side edge of the T-flooring 2 to act as a heat barrier to ensure no foam damage on welding. The manufacture of the bearer-less flooring panel is achieved by placing a stainless steel underpan on the bed of a hydraulic press and then positioning the spacer blocks 3 on the underpan. A pre-butt welded sheet of T-flooring is then located and bonded to the spacer blocks 3 above the underpan 1. The hydraulic press is then brought to bear down upon the T-flooring whilst simultaneously foam is pumped into the compartments defined between the blocks 3. The side edge 9 of each floor panel is formed by pre-shaped molding blocks (not shown) positione on the edge of the underpan. Therefore, there has been described a bearer-less flooring panel for a refrigerated container in which the thickness of the underpan has been reduced by 50 percent with a corresponding saving in weight whilst the insulating properties of the flooring have been greatly improved by the constant thickness of the foam between the underpan and T-flooring which foam also adds to the strength of the flooring. In use the flooring panel is mounted inside a container with the recesses 5 located over tine tunnels fixed in the container and with the edges of the bearer-less flooring located on and welded to a support lip extending inwardly of the container. In the final form of the containe any gaps between the side walls of the container and the flooring panel are filled with foam so as to provide a constant flooring level throughout the container. A preferred form of foam for use with the flooring panel of the present invention is Isofoam DP8113 The foam has a strength of 6.15 to 9.5kg/sq.cm vhich is adequate for the maximum working loads at the edges of the flooring panel. As with conventional containers, the containers according to the present invention are produced from a combination of steel, aluminium and plastics materials.

Claims: CLAIMS : 1. A bearer-less floor panel for a container comprising a substantially planar underpan, extruded sheet flooring plates located above and spaced from said underpan with the space between the underpan 5 and sheet flooring plates being filled with high density foam. 2. A floor panel as claimed in claim 1, including elongate bearer blocks located between the underpan and the sheet flooring plates to support the latter in spaced relationship to the underpan. 10 3. A floor panel as claimed in claim 2, wherein the support blocks divide the space between the steel underpan and the extruded sheet flooring plates into a plurality of compartments each separately injection filled with high density foam. 15 4. A floor panel as claimed in claim 2 or 3, wherein the support blocks are elongate blocks with high density foam. 5. A floor panel as claimed in anyone of the preceeding claims, 20 wherein the underpan is of stainless steel and is spaced from the flooring sheets by a constant amount other than in the region of tine tunnels. 6. A floor panel as claimed in claim 5, wherein the underpan is 25 shaped around the tine tunnels with a rectangular recess for receiving complementary shaped tine tunnels. 307. A floor panel as claimed in anyone of the preceeding claims, wherein the thickness of the underpan is 1 mm. or less. 8. A floor panel as claimed in anyone of the preceeding claims, wherein the high density foam is Isofoam DP8113 having a strength of 6.15 35 to 9.5 kg/sq.ciπ.

Inventors: COLEBROOK DAVID, COLEBROOK, DAVID
Applicants: SEA CONTAINERS LTD
Application year: 1988
Main classification: B65D90
IPC codes: B62D25, B65D88, B65D90