AU694759B2 - Assembly and method for protecting solid surface materials from thermally induced degradation - Google Patents

Description

VP

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

ri oo o ~oro~o

I

Name of Applicant: Actual Inventor: Address for Service: ossJ ia CSR LIM TED' -es o, Tr. W\ Leslie John Irwin H.R. HODGKINSON CO.

Patent Trade Mark Attorneys Level 3, 20 Alfred Street MILSONS POINT NSW 2061 ASSEMBLY AND METHOD FOR PROTECTING SOLID SURFACE MATERIALS FROM THERMALLY INDUCED DEGRADATION Invention Title: 11 t Details of Associated Provisional Applications: Nos: PM 5148 filed on 18 April 1994, and PM8899 filed on and 19 October 1994 The following statement is a full description of this invention, including the best method of performing it known to us: -qw' ASSEMBLY AND METHOD FOR PROTECTING SOLID SURFACE MATERIALS FROM THERMALLY INDUCED DEGRADATION The present invention relates to an assembly and method for protecting solid surface materials such as are used in kitchens and in commercial food warming against thermally induced degradation.

Solid surface materials are manufactured from plastics material and sold by their manufacturers in slabs or sheet boards. In Australia such materials are marketed under one or mote of at least the following registered trade marks: CORIAN, AZTEQUE, MARBLO, SURELL, and HYTEX. To date such materials have not found wide market acceptance and the majority of kitchen benches, and like work surfaces, are formed from laminate material which is glued or otherwise adhered to some substrates such as particle board. The best known of these laminate materials is that sold under the registered trade mark FORMICA.

In the construction of kitchen benches, it is necessary for the benches to be fabricated in a factory and transported to the kitchen site in manageable sized pieces where a final assembly takes place. With kitchen benches formed from laminate material, the various portions of the kitchen bench are clamped together.

One problem which arises with solid surface materials is that they do not conduct heat well.

In particular, bench top cooking installations which include hot plates sometimes present a problem due to cracking of the solid surface material as a result of the heat generated within the hot plates. This is a particular problem with hot plates of Continental European origin since the mains supply voltage in Continental Europe is 220V whereas in Australia the mains supply voltage is 240V and the small increase in available voltage results in an increase in the heat emitted by such hot plates. In adczion in Continental Europe ambient temperatures are generally lower. The transfer of the heat emitted from the hot plates through the solid surface material can cause localised cracking near the opening in the solid surface material in which the heat source is located. This is unsightly and eventually leads to compromise to the structural integrity of the solid surface material.

Y

The present invention seeks to ameliorate or overcome the problem of unwanted transfer of heat into the solid surface material from the heat source to thereby eliminate heat induced degradation of the solid surface material by such phenomena as crackldng or crazing.

In one broad form the present invention comprises; a method of transferring heat from a slab of solid surface material having a planar upper surface and into which a source of heat is mounted within an opening formed in said slab, said method comprising the steps of: 10 a) forming a groove in the undersurface of said slab, said groove not extending to said upper surface and being spaced about or at a short distance from said opening and following the periphery of said opening for at least a part thereof; b) inserting a heat conductive member into part of or the full length of said groove with a greater part of said heat conductive member being located exterior of said slab; and c) retaining the lesser part of said heat conductive member within said groove and in thermal contact with said solid surface material.

In another form the invention comprises; an assembly for supporting a heat source, said assembly comprising; S 20 a slab of solid surface material having a planar upper surface defining an opening adapted to receive said heat source, the lower surface of said slab defining a groove not extending to said upper surface and which extends around the periphery of the opening for at least a part thereof, and a heat conductive member fixed within said groove and protruding downwards below said lower surface of said slab, said heat conducting member being in thermal contact with said solid surface material so as to remove heat therefrom when said heat source causes heating of the solid surface material.

According to a preferred embodiment, the conductive member downwardly depends from the groove to provide a heat drop in which thermal energy is transferred from the solid surface material to the heat conductive material.

The present invention will now be described in more detail according to a preferred, but non limiting embodiment and with reference to the accompanying illustrations wherein; Fig 1: illustrates a plan view of a typical distribution of the heat cracks which can arise in solid surface material due to the prior art method of installation of hot plates; Fig 2: is a cross sectional view along the lines VIII-VIII of Fig. 1; Fig 3: is a view similar to Fig. 2 but illustrating a preferred embodiment of the method of transferring heat in accordance with the present invention; S :Referring to figure 1 there is shown a plan view of a segment of a solid surface material 1 having an opening 4 (see figure 2) into which is placed a heat source 2 such as a convzntional hot plate. Formed about the periphery of the hot plate are typical crack arrays 3 which are induced by thermal stresses in the solid surface material. The heat cracks 3 are generated in the solid surface material, generally at the corners of the opening 4 formed in the bench top and which receives hot plate 2. Figure 2 shows a cross sectional view of figure 1 taken along lines VIII VIII. As indicated in Fig. 2 there is normally only a very small gap 6 between the a,, hot plate 2 and the edge of the bench top 5. Gap 6 is normally covered by means of a cover strip 7 or other form of sealing. Some insulation which acts as a seal 7a is also often placed .aaoO 20 between the surface 5a of bench 5 and underside surface 2a of hot plate 2.

The problem with the formation of heat cracks is particularly severe where the hot plate 28 is of Contirental European origin and is therefore designed for a voltage supply of 220V which is less than that of the Australian supply voltage which is 240V. The problem is further exacerbated by the fact that generally speaking ambient temperatures are higher in Australia than in Continental Europe.

Once hot plate 2 has reached cooking temperature radiant heat is transferred through the metallic components of the plate thence into the solid surface material either through the top surface of the bench 5 (particularly if the seal 7a between the underside surface 2a of the hot plate and bench 5 is poorly installed or manufactured) or through the face 8 which bounds opening 4.

In accordance with one embodiment of the present invention, the problem of heat cracks appearing in a bench top brought about by the hot plate 2 of Figs 1 and 2 is able to be cured utilising the assembly and method illustrated in Fig. 3 which shows a cross sectional view of a solid surface material into which is placed a hot plate. Here the hot plate 2 is as before, being set into an opening 4 in the bench top 5. The small gap 6 between the bench top 5 and the hot plate 2 is as before save that attempts to insulate the solid surface material of the bench 10 top 5 by means of insulation and media sealing installed in the gap 6 can be omitted, if desired.

According to the invention, the heat generated in the hot plate 2 is encouraged away from the solid surface material and into a conductor 11 which according to one embodiment is attached to bench 5 in the following way. A groove 10 which may have a square, rectangular or rounded profile is cut around the opening 4 and spaced a small distance therefrom. Thus, in an inverted plan view (not illustrated) the groove 10 would define a rectangular path and thus ideally follow the periphery of the hot plate 2 and opening 4. Into the groove 10 is inserted the upper edge 11 a of a heat conductive element 11 which comprises a heat S 20 conductive curtain and is preferably formed from woven mesh such as brass fly screen mesh.

The heat conductive material used may also comprise a metallic sheet. Curtain 11 is retained in the position illustrated in Fig. 3 by means of epoxy resin 12 or similar packaging material which holds the curtain 11 against the hot plate side of the groove 10 i.e. against surface 1 la.

In this way, heat which is transmitted from the hot plate 2 and enters into the material of the bench top 5 is absorbed by the upper edge of the curtain 11 and transmitted into the downwardly depending portion of curtain 11 which forms the greater part of the wire mesh or sheet material. As a consequence, heat is conducted safely away from the bench top 5 and cracking thereof is thereby avoided. The conductor having a greater capacity to conduct heat than the solid surface material acts as a heat sink into which excess heat absorbed by the solid surface material travels thereby reducing the temperature of the solid surface material and hence the cracking and the occurrence of other damaging effects which emerge from overheating.

The foregoing describes only one embodiment of the present invention, and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.

If desired the epoxy resin 12 can be strengthened with glass or carbon fibres and the gauze of curtain 11 can be fabricated from aluminium or copper or similar good heat conductor. A metal foil or plate could also be used.

I

Claims (13)

1. A method of transferring heat from a slab of solid surface material having a planar upper surface and into which a source of heat is mounted within an opening formed in said slab, said method comprising the steps of; a) forming a groove in the undersurface of said slab, said groove not extending to said upper surface and being spaced about or at a short distance from said opening and following the periphery of said opening for at least a part thereof; b) inserting a heat conductive member into part of or the full length of said groove with a greater part of said heat conductive member being located exterior of said slab; and c) retaining the lesser part of said heat conductive member within said groove and in thermal contact wihi said solid surface material.

2. A method according to claim 1 wherein the heat conductive material provides a heat sink for heat generated at or near the opening of the solid surface material by the heat source. 0

3. A method according to claim 2 wherein the groove substantially follows the periphery of the opening for a substantial part ofthe overall length of the periphery.

4. A method according to claim 3 wherein the groove is substantially parallel to or equidistant from the edge or edges of the opening.

A method according to claim 4 wherein the heat conductive member passes around the full length of the opening.

6. A method according to claim 5 wherein the heat conductive member comprises a metallic strip.

7. A method according to claim (6 wherein the width of the metallic strip is less than its length.

8. A method according to claim 7 wherein a substantial portion of the width of the strip downwardly depends in space from the groove.

9. An assembly for dissipating thermal energy induced in a solid surface material by a heat suu;e, the assembly comprising a heat source in a slab of solid surface material having a planar upper surface defining an opening adapted to receive said heat source, the lower surface of said slab defining a groove which extends around the periphery of the opening for at least a part thereof, and a heat conductive member fixed within said groove and protruding downwards below said lower surface of said slab, said heat conducting member being in thermal contact with said solid surface material so as to remove heat therefrom when said heat source causes heating of the solid surface material.

A method according to claim 8 wherein the heat conducting member is either wire mesh or metallic plate.

11. An assembly according to claim 9 wherein the heat conducting member is either wire mesh or metallic plate.

12. A method as hereinbefore described and with reference to the accompanying illustrations.

13. An assembly as hereinbefore described and with reference to the accompanying *illustrations. @,NSTI DATED this 18th day of April, 1995. By:~ IsPatent Atre s 8 IpllllllRdWY i(-BL*IP~ 14_Y. ABSTRACT A method of transferring heat from a slab of solid surface material having a planar upper surface and into which a source of heat is mounted within an opening formed in said slab, said method comprising the steps of; a) forming a groove in the undersurface of said slab, said groove not extending to said upper surface and being spaced about or at a short distance from said opening and following the periphery of said opening for at least a part thereof, b) inserting a heat conductive member into part of or the full length of said groove with So oa greater part of said heat conductive member being located exterior of said slab; and i c) retaining the lesser part of said heat conductive member within said groove and in thermal contact with said solid surface material. o b' o" o "D o r