BACKGROUND OF THE INVENTION Containers for temporarily protecting their contents from damage from external heat sources such as fire are well known. Such containers are said in the art to be "fire-resistant"and typically are rated for integrity over a specific exposure temperature and/or time. Lockable fire-resistant containers are known as fire-resistant "safes"and are widely used for storage of documents, firearms, or other valuables which may be damaged or destroyed by exposure to high temperatures. For example, various models of fire-resistant safes are available from Sentry Group, Rochester, New York 14625 USA.

A stringent fire endurance test is found in Underwriters Laboratories Standard 72, part 1, which requires a container to maintain an internal temperature of less than 350°F while the container is thermally ramped up a prescribed time-temperature curve from room temperature to 1550°F over 30 minutes. Some prior art fire-resistant safes achieve such resistance to fire by having relatively thick walls and large mass. Such a safe is expensive to manufacture, costly to purchase, and cumbersome to transport.

A less stringent but highly useful fire endurance test (referred to herein as "Sentry Self-Test 1") is identical in all respects to UL Standard 72, part 1, except for requiring a maximum exterior temperature of only 1200°F.

What is needed is a fire-resistant safe or cabinet which is inexpensive to manufacture, easy to transport, and meets the requirements of Sentry Self-Test 1.

It is the primary object of the invention to provide an improved fire-resistant safe or cabinet for storage of documents, firearms, or other valuables which is inexpensive to manufacture, easy to transport, and meets the requirements of Sentry Self-Test 1.

SUMMARY OF THE INVENTION The invention is directed to a fire-resistant container for use as a safe. The container is formed of steel and is lined on its inner surface with fire-resistant materials. The preferred fire-resistant materials include mineral-filled paper-faced sheet material, commonly known as"sheetrock,""gypsum board, "or"drywall." Preferably, the sheet material is provided in various standard thicknesses depending upon the location within the container. Preferably, an air space is also provided between the fire-resistant materials and the wall. A front wall of the container is formed with an offset jamb for receiving a safe door having a conventional combination lock controlling a plurality of livebolts which are received behind a flange formed in the jamb. The door is fitted with fire-resistant materials in similar fashion to the container walls, and the locking mechanism has an inner cover formed preferably of magnesium board, and the jamb is gasketed in intumescent material. A fire-resistant container in accordance with the invention meets Sentry Self-Test 1 and is suitable for storage of paper documents, firearms, and other valuables.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features, and advantages of the invention, as well as presently preferred embodiments thereof, will become more apparent from a reading of the following description in connection with the accompanying drawings, in which: FIG. 1 is an isometric view from the front of a fire-resistant container in accordance with the invention; FIG. 2 is an isometric view from the right side and rear of the container shown in FIG. 1, showing the location of a vent hole in the container back; FIG. 3 is an elevational cross-sectional view of a section formed by plane 3-3 in FIG. 1 ; FIG. 4 is an equatorial cross-sectional view of a section formed by plane 4-4 in FIG. 1 ; and FIG. 5 is a detailed view of the jamb and door arrangement shown in circle 5 in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 through 5, a fire-resistant container 10 in accordance with the invention comprises a rectilinear box 12 closed by a door 14 pivotably attached to box 12 by external hinges 16. Box 12 defines an outer wall of the container and is preferably formed of sheet steel, preferably about 3 mm thick. Door 14 is also preferably formed of sheet steel about 3 mm thick. Door 14 is received in an offset jamb 18 formed around the opening of box 12, the jamb being offset to prevent direct ingress of implements to the interior of the box. Door 14 is provided with a conventional combination lock 20 operationally connected to a conventional livebolt array 22 controlled by a central handle 24. Upon rotation of handle 24, livebolts 22 are received conventionally behind, or withdrawn from, a flange 25 formed around jamb 18 (FIG. 5). Door 14 is provided with an inner cover 28 for covering the locking and livebolt mechanisms.

Box 12 comprises a top wall 30, back wall 32, side walls 34, and bottom 36.

All walls and the door are lined along their inner surfaces with a fire-resistant composition 38, preferably a mineral-filled paper-faced sheet material, commonly <BR> <BR> known as"sheetrock, ""gypsum board, "or"drywall."Preferably, the fire-resistant composition 38 is off-spaced from the inner surfaces of the walls by incombustible spacers 44 formed of, for example, 9 mm magnesium oxide board, to provide an insulative air space 46 therebetween. Preferably, the sheet material 38a lining the top 30, back wall 32, side walls 34, and bottom 36 is 0.625 inches thick.

Referring to FIG. 5, a currently preferred configuration 52 is shown in the jamb region of the container. Side wall 34, front wall 54, jamb 18, and flange 25 cooperate to form a structural cove 56 that frames the doorway. Preferably, cove 56 is filled with combinations of composition 38 having thicknesses of 0.375 inches (38b), 0.500 inches (38c), and 0.625 inches (38a). Door 14 is insulated similarly to the walls; however, inner cover 28 preferably is formed of magnesium oxide board similar to the material employed in spacers 44. Door 14 is further provided with an edge 62 formed to conform with jamb 18 which defines a labyrinthine space 64 therebetween. Door gasket 66 disposed on and surrounding the entire edge of door 14 is formed preferably of a sodium silicate intumescent material, for example, PALUSOL P or PALUSOL PM, available from ODICE S. A. Fire Protection. This material can expand, upon

dehydration by heat, to at least five times its original thickness, rapidly filling space 64 with a rigid, non-combustible foam with a high level of thermal insulation and thereafter preventing ingress of flame and smoke into box 12. Alternatively, gasket 66 may be disposed on jamb 18 instead of door edge 62 to equal effect.

Referring to FIGS. 2 and 3, the intumescent material gives off significant amounts of water vapor or steam during intumescence which requires venting to the exterior of the box. Therefore, at least one vent hole 68 preferably is provided in bottom 36 extending from the exterior of the box to the interior 49. Additionally, one or more vent holes 68a may be provided, extending from the exterior of the box through preferably back wall 32 into air space 46, to prevent thermal distortion of the box as the air expands, which holes may be surrounded on the inner surface of back wall 32 by a mineral paper patch (not shown) to help prevent plugging of the hole during exposure to fire.

In operation, when container 10 is exposed to high external temperature, heat conducted through the walls of box 12 is initially absorbed in the outer surface of fire- resistant composition 38. Transmission of heat thereto is retarded by air space 46.

Heat transmitted through the outer surface is initially abosrbed by the core portion of composition 38. Heat penetrating along labyrinthine space 64 is initially absorbed by intumescent gasket 66 which rapidly swells to close space 64, thereby sealing completely the perimeter of door 14 against jamb 18.

Although a fire-resistant container in accordance with the invention may be incapable of meeting the highly-rigorous conditions of UL Standard 72, part 1, the combination of sheetrock insulation, preferably off-spaced by an insulative captive air space, and an intumescent door gasket does permit such a container to meet the less- demanding conditions of Sentry Self-Test 1. Such a container, therefore, can be highly useful in providing inexpensive, light-weight, fire-resistant storage of firearms, documents, and other valuable items susceptible to damage by fire.

The foregoing description of the preferred embodiment of the invention has been presented for the purpose of illustration and description. It is not intended to be exhaustive nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiments may be modified in light of the above teachings. The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to

enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, the foregoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the following claims.