US3702592A

US3702592A - Fire retardant container

Info

Publication number: US3702592A
Application number: US90727A
Authority: US
Inventors: Edward R Gamble
Original assignee: American Air Filter Co Inc
Current assignee: MILL AND MINE SERVICES Inc A CORP OF; American Air Filter Co Inc
Priority date: 1970-11-18
Filing date: 1970-11-18
Publication date: 1972-11-14
Anticipated expiration: 1989-11-14

Abstract

A fireproof container having an outer housing, an inner housing, and heat protection means disposed between the outer and inner housings. The heat protection means includes an ablative material.

Description

United States Patent Gamble [54] FIRE RETARDANT CONTAINER [72] Inventor: Edward R. Gamble, Clayton, Mo.

[73] Assignee: American Air filter Company, Inc.,

Louisville, Ky.

22 Filed: Nov. 18,1970

21 Appl. No.: 90,727

52 U.S.Cl ..109/29, 220/9 R, 109/84 51 Int. Cl ..E05g 1/00 58 FieldofSearch ..109/29-34, 76,

109/80, 84; 220/9 B, 9 A, 9 LG, 9 R

[ NOV. 14, 1972 Primary Examiner-Dennis L. Taylor Attorney-Charles G. Lamb and Ralph E. Brick [5 7] ABSTRACT A fireproof container having an outer housing, an [56] References Clted inner housing, and heat protection means disposed UNTED STATES PATENTS between the outer and inner housings. The heat protection means includes an ablative material. 1,038,428 9/1912 Pederson ..109/84 2,586,873 2/1952 Siple ..109/84 X 5 Claim, 6 Drawing Figures I 5 9% $i f \7 \g/ 1 7 19 1 ax FIRE RETARDANT CONTAINER BACKGROUND OF THE INVENTION Fireproof containers are well known in the prior art. Most of these containers provide adequate protection for the contents stored therein against destruction by fire but are relatively high in cost, high in weight, and low in usable volume in comparison with the overall dimensions of the container. In recent years there has been considerable activity in reducing the cost and weight of these containers while at the same time increasing the usable volume. Most of the activity has centered around insulations which could be installed between the outer housing or frame of the container and the contents inside which are to be protected. One family of insulations now being used in fireproof containers is the high temperature resistant molded plastic compositions. However, for many applications these fireproof containers have still been found to be too heavy and will not protect the contents of the container at high temperatures for extended periods of time.

SUMMARY OF THE INVENTION In the present invention, it is recognized that it is desirable to provide a fireproof container being low in cost, light in weight, and large in usable volume. Furthermore, it is recognized that it is desirable to provide a fireproof container wherein the contents are adequately protected against the severest conditions of exposure to, for example, burning brush, wood, and tentage.

The present invention advantageously provides a straight forward fireproof container useful for the protection of valuables against the severest conditions of exposure to burning brush, wood, tentage, and the like.

The present invention also provides a fireproof container utilizing ablative materials to protect the contents of the container when exposed to high temperatures for extended periods of time. The ablative materials, as used hereinafter, refer to those materials that are non-combustible and sublimate at elevated temperatures. These materials dissipate energy from heat, such as a fire, with an accompanying loss of material. Many of these materials are utilized in the art of rocketry as heat dissipators for rockets which reenter the earths atmosphere at extremely high velocities. US. Pat. Nos. 3,022,190; 3,395,035; and 3,506,607 describe in detail many of the ablative materials that may be used as heat dissipators in rocket re-entry. These materials have now been found useful in fireproof containers when applied in the manner hereinafter described.

The present invention further provides a fireproof container which is light in weight and economical in cost.

Various other features of the present invention will become obvious to those skilled in the art upon reading the disclosure set forth hereinafter.

More particularly, the present invention provides for a fireproof container comprising: an outer housing; an inner housing disposed within said outer housing in spaced relation therefrom to define a chamber therebetween, said inner housing defining a plenum and having an opening therein; heat protection means disposed in said chamber and extending between said outer housing and said inner housing, said heat protec- LII tion means including an ablative material; vent means adapted for venting gaseous products of said ablative material from said chamber in the event said container is exposed to excessive heat; and closure means adapted to communicate with said inner housing, said closure means including an outer wall and an inner wall with heat protection means disposed therebetween.

It is to be understood that the description of the examples of the present invention given hereinafter are not by way of limitation, and that various modifications with the scope of the present invention will occur to those skilled in the art upon reading the disclosures set forth hereinafter.

FIG. 1 is a perspective view of a container assembly in accordance with the present invention;

FIG. 2 is a perspective view of a container assembly, without the lid, in accordance with the present invention;

FIG. 3 is a vertical sectional view of a container assembly, taken along the line 3-3 of FIG. 2;

FIG. 4 is a partial vertical sectional view of a container assembly, taken along the line 4-4 of FIG. 2;

FIG. 5 is a perspective view of a lid of a container assembly in accordance with the present invention; and,

FIG. 6 is a vertical sectional view of a lid of a container assembly taken along the line 6-6 of FIG. 5.

Referring to FIGS. 1 and 2 of the drawing there is illustrated a lid 10 having a top wall 3 with downwardly extending sides 14. On each downwardly extending side 14 there is provided a latch 4. Lid 10 is further provided with a handle 1 for lifting and removing the lid 10 from the container 20. Vents 2a and 2b are provided for venting ablative gases, hereinafter described, from the container 20 and the lid 10 whenever the container 20 and the lid 10 are exposed to excessive heat.

The container 20 is comprised of an outer housing including outer end walls 7 and outer side walls 9, inner housing 33, and heat protection means, hereinafter described, disposed between and in communicative relation with

outer walls

7 and 9 and inner housing 33. Outer end walls 7 are provided with vertically extending sections 8 and horizontally extending top sections 11 to outer fit side walls 9. Rivets 34 are used to attach sections 8 and 1 1 to walls 9. Fixedly attached to the end walls 7 are upwardly extending latch cases 6 which are positioned to be received by latches 4. The horizontally extending top sections 11 have disposed therein a plurality of vents 13 for venting ablative gases, hereinafter described, from the container 20. Outer side walls 9 are provided with horizontally extending top sections 12 which underfit horizontally extending top sections 11. Fixedly attached to the outer side walls 9 are upwardly extending latch cases 6 which are positioned to be received by latches 4.

Inner housing 33 is comprised of side walls 5, end walls 21, and a bottom wall 32 (FIG. 3).

FIGS. 3 and 4 show one advantageous embodiment of a heat protection means within the scope of the present invention.

FIG. 3 illustrates that the heat protection means disposed between the outer side wall 9 and the inner side wall 5 includes outer ablative material 16, horizontally extending honeycomb material 17, and inner ablative material 19, respectively. Ablative material 16 and ablative material 19 may be the same or different ablative materials. It is also seen in FIG. 3 that the horizontally extending top section 12 of outer side walls 9 and inner side walls are joined by rivets 29. Disposed between and in communicative relation with section 12 and walls 5 is asbestos paper 22.

FIG. 3 further illustrates that the heat protection means disposed between the bottom wall 25 of the container 20 and the bottom wall 32 of the inner housing 33 includes outer ablative 16, vertically extending honeycomb 18, and inner ablative 19, respectively.

In FIG. 4 it is seen that the heat protection means disposed between the outer end wall 7 and the inner housing end wall 21 includes outer ablative material 16, horizontal extending honeycomb 17, and inner ablative material 19, respectively. Horizontally extending top section 11 of outer end wall 7 and inner end wall 21 are joined by rivets 29. Disposed between and in communicative relation with

sections

11 and 21 is asbestos paper 35.

Referring now to the lid as illustrated in FIGS. 5 and 6, it is seen that the heat protection means is disposed between the outer wall 3 and the inner wall 28. The heat protection means includes outer ablative material 23, outer vertically extending honeycomb 24-, inner vertically extending honeycomb 26, and inner ablative material 27, respectively. The outer ablative material 23 and the inner ablative material 27 may be the same or different materials. Outer vertically extending honeycomb 24 and the inner vertically extending honeycomb 26 may be the same or different materials as well as the same or different configurations. Further, since the honeycomb material is primarily used as a support, it is not necessary to have two honeycomb sections, but only one. If only one honeycomb section is used, then the honeycomb will be fabricated to fit the irregular shape of lid 10.

Outer wall 3 is provided with downwardly extending sides 14 and inner wall 28 is provided with Z-shaped upwardly extending sides 15. Disposed between the sides 14 and the sides is asbestos paper 31 and a felted material 30 having high temperature insulative properties. One preferred felted material is a felted material manufactured by Johns-Manville under the trade name, Cerafelt. The felted material 30 is configured to fit the horizontal extending section 36 of the Z-shaped upwardly extending sides 15, the asbestos paper 31, and the downwardly extending sides 14. The felted material 30 communicates with horizontally extending

top sections

11 and 12 of container (FIG. 2) whenever lid 10 is in mating relationship with container 20.

The inner wall 28 with the upwardly extending sides 15 is constructed to fit within the inner housing 33 (FIG. 2) of the container 20 (FIG. 2), the sides 15 being in communication with the side walls 5 and the end walls 21 of the inner housing 33.

In the construction of a fireproof container of the instant invention, variations of the container design, as illustrated in the drawings, can be made to provide any desired internal capacity. The design will be dependent upon, among other things, the volume and weight of the contents to be protected, and the fire hazards that the container may be subjected to. For example, one container which was designed to handle a 30-inch stack of 8% X 11-inch documents and to protect these contents in a fire at l550 F. for 30 minutes with a temperature rise of 350 F. or less, the

outer walls

7, 9, and 25 were fabricated from an l -gauge cold-rolled steel and the inner housing 33 was fabricated from 0.050- inch anodized aluminum. The ablative material used was a composition having a sublimation temperature of about 400 F. This material was obtained from Thermal Systems Inc. and was identified as FP-T22068 Thermo-Lag.

In the choice of ablative materials to be used, it must be determined that at the range of temperatures under which it is to be subjected, it must sublime (change from the solid state to the vapor state) and not simply decompose. In fireproof containers the critical temperature range to which the container may become exposed is from the kindling temperature of the material to be protected, to the maximum normally encountered by fires fed by wood and similar building materials, that is, approximately 200 to l600 F., and the temperature rise of the container contents may be from existing ambient temperature to the kindling point of the material, which will vary from 60 F. to approximately l600 F.

Further, the amount of ablative material required will be that amount sufficient to withstand the anticipated critical temperatures up to 60 minutes while not allowing the temperature of the inside of the container to rise above the aforementioned limits. Thus, if the maximum heat rise of the contents of the container cannot be above, for example, about 400 F, then an ablative composition having a sublimation temperature of about 450 or less would be the proper ablative to use If the contents to be protected can withstand temperatures in the neighborhood of 1000 F., then an ablative having a sublimation temperature of 1050 F. or less would be acceptable. The amount of ablative necessary would depend upon the latent heat of sublimation of the ablative and the total amount of heat such ablative would be exposed to. Some examples of ablative materials that may be used include ammonium fluoroborate which sublimes at about 450 F., molybdenum hexacarbonyl which sublimes at about 230 F., chromium trichloride which sublimes at about 180 F., mercuric sulfide (red) which sublimes at about 1075 F., ammonium chloride which sublimes at about 635 F., and the like.

In preparing a use composition of an ablative it may be necessary to add a binder, such as, for example, a resorcinal-phenol-formaldehyde resin; and accelerator to speed-up the curing of the binder, such as, for example, paraformaldehyde; a heat transferring material, such as, for example, graphite; and a carrier for the ablative with the aforementioned binder, accelerator, and heat transferring material, such as, for example, ethyl alcohol. The use composition may include fillers and other ingredients which are compatible with the ablative material in order to assist in the application of the ablative material in the fireproof container by methods hereinafter described. These compositions containing other materials which assist in preparation of the ablative material into a use composition are within the scope of this invention.

In applying the ablative composition in the fireproof container at the points described in the aforementioned discussion of the drawings, the ablative composition may be poured and troweled or sprayed. In the instant invention pouring and trowelling has been a preferred method of applying.

in one embodiment of fabricating a fireproof container of the instant invention, the

outer walls

7, 9 and 25 of container 20 are constructed and riveted together with rivets 34, the rivets 34 and the

walls

7, 9 and 25 being suitable for the temperature range anticipated. The riveted

outer walls

7, 9 and 25 are then laid on one wall and a predetermined amount of ablative material 16 is poured in and spread uniformly with a trowel. Honeycomb material 17, which is usually a fire-retardant cardboard, is then laid on the ablative and pressed in firmly. The ablative, in addition to its aforementioned properties, acts as a glue or bonding agent. Each of the other walls is done in order, adding the ablative and then pressing in the honeycomb, with the bottom wall 25 being the last to be completed. Ablative material 19 is then added and the inner housing 33 is then lowered into place. Asbestos paper 22 is inserted between inner housing 33 and the horizontally extending

top sections

11 and 12. Inner housing 33 is then riveted with rivets 29 to the horizontally extending top sections 1 1 and 12 of the

outer walls

7 and 9.

Ablative material 19 is not normally required in the practice of the instant invention but is added in the above discussed embodiment in order to increase the strength of the container 20.

Lid is fabricated in a similar fashion as the container 20. That is, outer wall 3 is cut with downwardly extending sides 14 and ablative material 23 is added, uniformly to the underside of wall 3. Honeycomb material 24 is pressed into the ablative material 23. Asbestos paper 31 is then inserted into the space between the honeycomb material 24 and the sides 14. lnner vertically-extending honeycomb material 26 is then inserted in place and ablative material 27 is added. Inner Wall 28 of the lid 10 with upwardly extending sides configured to outer fit the honeycomb 26 with ablative material 27 attached thereto and the honeycomb 24 is then pressed into place. Felt 30, having a high temperature adhesive backing and being cut to fit the sides 15, the asbestos paper 31 and the sides 14, are then pressed firmly into place.

Handle 1, locks 4, and lock cases 6 are added to the lid 10 and the container by any known prior art method.

The above discussion only illustrates one method of practicing the instant invention. By varying the structure of the lid 10 and the container 20 it is possible to fabricate fireproof containers in the form of file boxes, multiple-drawer file cabinets, vaults, and the like. Further, the closure means, such as lid 10, can be provided with hinged as well as removable means, with the hinged or removable means being located on the top as well as the sides. Thus, numerous variations and substitutions may be made without departing from the spirit and scope of my invention and it is to be understood that no limitation is intended with respect to the instant invention, other than as defined by the claims.

What is claimed is:

1. A fireproof container comprising:

an outer housing; an inner housing disposed within said outer housing in spaced relation therefrom to define a chamber therebetween, said inner housing defining a plenum and having an opening therein;

heat protection means disposed in said chamber and extending between said outer housing and said inner housing, said heat protection means including an ablative material; vent means adapted for venting gaseous products of said ablative materials from said chamber in the event said container is exposed to excessive heat; and closure means adapted to communicate with said inner housing, said closure means including an outer wall and an inner wall with heat protection means disposed therebetween.

2. The fireproof container of claim 1 wherein said heat protection means includes a material of honeycomb configuration.

3. The fireproof container of claim 2 wherein said ablative material is disposed between and in communicative relation with said outer housing and said material of honeycomb configuration.

4. The fireproof container of claim 2 wherein said ablative material is disposed in two layers, a first layer being disposed between and in communicative relation with said outer housing and said material of honeycomb configuration and a second layer is disposed between and in communicative relation with said material of honeycomb configuration and said inner housing.

5. The fireproof container of claim 1 wherein said heat protection means of said closure means includes an ablative material and a material of honeycomb configuration wherein said ablative material is disposed between said top wall of said closure means and said material of honeycomb configuration.

Claims

1. A fireproof container comprising: an outer housing; an inner housing disposed within said outer housing in spaced relation therefrom to define a chamber therebetween, said inner housing defining a plenum and having an opening therein; heat protection means disposed in said chamber and extending between said outer housing and said inner housing, said heat protection means including an ablative material; vent means adapted for venting gaseous products of said ablative materials from said chamber in the event said container is exposed to excessive heat; and closure means adapted to communicate with said inner housing, said closure means including an outer wall and an inner wall with heat protection means disposed therebetween.