US2552641A - Heat insulated container having foamed plastic insulation - Google Patents

Description

y 1951 w. L. MORRISON 2,552,641

HEAT INSULATED CONTAINER HAVING FOAMED PLASTIC INSULATION F-iled Jan. 12, 1946 fnvenfor" Patented May 15, 1951 UNITED STATES PATENT OFFICE HEAT INSULATED CONTAINER HAVING FOAMED PLASTIC INSULATION 1 Claim.

My invention relates to an improvement in refrigerating containers and methods of making them.

One purpose is to provide a simple and efficient shipping container.

Another purpose is to provide a container with a minimum heat leakage.

Another purpose is to provide an improved closure and closure sealing means for such a container.

Another purpose is to provide an improved method of making containers.

Other purposes will appear from time to time in the course of the specification and claim.

I illustrate the invention more or less diagrammatically in the accompanying drawings where- Figure 1 is a vertical section through a typical container.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to Figure l, I illustrate the container the major feature of which is the employment or provision of a porous insulating mass of sufficient strength to form a container and closure wall. This mass, indicated generally at I, may be of a foaming material which is permitted or caused to harden with a multitude of bubbles or I voids, diagrammatically indicated at 2. The result is a material of substantial resistance to pressure or breakage, which is very light, anda highly eilicient heat insulation. In Figure 1 I illustrate an insulating structure including the bottom mass A and walls B, the bottom and four side walls defining an open topped storage space. The otherwise open top of the space is closed by a top or closure panel of the same material, indicated at C.

In the formation of the device it may be advantageous to provide an outside finish or walls.

Whereas a paint or enamel surface may under some circumstances be satisfactory, or a surface of heat reflective material, such as metal foil, I find it in general advantageous to provide an inner shell of metal having a bottom wall 3 and side walls 4 which terminate at their upper edges as at 5. I may also employ an outer shell having a bottom wall 6 and side walls I terminating at their upper edges as at 8. The space between the upper edges 5 and 8 is preferably bridged by a seal of some material which is flexible and compressible and which is a poor conductor of heat. I illustrate such a seal as at 9. I may for exple form a seal of plastic impregnated fabric with any suitable internal padding or stufiing such as cork. The seal may be cemented in place by any suitable cement and is preferably so formed as to provide a more or less convex upwardly extending portion H3. The closure member may also have an outer wall it with side walls i2 terminating in free edges 63. It may be advantageous, although often unnecessary, to provide also an inner or bottom plate l4 having an outside edge I5 spaced inwardly from the edge I3. As a matter of convenience the edge l5 may be aligned with the side walls 4 and may overlie the edge 5 of said side walls. In the gap between the edges l3 and I5, I may provide an upper sealing pad Hi which may be identical with or have the characteristics of the lower pad 9.

I may employ any suitable means for urging the cover C into closed position. As a matter of convenience I illustrate eyes 20 on the side walls I2 of the cover to which are pivoted links 2! which in turn carry pivoted levers 22, the inner ends 23 of which are adapted to engage with a securing hook or lug 24 secured to the outer face of a side wall 1. The outer portion of the lever 22 serves as a handle and the parts are so proportioned that when the handle 22 is pushed off center it will draw the closure C snugly downwardly against the upper face of the insulation. The result is to force the sealing pads 9 and I6 against each other and compress them, to pro vide a very effective seal. No perceptible amount of air can pass between the inside and the outside of the container. Nor is there any substantial heat leakage, since the pads 9 and 16 are resistant to the passage of heat.

It will be understood, of course, that any suitable securing means may be employed, and that the individual securing means shown, if used, may be employed in any suitable numbers. It is essential that some means be provided for firmly thrusting the cover or closure C into the closed position with sufficient force to compress the opposed sealing pads 9 and it. It will be understood further that any suitable sealing means may be empolyed and that the pads herein shown are illustrative of an efficient solution of the problem.

Whereas I may find it desirable to cast the insulating mass integrally I may form the mass in flat slabs. In that event the bottom wall and l the side walls may be assembled.

It will also be understood that I may find it advantageous to employ the inner and outer shells themselves as a form between which the insulating material may be poured Whi1e it is still in liquid condition. In that event any suitable means may be employed for spacing the shells apart and for holding them in their desired location. Such means are not indicated herein since a wide variety of means are available.

Whereas I have illustrated my invention as applied to a shipping container it will be understood that it may also be applied to insulation of fixed refrigerating equipment or to the insulation of freight cars, airplanes or the like. It will be understood that whereas I have described and shown a practical and operative device and method, nevertheless many changes may be made in size, shape, number and disposition of parts and in detail and order of steps without departing from the spirit of the invention.

It will be realized that whereas I have shown and described an operative device, still many changes in the size, shape, number and disposition of parts may be made without departing materially from the spirit of my inventionand I wish, therefore, that my showing be taken as in a large sense as diagrammatic.

The use and operation of this invention are as follows:

I illustrate a container which is formed of a body of insulating material which defines and surrounds a storage area in which material to be shipped or handled may be enclosed. For example, I illustrate a number of separate bodies or packages 49 which may conveniently be formed to snugly engage each other and the bounding Wall of the storage space. As an available and efficient insulating material I may employ foamed plastic formed of polystyrene and air. This material is, in effect, a mass of bubbles or voids enclosed in thin plastic Walls. Objects formed of it may be made by being poured in the liquid form, under pressure, and allowed torise like bread, I find it efficient, when forming a container, to provide inner and outer walls or skin members whichdefine or surround the space to be filled by the foaming plastic, and I put the entire member into autoclave and subject it to suitable pressure. When the formation of the plastic insulating mass is complete, the device is ready for use, and includes not only the plastic mass itself, but whatever inner and outer Wall or skin or surface member is employed. Thusthe mass itself, and its surface members, are permanently associated while the foaming plastic is taking its final form. Whereas, I have,

illustrated my methodas applied to a simple shipping container, it will be understood that it may be applied to a wide variety of containers or receptacles, including freight cars, truck bodies, and large storing and shipping units.

In Figure 1, I illustrate inner walls 3, 4 and outer walls 6, 1. These may be made of a wide variety of materials, and in a wide variety of gauges. For example, I may employ inner and outer Walls of sheet metal. The metal may be thin, merely strong enough to protect the exterior of the mass of insulation from damage or indentation, or where the member is subjected to heavy use, I may employ walls of substantial thickness and inherent strength. Where extreme lightness is desired, I may use a simple skin of plastic or rubber other than fabric. Where additional insulating effect is desired, I may use metal foil, either in connection with a wall, or by itself. I may employ a simple cloth covering which becomesimpregnated with the plastic as it foams. In other words, I may subject a cloth layer or a cloth wall to the polystyrene, or other plastic, so that it is shaped with it and adheres to it, duringthe completion or formation of the insulating body.

Whereas, in the drawing I have illustrated one type of cover or closure, and an efficient and usable sealing, it Will be understood that any other suitable cover or closure means may be employed, with whatever securing means is desired.

One characteristic of the above-mentioned polystyrene foam is that it tends to adhere to adjacent surfaces which it engages during its formation. I find it desirable to employ this characteristic to cause the plastic foam to adhere to whatever wall or surface member I employ to surround the foam. For example, if I employ a plastic or a fabric outside layer or surrounding Wall or skin, the skin may, in the course of the formation of the foam, be impregnated with the plastic and be adherently connected to the mass of the plastic foam. Where I employ a flexible skin, such as a fabric, I may surround the skin with a high pressure zone, and supply the liquid plastic tothe interior of the skin at a pressure very slightly exceeding the pressure of the surroundingspace or autoclave. The outer skin may be stiffened or supported or suspended, in the autoclave, or it may be inflated or expanded, by the foaming plastic, to its final form. It will be understood that, Where necessary, any suitable outside packing or foams may be employed, to prevent the deformation of the outer skin by the rising and expanding foam.

I claim:

An insulated container comprising a box open at the top, the bottom and side walls of the box being formed of a foamed plastic insulating mass, a thin, tough skin adherent to the 0pposed sides of the mass to form respectively an outer shell and an inner lining for the box, the skin on the outer and inner sides of the Wall terminating at a horizontal plane, and a flexible, resilient, compressible pad bridging the gap between the outer and inner skins and closing the space between them, a removable cover for the container, comprising a foamed plastic insulating mass, an outer skin adhering thereto, the skin extending down on all four sides thereof parallel with the outer skin of the box, an inner skin for the cover adhering to the plastic mass, the area of the skin conforming to the area of the inner portion of the box defined by the inner skin, a flexible, resilient, compressible pad interposed between the outer-wall of the cover and the termination of the inner wall, and means for holding the cover removably in position to close the box and hold the two compressible members together.

WILLARD L. MORRISON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,397,842 Netzel Nov. 22, 1921 1,435,526 Johnston et a1 Nov. 14, 1922 1,570,617 Copeman Jan. 26, 1926 1,752,295 Felix Apr. 1, 1930 1,828,481 Trobridge et al Oct. 20, 1931 1,958,131 Davidson May 8, 1934 2,054,323 Holbrook Sept. 15, 1936 2,054,754 Kellogg Sept. 15, 1936 2,059,801 Lindsay Nov. 3, 1936 2,091,335 Roberts et al Aug. 31, 1937 2,106,840 Gould Feb. 1, 1938 2,121,052 Roberts et al June 21, 1938 2,147,886 Devine Feb. 21, 1939 2,206,757 Talalay July 2, 1940 2,216,785 Roberts Oct. 8, 1940 2,216,830 Roberts Oct. 8, 1940 2,256,206 Knight Sept. 16, 1941 2,278,441 Harrison et al Apr. 7, 1942 2,308,970 Carter Jan. 19, 1943 2,358,962 Cunningham Sept. 26, 1944 FOREIGN PATENTS Number Country Date 454,933 Great Britain Oct. 6, 1936

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