US2556418A - Thermally insulated container and pallet - Google Patents

Description

June l2, 1951 B, E, DEL MAR 2,556,418

THERMALLY INSULATED CONTAINER AND PLLET Fi1ed oct. 1'7, 1949 2 sheets-Sheet 1 June 12, 1951 B, E. DEL MAR l 2,556,418

THERMALLY INSULATED CONTAINER AND PALLET Filed Oct. 17, 1949 2 Sheets-Sheet 2 IN VEN TOR.

v4 fraz/Miy- Patented June 12, 1951 THERMALLY IN SULATED CONTAINER AND PALLET Bruce E. Del Mar, Los Angeles, Calif., assigner to Douglas Aircraft Company, Inc., Santa Monica,

Calif.

Application `October 17, 1949, Serial No. 121,818

16 Claims.

This invention relates to the packaging and preservation of perishables, particularly for transportation thereof over long distances and to the preservation of same during handling and storage.

When such goods are transported overland, as by railways or in motor trucks, it is customarily necessary to house them in refrigerated, humidi- Iied or humid, heavily insulated compartments which must, at considerable expense, be maintained refrigerated during transit. All the articles in such a compartment must be entirely ofI this nature, not susceptible to the detrimental influences of frigidity and humidity, and cannot include a commingling of refrigerated and humidified perishables with goods apt to ber damaged by cold and moisture, for example, ferrous articles.

. Individual insulated containers for perishable goods have hitherto been proposed for obviating continuously refrigerated compartments and enabling carrying mixed cargos in the same 'enclosure or compartment, but they ordinarily require the use of brine or other liquid refrigerant, which is continuously circulated at a costly rate ofkpower and refrigerant consumption; areuneconomically heavy due to the Weight of refrigerrant and refrigerant containing and circulating means; and are of a rigid nature and fixed size and hence do not permit variation of the ratio of outhaul capacity or load to backhaul load capacity. They furthermore cannot be left standing for any appreciable length of time on either the loading or the unloading dock Without serious injury to the perishables because of the imperfect thermal insulation provided thereby; and will not absorb the repeated heavy impacts occurring during the careless handling such containers receive, to protect the fragile perishable contents from damage. Because of their xed size and rigid sha-pe, the single layer level which can be built up on the floor of a compartment with these containers is limited strictly by the height of the cargo door, since these containers cannot be collapsed or varied in volume or shape.

My invention provides a thermally insulated, pre-coolable light weight, low-heat level holding, variable volume, collapsible and disassemblable container of a rugged, simple and relatively inexpensive nature, which to a large degree obviates all the aforesaid defects in prior perishable-containers. Its insulated construction. and precooling and perishable-preserving means are such as to permit safely transporting perishables in completely uninsulated compartments entirely lacking refrigeratng and humidifying provisions.

The container is pre-cooled just before transit and this refrigeration is maintained during transit and delivery by the construction of the container itself, thus obviating the current conventional apparatus for continuously applying refrigerant throughout transit and delivery. In the case of aircraft transports at least, the present invention enables perishables to be more cheaply transported in preserved condition relatively great distances without any consequential or material deterioration in the nature or appearance of the perishables so that their salability at their point of destination Will be substantially the same so far as their condition is concerned as at their point of origin.

By the same token, the container enables mixed cargos of perishables and non-perishables to be carried in one and the same compartment which may therefore remain unrefrigerated and uninsulated and occupied by dry unhumidied air, thereby precluding any possibility of damage to rustable or crackable goods such as machinery, instruments, etc., made principally of metallic materials, as well as preventing moisture damage to such materials as textiles, mail matter, etc.

By virtue of its collapsible construction, it permits the ratio of the outhaul containers to the backhaul containers to be varied so that the same carrier can be used in both directions of transit inasmuch as it can go outbound in a full condition and return in an empty or partially empty condition ready to be filled on the succeeding outhaul. By the same token it can be employed to carry partial orders either way. Thus, only the one size or dimensional nature of container need be built; that size being the maximum receivable in railway or motor truck or airplane cargo compartments.

Its novel constructionof thermal insulating means, precooling means and airtight nature enable it to be left standing on the docks Without possibility of damage to the perishable containers for sufficient lengths of time to easily coordinate the traflic handling of trucks meeting aircraft at the dock without actually delaying truck schedules to exactly coincide with aircraft schedules which often are delayed because of uncontrollable influences. Since substantially all of the elements of the container are rugged and durable, although put together in a novel manner to enable collapsing and disassembling,

the perishables can be loaded directly into the container for transport therein through every stage of transit including the quite careless and rough treatment often received in bringing them to the railway line, the motor truck or the airplane from the farm, the produce market, or the storage Vplane in light, poorly balanced and sprung trucks. Thus, there is eliminated the necessity for first loading the individual crates or separate perishable items into a container built to withstand this excessively hard handling, followed by transfer thereof into the container to be used for the transit in the railway car, motor truck, or airplane.

Because the container can be partially filled before it is inserted through the cargo door, filling being completed when the container rests on the cargo floor or deck, this being accomplished in one form of the invention through an access flap in the container constructed nonetheless to maintain insulating integrity, the single layer level of cargo achievable within the compartment by means of this container is not restricted as heretofore by the height of the cargo door, being limited only by the height and extensibility of the container. Since the container is composed of separable parts, it may be disassembled at its destination if no return load therefor is available, whereafter it can be stowed in comparatively, eX- ceptionally small compass in the compartment, thereby to render available on the cargo floor, space that can be used for payload other than the perishables unavailable at this end of the run.

The other concepts, aims, and accomplishments, as well as many other novel features of the invention will either be made manifest or become apparent hereinafter.

Solely for the purposes of further clarifying the inventive concepts and of enabling at least one form of the invention to be reproduced herefrom, Y

one of the presently preferred structural forms of the inventive concepts is shown, by way of example only, in the accompanying drawings and described hereinafter by reference to and in conjunction with these drawings. It is to be understood that the inventive concepts and principles are limited only to those which are configurationally set forth in the annexed claims, and the ambit of the patent is to be limited only by the scope of these claims interpreted in the light of the drawing and description.

In these drawings, Figure l is a perspective of the article in its extended condition ready to be completely or partially loaded and inserted in the transport compartment of either improved or unimproved nature;

Figure 2, which is an enlarged fragmentary detailed sectional view taken transversely of one corner of the container to show the details of construction of the pallet, the precooling inlet and the construction of the rigid bottom of the container;

Figure 3 is a vertical cross-section taken on line 3 3 to show the internal construction of the container lining or retainer member, the container being shown in both the extended and the partially collapsed conditions;

Figure 4 is a fragmentary, enlarged detail of the top portion of the section taken on line 3 3 of Figure l to illustrate the construction of the refrigerant vent valve or relief valve;

Figure 5 is a longitudinal view of the combined corner post and refrigerant distributing conduit;

Figure 6 is a horizontal sectional view of the container along line 6-6 of Figure l sighting in the direction of the arrows;

Y hereinafter particularized.

Figure '7 is an enlarged longitudinal, sectional view taken on line 1-1 of Figure l and sighting in the direction of the arrows to show the construction of the tiedown members of the container, and;

Figure 8 is a perspective of the container with its parts disassembled and packed together in small compass to enable stowage thereof in a storeroom or other space in the aircraft not used for cargo transport so that when no perishables are available for transport the container space may be employed for cargo other than perishables.

The exemplifying embodiment illustrated in the aforedescribed drawings essentially includes the following principal elements broadly summarized: rst, a pallet or double base lil dually functioning as the vertical-load taking member or rigid bottom of the container and as a liftmember or open framework into which the prongs of a lift truck can be easily inserted and securely held. It further includes a plurality of vertical, telescopable corner posts Il, each carried by one of the four corners of the base and outlining and defining the vertical edges of the container. A flexible, tough, and resistant reticulate retainer member l2 lines the container and is carried by loops I2a thereon loosely encircling the adjacent corner posts in a plurality of vertically spaced stations. The member l2 serves to take all lateral thrust and loads emanating from the shiftable contents of the container. Fluid admitting and conducting means I3, here shown as combined or integral with but one of the corner posts, are provided to entrain a gaseous refrigerant into the container. Valve means i4 is provided for relieving excess refrigerant pressure or to vent any heated refrigerant or warm air rising to the top of the container. A substantially iiexible and collapsible, substantially airtight, thermally insulated cover l5, here shown as a cap or dome-member, is fitted down around the outside of all the aforestated members and isi detachably secured at all its lower peripheral edges to the subadjacent edges of the load base Il. Means i6,

` here shown as substantially conventional bolts,

but of any suitable nature desired, are provided and engaged with the base l1 and the floor for releasably anchoring the container to the floor of the cargo compartment in an improved manner Certain important and useful adjuncts, hereinafter described in detail, are also provided but the basic objects and accomplishments of the invention maybe achieved by an suitable design including only the aforestated essential components.

The bottom or base unit l of the container dually constitutes at one and the same time both a pallet or handling member and a rigid container-bottom, and comprises an upper component or load plate il and a lower componentv or foot iii. The component I1 in the embodiment herein selected for illustrative purposes consists essentially of a single piece of a well known type of sandwich board structural material and here shown as made up of a paper honeycomb I9 laminated on its opposite faces with fibrous or wooden veneer facing sheets 2 as by a phenolic resin or the like. Thereby is provided a "thermally non-conducting, thermally impenetrable, substantially rigid, force-resisting load base of an improved nature. This member I 1 is spaced ver` tically from the member i8 at various points of the peripheral regions of both members by short, hollow,iianged tubular spacers or compression members 2I, which if desired, can be made of any material having suiiicient compressive strength to resist the anticipated loads to be laid on the member II. A nipple 2m of thermal insulating material, such as Bakelite, or the like, is screwed at its lower end into the upper end of each of the tubular members 2l and extends upwardly substantially airtightly through suitable apertures in the corner regions of member I 'I. The upper end of each nipple 2id is provided with threads to enable it to engage certain socket members 25, later described. By this construction, no rivets, Screws or other heat conductors capable of providing a heat path into the interior of the container are employed, the members 2l and 25 instead being clamped in this configurationv to the base member II and engaging only the member I'l and only through the insulating nipple 2Ia. In the present embodiment it is preferred that members 2i be constructed of a suitable metal.

The member I8 is made up as a rectangular reticulate framework from a plurality of inverted metallic channels 22 united by a metallic plate 23 provided with lightening holes, not shown. Scuff plates 2li are united in facewise contact with both the opposite faces of the base member I1. The upper plate 24 serves to prevent the sandwich board bottom of the container from being damaged no matter how long it is used, relieving it of all abrasion, penetration, dents, and the like and the lower scuff plate functions to take the abrasion and impacts of the liftprongs of the lift truck.

Detachably mountedat each of the four corners of the rigid bottom member of the container, as by socket members 25 and detachable pins 26, are the four Vtelescopable corner posts II. Each post is comprised of two hollow concentric tubular members 2'! and 28 mounted in mutually axially, slidable relationship. The inner, upper one of the two tubular members of each post is inwardly recurved at its upper end, which end is tapered to a small central opening designed to emit a stream of pressurized frigid air or other frigid gas for the application of the initial and s'ole-refrigerating mass for they container. This member, and the lower outer member also is pro"- videdat a series of vertically spaced stations with a circumferentially spaced series of apertures 29, all capable of discharging a pressurized refrigerating gas. A removable lock pin 30 may be provided in the lower one of the tubular members and extends through both tubes in such manner as to maintainrthem in any desired vertically adjusted relationship.

The reticulate, flexible framework or lining I2,

rconstituting the chief lateral load-taking member of the container, is constructed of a plurality of straps 3i mutually rectangularly disposed and united at their intersections. The retainer thereby formed is suspended by its uppermost straps from the adjacent recurved portions of the corner posts. The lower courses of the retainer are engaged with the adjacent corner posts by means of loops I 2a formed integral with the courses at the corners thereof. The retainer I2 has a vertical dimension sufficient to extend from in a plurality of vertically separated rows and each hook is adapted to engage securely but releasably a corresponding one of a plurality of hook-eyes 33 or the like, attached to the subadjacent region of the upper face of the load base I'I. The catches of successive courses on the lining I2 are adapted to successively come down into engagement with the eyes 33, in vertical succession as the container is collapsed, and as the lower portion of the lining I2 is folded under and inwardly, the loops I2a slipping down the corner posts to new positions.

The flexible and tensilely resistant lining I2, being anchored at its top and bottom terminals and being supported laterally and vertically at each corner post, serves well to maintain crated perishables in their original stacked arrangement, preventing any lateral shifting thereof and is also capable of serving as a binder to bundle loose perishable items into a relatively tight, secure and substantially unitary package. Additional straps may be passed across the top of the space and connected to straps 3l to resist any vertical displacement of the load.

At one of the corners of the pallet, the spacer 2| is formed with a suitable nipple or fitting 35 of any suitable nature for attachment thereto of a frigid air hose or other frigid air conduit. Air or other gas entering nipple 35 is entrained upwardly in the corner post and emerges from the vertically spaced series of outlets 29, the end flow emerging from the hole in the gooseneck at the .uppermost end of the combined corner post and refrigerating conduit.

Over and outside all the parts lying above the baseboard lits the aforementioned thermally insulated, iiexible, hermetically sealed cap or cover l5. The member I5 is preferably constructed of three layers or laminae, the two outermost layers 3S consisting preferably of a strong, wear-resistant but flexible material such as a canvas tarpaulin or the like. The intermediate layer 37 comprises a blanket consisting of iberglas bonded on both faces with a polyvinyl, preferably the chloride form thereof, the canvas sheets being quiltedly sewn together through the fiberglas to form a unitary sheet. Although the cap may be formed from the one continuous sheet shaped thereafter to the concave form shown, it is preferable that it be constructed of separate segments or gores united along adjacent edges, as shown. This type of construction facilitates manufacture and enables the cap to be conformed more readily to the outline of the container and its contents and to be more easily fitted and removed. The cap l5 is detachably secured at its lower peripheral edgesto the subadjacent edges of the load plate Ii by means enabling easy and rapid engagement and disengagement of these two components and thus preferably includes a flap slide fastener 38, such as those manufactured by the B. F. Goodrich Company and commonly ways: the load may be stacked on the load plate I2 before applying the cap, after which the cap may be fitted over .and pulled down around it, which is preferable when' a large number of bulky, heavy crates are employed; or, on Vthe Arailway freight cars.

other hand, when the load consists of separate smaller items, these may be successively inserted into the assembled container through a loading iiap 39 formed in one face and the adjacent ends thereof and securable to the adjacent edges of the cap by means of suitable slide fasteners.

Venting means for relieving over-pressure conditions in the container caused by admitting an excessive amount oi' reirigerating gas or due to the gaseous contents becoming heated and rising, are provided and are located preferably in the upper center part of the cap. In one form, these venting means suitably comprise a one-way valve of the nap or diaphragm type. The valve shown includes an aperture il through the cap laminate. An apertured rubber or other iiexible disk il is applied around the outer face of this aperture and united to the outer side of the cap. Its central aperture 42 is of about the same diameter as the aperture @is and the edges of this aperture lie inwardly adjacent the edges of the aperture ed. A rubber or similar disk lis is applied over the disk di and is thereto united inward of its periphery.

Several apertures M are provided radially outwardly oi the aperture d. In normal condition, disk i3 lies nat on disk l with the apertures out of register, sealing the container against any ingress oi' warm air. Upon the building up of a slight internal pressure the disk #33 rises in the center, opening a path for the egress of air from the container through apertures '32 and 44.

In order to securely anchor the container to its supporting floor during transit in a manner enabling ready removal thereof at its destination, apertures 555, forming one component of a holddown arrangement, are provided at a plurality of suitable locations around the peripheral edges of the load base. Through these apertures, bolts lili, or other suitable elongate fasteners such as one ci the cam locking types, are passed into engagement with a suitable complemental means in the tief-down recesses i8 usually found in the cargo deck oi' transport vehicles. In the present embodiment the complemental means consist of bossed apertures i? into which the bolts may be threadedly engaged. The apertures are spaced apart distances correlated laterally and longitudinally with the spacing of the recesses 4S in he compartment iioor so thatif desired. conn tainers of varying horizontal dimensions may be suitably fitted together in a pattern made up of a plurality of units laterally and a certain other number or units longitudinally on the deck, these numbers being varied to suit the floor area of vari-ous of cargo aircraft, motor trucks or By the construction aforen described, or its equivalent, the ibrations and ations of the transporting vehicle are rendered ineffective and are unable to displace the container, the construction of the latter prevents internal displacement oi its: contents.

I+ is elieved that the steps of loading and handling con er, the functioning of the container drring transit, and the steps of unloading the container' at destination will be self-evident from the for oing description.

'l'o meet contingency that no return cargo of a rrisliable nature, or ci any other nature making use ci these containers worthwhile, is available, it is contemplated that the container can beA disassembled, part by part, and stored nu of the aircraft, or in its over- Foor space is thus cleared for able available cargo so that the Vehicle may return full. To this end, it is only necessary to unfasten the lower slide fastened edges of the cap member from the base plate Il, whereupon the cap may be bodily removed and configured substantially into the illustrated form shown in Figure 8 as a compacted S laterally indented by a reverse accordion pleat. Thereafter the fastening pins 30 on the corner posts are removed, allowing the corner posts to telescope downwardly, whereupon they can be removed from the sockets 25 andstored between the upper and lower members of the pallet. The reticulate lining or retainer l2, not shown in Figure 8, occupies` a folded position inside the folded cap. The so-stacked elements may be lashed. together to constitute a unit after being placed in the condition shown in Figure 8, whereupon the unit may be stowed as aforementioned in some space not being used on the return trip.

I claim:

l. A container comprising: a double-deck pallet having an open-framework lower deck and a continuous thermally insulated upper deck perpendicularly spaced therefrom to inhibit heat transfer therebetween and to provide a receiver for lift truck prongs; a thermally insulated, flexible cover in the form of an inverted bag detachably attached at its lower peripheral edges to the subadjacent edges or said upper deck; means carried by said pallet for precooling said container; and means carried by said pallet and surrounded by said cover for enabling various conditions of vertical extension of said cover to be attained and maintained, thereby to vary the volumetric capacity of said container.

2. A container, comprising: a double deck pallet having an open-framework lower deck and a substantially continuous thermally insulated upper deck perpendicularly spaced therefrom to inhibit heat transfer therebetween and to provide a reoeiver under the container for lift truck prongs; a thermally insulated, flexible cover in the form of an inverted bag detachably attached at its lower peripheral edges to the subadjacent edges of said upper deck; a lateral-thrust taking liner framework detachably mounted on said upper deck within said cover; means carried by said pallet for precooling said container; and means for electing variations of the vertical dimension of said framework, thereby to vary the volumetric capacity of said container.

3. A container, comprising: a hollow, substan` tially airtight enclosure including means in all the walls thereof for substantially precluding heat transfer from the outside to the inside of the enclosure and thermally isolating said hollow from the ambient air and surrounding objects; means for entraining a frigid gas into said container and for enabling controlled venting therefrom of excess gases; and means forming a part of said enclosure for providing' access to the bottom of said container to enable loading the latter with transportable items; whereby to enable perishable goods to be transported, without detrimental eiTect-s, in the same uninsulated, unrefrigerated and unhumidiiied transport compartment as those susceptibie to cold and moisture.

fi. A contain-er of the construction set forth in claim 3; said means for entraining said frigid gas into said centaine1 comprising a dual-function post-and-conduit defining and supporting at least one of the corners of said enclosure and including a heat insulating lining in its lower end and terminating at its upper end in a gas outlet and 9 having a gas inlet connection on the one`side of its lower end.

5. A container of the construction described in claim 3; said means for venting" said container comprising a portion of thev upper surface of said enclosure having an aperture therein; an apertured, flexible, thermally nonconductive plate mounted air-tightly thereon around said aperture and a flexible, thermally non-conductive plate having a perforatecentral region mounted on the outer side of the rst said plate with the perforations thereof lying radially beyond the first said aperture; whereby the gaseous contents of said container may pass outwardly through said aperture and perforations, whereas ambient air seeking entrance merely presses said outer plate air-tightly against said inner plate and is thus prevented from entering said container. f

6. A container substantially as described in claim 3; in which said access means include a flap formed in two opposite ends and the included face of said enclosure, the adjacent edges of the flap and the enclosure being disengageably engaged by ap slide fasteners.

'7. A package comprising: perishable goods inundated by a frigid gas; a flexible but resistant member lining the package and binding the perishables together into a compact bundle; and a substantially gas-tight thermally insulated enclosure having a part removably encompassing said lining and another part removably attached to the rst said part and taking the vertical loads originating with said perishables; whereby to enable storage and transport of said perishables for a relatively prolonged time without substantial deterioration thereof or substantial damage thereto.

8. A container according to claim '7, in which the flexible resistant lining member comprises an inverted cap-like member open at the one end and made up of a plurality of rectangularly crossing strips of iiexible, tough material mutually united at their crossing points to denne a reticulate web; snap catches mounted at each of the lower few courses of strips at the intersections thereof and disposed to engage downwardly; and

a plurality of complementary catches disposed on said base to register with and be engaged by said snap catches when said lining is collapsed thereby to maintain the lateral integrity and resistance of said lining in all vertical conditions of said container.

9. A transit container for perishable contents, comprising: a hollow, iiexible substantially air- `tight thermally insulated enclosure including means for entraining a frigid gas thereinto and for containing same therein; said enclosure including a telescopable corners-dening framework supporting the insulated, relatively flexible walls collapsible therewith on retractive telescoping of said framework and extensible on protractive teleseoping thereof; and a pallet detachably attached substantially gastight to said enclosure at said open end and dually constituting a rigid bottom for the container and means for engagement by a lift truck in handling the container; said means for telescopably supporting said enclosure enabling alteration of the interior volume of said container to enable variation of the ratio of outhaul contents to backhaul contents, thereby to enable one and the same container to function efliciently with Variable quantities of contained goods.

10. A container, comprising: a flexible, heat insulated, airtight cap, having the one end open;

/ a rigid member having its peripheral edges disengageably engaged air-tightly with said cap; a vertically telescopable post removably mounted at each of the corners of said rigid member; and a flexible lining carried by said posts within said cap; whereby said posts and lining may be telescoped, removed from said base and stacked thereon in parallelism therewith, and the cap may be removed from said base and folded down on it in compact form, thereby to reduce said Vcontainer substantially to the minimum compass for stowage off the cargo oor.

l1. A collapsible shipping container for carrying perishables inundated by a volume of frigid gas, comprising: an open-ended, flexible bag organized and constructed for taking the lateral ioads of the container contents; a rigid thermally insulated base adjacent the lower end of said bag; a plurality of vertically telescopable postsframi-ng and defining the vertical extent and thevolune of the container and removably carried by said base and collapsibly carrying said flexible bagj and an inverted open-ended flexible and collapsible, thermally insulated cap surrounding the aforesaid parts and detachably attached at its lower peripheral edges to the subadjacent periphery of said base.

12. The method of preserving a perishable during transit in an uninsulated, unrefrigerated and unhumidified transport compartment without substantial deterioration thereof or damage thereto, comprising: segregating the perishable air tightly from the circumambient air while thermally isolating same from said'air and surrounding objects, thereby to prevent heat transfer thereto; precooling the segregated perishable before transit thereof; and maintaining the aforesaid segregative and thermal conditions during transit independently of further refrigeration and regardless of the changes in temperature and humidity of the transporting compartment.

13. The method of preserving a perishable during transit in a non-humid, unrefrigerated, thermally uninsulated transport compartment, without substantial deterioration thereof or damage thereto, comprising: conning the perishable in a substantially hermetically sealed, heat isolated space; entraining a frigid gas into said space before transit in an amount sufficient to precool and humidify the contents of said space; and maintaining the low heat level and high humidity of said space during transit independently of further refrigeration and regardless of circumambient thermal and humidity conditions and at values sufficient to prevent deterioration of or damage to said perishable. i

14. A continuous-refrigeration eliminating perishable cargo transporter, comprising: a substantially air-tight container adapted to physically and thermally segregate the Y perishable from the circumambient air and surrounding objects; means for inserting thereinto an amount of a frigid gas suicient to maintain the perishable at a non-deteriorative heat level for a predetermined time and means in the container walls for thermally isolating the contents of the container and preventing transfer of heat from the circumambient atmosphere and contacting objects to the precooled contents of said container.

15. A container, comprising: a thermally insulated bottom; a thermally insulated flexible and collapsible cover forming the container top and sides and attached at its lower edges to the subadjacent edges of said bottom; vertically telescopable means xed in upright attitude to said bottom and supporting said cover in various vertical positions of the latter to vary the volume of the container; and means for enabling precooling of said container disposed entirely within the outlines of the container and leaving the eX- terior of the container free of protuberances, thereby to enable stowage of a plurality of the containers in close juxtaposition to each other.

16. A container, comprising: a double-deck bottom, the upper deck of which is thermally insulate-d and the lower deck of which is vertically spaced from the upper deck to provide a receiver space for lift-truck, and other prongs; a thermally insulated flexible cover forming the top and sides of the container and attached at its lower edges to the subadjacent edges of said bottom; vertically telescopable means xed in upright attitude to said bottom and supporting said 12 exible cover in various -Vertical positions of the latter to vary the volume of the container; and means for enabling pre-coolingr of said container disposed entirely Within the outlines of the container and leaving the exterior of the container free of protuberances thereby to enable stowage of a plurality of the containers in close juxtaposition to each other.

BRUCE E. DEL MAR.

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

UNITED STATES PATENTS Number Name Date 647,113 Burmingham May 14, 1901 1,470,653 Sullivan Oct. 16, 1923

Images