US 2738654 A
Description (OCR text may contain errors)
March 20, 1956 2,738,654
R. R. ELSTON ET AL CARGO COOLERS Filed Sept. 2, 1953 United States Patent@ 2,138,654 y CARGO cooLERs Application September 2, 1953, Serial N o. 377,994 5 Claims. (ci. 6z91.s)
This invention relates to improvements in coolers which are adapted for use in trucks and trailers to guard against the spoilage of freight or cargo of a perishable nature while in transit in warm weather, and particularly to coolers of the class adapted to contain solid carbon dioxide or Dry Ice asa refrigerant.
It is an object of our invention to provide in a cooler of this class a novel and eicient arrangement of refrigerant compartments having heat conducting walls of relatively large area, the outer surfaces of which are disposed to absorb heat rapidly from an air stream which is conducted in a sinuous path over these surfaces.
A further object is to provide in a cooler of the class described a plurality of compartments arranged to be filled with blocks of Dry Ice and of such elongated form as to contain a maximum number of refrigerant blocks of standard size and shape. A j
A particular object is to increase the area of the chilled surfacesY exposed to an air stream in the cooler by providing a vertical series of elongated compartments having bottom walls directly supporting the refrigerant,` constructh 2,138,654 l Patented `Mar.; 2,0, 19,5 6
ners 15 and are supported in sealed relation to the end wall 5 and to the end wall 6 at each side of the openings.
Spaced outward from and in parallel relation to the wall members 13 and 14 are conduit members 16 and 17 forming with these compartment walls air passages 18 of sinuous shape at opposite sides of the several refrigerant compartments. Warm air is admitted to the passages 18 through an elongated intake opening 19 formed in the bottom wall 7 of the casing and air is drawn upward through these passages by a motor driven blower 20 mounted in a circular discharge opening 21 formed in the top wall 8 of the casing. From the blower 20 the cool air current passes through a discharge conduit 22 having a side opening 23 and a series of adjustable control members 24. These members 24 are pivotally mounted within the conduit 22 to direct and control the volume of refrigerated air which is discharged into the cargo space through the opening 23.
The discharge conduit 22 is formed at its base with a circular flange 25 which tits a similar flange 8a formed on the top wall 8 so that this conduit may be rotated about the axis of the blower 20 to direct the cool air to any part of the cargo space. This adjustment makes it feasible to place the cooler in a convenient place in the cargo space and deliver the cool air to any selected part of the space to be cooled.
Each of the chambers 10 has an outlet port 26 for the gas given off by the refrigerant and the several ports 26 communicate with a vertically extending header tube 27 carried by the end wa1l 5 of the casing. From the lower end of the tube 27, a pipe 28 extends downward through ed from material having good heat conducting characterl I istics and having substantially their entire outer surfaces exposed to the air stream to be cooled.
Our invention also includes certain other novel features of construction which will be more fully pointed out in the following specification and claims.
In the accompanying drawing a preferred embodiment of our invention is illustrated by way of example and not for the purpose of limitation.
Referring to the drawing:
Figure l is a perspective view of the cooler with the door open and portions of two of the outer casing walls broken away to show the interior construction;
Fig. 2 is a vertical sectional view through the cooler and a portion of the supporting vehicle floor, and
Fig. 3 is a fragmentary perspective view showing the end of the cooler remote from the door.
Our improved'cooler has a substantially rectangular outer casing comprising side walls 4, end walls 5 and 6, a bottom wall 7 and a top wall 8. Hingedly connected to the outer casing along one vertical corner is a door 9 affording access to a plurality of compartments 10, each adapted to contain a plurality of blocks of a refrigerant such as Dry Ice. These compartments are horizontally elongated, closed at one end and have openings in the end wall 6 which are accessible when the door 9 is open for filling the compartments with the refrigerant. As shown in Fig. 1, suitable latch members on the door are engageable with keepers 11 projecting from the casing. A compressible gasket 12 is attached to the door 9 and adapted to seal the closure against the escape of gas from the compartments 10 when the door is closed. Each refrigerant compartment comprises side walls composed of downwardly converging members 13 and upwardly converging members 14 and is approximately square in vertical cross section. The several compartments are suitably connected together along their horizontally extending coran opening in the floor of the vehicle indicated at 29 so that exhaust gas may be discharged exteriorly of the cargo space when thisis desirable. The tube 27 is also provided with a side discharge port 30 through which the gas may be discharged into the cargo space when this is desirable. The port 30 is normally closed by-a valve member 31 tixed on a horizontally extending rod 32 having a handle 33 located below the door 9. A spring 34 is provided to bias the valve member 31 to close the port 30 and a keeper 35 is mounted adjacent to the handle 33 for engagement with the handle when it is desired to retain the valve member 31 open relative to the port 30.
Some types of perishable cargo are damaged by the presence of abnormal concentrations of carbon dioxide in the cargo space. In a vehicle carrying such cargo the valve member 31 is retained in closed relation to the port 30 and the carbon dioxide gas, as it is formed in the cornpartments 10, is discharged through the ports 26 and downward through the header tube 27 and pipe 28 to the exterior of the cargo space. When carrying other types of cargo, it is desirable to utilize the cooling effect of the carbon dioxide gas and the handle 32 may be engaged with the keeper 35 to hold the valve member 31 open relative to the port 30 so that the gas is discharged into the cargo space.
Frame members 35 connected by cross members 37 project below the bottom wall 7 of the casing to support the cooler n spaced relation to the door 29 of the vehicle.
The wall members 13 and 14 of the compartments 10 are constructed from a material or materials having good heat conducting properties, e. g., a suitable aluminum alloy, so that there is a rapid conduction of heat through these wall members to the refrigerant.
Our improved cooler may be placed in any convenient location within the cargo space and power for operating the blower motor may be supplied from the vehicle battery. When cooling is required the compartments 10 are filled with blocks of Dry Ice or other suitable refrigerant, the door 9 is closed and fastened in sealing relation to the end wall 6, the blower 20 is operated to draw air up through the intake opening 19, sinuous conduits 18 where the heat transfer takes place. The cool air is discharged through the opening 21 into the conduit 22 from which it is blown out through the openings 23 under control of the adjustable members 24.
Simplicity combined with high efficiency -are obtained by reason of the fact that the entire, unusually large outer surfaces of the wall members 13 and 14 are exposed in heat transfer relation to the .current of air in the conduits 18. This makes it unnecessary to provide ns and other projecting members such as are usually employed to increase the refrigeration area. The rate of absorption of heat and output of cool air may be regulated according to requirements, by adjusting the positions of the control members 24. As long as there is a supply of refrigerant in the compartments the Wall members 13 supporting the refrigerant and wall members 14 remain at substantially the same low temperature so that a continuing substantially uniform and high rate of absorption of heat is obtainable when required.
Having described our invention, what we claim as new and desire to protect by Letters Patent is:
1. In a cooler for the cargo space of a vehicle, a plurality of compartments of substantially rectangular shape disposed one above another, corner to corner, each having side walls including downwardly converging side Wall members adapted to support a refrigerant body within the compartment and end walls for confining said body, said side walls having good heat conducting properties and a conduit formed to conduct a stream of air in a sinuous path upward at opposite sides and in contact with substantially the entire exterior surfaces of said side walls.
2. A cooler in accordance with claim 1 wherein the upper portion of each of said compartments comprises upwardly converging wall members.
3. In a cooler for the cargo space of a vehicle, a plurality of compartments of substantially rectangular shape disposed one above another, corner to corner, each having inclined side walls adapted to support a refrigerant body within the compartment and a top and end walls for coniining said body, a warm air conduit formed to conduct a stream of air upward and in heat transfer reiation with substantially the entire exterior surfaces of said said walls, a substantially rectangular outer casing having side walls spaced from the side walls and top wall of said compartments, said casing being formed with an air inlet opening communicating with the lower end of said warm air conduit and an air outlet opening communicating with the upper end of said conduit, a discharge conduit mounted on the top of said casing for rotary movement about a vertical axis, said discharge conduit having an outlet opening adapted to discharge air laterally into the cargo-space and a blower disposed in said casing .to force air from the upper portion thereof out through said discharge conduit.
4. In a cooler for the cargo space of a vehicle, a plurality of compartments each having end walls and inclined side walls angularly disposed one 4to another and defining centrally disposed parallel corners, said compartments be ing disposed corner to corner with the adjoining corners defined by the inclined side walls in a common centrally located plane, and a conduit formed to conduct a stream of air in a sinuous path in contact with substantially the entire exterior surfaces of said side walls.
5. A cooler in accordance with claim 4 wherein each of said compartments has inclined right angnlarly disposed side wall members defining top and bottom corners extending in a common substantially vertical plane with the corresponding corners of another compartment.
References Cited in the le of this patent UNITED STATES PATENTS Re. 19,950 Rice Apr. 2,8, 1936 2,027,336 Hanson Jan. 7, 1936 2,055,158 Rice Sept. 22, l192136 2,065,985 Rice Dec. 29, 1936 2,073,700 Keilholtz Mar. 1,6, 1937 2,070,044 Gilpin Feb. 9, 1937