US3498237A

US3498237A - Insulated wall structure for containers and method of forming

Info

Publication number: US3498237A
Application number: US558650A
Authority: US
Inventors: Arthur F Loveland; Glenn W Sitler
Original assignee: ACF Industries Inc
Current assignee: ACF Industries Inc
Priority date: 1966-06-20
Filing date: 1966-06-20
Publication date: 1970-03-03
Anticipated expiration: 1987-03-03

Description

March 3, 1970 A. F. LOVELAND ETAL INSULATED WALL STRUCTURE FOR CONTAINERS AND METHOD OF FORMING 4 sheets-sheet 1 Filed June 20, 1966 FIG. 2.

INVENTORS.

ARTHUR F. LOVEL'AND GLENN W. SITLER BY ZJ M ATTORNEY March-3, 1970 A. F. LOVELAND ETAL 3,493,237v

INSULATED WALL STRUCTURE FOR CONTAINERS AND METHOD OF" FORMING Filed June 20, 1966 I 4 Sheets-Sheet 2 FIG. 3.

'' March 3, 1970 A. F. LCVELAND ETAL 3, 35 73 INSULATED WALL STRUCTURE FOR CONTAINERS AND METHOD OF FORMING Filed June 20, 1966 4 Sheets-Sheet 5 I March 1970 A. F. LOVELAND ETAL 3,493,237

INSULATED WALL STRUCTURE FOR CONTAINERS AND METHOD OF FORMING Filed June 20, 1966 4 Sheets-Sheet 4 FIG. 5.

Ill 0 9:4

United States Patent 3,498,237 INSULATED WALL STRUCTURE FOR CONTAIN- ERS AND METHOD OF FORMING Arthur F. Loveland, St. Charles, and Glenn W. Sitler, St. Louis, Mo., assignors to ACE Industries, Incorporated, New York, N.Y., a corporation of New Jersey Filed June 20, 1966, Ser. No. 558,650 Int. Cl. 361d 17/18, 17/08, 17/12 US. Cl. 105-355 8 Claims ABSTRACT OF THE DISCLOSURE An in-place foam insulated wall for a container structure, such as a railway car, in which a pair of spaced, generally parallel sheets are secured adjacent the outer wall of a container and form an enclosure in which the expanding foam material is poured. A slightly flexible outer sheet is spaced from the outer wall and is lightly fastened to have a lesser resistance to flexure and bulging from the internal pressure of the foam material. The outer sheet tends to bulge or bow outwardly into the space adjacent the outer wall upon expansion .of the foam material.

Heretofore, in containers such as railway box cars, insulated wall structures have been formed in-place within the box car employing a suitable rigid plastic foam of a cellular structure, such as a polyurethane, polystyrene, epoxy, silicone, phenolic, or syntactic foam material. For example, a polyurethane foam system employs several ingredients which are mixed together and then applied to an enclosure with a subsequent expansion to fill the enclosure. The following ingredients are normally mixed: (1) a polyether or polyester base, (2) an isocyanate base employed as an activator, (3) a fluorocarbon blowing agent, and (4) a catalyst. As the foam material expands into the enclosure to form a rigid cellular structure, the expanding material exerts a pressure against the framework forming the enclosure and in many instances, particularly if the adjacent sides or sheets forming the enclosure are not of a substantial rigidity, will tend to bulge or wrinkle the adjacent sheets. Such sheets or sides which buckle or wrinkle present an irregular surface and displeasing appearance when exposed to view and are undesirable. One method heretofore employed with inner sheets forming the interior exposed wall surface of a railway box car has been to provide bracing to reinforce the walls against buckling with the bracing being removed after the insulating material is poured and becomes a rigid cellular structure. The installation and subsequent removal or bracing is costly as well as time consuming.

This invention comprises the use of a pair of spaced, I

generally parallel sheets secured adjacent the outer wall of a container and forming an enclosure into which an expanding foam material may be poured, the outer sheet being spaced from the outer wall and having a less r resistance to flexure and bulging from the internal pressure of the expanding foam material than the inner sheet.

The outer sheet is at least slightly flexible and will tend to bow or bulge outwardly into the space formed between the outer sheet and the outer wall upon the expansion of any foam insulation material thereby to maintain the exposed inner sheet and the exposed outer wall with a minimum of surface irregularities. As the space between the outer wall and the outer sheet remains a void, only a minimum of foam material is employed.

It is an object of this invention to provide an insulated wall structure with an expanding foam material which is formed in-place within a container, such as a railway box car, highway trailer, or detachable portable container.

Another object of this invention is the provision of such an insulated wall structure in which a minimum of bracing or shoring is required in order to form the wall structure and a minimum of foam material is employed.

A further object of this invention is the provision of such an insulated wall structure in which the exposed surfaces of the wall structure have a minimum of surface irregularities and present a pleasing appearance.

An additional object of this invention is the provision of a method to form such an insulated wall structure from an expanding foam material in which a minimum of shoring or bracing is required.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated,

FIGURE 1 is a side elevation of a railway box car with which the present invention is commonly employed;

FIGURE 2 is a transverse section of the railway box car shown in FIGURE 1 and illustrating the railway car before the expanding foam material is applied;

FIGURE 3 is a partial side elevation with certain parts broken away and illustrating the foam material for the roof structure;

FIGURE 4 is a transverse section of the upper wall structure or roof structure employing the present invention with an insulating material of an expanding foam material between a pair of sheets;

FIGURE 5 is an enlarged fragment of FIGURE 4 illustrating the bulging or bowing of the outer sheet and the means permitting such bulging;

FIGURE 6 is a schematic view in plan illustrating the general method employed in applying the foam material to the roof structure;

FIGURE 7 is a transverse section of the side wall structure employing the present invention with an insulating material of an expanding foam material in the cavity or space provided between a pair of sheets; and

FIGURE 8 is a longitudinal sectional view of the side wall structure illustrating the space between the pair of sheets to receive the expanding foam material and the means to permit a bulging of the outer sheet.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawmgs.

Referring to the drawings, a railway box car is indicated generally at 10 in FIGURES 1 and 2 and includes side wall structures 12, end wall structures 14, an upper wall or roof structure 16, and a lower or bottom wall structure 18. The present invention may be employed with any wall structure although only the side 'wall structure and the upper wall structure have been illustrated in the drawings as employing the present invention. While a railway box car 10 is illustrated in the drawings, it is to be understood that the present invention is applicable to other structures, such as highway trailers or detachable containers.

It is desirable in many instances to provide an insulated container to maintain a generally constant temperature within the container and to minimize heat transfer between opposite sides of the wall structures forming the container. Expandable foam materials, such as polyurethanes, polystyrenes, epoxies, silicones, phenolics, and synthetics, have been found to be satisfactory for the insulating material. Upon expansion of the foam material, pressure is generated and acts against the confining surfaces tending to press the surfaces outwardly. Especially when a relatively thin sheet is exposed interiorly of the container, wrinkles or bulges may develop which present a displeasing appearance. While such Wrinkles or bulges can be controlled when a prefabricated or preformed insulated panel is made, it is very diflicult to control'when the insulated wall structure is formed in place with sheets of a small thickness.

Referring particularly to FIGURES 3-5, the upper wall structure or roof structure 16 is illustrated. Roof structure 16 comprises a side plate 20 of a W configuration in cross section, and a roof 22 extending over side plate 20 and secured thereto, such as by welding or riveting. Extending between side plates 20 is a ceiling panel or sheet 24 exposed to the interior of box car and formed of plywood around one-half /2) inch in thickness. A side panel or sheet 26 of one-half /2) inch plywood forms an interior side lining of box car 10 and is spaced from an outer lining or wall 28 formed of sheet metal around one tenth (.10) inch in thickness. A longitudinally extending wooden strip 30 is secured to an interior side sheet or lining 26 and sheet 24 is nailed between opposite strips 30. An intermediate wooden filler strip or spacer 34 is secured to sheet 24 and extends longitudinally of railway car 10. Transversely extending wooden carlines 34 are spaced along the length of car 10 and are secured to spacer 34. An outer sheet generally indicated 37 is formed of a pair of sheet portions or sections 36 being of a thickness of around one fourth A) inch and slightly flexible are secured over spacer 34 and carlines 35. To secure sheet sections 36 to spacer 34, nails 38 are positioned along the marginal edge portions of sections 36 but are not nailed tightly against sections 36. Thus, the heads of nails 38 are slightly spaced from the adjacent surfaces of sections 36 when the sections 36 are initially positioned. Sheet sections 36 are also lightly fastened to carlines 35 with suitable fasteners such as nails. The fasteners of sections 36 to carlines 35 are easily pulled loose when pressure is formed by the foam material to permit bowing of sheet 37. Nails 38 securing sections 36 to spacer 34 do not pull loose, however, as sections 36 tend to tear around nails 38 when pressure is exerted against the inner surface of sections 36.

Referring particularly to FIGURE 6, apparatus is indicated at 40 adjacent each end of car 10 to mix the ingredients of the foam material. Dispensing tubes 42 lead from each apparatus '40 within the space formed between

sheets

24 and 37 and through suitable openings 46 in carlines 35. As the foam material is dispensed from the ends of tube 42, the tubes are withdrawn slowly through the openings in carlines 35. The foam material after being dispensed from the ends 44 of tubes 42 expands to fill the cavity or space between outer sheet sections 36 and lower sheet 24. Outer sheet 37 may be formed of plywood, masonite, or other slightly flexible material which has a lesser resistance to flexing or bulging than sheet 24 since sheet 37 is of a lesser thickness. As nails 38 are in the marginal edge portions of sections 36 closely adjacent the edges thereof, the bulging of sheet 37 tends to tear or rip the sections immediately adjacent nails 38 thereby permitting sheet 37 to bulge or how to the shape shown in FIGURES 4 and 5. Sheet 24 has only a minimum of bulging and thereby generally maintains its initial shape. While sections 36 how, nails 38 retain sections 36 in position as the sections do not completely tear away from nails 38. However, sections 36 do bow or pop away from carlines 35 under pressure of the expanding foam material as sections 36 are only lightly nailed or fastened to carlines 35. Thus, sheet sections 36 act as a pressure relief to prevent excessive pressures being exerted against sheet 24. Sheet 37 minimizes the amount of insulating material employed in roof structure 16 as sections 36 are spaced from roof 22 and foam material is not used in the space formed between sheet 37 and roof 22.

Referring to FIGURES 7 and 8, an insulated side wall structure 12 is illustrated. Side posts 48 of a generally channel shape are spaced along the length of outer lining or outer Wall 28 to reinforce the side sheet. Outer wall 28 is formed in a plurality of portions each welded to adjacent side posts 48 as shown in FIGURE 8. As lining 28 is normally of sheet metal having a thickness of around one-eighth 4;) inch, the expanding foam material if poured in contact with wall 28 will tend to wrinkle or bow wall 28 thereby presenting an unpleasing appearance. Mounted between outer wall 28 and interior sheet 26 is an outer sheet generally indicated 49 formed of a pair of sheet sections 50 adapted to bow or bulge when the expanding foam material is positioned between

sheets

26 and 49 thereby preventing or minimizing any bowing of wall 28.

To secure inner sheet 26 and outer sheet 50, a plurality of studs 52 are welded to the inner face of each channelshaped post 48 and extend through suitable openings in wooden posts 54 and wooden spacers 56. Posts 54 are first positioned on studs 52 and the marginal edge portions of sections 50 are nailed to posts 54, spacer 58 being previously secured to a pair of sections 50 by nails 60. Nails 60 are positioned along the marginal edge portions of sections 50 to permit a slight tearing out with the heads of nails 60 being slightly spaced from the adjacent surface of sections 50. Next, spacers 56 are mounted'on studs 52 and nuts 62 are drawn tight to hold posts 54 and spacers 56 in secured position. Inner sheet 26 is then nailed to spacers 56. The expanding foam material is applied within the void formed between sheet 26 and sections 50 in a manner similar to that illustrated in FIGURE 6 for roof structure 16. Suitable openings 64 are provided in spacers 56 and 58 to receive a foam dispensing tube and the tube is withdrawn slowly as the space is filled between

sheet

26 and 49. In most instances side wall structures 12 are insulated first and then roof structure 16 is insulated. It is noted that a passage is provided between the void space in roof structure 16 and thevoid space in side wall structures 12. Thus, an overflow of foam material from side wall structures 12 into roof structure 16 may occure when side wall structures 12 are first poured. This permits a type of pressure relief for side wall structures 12.

Referring to FIGURE 2, the bottom wall or floor structure 18 may be insulated by the dispensing of foam material in the void space beneath the floor panel 65. Cross members 66 have openings to receive a dispensing tube. Stringers 68 extend longitudinally and a lower sheet 70 is secured beneath stringers 68. Sheet 70 is not shown as being flexible and bowing or bulging when the foam material is applied. However, if desired, a floor structure similar to roof structure 16 could be provided having a flexible outer sheet to bow thereby to prevent bowing of floor panel 65.

From the foregoing, it is to be understood that the present invention provides an in-place insulation for a wall structure in a container, such as a railway box car in which a flexible sheet is arranged to act as a pressure relief for expanding foam materal thereby to prevent excessive pressure being applied against an adjacent spaced sheet or wall.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results obtained.

What is claimed is:

1. A method of forming an in-place insulating wall structure for a railway box car comprising the steps of initially securing a pair of generally parallel spaced sheets in place within the box car for forming the wall structure with the sheets forming an enclosure therebetween, and placing an expanding foam material within the enclosure formed between said sheets with said foam material expanding to fill the enclosure and forming a rigid cellular foam insulation between the sheets, one of said sheets being more flexible and less resistant than the other sheet to the pressure generated by the expanding foam material as it fills the space between the sheets with said one sheet tending to bulge and flex outwardly thereby to minimize any pressure generated by the foam material against the other sheet to maintain the other sheet with a minimum of surface irregularities.

2. The method as set forth in claim 1 and further comprising the steps of forming said one sheet of two adjacent sections arranged in edge-to-edge relation, positioning a spacer between the tWo sheets at the juncture of said adjacent sections, and lightly fastening the marginal edge portions of the two sections to said spacer whereby the expanding foam material urges the sections away from said spacer to permit bulging of the sections.

3. A method of forming an in-place insulating panel adjacent an outer wall of a container body, comprising the steps of positioning a pair of generally parallel spaced sheets adjacent said outer wall with the outer of said sheets being spaced from the outer wall to form an open space between the outer wall and outer sheet and placing an expanding foam material within the open space formed between said sheets with said foam material expanding to fill the space between the sheets and forming a rigid cellular foam insulation, the outer of said sheets being more flexible and less resistant than the outer sheet to the pressure generated by the expanding foam material as it fills the space between the sheets with said outer sheet tending to bulge and flex into the space between said outer wall and said outer sheet to relieve any pressure generated by the foam material against said inner sheet thereby to maintain the inner sheet and the outer wall with a minimum of surface irregularities.

4. The method as set forth in claim 3 further comprising the steps of forming said outer sheet of two adjacent sections arranged in edge-to-edge relation, positioning a spacer between the two sheets at the juncture of said adjacent sections, and lightly fastening the marginal edge portions of the two sections to said spacer whereby the expanding foam material urges the sections away from said spacer to permit bulging of the sections.

5. A framing structure secured within a container body adjacent an outer wall thereof and forming a permanent portion of said container body, said framing structure adapted to receive an expanding foam insulation material therein for forming an in-place insulating panel adjacent said outer wall, said framing structure comprising an inner sheet forming an exposed interior surface for the container body, an unexposed outer sheet spaced outwardly from the inner sheet in generally parallel relation thereto, means to hold the sheets in generally parallel spaced relation to form an open space therebetween, said outer sheet being spaced from the adjacent outer wall of the container body to form a space therebetween and comprising two adjacent sections arranged in edge-to-edge relation, an intermediate spacer between the two sheets at the juncture of the adjacent sections, and means lightly fastening the marginal edge portions of the two sections to said intermediate spacer whereby said sections are adapted to be urged away from said intermediate spacer when expanding foam material is positioned in the space between the two sheets, said outer sheet being less resistant to internal pressure from an expanding foam material than said inner sheet and adapted to bulge outwardly into the space formed between the outer sheet and the outer wall upon the expansion of any foam insulation material positioned between the sheets to minimize any excessive pressure applied against the inner sheet from the expanding foam material thereby to maintain the exposed inner sheet and the outer wall with a minimum of surface irregularities.

6. A wall structure for a railway box car comprising an outer wall forming a permanent portion of said container body, a pair of generally parallel spaced sheets positioned inwardly of said outer wall, means to hold the sheets in generally parallel relation with said outer sheet being spaced from the adjacent outer Wall of the container body to form a space therebetween, said outer sheet being less resistant to internal pressure from an expanding foam material than said inner sheet and adapted to bulge outwardly into the space formed between the outer sheet and the outer wall upon the expansion of any foam insulation material positioned between the sheets to minimize any excessive pressure applied against the inner sheet from the expanding foam material thereby to maintain the exposed inner sheet and the outer wall With a minimum of surface irregularities, said outer sheet comprising two adjacent sections arranged in edge-to-edge relation, and means adjacent the juncture of the adjacent sections lightly fastening the marginal edge portions of the two sections whereby said marginal portions are adapted to be unfastened and urged outwardly to permit a bulging of the outer sheet when expanding foam material is positioned in the space between the two sheets.

7. A wall structure for a railway box car as set forth in claim 6 wherein said wall structure is an upper wall structure and said outer wall is a roof, said inner sheet forming a ceiling for the box car and exposed to the interior of the box car, said outer sheet comprising at least two adjacent sections arranged in edge-to-edge relation, and means adjacent the juncture of the adjacent sections lightly fastening the marginal edge portions of the two sections whereby said sections are adapted to be unfastened and urged outwardly to permit a bulging of the outer sheet when expanding foam material is positioned in the space between the two sheets.

8. A wall structure for a railway box car as set forth in claim 6 wherein said wall structure is a side wall structure and said outer wall is a side lining formed of a sheet metal material having a relatively small thickness, said inner sheet forming the inner lining exposed to the interior of the box car, said outer sheet comprising at least two adjacent sections arranged in edge-to-edge relation, and means adjacent the juncture of the adjacent sections lightly fastening the marginal edge portions of the two sections whereby said sections are adapted to be unfastened and urged outwardly to permit a bulging of the outer sheet when expanding foam material is positioned in the space between the two sheets.

References Cited UNITED STATES PATENTS 4/1961 Kloote et a1. 360 4/ 1967 Kravskopf 105--360