US3598463A

US3598463A - Shelf with integral front

Info

Publication number: US3598463A
Application number: US813155A
Authority: US
Inventors: Keith K Kesling
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1969-04-03
Filing date: 1969-04-03
Publication date: 1971-08-10
Anticipated expiration: 1988-08-10

Abstract

In the preferred form, the inner sheet plastic door panel has formed in it an integral shelf and an integral shelf front in which the plastic sheet envelops a reinforcing bar above and parallel to the shelf.

Description

O United States atent Inventor Keith K. Kesling Dayton, Ohio Appl. No. 813,155

Filed Apr. 3, 1969 Div'sion of Ser. No. 684.049. Nov. 17, 1967, Pat. No. 3.467 .741

Patented Aug. 10, 1971 Assignee General Motors Corporation Detroit, Mich.

SHELF WITH INTEGRAL FRONT lClaim,5Drawing Figs.

U.S.Cl 312/214, l8/35,2l1/l35,21l/153,312/l38 lnt.Cl A47f3/04,

[50] FieldofSeareh 211/153, 135; 312/138 A, 214; 264/92, 90; 18/35. 42, 45

[56] References Cited UNITED STATES PATENTS 2,903,315 9/1959 Schory etal. 312/214 3,401,996 9/1968 Rembold et al 312/214 FOREIGN PATENTS 840,855 7/1960 Great Britain 312/214 Primary Examiner- Ramon S. Britts Attorneys-William S. Pettigrew, Frederick M. Ritchie and Edward P. Barthel ABSTRACT: In the preferred form, the inner sheet plastic door panel has formed in it an integral shelf and an integral shelf front in which the plastic sheet envelops a reinforcing bar above and parallel to the shelf.

PATENTEU AUG 1 019m K/ /)/V/ W f ilmlmlmlml w 7 m K ATTORNEY SHELF WITH INTEGRAL FRONT This application is a division of my copending application Ser. No. 684,049, filed Nov. 17, 1967 now issued US. Pat. No. 3,462,741.

This invention relates to insulated doors having plastic sheet inner walls provided with door shelves.

It is customary to make refrigerator doors with plastic inner walls. Shelves have been added in various ways such as are shown in the Saunders U.S. Pat. No. 2,837,816 issued June 10, 1958. It is not unusually difficult to provide integral shelves but the shelf fronts have been in the form of attached pieces.

It is an object of this invention to provide an integral shelf and shelf front upon the plastic inner wall of a door,

It is another object of this invention to provide an integral shelf and shelf front which contains a reinforcing bar enveloped in the plastic sheet forming the inner wall of the door. Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

IN THE DRAWINGS FIG. I is a vertical sectional view illustrating the first step in vacuum forming the inner wall of a door with integral shelves and shelf fronts embodying one form of my invention;

FIG. 2 is a vertical sectional view similar to FIG. 1 showing the completion of the vacuum forming process;

FIG. 3 is an enlarged sectional view showing the completed form ofthe shelf front;

FIG. 4 is a fragmentary perspective view showing one of the integral completed shelves with an integral shelf front; and

' FIG. 5 is a vertical sectional view taken through the completed door.

Referring now to FIG. 1, there is shown a plastic sheet which is to be formed into the inner wall of an insulated door. The sheet 20 may be of ABS copolymer or polypropylene, for example. A vacuum forming door mold 22 rests upon the support 24. This vacuum forming mold includes a relatively thick perimeter portion 26 which extends around a thin wall portion 28 provided with substantially uniform perforations 29. The upper face of the mold 22 is provided with two

shelf forming projections

30 and 32 which extend between the

wide portions

34, 36 of the side perimeter 26. The

portions

34 and 36 of the perimeter portions 26 which extend to the left of the

projections

30 and 32 are made of a width or height equal to the height or protrusion of the shelf-forming

projections

30 and 32,

According to my invention, each of these

portions

34 and 36 are provided with

notches

38 and 40 which receive and normally removably hold the rectangular

wooden sticks

42 and 44. The sheet 20 is clamped at its edges between the turned down peripheral portion 46 of the rectangular holder 48 and an open rectangular member 50 which is clamped to the upper portion of the holder 48. The sheet-holding member 48 may be provided with a plurality of infrared lamps 52 which are energized to heat the sheet 20 of plastic causing the plastic to be stretchable and formable. As the plastic 20 is heated, a valve 54 is opened to apply a vacuum to the space or chamber 56 located between the support 24 and the perforated wall 28 of the mold 22. A pipe 58 forms a connection between the valve 54 and the chamber 56. The valve 54 connects to a vacuum pipe 60.

As the vacuum is drawn, the holder 48 is gradually lowered and the sheet of plastic is drawn into the large space between the

shelves

30 and 32 by the vacuum drawing air through the perforations 30, The plastic is heated and drawn by the differential in pressure thereon until the plastic sheet 20 envelops the

shelf forming projections

30 and 32 and is also completely around the sticks comprising the reinforcing

members

42 and 44 which form separate folds in upper flange portions in the plastic sheet 20. These

sticks

42 and 44 are completely surrounded in the adjacent folds by the plastic sheet 20 and between each of the

sticks

42 and 44 and the adjacent shelf projections or

lower flange portions

30 and 32 the plastic sheet 20 comes into substantial flat contact shelf fronts or webs 66. This forms a pleasing shelf front as is shown in FIG. 4. The plastic also envelops both sides of the

shelf forming projections

30 and 32.

Before the completion of the vacuum-forming operation, the infrared lamps 52 are extinguished and the sheet plastic 20 forming the inner wall is removed from the mold 22 along with the sticks or reinforcing

members

42 and 44 which are enveloped in the folds forming the shelf fronts. The completed shelf structure is illustrated in FIG. 4. The completed door is illustrated in FIG. 5 in which the inner wall is designated by the reference character 70.

The periphery of this inner wall member is fitted within a notch extending longitudinally in the bottom 72 of the magnetic door seal 74. The outer sheet metal wall 76 has a peripheral edge 78 provided with an inturned flange 80 extending within the interior and fitting against the bottom of the magnetic door seal 74 to hold it in place. The space between the formed inner wall 70 and the outer wall 76 is preferably filled with polyurethane foam insulation 82 preferably containing an insulating gas. This foam insulation fills the hollow space formed by the

shelf projections

30 and 32 to form the reinforced

shelves

84 and 86. The foam insulation adheres to the outer metal wall 76 and the inner plastic wall 70 and is rigid enough to substantially reinforce the shelves. These shelves are further reinforced by the integral shelf fronts 66 immediately above wherein the two sheets of plastic are directly in contact. These

shelves

84 and 86 are also reinforced by the reinforcing

members

42 and 44 in the form of the sticks which are enveloped by the folds of the plastic sheet 20. By forming the shelf fronts 66 by enveloping the reinforcing

sticks

42 and 44 which are removable from the mold 22, two integral shelf fronts are provided which are formed each by a fold of the sheet of plastic 20, as an integral part thereof. By this integral arrangement, the

hollow shelf portions

84 and 86 are reinforced by the shelf fronts 66 and'the reinforcing bars or

sticks

42 and 44. The polyurethane foam 82 is relatively stiff and strong even though it is of light weight. It has sufficient adhesiveness to prevent the separation of the inner and outer walls.

While the embodiment of the invention as herein disclosed constitutes a preferred form, it is to be under stood that other forms might be adopted.

I claim:

1. In combination, an insulated refrigerator door including an outer metallic wall extending generally within a plane, an inner wall formed of plastic sheet, polyurethane foam insulation material between said inner and outer walls, said plastic sheet formed in cross section as a flanged beam by having an integral shelf portion extending substantially at right angles away from the adjacent portion of the sheet and substantially horizontally over an extensive area to a line extending in spaced relation to the adjacent portion of the sheet, wherein the improvement comprises, said plastic sheet having a substantially horizontal wooden reinforcing member of rectangular section extending above an extended portion of said shelf, said shelf portion of said sheet formed with an integral rectangularly shaped loop portion folded over and completely around said reinforcing member with opposite sides of the fold in substantially flat contact over a substantial area between said reinforcing member and said shelf to form in cross section an upper flange portion of said flanged beam, said integral loop portion extending up along said line generally perpendicular to said extensive area of said shelf portion to provide a front, said sheet extending from said loop portion beneath the shelf portion to form an integral shelf and shelf front, said shelf portion being formed by the spacing of two portions of said plastic sheet, and polyurethane foam insulation filling the space between said two portions to form in cross section a lower flange portion ofsaid flanged beam.

Claims

1. In combination, an insulated refrigerator door including an outer metallic wall extending generally within a plane, an inner wall formed of plastic sheet, polyurethane foam insulation material between said inner and outer walls, said plastic sheet formed in cross section as a flanged beam by having an integral shelf portion extending substantially at right angles away from the adjacent portion of the sheet and substantially horizontally over an extensive area to a line extending in spaced Relation to the adjacent portion of the sheet, wherein the improvement comprises, said plastic sheet having a substantially horizontal wooden reinforcing member of rectangular section extending above an extended portion of said shelf, said shelf portion of said sheet formed with an integral rectangularly shaped loop portion folded over and completely around said reinforcing member with opposite sides of the fold in substantially flat contact over a substantial area between said reinforcing member and said shelf to form in cross section an upper flange portion of said flanged beam, said integral loop portion extending up along said line generally perpendicular to said extensive area of said shelf portion to provide a front, said sheet extending from said loop portion beneath the shelf portion to form an integral shelf and shelf front, said shelf portion being formed by the spacing of two portions of said plastic sheet, and polyurethane foam insulation filling the space between said two portions to form in cross section a lower flange portion of said flanged beam.