Method of molding a vehicle door panel with a soft arm rest

United States Patent m

Kornylo

[54] METHOD OF MOLDING A VEHICLE DOOR PANEL WITH A SOFT ARM REST

[75] Inventor: Walter P. Kornylo, Livonia, Mich.

[73] Assignee: Atoma International Inc.,

Newmarket, Canada

[21] Appl. No.: 51,543

[22] Filed: Apr. 26,1993

[51] Int. CI.* B29C 67/22

[52] U.S. CI 264/46.8; 264/46.4;

264/46.6

[58] Field of Search 264/46.4, 46.7, 46.8,

264/511, 257, 46.6

[56] References Cited

U.S. PATENT DOCUMENTS

4,740,417 4/1988 Tornero 264/511

4,766,025 8/1988 Sanok et al 264/46.8

4,810,452 3/1989 Taillefert et al 264/46.4

4,923,539 5/1990 Spengler et al 156/79

5,037,591 8/1991 Rohrlach et al 264/46.8

5,082,609 1/1992 Rohrlach et al 264/46.4

5,091,031 2/1992 Strapazzini 264/46.8

5,236,534 8/1993 Noguti et al 156/245

FOREIGN PATENT DOCUMENTS

0411376 2/1991 European Pat. Off. 264/46.8

55-140526 11/1980 Japan 264/46.8

58-029633 2/1983 Japan 264/46.8

60-189432 9/1985 Japan 264/46.8

[ii] Patent Number: 5,387,390 [45] Date of Patent: Feb. 7, 1995

61- 297120 12/1986 Japan .

62- 009942 1/1987 Japan 264/46.8

Primary Examiner—Allan R. Kuhns

Attorney, Agent, or Firm—Cushman, Darby & Cushman

[57] ABSTRACT

A method of making an interior panel of a vehicle door having an exterior surface which is to face toward the interior of the vehicle when installed therein. The method includes the steps of heating a laminate sheet comprising (1) an outer layer of vinyl sheet and (2) a layer of relatively soft foamed material bonded thereto and vacuum forming the heated laminate sheet in a vacuum mold component oriented so that an arm rest portion of the laminate sheet is the vinyl sheet surface thereof engaged with the mold surface arm rest portion. Next, a preformed pad of foamed elastomeric material having a density in the range of 30 to 45 pounds per cubic foot is mounted on the opposite surface of the arm rest portion of the heated laminate sheet. Thereafter a foamable polyurethane material embedded within a reinforcing mat is heated and cured while all of the mold components to form a panel which includes (1) a substrate defining the opposite surface thereof, (2) an upwardly facing arm rest portion defined on its exterior surface by the vinyl sheet and backed up therebelow by the layer of relatively soft foamed material and the pad of foamed elastomeric material.

7 Claims, 2 Drawing Sheets

METHOD OF MOLDING A VEHICLE DOOR
PANEL WITH A SOFT ARM REST

This invention relates to vehicle door panels and 5 more particularly to improvements methods for making vehicle door panels relating to the provision of arm rest portions on the surface thereof which face the interior of the vehicle when installed therein.

BACKGROUND OF THE INVENTION 10

There are two different methods for making panels which serve as background for the present invention, both of which result in a somewhat similar panel construction. The difference is that one method is capable 15 of building into the panel more softness by including larger amounts of foamed material. Basically, this softer configuration is used in the more expensive luxury cars, whereas the other method is used basically in the large majority of other vehicles. 20

The method of making the luxury panel is essentially a two-stage process. In the first stage of the process, a substrate which is in the form of the panel is made by placing a fiberglass reinforcing mat in the lower half of a two-part mold and then filling the lower half of the 25 mold with a foamable material such as liquid polyurethane capable of being cured into a foamed condition. After the foamable material has been inserted into the lower half of the mold, the upper half is moved down and then the foamable material is cured under heat to 30 complete the substrate which is fairly rigid. In the second stage of the process, the substrate molded in the first stage is placed in the upper half of a second twopart mold. The lower part of the mold is in essence a vacuum mold. The second stage procedure is begun by 35 moving a heated sheet of imperforate vinyl over the bottom part of the mold and then drawing by vacuum the heated sheet into the mold so that the three-dimensional configuration is formed on the vinyl. After the vinyl has been moved into engagement with the mold 40 by the vacuum source, an amount of foamable material such as liquid polyurethane is then injected into the mold on top of the vinyl and thereafter the upper part of the mold which contains the substrate is then moved into cooperating relation with the lower part and the 45 foamable material is cured into a relatively soft foamed condition.

The other more economical process is essentially a one-stage process which utilizes a two-part mold, the lower part of which again is a vacuum mold for the 50 vinyl exterior sheet of the door panel to be made. In this case, the vinyl comes as the outer layer of a laminate which includes a layer of foamed material bonded thereto. The laminate is initially heated and then vacuum-drawn into the lower part of the mold. Next, a mat 55 of fiberglass or similar reinforcing is placed inside the laminate vacuum adhered to the lower mold and, thereafter, a liquid polyurethane is added to the lower mold part over the vacuum-held laminate. The upper mold part is then closed and essentially a relatively rigid 60 substrate is molded integrally with the vinyl laminate. In this process, it is not possible to provide much thickness and softness in the foam that is laminated with the vinyl or at least not as much as can be used in the second step of the two step process. 65

One area where the difference in softness is particularly noticeable is in the arm rest portion of the panel. There is a need in the more economical process to im

2

prove the softness of the arm rest portion in a cost effective manner.

SUMMARY OF THE INVENTION

An object of the present invention is to fulfill the need expressed above. Applicant has found that the objective can be achieved by the simple expedient of mounting a foamed pad of elastomeric material within the arm rest area of the laminated sheet after it has been vacuum formed within the vacuum forming mold part, provided the foamed rubber pad has certain softness-hardness characteristics. Applicant has found that where the foamed rubber pad utilized is too soft, it becomes compressed during the substrate molding procedure so that when the thus formed panel is removed from the mold assembly after the substrate has been molded, the compressive forces imparted to the pad during the pressure molding procedure are sufficient to cause the portion of the laminated vinyl defining the upper surface of the arm rest to bulge outwardly and present an unwanted distorted shape once the molding pressure is relieved from the vinyl surface as by removing the panel from the mold assembly. One the other hand, if the foamed pad is made hard enough to clearly avoid this compressive effect, it is too hard to provide the desired improved softness to the arm rest portion of the panel. The method of the present invention which obviates both the too soft compressive effect and the too hard effect includes the steps of heating a laminate sheet comprising (1) an outer layer of vinyl sheet and (2) a layer of relatively soft foamed material bonded thereto, vacuum forming the heated laminate sheet in the vacuum mold component oriented so that an arm rest portion of the laminate sheet is the vinyl sheet surface thereof engaged with the mold surface arm rest portion, mounting a preformed pad of foamed elastomeric material having a density in the range of 30 to 45 pounds per cubic foot on the opposite surface of the arm rest portion of the heated laminate sheet, placing a reinforcing mat over the mold surface defining the exterior surface of the panel and the heated laminate sheet vacuum formed thereon, adding foamable polyurethane material onto the reinforcing mat, and heating and curing the foamable polyurethane material while all of the mold components are in cooperating relation so as to form a panel which includes (1) a substrate defining the opposite surface thereof, (2) an upwardly facing arm rest portion defined on its exterior surface by the vinyl sheet and backed up therebelow by the layer of relatively soft foamed material and the pad of foamed elastomeric material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a completed vehicle door panel constructed in accordance with a method of the present invention;

FIG. 2 is a sectional view of a vacuum mold part showing a step in the method according to the present invention;

FIG. 3 is a sectional view similar to FIG. 2 showing the completion of the vacuum forming step of the method;

FIG. 4 is a sectional view similar to FIG. 2 showing the start of the substrate forming step of the method; and

FIG. 5 is a sectional view of the mold assembly including the vacuum mold part shown in FIGS. 2, 3 and