Plastic motor vehicle door

A vehicle door comprising:

• an outer panel and an inner panel of molded synthetic resin construction, said inner panel having a structural lower portion concealed beneath the outer panel and an upper portion integral with the lower portion and defining a window frame surrounding a window opening, a tubular reinforcement member of generally inverted U-shape embedded in the upper portion of the inner panel and having leg portions extending downward from the upper portion and embedded in the structural lower portion so that the structural lower portion connects the leg portions of the upper portion, said tubular member being a continuous hollow tube formed to have varying cross-sectional shape along the continuous length.

A vehicle door comprising:

• an outer panel and an inner panel of molded synthetic resin construction, said inner panel having a structural lower portion concealed beneath the outer panel and an upper portion integral with the lower portion and defining a window frame surrounding a window opening, a tubular reinforcement member embedded in the upper portion of the inner panel, said synthetic resin of the upper portion being a reinforced reaction injection molded material providing a finished surface and the synthetic resin of the lower portion being a structural reaction injected molded material providing relatively high strength and unfinished surface.

A vehicle door comprising:

• an outer panel and an inner panel of molded synthetic resin construction, said inner panel having a structural lower portion concealed beneath the outer panel and an upper portion integral with the lower portion and defining a window frame surrounding a window opening, a tubular reinforcement member of generally inverted U-shape embedded in the upper portion of the inner panel and having leg portions extending downward from the upper portion and embedded in the structural lower portion so that the structural lower portion connects the leg portions of the upper portion, said tubular member being a continuous hollow tube formed to have varying cross-sectional shape along the continuous length, said synthetic resin of the upper portion being a reinforced reaction injection molded material providing a finished surface and the synthetic resin of the lower portion being a structural reaction injected molded material providing relatively high strength an unfinished surface, and a glass fiber mat spanning between the synthetic resins of the upper and lower portion and embedded therein to facilitate the bonding between the upper and lower portions.