Abstract: A two-staged or sequential reaction injection molding (RIM) method of manufacturing a glass fiber mat reinforced plastic part having at least one appearance surface in which a high viscosity RIM material and a low viscosity RIM material are sequentially injected into a mold cavity containing at least one reinforcing member of a glass fiber mat.

Abstract: A vehicle door includes an outer panel and an inner panel of molded synthetic resin construction. The inner panel has 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 is embedded in the upper portion of the inner panel and has leg portions extending downwardly 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. The tubular member is a continuous hollow tube formed to have varying cross sectional shape along the continuous length to fit within the shape of the window frame.

Abstract: A mechanism for forming threads in injection molded parts includes a core member having a threaded end which is moved into and out of a mold cavity. The core member is slidably and rotatably mounted on a support and is driven by a motor through a first lost motion rotatable connection. The core member is moved linearly upon rotation thereof into the mold cavity by a lead screw member which is coupled to the core member through a second lost motion connection and threadably mounted in the support.