Abstract: A molding process, other than pultrusion, is used to manufacture composite ladder rails of non-uniform cross-sectional area and non-uniform strength throughout their lengths. Each ladder rail includes a structural fiber preform embedded in a cured polymeric resin. Fiberglass preforms are preferred because they are electrically non-conductive. Resin transfer molding processes, using either polyester or epoxy resins, are ideally suited for such manufacture. Vacuum-bagged, open-mold processes may also be used, as may be compression molding processes. Regions of the rails subject to greater stress during usage are strategically reinforced with additional structural fibers, and have greater cross-sectional area than regions subjected to lesser stress. The differential cross-sectional area permits the construction of ladders which are optimized for both strength and lightness of weight. Ladders of all types may be constructed with rails incorporating the invention.

Abstract: Protective laminate films protect an underlying windshield from damage due to impacting rocks and other debris. The laminate films generally include a substrate having a scratch resistant coating and an adhesive layer on opposing surfaces thereof. Each layer is transparent such that, when applied to a windshield, the laminate film does not impact a driver's visibility. Each layer may also be flexible so that the laminate films can be molded to a curved windshield. Generally, the scratch resistant coating protects the laminate films from scratching or other damage from impacting debris or from windshield wipers. The substrate provides structural integrity to the laminate films and may provide some impact dispersion. The adhesive layer, in addition to adhering the laminate films to the windshield, may also provide significant impact resistance that protects the windshield from cracks or chips due to impacting rocks or other debris.