Abstract: A method of and apparatus for molding hollow items using the resin transfer molding technique in such a manner that the resin is more uniformly distributed about and along the molding region of the mold. This is accomplished by installing oppositely spaced grooves in the mold and injecting resin directly into these grooves. Upon such injection, the resin travels along and fills the groove (by taking the path of least resistance) before such resin is squeezed or forced out a minute gap that exists between the molding surfaces and into the molding region of the mold. As such resin is being forcibly injected into the cloths in the mold, a vent permits any air displaced from the cloths by the resin to be released. Such resin injection and mold venting occurs until such time that no more air is vented and instead 100% resin is being discharged from the mold. Upon this occurrence, further resin injection is curtailed and the resin previously injected is allowed to harden and cure.

Abstract: A static efficiency enhancer for an axial fan having a hub and a plurality of blades extending radially outward from the hub, the enhancer comprising a plurality of airfoils connected to the hub and extending outwardly therefrom to provide additional air velocity at the periphery of the hub.

Abstract: A fan blade comprising a body having a tip end and an in-board end is configured with first and second fin portions that extend along the trailing edge of the body of the fan blade. The first fin portion extends from the in-board end of the fan blade along the trailing edge toward the tip end, while the second fin portion extends from the tip end of the fan blade along the trailing edge toward the in-board end. Both the first and second fin portions extend outwardly from the trailing edge of the body at an angle to this trailing edge. Generally a slot or gap would exist between these first and second fin portions and both such fin portions would have a tapered width which narrows in the direction of the tip end. Additionally, the width of the first fin portion would be greater than the width of the second fin portion. Furthermore, the two fin portions may or may not be co-planar in order to optimize air flow.

Abstract: A static efficiency enhancer for an axial fan having a hub and a plurality of blades extending radially outward from the hub, the enhancer comprising a plurality of airfoils connected to the hub and extending outwardly therefrom to provide additional air velocity at the periphery of the hub.

Abstract: A width extender is used to modify existing fan blades in order to enable them to rotate at slower speed thereby reducing the noise associated with them while at the same time maintaining a proper work efficiency. The width extender is fixably connected along the trailing edge of an existing fan blade by adhesive bonding, riveting, welding, or otherwise. Width extender can be made of an extruded plastic material, preferably nylon, or it can be constructed of the same material as the fan blade itself. Ideally, the width extender would increase the width of the fan blade by 20% to 25%. Additionally, this width extender would have a uniform length so as to uniformly increase the entire width of the fan blade.

Abstract: A molded hollow fan blade in which a preform (preferably constructed of glass fibers) is used to support the upper multiple layers of to-be-impregnated cloth within a mold. As resin is injected into the mold, the cloth and the preform become impregnated (this resin dissolving the temporary resin binder holding the preform together) thereby bonding the two together to form a single unit during the molding operation.

Abstract: A protection element containing a spring steel strip is bent to have a greater curvature than the curvature at the leading edge of a fan blade. This protection element is then fixed to the leading edge of the fan blade over an area of maximum erosion. Rubber or another elastomer can be extruded over the strip before or after it is fixed to the fan blade or the strip can incorporate an outer hardened layer to resist erosion. Attachment of the strip to the blade is advantageously accomplished using rivets or screws at spaced locations along the blade and at the leading edge of the blade.

Abstract: A protection element containing a spring steel strip is bent to have a greater curvature than the curvature at the leading edge of a fan blade. This protection element is then fixed to the leading edge of the fan blade over an area of maximum erosion. Rubber or another elastomer can be extruded over the strip before or after it is fixed to the fan blade or the strip can incorporate an outer hardened layer to resist erosion. Attachment of the strip to the blade is advantageously accomplished using rivets or screws at spaced locations along the blade and at the leading edge of the blade.

Abstract: A method of molding a hollow fan blade in which a preform (preferably constructed of glass fibers) is used to support the upper multiple layers of to-be-impregnated cloth within a mold. As resin is injected into the mold, the cloth and the preform become impregnated thereby bonding the two together to form a single unit during the molding operation.

Abstract: There are disclosed a blade for use as part of an axial flow fan and a method of forming such a blade wherein a large concentration of silica particles are molded into the leading edge of a hollow, one-piece molded body which includes a core of reinforced, thermosetting resin having relatively low abrasion resistance.

Abstract: There is disclosed an axial flow fan having blades which may be rotated about their axes to permit their pitches to be adjusted and which may be moved in a radial direction to adjust the clearance between their tips and the fan ring in which they rotate.

Abstract: There is disclosed an axial flow fan having blades which are made up of metallic inner portions attached to the hub of the fan, and outer plastic portions whose inner ends are secured to the outer ends of the metallic portion. The plastic portions are hollow and have an exterior surface of air foil cross section, and seal discs on one side of the hub extend outwardly therefrom to approximately the intersection of the metallic and plastic portions.

Abstract: There is disclosed a bearing assembly comprising first and second bearing elements arranged in axially spaced relation about a shaft which oscillates about its axis through a relatively small angle, the bearing element which sees thrust loading from the shaft comprising a radially inner bearing part having a conically shaped outer surface which is slidable over a similarly shaped inner surface of the outer bearing part.