Abstract: A mandrel is fitted with a molded sleeve of low-temperature alloy for forming a rigid bulge along the surface of the mandrel. The sleeve is shaped to define the. internal surface of the shell at the bulge. After the mandrel has been so modified with the low-temperature alloy sleeve, it is wrapped with composite cloth containing any thermosetting resin. These resins heat to a known temperature, and permanently set when cured at the set temperature. The curing temperature of the prepreg cloth composite material is lower than the melting point of the low temperature alloy. After curing, the temperature in the curing oven is raised above the cure temperature until it reaches the melting point of the low-temperature alloy, and the alloy liquifies and drains out the drain passageways provided in the mandrel without melting the thermoset resin binder in the fiber cloth as well as leaving the bulge formed by the composite cloth in the shell without obstructing the removal of the mandrel.

Abstract: A mandrel is fitted with a molded sleeve of low-temperature alloy for forming a rigid bulge along the surface of the mandrel. The sleeve is shaped to define the internal surface of the shell at the bulge. After the mandrel has been so modified with the low-temperature alloy sleeve, it is wrapped with composite cloth containing any thermosetting resin. These resins heat to a known temperature, and permanently set when cured at the set temperature. The curing temperature of the prepreg cloth composite material is lower than the melting point of the low temperature alloy. After curing, the temperature in the curing oven is raised above the cure temperature until it reaches the melting point of the low-temperature alloy, and the alloy liquifies and drains out the drain passageways provided in the mandrel without melting the thermoset resin binder in the fiber cloth as well as leaving the bulge formed by the composite cloth in the shell without obstructing the removal of the mandrel.

Abstract: A strong, lightweight blade provided for use on wind turbines utilizes an interior reinforcing strut which extends part-way out the blade and consists of telescoped steel pipes welded to one another and mounted at their root ends to a steel cuff. A carbon graphite spar slips over the telescoped tubes and inside the cuff and extends radially outwardly substantially to the end of the blade. A rigid skin which is airfoil-shaped in all of its cross-sections attaches to the spar and spans from the root of the spar to the distal tip of the blade, defining the wind-driven surfaces of the blade.

Abstract: A sealed, oil-filled journal is provided which includes two axially-spaced ball race areas in the preferred embodiment, and which incorporates an axially expanding pressure ring disposed between an internal annular rib and the angular contact ballbearing ring in one of the ball race chambers. The pressure ring maintains generally constant force against all of the bearings in the spaced ball race chambers so that the combination of the immersion in oil of all the bearings in the journal, and the maintenance of the constant pressure on the bearing elements to prevent their getting loose, minimizes brinelling and produces a jounral that has a very long life span.

Abstract: A circular mail singulator is provided having a continuous spiral baffle which is disposed immediately above a rotating annular table with a frictional top surface, there being a central cone for the delivery of envelopes into the inner convolution of the spiral and a linear conveyor tangential to the outermost convolution to receive envelopes delivered therefrom and, without interrupting the envelope speed, deliver the envelopes into a stamp cancelling machine.