Les poulies dans les CG-4A étaient d'une utilité majeure pour le bon fonctionnement de toutes les commandes du planeur. En effet les Waco étaient entièrement équipés de commandes manuelles qui depuis le poste de pilotage permettaient aux pilotes ou co-pilotes de diriger le planeur par le principe de câbles de différentes tailles et longueurs qui depuis le cockpit allaient aussi bien commander les freins, les aerofreins, les derives de queue etc.... ces cables étaient tous guidés vers leur destination par plus de 90 poulies de 5 tailles différentes. Conçues en bakelite toutes montées sur roulements à billes. Les principaux fabricants, hormis quelques petites usines tels que MP bakelite ou la général Bakelite étaient la société Westinghouse qui fut également connue pour la fabrication des casques légers et la fameuse Formica qui après guerre sera connue dans toute l'Europe du renouveau pour ses fameux meubles à revêtements de cuisine et de toutes les pièces de la maison.. voici ci dessous des exemplaires de poulies retrouvées dans des planeurs atteris à La Motte .
Pulleys in the CG-4A gliders were the key element in the movement of the glider. Pulleys activated and moved in unison hundreds of meters of cables in every action required by the glider pilots to control the glider. The pilots manual controls of pulling, pushing, or turning were all managed by pulleys from within the cockpit, wings, tail and even the landing gear.
These little ball bearing mounted pulleys were of 4 different sizes made from Bakelite. Bakelite sometimes spelled Baekelite is an early plastic. It was developed by the Belgian-American chemist Leo Baekeland in New York in 1907. One of the first plastics made from synthetic components. Baekeland started semi-commercial production of his new material in his home laboratory, marketing it as a material for electrical insulators. By 1910, he was producing enough material to justify expansion. He formed the General Bakelite Company as a U.S. company to manufacture and market his new industrial material.
Bakelite was used for its electrical non-conductivity and heat-resistant properties in electrical insulators, radio and telephone casings and such diverse products as kitchenware, jewelry, pipe stems, children's toys, firearms, ashtrays, button clothes. When the war started factories concentrate their effort to provide for the US Army.
The Pulleys were manufactured by two main factories, Formica and Westinghouse Electric, as well as three smaller factories. Westinghouse Electric was founded by George Westinghouse in Pittsburgh, Pennsylvania in 1886. During WWII Westinghouse was one of those big contributors to the many items used by the U.S government, such as helmets liners and other airplane parts including the famous pulley for the CG-4A glider.
However, the most important manufacture was Formica. Formica laminate was invented in 1912 by Daniel J. O'Conor and Herbert A. Faber, while working at Westinghouse, resulting in a patent grant on 1 February 1913. They originally conceived it as a substitute for mica used as electrical insulation, made of wrapped woven fabric coated with Bakelite thermosetting resin, then slit lengthwise, flattened, and cured in a press. O’Conor and Faber left Westinghouse to start a business creating products based on this process. The company began operations on 2 May 1913, and was immediately successful. By September, Formica Products Company employed eighteen people trying to fill the demand for electrical parts for Bell Electric Motor, Ideal Electric, and Northwest Electric. During World War II it manufactured "Pregwood" plastic-impregnated wooden aeroplane propellers and bomb parts but also the CG-4A WACO gliders pulley.
Merci à Patricia Overman et Charles Day. Association des pilotes de planeurs américains de la seconde guerre mondiale pour la publication de notre étude sur leur page internet.