PCT No. PCT / FR97 / 01184 Sec. 371 Date Jun. 17, 1998 Sec. 102(e) Date Jun. 17, 1998 PCT Filed Jul. 3, 1997 PCT Pub. No. WO98 / 01751 PCT Pub. Date Jan. 15, 1998The subject of the invention is a device for manufacturing a composite
yarn formed by the combination of continuous glass filaments and continuous filaments of a
thermoplastic organic substance, comprising, on the one hand, at least one
bushing which is fed with glass, the
lower face of which is provided with a multiplicity of orifices from which a multiplicity of glass filaments is drawn, and is associated with a
coating device and, on the other hand, at least one
extrusion head fed with a molten
thermoplastic organic substance, the
lower face of which is provided with a multiplicity of orifices from which a multiplicity of organic filaments is drawn, the said head being associated with a drawing device comprising at least two drums and with a venturi device which projects the organic filaments into the sheet formed by the glass filaments, and means, common to the
bushing and to the
extrusion head, which enable the composite
yarn to be assembled and drawn, for example by a winding device such as a
bobbin winder provided with spindles, in which an optical device for detecting the sheet of
thermoplastic filaments running through a defined region is arranged between the drum-type drawing device and the venturi device, the said optical device being connected to a circuit which controls the speed of rotation of at least one of the drums.