APPAREIL POUR FORMER UNE LONGUE EXTREMITE LIBRE DE FIL LORS DE L'ENROULEMENT SUR UNE BOBINE

CET APPAREIL COMPORTE UN ARBRE 11 ENTRAINANT LA BOBINE EN ROTATION ACCOUPLEE, PAR UN EMBRAYAGE A FRICTION 13 A UNE JOUE DE TRANSFERT 7 MUNIE D'UN ORGANE DE SERRAGE DE L'EXTREMITE DU FIL, AU DEBUT DU BOBINAGE. UN MECANISME DEMULTIPLICATEUR 15, 16 ET 18 EST MONTE ENTRE L'ARBRE 11 ET LA JOUE DE TRANSFERT 7 ET ASSOCIE A UN EMBRAYAGE ELECTROMAGNETIQUE 17 DE SORTE QUE, LORSQUE CET EMBRAYAGE 17 EST EMBRAYE, LA JOUE DE TRANSFERT TOURNE LEGEREMENT MOINS VITE QUE LA BOBINE, CE QUI FORME UNE EXTREMITE LIBRE AYANT LA LONGUEUR DESIREE QUI EST DETERMINEE PAR LE NOMBRE DE TOURS EFFECTUES PAR LA BOBINE OU LA JOUE PENDANT QUE L'EMBRAYAGE EST EMBRAYE, AU DEBUT DU BOBINAGE. An apparatus for forming a long leading end in a wire wound on a reel in a winding machine comprising at least one power driven shaft for rotating a reel and a shifting flange positioned at one side of said reel. The shifting flange is provided with means for gripping the leading end of the wire when starting the winding of the wire on said reel. The apparatus comprises a gear mechanism coupled between the reel shaft (11) and the shifting flange (7) which gear mechanism rotates said shifting flange with a rotation speed lower than the rotation speed of the reel. The gear mechanism is provided with coupling means (17) for selectively connecting and disconnecting said gear mechanism and the shifting flange is coupled by means of a friction clutch so that said shifting flange slides on the reel shaft when the gear mechanism is connected but is driven by said reel shaft when the gear mechanism is disconnected. The gear mechanism is connected under a predetermined number of revolutions of the reel at the beginning of the winding on the reel in order to wind the leading end of the wire as one or several loops considerably larger than the wire windings on the reel and thereby to obtain a long free leading end in the wire wound on the reel.