TRONCONNEUSE A CHAINE

LA TRONCONNEUSE A CHAINE EST COMPOSEE ESSENTIELLEMENT D'UN CARTER MUNI DE POIGNEES POSTERIEURE 11 ET ANTERIEURE 14 ET D'UNE UNITE MOTRICE FIXEE AU CARTER, A LAQUELLE EST FIXE UN RAIL DE GUIDAGE AVEC UNE CHAINE DE SCIAGE 4 CIRCULANT AUTOUR DU RAIL. LE CARTER COMPORTE UN BRAS EN PORTE A FAUX 10 S'ETENDANT VERS L'AVANT, SUR LEQUEL L'UNITE MOTRICE REPOSE ET A L'EXTREMITE ANTERIEURE 24 DUQUEL LA POIGNEE ANTERIEURE 14 EST FIXEE. POUR AUGMENTER SA RESISTANCE A LA TORSION ET A LA FLEXION, LE BRAS EN PORTE A FAUX 10 A UNE SECTION DROITE EN FORME DE S ESSENTIELLEMENT RECTANGULAIRE, LE PROFILE A SECTION EN S ETANT COMPOSE DE PARTIES INFERIEURE 27, MEDIANE 28 ET SUPERIEURE 29 PARALLELES ENTRE ELLES, LES PARTIES INFERIEURE ET SUPERIEURE ETANT REUNIES A LA PARTIE MEDIANE PAR DEUX FLANCS 30, 31, RESPECTIVEMENT. LES FLANCS SONT DISPOSES DANS DES PLANS PARALLELES AU RAIL DE GUIDAGE. A motor-driven chain saw essentially includes a housing having a rear handle and a front handle and a drive unit attached to the housing. A guide bar for accommodating the saw chain for movement thereon is attached to the drive unit. The housing has an extension arm on the underside of the chain saw which extends to the front; the drive unit is seated on this arm and the front handle is attached to the front end of the arm. To increase torsional and bending strength, the extension arm has an S-shaped profile when viewed in cross section. The S-shaped profile has a substantially rectangular configuration and includes lower, middle and upper parts that are parallel to one another and are interconnected by two flanks. The flanks are located in planes that are parallel to the guide bar.