METODO DI CONTROLLO DELLA TENSIONE DI INSTALLAZIONE DI UNA CINGHIA IN UNA TRASMISSIONE A CINGHIA DI UN MOTORE A COMBUSTIONE INTERNA PER UN AUTOVEICOLO, TRASMISSIONE A CINGHIA RELATIVA, E TENDITORE BI-BRACCIO PER TALE TRASMISSIONE

A method of adjusting the installing tension of a belt (3) in a drive (1) of an internal combustion engine (2), in which a two-arm tensioner (7; 60) comprises an anchoring body (8) for anchoring to the engine (2), a pair of arms (9, 10) provided with respective pulleys (16, 17) adapted to act on respective strands of the belt (3) with the action of a spring (18), the method comprising the steps of: mounting the tensioner (7; 60) to said engine (2) with the arms (9, 10) blocked in a predetermined load condition of the spring (18) by means of releasable blocking means (45, 46), fitting the belt (3) with said movable member (16; 8) arranged at a position of minimum tensioning of the belt (3); adjusting the position of the movable member (16; 8) to progressively increase the tension of said belt (3) until a nominal installing tension is reached, in which the arms (9, 10) are balanced under the loads exerted by the spring (18) and the belt (3); blocking the movable member (16; 8) of the tensioner (7; 60) at the position corresponding to the nominal installing tension; and releasing said blocking means (45, 46).