Patent ID: 7992540

Claim:
A decompression braking device in an endothermic engine ( 1 ) of a type comprising a head with at least one lever axle ( 2 ) on which a plurality of eccentric bushings ( 31 ) of a corresponding plurality of levers ( 3 ) are rotationally and eccentrically mounted, each lever ( 3 ) being provided with a tappet ( 4 ) for actuating one or more exhaust valves ( 5 ), and a camshaft ( 30 ) actuating said plurality of levers ( 3 ), the device comprising an actuating member ( 6 , 61 ) mounted externally to said lever axle ( 2 ) and connected to said bushings by means of linkage means ( 8 , 9 , 10 ), an arrangement being such that a respective rotation of said bushings ( 2 ) by a predetermined angular value, with consequent displacement of a hinging axis of said levers ( 3 ), corresponds to each excursion of said actuating member ( 6 , 61 ); wherein said linkage means comprise a plurality of arms ( 9 ) arranged on said bushing ( 31 ), a plurality of pins ( 8 ) arranged on said actuating members ( 6 ), and a corresponding plurality of connection elements ( 10 ) each of which being hingingly mounted between an arm of said plurality of arms ( 9 ) and a pin of said plurality of pins ( 8 ), the arrangement being such that said plurality of arms ( 9 ), said plurality of pins ( 8 ), and said plurality of connection elements ( 10 ) form a four-bar linkage.