Fuente: WIPO "honey" A sickle bar apparatus for cutting vegetation and the like and having an elongated sickle bar member with an equalizing member located behind the sickle bar and joined to the sickle bar adjacent corresponding ends by way of arcuately pivotal end structures so as to form a reciprocating closed loop. Either by way of setting the spacing between of the end structures or by an adjusting mechanism for shortening the length of the equalizing member, or the like, the sickle bar is set to remain in a tensioned condition in the closed loop throughout its reciprocating strokes. Thus, at any instant during a reciprocating cycle of the sickle bar, the speed and the state of acceleration or deceleration of the sickle bar and equalizing means in the closed loop are the same but in opposite directions so as to provide a linear cancelling of vibrating forces, and the setting of the bar in tension is sufficient to prevent the bar from alternatively experiencing tension and compression.