A surgical device comprising: an elongate body defining a longitudinal axis ("X"), the elongate body having a proximal portion and a distal portion; a tool assembly pivotably coupled to the distal portion of the elongate body about a pivot axis ("Z"), the tool assembly defining a longitudinal axis ("Y") and pivotable between a non-articulated position in which the longitudinal axis of the tool assembly is aligned with the longitudinal axis of the elongate body and articulated positions in which the longitudinal axis of the tool assembly is misaligned with the longitudinal axis of the elongate body; a drive assembly including a flexible drive beam and a clamp member, the flexible drive beam having a proximal portion, a distal portion, a first side, and a second side, the distal portion supporting the clamp member, the flexible drive beam being movable through a predetermined stroke length from a retracted position to an advanced position to move the clamp member within the tool assembly a predetermined distance; and an articulation assembly including an articulation link and first and second pivot links (102, 104), the articulation link having a proximal portion and a distal portion, the first pivot link positioned adjacent the first side of the flexible drive beam and having a proximal portion pivotably coupled to the distal portion of the articulation link and a distal portion pivotably coupled to the tool assembly, the second pivot link positioned adjacent the second side of the flexible drive beam and having a distal portion coupled to the tool assembly, the first and second pivot links (102, 104) being engaged with the flexible drive beam to control a path of movement of the flexible drive beam as the flexible drive beam is moved between its retracted and advanced positions to maintain the predetermined distance of movement of the clamp member within the tool assembly constant in the non-articulated and articulated positions of the tool assembly, characterised in that the first pivot link includes a convex guide surface that is engaged with the first side of the flexible drive beam when the tool assembly is in the non-articulated position to define a deformed portion in the flexible drive beam. an elongate body defining a longitudinal axis ("X"), the elongate body having a proximal portion and a distal portion; a tool assembly pivotably coupled to the distal portion of the elongate body about a pivot axis ("Z"), the tool assembly defining a longitudinal axis ("Y") and pivotable between a non-articulated position in which the longitudinal axis of the tool assembly is aligned with the longitudinal axis of the elongate body and articulated positions in which the longitudinal axis of the tool assembly is misaligned with the longitudinal axis of the elongate body; a drive assembly including a flexible drive beam and a clamp member, the flexible drive beam having a proximal portion, a distal portion, a first side, and a second side, the distal portion supporting the clamp member, the flexible drive beam being movable through a predetermined stroke length from a retracted position to an advanced position to move the clamp member within the tool assembly a predetermined distance; and an articulation assembly including an articulation link and first and second pivot links (102, 104), the articulation link having a proximal portion and a distal portion, the first pivot link positioned adjacent the first side of the flexible drive beam and having a proximal portion pivotably coupled to the distal portion of the articulation link and a distal portion pivotably coupled to the tool assembly, the second pivot link positioned adjacent the second side of the flexible drive beam and having a distal portion coupled to the tool assembly, the first and second pivot links (102, 104) being engaged with the flexible drive beam to control a path of movement of the flexible drive beam as the flexible drive beam is moved between its retracted and advanced positions to maintain the predetermined distance of movement of the clamp member within the tool assembly constant in the non-articulated and articulated positions of the tool assembly, characterised in that the first pivot link includes a convex guide surface that is engaged with the first side of the flexible drive beam when the tool assembly is in the non-articulated position to define a deformed portion in the flexible drive beam.