Abstract: It comprises a U-shaped bow (1), a handle (2) and two securing devices (3, 4) at both ends of the saw (5), each of the devices (3, 4) comprising a body (31) fitted with a longitudinal passage (32) enabling the control and centering of the saw (5), the body (31) comprising a tightening screw (33, 34) fitted perpendicularly to the passage (32) enabling the possibility of tightening the corresponding end of the afore-mentioned saw (5) in the passage (32).