A gripping device for shells that includes a pair of jaws intended to clamp a shell, each jaw being able to pivot towards a closed position obtained by applying the top end of each jaw to the shell. A locking means links the top ends of the jaws and includes two connecting rods and a central segment linking these connecting rods. The connecting rods are articulated relative to the jaws by a first articulation and by a second articulation to the central segment. A spring links each first articulation to a central point of the segment. A movable stop situated above the locking means is capable of pushing the locking means downwards until it is below an unstable equilibrium position of the locking means.