An appliance for rapidly vibrating test tubes containing samples to be ground up, the appliance comprising an electric motor (12) for driving rotation of a disk (16) that is provided with an eccentric pin (17), the appliance being characterized in that the test tubes (23) are perpendicular to the eccentric pin and are held by a clamp (21) mounted on a support (20) that is substantially parallel to the eccentric pin, being connected to a fixed baseplate via a Cardan type hinge (15) having two mutually perpendicular axes of rotation (X and Y), one of which axes (Y) is substantially parallel to the eccentric pin (17) and connects the support (20) to the other axis (X) of the hinge (15) that prevents the support (20) from moving in rotation about a perpendicular axis (Z). The support (20) is connected to the eccentric pin (17) by a link (19).