English to Italian Law/Patents Patents meccanica

Non mettetevi a ridere: sto traducendo un brevetto su un'apparecchiatura per la circoncisione di un pene.
Non so come tradurre "buckling device". Compare in queste frasi:
" The buckling device comprises a screw on one end of the fixture device and a linear threaded hole on the other end of the fixture device".
"A hook and a linear groove may be provided on each side of a buckling device located on each open end of the fixture device, and a protective cover may be provided over the buckling device, minimizing the risk of the buckling device opening due to, for example, a penile erection."
"The fixture device comprises at least one hinged connection, allowing the fixture device to close around the penis, where it may then be secured by a buckling device incorporated into the fixture device structure."