A locket comprises a connection pin, a lock bracket and a lock rod. A first end of the connection pin is fixed to a first connection. A notch is provided on a sidewall of a second end of the connection pin. The lock bracket is fixed to a second connection. The lock rod is rotatable within the lock bracket between an open position and a closed position. A groove is provided on a sidewall of a first end of the lock rod. The groove of the lock rod accommodates the second end of the connection pin passing through the second connection when the lock rod is open, such that the connection pin is moveable in an axial direction. The first end of the lock rod is accommodated within the notch of the connection pin when the lock rod is closed to prevent the connection pin from moving axially.