20c the padlocking enabling member 130 has a disk 132 provided with a central bore 126 having the shape of two circumferentially offset superimposed squares and having a little larger size to obtain the above described large wrench effect disk 132 is provided on the periphery thereof with a raised cam profile portion 134 having an interruption or depression 136 engaging a padlocking enabling member in the form of a slider 138 fig1 a 16b 17a 17b 18a 18b and 19a 19b which can either enter in or come out from the slot 117 since it is positioned above the cam profile portion 134 or depression 136 when rotary handle 116 is in an open position and the underlying circuit breaker is properly open disk 132 of member 130 driven by any suitable mechanism connected to the circuit breaker is positioned with the depression 136 under the slider 138 which descends to the position depicted in the fig1 a and 16a at this time latch 150 can be driven into the handgrip 122 aligning the recess 152 with the window 154 and thus allowing the entry of the end 156 into slot 117 and thus the movement of a padlock member bow thereinto and the padlocking of the.