which is adapted to cooperate with the rocker 66 it acts together with rocker 66 which is itself acted upon by a spring 74 which is lodged in the one eyed hole 58 guide 75 which is soldered onto the swinging door 12 is in the form of a flat piece of metal the guide is of the same thickness as the rocker 66 the guide has to both sides of tooth 76 grooves 77 and 78 which are adapted to receive the tooth 73 of the rocker the toothed rocker is arranged such that its rounded part 68 can cooperate with a wedge 80 which is of adjustable thickness and which is attached to the flange 18 by a screw 81 the thickness of the wedge may be adjusted by varying the number and or thickness of the small metal plates which comprise wedge 80 additionally it is arranged such that edge 69 of the rocker can cooperate with shoulder 82 which is likewise of adjustable thickness shoulder 82 is attached by a screw 84 to an angle plate 83 which is attached to the section 15 when the strong box or safe is closed it is in the position shown in fig1 portion 44 of sheet 43 is relatively parallel to flange 17 of section 15 while portion 45 of the said sheet is relatively parallel to flange 18.