but left hand side of the page in fig4 as the tube 31 of the brake shoe interface 30 is on the shaft 22 the brake shoe interface 30 will translate in the same direction as the shaft 22 as the tube 31 forms a rotational joint with the shaft 22 the movement will be transmitted to the brake shoe interface 30 in such a way that same will move the brake shoe 12 in normal unconstrained fashion outwardly relative to the back plate 11 in direction f2 on the other hand the brake shoe interface 40 will convert the rotational movement of the link 29 into a displacement of its respective shoe 12 toward the right hand side in fig4 the rotational joints formed between the brake shoe interface 40 and both the link 29 and the shoe 12 allow the generally unconstrained transmission of movement from the link 29 to its respective shoe 12 thereby moving the shoe 12 outwardly and into braking contact with the wheel drum although one specific configuration has been shown in fig1 5 it is considered to use other mechanisms to transmit the force from the safety brake system to the shoes 12 for instance instead of being integrally connected to its respective shoe 12 the brake shoe interface 30 may be offset from the axis of the shaft 22 and may be pivotally connected to its respective shoe 12 and to the link 29 e g diametrically opposed to the connection point between the link 25 and the brake shoe interface 40 hence by the release of the cable tension.