Division 7.3

In the case of mechanical brakes, the following shall be determined:

1. 7.3.1.

   Reduction ratio i_g (see Figure 4 of Appendix 1);

2. 7.3.2.

   Force P* for braking torque M*;

3. 7.3.3.

   Torque M* as a function of the force P* applied to the control lever in mechanical-transmission systems.

   The rotational speed of the braking surfaces shall correspond to an initial vehicle speed of 30 km/h in the case of Class C1 vehicle, 40 km/h in the case of Class C2 vehicle, 60 km/h in the case of Class C3 vehicle, when the towed vehicle moves forward and 6 km/h when the towed vehicle moves rearward. The following shall be derived from the curve obtained from these measurements (see Figure 6 of Appendix 1):

   1. 7.3.3.1.

      The brake-retraction force Po and the characteristic value ρ when the trailer moves forward;

   2. 7.3.3.2.

      The brake-retraction force P_or and the characteristic value ρ_r when the towed vehicle moves rearward;

   3. 7.3.3.3.

      Maximum braking torque M_r up to the maximum permissible travel s_r when the towed vehicle moves rearward (see Figure 6 of Appendix 1);

   4. 7.3.3.4.

      Maximum permissible travel at the brake control lever when the towed vehicle moves rearward (see Figure 6 of Appendix 1).