bearings are used, for example, in the Apollo APDA. The lock was constructed such that the active clamp linked with the passive clamp due to spring action, and the clamps were separated, if necessary, by protrusion of the eccentric shaft of the active damp. During tightening the shaft moved 6-8* below the dead position, which insured stability in the tightened mechanism. The specially profiled plank has grooves and protrusions on the casing of the active clamp enter the grooves; this also prevented the active clamp from disengaging. In its extended position the clamp protruded above the plank and did not prevent free opening. The eccentric mechanism is simple in construction and insures a reasonable dependence between the rotating momentum and the tightening force (see Figure 3.4), since the maximum force is developed near the dead position of the eccentric shaft. To further reduce the rotating momentum on the lock shaft, that is, the loads on the drive and forces in the cable connection, one can use an additional spring mechanism in the lock. This spring should be compressed to the angle of rotation of the shaft in which the lock is not loaded, and to return its own energy to the place where the maximum load is on the lock. This construction makes it possible to reduce the size and mass of the drive with the cable connection. This construction was used in the Apollo APDA. The set of plate-like springs of the passive clamps in the assembly of the lock were compressed by a regulating nut, creating the force providing the minimal acceptable tightening of the joint. 3.3.3. Issues Regarding the Provision of Reliability and Safety As analysis done in section 2.3 has shown, the locks of the docking frame are the docking device mechanism whose failure is most dangerous (frequently a category I or IT failure). Thus, analysis of the reliability of the locks is given the most attention. For example, in the process of creation and preparation for flight in the Apollo-Soyuz project a document was prepared and subsequently confirmed, “Evaluation of Safety of the Locks of the Docking Mechanism.'' The general approach to the analysis of the reliability and safety of the
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