During pre-flight control docking in fall 1974 the guide pins and sockets were replaced with modified ones (see Figure 3.20). The replacement was done only on the Apollo APDAs, in which the replacement could be made without disassembly of the assemblies. Tn the modified structure, jamming of the cylindrical pin was eliminated by minimizing the cylindrical part of the socket, and jamming in the rotating socket was eliminated by introduction of undercutting in the modified pin. When there are built-in hydraulic connections for the system of thermal regulation the sockets may not be shortened, and their jamming is eliminated because there are no sufficient lateral forces (exceeding the forces of the springs in the socket), smaller angular errors, and consequently, maximum angles of rotation of the socket. The connectors which are connected by the docking mechanism drive (see section 2.1.3) differ in their long course (10-50 mm) and small force (0.2-0.3 kN). Thermal regulation system connectors and fuel and oxidizer supply connectors are similar. Hydraulic connectors which are connected by the locks of the docking frame have not yet been used. The course needed to connect these connectors should not exceed the course of the latches, that is, 4-6 mm, and the force of connection should be significantly larger than for the first type of connectors. Thus, end seals should be used in the design of these connectors. Tn the construction of other elements which are installed on the end of the docking frame (sensors, plungers, etc.), one also considers the need for reliable compression. For example, in the APDA the plungers are made with double guides (Figure 3.21). When the plunger jams in the socket, the plunger may be compressed during displacement of the socket. Tt is also possible to create “destructible” (for a sufficient increase in the force of compression) plungers and sensors, etc. On the ends of the active and passive assemblies are several hundred bolts, pins, and other parts which are a potential danger in the connection of the docking frames if they protrude from the joint plane, for example, in spontaneous reversing of bolts Thus, units and parts should be installed in order to eliminate or substantially reduce the number of protruding fasteners.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==