IEC 60471:2020 pdf download

IEC 60471:2020 pdf download.Clevis and tongue couplings of string insulator units – Dimensions
1 Scope
This international standard applies to string insulator units of the cap and pin type and also of the long rod type as well as the fittings used with such insulators. The object of this document is to define the dimensions of a series of clevis and tongue couplings to permit the assembly of insulators or fittings supplied by different manufacturers. NOTE 1 IEC 60305 gives the coordination between the standardized dimensions of Table 1 and the strength classes of cap and pin insulator. IEC 60433 gives the coordination between the standardized dimensions of Table 2 and the strength classes of long rod insulators. NOTE 2 If the dimensions given in Table 1 are not sufficient, higher strength classes are given in IEC 60305.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-471 :2007, International Electrotechnical Vocabulary (IEV) – Part 471: Insulators IEC 601 20:2020, Ball and socket couplings of string insulator units – Dimensions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 3.1 clevis and tongue coupling female part of a clevis and tongue coupling with a U-shaped opening into which the tongue coupling can be fitted Note 1 to entry: A clevis contains two holes through which the coupling pin may pass to couple the two components. 3.2 clevis female part of a clevis and tongue coupling with a U-shaped opening into which the tongue coupling can be fitted Note 1 to entry: A clevis contains two holes through which the coupling pin may pass to couple the two components. 3.3 tongue male part of a clevis and tongue coupling with a tongue-shaped extremity which fits into the U-shaped opening of the clevis and which contains a hole through which the coupling pin may be passed 3.4 coupling pin rigid pin which passes through the holes in the clevis and tongue to couple them together Note 1 to entry: On one end, the coupling pin has a stud head and on the other a security device (e.g. split pin) is placed to hold the pin in its place.
4 Couplings
4.2 Couplings with limited movement Couplings according to Figure 1 , and Table 1 , for which a limited movement of the tongue in the clevis needs to be assured. This type of coupling is used for cap and pin insulators to ensure that no contact is possible between the insulating parts of two consecutive insulators. A rectangular shape is recommended for the tongue. These couplings are designated by the nominal diameter, expressed in millimetres, of the coupling pin followed by the letter C. 4.3 Couplings with unlimited movement Couplings according to Figure 2, and Table 2, for which the movement of the tongue in the clevis is not limited. This type of coupling is used for long rod insulators. These couplings are designated by the nominal diameter, expressed in millimetres, of the coupling pin followed by the letter L.4.4 Designation of couplings Clevis and tongue coupling are designated by the nominal diameter, expressed in millimetres, of the coupling pin which connects the clevis and tongue. A designated coupling is defined by the dimensions of the clevis, of the tongue and of the coupling pin. The Figure 1 and Figure 2 giving the diameter of the coupling pin is followed by the letter C in the case of couplings for cap and pin insulators or by the letter L in case of long rod insulators. Any confusion shall be avoided between the designation mentioned above referring to clevis and tongue couplings and the ball and socket couplings which are designated by nominal pin diameter which, in certain cases, may be followed by the letter A or B (see IEC 601 20), Therefore, the type of coupling shall always be precisely designated.