levis and tongue couplings
IEC 60471-2020 pdf download.levis and tongue couplings of string Insulator units — Dimensions
Assemblages a chape et tenon des éléments de chaines d’isolateurs — Dimensions.
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 lIthe dimensions given In Table I 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 (1EV) — Part 471: insulators IEC 60120:2020, 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.isoorg/obp
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 I to entry: A davis 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.
4.1 General
Two coupling systems are recommended:
— Couplings with limited movement:
— Couplings with unlimited movement.
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 60120), Therefore, the type of coupling shall always be precisely designated.IEC 60471-2020 pdf download.