Attachment In Multi-Leg Chain Suspension Gear; Symmetrical Loading; Asymmetrical Load; Balancing Rocker - Pfeifer HIT GK 8 Traducción Del Manual Original

4.2 Attachment in multi-leg chain
suspension gear
For multi-leg chain suspension gear, angles of inclination
of less than 15° should be avoided and angles of inclina-
tion greater than 60° are not permissible. To exclude
overloads, the number of chain legs that may be cate-
gorised as load-bearing should be checked by a qualified
person for each lifting procedure.
In general, in the four-leg suspension, three or, depending
on the nature of the load, two chain legs are assumed as
load-bearing. In the three-leg suspension three or two
chain legs are assumed as load-bearing, depending on
the nature of the load. Moreover, the attachment method
can have an influence on how many chain legs may be
loaded. When using mobile cranes, in general only two
chain legs are considered as load-bearing. These speci-
fications are only valid for symmetrical loads. Amongst
other things, EN 818-6 and DGUV rule 109-017 along
with applicable country-specific regulations should be
observed. In the case of asymmetrical loads, the working
load limit must be reduced.

4.3 Symmetrical loading

For this application, it is important to ensure a symmet-
rical loading of the chain legs. This is the only way to
guarantee that the weight of the load to be lifted is
uniformly distributed to all of the chain legs. The load
can still be considered symmetrical when all the follo-
wing conditions are met:
• The load amounts to less than 80 % of the rated
working load limit
• The angles of inclination of all chain legs are not
less than 15°
• The angles of inclination of all chain legs are equal or
differ from one another by a maximum of 15°
• In the case of three- and four-leg chain slings the
angles corresponding to each other on the attachment
plane deviate by a maximum of 15°

4.4 Asymmetrical load

In the case of an asymmetrical load of the chain legs,
the working load limit must be reduced. In case of
doubt, only one chain leg is assumed to bear the entire
weight of the load. Corresponding information can be
found, for example, in the working load limit tables on
page 5. Please also refer to DGUV regulation 109-017.
Chain slings 12/2021 / Subject to change!
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Asymmetric load distribution is always to be expected
when
• the load is inelastic (e. g. concrete parts, castings,
short beams, etc.)
• the position of the centre of gravity is not known
• the load is unevenly shaped
• different angles of inclination ß occur
Examples of asymmetry:
Fig. 4.4.1: The majority of the load
will be lifted by one chain leg
Fig. 4.4.3: The majority of the load
will be lifted by the single leg with
the smallest angle of inclination (ß

4.5 Balancing rocker

Using a balancing rocker for a symmetrical load of the
chain legs in the four-leg suspension means that all four
chain legs are considered load-bearing. The angle of
inclination of the rocker must not exceed 15°. This does
not apply for an asymmetrical load distribution!
Fig. 4.5.1: Balancing rocker
Fig. 4.4.2: The majority of the load
will be lifted by two chain legs
)
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