© 2019 Columbus McKinnon Corporation. All Rights Reserved
3
LHH-B P/N 192063327
REV. AA March 2019
GENERAL INFORMATION
The
Coffing LHH-B manual (P/N LHH680-6 Rev AA
)
and this supplement provide information for the safe
operation and maintenance of this hoist. All persons
operating or maintaining these hoists should be
familiar with the information contained herein and in
the O&M manual. Adherence to the precautions,
procedures, and maintenance practices described
should ensure long reliable operation
CAUTION
To safeguard against the possibility of personal
injury or property damage, follow the
recommendations and instructions of this manual.
This manual contains important information for the
correct installation, operation, and maintenance of
this equipment. All persons involved in the
installation, operation, and maintenance of this
equipment should be thoroughly familiar with the
contents of this manual. Keep this manual for
reference and further use.
WARNING
Using “Commercial” or other manufacturer’s parts to
repair the Coffing Hoists may cause load loss.
To avoid personal injury:
Use only COFFING supplied replacement parts.
Parts may look alike but Coffing parts are made of
specific materials or processed to achieve specific
properties.
Concept & Features
Overload Protection Devices, also known as Load
Limiters, are safety devices designed to limit overload
conditions.
The LHH hand chain hoist has an optional load limiter.
The load limiter is a device that is designed and
calibrated to prevent excessive overloads. Excessive
overload is indicated by hand-chain movement without
corresponding movement of the lower hook block or
load when the unit is operate
d in the “up” direction.
Should an overload condition be evident, immediately
operate in the “down” direction to remove the excess
load from the unit.
The reduction of the load to the rated capacity or less
will result in automatic restoration to the normal
operation of the unit.
The LHH Load Limiter device can be retrofitted to
existing LHH-B manual chain hoists which were
shipped without the Load Limiter option factory-
installed. The Load Limiter can be installed simply by
replacing the Standard components with the Load
Limiter components.
Structure
The LHH Load Limiter is a friction clutch type load
limiter device. Fig.-1 illustrates its structure. The hand
wheel and friction disc are located between the disc
hub. They are clamped by the force of a disc spring
compressed by a locknut to make a friction-clutch
mechanism. The mechanism is set to a pre-set slip
torque as desired.
The Load Limiter disables
operating in the “up”
direction during a possible overload condition, which
operator may not be aware of. During an overload
condition, the device works by declutching the unit
which allows the hand-chain to be pulled without lifting
the load. Therefore, the chain hoist will not be
excessively overloaded, which will minimize damages
to the hoist. The Load Limiter will allow operation in
the “down” direction during an overload condition.
Remove the overload from the hoist as soon as
possible.
Setting the Load Limiter
Load Limiters are set to slip within a given range. Load
Limiters are being set at 125-175% of the rated load
from the factory.
