7
GB
8. SAFETY DEVICES
8.1. Overload limiting safety devices
All tirfor
®
machines incorporate a shear pin system. In
case of overload, one or more pins (depending on the
model), fitted to the forward operating lever, shear and
prevent further forward or lifting operations. Reverse
operation is still possible to enable the load to be
lowered or the wire rope to be slackened.
8.2. Rope release safety device
Models TU
™
and T500D are fitted with a “two-handed”
rope release system which requires deliberate operation
by the user to release the machine. See section
4: “Releasing and engaging the jaws”.
9. REPLACEMENT OF SHEAR PINS
Figures 17, 18, 19 and 20 show the position of the shear
pins for the various models. Spare shear pins are in the
operating levers for models TU
™
8 and TU
™
16, and in
the rope release lever for the other models (first remove
the plastic cap).
Remove the sheared pins with a suitable punch. For
models TU
™
8 and TU
™
16, remove the forward operating
handle stub by using an extractor.
Clean the recesses which house the pins. For models
TU
™
and TU
™
16, refit the forward operating handle stub
on the crank, lining up the grooves in the crank with
those in the operating handle (Figs 17 and 18).
For models T500D and TU
™
32, align the holes of the
upper and lower sections of the forward operating lever.
Position the spare shear pin(s) and drive it/them in with
a hammer.
WARNING: It is forbidden to replace sheared
pins by anything other than genuine tirfor
®
shear
pins of the same model.
Before putting the machine back into operation, ensure
that the cause of the overload is removed. If necessary,
use multiple sheave blocks (Fig. 6). Remember to re-
order sheared pins and put them back in the correct place.
10. WIRE ROPE
To guarantee the safe operation of tirfor
®
machines,
it is essential to use them exclusively with tirfor
®
wire
rope which has been specially designed to meet the
requirements of the tirfor
®
machine.
tirfor
®
wire ropes
have a red strand which is visible on new rope.
One end of the wire rope has an end fitting, such as a
safety hook, fitted to a thimble fixed by a metal ferrule
(Fig. 21). The other end of the wire rope is fused and
tapered (Fig. 22).
A wire rope in good condition is a guarantee of
safety, to the same extent as a machine in good
condition.
It is necessary to continuously monitor the
state of the wire rope, to clean and oil it with a rag
soaked with motor oil or grease.
Grease or oil containing graphite additives or
molybdenum disulphide must not be used.
Visual examination of the wire rope
The wire rope should be examined daily to detect any
signs of wear (damage or broken wires: see examples
in Fig. 23).
In case of any apparent wear, have the wire rope
checked by a competent person. Any wire rope with a
reduction from the nominal diameter by more than 10%
should be replaced (see Fig. 24 for the correct method
of measuring the diameter of a wire rope).
IMPORTANT:
It is recommended, specially for
lifting applications, to ensure that the length of wire rope
is greater than actually required. Allow an extra meter
approximately.
When lifting or lowering loads over long lengths of
wire rope, steps should be taken to stop the load from
rotating to prevent the wire rope from unlaying.
Never allow a tensioned wire rope to rub over sharp
edges. The wire rope must only be used with pulleys of
an appropriate diameter.
Never expose the wire rope to temperatures beyond
100°C. Never use wire rope that has been subject
to damage such as fire, corrosive chemicals or
atmosphere, or exposed to electric current.
Storage: see section 7: “Decommissioning and storage”.
11. MAINTENANCE INSTRUCTIONS
The machine should be inspected, cleaned and
lubricated at regular intervals, at least annually, by an
approved TRACTEL
®
repairer.
Never use grease or oil containing graphite additives or
molybdenum disulphide.
To clean the machine, soak in a bath of approved
cleaning fluid but not acetone or derivatives or ethylene
trichloride or derivatives. Then shake the machine
vigorously to loosen foreign matter and turn it upside
down to allow the dirt to come out through the openings
for the operating levers. Allow the mechanism to drain
and become dry.
After this treatment,
ensure that the machine is
well lubricated
by applying a quantity of oil (type
SAE 90-120) onto the internal mechanism through the
openings for the operating levers, and for the models
TU
™
8 and TU
™
16, through the special lubrication
holes. To carry out this procedure, it is best for the jaw
mechanism to be in the released position.
Alternatively operate the forward and reverse operating
levers to allow the lubricant to penetrate all parts of
the mechanism.
