Safety Devices; Replacing The Shear Pins - Tractel tirfor TU Série Manuel D'installation Et D'entretien

• The wire ropes must be totally removed from
GB
the devices and stored on reelers.
Before winding them on the reelers, it is
advisable to inspect them, clean them with a
brush and grease them.
Incorrect

8. SAFETY DEVICES:

8.1. tirfor ® hoists:
8.1.1. Overload safety devices:
All models have a system of shear pins. In the
event of excessive overload, one or more pins
(depending on the model) on the forward lever
shear, making it impossible for movement to
continue. However it still remains possible to
carry out lowering operations using the reverse
lever.
8.1.2. Releasing safety device:
Models TU6P, TU12P and TU24P have a "two
handed" release system which makes it
necessary to perform a deliberate operation to
release the device (see section "Releasing and
closing the jaws").
Correct
8.2. blocstop™ safety devices:
Faults are detected by the lever equipped with
the detection roller
suspension rope. When the lever drops
downwards, the blocstop™ grips onto the
secondary rope and prevents the platform from
falling. There are four possible causes of faults
or incidents which lead to the blocstop™
gripping:
• Breaking of the suspension rope
• Failure of the hoist
• The platform meeting an obstacle
while being lowered, creating slack on
the suspension rope.
• Tilting of the platform by more than
14 ° from horizontal.
For the first two faults (breaking of the
suspension rope and and hoist failure), a
rescue operation
evacuate the people on the platform.
For the third incident (meeting an obstacle),
the operator must mechanically re-tension the
suspension rope concerned by moving the hoist
upwards and freeing the platform from the obs-
tacle. The blocstop™ releases its hold on the
secondary rope automatically.
For the last incident (tilting), the operator must
return the platform to horizontal by operating the
hoist on the lower side, to move it upwards. The
blocstop™ releases
secondary rope automatically.

9. REPLACING THE SHEAR PINS:

Diagrams below show the location of the shear
pins on the TU
TM
TU 24PM hoists. The replacement pins are in
the forward lever for the TU
TM
TU 12PM and in the release lever for the
TM
TU 24PM (the plastic plug must be removed).
TM
On models TU
forward lever must first be removed from its
shaft. This requires the use of a hub extractor.
Remove the sheared pins using a pin extractor.
12
which runs on
must be organised
its hold on
TM TM
6PM, TU 12PM
TM
6PM and
TM
6PM and TU 12PM the
the
to
the
and