joke 4910880, User Manual

Page: 12 / 68

12
SAFETY SYSTEMS
SAFETY
These systems are listed below, together with a description of how they work:
1. Resonator shutter
2. Microscope shutter
3. Microscope infrared filter
4. Infrared welding filter
Description This device consists of a panel operated by an electro-magnet and
located inside the LASER resonator.The shutter interrupts the path of
the LASER inside the resonator when the welding machine is in
STAND-BY.
Purpose The purpose of the resonator shutter is to prevent the generation of
unwanted LASER radiation.
Operation
When the electrical power supply is switched on, but before rotating the
key switch to the START position, the shutter is activated. When the
operator rotates the key switch to the START position, the shutter opens
the LASER path, so that the welding machine is ready for normal
operation. When the key is set to the LOCK position, the machine
executes the switch off procedure, the shutter is closed and a check is
performed to ensure that it is closed within the specified time interval.
Description This device consists of an LCD (liquid crystal display) filter that, when a
specific voltage is applied to it, becomes completely opaque. It is
positioned between the 45° mirror and the microscope focusing lens.
The shutter intervenes by interrupting the operator’s view through the
microscope at the moment the LASER causes the workpiece to melt.
Purpose
The purpose of this device is to:
•
Prevent the operator from being dazzled by the flash of visible
radiation light emitted by the weld pool.
As explained later in this manual, the microscope shutter constitutes the
second of three safety devices designed to prevent LASER radiation
from reaching the operator’s eyes indirectly.
Operation The SHUTTER OPEN position corresponds to the normal operating state
of this device both when the machine is in STAND-BY (resonator shutter
ON), and when it is in START (resonator shutter OFF). This means that
the microscope may be used at any time. After the operator has rotated
the key switch to the START position, the shutter operating logic is as
follows:
•
The operator presses the firing pedal;
•
The microprocessor detects that the pedal contact has closed
and commands the shutter to close;
•
The microprocessor activates the LASER lamp;
•
The shutter remains in the ON position for a period corresponding
to the LASER ignition time, plus an additional interval sufficient to
allow the weld pool to cool down and, hence, lose its luminosity.
•
The shutter returns to its home position and the system checks
that it is fully open.
1. RESONATOR SHUTTER
2. MICROSCOPE SHUTTER
3. MICROSCOPE INFRARED FILTER
4. INFRARED WELDING FILTER