Bosch GDR 120-LI Professional Notice Originale page 8

8 | English
Changing the Tool
Remove the battery from the power tool before carry-
u
ing out work on the power tool (e.g. maintenance,
changing tool, etc.). The battery should also be re-
moved for transport and storage. There is risk of injury
from unintentionally pressing the on/off switch.
GDR 120-LI:
Inserting the application tool (see figure B)
Pull the locking sleeve (2) forward, guide the application tool
into the tool holder (1) up to the stop and release the locking
sleeve (2) to lock the application tool.
Screwdriver bits (13) can be inserted using a universal bit
holder with ball catch (12).
Removing
Pull the locking sleeve (2) forward and remove the applica-
tion tool.
GDS 120-LI: (see figure C)
When working with an application tool, pay attention
u
that the application tool is connected securely to the
tool holder. When the application tool is not securely
connected with the tool holder, it can come off during ap-
plication.
Slide the application tool (14) onto the square drive of the
tool holder (1).
Due to the way the system operates, the application tool
(14) will move around slightly in the tool holder(1); this has
no influence on the function/safety.
Operation
Method of Operation
The tool holder (1) (with the application tool) is driven by an
electric motor via a gear and impact mechanism.
The working procedure is divided into two phases:
Screwing in and tightening (impact mechanism in action).
The impact mechanism is activated as soon as the screwed
connection runs tight and load is therefore put on the motor.
The impact mechanism then converts the power of the mo-
tor to steady rotary impacts. When loosening screws or nuts,
the process is reversed.
Starting Operation
Inserting the Battery
Set the rotational direction switch (7) to the middle position
to avoid unintentionally switching it on. Insert the charged
battery (6) into the handle until you feel it engage and it is
flush with the handle.
Set the rotational direction (see figure D)
The rotational direction switch (7) is used to change the ro-
tational direction of the power tool. However, this is not pos-
sible while the on/off switch (8) is being pressed.
Right rotation: To drive in screws and tighten nuts, press
the rotational direction switch (7) through to the left stop.
1 609 92A 70Y | (22.03.2023)
Left Rotation: To loosen and unscrew screws and nuts,
press the rotational direction switch (7) through to the right
stop.
Mechanical gear selection
Only operate the gear selector (3) when the power
u
tool is not in use.
You can preselect two speed ranges with the gear selector
(3).
Gear I:
Low speed range; for screwdriving or working with a large
drilling diameter.
Gear II:
High speed range; for working with a small drilling diameter.
If the gear selector (3) cannot be swivelled all the way to the
stop, turn the drive spindle slightly with the drill.
Switching on/off
To start the power tool, press and hold the on/off switch
(8).
The lamp (9) lights up when the on/off switch (8) is lightly or
fully pressed, meaning that the work area is illuminated in
poor lighting conditions.
To switch off the power tool, release the on/off switch (8).
Adjusting the speed
You can adjust the speed of the power tool when it is on by
pressing in the on/off switch (8) to varying extents.
A light pressure on the on/off switch (8) results in a low rota-
tional speed. Increased pressure on the switch causes an in-
crease in speed.
Temperature-dependent overload protection
In normal conditions of use, the power tool cannot be over-
loaded. If the power tool is overloaded or the permitted bat-
tery temperature is exceeded, the electronics of the power
tool will switch off until the temperature returns to within the
optimum operating temperature range.
Practical advice
Only apply the power tool to the screw/nut when the
u
tool is switched off. Rotating tool inserts can slip off.
The torque depends on the impact duration. The maximum
achieved torque results from the sum of all individual
torques achieved through impact. Maximum torque is
achieved after an impact duration of 6–10 seconds. After
this duration, the tightening torque is increased only minim-
ally.
The impact duration is to be determined for each required
tightening torque. The tightening torque actually achieved
should always be checked with a torque wrench.
Screw applications with hard, spring-loaded or soft seats
When the achieved torques in an impact series are measured
during a test and transferred into a diagram, the result is the
curve of a torque characteristic. The height of the curve cor-
responds to the maximum achievable torque, and the steep-
ness indicates the duration in which this is achieved.
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