Method Of Operation; Switching On/Off; Practical Advice - Bosch GDR 14,4 V-LI MF Professional Notice Originale

sleeve (2) to lock the application tool.
Use only screwdriver bits with ball catch (12) (DIN 3126-
E6.3). Other screwdriver bits (14) can be inserted using a
universal bit holder with ball catch (13).
Removing
Pull the locking sleeve (2) forward and remove the applica-
tion tool.
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 work-
ing 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 thus load is put on the motor. In
this instance, the impact mechanism converts the power of
the motor to steady rotary impacts. When loosening screws
or nuts, the process is reversed.
Start-up
Inserting the Battery
Use only original Bosch lithium-ion batteries with the
u
voltage stated on the type plate of your power tool.
Using other batteries can lead to injuries and pose a fire
hazard.
Push the charged battery (7) into the base of the power tool
from the front until the battery is securely locked.
Set the rotational direction (see figure B)
The rotational direction switch (9) is used to change the ro-
tational direction of the power tool. However, this is not pos-
sible while the on/off switch (10) is being pressed.
Right rotation: To drive in screws and tighten nuts, press
the rotational direction switch (9) through to the left stop.
Left Rotation: To loosen and unscrew screws and nuts,
press the rotational direction switch (9) through to the right
stop.
Setting the operating mode (see figure C)
Note: Only change the operating mode when the power tool
is switched off. Otherwise, the power tool may become dam-
aged.
To change the operating mode, push the "Drilling/screwdriv-
ing" selector switch (4) to the required position.
If the "Drilling/screwdriving" selector switch (4) cannot be
pushed as far as the stop, gently press the on/off switch
(10) and release it again before pushing the "Drilling/screw-
driving" selector switch (4) to the required position.
Always push the "Drilling/screwdriving" selector switch (4)
as far as it will go. Operating the power tool with the
"Drilling/screwdriving" selector switch (4) not fully in posi-
tion can damage the power tool.
Position for impact drilling
Bosch Power Tools
Position for slow drilling with a large drilling
diameter in wood, metal, ceramic and plastic
Position for rapid drilling with a small drilling
diameter in wood, metal, ceramic and plastic

Switching on/off

To start the power tool, press and hold the on/off switch
(10).
The lamp (3) lights up when the on/off switch (10) 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 (10).
Adjusting the Speed
You can adjust the speed of the power tool when it is on by
pressing in the on/off switch (10) to varying extents.
A light pressure on the on/off switch (10) results in a low ro-
tational speed. Increased pressure on the switch causes an
increase in speed.

Practical advice

Only apply the power tool to the screw/nut when the
u
tool is switched off. Rotating tool inserts can slip off.
When drilling, do not apply too much pressure to the
u
power tool. Excessive pressure can damage the tip of the
drill bit, compromise the performance and shorten the
service life of the power tool.
Working in especially dusty environments can lead to
u
failure of the power tool. If the power tool suddenly
fails, remove the carbon brushes and check them (see
section "Replacing the carbon brushes").
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.
A torque gradient depends on the following factors:
– Strength properties of the screws/nuts
– Type of backing (washer, disc spring, seal)
– Strength properties of the material being screwed/bolted
together
– Lubrication conditions at the screw/bolt connection
The following application cases result accordingly:
– A hard seat is a metal-to-metal screw application which
uses washers. After a relatively short impact duration, the
maximum torque is achieved (steep characteristic curve).
English | 15
1 609 92A 4AK | (15.05.2018)