6
Installing or removing the bit
CAUTION:
Always be sure that the tool is switched off and
unplugged before installing or removing the bit.
Clean the bit shank and apply bit grease before installing
the bit. (Fig.2)
Insert the bit into the tool. Turn the bit and push it in until
it engages. (Fig.3)
After installing, always make sure that the bit is securely
held in place by trying to pull it out.
To remove the bit, pull the chuck cover down all the way
and pull the bit out. (Fig.4)
Depth gauge (Fig.5)
The depth gauge is convenient for drilling holes of uni-
form depth. Loosen the side grip and insert the depth
guage into the hole in the side grip. Adjust the depth
gauge to the desired depth and tighten the side grip.
NOTE:
The depth gauge cannot be used at the position where
the depth gauge strikes against the gear housing.
Switch action (Fig.6)
CAUTION:
Before plugging in the tool, always check to see that the
switch trigger actuates properly and returns to the “OFF”
position when released.
For Model HR2020, HR2020X and HR2021
To start the tool, simply pull the switch trigger. Tool speed
is increased by increasing pressure on the switch trigger.
Release the switch trigger to stop. For continuous opera-
tion, pull the switch trigger and then push in the lock but-
ton. To stop the tool from the locked position, pull the
switch trigger fully, then release it.
For Model HR2022
To start the tool, simply pull the switch trigger. Release
the switch trigger to stop. For continuous operation, pull
the switch trigger and then push in the lock button. To
stop the tool from the locked position, pull the switch trig-
ger fully, then release it.
Reversing switch action (Fig. 7)
For Model HR2020 and HR2020X
This tool has a reversing switch to change the direction of
rotation. Move the reversing switch lever to the A side for
clockwise rotation or the B side for counterclockwise
rotation.
CAUTION:
• Always check the direction of rotation before operation.
• Use the reversing switch only after the tool comes to a
complete stop. Changing the direction of rotation
before the tool stops may damage the tool.
• When you operate the tool in counterclockwise rotation,
the switch trigger is pulled only halfway and the tool
runs at half speed. For counterclockwise rotation, you
cannot push in the lock button.
Selection action mode (Fig.8)
This tool employs an action mode changing knob. Select
one of the two modes suitable for your work needs by
using this knob. For rotation only, turn the knob so that
the arrow on the knob points toward the Msymbol on
the tool body. For rotation with hammering, turn the knob
so that the arrow on the knob points toward the r sym-
bol on the tool body.
CAUTION:
• Always set the knob fully to your desired mode symbol.
If you operate the tool with the knob positioned half-
way between the mode symbols, the tool may be dam-
aged.
• Use the knob after the tool comes t o a complete stop.
Torque limiter
The torque limiter will actuate when a certain torque level
is reached. The motor will disengage from the output
shaft. When this happens, the bit will stop turning.
CAUTION:
• As soon as the torque limiter actuates, switch off the
tool immediately. This will help prevent premature wear
of the tool.
• Hole saws cannot be used with this tool. They tend to
pinch or catch easily in the hole. This will cause the
torque limiter to actuate too frequently.
Hammer drilling operation
Position the bit at the desired location for the hole, then
pull the trigger.
Do not force the tool. Light pressure gives best results.
Keep the tool in position and prevent it from slipping away
from the hole.
Do not apply more pressure when the hole becomes
clogged with chips or particles. Instead, run the tool at an
idle, then remove the bit partially from the hole. By
repeating this several times, the hole will be cleaned out
and normal drilling may be resumed.
CAUTION:
There is tremendous and sudden twisting force exerted
on the tool/bit at the time of hole breakthrough, when the
hole becomes clogged with chips and particles, or when
striking reinforcing rods embedded in the concrete.
Always use the side grip (auxiliary handle) and firmly
hold the tool by both side grip and switch handle during
operations. Failure to do so may result in the loss of con-
trol of the tool and potentially severe injury.
Bit grease
Coat the bit shank head beforehand with a small amount
of bit grease (about 0.5 – 1 g).
This chuck lubrication assures smooth action and longer
service life.
Blow-out bulb (Fig.9)
Use the blow-out bulb to clean out the hold.
Dust cup (Fig.10)
Use the dust cup to prevent dust from falling over the tool
and on yourself when performing overhead drilling opera-
tions. Attach the dust cup to the bit as shown in Fig. 10.
The size of bits which the dust cup can be attached to is
as follows.
Bit diameter (mm)
Dust cup 5 6–14.5
Dust cup 9 12– 16