the special chuck key, tightening equally in all
three bores.
for keyless-chucks
Grip rear collar of chuck III and rotate front collar
until chuck III is opened sufficiently for the tool to
be inserted, then tighten front collar. An audible
"click" indicates that the chuck has automatically
locked.
REMOVING THE CHUCK
for three-jaw chuck rotary hammers:
Open the jaws of chuck III completely, and by
means of a screwdriver unwind the left-threaded
securing screw. Fix the adapter 3 by an open-
end spanner (17 mm). Insert the special key
for chuck tightening in one of the three bores
and rotate the chuck anti-clockwise, using the
chuck key as a lever, to unscrew chuck III from
the adapter.
for keyless-chuck rotary hammers:
Grip rear collar of keyless chuck and rotate
front collar until chuck is opened. By means of
a screwdriver unwind the left-threaded securing
screw. Insert Allen key or screwdriver bit into the
chuck and clamp its free end in appropriate way.
Clutch the rotary hammer spindle and rotate it in
anti-clockwise direction by an open-end span-
ner.
INSERTING AND fASTENING CHISELS
Set mode selector switch 6 to hammer drilling
mode. Pull backward the cup of socket 2. Insert
the chisel until stop. Set mode selector switch
6 to symbol "point" for adjusting the chisel; in
order to rotate the chisel in optimum operating
position. Turn and fix mode selector switch 6 to
position "hammer". For chiselling, mode selec-
tor switch 6 must always point toward symbol
"hammer".
SCREWING / UNSCREWING BOLTS,
SCREWS AND NUTS
Following
the
above-described
tighten the corresponding accessory into chuck
III. Set mode selector switch to symbol "drill
bit". Select the rotation necessary by lever 10.
These operations must be performed only at low
speed.
WARNING: In case of driving long
bolts and screws there is a danger of slipping
the rotary hammer.
8
EN
AUxILIARY HANDLE
Tighten the auxiliary handle 9 on the journal 4 of
the rotary hammer. In the interests of safety, the
auxiliary handle 9 should always be used. The
depth gauge 8 can be used for fixing the depth
of the drilled bores.
The auxiliary handle for these models is con-
nected to the body of the machine through vi-
bration dampers, protecting the operator and
reducing fatigue.
TORqUE LIMITATION
The safety clutch limits the torque. Upon actuat-
ing the safety clutch stops the spindle rotation
and the tool ceases to rotate. In this case switch
the machine off immediately to avoid premature
wear.
RECOMMENDATIONS fOR OPERA-
TION
At low ambient temperatures and after storage
let the machine run at no load in order to warm
up, thus improving lubrication. Hammer drilling
is impossible without properly warmed-up ma-
chine.
Apply moderate pressure during drilling in con-
crete (approximately 80-100 N). Higher pressure
will not increase drilling efficiency, but it will lead
to decreasing the operation life of the machine.
Clean and lubricate the tool shank prior to in-
serting it. Take the drill out of the opening from
time to time to remove dust. Watch out the stage
of blunting of the bit and change it if consider-
able decrease of efficiency is observed.
Do not operate the machine in "hammer drilling"
and "hammer" mode with the lever 10 in leftmost
position.
Depending on the processed material it is pos-
sible that the impact energy may decrease dur-
ing operation in "hammer" mode (chiselling and
demolishing and in "hammer drilling" mode. To
restore the maximum impact energy it is neces-
sary to reduce the revolutions by decreasing the
procedure,
pressure on switch trigger 12 until the advent of
stable impact.
Before drilling large-diameter holes in metal,
first drill a small pilot hole.
The optimum capacity when drilling in concrete
is up to 16 mm, and the possible capacity is up
to 24 mm.
The rotary hammer is suitable for light-duty chis-
elling. Higher durability and efficiency can be
achieved only when using sharp chisels.
BP 241E ● BPR 241E