Chuck Section; Dust Collector (B) - Hitachi DH 24PF3 Technical Data And Service Manual

8-5. Chuck Section

The tool retainer is structured as shown in Fig. 12.
The tip of the tool retainer is covered with the front cap (made of rubber) to prevent dust and chips from getting
inside. The steel ball falls into the round groove of the bit to prevent the tool from coming off and the two key rails
transmit the rotation torque.
To mount the bit, push the bit in the tool retainer as far as it will go. Pushing lightly, turn the bit until it is caught.
At this position, push the bit in as far as it will go (sliding the grip is not required for mounting the bit). To remove
the bit, slide the grip backward to the full and remove the bit.

8-6. Dust Collector (B)

When drilling holes overhead, dust collector (B) can be mounted on the Model DH 24PF3 to prevent dust and
chips from falling downward. Dust collector (B) is intended solely for use when drilling holes in concrete, and
cannot be used for drilling holes in steel or wood. It is designed for use with drill bits with overall length of 110
mm, 160 mm and 166 mm, and cannot be used with any longer bits. When using a drill bit with an overall length
of 166 mm with dust collector (B), drilling up to a depth of approximately 72 mm is possible. When using dust
collector (B), ensure it is securely fastened to the grip on the main body with socket adapter (B). Although the
socket and socket adapter (B) rotate together with the tool shank, there is a steel ball between the outer race and
the socket which serves as a ball bearing. Should the dust cover be forced against the concrete surface, it will not
rotate even though the tool shank continues to rotate. Should the tool be operated when the dust cover is not
being held against a concrete surface, inertia may cause dust collector (B) to become disconnected from the grip.
Accordingly, caution the customer to press dust collector (B) and drill bit firmly against the concrete surface before
turning on the switch to start drilling. When dust collector (B) is used, almost no dust and chips are scattered
about. However, since the chips and dust remaining in the collector may scatter after completion of the drilling
operation, the customer should be advised to always wear protective glasses. When dust collector (B) is
disassembled for repair or maintenance, be very careful to prevent oil or grease from adhering to the steel balls.
Grease or oil on the steel balls may cause concrete dust to enter the unit and cause defective rotation.
Grip
Holder spring
Washer (B)
Cylinder
Holder plate
Fig. 12
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Ball holder
Steel ball
Front cap
Stopper ring
Key rail (2 pcs.)