Hitachi DH 24DVA Technical Data And Service Manual page 27

(2) Rotation only (Fig. 9)
Adjust the change lever to "rotation only" (
lever, and the clutch is moved forward at the back end of the lock plate. Engagement between the clutch and
the claws of the reciprocating bearing is released ( A portion in the figure). Thus no rotation is transmitted to
the reciprocating bearing and hammering is stopped. On the other hand, the pinion sleeve engages with the
second pinion ( B portion in the figure), and so the rotation is transmitted to the pinion sleeve for "rotation
only" function.
A portion is separated (hammering stopped).
Claw of reciprocating bearing
Reciprocating bearing
(3) Hammering only (Fig. 10)
Adjust the change lever to "hammering only" (
pin of the change lever. Engagement between the pinion sleeve and the second pinion is released and no
rotation is transmitted ( B portion in the figure). The lock plate is moved to the motor side by spring (C) and
engaged with the locking claw of the second pinion to lock the cylinder rotation ( C portion in the figure).
On the other hand, the clutch engages with the reciprocating bearing for "hammering only" function ( A portion
in the figure).
C portion is engaged (tool locked).
Reciprocating bearing
A portion is engaged (rotation transmitted).
mark). The lock plate is moved forward by the pin of the change
Claw of
clutch
Lock plate (rear end portion)
Lock plate (front end portion)
Locking claw of second pinion
Second
pinion
Fig. 9
mark). The second pinion is moved to the motor side by the
Clutch
Fig. 10
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Change lever
Change lever pin
Pinion sleeve
B portion is engaged
(rotation transmitted).
Change lever
Change lever pin
Second pinion
Pinion sleeve
B portion is separated
(rotation stopped).
Lock plate (front end portion)