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8-3. "Three-Mode" Changeover Mechanism
The change lever of the Model DH 24DVA permits quick and easy changeover among the "rotation and
hammering", "rotation only" and "hammering only" functions. Each function mode is explained below.
(1) Rotation and hammering (Fig. 8)
Adjust the change lever to "rotation and hammering" ( marks). Armature rotation is transmitted to the first
gear and second shaft, and then to the clutch via the spline of the second shaft. Claws on the end surface of
the clutch engage with matching claws of the reciprocating bearing ( A portion in the figure) to convert the
rotation into reciprocating motion. Three claws on the tip of the second shaft engage with matching three
claws of the pinion sleeve all the time, and the second shaft rotation is transmitted to the pinion sleeve. Then
claws on the large-dia. portion of pinion sleeve engage with the second pinion ( B portion in the figure), and
the rotation is transmitted to the second gear and the cylinder.
Three claws of second shaft
Spline of the
second shaft
Second shaft
Change lever
Fig. 8
First gear
Pinion sleeve
Reciprocating bearing
B
portion is engaged
(rotation transmitted).
Clutch
A portion is engaged
(hammering transmitted).
Second pinion
