Hitachi DH 40MRY Technical Data And Service Manual page 20

Switching between "Rotation + hammering", "Neutral" and "Hammering only"
Lock sleeve
Cylinder
Change lever
Fig. 11
Lock sleeve
Cylinder
Change lever
Fig. 12
Lock sleeve
Cylinder
Change lever
Fig. 14
Clutch
Bevel gear
Clutch
Bevel gear
Clutch
Bevel gear
All the shanks of the SDS-max type working tools such as
drill bits (for drilling) and bull points (for chiseling) have the
same shape. When chiseling or chipping with the Model
DH 40MRY, it is necessary to stop the rotation and choose
the "Hammering only" mode by means of the change lever
to lock the working tool against rotation.
Figure 11 is a cross-sectional view showing the "Rotation +
hammering" mode, in which the bevel gear claw meshes
with the clutch claw to transmit rotation to the cylinder
keyed to the clutch, so as to rotate the working tool.
Figure 12 is a cross-sectional view showing the "Neutral"
mode, in which, with the change lever turned 90û, the bevel
gear is brought out of engagement with the clutch to cut off
transmission of rotation. In this position, the tool holder grip
can be manually turned and the working tool (for chiseling
or chipping) is adjustable to the desired position in 12 steps
easily (Fig. 13).
Figure 14 is likewise a cross-sectional view showing the
"Hammering only" mode. With the change lever turned
another 90û, the splines on the inner circumference of the
lock sleeve come into mesh with the splines on the outer
circumference of the clutch, so that the cylinder is
prevented from rotating as well as the working tool.
Although the Model DH 40MRY has three selectable
modes as mentioned above, use of a working tool for
chipping or chiseling in the "Rotation + hammering" mode
will result in an accident. Be sure to instruct the customers
to select the "Hammering only" mode when doing chiseling
or chipping work.
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Grip
Fig. 13