Hitachi DH 28PC Technical Data And Service Manual page 5

Highest demolition performance in its class
Hitachi achieved the highest demolition performance in this class of product by optimizing the hammering
properties.
• Comparison of chiseling amounts (Test results obtained at Hitachi factory)
HITACHI
DH 28PC
C
* The chiseling amount is dependent upon test conditions.
* "C" has no "Hammering" mode.
Equipped with a reversing switch
This product is equipped with a reversing pushbutton switch.
The user can select either forward rotation (clockwise) or backward rotation (counterclockwise) by simply
pressing the pushbutton.
Refer to the Technical Data and Service Manual for the model indicated below.
DH 24PC2 / No. E479, DH 24PC3 / No. E489, DH 30PC2 / No. E494
3-mode changing and variable lock mechanism for easy
working-angle adjustment of chisels, etc.
This product adopts Hitachi's unique mode selection mechanism: two standard modes of "Rotation +
hammering" and "Rotation" and one additional mode of "Hammering." These modes enables not only light
chiseling work using bull points but also heavy work using cold chisels and cutters such as groove digging
and cornering work, thereby expanding the range of product use.
The user can easily mount a bit in any of 12 angle positions by simply setting the change lever to the
"neutral" position and turning the bit.
Idle striking prevention mechanism with catch-ring method
This product adopts a catch-ring type of idle hammering prevention mechanism.
When the bit tool of the product is detached from an object under no load, air flows in and out through
cylinder air holes to maintain uniform air pressure in the chamber. As a result, the hammering action stops.
In this case, the projection at the tip of the striker fits into the O-ring (A) provided between damper holders
(A) and (B) to prevent the air holes from being blocked by the recoiling striker.
0 5 10
Chiseling amount (kg/30 min.)
18.2
15 20
-2-
*Based on our own
research
25.2
25 30