Hitachi DH 28PC Technical Data And Service Manual page 6

One-push type of bit mounting
This product adopts a one-push quick bit mounting system without needing grip operation.
First, fully insert the bit tool into the front cap hole until it stops, and then turn the bit tool while slightly
pushing the bit tool. When the bit tool catches, push the bit tool there until it stops.
Internal pressure adjustment mechanism
An air passage is provided to connect inside the crankcase to the outside with a felt packing in the air
passage. This passage only allows air (pressure) to pass and suppresses fluctuations in internal pressure.
This stabilizes the hammering action and prevents idle striking and the leakage of grease.
Easy-to-operate and double-molded switch handle and
side handle
The switch handle and side handle both feature a two-layer structure in which the plastic resin molded
base is fully coated with a soft plastic resin. This gives the switch and side handles a soft feeling, and
improves handle operability.
Front cap
Tool
Crank cover
Felt packing
Air passage
(Inside the crankcase)
-3-
Grip
Air
Felt packing (B)
Rubber seal