Hitachi NT 65M2, Technical Data And Service Manual

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(4) Single actuation mechanism/contact actuation mechanism: (Fig. 8 and Fig. 9)

Single/contact actuation mechanism changeover is accomplished by turning the switching device

(Change Knob (C) 

[58]

).

Single actuation mechanism (Switching device:

upward position):

1) Immediately after driving the first nail, the

control valve should be as shown in Fig. 7.

2) When only Pushing Lever (B) 

[40]

 is released

and Trigger (C) Ass'y 

[36]

 is held as shown in

Fig. 8, the plate of Trigger (C) Ass'y 

[36]

contacts Change Knob (C) 

[58]

 and the Plunger

[67]

 returns (lowers) only halfway.

Because of this, compressed air does not flow

into the valve piston lower chamber, and Valve

Piston 

[63]

 remains in the lowered position.

Accordingly, the Piston 

[12]

 remains in the

lowered position as shown in Fig. 6.

3) When Trigger (C) Ass'y 

[36] 

is released, the

Plunger

 [67]

 returns (lowers) completely as

shown in Fig. 5.  Compressed air then flows into

the valve piston lower chamber, and the Valve

Piston 

[63]

 is forced upward.  The Piston 

[12]

then returns fully upward.  Therefore, unless

Trigger (C) Ass'y 

[36]

 is released after each

nailing operation, the structural mechanism

prevents the next nailing operation.

Contact actuation mechanism (Switching device:

downward position):

1) Immediately after the first nail is driven, the

control valve should be as shown in Fig. 7.

2) Even when only Pushing Lever (B) 

[40]

 is

released and Trigger (C) Ass'y 

[36]

 is held, the

Plunger 

[67]

 returns (lowers) completely as

shown in Fig. 9.  Thus the Piston 

[12]

 returns

(raises) fully.  Accordingly, continuous nailing

can be accomplished by pushing only Pushing

Lever (B) 

[40]

 up and down while holding

Trigger (C) Ass'y 

[36]

 depressed.

Plunger 

[67]

Valve piston
lower chamber

Trigger (C)
Ass'y 

[36]

Valve Piston 

[63]

Accumulator

Switching device (Change Knob (C) 

[58]

)

(Upward position)

Fig. 8  Single actuation mechanism

Plunger 

[67]

Pushing Lever (B) 

[40]

Valve portion
lower chamber

Trigger (C) Ass'y 

[36]

Valve Piston 

[63]

Accumulator

Switching device (Change Knob (C) 

[58]

)

(Downward position)

Fig. 9  Contact actuation mechanism