Huskie Tools HH1500, Service Manual

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2. OPERATING INSTRUCTIONS
HOW THE HAMMER OPERATES
On larger hammers the main valve is contained in the valve box, which is bolted to the
cylinder (Figure 1). During the upward stroke, the pressure in the upper chamber is
released via the main valve and through the outlet. High pressure in the lower chamber
then forces the piston upward.
As soon as the piston reaches the upper end of the stroke, the main valve directs flow to
the upper chamber causing it to become high pressure.
Since surface
A is greater than surface B , the piston is driven downward with the help of
the accumulated energy from the gas chamber, creating the impact stroke of the hammer.
At the point of impact, the main valve shifts, releasing the high pressure from the upper
chamber, enabling the upward stroke to occur again.
Figure 1. Principle of Operation
(Refer to Table 10.)
Gas
Chamber
Pressure
receiving
surface A
Piston
Pressure
receiving
surface B
Lower Chamber
High pressure
Middle Chamber
Low pressure
Main Valve
Valve Box