In the third working chamber, there is formed an oscillating column of the working medium, which presses against {HEAD ~ the inner sides} of {TAIL ~ both pistons} 
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In the third working chamber , there is formed an oscillating column of the working medium , which presses against { HEAD ~ the inner sides } of { TAIL ~ both pistons }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL