are articulated via a swivel 30 the end of the rod 31 of jack 35 and a connecting rod 32 the other end of which is articulated via a swivel 33 to the end of the pendular arm 21 of piston 22 at the end of arm 29b is articulated a connecting rod 34 the other end of which is articulated at the free end of the pendular arm 27 of the equilibration mass the frame assembly 11 corresponds to the second compression stage and it carries likewise a number of axles which are perpendicular to its orientation direction viz in its upper plane the articulation axle 40 of the suspension arm 41 of the pendular piston 42 providing the compression of the second stage the axle 43 from which is suspended via a swivel 44 similar to swivel 24 the jack 45 of the second compression stage and an articulation axle 46 of the pendular arm 47 of the dynamic equilibration mass of said stage and at its lower side portion the articulation axle 48 of the crank of the connecting rod system which is a balance beam with two arms 49a 49b at the end of arm 49a are articulated via a swivel 50 the end of the rod 51 of jack 45 and a connecting rod 52 the other end of which is articulated via a swivel 53 to the end of the pendular arm 41 of piston 42 at the end of arm 49b is articulated a connecting rod 54 the other end of which is articulated to the free end of the pendular arm 47 of the equilibration mass at that.