in the region where the bypass channel 3 39 a is already wider as a result during a movement of the piston 4 toward the support plate 2 a considerable amount of the gas liquid mixture will flow through the bypass channel 3 39 a into the second and enlarging chamber which is forming behind the piston 4 thus the damping action of the binding becomes weaker with a tighter binding adjustment and with an increasing damping stroke a weak binding adjustment will initiate a stronger damping action since in such a case the action of the bypass channel 3 39 a gradually becomes unrestrictive to the flow of the gas liquid mixture therethrough the exemplary embodiment which is illustrated in fig9 and 10 is designed except for the bypass channel 3 34 a in the cylinder 3 34 the same as in the exemplary embodiment according to fig5 to 8 the bypass channel 3 34 a has in its first third portion starting from the end remote from the support plate 2 a continuously decreasing depth which in its second third portion transfers into a parallel section and in its last third portion into a continuously enlarging depth through this type of construction of the.