277,108. Schieferstein, G. H. June 10, 1926. Machinery, utilizing inertia to obtain movements in.-In a, mechanical system for the transmission of power in oscillating form from a rotary crank or the equivalent to a rocking bell or other oscillating member of pronounced natural frequency, embodying a " loose coupling " or yield. ing connection adapted to transmit relatively y large amounts of energy whilst the oscillating member is gaining momentum and relatively small amounts of energy when said member is oscillating normally, the loose coupling comprises a piston displaceable in a cylinder containing both a liquid and a gaseous medium on each side of the piston, communication between the liquid on opposite sides of the piston being established by means of apertures in the piston or a passage in the cylinder walls. A bell 1 suspended on a pivot 2 carries arms 3 connected through " loose " or yielding couplings 14 to a pair of oppositely rotating cranks 9 driven through toothed gearing 81, 8 from a countershaft 12 connected by a belt 11 to a motor 10. Each loose coupling is adjustably connected to the crank 9 and arm 3 and comprises a piston rod 21 with an apertured piston 23 in a cylinder 16 containing glycerine or other liquid 24 and provided at its upper end with an air space 29 bounded by an inner sieeve 30. An air space 28 limited by a stop 27 is also provided in the tubular piston rod. The apertures in the piston may be throttled as required by a superposed apertured disc 25 carried by a sleeve 20 and adjustable, by means of hand grips 31, 32. Ball valves 26 on the piston are provided to compensate for dissymmetry of action due to varying displacement of the piston rod. When starting and stopping, the piston produces a strong damping effect whilst the air cushions are compressed. When normal oscillation has been established, the air cushions alone are operative.