The design included some revolutionary features, foremost of which was the "dashpot" - an oil-filled piston assembly designed to cushion the spring driven return of the main assembly.

The gears then compress a piston assembly against a spring.

Still others have magnets inside the cylinder, part of the piston assembly, that pull along magnets outside the cylinder wall.

Unscrew the end cap and use a screwdriver to lever out the piston assembly.

Many log splitters consist of a hydraulic or electrical rod and piston assembly and these are often rated by the tons of force they can generate.

The piston assembly does not experience any side force which will reduce wear and lubrication requirements at the cylinder contact.

So unless the engine is run at very low rotational speeds, the friction losses due to centrifugal forces acting on the piston assemblies can quickly become unacceptable.

The water pressure would drive a five-story-high piston assembly up and down.

The piston assembly is an even number of pistons arranged radially around a single crankshaft.

The piston assembly was the source of the most significant losses in an engine.