Abstract: A completely enclosed combination clutch and brake mechanism permanently mounted at the bottom of a vertical shaft internal combustion engine of the type used to power rotary lawn mowers, is interposed between the crankshaft of the engine and a coaxial blade shaft projecting down from the bottom of the enclosed clutch and brake mechanism to have the cutting blade of the mower fixed thereto. A rotatable driving member fixed to the engine crankshaft and a rotatable driven member fixed to the blade shaft are drivingly coupled by radially outwardly movable clutch elements carried by the driven member and frictionally engaged with a radially inwardly facing circular surface on the driving member. Such frictional engagement results from the application to the clutch elements of both spring force and centrifugal force.

Abstract: A rotary engine of the trochoidal type in which the rotor and the profile of a basically trochoidally shaped inner housing wall bear such relationship to one another that when the differential in pressure in the flanking chambers is Greatest, the rotor apex seals are deliberately caused to stroke out, so that the resulting friction between the outwardly stroking apex seals and the sides of the rotor slots, so modifies the outward forces acting on the seals that the contact force between the seals and the housing wall are significantly less than they would be without such outward stroking of the apex seals.