Abstract: The combustion chamber of an internal combustion engine is provided with a vent passage. The passage is normally closed by a valve which opens in response to an opening pressure having a predetermined magnitude intermediate the magnitude of the normal combustion pressure and the pressure at which detonation occurs. The passage and the valve may be carried by either the permanent portion of the engine or a replaceable portion, such as a spark plug.

Abstract: This relates to a synchronizing clutch for use in a split crankshaft engine of a type which includes a main crankshaft section and at least one auxiliary crankshaft section. An input section is fixedly coupled to a first end of the main crankshaft section and drives a clutch plate. First and second engagement plates are rotatably coupled on the input section and each include at least first and second apertures. The first aperture in the first engagement plate resides in a different orbit than that of the second aperture. A pin plate is fixedly coupled to an adjacent end of the auxiliary crankshaft section and is provided with first and second pins which correspond in orbit to that of the first and second apertures in the first engagement plate. Actuation means are provided for disengaging the clutch plate and substantially reducing the speed of the second engagement plate to permit insertion of the first and second pins into slots in the second engagement plate.

Abstract: A power shaft is journalled within a stationary housing having a cylinder formed therein. The axis of the cylinder is radial to the axis of the power shaft. A lever arm pivotally carried by the housing is linked by a connecting rod to a piston slidably disposed within the cylinder. A crankplate rotatable with the power shaft supports a cam follower which intermittently interacts with the camming surface on the lever arm to urge the piston through the intake and compression cycles. During the power stroke of the piston, the lever arm pushes against the cam follower, causing rotation of the crankplate. In an alternate embodiment, a wrist pin having a radially extending rod is rotatably carried by the crankplate. Gear means provide timed rotation of the rod to periodically contact and interact with the piston. Either embodiment may include a plurality of radially spaced pistons and additional respective cam followers or wrist pins. Each cam follower or wrist pin may receive several power impulses per revolution.