Four-cycle internal combustion engine without a camshaft

Claim 1

In a four-cycle internal combustion engine having at least one cylinder, a piston reciprocable within said cylinder and defining a chamber above said piston and within said cylinder undergoing the intake, compression, power, and exhaust strokes, and a valve configuration designed to operate without a camshaft, a first chamber upstream from and adapted to communicate with the space within said cylinder beneath said piston for conducting a fresh charge of aN air and fuel mixture to said cylinder and into the space beneath said piston, a second chamber downstream from and adapted to communicate with the space within said cylinder beneath said piston, first reed valve means between said upstream chamber and space in said cylinder beneath said piston operable in response to differential in gas pressures in said downstream chamber and cylinder below said piston during the compression and exhaust strokes of the operating cycle of said engine for admitting a fresh charge of said fuel and air mixture into said cylinder below said piston during the compression and exhaust strokes of the operating cycle of said engine, second reed valve means between said downstream chamber and space in said cylinder beneath said piston operable in response to the differential in gas pressures in said cylinder below said piston and downstream chamber during the intake and power strokes of the operating cycle of said engine for transferring the fresh charge of said fuel and air mixture introduced into the space in said cylinder beneath said piston during the compression and exhaust strokes of the operating cycle of said engine into said downstream chamber during the intake and power strokes of the operating cycle of said engine, inlet valve means in said cylinder above said piston in communication with said downstream chamber operative in response to a first gas pressure differential between said downstream chamber and cylinder above said piston during the intake stroke of the operating cycle of said engine for admitting the fresh charge of air and fuel mixture introduced into said downstream chamber during the previous intake and power strokes of the operating cycle of said engine into said cylinder above said piston, outlet valve means in said cylinder above said piston in communication with said downstream chamber operative in response to a second gas pressure differential between said downstream chamber and cylinder above said piston during the exhaust stroke of the operating cycle of said engine for expelling a burnt charge from said cylinder above said piston, an exhaust passage in communication with said outlet valve means for receiving said burnt charge expelled from said cylinder, and a normally closed pressure valve means between said exhaust passage and cylinder adapted to open in response to the pressure in said cylinder at the conclusion of the power stroke of said piston for relieving the gas pressure within said cylinder sufficiently to enable said second gas pressure differential in said downstream chamber to open said outlet valve means in preparation for the scavenging stroke of the engine cycle.