Patent ID: 8720411

Claim:
A reciprocating piston engine comprising: a piston; a cylinder; a main combustion chamber which is formed between the piston and the cylinder; a pre-chamber having a pre-chamber axis; a riser passage arranged such that the main combustion chamber is in communication by way of the riser passage with the pre-chamber so that a gas-air mixture pushed by the piston from the main combustion chamber into the riser passage forms a rising flow in the pre-chamber; and a gas feed passage separate from the riser passage which opens into the pre-chamber, wherein the riser passage and the gas feed passage are oriented relative to each other such that gas fed into the pre-chamber by way of the gas feed passage impinges substantially frontally on to the rising flow, wherein the riser passage extends inclinedly relative to the pre-chamber axis, and wherein the riser passage is arranged such that the gas-air mixture forms a tumble flow in the pre-chamber.