Engines, pumps and motors

Claim 1

In a fluid pump or motor or internal combustion engine of the kind comprising a crank shaft having an inclined working portion, first and second banks of cylinders at opposite ends of the crank shaft working portion, the cylinders in each bank being arranged around the crank shaft axis and facing the corresponding cylinders of the other bank with their axes parallel to the crank shaft axis, a set of piston rods each interconnecting a first piston in a cylinder of the first bank with a second piston in the corresponding cylinder of the second bank and a driving connection for each piston rod, the improvements which comprise: a first fluid connection, a first manifold chamber positionally associated with the first cylinder bank and serving both cylinder banks, said first fluid connection opening into said first manifold chamber, a second fluid connection, a second manifold chamber positionally associated with the second fluid connection opening into said second manifold chamber, first and second valve-controlled ports for each cylinder of each bank, the first ports of the first cylinder bank opening into said first manifold chamber, the second ports of the second cylinder bank opening into the second manifold chamber, first and second duct means extending between said first and second cylinder banks, said first duct means interconnecting the second valve ports of said first cylinder bank with said second manifold chamber, and said second duct means interconnecting said first valve ports of said second cylinder bank with said first manifold chamber.