Internal combustion engine or pumping device

An internal combustion engine/pumping device comprising an engine block forming a pair of elongated coaxially arranged cylinders, each cylinder including a piston arranged for reciprocation therein and dividing the cylinder into a combustion chamber and a pumping chamber, means for injecting fuel into said combustion chamber, means for admitting air into said combustion chamber, exhaust means in communication with said combustion chamber, a low pressure fluid conduit in communication with said pumping chamber, a high pressure fluid conduit in communication with said pumping chamber, means for communicating pressurized transmission drive fluid from said pumping chamber into said high pressure fluid conduit during a power stroke of said piston, means for admitting transmission drive fluid from said low pressure conduit into said pumping chamber prior to said power stroke, means for communicating said high pressure fluid conduit with work means to be driven by operation of said engine, a mechanical coupling interconnecting said two pistons for operation of said two pistons in opposition to each other, said mechanical coupling comprising a rigid shaft interconnecting the two pistons, a second pair of similar elongated cylinders each including a piston dividing the respective cylinders into a combustion chamber and a pumping chamber, said second pair of cylinders and pistons being in coaxial alignment with each other, said pistons in said second pair of cylinders being interconnected by a rigid shaft, said two pairs of opposed pistons being arranged in parallel side-by-side relation and further comprising means interconnecting said two shafts for assuring synchronized reciprocating movement thereof in opposition to each other, said means interconnecting said two shafts comprising a synchronizing piston mounted upon each shaft and disposed for reciprocation within a synchronizing cylinder, fluid passages interconnecting the opposite ends of the two synchronizing cylinders.