It looks like the patent describes a weird hybrid of a conventional 4-stroke and a uniflow 2-stroke. At the bottom of the first power stroke, the cylinder drop

It looks like the patent describes a weird hybrid of a conventional 4-stroke and a uniflow 2-stroke. At the bottom of the first power stroke, the cylinder drops lower to expose scavenging ports. That both forces air in (at the bottom of the cylinder) and helps push exhaust out (through conventional exhaust valves). Uniflow 2-strokes tend to have high thermal efficiency, but poor emissions, especially particulates. So the idea here might be to gain some efficiency without another emissions-gate.