Operation of Uniport Valve

Five_Stages_of_the_Double Acting, Uniport Valve

       The following few paragraphs will explain how the Uniport Valve works with the help of the above views. Some of the arrows on these views show the direction of the exhaust and intake flow and they are marked on the view which represents the time frame for which the event occurs. The following paragraph will describe the parts while the paragraph after that is a view by view description of how these parts work together.

       Part A looks much like a standard poppet valve used in most engines. Part B is similar in shape except its stem is bigger around and the head is smaller. There is a hole bored through its stem so that the stem of part A may pass through it as shown. Part C  is shaped similar to a hollow cylinder which is free to move in a bore concentric with the other two moving parts. Note part C has two different seats ground on its end. The inner seat is made to seat with part B and the outer one is made to seat with the end of the intake runner. Part A is basically a typical poppet valve and it closes against the cylinder head in typical fashion closing off all flow.

       View 1 shows the position of the three moving parts just before the exhaust cycle begins. From there parts A and B move to the position you see in View 2, allowing exhaust gas to pass through part C and out through the exhaust passage. In View 3 you will see that part B has returned to a position which will stop all exhaust flow. As part B continues in the same direction, it moves part C so that the intake cycle can begin. The two continue to a point shown in View 4, which would be about halfway through the intake cycle. At the end of the intake cycle part A would have closed as shown on View 5 where it would stay during the compression and work cycles. During that time part B and C have roughly 250 degrees of crank angle to get to the position that was in shown in  View 1. Of course this completes a full cycle for a four-cycle engine.