US Patent 7293540 Valve operating assembly and method of manufacturing

The present invention relates to a leakdown plunger, comprising a first plunger opening, a second plunger opening, and an outer plunger surface that is provided with an axis and encloses an inner plunger surface, the first plunger opening is provided with a first annular plunger surface shaped to accommodate a valve insert, the second plunger opening is configured to cooperate with a socket body, the outer plunger surface includes a cylindrical plunger surface and cooperates with an engine workpiece, and the inner plunger surface includes an inner cylindrical plunger surface.