Patent ID: 8794206

Claim:
An engine valve system comprising: two cams mounted coaxially, a summation rocker coupled to followers of both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams; a valve actuating rocker pivotably coupled to the summation rocker and operative to open an engine valve in dependence upon movement of the summation rocker, wherein the actuating rocker rests on a hydraulic lash adjuster; a control spring to urge the summation rocker in a direction to compress the hydraulic lash adjuster; and, a stop comprising an element of fixed maximum length acting upon the control spring to limit the movement of the summation rocker towards the lash adjuster so as to set a clearance in the valve system when the valve is closed and the cam followers are on base circles of the two cams; wherein the element of fixed maximum length is selected from a group comprising a telescopically collapsible strut, a cable and a chain, and wherein the element is coupled at a first end to the summation rocker and at a second end to a mounting point coupled to the engine block.