Patent ID: 8408172

Claim:
A variable valvetrain actuation device coupled to a camshaft lobe and a follower for actuating a combustion valve in an internal combustion engine, said device comprising: a control shaft having an axis of rotation and rotatably mounted to said engine, said control shaft fixed to a control shaft disc, said disc having a pivot center eccentric to said control shaft axis of rotation; an input rocker subassembly pivotably disposed on said control shaft disc, said input rocker subassembly having a contact feature disposed against said camshaft lobe, having a foot defined by said input rocker subassembly and having an input rocker pivot center coincident with said control shaft disc pivot center; an output cam subassembly pivotably mounted to said engine and engageable by said foot, said output cam assembly having an output cam profile for engaging said follower, an output cam pivot center locationally fixed with respect to said control shaft axis of rotation, a threaded bore having X threads per inch, and a shoe engageable by said foot of said input rocker subassembly, wherein when said control shaft is rotated about its axis of rotation, said input rocker pivot center is movable relative to said output cam pivot center; and an adjuster mechanism for varying the angular relationship of said input rocker subassembly to said output cam subassembly; wherein said adjuster mechanism comprises: a threaded stud defined by said shoe, said threaded stud having Y threads per inch; and an adjusting screw having internal threads and external threads wherein said adjusting screw internal threads are matable with said threads of said threaded stud and wherein said external threads are matable with said threaded bore of said output cam subassembly and wherein X does not equal Y numerically.