An apparatus for deactivating an engine valve has an accumulator sleeve slidably
retained in an engine block and biased toward a lower chamber in fluid communication
with an interior of the sleeve. A follower piston slides in the sleeve in contact
with a lobe of a can. An upper piston slides in an upper chamber in contact with
a pushrod. A fluid passage connects the lower chamber and the upper chamber. A
normally open spool valve in the fluid passage includes a control spool for opening
and closing the passage. Another passage connects the lower chamber and one end
of the control spool. A spring chamber provides fluid to an opposite end of the
control spool through a control valve from a source of pressurized fluid.
