Patent ID: 8707916

Claim:
A split-cycle engine comprising: a first adjustable mechanical element associated with a first engine valve; a second adjustable mechanical element associated with a second engine valve; a trigger valve having: a closed position in which an outlet line hydraulically connected to the first adjustable mechanical element is hydraulically disconnected from an accumulator such that fluid is maintained in the first adjustable mechanical element and valve train motion is imparted through the first adjustable mechanical element to the first engine valve, and an open position in which the outlet line is hydraulically connected to the accumulator such that fluid is allowed to drain from the first adjustable mechanical element and valve train motion is not imparted through the first adjustable mechanical element to the first engine valve; and a spool valve having: an activated position in which the second adjustable mechanical element is hydraulically connected to the outlet line such that fluid is maintained in the second adjustable mechanical element when fluid is maintained in the first adjustable mechanical element and fluid is allowed to drain from the second adjustable mechanical element when fluid is allowed to drain from the first adjustable mechanical element, and a deactivated position in which the second adjustable mechanical element is hydraulically disconnected from the outlet line and is instead hydraulically connected to the accumulator such that fluid is allowed to drain from the second adjustable mechanical element regardless of whether fluid is allowed to drain from the first adjustable mechanical element.