Patent attributes
A system includes a compression spring having a latch sleeve, a piston rod including a groove section, and a ratchet assembly that progressively moves the piston rod in a downward direction. A latch collet on the latch sleeve sits on the groove section of the piston rod in a first position of the system. The latch collet locks a spring force of the compression spring as the ratchet assembly progressively moves the piston rod in the downward direction. The latch collet becomes unsupported from the groove section when the piston rod has progressively moved a predetermined distance, causing the compression spring to release and provide a push force that actuates a hydraulic valve from the first position to a second position.