US Patent 7681543 Tappet apparatus

A tappet apparatus cooperates with a valve and a cam. The apparatus includes a case to reciprocate motion of the cam; and a locking unit in the ease, movable between an activated position at which the valve reciprocates motion of the case, and a deactivated position at which the valve is stationary regardless of the motion of the case. The locking unit may include first and second passages in the case; a pin, movable between a first and a second position within the first passage; and a column in the second passage. The pin may be situated in the column when the pin is in the second position. The activated position may be defined by the pin being in the first position, and the deactivated position may be defined by the pin being in the second position.