| 摘要 |
<p>A valve gear comprising a housing provided with a passage, a valve member arranged within said housing, which is movable between a first, closed position, in which the passage is closed, and a second, open position, a piston connected to the valve member, which can oscillate in an at least substantially closed piston chamber, and locking means which are capable of holding the valve member periodically in the closed position, wherein the piston chamber is provided with at least three closable openings, which may each be in communication with gas pressure means, wherein the first opening and the second opening are each in communication with another part of the piston chamber separated therefrom by the piston, and which are open when the valve member is held in the closed position, and wherein the third opening is open during movement of the piston.</p> |
