| 摘要 |
Apparatus for machining the annular valve seats of a gate valve has a cradle which slides on and wedges outward against the confronting gate guide rails in the valve chamber to lock the cradle in place between the valve seats. A large gear is mounted on one side of the cradle for rotation by a hydraulic motor about an axis generally aligned with the axis of the facing valve seat through adjustment of a pair of leveling screws. A carriage is driven axially on guide rods projecting from the gear adjacent the periphery thereof by a servo motor mounted in the plane of the gear. A tool carrier is reciprocated radially on slides on the carriage by a lead screw motor mounted on the carriage. When machining of one valve face is completed, the cradle is unlocked, lifted off the guide rails, rotated 180.degree. about a vertical axis and reinstalled on the guide rails for machining of the other valve seat. |
