| 摘要 |
<p>A latch has a latch bolt mounted on a rack and a top gear which engages the rack. The top gear can be driven by an idle gear which is disengageable from a drop gear which in turn is engaged with a lockable drive gear upon rotation of a cam disc. Initial rotation of the cam disc disengages the drop gear. Further rotation of the cam disc moves the top gear so as to permit the rack to move the bolt to the unlatched position. The latch can be operated from one side by the rotation of a lock plug in the drive. The other side of the latch has a tumhandle on the cam disc which unlatches the latch even when the drive gear is locked from the outside.</p> |
