| 摘要 |
This automatic double-action casement bolt comprises a pair of locking bars urged by resilient return means to a locking or bolting position in which the bars engage corresponding keepers, these bars being retracted from the keepers and moved to their unbolting position by a set of angular levers fulcrumed at their vertices on the casement bolt casing, each angular lever being connected through one arm to one of the sliding bars, each angular lever comprising, at the end of its other arm, a notch engageable by a catch of at least one control rod movable in a direction across the bars and formed integrally with an operating and control handle urged by other resilient means to its inoperative position, the notch of the other arm of each angular lever being formed in the edge of this arm so as to provide an open clearance of which the bottom constitutes a striking edge adapted, when the casement bolt is unbolted, to co-operate with the catch of the control rod. |
