| 摘要 |
<p>A second latch for use on a door has the customary bolt retractable by turning an inner knob which is always free to rotate, and also by turning an outer knob when such outer knob is freed for rotation by the momentary axial depression by thumb pressure of a pin tumbler lock cyclinder located in the outer knob. When greater security is desired a push button in the inner knob can be moved to a hold position to prevent axial depression of the lock cylinder thereby preventing the release of the outer knob for rotation. The lock cylinder may be rotated at all times by a proper key in the customary manner for retracting the bolt.</p> |
