|6784784||Request to exit switch for door alarm system|
A door alarm system and a door lock assembly having an interior rose having a request to exit (REX) switch. The alarm system generates an open door alarm when a door into a secured area is open unless the REX switch generates a REX signal indicating that the door wa...
|4800833||Tubular door lock with a bell|
A sort of tubular door lock whose inside knob or outside knob can be forced to rotate by each other's rotation and force a rotating unit to turn pushing and overpassing a projection of a knocking spring to get the knocking points at its both ends to knock...
|4577584||Bell lock (II)|
An improved knob lock commonly used, which comprises a bell inside. The main part of which is a rotator which is turned by rotating either of the knobs and has two extending-out springs to which are attached a steel ball respectively at their ends. Hindra...