Door knob lock monitoring alarm mechanism

An interior door knob incorporating a lock monitoring alarm comprising in combination,

• an interior knob housing having a cylindrical receptacle and an integral cylindrical neck coaxially extending therefrom, the cylindrical neck including means for engaging and mechanically rotating a spindle opening a lockable door latch when the knob housing is turned,
• an actuator member extending from within the knob housing, through the cylindrical neck of the knob housing and mechanically coupled to a locking mechanism within the lockable door latch for preventing rotation of the spindle by an interior knob, the actuator member being mechanically moved between a lock position and an unlock position as the locking mechanism engages and disengages respectively,
• a source of electrical energy located within the interior knob housing having at least a pair of terminals, each electrically insulated from the other,
• a normally-open electrical switching means located within the interior knob housing and mechanically coupled to the actuator member for opening and closing said switching means responsive to the lock and unlock positions of the actuator member, respectively,
• electrically energized indicator means located within the interior knob housing for generating an audio output of at least 70 db at a frequency perceptible by human beings and for generating a light emission perceptible by human beings upon being energized with electrical energy,
• electrical current conducting means for electrically connecting the switching means and the indicator means in series between the terminals of the electrical energy source, whereby the indicator means is energized when the switching means is closed,
• a removable circular cap member closing the cylindrical receptacle of the knob housing and having an audio grill port and an optical port communicating through its closure surface.