×

Door knob lock monitoring alarm mechanism

  • US 4,760,380 A
  • Filed: 08/27/1986
  • Issued: 07/26/1988
  • Est. Priority Date: 08/27/1986
  • Status: Expired due to Fees
First Claim
Patent Images

1. In a lockable door latch having turnable exterior and interior knobs for mechanically rotating a spindle for moving a door bolt in and out of engagement with a strike plate mounted in a door jamb, and having a manually operated interior mechanism for locking and releasing a locking mechanism, an interior knob incorporating a lock monitoring alarm comprising in combination,a knob housing having a cylindrical receptacle and an integral cylindrical neck coaxially extending therefrom, the cylindrical neck including means for engaging and mechanically rotating the spindle when the knob housing is turned,an actuator member extending from within the knob housing, through the cylindrical neck of the knob housing for mechanically engaging the locking mechanism, 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 knob housing having at least a pair of terminals, each electrically insulated from the other,a normally-open electrical switching means located within the knob housing and mechanically coupled to the actuator member for opening and closing responsive to the lock and unlock positions of the actuator member, respectively,an electrically energized indicator means located within the knob housing for generating a signal perceptible to a human being upon being energized with electrical energy,electrical current conductor 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.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×