Ceiling fan proximity safety apparatus

Abstract

A apparatus for preventing the incursion of persons (i.e. hands) or objects into the path of rotating ceiling fan blades. The apparatus may be embodied as an aftermarket device or integrated within an aftermarket device or more preferably within the fan electronics themselves. In one embodiment the sensors span at least a large portion of the length of one or more fan blades. The distributed sensor is configured to detect proximity of persons, or persons and objects. By way of example the sensor may comprise an inductive loop, or capacitive sensing circuit. In response to absolute and/or changes in proximity annunciations are generated as audio and/or optical output thus alerting the individual to the incursion danger.

1 . An apparatus for generating incursion alerts when objects approach the blades of a ceiling fan, comprising: 
 means for electrically sensing proximity of objects to one or more blades of a ceiling fan;    means for generating an electrical alert signal in response to detecting a sufficient level of proximity, or sufficient level of proximity change, as detected by said sensing means; and    means for generating an annunciation from said ceiling fan in response to said alert signal.    
   
   
       2 . An apparatus as recited in  claim 1 , wherein said annunciation comprises an optical annunciator, audio annunciator, or a combination of optical and audio annunciators.  
   
   
       3 . An apparatus as recited in  claim 1 , wherein said means for sensing proximity comprises a proximity sensor.  
   
   
       4 . An apparatus as recited in  claim 3 , wherein said proximity sensor comprises a conductive pathway on at least one said blade of said fan, which is coupled to a sense circuit configured to generate a proximity signal in response to motion toward said fan blade.  
   
   
       5 . An apparatus as recited in  claim 4 , wherein said proximity sensor is configured for sensing a change in capacitance, inductance, or electric field intensity.  
   
   
       6 . An apparatus as recited in  claim 1 , wherein said means for detecting a sufficient level of proximity comprises a threshold detection circuit configured to generate an alert signal in response to a sufficient level of absolute proximity, or a sufficient change in proximity.  
   
   
       7 . An apparatus as recited in  claim 6 , further comprising a signal conditioning circuit for preparing the proximity sensor signals for said threshold detection circuit.  
   
   
       8 . An apparatus as recited in  claim 6 , wherein said threshold detection circuit includes is configured to compare signals relating to absolute proximity, changes in proximity, or a combination with threshold values.  
   
   
       9 . An apparatus as recited in  claim 1 , further comprising a user control coupled to said means for detecting proximity or said means for generating an annunciation to alter annunciative output in response to the setting of said user control.  
   
   
       10 . An apparatus as recited in  claim 9 , wherein said user control comprises a sensitivity adjustment.  
   
   
       11 . An apparatus as recited in  claim 9 , wherein said user control is configured to adjust the intensity of an optical annunciation, the volume of an audio volume adjustment, or a combination.  
   
   
       12 . An apparatus as recited in  claim 1 , wherein said means for generating an annunciation comprises an audio signal source coupled to an audio transducer, configured for generating audible alerts.  
   
   
       13 . A ceiling fan with blade incursion sensor, comprising: 
 at least one plurality of fan blades coupled to a hub;    a fan motor coupled for rotating said hub;    a motor controller circuit electrically coupled to said motor and configured for controlling the speed of said fan motor;    a proximity sensing element distributed over a portion of at least one of said ceiling fan blades;    a proximity threshold detection circuit coupled to said proximity sensing element configured to generate an alert signal in response to an absolute or relative proximity which exceeds a desired threshold; and    an annunciator coupled to said proximity deteection circuit and configured for generating an audible alert, optical alert, or combination of optical and audible alert in response to receiving said alert signal.    
   
   
       14 . A system for generating intrusion alarms in response to registered conditions, comprising: 
 an intrusion detector configured for registering conditions indicative of intrusion;    an alarm detection circuit within said intrusion detector for generating an alarm signal in response to a condition, or conditions, which exceed a first threshold;    wherein said alarm detection circuit is configured to generate a prequalification signal in response to conditions which exceed a second threshold but which does not exceed said first threshold, and    a controller circuit configured for coupling to at least two said intrusion detectors and configured to generate an audible and/or silent alarm in response to detecting an alarm signal from any detector, or in response to the receipt of more than one prequalification signal.    
   
   
       15 . A system as recited in  claim 14 , wherein said more than one prequalification signal must be generated from different intrusion detectors as a condition for generating said alarm.  
   
   
       16 . A system as recited in  claim 15 , wherein said intrusion detector comprises means for unit identification within said system, allowing said controller circuit to distinguish which intrusion detector transmitted a given prequalification signal.  
   
   
       17 . A system as recited in  claim 14 , wherein said controller circuit is configured to register the receipt of said prequalification signal and to extend the applicability of the prequalification over a predetermined or variable period of time when determining if more than one prequalification signal is being received.  
   
   
       18 - 203 . (canceled)