SIGNALING APPARATUS

• US 3,614,760 A
• Filed: 12/27/1968
• Issued: 10/19/1971
• Est. Priority Date: 12/27/1968
• Status: Expired due to Term

• Current Assignee: Arthur L. Zimmet, Milton P. Chernack
• Original Assignee: Arthur L. Zimmet, Milton P. Chernack
• Inventors: Chernack, Milton P., Zimmet, Arthur L.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Trafton, David L.
• Application Number:
  US04/787,456
• Time in Patent Office: 1,026 Days
• Field of Search: 340/224,170 325/185 331/116,66,185
• US Class Current: 340/539.3
• CPC Class Codes: G08B 1/08 using electric transmission ; transformation of alarm signals to electrical signals from a different medium, e.g. transmission of an electric alarm signal upon detection of an audible alarm signal
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence

Abstract

A signaling system employs a transmitter energized by a momentary power generator which responds to a brief mechanical input. The input may be due to intentional signaling activity, unintentional triggering of a gurglar detection device, or it may be in response to an ambient condition such as elevated temperatures indicating a fire is in progress. The mechanical event vibrates a spring-mass pendulum. The vibrating mass traverses an airgap in a magnetic circuit to induce an alternating potential in a signal output coil. The output of this generator is rectified to provide power for one or more radio frequency transmitters, and in addition may be used as the modulating signal impressed upon the radio frequency carrier. Two radio frequency transmitters operating at different carrier frequencies may be modulated by different phase components of the generator frequency. Alternatively, the modulation may be supplied by one or more subcarrier generators energized by the mechanical power generator. For greater noise immunity, a variation of this system may employ coded combinations of subcarrier frequencies.

Claims

1. A device for generating an interference-resistant electrical alarm signal upon the occurrence of a predetermined event, comprising:

a. means for generating a relatively low frequency alternating signal including i. a magnetic circuit including a source of magnetic flux, ii. a coil in flux linking relationship with said magnetic circuit;

iii. mEans for varying the amount of flux linking said coil including an oscillatably mounted arm and means for setting said arm into oscillation, b. first and second R.F. transmitter means for simultaneously broadcasting at first and second carrier frequencies, respectively, said carrier frequencies being different;

c. a circuit connected to rectify said generator frequency alternating potential and to simultaneously supply the resulting unidirectional power for energizing said first and second R.F. transmitter means to simultaneously transmit signals at said carrier frequencies for a brief interval;

d. first means responsive to said generator to apply said generator frequency as a first modulation signal to modulate said first carrier frequency signal broadcast by said first transmitter means, second means responsive to said generator to apply said generator frequency out of phase with first modulation signal as a second modulation signal to modulate said second carrier frequency signal broadcast by said second transmitter means; and

e. means for latching said arm in a potential energy storing condition and for thereafter abruptly releasing it upon the occurrence of said event.

2. A device as in claim 1, further comprising means for moving said arm relative to said latching means for bringing said arm into latching engagement with said latching means.

3. A device as in claim 1 for detecting a fire, wherein said latching means comprises a bimetallic member for maintaining said latching means in position to latch said system below a threshold temperature, and for moving said latching means out of said latching position when said threshold temperature is reached.

4. A device as in claim 1, wherein said system vibrating means comprise a device for applying a sudden vibrating impulse to said system when said system is at rest upon the occurrence of said event.

5. A device as in claim 1, wherein source of magnetic flux is a permanent magnet mounted on said oscillatable arm for oscillation therewith, whereby to vary the amount of flux linking said coil.

6. A device as in claim 1, wherein said magnetic circuit comprises a highly permeable frame defining a pair of spaced-apart pole pieces, said coil is wound on said frame, said source of magnetic flux is a permanent magnet disposed between said pole pieces, said arm is resilient and is mounted at one end, said permanent magnet being mounted on the other end of said arm for oscillation therewith.

7. Signaling means as in claim 1 further comprising a receiver including:

means tuned to said first carrier frequency for detecting said first broadcast signal;

means tuned to said second carrier frequency for detecting said second broadcast signal;

controlled means; and

means connected to the outputs of both said first and second detecting means and selectively responsive to simultaneous outputs of said first and second modulation signals from said detectors to turn on said controlled means.

8. Signaling means as in claim 7, wherein;

said controlled means comprises an indicating device and a latching circuit connected to drive said indicating device; and

said modulation frequency-responsive means triggers said latching circuit in response to said simultaneous modulation signal outputs.

9. Signaling means as in claim 7 wherein;

said selectively responsive means comprises a phase-sensitive circuit selectively responsive to said simultaneous first and second respective modulation signal outputs from said detectors which are in substantially the phase relationship of said first and second modulating signals.

10. Signaling means as in claim 9, wherein said selectively responsive means comprises at least one filter connected at the output of one of said detectors for selectively passing said modulation signal.

11. Signaling means as in claim 9, wherein said selectively responsive means comprises;

means for squaring said modulation signal detector outPuts;

a circuit connected to delay the more advanced one of said squaring circuit outputs by a period substantially equal to said phase difference whereby to produce a substantially in-phase relationship;

means responsive to said in-phase relationship to generate transition markers; and

a gate connected to turn on said controlled means upon coincidence of said transition markers.