VEHICLE PROXIMITY ALERTING MEANS

• US 3,854,119 A
• Filed: 08/11/1972
• Issued: 12/10/1974
• Est. Priority Date: 08/11/1972
• Status: Expired due to Term

• Current Assignee: Benjamin Friedman, Guy E. Adams
• Original Assignee: Benjamin Friedman, Guy E. Adams
• Inventors: Friedman, Benjamin, Adams, Guy E.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/279,993
• Time in Patent Office: 851 Days
• Field of Search: 340/22,32,33,34,258D,311,328,329 325/29,64,62,364 343/5PD,7ED,112CA 333/7R
• US Class Current: 340/902
• CPC Class Codes: B61L 29/246 Signals or brake- or lighting devices mounted on the road vehicle and controlled from the vehicle or train
• CPC Class Codes: G08G 1/161 Decentralised systems, e.g. inter-vehicle communication

Abstract

This invention relates to a system for alerting vehicles of the ground, air and water type of the closing proximity and immediate proximity of other such vehicles and more particularly comprises means to receive and detect amplitude modulated signals and identify them to operate switching means for alerting devices such as audio means and visual means such as light emitting diodes, panel displays or neon lights in accordance with the amplitude of said signals within a predetermined signature pass band in a periodic manner which is related to a separation range of the vehicles.

Claims

1. In a vehicular system for enabling vehicular proximity warning to be accomplished in accordance with an amplitude modulated signal, the combination comprising:

transmitter means carried by one vehicle, said transmitter means sending the amplitude modulated signal of a predetermined carrier frequency with a modulation signature;

receiver means carried by a second vehicle, said receiver means being adapted to receive and detect said amplitude modulated signal of a predetermined carrier frequency and modulation signature as transmitted by said transmitter means;

resonator circuit means tuned to a predetermined pass band to provide a positive potential when identifying said signal and a negative potential otherwise to operate switching means in said resonator circuit means, said resonator circuit means being connected to means to control an output of said switching means in accordance with the strength of said amplitude modulated signal as received by said receiver means;

a power source for energizing said receiver means and for providing energy to said resonator circuit means and said means to control output of said switching means; and

alerting means connected to said power source and said resonator circuit means and said means to control the output of said switching means to be operated thereby to provide range information to said second vehicle in reference to the proximity of said first vehicle.

2. In a vehicular system for enabling vehicular proximity warning according to claim 1 wherein said receiver means includes an antenna, a radio receiver and detector providing a current from said power source and said resonator circuit further includes a coupling transformer that is operated by said current provided by said detector for actuation of said resonator circuit when said detector detects said predetermined carrier frequency.

3. In a vehicular system for enabling vehicular proximity warning according to claim 2 wherein the means to control the output of switching means includes an amplitude detecting circuitry interposed between the switching means and the alerting means connected to the receiving means so as to operate the alerting means in a periodic manner whose off-period decreases as said signals from said transmitting means become closer-in to said receiving means until a predetermined closeness is reached whereby said alerting means is held-on until one or the other or both of said first or second vehicles begin to increase the range between them.

4. The structure of claim 3 wherein said alerting means is a combination of audio and visual means connected in parallel.

5. The structure of claim 2 and further characterized by having the resonator circuit comprised of a series impedance including an inductance and a capacitor with a center tap for the inductance connecting same across a secondary winding of the coupling transformer.

6. The structure of claim 5 wherein said alerting means is a combination of audio and visual means connected in parallel.

7. The structure of claim 1 wherein the means to control an output of said switching means is further characterized as an amplitude detector having a unijunction transistor connected to said switching means whose output is improved by an NPN transistor connected directly to said alerting means.

8. The structure of claim 7 wherein the amplitude detector is further characterized as including a variably conductive transistor between said alerting means and said power source.

9. The structure of claim 8 wherein the variably conductive transistor is connected to said unijunction transistor by an RC network and to said receiver means by a variable resistor.

10. The structure of claim 9 wherein the alerting means is a combination of an audio and visual means connected in parallel.

11. The structure of claim 9 wherein the signals from said receiver means are filtered by a capacitor circuit to require a strength which represents a range of a predetermined closeness before the actuation of the alerting means commences.

12. The structure of claim 11 wherein the alerting means is a combination of audio and visual means connected in parallel.

13. The structure of claim 1 wherein said alerting means is a combination of audio and visual devices connected in parallel.

14. Apparatus to receive amplitude modulated signals and detect those of a predetermined carrier frequency and modulation signature for operating a device, said apparatus comprising:

a frequency discriminator operatively connected to said means to receive and detect, said discriminator including means and circuitry to identify said signals within a predetermined pass band to provide in such case an output of a positive potential if within the pass band and a negative potential if without said pass band;

amplitude detection means connected to said means to receive and detect, said amplitude detection means being connected by a capacitor circuit connected to a variable resistor connected to a transistor means whereby said amplitude detection means is operative to function as a result of said signals when said signals are of a predetermined strength to pass said transistor means whereby said signals as pass are representative of a predetermined distance from the source thereof;

a semiconductor circuit operatively connected to said frequency discriminator to be controlled thereby to be biased on by a positive potential and off by a negative potential;

means connecting said amplitude detector and said semiconductor circuit to the device to operate the device in a pulsating or steady manner in accordance with signal pulses from said transistor means; and

a power source for said apparatus.

15. The structure of claim 14 wherein the frequency discriminator includes a resonator circuit tuned to a predetermined pass band.

16. The structure of claim 15 and further characterized by said means including a unijunction transistor having one base connected to said semiconductor circuit and another base connected to an NPN transistor connected between the device and the power source.

17. The structure of claim 16 wherein said semiconductor circuit comprises a Schmidt trigger whose output is connected to the unijunction transistor and a Darlington amplifier receiving the potential from said frequency discriminator for the control of said Schmidt trigger.

18. The structure of claim 17 wherein the resonator circuit comprises a series impedance with an inductance thereof center tapped by a conductor connected to the frequency discriminator circuit so as to provide a negative potential to the base of the Darlington amplifier when said signals are without the predetermined pass band.

19. The structure of claim 18 wherein the device is a combination of visual and audio means.

20. The structure of claim 14 wherein the device is a combination of parallel connected audio and visual means.

21. In connection with a coupling transformer actuated by signals from a radio receiver means, in a vehicular proximity warning system a frequency discriminator connected to a secondary winding of the coupling transformer, said frequency discriminator comprising:

a series impedance connected to one side of said secondary winding;

a first conductor leading from the other side of said winding;

a second conductor leading from the series impedance to a first output terminal;

a third conductor leading from the series impedance to a second output terminal;

a first resistance and capacitance means connecting said first conductor and said second conductor;

a second resistance and capacitance means connecting said first conductor and said third conductor;

a wave form smoothing capacitance connected between said second and third conductors; and

a fourth conductor tapped to said series impedance and said first conductor whereby the potentials at said first output terminal and said second output terminals may be changed in accordance with resonance of said series impedance.

22. The structure of claim 21 wherein said series impedance comprises a capacitor and an inductor that is center tapped by said fourth conductor.