Patent US2248447A successfully refreshed from Google Patents.
Patent US4401969A successfully refreshed from Google Patents.
US4401969A
Expired / Lapsed
US
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Traffic control system
Assignee: Individual
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Filing: 1981-10-08
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Granted: 1983-08-30
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Expires: 2001-10-08
Abstract
Abstract In a portable traffic control system in which receivers are controlled from a central transmitter the carrier signal employed is modulated by two different modulation signals in order to command a green light to be shown, reducing the possibility of this happening accidentally. The receipt of a carrier signal with only a single pilot modulation causes production of a red signal. An amber caution light if present is lit automatically upon turning off green, and flashing amber is produced by switching on green and then turning it off before the green can be lit. A drop in battery voltage below a predetermined level will cause a flashing red signal to warn and conserve the battery power. A non-resettable link in circuit with the green light is broken upon existence of a malfunction condition whereby another light is lit while green is alight, so that the green can no longer be lit until the unit is serviced to remove the malfunction.
Inventors
- 👤 Gordon J. Green
- 👤 Robert J. deBruyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:15
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/07; G08G1/097
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
312 words
A traffic control system comprising: (A) a transmitter unit including: (1) circuit means for transmitting a carrier signal (2) circuit means for selectively modulating the carrier signal with a first modulation signal at a first frequency, and (3) circuit means for selectively modulating the carrier signal with a second modulation signal at a second frequency different from the first frequency, and (B) a receiver unit for receiving the transmitted carrier signal and any modulation thereof by said first and second modulation signals and adapted to produce in response to receipt of the carrier signal modulated by both modulation signals and in cyclic sequence display of green, amber and red visual traffic signals, the receiver including: (1) a first detector detecting the said first modulation signal and producing a corresponding first control signal, (2) a second detector detecting the said second modulation signal and producing a corresponding second control signal, and (3) receiver circuit means requiring receipt of both said first and second control signals, for longer than a predetermined period and responsive to such receipt to cause display of the green visual traffic signal, (C) wherein the transmitter includes circuit means for generating a pulse of the said carrier modulated by said first and second modulation signals, which pulse is of a period shorter than the said predetermined period required for the said display of the green visual signal, and wherein the receiver circuit means is responsive to receipt of both said first and second control signals for a period longer than the said pulse to cause the said display of the green visual signal, is responsive to cessation of receipt of at least one of said control signals to cause display of the amber visual signal, and is responsive to receipt of the said pulse to cause display of the amber visual signal without prior display of the green visual signal.
Claim 2
Dependent Claim
312 words
A traffic control system comprising: (A) a transmitter unit including: (1) circuit means for transmitting a carrier signal (2) circuit means for selectively modulating the carrier signal with a first modulation signal at a first frequency, and (3) circuit means for selectively modulating the carrier signal with a second modulation signal at a second frequency different from the first frequency, and (B) a receiver unit for receiving the transmitted carrier signal and any modulation thereof by said first and second modulation signals and adapted to produce in response to receipt of the carrier signal modulated by both modulation signals and in cyclic sequence display of green, amber and red visual traffic signals, the receiver including: (1) a first detector detecting the said first modulation signal and producing a corresponding first control signal, (2) a second detector detecting the said second modulation signal and producing a corresponding second control signal, and (3) receiver circuit means requiring receipt of both said first and second control signals, for longer than a predetermined period and responsive to such receipt to cause display of the green visual traffic signal, (C) wherein the transmitter includes circuit means for generating a pulse of the said carrier modulated by said first and second modulation signals, which pulse is of a period shorter than the said predetermined period required for the said display of the green visual signal, and wherein the receiver circuit means is responsive to receipt of both said first and second control signals for a period longer than the said pulse to cause the said display of the green visual signal, is responsive to cessation of receipt of at least one of said control signals to cause display of the amber visual signal, and is responsive to receipt of the said pulse to cause display of the amber visual signal without prior display of the green visual signal.
Claim 3
Dependent Claim
38 words
A traffic control system as claimed in claim 1, wherein the said receiver circuit means is responsive to receipt of only either said first or said second modulation signal to cause display of the red visual traffic signal.
Claim 4
Dependent Claim
55 words
A traffic control system as claimed in claim 2, wherein said receiver circuit means is operative upon receipt of only said second control signal to cause display of a steady red visual traffic signal, and is operative upon receipt of only said first control signal to cause display of a flashing red visual traffic signal.
Claim 5
Dependent Claim
70 words
A traffic control system as claimed in claim 1, wherein the said receiver circuit means includes delay means to which at least one of the first and second control signals are fed to initiate display of the green visual signal, the said delay means delaying the application of the respective signal and thereby delaying display of the green visual signal for a period of time longer than the said pulse.
Claim 6
Dependent Claim
49 words
A traffic control system as claimed in claim 1, wherein the receiver circuit means includes a timer initiated in a timing cycle by cessation of said receipt of at least one of the said control signals to control the length of time of display of the amber visual signal.
Claim 7
Dependent Claim
31 words
A traffic control system as claimed in claim 1, wherein the receiver circuit means is responsive to cessation of the first control signal to terminate display of the amber visual signal.
Claim 8
Dependent Claim
82 words
A traffic control system as claimed in claim 1, wherein the receiver circuit means includes, a green control circuit portion producing a green enabling signal for display of the green visual signal, and a red control circuit portion producing a red enabling signal for display of the red visual signal, and wherein the green enabling signal is fed to the red control circuit portion to prevent the display of the red visual signal, until the green visual signal is no longer displayed.
Claim 9
Dependent Claim
102 words
A traffic control system as claimed in claim 1, wherein the receiver circuit means includes, a green control circuit portion producing a green enabling signal for display of the green visual signal, an amber control circuit portion producing an amber enabling signal for display of the amber visual signal, and a red control circuit portion producing a red enabling signal for display of the red visual signal, and wherein the green and amber enabling signals are fed to the red control circuit portion to prevent display of the red visual signal until the green and amber visual signals are no longer displayed.
Claim 10
Dependent Claim
129 words
A traffic control system as claimed in claim 1, wherein the receiver circuit means includes, a green control circuit portion producing a green enabling signal for display of the green visual signal, and a green off signal as the green visual signal is no longer displayed, an amber control circuit portion producing an amber enabling signal for display of the amber visual signal, and a red control circuit portion producing a red enabling signal for display of the red visual signal, and wherein the green off signal is fed to the red control circuit portion to prevent display of the red visual signal for a period after the green visual signal is no longer displayed and during which period the amber visual signal is displayed in a flashing operation.
Claim 11
Dependent Claim
98 words
A traffic control system as claimed in claim 1, wherein the receiver unit includes: a non-resettable circuit operating member electrically connected in series with the green visual signal for passage therethrough of the current required to display the green visual signal, circuit means connected to the non-resettable member and responsive to display of the red visual signal while the green visual signal is displayed to apply to the member an additional current sufficient to activate the non-resettable member to open the circuit including the green visual signal so that the green visual signal can no longer be displayed.
Claim 12
Dependent Claim
61 words
A traffic control system as claimed in claim 10, wherein said non-resettable member is a fusible link, and said circuit means connected to the member comprise an SCR device having an electrode thereof connected to the fusible link in parallel with the green visual signal, and having its gate electrode supplied with control current while the red visual signal is displayed.
Claim 13
Dependent Claim
102 words
A traffic control system as claimed in claim 1, wherein the receiver unit includes, a non-resettable circuit member electrically connected in series with the green visual signal for passage therethrough of the current required to display the green visual signal, circuit means connected to the non-resettable member and responsive to cessation of the said first control signal to apply to the member after a predetermined interval an additional current sufficient to actuate the member to open the circuit including the green visual signal if the green visual signal is still displayed so that the green visual signal can no longer be displayed.
Claim 14
Dependent Claim
102 words
A traffic control system as claimed in claim 1, wherein said receiver unit includes, a green control circuit portion causing a green enabling signal for display of the green visual signal, a red control circuit portion causing a red enabling signal for display of the red visual signal, and a generator operating at a predetermined frequency to feed a control signal to the red control circuit portion to display the red visual signal and flash it at said predetermined frequency, and to feed an inhibit signal to the green control circuit portion to ensure that the green visual signal is not displayed.
Claim 15
Dependent Claim
52 words
A traffic control system as claimed in claim 13, wherein said receiver unit includes circuit means for detecting the voltage of a power supply for the receiver, said circuit means being responsive to reduction of said voltage below a predetermined value to actuate the said generator and flash the red visual signal.
Claim 16
Dependent Claim
201 words
A traffic control system comprising: (A) a transmitter transmitting a control signal for control in a receiver of the display by the receiver in cyclic sequence of green, amber and red visual traffic signals, and (B) at least one said receiver receiving the said control signal and responsive thereto to cause the said dispaly; (C) the transmitter including circuit means for generating and transmitting a green form of said control signal adapted to cause display by each said receiver receiving the said green form control signal of said green visual signal, and for generating and transmitting a pulse of said green form of the control signal of period considerably shorter than that required for said cyclic display of the green visual signal; (D) each said receiver including circuit means responsive to receipt of said green form of the control signal for a period longer than the said pulse to cause the said cyclic display of the green visual signal, responsive to cessation of said green form of the control signal to cause display of the amber visual signal, and responsive to receipt of said pulse to cause display of the amber visual signal without prior display of the green visual signal.
Claim 17
Dependent Claim
201 words
A traffic control system comprising: (A) a transmitter transmitting a control signal for control in a receiver of the display by the receiver in cyclic sequence of green, amber and red visual traffic signals, and (B) at least one said receiver receiving the said control signal and responsive thereto to cause the said dispaly; (C) the transmitter including circuit means for generating and transmitting a green form of said control signal adapted to cause display by each said receiver receiving the said green form control signal of said green visual signal, and for generating and transmitting a pulse of said green form of the control signal of period considerably shorter than that required for said cyclic display of the green visual signal; (D) each said receiver including circuit means responsive to receipt of said green form of the control signal for a period longer than the said pulse to cause the said cyclic display of the green visual signal, responsive to cessation of said green form of the control signal to cause display of the amber visual signal, and responsive to receipt of said pulse to cause display of the amber visual signal without prior display of the green visual signal.
Claim 18
Dependent Claim
60 words
A traffic control system as claimed in claim 15, wherein each said receiver circuit means includes delay means to which the said green form of the control signal is fed to initiate display of the green visual signal, the said delay means delaying the display of the green visual signal for a period of time longer than the said pulse.
Claim 19
Dependent Claim
48 words
A traffic control system as claimed in claim 15, wherein each said receiver circuit means includes a timer initiated in a timing cycle by cessation of receipt of said green form of the control signal to control the length of time of display of the amber visual signal.
Claim 20
Dependent Claim
83 words
A traffic control system as claimed in claim 15, wherein each said receiver circuit means includes, a green control circuit portion producing a green enabling signal for display of the green visual signal, and a red control circuit portion producing a red enabling signal for display of the red visual signal, and wherein the green enabling signal is fed to the red control circuit portion to prevent the dispaly of the red visual signal until the green visual signal is no longer displayed.
Claim 21
Dependent Claim
103 words
A traffic control system as claimed in claim 15, wherein each said receiver circuit means includes, a green control circuit portion producing a green enabling signal for display of the green visual signal, an amber control circuit portion producing an amber enabling signal for display of the amber visual signal, and a red control circuit portion producing a red enabling signal for display of the red visual signal, and wherein the green and amber enabling signals are fed to the red control circuit portion to prevent display of the red visual signal until the green and amber visual signals are no longer displayed.
Claim 22
Dependent Claim
130 words
A traffic control system as claimed in claim 15, wherein each said receiver circuit means includes, a green control circuit portion producing a green enabling signal for display of the green visual signal, and a green off signal as the green visual signal is no longer displayed, an amber control circuit portion producing an amber enabling signal for display of the amber visual signal, and a red control circuit portion producing a red enabling signal for display of the red visual signal, and wherein the green off signal is fed to the red control circuit portion to prevent display of the red visual signal for a period after the green visual signal is no longer displayed and during which period the amber visual signal is displayed in a flashing operation.
Claim 23
Dependent Claim
102 words
A traffic control system as claimed in claim 15, wherein each said receiver unit includes, a non-resettable circuit operating member electrically connected in series with circuit means of the green visual signal for passage therethrough of the current required to display the green visual signal, circuit means connected to the non-resettable member and responsive to display of the red visual signal while the green visual signal is displayed to apply to the member an additional current sufficient to activate the member to open the circuit means of the green visual signal so that the green visual signal can no longer be displayed.
Claim 24
Dependent Claim
110 words
A traffic control system as claimed in claim 15, wherein each said receiver unit includes, a non-resettable circuit member electrically connected in series with circuit means of the green visual signal for passage therethrough of the current required to display the green visual signal, circuit means connected to the non-resettable member and responsive to cessation of the green form of the said control signal to apply to the member after a predetermined interval an additional current sufficient to actuate the member to open the circuit means of the green visual signal if the green visual signal is still displayed so that the green visual signal can no longer be displayed.
Claim 25
Dependent Claim
103 words
A traffic control system as claimed in claim 15, wherein each said receiver unit includes, a green control circuit portion causing a green enabling signal for display of the green visual signal, a red control circuit portion causing a red enabling signal for display of the red visual signal, and a generator operating at a predetermined frequency to feed a control signal to the red control circuit portion to display the red visual signal and flash it at said predetermined frequency, and to feed an inhibit signal to the green control circuit portion to ensure that the green visual signal is not displayed.
Claim 26
Dependent Claim
53 words
A traffic control system as claimed in claim 15, wherein each said receiver unit includes circuit means for detecting the voltage of a power supply for the receiver, said circuit means being responsive to reduction of said voltage below a predetermined value to actuate the said generator and flash the red visual signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |