AU672704B2 - Traffic warning device - Google Patents

Description

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Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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ir r i rr Name of Applicant: Actual Inventor: Address for Service: JEFFREY HERBERT SCHOLES JEFFREY HERBERT SCHOLES KEN MADDERN PATENT ATTORNEY, Floor, 150 Grenfell Street, Adelaide, South Australia, 5000 Invention Title: "TRAFFIC WARNING DEVICE" Details of Associated Provisional Application No: PL 9824 dated 7th July 1993 The following statement is a full description of this invention, including the best method of performing it known to the applicant.

-1- L This invention relates to a traffic warning device.

It is well known that work gang sites on roads or highways are danger spots, and for example, in the United States of America, some seven hundred (700) deaths occur annually due to accidents at such locations. Many attempts have been made to ascertain the reasons for accidents, and some attempts have been made to render such sites safer for workers. For example, in Victoria, Australia, a syndicate was appointed to study the danger which existed, and the following report was issued in 1990 under the title, "Influencing Road User' Behaviour Through Road works": .10 "For many years Vic Roads road workers and supervisors have been concerned about the excessive speed of road users travelling through road work sites. Approximately one hundred and sixty (160) casualty accidents are reported annually at an estimated cost to the community of seven million dollars (AU$7,000,000.00). The study methodology comprised: a literature search; a Vic Roads Road worker Survey; a Road User Survey; Collection of Accident and Workcare Statistics; and Iterviews of Professional People from both within VicRoads and external companies (eg RACV). Initiatives are described involving: long distance advance signs; signs at road works sites; appropriate signing of bituminous surfacing works; variable message signs; municipal signing; traffic controller; enforcement; work methods; training; and public education.

This invention is directed to improvements wherein motorists would bG warned of excessive speed within a speed restricted area, and further monitor unit means for workers and pedestrians and all workers of oncoming dangers.

Various adaptations may be implemented, for example, cameras to provide evidence in the incidence of an accident.

Briefly, in this invention, use would normally be made of either one of two speed monitors and one audio alarm, the speed monitors being of the sonar, laser or preferably radar type which would indicate to a motorist that he was travelling too fast and requesting that he slow down, and the audio alarm could, for example, be located at the workgang site so that the workgang would be warned of an oncoming vehicle which had not slowed down sufficiently at the locality of the speed monitors.

More specifically, the invention comprises a traffic warning device having at least one source of electrical energy, a speed monitor circuit, an alarm circuit, and an electrical link between said circuits; the speed monitor circuit comprising an (or the) energy source, a speed measuring device, a speed trigger threshold control, a comparator and an electrically operated sign so interconnected that when data emanating from the speed measuring device which represents the speed of the vehicle exceeds a set threshold voltage, the speed monitor circuit activates the sign; the alarm circuit also comprising an (or the) energy source, an alarm control circuit and an audible alarm, the audible alarm being activated by the alarm control circuit, itself being activated by the speed monitor circuit simultaneously with the sign.

The sign can for example, flash on the words "TOO FAST, SLOW DOWN" upstream of the workgang site.

However, the invention is not necessarily limited to just signs for workgang safety, and signs may be used for other purposes associated with road use by vehicles driven by members of the public.

An embodiment of the invention is described hereunder with reference to and is illustrated in the accompanying drawings in which: Fig 1 is a plan view showing a road which would carry traffic in two directions, speed monitors, audio alarm and the workgang site; Fig 2A is a block diagram of the speed monitor circuit; V II~L-L-I III Fig 2B is a block diagram of the audio alarm circuit which also has a secondary function of indicating any failure in the system; Fig 3 is a "exploded" diagrammatic drawing which shows the mechanism of activating the sign; and Fig 4 is a front elevation of the sign.

Referring first to Fig 1, a workgang site 10 has an audio alarm 11 U nearby, there being an electrical connection between the audio alarm and two speed monitors 12, each of which is located downstream from a respective speed restriction sign 13.

Although it is possible to utilise radar, sonar or '.aser energy for measuring the speed of a motor vehicle, radar is preferred since it is less prone to malfunction (due to dust in the air) than laser, and it is very seldom that there is so much dust in the air that sonar would be required.

However, all speed measuring devices whether they be sonar, laser or 5 radar have an output which is dependant upon vehicle speed, and in this invention use is made of that voltage to compare it with a voltage which can be i- set to provide a trigger or threshold control. For example, a comparator is used which will receive voltage from the speed measuring device which may be volts corresponding to 50 kph or 4 volts corresponding to 40 kph, and the threshold control can have its voltage set at 4 volts. Thus if the oncoming vehicle is travelling at a speed greater than 40 kph, the comparator will activate the flashing lamp and/or display sign. This is illustrated in Fig 2A wherein the speed measuring device 16 comprises a radar "gun" which receives energy from an energy source 17 (comprising a bank of batteries and/or solar cells), and the output of the speed measuring device 16 is fed into a comparator 18 and compared with a preset threshold control voltage 19. If the threshold control voltage 19 exceeds the output voltage of the speed measuring device 4 16, the comparator 18 changes state and activates an overspeed warning sign, being a flashing lamp 74 and display sign 71.

As shown in Fig 2B, an audio alarm general circuit 24 performs the dual function of providing control of an audio alarm 25, and this needs to be electrically coupled to both speed monitors. Since the speed monitors may be located some distance away from the workgang site, in this embodiment the electrical coupling 26 between each transmitter 27 and the receiver 28 is a radio frequency coupling, the frequency of each differing from that of the other, and comprising transmitter 27 in the monitor circuit and also receiver 28 in the 10 audio alarm general circuit 24. To avoid malfunction due to spurious signals, there is provided a code generator 29 which will transmit a code through modulator 30 to the receiver 28.

The code being transmitted would be in accordance with prior art as I follows: 15 If digital, a logic signal would be transmitted to the modulator 30 wherein it would be converted to serial form by the modulator for transmission purposes. Digital codes are preferred because of security, but an analogue Scode is less costly and could for example constitute a 1 kHz tone combined at the modulator 30 with the data signals from the data switch 20 and transmitted, 20 received and filtered out by the watchdog timer 33 in the audio alarm general circuit 24.

Fig 4 illustrates the energy source 17 constituted by a bank of batteries, and a casing 34 which contains all the components of Fig 2A, although obviously the radar component of the speed of measuring device 16 can be separate for more convenient location.

The audio alarm general circuit 24 is provided with a separate energy source 38 (again a bank of batteries) and the code from code generator 29 is continuously transmitted, being demodulated by demodulator 39 and fed into Mr ~II the watchdog 33. In the event that the code ceases to be transmitted, the alarm indicato either becomes illuminated or emits a squealing sound, and it also operates if voltage of the batteries of energy source 38 become low, there being a battery low sense device 41 (volt sense type device) so that the work gang at the site 10 can be aware of the most likely causes of failure.

Assuming that an overspeed signal is received from a vehicle, and that signal is transmitted to the receiver 28, and demodulated by demodulator 39, the signal is fed as a voltage signal through the buffer 44 to an alarm control circuit 45 which activates the audible alarm 25. The voltage can be identified as a function of overspeed, and therefore either the pitch or the volume of the audio alarm 25 can be made to vary in accordance with the over speed of the vehicle. It is of course necessary that this should itself be controllable and such control is achieved through the siren pitch and delay control device 47, but can cause the audible alarm to continue to sound after the vehicle has 15 passed the speed measuring device. In addition to activating the audible alarm the alarm control circuit 45 can also activate the flashing lamp 48.

The "fail safe" operation of the circuit elements 33, 40 and 41 can also be used to check voltage propagation of the signal (for example the range) and since the range is essentially short, it can check that the range is not exceeded.

20 It will also check that the signal is being properly transmitted and received by the relevant antenna (not herein shown).

Fig 3 illustrates a simple arrangement of the flashing lamp and display sign 21. The energy source 17 is utilised to operate a small motor 51 which most desirably is of the type used for windscreen wipers. That motor is energised through its coil shown diagrammatically as 52 upon closure of switch 53, 53 being the contacts of the data switch It is a charecteristic of windscreen wiper motors that they are provided with a gearbox 50 and a non-continuous circular driven slip ring 55 or some Ii

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equivalent thereto. The slip ring 55 is normally not in contact with a brush 56 until the slip ring 55 commences rotation, and use is made of this already well established characteristic. It is known that electrical equivalents to this arrangement also exist, but these are equally adaptable for the purposes of this invention.

The driving shaft 57 of the motor 51 is provided with a gear 58 which meshes with the first pinion 59 of a train of pinions and either each pinion is coupled to a respective rotatable bar 60,but preferably each alternate pinion is coupled to a bar 60 and the other alternate pinions are idlers. The bar 60 in this instance has a yellow painted face 61, and two other faces 62 which are painted black, forming an equilateral triangle in cross-section. The gear 58 is driven at a much faster rate than the slip ring 55, and when the switch 53 is closed, the coil 52 is directly energised from the energy source 17. Almost immediately a lobe on a cam 64 disengages from its follower 65 enabling the switch 66 to close and energise in the relay coil 67 which inturn closes the parallel switch contacts 68 and retains the relay 67 energised during the entire cycle until both the electrical conductivity path between slip ring 55 and brush 56, and the switch 66 are open at the end of the cycle. The switch 53 closes only momentarily, during the passage of a vehicle past the beam from the radar measuring device 16, although that signal can be maintained for a short period by capacitor or other means.

The sign 71 comprises a yellow coloured panel which can be slipped into a channel support and replaced with other panels for other purposes, the sign having its message transmitted through "cut outs" 72. When the sign is backed by the yellow faces 61 of the bars 60, no noticeable signal is transmitted to the driver, but as the bars 60 rotate the black sides 62 throw up a colour variation which gives the appearance of a flashing sign.

,i:ii, Li YL-I~ I This flashing sign is complemented by a flasher control 73 which activates a flashing light 74, the latter two components being standard automotive components.

With the termination of a cycle (for example 15 seconds duration) all the contacts of switches 53, brush and slip ring 56, 55 and switch 66 are open, so that the relay coil 67 open circuits when the yellow faces 61 are behind the sign panel 71.

A consideration of the above embodiment will indicate the invention to be one of low cost and simplicity and signs can be readily replaced wherein 10 motorists receive a secondary advice of overspeed, and wherein workers at a work gang site are apprised of overspeed before a vehicle reaches the site.

Claims (13)

1. A traffic warning device comprising at least one source of electrical energy, a speed monitor circuit, an alarm general circuit, and an electrical link between said circuits, said speed monitor circuit comprising a said energy source, a speed measuring device, a speed trigger threshold control, a comparator and an electrically operated sign so interconnected that when a voltage emanating from the speed measuring device exceeds a threshold voltage, said speed monitor circuit activates said sign, said alarm general circuit also comprising a said energy source, an alarm control circuit and an audible alarm, said audible alarm being activated by said a!arm control circuit, itself being activated by said speed monitor circuit simultaneously with said sign.

2. A traffic warning device according to claim 1 wherein said threshold voltage is a voltage adjustable to effect said activation of the sign at S' different vehicle speeds.

3. A traffic warning device according to claim 1 or claim 2 wherein the (or each) speed monitor circuit further comprises a data switch which closes when a voltage emanating from the speed measuring device 20 exceeds said threshold voltage, and in closing completes a circuit to said sign from said energy source and thereby effects said activation of the sign.

4. A traffic warning device wherein there are two said speed 1 monitor circuits each according to claim 1 or claim 2, and one said alarm general circuit, each said electrical link being a separate radio frequency link between a said speed monitor circuit and said alarm general circuit.

A traffic warning device according to claim 4 wherein each said alarm circuit further comprises a code generator, modulator and radio i transmitter, and said alarm general circuit comprises a radio receiver having reception frequencies of said transmitters.

6. A traffic warning device according to claim 5 wherein said alarm general circuit further comprises a demodulator and buffer between said receiver and said alarm control unit, and a siren pitch and delay control coupled direct to said alarm control unit.

7. A traffic warning device according to claim 5 or claim 6 wherein said alarm general circuit further comprises a watchdog timer, a battery voltage sensor, and a unit-fail alarm/indicator coupled to said timer and 10 sensor to indicate failure of receipt of a code from said code generator or existence of low voltage.

8. A traffic warning device according to claim 3, or any S preceding claim when dependant on claim 3, wherein said electrically operated sign comprises a motor, a plurality of adjacent parallel multifaced bars, a gear on the motor and a plurality of inter-meshing pinions on respective said bars arranged to be driven simultaneously by said motor gear upon activation of S said motor consequent to closure of said data switch, and a sign panel having cut-outs located adjacent but forwardly of said bars, such that upon rotation of said bars, said sign is readable by contrast of colours of said sign panel and said faces of the bars.

9. A traffic warning device according to claim 8 further comprising a flasher control and a flashing light in the same circuit as said motor to activate the flashing light during operation of the motor.

A method of warning motorists and road workers of overspeed when on a road, comprising: detecting vehicle speed with a speed measuring device in a monitor circuit; I activating an over-speed warning sign if the speed exceeds a threshold vlue; transmitting data from said monitor circuit to an alarm general circuit at a location spaced from said monitor circuit, by a radio frequency link; and operating an audio alarm by an alarm control circuit at the location of said alarm general circuit.

11. A method of warning motorists and road workers of overspeed when on a road, according to clsim 10 wherein both said monitor circuit and said alarm general circuit are in accordance with any one of claims 1 to

12. A traffic warning device substantially as hereinbefore described with reference to and as illustrated in the accompanying representations.

13. A method of warning motorists and road workers of overspeed when on a road substantially as hereinbefore described with reference to and as illustrated in the accompanying representations. Dated this 7th day of July,1994. JEFFREY HERBERT SCHOLES By his Patent Attorney KEN MADDERN ABSTRACT Both motorists and road workers are warned of existence of hazard due to overspeed by detecting vehicle speed with a speed monitor (12) upstream from a work site, by activating an overspeed warning sign If the speed exceeds the threshold value, data from the monitor circuit (12) of an alarm circuit at the work site is transmitted by a radio frequency link and operates an audio alarm (25) simultaneously with the warning sign (21) so that workers at the work site are also alerted to the overspeeding of oncoming traffic. 9.i o *l r c r