WO1989011984A1

WO1989011984A1 - Wireless tow lighting system

Info

Publication number: WO1989011984A1
Application number: PCT/US1989/002287
Authority: WO
Inventors: William B. Anderson
Original assignee: Anderson William B
Priority date: 1988-05-31
Filing date: 1989-05-25
Publication date: 1989-12-14
Also published as: EP0382810A4; CA1318375C; EP0382810A1

Abstract

A temporary lighting system (10) for vehicles in tow comprises a pair of radio frequency controlled lighting assemblies (16, 18) that each include a rechargeable battery (46) as well as magnets (50) for coupling of the assembly to, for example, the trunk of a disabled vehicle (22). A transmitter (12) is mounted within a cab of the towing vehicle (14) and is electrically connected to the brake and turn signal circuitry of the towing vehicle (14) in order to transmit a coded wireless signal to each of the lighting assemblies (16, 18). A receiver (40) in each lighting assembly decodes the signal and illuminates a bulb (32) within the assembly in order to signal drivers behind the disabled vehicle (22) that the operator of the towing vehicle (14) is about to effect a turn or has applied the brakes. The bulb (32) of each lighting assembly also includes a filament which can be automatically or manually energized to serve as running lights.

Description

WIRELESS TOW LIGHTING SYSTEM

Background of the Invention

1. Field of the Invention

This invention relates to a temporary, radio controlled lighting system for disabled vehicles in tow and includes a pair of light assem¬ blies that are releasably mounted on the trailing end of the disabled vehicle and which are automati¬ cally illuminated upon energization of turn signals 10 or brake lights of the towing vehicle.

2. Description of the Prior Art

Tow trucks and other vehicles for towing disabled vehicles are normally equipped with flash¬ ing or beacon-type lights to provide a warning to -_jc other vehicles in the roadway. These types of lights are normally mounted above the cab of the tow truck for improving visibility to others. Such lights, however, do not normally duplicate the signals provided by the tail lights of the tow truck which indicate to the drivers of trailing vehicles 0 that the brakes of the tow truck are applied or that the driver of the tow truck intends to effect a turn.

Moreover, the towed vehicle often obscures the rear lights of the tow truck particularly in 5 instances where the towed vehicle is of substantial size. As such, it is preferable, and mandatory in some jurisdictions, to provide lights on the trail¬ ing end of the towed vehicle that are interconnected with the brake signal circuitry and turn signal 0 circuitry of the towing vehicle.

In the past, commercial tow truck opera¬ tors have provided auxiliary rear lights for the vehicle in tow by permanently wiring an auxiliary

5 -3- lighting assembly into the turn signal and brake signal circuits of the tow truck, utilizing among other components a section of flexible wire of a length sufficient to extend from the circuitry of the tow truck to the expected location of the auxiliary lighting which is mounted on the trailing end of the towed vehicle. Unfortunately, it has been found in practice that the length of wire often becomes tangled, torn and sometimes severed in use, especially when the tow truck is maneuvered around turns. As a result, the operator is then faced with the time and expense of replacing the wire in order to put the lighting system back into service.

Summary of the Invention In order to overcome the problems noted hereinabove, I have devised a tow lighting system that includes a radio transmitter carried by the tow truck and operatively connected to the light cir¬ cuitry of the tow truck, along with a pair of sepa¬ rate, self-contained lighting assemblies which each include a power source and receiver for receiving coded radio frequency signals. Both of the lighting assemblies include a magnetic base for detachably mounting the assemblies on, for instance, the top of the trunk of the towed vehicle, and one of the lighting assemblies is designated as "right" and the other designated as "left" in order to duplicate the function provided by left and right signal lamps respectively of the tow truck.

In accordance with a preferred embodiment of my invention, each of the lighting assemblies includes a bulb enclosure as well as an enlarged base which houses a number of magnets as well as a rechargeable battery for powering the bulb and the radio signal receiver that is located within the bulb enclosure. When not in use, the lighting assemblies are removed from the towed vehicle and placed within a recharging stand within the cab of the tow truck in order to retain the batteries at a fully charged state in readiness for the next use. Optionally, the recharging stand may also house the transmitter that is connected by a length of wire to a transmitting antenna mounted atop the roof of the tow truck cab. In other preferred forms of the invention, a bulb of each lighting assembly has two filaments, one of which functions as a turn signal or brake signal and the other of which provides steady illu¬ mination when desired to serve as a running light. Each lighting assembly includes a photo transistor to automatically energize the filament for the running light when the respective housing is exposed to darkness, and optionally a switch may be provided to manually turn the running light on or off.

These and other objects of my invention will become more apparent from a consideration of the following detailed description of a preferred embodiment of my invention, when the description is taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

Figure 1 is a perspective view of a tow truck that is towing a disabled vehicle, wherein is provided a wireless tow lighting system constructed in accordance with the principles of my invention; Fig. 2 is an enlarged, rear elevational view of one of two lighting assemblies of the system shown in Fig. 1, with a portion of a lens of the assembly cut away to reveal an internal bulb; Fig. 3 is an enlarged, side cross- sectional view of the lighting assembly shown in Fig. 2, showing among other things a battery and magnets which are received in a chamber of a base of the assembly;

Fig. 4 is essentially an electrical schematic diagram of a radio frequency transmitter of the system depicted in Fig. 1; and

Fig. 5 is essentially an electrical schematic diagram of a radio frequency receiver and signal lamp circuitry of the system illustrated in Fig. 1.

Detailed Description of the Drawings

Referring initially to Fig. 1, a wireless tow lighting system 10 includes, in broad terms, a transmitter 12 that is carried by a towing vehicle such as a tow truck 14, and a pair of signal re¬ ceiving light assemblies 16, 18 that are releasably mounted on a body 20 of a disabled vehicle 22. An antenna 24 is mounted on the roof of the .cab of the tow truck 14, and is interconnected by a wire (not shown) to the transmitter 14 which may optionally be carried behind the seat within the passenger com¬ partment.

Reference is now made to Figs. 2 and 3 wherein the lighting assembly 16 is shown in greater detail, although it is to be understood in this regard that the light assembly 18 is substantially similar to the assembly 16 with the specific excep¬ tions enumerated below. The assembly 16 includes a housing, broadly designated 26, that comprises a somewhat rectangular base 28 and an enclosure 30 coupled to the top of base 28. A dual filament bulb 32 (Fig. 2) is mounted within the enclosure 30 and is covered by a translucent lens 34 of a reddish tint. A photo transistor 36 is mounted at the top of a peripheral, cylindrical wall of the enclosure 30, and a three position slide switch 38 is carried on the side of the enclosure 30 with a finger engaging lever of the switch 38 protruding through a complemental slot in the wall of enclosure 30. A radio frequency signal receiver 40, the position of which is indicated generally in Fig. 2, is mounted within the enclosure 30 and is operatively coupled to a flexible, up¬ standing antenna 42 that protrudes through the top of the enclosure 30.

The base 28 of the housing 26 has struc- ture defining an internal chamber 44 (Fig. 3) that receives a source of power such as a rechargeable six volt battery 46. In addition, the chamber 44 carries a pair of elongated', parallel, magnetic mounting assembles 48 disposed on opposite sides of the battery 46, and each assembly 48 includes a central magnet 50 engaged on opposite sides by metallic plates 52 that extend through slots formed in the bottom of base 28. Each plate 52 is ver¬ tically shiftable to a limited extent in order to come into firm contact with the contour of a selected portion of the vehicle body 20.

A jack 54 extending through a sidewall of base 28 is provided for recharging the battery 46 whenever the lighting assembly 16 is not in use. Conveniently, the transmitter 12 within the cab of tow truck 14 is housed in a recharging stand that has a reception area for each of the lighting assemblies 16, 18 along with appropriate leads having plugs for connection with each recharging jack 54 when the assemblies 16, 18 are not in ser¬ vice .

In addition, the base 28 is marked with external indicia 56 in the nature of a "R" or the term "right" to indicate to the operator that the assembly 16 is to be placed on the driver's right side of the trailing end of the disabled vehicle 22. Likewise, although not shown in detail, the lighting assembly 18 has a housing 26a (Fig. 1) with external indicia in the nature of a "L" or the term "left" to indicate to the operator that the assembly 18 should be placed on the side of the disabled vehicle 22 that corresponds to the. driver's left side.

The transmitter 12 of the system 10 is shown in detailed schematic form in Fig. 4 and includes three terminals designated Jl, J2 and J3 that are connected, respectively, to wires of the tow truck 14 that are energized upon application of the right turn signal, left turn signal and brakes. The terminal Jl is connected to a current limiting resistor Rl (770 ohms), the other side of which is coupled to pin 1 of a tranεiεtor-transistor-logic (TTL) integrated circuit 57 (74HC266) as well as the cathode of a zener diode CRl (IN749A), the other side of the latter of which is connected to ground. Terminal J2 is connected by a resistor R2 (770 ohm) to pin 5 of the TTL circuit 57, as well as to the cathode of zener diode CR2 (IN749A) that has an anode coupled to ground. Terminal J3 is intercon¬ nected by a resistor R3 (770 ohm) to pins 2 and 6 of the TTL circuit 57, as well as the cathode of a zener diode CR3 (IN749A), the anode of which is grounded. The TTL circuit 57 is powered by the power supply of the towing vehicle or tow truck 14 and includes two exclusive NOR gates. From the 12 volt supply of the tow truck 14, current flows through a manual switch Si to a resistor R4 (14.7 ohms) that is connected by a lead 58 to pin 14 of the TTL circuit 57. The cathode of a zener diode CR4 (IN963B) is connected to lead 58, while the anode of CR4 is grounded. Capacitors Cl (100 microfarad) , C2 (10 microfarad) and C3 (0.1 microfarad) are also interconnected between lead 58 and ground along with a zener diode CR5 (IN749A), the anode of which is connected to ground.

Pins 3 and 8. of the TTL logic circuit 57 are electrically coupled to pins 5 and 6 respec- tively of a radio frequency encoder/transmitter Ul (LM1871). In addition, the lead interconnecting pin 3 of the TTL logic circuit 57 and pin 5 of Ul is connected to the cathode of- a zener diode CR6 (IN747A), the anode of which is grounded. The lead interconnecting pin 4 of the TTL circuit 57 and pin 6 of Ul is connected to the cathode of zener diode CR7 (IN747A) which also has an anode connected to ground.

The encoder/transmitter Ul receives power through pin 14 which is connected to lead 58, the latter of which is coupled to a capacitor C4 (0.1 microfarads) which is coupled on its opposite side to ground. In addition, pin 9 of Ul is connected to ground. Pins 1, 2, 3, 16, 17 and 18 of Ul are connected to a resistor R5 (82K ohm), the other side of which is connected to pin 8 of Ul as well as one side of another resistor R6 ( 56K ohms). The remaining side of resistor R6 is electrically coupled to pin 15 of Ul. Pin 7 of Ul is connected by a capacitor C5 (0.1 microfarad) to ground, and also is coupled to one side of a resistor R7 (200K ohm) , the other side of which is connected to lead 60. Lead 60, in turn, is connected to pin 4 of Ul as well as a capacitor C6 (0.1 microfarad), the other side of which is grounded. A capacitor C7 (0.005 microfarad) interconnects pin 8 of Ul and

"' ground, while a capacitor C8 (62 picofarad) inter¬ connects pin 10 of Ul and ground. Moreover, resis¬ tor R8 (47K ohm) interconnects pin 10 of Ul and lead 60. One side of a capacitor C9 (0.01 microfarad) is connected to pin 12 of Ul, while the other side of

10 C9 is coupled to ground.

One side of a crystal YI (49.86 Hz) is coupled to pin 10 of Ul, while the other side of Yl is electrically interconnected with one side of capacitor CIO (47 picofarad) as well as one side of

15 capacitor Cll (220 picofarad). The remaining side of CIO is connected to pin 11 of Ul, while the remaining side of Cll is coupled to a lead 62 that is directly connected to pin 13 of Ul. Lead 62 is also connected to a capacitor C12 (1500 picofarad) and a capacitor C13 (27 picofarad), and the other

20 side of capacitors C12 and CIS—is grounded. Lead 62 is also coupled to one side of the primary winding of transformer Ll (Toko KEN K4635 BJE), while the other side of the primary winding of Ll is coupled to pin, 11 of Ul.

25 Opposite sides of the secondary winding of Ll are coupled to respective, opposite sides of a capacitor C14 (33 picofarad), one side of which is also connected to one end of a tuning coil L2 (Miller #9330-10). The remaining side of L2 is

30 connected to the antenna 24 (see also Fig. 1) which is mounted on the top of the cab above the tow truck 14. The antenna 24 is advantageously one to two

35 feet in length and constructed of 0.023 inch diameter flexible wire.

An electrical schematic for the receiver 40 is illustrated in Fig. 5 and is substantially identical to the receiver of assembly 18. The re- ceiver 40 includes a radio control receiver/decoder U2 (LM1872) that receives power from the 6 volt re¬ chargeable battery 46 that is shown in Fig. 3. An on-off switch S2 interconnects pin 6 of U2 and the six volt battery 46 in order to disable the receiver 40 when not in service.

One side of a capacitor C16 (0.01 micro¬ farad) is coupled to pin 6 of U2 , while the other side of capacitor C16 is connected to ground. Pin 18 of U2 is connected to pin 2 of a mixer trans- former T2 (455 kHz; Tύko 10 EZC type RMC-202313 NO). Resistor RlO (200 ohm) interconnects pin 3 of T2 and one side of switch S2 adjacent pin 6 of U2, and pin 3 of T2 is also coupled to one side of a capacitor C17 (0.01 microfarad), the other side of which is grounded.

Pin 17 of receiver/decoder U2 is coupled to pin 4 of T2 and also to one side of a capacitor C18 (0.001 microfarad). The remaining side of capacitor C18 is connected to pin 6 of T2 and also to ground. Pin 16 of U2 is coupled to ground by means of a capacitor C19 (0.1 microfarad).

An intermediate frequency transformer T3 (455 kHz Toko 10 EZC type RMC402503 NO) includes pin 2 which is coupled to pin 15 of U2. Pin 3 of T3 is connected to one side of a capacitor C20 (0.01 microfarad), the remaining side of which is coupled to ground. A resistor Rll (100K ohm) interconnects pin 13 of U2 and one side of the switch Ξ2 as shown in the drawing. Pin 13 of U2 is also coupled to one side of a capacitor C21 (0.05 microfarad) the oppo¬ site side of which is grounded. As shown, pins 8, 10 and 14 of U2 are directly connected to ground.

A lead 66 is electrically coupled to one side of switch S2 as well as to one side of a capa¬ citor C22 (0.01 microfarad), the other side of which is grounded. A capacitor C23 (24 picofarad) inter- connects lead 66 and pin 1 of U2. A LO coil L3 (Toko 10K type KEN-4028 DZ 6T) is connected on one side to lead 66 and on an opposite side to pin 1 of U2 as well as one side of a parallel-mode crystal Y2 (49.86 mHz), the other side of which is directly coupled to pin 2 of U2.

Pin 3 of the receiver/decoder U2 is directly connected to ground as well as one side of a capacitor C24 (0.1 microfarad). The remaining side of capacitor C24 is connected to pin 4 of U2 as well as to one terminal of an antenna input trans¬ former T4 (Toko 10K type KEN-4028 DZ) . Opposite sides of another winding of T4 are connected to opposed leads of a capacitor C25 (24 picofarad), and one side of the capacitor C25 is also interconnected with antenna 42 (see. also Figs. 2 and 3) which may advantageously be in the form of a whip antenna of one to two feet in length.

One lead of the transformer T4 is also connected to pin 5 of U2 which is in electrical communication with the cathode of diode Dl (IN4454). The anode of diode Dl is also connected to the aforementioned lead of transformer T4 that is coupled to pin 4 of U2. Pins 7 and 9 of the decoder/receiver U2 are connected to corresponding poles of a single pole double throw switch S3. The remaining, common contact of switch S3 is connected to the base of a PNP transistor Ql (2N4920) , the emitter of which is powered by means of a lead in electrical communi¬ cation with one side of switch Ξ2. The collector of transistor Ql is connected to one side of a filament 68 within bulb 32 (see also Fig. 2) while the remaining side of filament 68 is coupled to a grounded, conductive case of bulb 32.

A second filament 70 within bulb 32 is grounded on one side by means of the aforementioned metallic case, and the other side of filament 70 is coupled to one side of a single pole single throw switch S4, the other side of which is coupled to the six volt battery 46 through switch S2. In addition, the latter-mentioned side of filament 70 is con¬ nected to one side of a normally on photo transistor 36 (see also Figs. 2 and 3), and the remaining side of photo transistor 36 is connected to the recharge¬ able battery 46 through switch S2. The photo tran¬ sistor 36 switches off in the presence of light.

Operation

Once the disabled vehicle 22 has been connected to the tow truck 14 for towing, the light¬ ing assemblies 16, 18 are removed from the recharg¬ ing stand that also houses transmitter 12 once the recharging leads (not shown) of the stand have been disconnected from the jacks 54. The lighting assem- blies 16, 18 are then placed on the trailing end of the disabled vehicle 22, such as the top of a trunk of vehicle 22, and positioned such that the lighting assembly 16 is disposed to the driver's right side while the lighting assembly 18 is positioned to the driver's left side. The magnets 50 shift within the base 28 as may be necessary to accommodate the surface contours of the body 20 of disabled vehicle 22.

Next, switch Si of the transmitter 12 is turned on to provide power to the TTL circuit 57 as well as the encoder/transmitter Ul. In addition, switch S2 of each of the lighting assemblies 16, 18 is turned on to power the receiver/decoder U2 as well as remaining components of the receiver 40.

If the system 10 is used at night and the housing 26 of each assembly 16, 18 is thus exposed to darkness, the photo transistor 36 enables current to flow to the filament 70 to serve as running lights. In this mode of operation, the photo tran¬ sistor 36 interrupts the flow of current to the filament 70 whenever sufficient light is detected. As an option, the operator may close switch S4 to manually illuminate filament 70.

In this regard, switches S2 and S4 of the receiver 40 may be incorporated into a single, three position switch such as the switch 38 that is depicted in Figs. 2 and 3. In this manner, the central position of the switch 38 may be designated as "off" for disabling power to all remaining com¬ ponents of the receiver 40. In accordance with this preferred construction, switch 38 when shifted to one side is equivalent to closing of both switches S2 and S4 (and thus constant energization of fila- ment 70), while shifting of the switch 38 to the opposite extreme is equivalent to closing of only switch S2 while leaving S4 open, so that automatic - #3- energization of the filament 70 is instead provided by means of photo transistor 36.

Viewing Fig. 4, each exclusive NOR gate of the TTL circuit 57 is connected to the brake signal circuitry of the tow truck 14, as well as to one of the turn signal circuits of the tow truck 14. Terminals Jl , J2 and J3 along with TTL circuit 57 thus represent a means for sensing activation of the turn signal circuitry or brake signal circuitry of tow truck 14. The output of each NOR gate is low when one and only one input of the same gate is high. Thus, if the brake signal and a turn signal of the tow truck 14 are energized simultaneously, the output of the NOR gate toggles back and forth between a low and high state. The encoder/transmitter Ul creates a pulse modulated FM signal at 49.86 mHz for every low output received on pins 5 and 6 of Ul . In the particular embodiment described above, four pulses are transmitted for a right turn, five pulses are transmitted for a left turn and six pulses are transmitted during application of the brakes.

The receiver 40 receives from antenna 42 the 49.86 pulsed mHz signal and mixes the signal down to an intermediate frequency of 455 kHz and thereafter outputs a decoded signal relative to its input. The receiver/decoder U2 thus represents a means for receiving a wireless signal transmitted from Ul and in response thereto for providing an output signal indicative of the activation of the turn signal circuitry or the brake signal circuitry of tow truck 14.

Pins 7 and 9 of the receiver/decoder U2 represent signal outputs suitable for the left

lighting assembly 18 and the right lighting assembly 16 respectively, the selection of which is deter¬ mined by the position of S3. Alternatively, switch S3- may be eliminated and the gate of transistor Ql connected directly to pin 7 of U2 for the receiver 40 of the lighting assembly 16 with pin 9 of U2 disconnected, while pin 9 of U2 is coupled to the gate of Ql for the receiver of lighting assembly 18 while pin 7 of U2 is disconnected. In this manner, the indicia 56 serve to indicate the position of the assemblies 16, 18 on the disabled vehicle 22 so that the operator need not manually adjust a position selector switch such as switch S3.

While the foregoing represents a detailed description of the currently preferred embodiment of my invention, it is understood that those skilled in the art may make various modifications or additions to my invention without departing from the gist and essence of my contribution to the art. Accordingly, the invention should be deemed limited only be a fair scope of the claims which follow along with their mechanical equivalents. What I claim is:

Claims

-/s_Claims :

1. For use with a towing vehicle having turn signal circuitry and brake signal circuitry and a towed vehicle having a body and connected to said towing vehicle, a lighting system comprising: means for sensing activation of said turn signal circuitry and activation of said brake signal circuitry of said towing vehicle ; means carried by said towing vehicle and con¬ nected with said sensing means for trans¬ mitting a wireless signal in response to activation of said turn signal circuitry or said brake signal circuitry; and a lighting assembly including a housing and means for releasably coupling said housing to said body of said towed vehicle, said lighting assembly -including means for receiving said wireless signal and in response thereto for providing . an output signal indicative of activation of said turn signal circuitry or said brake signal circuitry, said lighting assembly including illumination means and means electrically intercon¬ necting said illumination means to said receiving means for activation of said illumination means upon reception of said output signal.

2. The invention as set forth in Claim

1, wherein said means for releasably coupling said housing to said body of said towed vehicle includes a magnet.

3. The invention as set forth in Claim

2, wherein said housing includes a base carrying said magnet, and wherein said illumination means includes a bulb and an enclosure surrounding said bulb, said enclosure being coupled to said base at a location remote from said magnet.

4. The invention as set forth in Claim

3, wherein said base includes structure defining an internal battery-receiving chamber.

5. The invention as set forth in Claim 1, wherein said lighting assembly further includes a source of light distinct from said illumination means to serve as a running light.

6. The invention as set forth in Claim 5; and including means connected with said source of light for automatically energizing said source of light when said lighting assembly is exposed to darkness.

7. The invention as set forth in Claim 1, wherein said wireless signal comprises a radio frequency signal.

8. For use with a towing vehicle having right turn signal circuitry, left turn signal cir¬ cuitry and brake signal circuitry, and a towed vehicle having a body and connected to said towing vehicle, a lighting system comprising: means carried by said towing vehicle for sensing activation of said right turn signal circuitry, for sensing activation of said left turn signal circuitry and for sensing activation of said brake signal circuitry; means carried by said towing vehicle and con¬ nected with said sensing means for trans¬ mitting a first wireless signal in re¬ sponse to activation of said right turn signal circuitry, for transmitting a second wireless signal in response to activation of said left turn signal cir¬ cuitry, and for transmitting a third wireless signal in response to activation of said brake signal circuitry; and a lighting assembly carried by said towed vehicle and including right illumination means and left illumination means, said lighting assembly including means for receiving said first signal, said second signal and said third signal and for energizing said right illumination means in response to reception of said first signal, for energizing said left illu¬ mination means in response to reception of said second signal, and for energizing both of said right illumination means and said left illumination means in response to reception of said third signal.

9. The invention as set forth in Claim

8, wherein said lighting assembly includes a first housing carrying said right illumination means and includes a second housing separate from said first housing and carrying said left illumination means.

10. The invention as set forth in Claim

9, wherein said lighting assembly includes a first magnet connected to said first housing and a second magnet connected to said second housing for releas- ably securing said first housing and said second housing respectively to said body of said towed vehicle.

11. The invention as set forth in Claim 9; wherein said lighting assembly includes a first source of light carried by said first housing and distinct from said right illumination means, and wherein said lighting assembly includes a second source of light carried by said second housing and distinct from said left illumination means, said first source of light and said second source of light serving as running lights.

12. The invention as set forth in Claim 11; and including means for automatically energizing said first source of light whenever said first housing is exposed to darkness.

-I -

13. The invention as set forth in Claim 9, wherein said lighting assembly includes a first source of power carried by said first housing for energizing said right illumination means, and where¬ in said lighting assembly includes a second source of power separate from said first source of power and carried by said second housing for energizing said left illumination means.