Field of Invention

This invention relates to the field of automotive lights, and in particular wireless tail lights for trailers.

Background

When using a boat trailer or utility trailer or recreational vehicle, you are required to have legal rear tail lights for turn signals and brakes. Hand signals can be used as a last resort, but running lights are also required at night. Unfortunately, wired lights on trailers are often only used occasionally, and wires mounted externally on trailers or underneath vehicles require maintenance and can easily get broken out in the weather. If they stop working, there is no indication to the driver. Even checking that they are working before a trip may require several walks from the vehicle to the back of a trailer as different lights are turned on.

If they are not working correctly, there could be a broken wire somewhere, the plug connecting the vehicle and trailer may be loose, there could be a worn-out bulb or corrosion in the light socket. Repairing lights that aren’t working or installing new aftermarket trailer lights may take 2-3 hours. The process is actually so inconvenient, time-consuming and error-prone that where road regulations require safety checks for vehicles and trailers, working trailer lights may not be part of the safety requirements.

The problem is even worse if you stop during a trip and notice the lights not working. It is wise to check trailer lights during each stop, since they are so unreliable. This is an archaic system. The trailer tires can also throw up stones from gravel roads or asphalt from road construction, easily damaging wires and connections underneath the trailer.

Although the legal requirements are for turn signal lights, brake lights and running lights, a fundamental problem is that trailers are made by a different company than the vehicle, and the trailer is often sold without lights. Aftermarket light kits are made by other companies. Depending on the type of trailer, there are also variety of connector plugs for the wiring.

The biggest problem is that even with a brand new trailer lights, they traditionally have only 2 wires on the left and 2 wires on the right, and a ground wire attached to the trailer. But in the rear of a vehicle there will be a multitude of wires on each side for red brake lights, orange turn signals and also running lights. On the vehicle there are separate lights for turn, brake and running lights, but on the trailer these may all be in a single light. So there may be no way to make a wire-to-wire connection between the vehicle and trailer and have the trailer lights work correctly.

Adapters exist that allow wiring of multiple tail lights on one side to the two sets of trailer light wires, but these are often expensive and hard to find, as well as time-consuming to install. For faster installation, a T-adapter may be available for a specific vehicle model, which plugs into a light socket and has the 4 trailer wires, doing the correct conversions internally. But that is an extra cost, and the adapters need to be available for many different models of vehicle, and to change every year, which is not realistic. Also, the vehicle manufacturer may leave an extremely tight space around the rear lights without space for adding a T-adapter. A simple solution is needed to avoid this problem of connecting large numbers of wires in the vehicle with a small number of wires in a trailer wiring kit, and figuring out which wires connect to which. Claims of “wireless trailer lights” have attempted to solve this problem, with a radio that is wired in to the rear lights in the vehicle. It then transmits to the trailer lights with no wires needed on the trailer.

However, that is only a partial solution. All of the difficulties attaching to the rear lights in the vehicle still remain. And worst of all, these “wireless trailer lights” usually require a power wire to be run under the vehicle to the engine compartment, and attached directly to the battery. That avoids damage a fuse or electronics in the vehicle when power is applied. But the requirement to run an electrical wire under the vehicle - past the gas tank and the hot exhaust and into the hot engine compartment - is inconvenient and usually requires raising the vehicle on a lift. So it defeats the very purpose of “wireless trailer lights”.

The existing methods and prior art have serious flaws, but they are used on all types of trailers including boat, camper and utility trailers, as well as recreational vehicles and 18-wheelers. The problems have existed for over 100 years, as long as vehicles and trailers have had electric lights. A device that could solve these problems would be very useful.

Foreground: Summary of the Invention

The invention disclosed here does not require attaching wires to the exterior of a trailer where they can easily be damaged, and is fast and convenient to install. Unlike so-called “wireless trailer lights” which do still require wiring into the vehicle, this new approach has no wires to connect in the vehicle. It bypasses the problem of connecting lots of wires to only 4 wires, since no wiring connections are used at all. It is not obvious how to achieve this goal, but we will show how in the description below.

We know there is not an obvious solution for this problem because there have been many attempts at “wireless trailer lights”, but removing wires from the trailer is only a small part of the problem. In the machine disclosed here, we use wireless tilt sensors to determine if the arm on the turn signal or brake pedal has been moved. This inventive step means that using the brakes or turn signals can turn on/off the trailer lights with no wiring added. The tilt sensor recognizes that the brake pedal or turn signal actuator has been moved, and radios a signal to the trailer lights to turn on the corresponding lights. This has never been possible before. It saves installation time and avoids the problem of trying to connect a multitude of wires in the vehicle to two pairs of wires for the trailer lights. Plus there are no wires that need to be installed under the vehicle, or attached to the exterior of a trailer where they can be damaged.

Using tilt sensors on switches could also be used for lights and other controls in a vehicle, where running wires is inconvenient. Or in buildings for the same reason. Why add weight and the time and cost to route many meters of wiring from a switch to a power source and to the vehicle’s own lights (or other electrical devices), if a radio signal can be sent? This may be especially beneficial on a large vehicle like a bus, recreational vehicle, aircraft or yacht. It may also be easiest and most cost-efficient to still use on-board power/ground wires at an effector like headlights or windshield wipers, but to activate them from the switch by radio transmission, to avoid running the wires to the switch. Batteries may be convenient for certain purposes like trailer lights, but power/ground wires may be available in the vehicle (or building).

This novel solution would be useful for boat trailers, utility and other types of trailers, and recreational vehicles. Although the radio tilt switch could be used in buildings, it is even more effective if it can detect movement in the actuator independent of the vehicle’s movement or tilt. This is a further inventive step, that is not obvious to someone skilled in the art: how to separate movement of the actuator from movement or tilt of the vehicle. Tilt sensors can be activated by centrifugal force when a vehicle goes around a comer. So we need to know if the whole vehicle is tilted or cornering, or just the turn signal or brake actuator. Fortunately, the turn signal’s axis of rotation is orthogonal to the brake pedal’s. It would be possible to put an additional tilt sensor on the vehicle, but that is unnecessary cost if we can detect motion in the turn signal and brake pedal together. If both of them move the same, we know it is movement of the vehicle. So an important inventive step here is to detect when there is independent movement by only one, and use that to turn on/off the corresponding light.

Movement of the turn signal arm and brake pedal can be detected with an electronic switch or sensor such as a potentiometer measuring resistance and transmitting by radio without limiting the scope of the invention disclosed here. But the simplest approach would be with a tilt sensor, which may be implemented with an Inertial Motion Unit comprised of a digital gyro and/or accelerometer.

If the sensor detects the vehicle moving in reverse, white reverse lights could automatically activated at the rear, to illuminate the area behind. However this is typically not necessary with trailer lights, which ordinarily do not have reverse lights.

Although the preferred embodiment is focused on solving problems with trailer wiring, the invention disclosed here solves similar problems for lights and switches on vehicles of all types. Running wiring through the vehicle is inconvenient and leads to hidden breakages. So whether on a car, truck, recreational vehicle, bus, motorcycle, bicycle, lawnmower, train, aircraft, or a yacht, if there was a way to detect a change in the tilt of the switch and to separate that from movement of the vehicle, that would be a new and useful solution. So the scope covers tilt sensors as a switch with wireless (radio) transmissions to avoid wiring. This is especially effective on a moving object since it can differentiate between movement of the object and of the switch.

Brief Description of the Figures

Figure 1 : Movements of turn signal arm and brake pedal arms that trigger tilt sensor.

Figure 2: Tilt sensor arms are held on turn signal and brake pedal with wiring clips or velcro wraps, with control box mounted under dashboard.

Figure 3: Location of wireless lights on trailer with radio and battery inside the lights.

Figure 4: Internal view of trailer light case and connections.

Detailed Description of the Preferred Embodiments

The description provided here is intended to allow a person skilled in the art to understand the parts of the machine, their functions and interactions, and the novelty of this solution. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics defined in the claims. The present embodiments are therefore to be considered as illustrative and not restrictive.

Although all previous trailer lights require wiring to the actuator switch, the inventive step described here is with a machine that provides its own power from batteries, does not need to connect to any wires in the vehicle, detects when the turn signals or brakes are activated, transmits this to trailer or tail lights, and does not require wires on the trailer.

Using tilt sensors to detect movement of the turn signals is not obvious, for two reasons. First, there is a long-standing tradition of electrical switches based on mechanical connections when the switch is physically moved. There has never been a tilt sensor used with turn signals or vehicle brakes or brake lights. Second, even if a tilt sensor was used, it would not be able to differentiate between tilt of the vehicle and tilt of the effector arm.

The growing accessibility of computing processors and wireless data has opened up a new solution to this problem. Once a user sees it working, it seems so simple and magical that they may say “Huh, why didn’t I think of that!”. But interestingly, this problem has been around for more than a century, and this solution is not obvious until after you see it working. Wireless technology is widely available in wifi, computers and smartphones now. But until the invention disclosed here, no-one skilled in the art has developed a way to remove the wiring, connectors and plug from the vehicle, and use wireless sensors on the brake pedal and turn signal to control trailer lights.

There could be a battery and transmitter electronics with each sensor, but in the preferred embodiment we use a central control box with one battery and radio, with two “arms” which are wires running onto the turn signal and brake pedal. The radio in the control box has a unique serial number, and is paired with the left and right trailer lights, which also have unique serial numbers. If the turn signal on the vehicle is raised, the tilt sensor detects this relative motion compared to the vehicle motion, and activates the correct turn signal on the trailer lights.

The circuit board, radio and batteries are self-contained inside the tail light housing. The trailer light housing does not need to be waterproof, because internally all wiring connections and electronics are potted in resin on a tray, and the batteries are in internal waterproof containers. This way, there is no need to attach a separate box on the back of the trailer for the batteries and radio.

In Vehicle:

To avoid connecting the wiring in the vehicle to a switchboard that interprets the lights turning on and sends this information to trailer wiring or a radio transmitter, our inventive step is to use tilt sensors in the vehicle to detect when the tilt sensor on blinker arm and brake pedal arm have been activated, transmitting commands by radio to the trailer lights.

As shown in Figure 1, the turn signal moves in one plane of rotation which is basically up and down, and the brakes move on another plane of rotation forward and back. If the brake pedal is depressed, the microprocessor with the tilt sensors differentiates this from vehicle movement, and a radio signal is sent to the trailer lights to turn on the brake lights. Similarly if the turn signal is raised or lowered independent of vehicle motion, a radio signal is sent to the left or right trailer light.

As shown in Figure 2, the machine disclosed here has a control box (1). It could be mounted in many locations in the vehicle such as inside the dashboard or on it, but in the preferred embodiment is mounted on the lower part of the dashboard below the steering wheel (2) and steering column. The control box could be permanently attached with double-sided foam tape, but in the preferred embodiment velcro on stickers allows it to be removable for storage or recharging. The control box contains a circuit board, a radio and a battery, with a display screen or light-emitting diodes for user feedback on battery levels, transmission signal strength, and whether the lights are all working. Two “arms” (3) extend out from the control box: wires with an encapsulated tilt sensor on the end (4). In the preferred embodiment, shrinkwrap is used as a cover on the tilt sensors at the end of the wires, but other types of cover could also be used. The wires are run to and along the turn signal arm (5) and brake pedal (6), and attached to each with clips with stickers on the back, or with velcro wraps (unless the wires are built in to each actuator). Unlike the usual in-vehicle installation time of 1 -2 hours, installing a few velcro stickers and velcro wraps would take seconds. By monitoring both tilt sensors, it is also possible to know if the vehicle is tilted, is experiencing G-forces while cornering or accelerating, or is moving in reverse (in case reverse lights need to be activated). We don’t want to turn on the trailer lights inadvertently simply because the vehicle is going around a comer or accelerating. These two planes are not the same. But even if they were not orthogonal, movement of the turn signal can be differentiated from the brake pedal. If the vehicle is on tilted ground or goes around a comer, the sensors on both planes will be activated. But an inventive step in the preferred embodiment is that a signal is only sent to a light if only the corresponding sensor has moved in its plane of rotation.

In the preferred embodiment, the user can calibrate the turn and brake sensors by moving them to indicate the plane of rotation. The firmware in the control box can wait to leam that for each sensor before it starts sending signals to the lights. The tilt sensor could respond to changes of position from the usual center point, although in the preferred embodiment the sensor activates a light based on acceleration of the effector. The light is only activated when one sensor detects a change in position or an acceleration; if both detect it, that is determined to be motion of the whole vehicle not the effector.

Low energy digital radio transmissions are used, which are 2.44 GHz in the preferred embodiment and similar to a garage door opener transmitting from inside the vehicle. Bluetooth Low Energy and other Internet of Things wireless transmissions would also be suitable. If the turn signal or brake pedal is moved, that sends a radio signal to the trailer lights to turn on the corresponding light.

There is a rechargeable battery in the control box. The control box can be opened if the battery needs to be replaced. A physical power switch on the control box allows it to be turned off when trailer lights are not needed, or when it is put in storage. Battery level (in both the control box and tail lights) can be displayed with rows of light-emitting diodes, or on a screen such as a liquid crystal display or organic light emitting diode display.

To ensure that the radio signal can be strong enough from inside the metal vehicle to get to the back of the trailer, signal strength is detected in the radio transceivers and displayed on light-emitting diodes or a display screen on the control box. This allows the user to choose a mounting location for the control box (and the tail lights) with sufficient signal strength.

Another inventive step is feedback confirming that the rear lights are (or are not) working. A display screen or light-emitting diode or dashboard display could indicate if the rear lights are/not being activated, but in the preferred embodiment audio feedback is provided such as a recurring beep. Then the driver does not need to go back and check the trailer lights at every stop, making the lights far more reliable than with the usual wiring connections.

The radio transceiver in the control box is paired to the left tail light and the right tail light. It knows which is which, and once paired does not communicate with other lights on nearby vehicles. In the preferred embodiment the transmissions are encrypted for security, to further ensure that a different controller or different lights are not inadvertently involved (or activated with malicious hacking). The same as a garage door opener is paired to only open one particular garage door, or a smartphone connects to only the paired wireless speakers.

In addition to turn signals and brake lights on the trailer, at night running lights/tail lights need to be turned on. Traditionally in trailer lights these are the same lights but used at about half of the brake light power. When the turn signal is applied, the brake or running light blinks. In the preferred embodiment, to save power we do not want to activate the night running lights all the time; only when needed at night. The running lights are off by default, but a signal can be sent from the transmitter unit in vehicle, to turn running lights on for driving at night. In the preferred embodiment a toggle switch on the control box turns on the night running lights. It would be possible to put the control box in sleep mode if the vehicle is not moving, and turn it fully on when vehicle motion is detected. However, in the preferred embodiment there is also a physical On/Off switch on the transmitter unit in the vehicle, to preserve the battery power during storage or when rear lights are not in use. This shuts off all power including to the brake and turn sensors, the radio and the microprocessor.

The control box and electronics in the vehicle are designed to use very low power, allowing long-lasting battery use. Because the control box is powered by battery, it does not need to attach to a vehicle power wire, so there is no chance of blowing a fuse or causing an electrical problem in the vehicle. A connector for DC power is used for recharging the battery in the control box. This could be round for an AC adapter but in preferred embodiment the connector is for a common smartphone cable such as a Universal Serial Bus (USB) or micro-USB connector.

On Trailer:

Figure 3 shows a typical trailer light arrangement, with left and right lights on the back of the trailer. In the preferred embodiment, the left and right lights are each self-contained with a radio transceiver and a rechargeable battery placed inside as shown in Figure 4. The radio transceivers in the left and right trailer lights are each paired with the radio in the control box in the vehicle. It would also be within the scope of this invention to place the battery and radio in an external waterproof box, but that requires extra mounting and wires on the trailer. The preferred embodiment is to have no wires to install on trailer, with self-contained lights.

Figure 4 shows the trailer lights case (1) that is attached to the left and right sides of the trailer. Bolts or bolt holes (2) are in the back of the case. The circuit board (3) is potted in resin in a tray to protect the electronics and wiring connectors. In the preferred embodiment the tail light case can be opened by removing screws holding on the red reflective lens (not shown in Figure 4), so that the battery or batteries can be replaced. Since water could get into the case, everything inside is waterproof and submersible. The battery or batteries (4) are in small waterproof canisters with screw-on caps (5). The light-emitting diode(s) (6) are potted in resin on a separate panel that is mounted behind or attached to the red reflective cover. Wires connect the lights and battery(s) to the circuit board and also to the DC charging outlet (7) and the On/Off switch (8). On the outside end of the left and right tail light cases, there is an additional side marker light (9). There may also be a clear panel on the bottom of the case (not shown in Figure 4) on one side for a license plate light. In the preferred embodiment two amber side reflectors are also supplied for the tongue of the trailer.

The battery can be replaced in later years if it wears out, opening the case by removing screws holding the red lens on. For convenient battery charging, in the preferred embodiment a hole is drilled in the case, with a waterproof charging plug inserted through the hole, with a nut threaded on to hold it in place. The charging plug gets closed with an attached waterproof cap. A standard Universal Serial Bus (USB) smartphone connector is used in the waterproof connector plug, since these are available internationally (unlike AC plugs, which vary in different countries). A USB plug is used in the preferred embodiment since it is sturdy, but a micro-USB plug such as on a smartphone could also be used. The user then recharges the battery by plugging an AC adapter into their local wall socket or extension cord, and connecting a USB cord from the AC adapter to the trailer light. Two USB cables can be used at once, one to the left trailer light and one to the right. In the preferred embodiment, the waterproof connector port is placed on the vertical wall of the trailer light, on the side facing across the back of the trailer to the other light. This is accessible, without encouraging water to collect around the socket. In the preferred embodiment the battery is plugged in, inside of the waterproof battery container within the trailer light. To ensure that the battery case is air-tight, an O-ring is used on the threads where the cap screws on. White grease is added to the threads to ensure that water cannot get in. Inside the battery case, a wire comes from the circuit board and has a small connector plug on the end. Caulking or sealant is used on the hole in the battery case where the wire enters. The battery is shrink-wrapped with wires soldered to metal tabs on each end of the battery, and a connector on the end of the wires, allowing the battery to be plugged in or removed from the waterproof battery case.

There is also a waterproof On/Off switch on left and right tail lights, to preserve battery power when not in use and when in storage. In the preferred embodiment, this switch is on the bottom or the side facing the other tail light (next to the waterproof recharging port), to resist gravity pulling water in.

For mounting the trailer lights, zip ties could be used temporarily for fast attachment with no tools. Another embodiment is that velcro straps could wrap around or stick on to the top and bottom of the tail lights, for quick attachment on back of trailer with no tools. Zip ties could optionally be added as a backup to the velcro. But in the preferred embodiment, two 1/4-inch bolts are attached to the back of the trailer lights, with the standard 2-inch center spacing for mounting to holes in the trailer.