Field of the invention

The invention relates to an electrical coupling system for electrical connecting a pulling vehicle to a trailer.

Background of the invention.

The current solutions for electrically connecting the electrical system of a trailer to the electrical system of a vehicle is not optimal. Both the socket and the plug is exposed to outdoor condition and gets corroded and dirt gets in between the pins and the pin receivers. Trying to force a dirty and corroded plug into a dirty and corroded socket can break or bend the pins of the plug. This makes it hard and eventually impossible to insert the plug into the socket.

One problem with the prior art solutions is that the plug and socket are too complex. To avoid the plug and socket to be too bulky the individual plugs and plug receivers need to be small, which again makes them fragile and the plug and the socket need to be perfectly aligned to be able to insert the plug into the socket.

The socket on a vehicle is often adapted to receive a trailer plug with in total 7 or 13 contact surfaces in the form of pins or pin receivers and the wiring from the vehicle to the trailer will often consist of 7 or 13 wires each with a single electrical conductor. Each conductor supplies power to a function, light or set of functions/lights on the trailer or is a grounding wire. For instance, one of the 7 or 13 conductors might be a conductor for the brake light on the trailer, so when the driver hits the brake the wire conducts a current which would be the signal to the brake light on the trailer, so it lights up. The current would be both the signal for turning on the brake light and supply the power for the brake light.

Some time back it was most common with 7 pins and pin receivers, but due to more functions and lights on the trailer it was at some point increased to 13 pins for most trailer plugs and sockets. So, in situations where an old trailer needs to be pulled by a new vehicle or the other way around an adapter is needed. The adaptor increases the complexity and the number of contact points that can be corroded, bent or damaged and lead to errors in operating the lights on the trailer. It is therefore a need for a system that mitigates these problems.

Disclosure of the state of art

CA2893682A1 describes a series of devices for storing, protecting, and securing various common types of terminal end connectors of a trailer light or combined trailer light and braking system wiring harness including an electrically non-conductive - plug receiving -base having a female receptacle therein, or combination of female receptacle therein and a laterally adjacent, elongated male dummy plug for receiving complementary formed, electrically conductive, male and female electrical terminals, respectively, provided in the terminal end connector. A mechanism is provided for mounting the electrically non-conductive - plug receiving - base on a trailer structure or vehicle adjacent to the terminal end connector in order to secure and protect the various terminal end connectors of a trailer light or combined trailer light and braking system wiring harness.

Objects of the present invention

An object of the invention is to provide a system more reliable than the prior arts systems for connecting the electrical system of a vehicle to the electrical system of a trailer.

An object of the invention is to provide a user-friendly system for connecting the electrical system of a vehicle to the electrical system of a trailer.

An objective of the invention is to provide a plug and a socket for connecting the electrical system of a vehicle to the electrical system of a trailer that is more reliable compare to the prior art systems.

An objective of the invention is to provide a plug and a socket for connecting the electrical system of a vehicle to the electrical system of a trailer that is more user friendly than the prior art systems.

An objective of the invention is to provide an alternative to the prior art systems. An objective of the invention is to provide a system that is an improvement over or an alternative to the prior art systems for connecting an electrical system of a vehicle and a trailer, and that the system is easy to adopt, i.e. install on an existing vehicle and/or trailer.

An objective of the invention is to provide an electrical system for connecting a vehicle to a trailer that is not limited or less limited than prior art system when it comes to the number of electrical consumers on the trailer that can be controlled by the vehicle or give feedback to the vehicle.

Summary of the invention

The invention relates in one aspect to an electrical coupling system for electrical connecting a pulling vehicle to a trailer. The electrical coupling system comprises: a vehicle signal converter, arranged to convert signals between electrical signals in a vehicle multi conductor system and at least one control signal, the control signal comprises power from the pulling vehicle, a trailer signal converter arranged to convert signals between electrical signals in a trailer multi conductor system and at least one control signal, the control signal comprises power to the trailer, a socket, operatively coupled with one of the of the signal converters, a plug operatively coupled with the other of the signal converters, and means for transferring the at least one control signal and power between the signal converters, via the socket and the plug when the plug is connected to the socket.

Each of the signal converters can further comprises a SerDes module.

The vehicle signal converter can be comprised inside a socket housing or a plug housing.

The trailer signal converter can be comprised inside a socket housing or a plug housing. The vehicle signal converter can be comprised inside an adapter adapted to adapt the socket or the plug to fit with an existing socket or an existing plug connected directly to the vehicle multi conductor system or the trailer multi conductor system.

The means for transferring a control signal and power between the signal converters can be a signal conductor.

The socket can comprise a contact surface for conducting a control signal and power to a mating contact surface on the plug.

The first socket contact surface and the mating first plug contact surface can be circular.

The control signal and power can be transferred between the socket and the plug by means of an inductive coupling.

The electrical coupling system can be a replacement kit for replacing existing systems on vehicles and trailers.

Description of the diagrams

Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:

Fig. 1 shows in principle an embodiment of the invention.

Fig. 2 shows detailed view of the embodiment according to Fig. 1.

Fig. 3 shows in principle one embodiment of a plug and a socket that can be used with an electrical system for coupling a towing vehicle to a trailer.

Fig. 4 shows in principle a possible embodiment of the invention where the signal converters are comprised inside the plug and the socket. Description of preferred embodiments of the invention

The invention relates to a trailer coupling system i.e. an electrical system for coupling a towing vehicle 1 such as a car or truck to a trailer 2. Such a connector or coupling systems intended primarily to supply automotive lighting on the trailer 2, but also provide management and supply to other electrical consumers 5. The connector can also supply feedback from the trailer 2 to the towing vehicle 1. Electrical coupling systems with the similar purpose is in the prior art often referred to as trailer wire, trailer cable or trailer connecting cable. In the following we will use the term electrical coupling system 10 in relation to embodiments of the invention.

The electrical coupling system 10 according to an embodiment of the invention comprises a vehicle signal converter 20, a trailer signal converter 30, a socket 40, a plug 50 and means 60 for transferring at least one control signal and power between the signal converters 20,30 via the socket 40 and the plug 50.

The vehicle signal converter 20 interfaces with a vehicle multi conductor system 3 in a vehicle 1. The vehicle multiconductor system 3 would normally in the prior art be terminated in a socket for plugging in a standard plug of a trailer 2. Instead of terminating the vehicle multi conductor system 3 in a socket it is in this embodiment of the invention connects to the vehicle signal converter 20. The vehicle signal converter 20 converts the signals from the vehicle multi conductor system 3 into at least one control signal that is sent to the trailer signal converter 30 together with power.

The means 60 for transferring the control signal and power can be a single signal conductor 60 ^' . The signal conductor 60 ^' can be connected to the socked 40 that can be mounted at the rear of the vehicle 1. The socket 40 is adapted to receive the plug 50 that is connected to the trailer 2. The socket 40 and the plug 50 are each equipped with two contact surfaces, preferably two concentrically disposed annular contact surfaces. A first socket contact surface 42, and a first plug contact surface 52 is for transmitting power and control signals between the socket 40 and the plug 50 when the plug 50 is inserted into the socket 40. A second socket contact surface 43 and a second plug contact surface 53 is used for current return or grounding when the plug 50 is inserted to the socket 40.

The signal conductor 60 ^' is in a first end 61 terminated in the vehicle signal converter 20. The signal conductor 60 ^' stretches to the trailer signal converter 30 via the first socket contact surface 42 and the first plug contact surface 52. The second end 62 of the signal conductor 60 ^' is terminated in the trailer signal converter 30.

The trailer signal converter 30 is connected to a trailer multi conductor system 4. The trailer signal converter 30 converts the control signal from the signal conductor 60 ^' into a plurality of electrical signals for the trailer multi conductor system 4.

It is important to note that the trailer signal converter 30 also can convert electrical signals from the trailer multiconductor system 4 into at least one control signal on the signal conductor 60 ^' , and that the vehicle signal converter 20 can convert this control signal from the signal conductor 60 ^' into electrical signals for the vehicle multiconductor system 3.

An technical effect of the signal converters 20, 30 is that the electrical signals (power on/off for instance) from the multi conductor system 3, 4 can be coded into a lower number of signals compare to the number of electrical signals in the multi conductor system 3, 4. Which again can be sent via a lower number of conductors compare to the multi conductor system 3, 4. So for instance the electrical signals from the 7 or 13 (or any other number of conductors) conductor multi conductor systems 3,4 can be coded into signals on for instance one single signal conductor 60 ^' .

With reference to Fig. 3 an embodiment of the socket 40 and the mating plug 50 will be described. This embodiment of the plug 50 and socket 40 can be used as part of the previously described electrical coupling system 10.

The socket 40 comprises a guide hole 41 a first socket contact surface 42, a second socket contact surface 43 and a socket housing 44. The guide hole 41 is for accommodating a mating guide key 51 on the plug 50. The first socket contact surface 42 is for transmitting an electrical signal and power from the first part 63 of the signal conductor 60 to the second part 64 of the signal conductor 60. A mating first plug contact surface 52 is accommodated on the plug 50. The second socket contact surface 43 is for grounding the trailer multi conductor system 4. A mating second plug contact surface 53 is accommodated on the plug 50. The plug 50 comprises the guide key 51 for guiding and locking the plug 50 to the socket 40. The plug 50 further comprises the first plug contact surface 52 and the second plug contact surface 53 and a plug housing 54. To secure the plug 50 to the socket the guiding key can be equipped with a peg protruding radially out from the guide key 51 as seen in fig. 3. When the guide key 51 is inserted into the corresponding guide hole 41 in the socket 40 the plug 50 can be turned so that the peg prevents the guide key 51 from exiting the guide hole 41. The peg will when the plug is turned slide on an inclined (with an inclined angle relative to the plane of the contact surfaces 42, 43) surface on the inside of the socket (not showed in the Fig). So, when the plug 50 is turned it is also pulled towards the socket 40. This will improve the electrical connection by pressing the conductive surfaces (42, 43, 52, 53) of the plug 50 and the socket 40 together and will improve the seal of any gaskets that can be included on the plug and/or socket.

All though the common setup is that the socket 40 is on the vehicle 1 and the plug 50 is on the trailer 2 it can be opposite. If so the trailer signal converter 30 would be wired to the socket 40 and the vehicle signal converter 20 would be wired to the plug 50.

Coding, decoding and sending a control signal between the signal converters 20, 30 can be done by modulating i.e. vary an amplitude, frequency or intensity of a carrier wave which is a well-known technique in telecommunication. Such modulating or any other technique well known to the person skilled in the art can be used to transmit the control signal.

One technology that can be used and is available of the shelf is SerDes modules.

The signal can be encoded in the form of Manchester coding which is a well-known technique for the person skilled in the art.

The vehicle signal converter 20 can be comprised inside the socket housing 44 and the trailer signal converter 30 can be comprised inside the plug housing 54. The signal converters 20,30 can also be placed at other locations on the trailer or on the vehicle. Such as placing the vehicle signal converter in the trunk of the vehicle and the trailer signal converter inside a beam in the frame of the trailer 2.

To ease the adaption of the invention in cases where the invention is mounted as an upgrade or a replacement of a prior art system on a vehicle, one of the signal converters 20, 30 is comprised inside an adapter to be placed between a socket and a plug. This is an advantage because it might be needed to pull trailers 2 that has a prior art system with a plug or socket with for instance 7 or 13 contacts surfaces such as pins and/or pin receivers. It might also be the case that a trailer 2 upgraded in accordance with an embodiment of the invention needs to be pulled by a vehicle with a prior art system comprising a socket or a plug with for instance 7 or 13 contact surfaces (pins and pin receivers).

In an alternative embodiment the socket 40 and the plug 50 are inductively coupled. Typically, an inductor such as a coil is embedded in the mutually mating contact surfaces on the socket 40 and plug 50. This allows for a coating layer that also ensures no moisture ingress into the electrical parts and thus no corrosion. In a preferred embodiment the inductors are coils that align coaxially, thus allowing for mating at any rotational angle and thus makes keying superfluous.

A grounding connection between the vehicle and trailer is nevertheless preferred, which can take place through the socket 40 and the plug 50. In use, the vehicle signal converter 20, possibly using a SerDes module 80, generates a pulse train of signals transmitted to the first end 61 of the signal conductor 60 ^' that is operatively connected to the socket 40. The pulse train allows for inductive coupling of signal as well as power, to the plug 50. Use of coding schemes such as Manchester encoding ensures a continuous pulse train without long dwell times with current on or current off. The pulse train along with induced electrical power is then transmitted from the plug 50 over the second part 64 of the signal conductor 60 ^' , to the trailer signal converter 30. Thus, the signals and electrical power from the vehicle multi conductor system 3 is transferred to the trailer multi connector system 4 for use in electrical consumers 5 on the trailer 2.

One possible way of adopting the electrical coupling system 10 is as a replacement of existing prior art systems on vehicles that is already in use. In such cases the system can be adapted to be installed by the user or the system can be adapted to be installed by professionals for instance in a car garage. A typical situation can be that the plug or the socket of the existing system on a vehicle or on a trailer or both needs replacement due to malfunction, and it is then replaced by a system according to the invention. To adapt the electrical coupling system to be a suitable replacement kit the system can be equipped with electrical connectors to facilitate an easy connection between the signal converters 20, 30 and the existing multiconductor systems 3, 4 of the vehicle 1 and the trailer 2. In one possible embodiment, as seen in Fig. 4, the trailer signal converter 30 is comprised inside a replacement plug 50,

30 and the vehicle signal converter 20 is comprised inside a replacement socket 40, 20. The replacement socket 40, 20 and the replacement plug 50, 30 is equipped with easy to connect electrical connectors 55, so that after removing the prior art plug and socket the 7 or 13 wires can easily can be terminated in the replacement socket and replacement plug. The connections between the replacement plug and socket can be conductive surfaces or an inductive coupling.

If the driver or owner of the vehicle is to install the electrical coupling system 10 then the system can be adapted for an easy plug and play installation. The system can then be fully integrated in a socket housing 44 and a plug housing 54. Socket 40 can in such a case be an adapter that fits into the existing prior art socket and comprise the vehicle signal converter 20. The mating plug 50 can likewise be an adapter that fits onto the existing prior art plug and comprise the trailer signal converter 30. The transmission of power and control signal between the socket 40 and the plug 50 can as previously described either via contact surfaces (42,43, 52, 53) or via an inductive coupling.

Another possible way of adopting the electrical coupling system 10 into vehicles 1 and trailers 2 is to install the system instead of an existing prior arts system during assembly of new vehicle and trailers.

SerDes modules can be used both when the control signals are transferred via contact between conductive surfaces and when control signal is transferred inductive.

Although the preferred embodiment is to provide a ground conductor that passes through the socket 40 and the plug 50, other means for grounding can be used. An example of such means for grounding the trailer multi conductor system 4 is to provide grounding through the mechanical trailer coupling. In such a case the current return will pass through the mechanical parts of the coupling, leaving the socket 40 and the plug 50 each with only one corresponding contact surface 42, 52, or only an inductive coupling for the control signals and power.