A lighting system for signalling on a motorcycle

Abstract

The invention relates to a lighting system, such as blinkers or brake lights, for motorcycles and a method for manufacturing thereof. The lighting system comprises a lighting unit with an elongated electronic circuit board with at least two light emitting diodes (LED). The LEDs are arranged to emit in a direction generally away from the exterior side of electronic circuit board. A heat sink has a proximal end (40,44) located in contact with the lighting unit, the heat sink having one or more heat sink distal ends (27,31). The lighting system also includes a fastening unit (27) for fixing the lighting system to the motorcycle and an electric connector (31,131) connected to the electronic circuit board for connecting to electric wiring of the motorcycle. An overmold (23) formed from a moldable material encapsulates the lighting unit completely, wherein the overmold encloses the proximal end of the heat sink. The distal end of the heat sink, the fastening unit and the electric connector extend out of the overmold.

Description

A LIGHTING SYSTEM FOR SIGNALLING ON A MOTORCYCLEBACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates to lighting systems, specifically signal lighting, for motorcycles, such as an electric motorcycle, and method of manufacture thereof. The invention relates to a light emitting diode (LED) lighting system and methods of manufacture thereof. Also, the invention pertains to signalling lighting system for use in automotive systems and automotive system incorporating the lighting system, in particular in electric motorcycles and specifically offroad electric motorcycles2. Description of the Related Art

[0002] Traditional lighting systems used in motorcycles, including blinkers and headlights, often rely on rigid components such as plastic housings and external mounting structures. While these components serve their purpose, they are typically prone to breakage, especially in the event of impacts or during prolonged use. The materials used in conventional motorcycle lighting systems may lack flexibility, which limits their ability to seamlessly integrate with the bodywork of the vehicle. Additionally, these systems frequently suffer from issues such as water or condensation entering the air volume inside the light unit, leading to degradation in light quality and performance over time. As such, there is a significant need for an innovative, durable, and integrated solution that overcomes these challenges. Specifically, such a solution should combine structural flexibility, resistance to impact, and efficient light performance, while also minimizing the risk of water ingress and reducing manufacturing complexity.

[0003] LED lighting systems have emerged as a promising alternative due to their energy efficiency, durability, and compactness. However, even with these advantages, LED lighting systems for motorcycles often require advanced housing and thermal management solutions to ensure long-term reliability and optimal performance. Existing systems face challenges related to thermal dissipation, mechanical stability, and environmental resistance. For example, traditional LED housings often need additional components and enclosures, which can increase the overall size, weight, and complexity of the lighting system.BRIEF SUMMARY OF THE INVENTION

[0004] The present invention addresses these problems by providing a lighting system, such as blinkers or brake lights, that can be mounted on motorcycles including electric motorcycles (EMC).

[0005] The lighting system comprises a lighting unit, a heat sink contacting the lighting unit, an electrical connector and a fastening unit. According to a broad aspect of the invention an overmold encloses or encapsulates the lighting unit and a proximal end of the heat sink. Theovermold encloses proximal ends of the electrical connector and of the fastening unit. Distal ends of the heat sink, of the electrical connector and of the fastening unit extend from the overmold. The overmold comprises a moldable material, such as a plastic. The disclosed invention addresses at least some of the indicated challenges by providing a robust, thermally managed LED lighting system with an overmold. The overmold encloses the lighting unit covering and directly contact the lighting unit that comprises light emitting diodes and an electronic circuit board. The overmold eliminates the traditional enclosure and air volume within the lighting unit. By removing the air volume and replacing the enclosure with a low thermally conductive material, for example silicone, the system effectively prevents water or condensation from entering the signal lighting system, mitigating the risk of moisture-related issues that are common in traditional designs. Moreover, the use of said materials significantly enhances its impact resistance. The distal end of the heat sink, parts of the fastening unit and parts of the electric connector extends from the overmold, but are anchored in the mold.

[0006] In addition to the structural benefits, the lighting system's design provides thermal management through the efficient dissipation of heat. Heat is conducted, preferably by contacting, away the lighting unit by the heat sink to the distal end of the heat sink that extends from the overmold. This ensures that the lighting unit operates within optimal temperature ranges, preventing overheating and maximizing their lifespan.

[0007] Overall, the invention provides an innovative solution that meets the growing demand for durable, efficient, and environmentally resistant lighting systems in motorcycles and other vehicles.

[0008] In an embodiment, the lighting system has a lighting unit that comprises at least one elongated electronic circuit board. The electronic circuit board has at least one, preferably at least two light emitting diodes (LED). The at least two LEDs are positioned along a longitudinal direction of the elongated electronic circuit board. The at least one, preferably at least two LEDs are mounted on an exterior side of the electronic circuit board that optically interfaces with ambient environment during operation. The LEDs are arranged to emit in a direction generally away from the electronic circuit board. Opposite the exterior side, the electronic circuit board has an interior side. Having several LEDs positioned at a distance from each other on the exterior side of the printed circuit board, heat is generated at separate locations on the board.

[0009] LEDs are known for their high energy efficiency, making them particularly beneficial for electric vehicles (EVs), where power consumption is a key concern. However, the invention is not limited to the use of LEDs as light source in the lighting units. Any light source can be used. LEDs consume less power compared to traditional lighting technologies like incandescent or halogen bulbs, which is crucial for maximizing the range and performance of electric vehicles by reducing the overall energy load on the vehicle’s battery. LEDs have a smaller form factor compared to traditional lighting technologies. This compactness allows for easier integration into the vehicle's design, reducing the overall weight. For electric vehicles, especially two-wheeledelectric vehicles, maintaining a lightweight design is critical for maximizing performance and battery life.

[0010] In an embodiment, the lighting system has a heat sink. The heat sink has proximal end located close to, preferably in contact, with the lighting unit. The heat sink can contact the electronic circuit board and / or the LEDs. The heat sink also has one or more heat sink distal ends. The heat sink is configured to conduct heat away from the lighting unit to the one or more heat sink distal ends.

[0011] In embodiments, the heat sink distal ends are connected, preferably integrally, to the proximal end via a middle part of the heat sink. The distal ends are located away from the proximal end contacting the lighting unit. A suitable heat conducting material is used for heat conduction. In particular in combination with LEDs and signal light homologation, heat sinks in lighting systems allow the LEDs to stay on for a period longer than 30 minutes in order to pass the quality control and security checks for automotive systems.

[0012] Also, the heat sink is partially encapsulated in the overmold. The proximal parts of the heat sink are encapsulated. The lighting unit and heat sink are preferably connected to each other before encapsulating both with the overmold. By encapsulating the lighting unit and heat sink parts, the respective positions and the connection between lighting unit and heat sink are protected. The overmold will provide structural strength and will lock the heat sink and lighting unit in position. As a result, the connection of heat sink to lighting unit can be embodied with reduced weight and strength.

[0013] In an embodiment, the lighting system has a fastening unit for fixing the lighting system to the motorcycle or EMC. The fastening unit can allow fixing to the body, frame or bodywork of the electric motorcycle. The fastening unit can comprise clamps, fixation units or screw thread at a distal end extending from the overmold. The fastening unit allows quick replacement of the lighting system in case of a breakage. By encapsulating the fastening unit partially in the overmold structural strength for positioning the fastening unit in the lighting system can be provided by the overmold.

[0014] In an embodiment, the lighting system has an electric connector connected to the electronic circuit board for connecting to the electric wiring of the motorcycle. The electric connector allows power supply from the motorcycle to the lighting unit. The electric connector is partially encapsulated by the overmold. Distal ends extend from the overmold and can be connected to the electrical wiring of the automotive system, such as the EMC.

[0015] In an embodiment, the lighting unit comprises an overmold formed from a moldable, material that preferably has low thermal conductivity. Such an overmold provides impact resistance, which protects the lighting unit and heat sink. Preferably, the overmold material is at least partially transparent or at least partially optically clear. Many plastic materials will diffuse light. An overmold that provides light diffusion results in enhanced visibility of the lighting unit for other users on the road.

[0016] According to embodiments of the invention, the overmold encloses the lighting unit completely. This provides the impact resistance and dirt protection for the lighting unit. In embodiments, the overmold encloses the proximal end of the heat sink, while the distal end of the heat sink extends at least partially from the overmold. This allows dissipating heat by conduction form the proximal end to the distal end of the heat sink and subsequent radiation or convection of that heat to the environment.

[0017] In embodiments, also the fastening unit and the electric connector extend from the overmold. This allows mounting / fixing the lighting system to the EMC and an electrical connection for power supply. Parts of, preferably proximal parts or anchoring parts, the fastening unit are enclosed by the overmold in order to provide a secure connection of the fastening unit to the overmold and lighting unit.

[0018] With the lighting systems of the invention, the inventors have removed the enclosure and air volume inside the light unit. By doing so, the risk of water or condensation entering the system is effectively removed. The conventional enclosure and air volume are replaced by a solid overmold made of a moldable, low thermally conductive, and at least partially transparent material. This overmold serves multiple functions, including providing mechanical protection, thermal insulation, and light diffusion. The result is a lighting system that is impact-resistant. The lighting system can also be seamlessly integrated into various parts of the vehicle, such as the front mask (part of the bodywork and front light carrier) or rear blinkers or lights. This integration is made possible by the overmold, which acts as a flexible and nearly indestructible structural component, enhancing the overall durability and strength of the system. The overmold ensures that the lighting system can withstand harsh environmental conditions, including vibrations, impacts, and exposure to the elements, while maintaining the system's integrity.

[0019] The overmold is in direct contact with the lighting unit and the heat sink. This contact ensures that there is no air or water infiltration into the system, effectively sealing the interior components and providing a watertight and air-tight barrier. In one embodiment the overmold is provided as a solid, continuous overmold structure in respect to the lighting unit. The overmold prevents the intrusion of liquid to the lighting unit. This sealing is highly beneficial as it protects the internal electronics from moisture, dust, and other environmental contaminants that could negatively affect the performance or longevity of the lighting system.

[0020] In embodiment of the invention, the moldable, preferably low thermally conductive, material is silicone. The term "silicone" as used herein refers to an optical grade silicone material having a Shore 00 hardness value in the range of between 60 and 100. As will readily be understood, these values range from soft to medium hard and will affect the pliability, flexibility and durability of lens arrays made from such materials. A material that provides light diffusion results in enhanced visibility. Preferably, the overmold according to the present invention is made of silicone. The silicone material is characterized by a luminous transmittance of at least 90%, with specific light-diffusing elements incorporated to achieve a level of diffusion that is finely tuned for each application. The diffusion properties of the silicone material ensure uniform lightdistribution, effectively reducing hotspots and improving visibility in various optical applications. In addition to the light-diffusing properties, the silicone material has a density of approximately 1 .06 g / cm3, which contributes to the material’s lightness and mechanical strength. The material also demonstrates excellent resistance to ultraviolet (UV) light, thereby enhancing its durability in outdoor and high-light-exposure environments. The yellowing index of the material is less than 5, as measured at greater than 6000 hours according to SAE J2527, ensuring that the silicone maintains its optical clarity and aesthetic quality over time. Furthermore, the silicone material exhibits high stability under thermal stress and is resistant to environmental aging, which is critical for maintaining consistent performance in long-term use. The combination of high luminous transmittance, controlled diffusion, UV resistance, low yellowing index, and thermal stability makes the silicone material highly suitable for use in optical applications, including but not limited to lighting diffusers, lens arrays, and other components where enhanced visibility and consistent light diffusion are required.

[0021] Alternatively, the overmold may be made from other light-diffusing materials, including but not limited to polycarbonate (PC), acrylic (PMMA), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), polyvinyl chloride (PVC), nylon (polyamide) or fluoroplastics such as ETFE or PTFE. There materials provide suitable light diffusion properties while maintaining durability, flexibility, and impact resistance, making them effective for enhancing visibility in a variety of applications.

[0022] The heat sink is in high thermal communication with the at least one circuit board assembly. The thermal communication facilitates the transfer of heat away from the circuit board assembly to maintain operational temperature within a predetermined range.

[0023] The heat sink may be made of any material suitable for dissipating heat from the LED light system. In one preferred embodiment, the heat sink is made of aluminium. Aluminium effectively dissipates heat generated by the LED, maintaining optimal operating temperatures and extending the lifespan of the lighting system. Aluminum provides a high strength-to-weight ratio, reducing the overall weight of the system, which is crucial for applications requiring lightweight designs. In addition, aluminium's natural oxide layer makes it resistant to corrosion, improving the durability of the heat sink, especially in harsh environmental conditions.

[0024] Alternatively, the heat sink is made from other suitable heat dissipating material including but not limited to copper, graphite, copper alloys e.g., brass and bronze, nickel-plated steel, diamond or diamond like-carbon. Graphene, aluminium alloys, aluminium nitride, silicon carbode, magnesium alloys, titanium, zinc, beryllium copper, or ceramic.

[0025] In the context of a lighting unit having LEDs, thermal management is critical for ensuring the performance, reliability, and lifespan of the LEDs. LEDs generate heat during operation, primarily at the junction where light is emitted. This heat, if not properly managed, can degrade the LED’s performance and shorten its lifespan. Moreover, excessive heat can damage the circuit board and other nearby electronic components, leading to system failure. By ensuring the heat sink is in thermal communication with the circuit board assembly, the heat generated bythe LED is transferred efficiently away from the source (the circuit board and LED chips) to the surrounding environment.

[0026] In one embodiment, the electronic circuit board is a printed circuit board. In a further embodiment, the printed circuit board is a metal core printed circuit board. Metal core PCBs are often chosen for better heat dissipation. Moreover, a metal core PCB provides higher mechanical strength and stability compared to standard PCBs, reducing the risk of warping or failure. In embodiments, proximal ends of the heat sink are connected to longitudinal ends of the elongaged metal core PCB. This prevents light blocking by the heat sink, while still allow high and sufficient heat conduct.

[0027] In one embodiment, the at least one fastening unit is partially enclosed by the overmold. Partially encapsulating the fastening unit into the overmold simplifies the assembly of the pars and combines structural and optical components into a single unit. Moreover, this approach eliminates the need for additional mounting of hardware, reducing the overall weight of the assembly. The encapsulated part of the fastening unit is locked / anchored in the overmold.

[0028] In an embodiment, the heat sink has a middle part that connects the proximal end to the distal end. The middle part extends along the interior side of the electronic circuit board. The middle part can contact the interior side of the PCB for heat conduction. This increases the heat dissipation from the LEDs.

[0029] In embodiments, the one or more distal ends of the heat sink extend from the overmold away from the interior side. This allows radiating the light in the exterior direction, while heat is dissipated at the interior side. In embodiments, the one or more distal ends of the fastening unit and / or of the electrical connector extend from the overmold away from the interior side or they extend in a direction generally perpendicular to the interior and exterior side. In any of these directions they don’t interfere with the radiated light.

[0030] In embodiments, the proximal end of the heat sink comprises one or more clamps for enclosing the lighting unit. Preferably, the clamps enclose the electronic circuit board. This allows easy assembling. The clamps allow locking the circuit board and lighting unit is a predefined position with respect of the heat sink. This reduces the complexity assembly of the lighting system according to the invention.

[0031] In embodiment, the heat sink is formed with one or more upstanding walls forming a pocket, wherein the pocket is configured to receive the electronic circuit board. This allows contacting the electronic circuit board from several sides. This increases the heat dissipation away from the LEDs.

[0032] In an embodiment the fastening unit is part of the heat sink. By providing an integral heat sink with fastening unit, enclosing the heat sink positions the fastening unit in a single action. Reducing the number of parts eases assembling. By integrating fastening means directly into the heat sink, the assembly process is streamlined, reducing the complexity of manufacturing and installation. In addition, a heat sink that also is embodied as a fastening component can enhancethermal performance by ensuring better contact with the mounting surface, aiding heat dissipation.

[0033] In one embodiment, the electric connector comprises a cable guidance piece. The cable guidance piece can be for example in the shape of a tube or a ring. A tube or ring can be provided, with the electric wiring received in the opening of the tube or ring. The cable guidance piece is partially molded into the optical silicon overmold. A cable guidance piece provides a structured path for the cables, preventing tangling or damage while ensuring that the cables are neatly routed. By molding the cable guidance piece into the overmold, the system benefits from a more durable, integrated design that protects the cable and the electrical connections from environmental stressors like moisture, dust, and mechanical wear.

[0034] In one embodiment, the fastening unit and electric connector extend from one and the same side of the overmold. That side of the lighting system is connected to the motorcycles, being proximal to the motorcycle The opposite side of the signal lighting unit is then distal from the bike and is best visible for other users for who the signals are intended.

[0035] In embodiments, the opposite side, distal from the connection to the motorcycle, of the overmold is formed by a band of light diffusing material extending at least 0.1cm, preferably 0.4cm away from the lighting unit and heat sink in the opposite direction. The band is integrally formed of moldable material, diffusing light. The band connects the frontside of the overmold (corresponding to an exterior side of the PCB) to a backside of the overmold. As a result, diffuse overmold material extends along the opposite side of the overmold and that band will light up when the LEDs radiate, increasing visibility.

[0036] In embodiments, the fastening unit comprises a passage, preferably tubular, that receives the electric connector. By integrating the passage for the electric wiring in the fastening unit, the wiring is protected without using an additional piece.

[0037] In embodiments, the fastening unit comprises one or more anchors. The anchor(s) are designed to ensure a secure and stable attachment between the fastening unit and the overmold. The anchor(s) are strategically placed on or around the fastening unit to enhance its mechanical engagement with the overmold material. By enclosing the one or more anchors by the overmold, the anchors are fixated with respect to the overmold material and the lighting unit. The anchors provide a mechanical interlock that improves the stability and securing of the LED lighting system when mounted to an external device.

[0038] In one embodiment, the anchor can be in the form of a ring, although other geometric shapes and configurations may be utilized depending on the specific design requirements. In embodiments, the anchor can be configured with features such as interlocking teeth, grooves, or protrusions, which are specifically intended to engage with the overmold. These features help to resist lateral or axial movement of the anchor relative to the overmold, preventing the anchor from detaching or becoming dislodged under stress, vibration, or external forces. As such, the anchor provides mechanical stability and significantly reduces the likelihood of theovermold shifting or separating from the fastening unit over time, particularly in demanding operating conditions.

[0039] The anchor's material can be selected for its compatibility with the overmold material, such as metals, reinforced plastics, or other materials that allow for an optimal mechanical connection. Anchors can also be made from the same material as the heat sink.

[0040] In one embodiment, the fastening unit is distanced from the heat sink and the lighting unit, by at least 0.1 cm, preferably 0.4cm, more preferably at least 1cm, more preferably at least 2cm. By providing a disconnect between the fastening unit and the lighting unit with heat sink, that disconnect is bridged by the overmold material. Preferably, the overmold material has some flexibility. As a result, the disconnect allows flexing of the fastening unit with respect to lighting unit with heat sink. This reduces the risk of breakage. This design feature provides a notable benefit in collision scenarios or environments where the lighting system may be subject to physical impact. The flexing of the fastening unit, facilitated by the overmold material, reduces the forces exerted on the more delicate components of the lighting system, such as the signal lighting elements and circuitry. In the event of a collision, the overmold flexibility acts as a shock absorber, decreasing the risk of physical damage to the lighting system and enhancing the durability and longevity of the overall product.

[0041] Moreover, the flexibility of the overmold material enables it to act as a buffer zone, absorbing and dissipating mechanical stresses that may otherwise be transferred directly to the fastening unit. As a result, the overmold material not only maintains structural integrity but also isolates the fastening unit from thermal expansion or contraction effects that may occur in the heat sink or lighting unit, which can vary with operational conditions such as temperature fluctuations.

[0042] In embodiments, the electrical connector extends between the lighting unit and fastening unit that are disconnected, preferably centrally through the overmold. The wiring can also flex. The disconnect is specifically advantageous for the back signal lighting of an electric motorcycle.

[0043] In embodiments, the heat sink comprises at least one or more anchors enclosed by the overmold. This results in a stable position of the heat sink in the overmold. This is particularly advantageous in combination with the disconnected fastening unit. The at least one or more anchors of the heat sink can be positioned close but at a distance from the fastening unit.

[0044] In embodiments, the overmold has a generally elongated shape. In embodiments the shape is generally tubular. In embodiments, the fastening unit protrudes from the overmold in a longitudinal direction and forms the proximal end of the signal lighting system to be connected to the motorcycle frame. In this embodiment, the elongated electronic circuit board generally extends in the longitudinal direction of the overmold. A row of LEDs also extends generally in the longitudinal direction.

[0045] The heat sink can comprise at least one distal end formed as a radiation surface protruding out of the overmold. In embodiments, specifically of rear blinker lights, the radiationsurface can extend generally along the longitudinal direction of the elongated overmold. In embodiments, at least two opposite side of the lighting system have a radiation surface extending along the longitudinal direction of the elongated overmold, extending over a length that is greater than the length of the lighting unit. The radiation surfaces have two functions: (1) to irradiate some of the heat that is conducted from the proximal parts of the heat sink to the radiation surfaces that extend from the overmold and (2) to block outward light from the lighting unit in the direction from the lighting unit to the radiation surface.

[0046] The radiation surface can extend around the lighting unit in a U-shaped manner, extending over more than 180 degrees. This effectively blocks the radiation towards at least one side. In embodiments, the radiation surfaces extend over 250-290 degrees, allowing radiation to exit from the overmold generally only in a direction away from the exterior surface of the lighting unit. This blocking of light is generally aligned with the homologation regulation for rear signalling lights.

[0047] In a preferred embodiment, the radiation surface of the heat sink extends in a direction generally perpendicular to a plane of the electronic circuit board. The elongated overmold can have a blocked cross-section, with the radiation surface forming one of the sides of the block.

[0048] In embodiments, specifically directed at the rear signal lights of an electric motorcycle, the heat sink has an elongated racket shape. One or more anchors of the heat sink are positioned at the racket handle, whereas two radiation surfaces of the heat sink extend in a generally longitudinal direction. The electronic circuit board is received within a face of the racket shape.

[0049] In embodiments, the aluminum body of the heat sink is configured to block the light from being visible from the front of the vehicle, ensuring that the light is directed exclusively towards the rear of the vehicle corresponding with the direction away from the exterior surface of the PCB / lighting unit. This configuration ensures compliance with regulatory requirements that mandate the control of light direction, preventing any light from being visible from the front and reducing glare for other road users.

[0050] In one embodiment, the LED lighting system is a blinker light. In another embodiment, the lighting system is a brake light. In yet another embodiment, the lighting system is a taillight. Additionally, the lighting system may be configured as a headlight, turn signal, fog light, daytime running light (DRL), reverse light, or a marker light. Each of these lighting systems is configured to meet specific lighting and visibility requirements, ensuring effective signaling, safety, and visibility for the vehicle in various driving conditions.

[0051] Another aspect of the invention comprises a method for manufacturing a signal lighting system for a motorcycle. The method comprises: providing lighting unit formed by an electronic circuit board with at least two mounted light emitting diodes (LEDs), providing a heat sink with a proximal end and a distal end,- connecting the proximal end of the heat sink in contact with the lighting unit;- connecting an electrical connector to the electronic circuit board, and providing a fastening unit for connecting the lighting system,- overmolding said lighting apparatus and said heat sink with a moldable material, fully enclosing the lighting unit, partially enclosing the heat sink with the distal end extending from the overmold, and partially enclosing the fastening unit and the electrical connector.

[0052] The present disclosure uses moldable material to enclose the heat sink and the lighting unit with LEDs.

[0053] An electrical connector extends from the overmold and is partially enclosed. This allows connecting the driver electronics to the printed circuit board. The LEDs can radiate light The LED's can cooperate with a secondary optic that may be attached to focus the light as desired.

[0054] An injection molding process may be used during manufacturing to assemble the signal lighting system. The signal lighting system can be assembled by providing in the same molding cell the low thermally conductive plastic, the printed circuit board with LEDs and the heat by incorporating automation techniques and robotics. A distal part of the heat sink is in contact with the mold and is not overmolded. Also, an electrical connector and / or a fastinging unit can be partially encapsulated with the moldable material in the mold. This produces an assembled LED lamp that is thermally and mechanically reliable with minimal to no added manufacturing costs and time. The manufacturing process from device to device can thus be made consistent and repeatable which again increases device and product reliability and repeatability. This automated assembly can therefore significantly reduce manufacturing and assembly time and costs of the LED lamp. The combination of these factors significantly reduces the device first cost to the consumer.

[0055] According to yet a further aspect, the invention is directed to an electric motorcycle comprising the at least one of signal lighting system according to any one of claimsBRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only exemplary embodiments of the disclosure and are therefore not to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 is a schematic perspective view of a motorcycle that equipped with lighting systems according to embodiments of the invention;FIG. 2a is a schematic perspective view of a lighting unit with heat sink according to an embodiment of the invention;FIG. 2b is a exploded view of an embodiment of the lighting system for a front blinker according to an embodiment of the invention;FIG. 3 is a cross-sectional view along Ill-Ill in FIG 2B of the lighting system according to an embodiment of the invention;FIG. 4 is a schematic perspective view of a motorcycle that equipped with lighting systems according to embodiments of the invention;FIG. 5 is an exploded and perspective view of a rear blinker lighting system according to a further embodiment of the invention.FIG. 6 is a cross section along V-V in FIG 5a.

[0057] The following is a description of certain embodiments of the invention, given by way of example only and with reference to the drawings. The drawings are not necessarily to the actual scale and only serve the purpose of illustrating necessary teachings for implementing the present invention.DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0058] Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. A reference to an embodiment in the present disclosure can be a reference to the same embodiment or any other embodiment. Such references thus relate to at least one of the embodiments herein.

[0059] Reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.

[0060] The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used.Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only and is notintended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification.

[0061] Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.

[0062] Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims or can be learned by the practice of the principles set forth herein.

[0063] Referring to FIGs. 1 and 4, perspective views of a saddle-type vehicle 10 are shown. The saddle-type vehicle 10 particularly is a motorcycle. Typically, the motorcycle 10 comprises a front wheel 17, a rear wheel 19 and a seat 14. In various embodiments, the motorcycle 10 comprises a wheel fork 16 supporting the front wheel 17. The wheel fork 16 and the front wheel 17 are configured to rotate a rotational axis of the front wheel 17 with respect to a rotational axis of the rear wheel 19 in order to steer the motorcycle 10.

[0064] In various embodiments the motorcycle 10 comprises a structural frame 12 supporting the seat 14 and the engine 13. In various embodiments the rotational axis of the rear wheel 19 has a fixed orientation with respect to the structural frame 12. In various embodiments the wheel fork 16 is connected to the structural frame 12 by means of a steering joint. The steering joint preferably has a rotational axis perpendicular to both, the rotational axis of the front wheel 17 and to the rotational axis of the rear wheel 19.

[0065] The steering 15 is configured to rotate the wheel fork 16 about the steering joint with respect to the structural frame 12. By rotating the wheel fork 16 about the steering joint with respect to the structural frame 12, the rotational axis of the front wheel 17 is rotated with respect to the rotational axis of the rear wheel 19.

[0066] In various embodiments the wheel fork 16 comprises a front suspension such as a telescoping fork having a spring for elastic deflection and a damper for shock absorption. In various embodiments, the motorcycle 10 comprises a rear suspension 18 suspending the rear wheel 19 with respect to the structural frame 12. In various embodiments the rear suspension 18 comprises a spring for elastic deflection and a damper for shock absorption. In various embodiments the front and rear suspensions are adjustable by preloading the respective spring and / or manipulating the respective damper.

[0067] In various embodiments, the motorcycle comprises a bodywork 11 covering a portion of the structural frame 12 and preferably a portion of the engine 13. In various embodiments, the seat 14 is arranged on the body work 11 .

[0068] In various embodiments the engine 13 comprises an energy source. In various embodiments the engine 13 is an electric engine and the energy source is a battery such as a secondary battery. In further embodiments the engine 13 is an internal combustion engine and the energy source is a fuel tank. In various embodiments, the engine 13 drives the rear wheel 19 by means of a chain drive, a belt drive or a shaft drive.

[0069] In various embodiments, the engine is associated with a motorcycle data processing unit configured to centrally determine, process, and control at least portions of the operation of the motorcycle 10.

[0070] In various embodiments the seat 14 is configured to accommodate the user. The steering 15 is configured to receive a user input for adjusting a motorcycle function and / or to display at least one state indicator of the motorcycle 10.

[0071] Near the front, a front fender 20 having an upwardly extending front part 20b is shown. On the lateral sides of the front part 20b, two blinkers, right 22a, left 22b, are mounted.

[0072] Near the rear side of the motorcycle 10, rear blinker 21 is mounted extending in the lateral direction from the body frame 12. Blinkers 21 , 22a and 22b are example embodiments of the lighting system including a LED lighting unit according to the invention.

[0073] The blinkers 21 ,22a, b are fixed to the frame or fenders via suitable connectors. A mounting piece extending from the overmold of the lighting system is fixed to the frame or fending. Further electrical connectors extending from the overmold are connected to the electrical wiring of the motorcycle and this allows controlling the blinker by the user via user interface mounted close to the handgrips on the steering 15.

[0074] FIG.2a shows a detail of a blinker 22. An overmold 23, shown by a dotted line, is formed from optical silicone. The overmold 23 encapsulates the lighting unit.

[0075] Inside the overmold 23, the heat sink 24 is visible. The heat sink comprises two clamps 27 extending from the overmold 23. Also, exending from the overmold 23 and connected to the heat sink 24, is electrical connector 31 formed by a tube in which electrical wires can be received that are connected to the electronic circuit board and the LEDs that are completely encapsulated by overmold 23.

[0076] FIG.2a shows distal parts 34,35, shaped like mushrooms, of the heat sink 24 extending from the overmold 23. Parts extending from the overmold material are shaded with dots in FIG. 2a. Also, clamps 27 and connector 31 extend from the overmold and are shown shaded with dots. Connector 31 is a protective tube in which wires can be received.

[0077] Proximal and middle parts of heat sink 24 are embedded in the overmold material. The proximal and middle parts have an elongated shape and extend along the interior surface of the PCB, on the opposite side of the LEDs that are mounted on the exterior side.

[0078] On the side away from the clamps 27, a band 39 of thickness 41 extends along the edge 38 of the heat sink 24. The band 39 extends at least 0,5cm from the heat sink. The band 39 will light up as result of the diffusing effect of the silicon, despite the LEDs being directed away from the exterior side. The band 39 forms a J-shaped band along the heat sink 24. The band 39 will be an outer rim of the front shield 20b, when the lighting system 21 b is mounted in the front shield 20b. This band 39, which connects overmold material on the front side and on the back side of the lighting system 22, will light up as a result of the LEDs, and will thus result in an outer rim of the front shield 20b that is visible from the front and from the back. From the back, the visibility is limited, as only diffused light will be radiated.

[0079] Clamps 27 are partially enclosed. In this embodiment, the arms 57 connecting the clamping end 27 to the heat sink 24, are encapsulated by the overmold. The overmold 23 is formed with recesses allowing movement of the clamps also near the root parts 57 of the clamps 27 connected to the heat sink 24. This allows the clamps 27 to move in a sideward direction 58. to clamp onto a frame part of the motorcycle.

[0080] The heat sink 24 and PCB extend in the longitudinal direction 58.

[0081] FIG.2b shows an exploded view. With respect to FIG.2a, the lighting is rotated 180 degrees. The lighting unit 110 is shown with several LEDs 112 on an exterior surface 115 of PCB 100. Although not shown a wire can connect to the electrical circuit of the motorcycle and enter the overmold 23 via tubular connector 31 and be connected to the PCB 115 for energising the LEDs 112.

[0082] PCB 100 is clamped into a pocket 42 formed in heat sink 24 surrounded by rims 44. Positioning the PCB 100 into the pocket 42 will result in being clamped 190,191 by clamps 40 positioned at longitudinal ends of the elongated PCB 100 and heat sink 23.

[0083] The clamps 40 and rims 44 from the proximal parts of the heat sink 24, positioned closest to the LEDs 112. The middle part of the heat sink 23 forms the pocket 42 and connects the proximal parts 40,44 to the distal parts such as clamps 27, connector 31 and mushrooms 34,35 that extend from the mold and can thus radiate heat to the environment more easily.

[0084] FIG.3 is a cross-sectional view along line Ill-Ill in FIG.2b. The cross-section extends along the longitudinal direction of heat sink 24 and PCB 100 and generally along the row of LEDs 112 positioned on the exterior side 115 of PCB.

[0085] The cross-section shows the exterior side of the PCB 100 with LEDs 112 encapsulated by mold material 23 and the interior side 114 of the PCB 100 facing the bottom of pocket 42. The bottom of pocket 42 is also the middle part of the heat sink The interior side 114, opposite the exterior side 114 contact the middle part of the heat sink 24. That middle part is also connected to mushrooms 34,35, which extend from the overmold 23. The parts extending from the overmold 23 are indicated by dotted shading.

[0086] Although the LEDs 112 face in a direction away from the exterior surface 115 of the PCB, the diffusing effect of the material of the overmold results in the light being diverted and also being diverted to the band 39.

[0087] A rear signalling light system 21 is shown in FIG. 4 connected to the frame of the motorcycle. FIGs. 5 and 6 show embodiments of the rear signalling lighting system 21.

[0088] FIG. 5 shows a detail of a rear lighting system for blinkers on a motorcycles. Electric connector 131 comprising electric wires for providing energy for the LEDs 112 can be connected to the electric circuit of the motorcycle. The rear lighting system 130 has an longitudinal direction 158.

[0089] Fastening unit 117 can be connected to frame part or the rear fender of the motorcycle. Fastening unit 117 has a longitudinal channel for receiving the electrical wires 131. Fastening unit 117 forms a proximal part of lighting system 130. Fastening unit 117 has at a distal end rings 134 that are encapsulated by the overmold 116. The overmold 116 completely encapsulates the rings 134, thereby providing an anchor for the fastening unit 117 in the overmold.

[0090] Only the electrical connector with wires 131 extends distally from the rings 134 of the fastening unit 117 towards anchor rings 119 that are part of the heat sink 118. A distance 150 is bridged by molded material and electrical connector 131 between the distal rings 134 and rings 119 of the heat sink. This bridging part of molded material provides flexibility between fastening part 117 and the heat sink 118 with lighting unit 110. This allows flexing of the distal part with LEDs 112 and heat sink 118 with respect to the fastening unit 117, preventing breakage.

[0091] Wiring 131 is connected to lighting unit 110 comprising of a PCB 100 with LEDs 112. The lighting unit 110, the PCB 100 and the row of LEDs 112 extend in the longitudinal direction 158 of the elongated rear lighting system 130 of FIG. 5.

[0092] Two screws 160,161 connect the PCB 100 with heat sink 118. This allows transferring heat from the PCB generated by the LEDs 112 to the heat sink 118, especially in case of a metal PCB. The screws 160,161 , the proximal parts of the heat sink 118, the anchor 119, and the lighting unit 110 are encapsulated by the overmold 23. In FIG. 5, the overmold plastic is shown as plastic body 116.

[0093] Proximal parts of the heat sink 118 are connected or positioned in proximity of the LEDs 112. The proximal parts can conduct heat towards distal elements of the heat sink 118 that are not covered by the overmold 23.

[0094] Heat sink 118 comprises three surfaces 113,123 124, which are distal parts of the heat sink 118 that extends out of the overmold 23. The radiation surfaces 113,123,124 can radiate heat to the environment, thereby providing a cooling of the LEDs 112.

[0095] The radiation surfaces 113 and 123 are two elongated surfaces extending along, at opposite sides, the lighting unit 110. Radiation surface 124 connects the two radiation surfaces 113,123 to form a U-shaped cavity, in which the lighting unit 110 extends. The radiation surfaces are longer than the lighting unit 110 in the longitudinal direction 158.

[0096] The radiation surfaces 113,123,124 have one open side, which is the side from which radiation from the LEDs can exit the lighting system 130. The radiation surface 113, 123, 124 of heat sink 118 have a double function: they block light from the LEDs thereby resulting inlight being radiated in one direction only (to conform with homologation requirements for rear lights on motorcycles) and they are heat dissipation surfaces for removing heat from the LEDs 112.

[0097] Distal end 146 of the lighting system 130 is a radiation surface of the heat sink 118. Radiation surfaces 113 and 123 form, together with distal end 146, a racket shape that receives the LEDs in the racket pocket, with the proximal end of the heat sink forming the handle of the racket.

[0098] FIG. 5 and FIG. 6 show further details, where FIG. 5 shows a plane VI-VI, which shows the cross-section of FIG.6

[0099] FIG. 6 shows the cross-cross section the radiation surface 124 that connects the radiation surfaces 113,123. Radiation surface 124 faces the interior surface 114 of the PCB 100. Also that space, between interior surface 114 and PCB 100 is filled with moldable material. a

[0100] Further modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.

Claims

CLAIMS1. A lighting system (22,130), such as blinkers or brake lights, for motorcycles, comprising: a lighting unit (100,110) comprising at least one elongated electronic circuit board (11), the electronic circuit board having at least two light emitting diodes (LED) (1 12) positioned along a longitudinal direction of an exterior side of the elongated electronic circuit board, wherein the at least two LEDs are mounted on an exterior side of the electronic circuit board that optically interfaces with ambient environment during operation and arranged to emit in a direction generally away from the electronic circuit board, said electronic circuit board having an interior side opposite the exterior side; a heat sink (24), wherein the heat sink has a proximal end (40,44) located in contact with the lighting unit, the heat sink having one or more heat sink distal ends (27,31) connected to the proximal end, wherein the heat sink is configured to conduct heat away from the lighting unit to the one or more heat sink distal ends, an overmold (23) formed from a moldable material, a fastening unit (27) for fixing the lighting system to the motorcycle, an electric connector (31 ,131) connected to the electronic circuit board for connecting to electric wiring of the motorcycle, wherein the overmold encloses the lighting unit completely, wherein the overmold encloses the proximal end of the heat sink and wherein the distal end of the heat sink, parts of the fastening unit and parts of the electric connector extend out of the overmold.

2. The lighting system according to claim 1 , wherein the moldable low thermally conductive material is silicone and / or wherein the heat sink is made of aluminum and / or wherein the electronic circuit board is a printed circuit board, preferably a metal core printed circuit board.

3. The lighting system according to any of the preceding claims, wherein the heat sink has a middle part that connects the proximal end to the distal end of the heat sink, wherein the middle part extends along the interior side of the electronic circuit board, wherein the one or more distal ends extend from the overmold away from the interior side.

4. The lighting system according to any of the preceding claims, wherein the heat sink comprises one or more clamps (20) for enclosing the lighting unit, preferably for enclosing the electronic circuit board.

5. The lighting system according to any of the preceding claims, wherein the heat sink is formed with one or more upstanding walls (44) forming a pocket (42), wherein the pocket is configured to receive the electronic circuit board.

6. The lighting system according to any of the preceding claims, wherein the fastening unit is part of the heat sink.

7. The lighting system according to any one of the preceding claims, further comprising a cable guidance piece (31), such as a tube, wherein the cable guidance piece partially extends from the overmold.

8. The lighting system according to any one of the preceding claims, wherein the fastening unit and electric connector extend from one side of the overmold and wherein an opposite side of the overmold is formed by a band extending at least 0.4cm away from the lighting unit and heat sink, the band connecting a frontside of the overmold to a backside of the overmold.

9. The lighting system according to any of the preceding claims, wherein the fastening unit comprises a passage, preferably tubular, that receives the electric connector.

10. The lighting system according to any of the preceding claims, wherein the fastening unit comprises one or more anchors, preferably rings, wherein the one or more anchors are enclosed by the overmold.

11. The lighting system according to any one of preceding claims, wherein the fastening unit is distanced (150) from the heat sink and the lighting unit, by at least 0.5cm, preferably at least 1 cm, more preferably at least 2cm, wherein the electrical connector extends between lighting unit and fastening unit, preferably centrally.

12. The lighting system according to any of the preceding claims, wherein the heat sink comprises at least one or more anchors enclosed by the overmold, wherein preferably the at least one or more anchors of the heat sink are positioned proximal, but at a distance from the fastening unit according to claim 11 .

13. The lighting system according to any one of preceding claims, wherein the overmold has a generally elongated, preferably tubular, shape, wherein the fastening unit protrudes from the overmold at a longitudinal end and in a longitudinal direction, wherein the electronic circuit board generally extends in the longitudinal direction of the overmold, and wherein of the at least two LEDs form a row that extends generally in the longitudinal direction.

14. The lighting system according to claim 13, wherein the heat sink comprises at least one radiation surface protruding from the overmold, the radiation surfaces extending generally along the longitudinal direction, wherein the radiation surface is extending form the overmold and wherein the radiation surface is longer than the lighting unit, wherein two radiation surfaces extend along the elongated lighting system, wherein heat sink forms a U-shaped housing surrounding the lighting unit, with the exterior surface of the lighting unit directed towards an opening of the U of the U-shaped housing, wherein preferably the radiation surface also extends in a direction generally perpendicular to a plane of the electronic circuit board.

15. The signal lighting system according to claim 12, 13 or 14, wherein the heat sink comprises an elongated racket shape, wherein the one or more anchors generally are positioned-19- at a racket handle, wherein two radiation surfaces extend in a generally longitudinal direction, wherein the electronic circuit board is received within a face of the racket shape.

16. A method for manufacturing a lighting system for a motorcycle, comprising: providing lighting unit formed by an electronic circuit board with at least two mounted light emitting diodes (LEDs), providing a heat sink with a proximal end and a distal end, connecting the proximal end of the heat sink in contact with the lighting unit; connecting an electrical connector to the electronic circuit board, and providing a fastening unit for connecting the lighting system, - overmolding said lighting apparatus and said heat sink with a moldable low thermally conductive material, fully enclosing the lighting unit, partially enclosing the heat sink with the distal end extending from the overmold, partially enclosing the fastening unit and the electrical connector.

17. An electric motorcycle comprising at least one of LED lighting system according to any one of claims 1-15 or produced by the method according to claim 16.

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