The subject of the invention is a power and telecommunications cable, which has applications especially in residential and public building installations.

Commonly known and used in family housing, as well as in industrial buildings for powering the basic equipment, are single-phase and multi-phase electric power supply installations, using copper wires. The most common are cables consisting of either three - single-phase power supply - or five - three-phase power supply - conductors, where each conductor consists of either one or more individual wires of circular cross-section.

Fiber optic cables are used to transmit data between devices that require it. Of course, there are other types of transmission media for communication between telecommunications devices, such as twisted-pair - a multi-conductor copper cable — or wireless communication, such as using radio waves. Problems with radio wave propagation mean that such communications are used over short distances and are characterized by relatively low data exchange speeds. In addition, solutions that use copper wires for data transmission have greater limitations than fiber optics. Today, the most commonly used medium for data transmission is optical fiber. This is a solution with very high potential, especially when we consider the technological advances in the next generation of fiber optics.

Currently, the most common solution for power supply and ensuring data exchange between electronic devices is a separate implementation of power supply using a dedicated power supply installation and independent implementation of a network for data transmission (usually fiber optic). The result of this approach is a correspondingly large amount of work on the design, implementation and commissioning of two independent installations.

Current trends and ongoing research toward the Internet of Things (loT -Internet of Things') - aim to provide connectivity to almost any electrical device, which poses certain problems when we consider non-stationary devices that require power from the power grid - such as an iron. Currently, wireless transmission - such as WiFi {Wireless Fidelity) or transmission over existing power lines (PLC - Power Line Communication) can be used, but in both cases we are dealing with the generation of electromagnetic fields in the immediate human environment, as well as the generation, induction and propagation of electromagnetic interference.

An undersea cable is known from the description of the U.S. Invention US 4763981 A, which contains at least one optical fiber disposed axially in a tube-shaped solid electrical conductor. A tube-like dielectric cylinder is coaxially disposed about the solid conductor. A load-bearing annulus is coaxially disposed about the dielectric cylinder, which further guards the dielectric cylinder from abrasion and penetration. The whole is embedded in an elastomeric outer jacket.

A communications cable is known from the description of the U.S. Invention US 4896939 A, which contains an optical fiber, a first tubular electrical conductor enclosing the optical fiber, a second tubular electrical conductor enclosing the first electrical conductor, and a dielectric support layer disposed between the conductors. The whole is surrounded by an external protective layer of dielectric material, such as polyethylene.

An instrument cable is known from the description of the U.S. Invention US 5493626 A, which includes an optical fiber, a protective buffer layer surrounding the optical fiber, a protective sheath surrounding the optical fiber and the protective layer, a first insulating layer surrounding the protective sheath, a layer of electrical conductors surrounding the first insulating layer, a second insulating layer surrounding the layer of electrical conductors. Electrically conductive strength member strands surrounding the second insulating layer.

A cable is known from the description of the international invention WO 0241054 Al, which includes an optical fiber comprising a core coaxially surrounded by a cladding. The core may be a glass or a plastic core. The cable also includes an electrical conductor coaxially surrounding the cladding and further includes a sheath coaxially surrounding the electrical conductor. The electrical conductor comprises a first metal layer deposited directly on the cladding, and a second metal layer electrolytically deposited on the first metal layer. In addition, the cable comprises a dielectric sheath coaxially surrounding the second conductive layer.

A shielded multiphase power cable, in particular for mining, with an optical fiber is known from the description of the Polish patent PL 225986 Bl . The cable consists of at least one non-metallic conductive layer, a sealing layer, a separating layer, a filling layer, and at least one metal layer in the form of armor, general shielding, radial sealing, and a center section with a filling, with a center bundle of three single-core cables with individual metal shields, and a single-wire metal core. Inside the tube-shaped single-wire metal core, at least one optical fiber is placed, while preferably the surface of the outer layer is covered with a reflective material or a layer of material with a reflective agent is placed in the outer layer.

A cable is known from the description of the European patent application EP 3327732 Al, which comprises an optical fiber cable, an electric cable and a sheathing. The optical fiber cable comprises an optical fiber and a tubular enclosure which encloses the optical fiber. Each of the electrical cables comprises an electrically conductive interior and an electrically insulating layer enclosing this interior.

A telecommunication-transmission-power cable is known from the description of the Polish patent PL 226979 Bl, which comprises an enclosure for a power cable, a ground cable and a telecommunications line. The enclosure has a shape similar to a polygon, and the telecommunications line is located in the center of this enclosure. In the corners of the enclosure are the power phase conductors and the neutral conductor, in addition to transmission channels. The telecommunications line is a fiber optic cable.

A coaxial signal cable is known from the description of the international invention WO 9422039 Al, which has an optical fiber core comprising an optical fiber clad surrounding the fiber core and a buffer layer of soft polymer. In addition, the cable contains a conductive layer of metal strands spiralled around the core periphery. A layer of insulation surrounds the conductive layer.

State of the art solutions are unsuitable or insufficiently adapted for use in residential and public buildings where both power and telecommunication installations are required, in particular they do not solve the problem of ensuring safety in case of accidental damage to the cable.

A coaxial power and telecommunications cable comprising an optical fiber coaxially surrounded by tube-shaped cylindrical conductors (first and second ones) and further comprising dielectric layers, according to the invention, characterized in that it comprises a third tube-shaped cylindrical conductor coaxially surrounding the second conductor and the first conductor and the optical fiber, said third conductor being a grounding and shielding conductor and one of the other conductors being a phase conductor. Preferably, the first conductor is a phase conductor, and the second conductor is a neutral conductor.

Further advantages are obtained if the cable includes a fourth tube-shaped cylindrical conductor and a fifth tube-shaped cylindrical conductor, which are located coaxially in relation to the optical fiber, between the first conductor and the second conductor, and, in addition, the fourth conductor and the fifth conductor are phase conductors.

Another advantages are obtained if the conductors are made of conductive wires.

Subsequent advantages are obtained if the conductors are formed as a braid. Further benefits are obtained if the conductors are either copper or aluminum conductors.

Another advantages are obtained if the dielectric layers of the cable include internal dielectric layers, which are placed between the individual conductors and between the first conductor and the optical fiber.

Subsequent advantages are obtained when each of the inner dielectric layers, which are between the conductors, consists of two overlapping layers.

Further advantages are obtained when the dielectric layers of the cable include an outer dielectric layer coaxially surrounding the third conductive layer, and there is an inner dielectric layer between the outer dielectric layer and the third conductor.

In some embodiments, the optical fiber is either single-mode or multi-mode fiber.

In some embodiments, the optical fiber is either plastic or photonic-crystal fiber.

The cable according to the invention makes it possible to simultaneously power an electrical device and exchange data with it through an optical fiber, bringing a new quality to installation systems designed for both domestic and structural and industrial applications. Due to the fact that in the solution according to the invention the outer conductive layer is a grounding layer, any damage to the cable - for example, placed in the wall - destroying it cross-sectionally from the outside with an electrically conductive element, as well as in some cases with an element with insulating properties, in terms of damage to the outer insulating layer (contact with the grounding conductor) will not result in a shock hazard. In the event of a deeper damage, where contact is made with the neutral conductor, there is a high probability that a short-circuit will occur between the phase conductors and the grounding and neutral conductors, with the consequent tripping of the electrical protection. This effect is independent of the side, from which the cable is damaged. This solution allows to significantly increase the safety' of the cable use, especially in situations of uncontrolled and unintentional damage of the cable, compared to the traditional multi-conductor power cable (e.g. YDYt) or the commonly used corrugated pipe (protective pipe) and single-conductor cables placed inside it. The solution simplifies the design process of an electrical installation by eliminating the need for separate layouts for power and data. Collision of cables and duplication of outlets are avoided. The execution process is also simplified and less labor-intensive because it is possible to use one set of cables and mounting boxes/outlets. Expanding the installation is also much easier than with standard cable solutions. It is possible to cut the existing cable and install a splitter in this place, or to run a new part of the installation from the existing mounting box. While the process is not too different for a power supply installation, it is for data one. With the traditional solution, the easiest way is to install a new cable to connect a new access point to the switch, which is usually located in a switch-room, which can significantly increase the cost of the installation. The cable according to the invention enables the use of Passive Optical Network (PON) technology. The data transmission is carried out with a single optical fiber, but using two optical wavelengths for different transmission directions. The use of only a single fiber greatly simplifies the implementation of the cabling itself. At the distribution points of the installation, the optical power is divided in a certain ratio and transmitted further - using passive power splitters for optical fibers. As a result, it is possible to create a branch for a new access point at any point in the installation, or to multiply an access point at a single point in the installation. The access point can be the last element of a given installation circuit (terminal mounting box) or an intermediate point (e.g., a pass- through mounting box) or a splitting point (e.g., a branch mounting box). It is possible to install the chosen form of a terminal outlet here, i.e., a power-only outlet (no communication capability; can have the form of a typical power outlet), a data transmission outlet (no power to the receiver, can be one of the standardized optical transmission outlets), and a hybrid outlet that allows power to the receiver and communication with it. Examples of devices that can be mounted directly in the mounting box and that require or may require both power and data transmission are: camera, smoke detector, motion detector, lighting, intercom, power meter outlet, control terminal, control switches, thermostats, etc. Such functionality makes it possible to adapt the proposed installation to support standard, well-known devices.

The use of the cable according to the invention allows to dynamically change the function of a given access point (power, telecommunications or hybrid outlet) by replacing the mounting box cover or the entire integrated device with the cover.

The power and telecommunications cable according to the invention is further explained in the embodiments shown in the figures, wherein Fig. 1 shows the optical fiber cable in isometric view in cross-section through its layers, in the first embodiment; Fig. 2

- the same cable in cross-section; Fig. 3 - the second embodiment in cross-section; Fig. 4

- the third embodiment in cross-section.

The power and telecommunications cable, according to the invention, in the first embodiment, is a single-phase coaxial cable and comprises a single-mode photonic-crystal optical fiber 1 , which is surrounded coaxially by a first tube-shaped cylindrical conductor 2, which is a phase conductor. In addition, the first conductor 2 is coaxially surrounded by a second conductor 3, which is a neutral conductor and is also shaped like a cylindrical tube. The second conductor 3, on the other hand, is coaxially surrounded by a third conductor 4, which is a grounding and shielding conductor and is also in the form of a cylindrical tube. The optical fiber 1 comprises a core la covered with a reflective optical fiber jacket lb and an outer protective layer 1c. The conductors 2, 3 and 4 are in the form of a copper braid and are separated from each other by an inner dielectric layer 5. The cable also has an outer dielectric layer 6 coaxially surrounding the third conductor 4, with the inner dielectric layer 5 between this outer dielectric layer 6 and the third conductor 4.

The power and telecommunications cable, according to the invention, in the second embodiment, is a three-phase coaxial cable and comprises a single-mode plastic optical fiber 1 , which is surrounded coaxially by a first tube-shaped cylindrical conductor 2, which is a phase conductor. In addition, the first conductor 2 is coaxially surrounded by a second conductor 3, which is a neutral conductor and is also shaped like a cylindrical tube. The second conductor 3, on the other hand, is coaxially surrounded by a third conductor 4, which is a grounding and shielding conductor and is also in the form of a cylindrical tube. Between the first conductor 2 and the second conductor 3, a fourth conductor 7 and a fifth conductor 8 are sequentially arranged, each of which is shaped like a cylindrical tube, coaxially arranged with respect to the optical fiber 1 and the other conductors 2, 3 and 4. The optical fiber 1 comprises a core la covered with a reflective optical fiber jacket lb and an outer protective layer 1c. Each of the conductors 2, 3, 4, 7 and 8 is in the form of copper wires arranged at an equal distance from the core 1 a of the optical fiber 1 , the wires of a given conductor 2, 3, 4, 7 and 8 being separated from the wires of the other conductors by an inner dielectric layer 5. Each of the inner dielectric layers 5, which are between the conductors 2, 3, 4, 7 and 8, consists of two overlapping layers of dielectric material. In addition, the cable has an outer dielectric layer 6 coaxially surrounding the third conductor 4. The inner dielectric layer 5 is provided between the third conductor 4 and the outer dielectric layer 6.

The power and telecommunications cable, according to the invention, in the third embodiment, is a single-phase coaxial cable and comprises a multimode photonic-crystal optical fiber 1, and its conductors 2. 3, 4. 7 and 8 are of aluminum braid. For the remaining part, the cable is made as in the first embodiment.

List of designations

1 - optical fiber la - core lb - optical fiber jacket 1c - protective layer

- first conductor

- second conductor

- third conductor

- inner dielectric layer

- outer dielectric layer

- fourth conductor

- fifth conductor

SUBSTITUTE SHEET (RULE 26)