Abstract: The present invention relates to an arrangement and electronic navigational control system for a self-propelling device (5), preferably a lawn-mowing robot. The system comprises at least one navigational control system (3) connected to at least one signal generator (1) and a sensing unit arranged at the self-propelling device (5). The sensing unit senses at least one, in the air medium propagating, time and space varying magnetic field, at least transmitted via the navigational control station (3) and in turn retransmits at least one signal processed by the unit to at least one driving source which contributes to the device's movements across the surface. The system comprises means by which the signal generator (1) sends a current through the navigational control station (3), the current generating the time and space varying magnetic field, whereby the sensing unit comprises means by which the device (5) is manoeuvred based on the properties of the sensed magnetic field.

Abstract: The present invention relates to a method and an electronic search system for operating an automatic device, preferably an automatic lawnmower. The system comprises at least one first electrical cable (1, 4, 5, 6) connected to at least one first signal generator (3, 7, 8) and at least one sensing system arranged on said device. Said sensing system detects at least one magnetic field being transmitted via said cable (1, 4, 5, 6) and propagating through the air, the sensing system transmitting a processed signal to at least one driving means which contributes to the movements of said device in relation to a surface. Said search system comprises means by which the first signal generator (3, 7, 8) of the present invention transmits a current through said first cable (3, 7, 8), said current during a part of time being is in a state of rest where it is substantially constant, said state periodically being interrupted by at least one first characteristic current pulse.

Abstract: A system includes a docking station, for location on a surface to be worked, and a self-propelled working tool. The station has a primary transmission part. The tool has a body, a surface-engaging wheel, and a secondary transmission part. The station and the tool can establish contact with each other and the tool can drive up to the station and achieve a docking position wherein the transmission parts contact and cooperate. In one aspect, the secondary transmission part is located on an upper portion of the body. In another aspect, the station includes a part spaced upwardly away from the surface, with the primary transmission part located thereon and directed downwardly. In another aspect, a portion of the body is located beneath a portion of the part upon which the primary part is located and the wheel remains engaged with the surface when in the docking position.

Abstract: A system includes a docking station, for location on a surface to be worked, and a self-propelled working tool. The station has a primary transmission part. The tool has a body, a surface-engaging wheel, and a secondary transmission part. The station and the tool can establish contact with each other and the tool can drive up to the station and achieve a docking position wherein the transmission parts contact and cooperate. In one aspect, the secondary transmission part is located on an upper portion of the body. In another aspect, the station includes a part spaced upwardly away from the surface, with the primary transmission part located thereon and directed downwardly. In another aspect, a portion of the body is located beneath a portion of the part upon which the primary part is located and the wheel remains engaged with the surface when in the docking position.

Abstract: A docking system (1) which essentially comprises at least one docking station (2) for at least one self-propelled working tool (3), and includes the working tool (3) itself, preferably intended for attendance of ground or floor, such as grass-cutting, moss-scratching, watering, vacuum-cleaning, polishing etc. The docking station and the tool can by way of emitted signals establish contact with each other, so that the tool can drive up to the docking station, and the docking station is provided with at least one first transmission part (5, 6; 5′, 6′) for transmission of energy and/or information between the docking station and the working tool, which is provided with at least one co-operating second transmission part (7, 8).

Abstract: A search system for a tool. A border cable separates inner and outer areas. A generator feeds the border cable with current, whose magnetic field affects a sensing unit on the tool, and the sensing unit emits signals to a control unit that directs the tool's motion. The current contains at least two components of different frequency. A search cable is placed within the inner area so that it separates a search area, and is fed by a signal generator with an adapted current (e.g., the current direction alternates to be either in phase or out of phase in relation to the current direction in the border cable) so that the magnetic fields in the different areas provide at least three patterns. Accordingly, the control unit can separate the inner, outer, and search areas.

Abstract: A solenoid (1) comprising at least two stationary coils (2, 3), which are located axially beside each other and are current supplied at the same time, and at least one magnetically active element (4, 5), such as a permanent magnet or a soft iron part. The solenoid contains one inner and one outer magnetically active element (4, 5), of which at least one is composed of an essentially axially magnetized permanent magnet (4, 5). The coils are located between the elements (4, 5), so that they surround the inner element (4), and are arranged with mutually different current direction, and the coils and the elements (4, 5) are arranged around an essentially mutual axis center line (6), so that a magnetic field is obtained between the elements (4, 5) and this crosses the current supplied coils' (2, 3) wire essentially perpendicularly and gives rise to an axial power action between the coils and the elements, and at least one of the elements is axially movable.

Abstract: An electronic bordering system for a working tool in which a border cable is placed above, under or on ground or floor, so that it separates an inner area within the border cable from an outer area. The working tool is preferably intended for attendance of ground or floor. A signal generator feeds the border cable with current, whose magnetic field affects at least one sensing unit located on the working tool, so that the sensing unit emits signals to a control unit, which in cooperation with an engine control, or a signal system for a driver, and at least one driving source directs the tool's movement in order to prevent it from remoting from the inner area. The signal generator feeds the border cable with current containing at least two alternating-current components of different frequency, and the components are lying in a known relation of time to each other.

Abstract: A method and a device of controlling the amount of fuel delivered to a combustion engine (1), e.g. of two-stroke or four-stroke type, wherein the fuel is supplied through an intake passage (2) intended to deliver air (3) and fuel (4) to the cylinder (5), said intake passage being opened and closed by a piston (6) or by a special valve (7). The fuel supply to the intake passage (2) is effected upstream from the piston (6) or the valve (7) and in response to the opening and closing of the intake passage (2) varying flow speeds and pressures are produced in the passage and the fuel supply system (8) is of a kind the supply amount of which is substantially affected by this variation, such as a carburetor (9) or a low-pressure injection system (10).