Abstract: A method for bending profiles, wherein the profiles have a profile web and bent or angled profile legs at lateral ends of the profile web, wherein the profile is bent or formed parallel to and in the plane of the profile web and the height of the profile web between the profile legs varies over the length of the profile. The profile is formed with a roll arrangement that has at least one supporting roll, one bending roll, and one forming roll positioned one after the other in the movement direction, wherein the supporting roll, the bending roll, and the forming roll rest against the profile or profile legs in lateral edge regions, and through the adjustment of the distance between the bending roll and the forming roll perpendicular to the movement direction of the profile, it is possible to adjust the bending radius of a profile.

Abstract: A two-stroke engine possesses a cylinder, in the cylinder bore of which a combustion chamber is formed. The combustion chamber is bounded by a reciprocating piston, which drives a crankshaft rotatably mounted in a crankcase. A crankcase interior is fluidically connected to the combustion chamber across at least one transfer channel in at least one position of the piston. The at least one transfer channel emerges with a discharge opening in the crankcase interior and with at least one transfer window on the cylinder bore. It is proposed that all transfer channels have an average length as measured from the discharge opening to the transfer window, the average length being at least 1.5 in relation to the stroke, and that the volume of the crankcase interior including all transfer channels is at most 3.1 in relation to the piston displacement.

Abstract: A two-stroke engine possesses a cylinder, in the cylinder bore of which a combustion chamber is formed. The combustion chamber is bounded by a reciprocating piston, which drives a crankshaft rotatably mounted in a crankcase. A crankcase interior is fluidically connected to the combustion chamber across at least one transfer channel in at least one position of the piston. The at least one transfer channel emerges with a discharge opening in the crankcase interior and with at least one transfer window on the cylinder bore. It is proposed that all transfer channels have an average length as measured from the discharge opening to the transfer window, the average length being at least 1.5 in relation to the stroke, and that the volume of the crankcase interior including all transfer channels is at most 3.1 in relation to the piston displacement.

Abstract: A carburetor has a carburetor body wherein an intake channel is formed. A throttle flap is pivotably mounted by a throttle shaft in the carburetor body for controlling the free flow cross-section of the intake channel. The intake channel has a first longitudinal center axis in the region of the throttle shaft. The throttle flap has first and second end positions, wherein the throttle flap opens a larger flow cross-section of the intake channel in the second end position than in the first end position. A partition wall section, on which the throttle flap lies in the second end position, is arranged upstream of the throttle shaft. A choke flap is upstream of the partition wall section and is pivotable between first and second end positions. In their second end positions, the throttle flap and the choke flap overlap in the direction of the first longitudinal center axis.

Abstract: A fuel supply device has a base body, in which an intake channel section is formed. At least one adjustable throttle element for controlling the free flow cross section of the intake channel section is provided. At least one fuel opening opens into the intake channel section. A partition wall section is arranged in the intake channel section upstream of the throttle element. The partition wall section and the throttle element divide, in a completely open position of the throttle element, the intake channel section upstream of the throttle element into a mixture channel, into which the fuel opening feeds fuel, and an air channel. In order to improve the cooling of the fuel supply device, the partition wall section has at least one element for increasing the surface area within the mixture channel.

Abstract: A carburetor has a carburetor body wherein an intake channel is formed. A throttle flap is pivotably mounted by a throttle shaft in the carburetor body for controlling the free flow cross-section of the intake channel. The intake channel has a first longitudinal center axis in the region of the throttle shaft. The throttle flap has first and second end positions, wherein the throttle flap opens a larger flow cross-section of the intake channel in the second end position than in the first end position. A partition wall section, on which the throttle flap lies in the second end position, is arranged upstream of the throttle shaft. A choke flap is upstream of the partition wall section and is pivotable between first and second end positions. In their second end positions, the throttle flap and the choke flap overlap in the direction of the first longitudinal center axis.

Abstract: A motor chain saw has a first driven sprocket wheel driving a saw chain lubricated via a supply pump driven by first and second drive wheel, wherein the second drive wheel is connected to the first sprocket wheel. A drive element with coupling section is connected to the first sprocket wheel and the second drive wheel is formed on the drive element. A second sprocket wheel can be used in place of the first sprocket wheel. The first and second sprocket wheels have different geometries. The coupling section has first and second followers correlated with follower surfaces of the first and second sprocket wheels. The coupling section contacts with first followers the follower surfaces of the first sprocket wheel or with second followers the follower surfaces of the second sprocket wheel when used in place of the first sprocket wheel.

Abstract: A transformerless inverter that serves to feed electricity from a DC current source into an AC power grid, has an inverter bridge and a DC/DC converter connected upstream of the inverter bridge. The DC/DC converter converts an input DC voltage that is present between two input lines of the inverter into a DC link voltage present between two input lines of the inverter bridge. The inverter bridge converts the DC link voltage present at the input lines thereof into an output AC voltage. The DC/DC converter includes at least one resonant circuit that has a resonance inductance and a resonance capacitance and is connected on its input side via at least two clocked switches to one of the two input lines of the inverter or an intermediate potential line carrying a potential in between. The input lines of the inverter and the input lines of the inverter bridge are galvanically isolated from one another by a capacitive method.

Abstract: A two-stroke engine (1) includes a combustion chamber (3) which is defined by a piston (5, 44) which is mounted in the cylinder (2) to reciprocate. The piston (5, 44) has a first control surface (62) which controls an outlet (9) out of the combustion chamber (3) and two second control surfaces (63) for the transfer windows (11, 13) of at least one transfer channel (10, 12). At least two transfer windows (11, 13) are arranged on opposite sides of the cylinder bore (60). At least a first recess is provided on the piston skirt (36) which extends in the peripheral area between the two second control surfaces (63) and which is separated from the transfer window (11, 13) via a section of the piston skirt (36) in every position of the piston (5, 44).

Abstract: A coupling device actuated by centrifugal force has a holder and at least one flyweight supported on the holder so as to be moveable in a radial direction relative to an axis of rotation about which the coupling device is rotatable. The flyweight is movable between an inner radial position and an outer radial position. At least one spring acting on the flyweight is provided that forces the flyweight into the inner radial position. At least one securing element secures at least one component of the coupling device in an axial direction of the axis of rotation. The securing element is monolithically formed on the flyweight.

Abstract: A protection system configured to couple between a generator that has a number of partial strings and an inverter includes a control device, and a series-connection switching device configured to selectively connect the partial strings together in series. The system also includes a parallel-connection switching device configured to selectively connect the partial strings together in parallel, wherein the series-connection switching device is actuated by the control device such that it interrupts the series connection of the partial strings in case of a hazard, and the parallel-connection switching device is actuated by the control device such that it connects the partial strings together in parallel in case of a hazard.

Abstract: A motor chain saw has a first driven sprocket wheel driving a saw chain lubricated via a supply pump driven by first and second drive wheel, wherein the second drive wheel is connected to the first sprocket wheel. A drive element with coupling section is connected to the first sprocket wheel and the second drive wheel is formed on the drive element. A second sprocket wheel can be used in place of the first sprocket wheel. The first and second sprocket wheels have different geometries. The coupling section has first and second followers correlated with follower surfaces of the first and second sprocket wheels. The coupling section contacts with first followers the follower surfaces of the first sprocket wheel or with second followers the follower surfaces of the second sprocket wheel when used in place of the first sprocket wheel.

Abstract: A solar power plant includes at least one photovoltaic module for generating power to be fed in a multi-phase grid. At least one inverter is provided for converting a direct voltage generated by the at least one photovoltaic module into an alternating mains voltage. A mains transformer is coupled to receive the alternating mains voltage from the inverter. The inverter is coupled to a primary side of the mains transformer. A direct voltage source coupled between an output of the at least one inverter and an input of the mains transformer such that a potential of the at least one photovoltaic module is displaced and that a bias voltage is set which is different from zero volts.

Abstract: The object of the invention is a high-efficiency DC/DC converter, in particular for photovoltaic plants, incorporating a transformerless DC/DC converter operated in the resonant mode of operation for converting a unipolar direct input voltage with an associated positive pole (+) and with a negative pole (?). There is imposed a resonance circuit incorporating at least one resonance inductance and at least one resonance capacitance, each resonance capacitance being connected to a respective one of the rectifier circuit arrangements in such a manner that the bipolar direct output voltage is provided, a voltage boosting circuit arrangement being connected to each resonance capacitance and to the rectifier circuit arrangement.

Abstract: A solar power plant includes at least one photovoltaic module for generating power to be fed in a multi-phase grid. At least one inverter is provided for converting a direct voltage generated by the at least one photovoltaic module into an alternating mains voltage. A mains transformer is coupled to receive the alternating mains voltage from the inverter. The inverter is coupled to a primary side of the mains transformer. A direct voltage source coupled between an output of the at least one inverter and an input of the mains transformer such that a potential of the at least one photovoltaic module is displaced and that a bias voltage is set which is different from zero volts.

Abstract: A solar power plant with a plurality of photovoltaic modules for generating a power to be fed in a multi-phase grid, several photovoltaic strings, which are allocated to different phases, being connected to a primary side of a mains transformer and at least one inverter for converting the direct voltage generated by the photovoltaic modules into an alternating mains voltage conforming to the grid being provided and said mains transformer being provided with a neutral conductor and with a grounded terminal, is intended to be improved in such a manner that the life of the photovoltaic modules, in particular in case of thin-film modules, is increased, allowing for high conversion efficiency of the inverters at low wiring costs. This is achieved in that an additional direct voltage source is inserted between the neutral conductor and ground in such a manner that the potential of the photovoltaic strings is displaced and that a bias voltage is set, which is different from zero volt.

Abstract: A transformerless inverter that serves to feed electricity from a DC current source into an AC power grid, has an inverter bridge and a DC/DC converter connected upstream of the inverter bridge. The DC/DC converter converts an input DC voltage that is present between two input lines of the inverter into a DC link voltage present between two input lines of the inverter bridge. The inverter bridge converts the DC link voltage present at the input lines thereof into an output AC voltage. The DC/DC converter includes at least one resonant circuit that has a resonance inductance and a resonance capacitance and is connected on its input side via at least two clocked switches to one of the two input lines of the inverter or an intermediate potential line carrying a potential in between. The input lines of the inverter and the input lines of the inverter bridge are galvanically isolated from one another by a capacitive method.

Abstract: An inverter (1) for a grounded direct voltage source, in particular for a photovoltaic generator (2), a battery or a fuel cell, for converting the direct voltage into an alternative voltage with a DC-DC converter (3) and a pulse inverter that is supplied by said DC-DC converter (3), said DC-DC converter (3) being configured to be an oscillating circuit inverter and comprising a series resonant oscillating circuit, said DC-DC converter (3), which is configured to be an oscillating circuit inverter, being configured to be a series-compensated oscillating circuit inverter with a choke (L1) and a series-mounted capacitor array consisting of two or several oscillating circuit capacitors, a rectifier bridge branch including 2 diodes (D3, D4; D5, D6, . . .

Abstract: A two-stroke engine (1) includes a combustion chamber (3) which is defined by a piston (5, 44) which is mounted in the cylinder (2) to reciprocate. The piston (5, 44) has a first control surface (62) which controls an outlet (9) out of the combustion chamber (3) and two second control surfaces (63) for the transfer windows (11, 13) of at least one transfer channel (10, 12). At least two transfer windows (11, 13) are arranged on opposite sides of the cylinder bore (60). At least a first recess is provided on the piston skirt (36) which extends in the peripheral area between the two second control surfaces (63) and which is separated from the transfer window (11, 13) via a section of the piston skirt (36) in every position of the piston (5, 44).

Abstract: A method of converting a direct voltage generated by a decentralized power supply system into three-phase alternating voltage by means of a plurality of single-phase inverters (WR1-WR3), said alternating voltage being provided for supplying an electric mains, is intended to avoid inadmissible load unbalances using single-phase inverters. This is achieved in that, upon failure of one inverter (WR1-WR3), an asymmetrical power supply distribution is reduced by limiting the output of the other inverters. The method makes it possible to simplify three-phase voltage monitoring.