Patents by Inventor Jörg Präger
Jörg Präger has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10774765Abstract: A method is for starting a combustion engine having a pull-rope starter. A fuel/air mixture is fed to the engine via an intake channel. The mixture is ignited by a spark plug. The combustion drives the piston downward and drives a crankshaft rotationally. The fuel system has a fuel channel opening into the intake channel. An electric fuel valve is open in its currentless state and closes a fuel channel only when an operating voltage is applied. An electronic control unit actuates the fuel valve and triggers an ignition spark and is utilized by a generator to supply energy to the control unit, the fuel valve and the ignition device. To prevent excessive enriching of the fuel/air mixture during starting, the energy, which is generated at the beginning of the rotation of the crankshaft, is used to first close the fuel valve before the control unit triggers an ignition spark.Type: GrantFiled: July 5, 2018Date of Patent: September 15, 2020Assignee: Andreas Stihl AG & Co. KGInventors: Klaus Geyer, Martin Kiesner, Joerg Praeger, Steffen Bantle, David Fallscheer, Erik Ames
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Publication number: 20180313284Abstract: A method is for starting a combustion engine having a pull-rope starter. A fuel/air mixture is fed to the engine via an intake channel. The mixture is ignited by a spark plug. The combustion drives the piston downward and drives a crankshaft rotationally. The fuel system has a fuel channel opening into the intake channel. An electric fuel valve is open in its currentless state and closes a fuel channel only when an operating voltage is applied. An electronic control unit actuates the fuel valve and triggers an ignition spark and is utilized by a generator to supply energy to the control unit, the fuel valve and the ignition device. To prevent excessive enriching of the fuel/air mixture during starting, the energy, which is generated at the beginning of the rotation of the crankshaft, is used to first close the fuel valve before the control unit triggers an ignition spark.Type: ApplicationFiled: July 5, 2018Publication date: November 1, 2018Inventors: Klaus Geyer, Martin Kiesner, Joerg Praeger, Steffen Bantle, David Fallscheer, Erik Ames
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Patent number: 9423437Abstract: The invention relates to an arrangement for identifying a switching position of a switch (on an internal combustion engine in a handheld work apparatus. An energy source for supplying power to an inductive electrical load is provided, it being possible to connect the load to the energy source in order to be switched on and off via a controller. The switch is arranged in a voltage branch which is connected in parallel with the inductive load and in which a zener diode is also connected. The zener diode is activated or inactivated via the switch as a function of the switching position of the switch. The amplitude of the switch-off voltage, which is induced when the inductive load is disconnected, is limited by the zener diode, so that it is possible to read from the magnitude of the amplitude whether the switch is closed or open.Type: GrantFiled: July 29, 2013Date of Patent: August 23, 2016Assignee: Andreas Stihl AG & Co. KGInventors: Joerg Praeger, Franz Mandl, Robert Boeker
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Publication number: 20150047593Abstract: A method is for starting a combustion engine having a pull-rope starter. A fuel/air mixture is fed to the engine via an intake channel. The mixture is ignited by a spark plug. The combustion drives the piston downward and drives a crankshaft rotationally. The fuel system has a fuel channel opening into the intake channel. An electric fuel valve is open in its currentless state and closes a fuel channel only when an operating voltage is applied. An electronic control unit actuates the fuel valve and triggers an ignition spark and is utilized by a generator to supply energy to the control unit, the fuel valve and the ignition device. To prevent excessive enriching of the fuel/air mixture during starting, the energy, which is generated at the beginning of the rotation of the crankshaft, is used to first close the fuel valve before the control unit triggers an ignition spark.Type: ApplicationFiled: August 18, 2014Publication date: February 19, 2015Inventors: Klaus Geyer, Martin Kiesner, Joerg Praeger, Steffen Bantle, David Fallscheer, Erik Ames
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Patent number: 8914219Abstract: In a method for operating an internal combustion engine for adjusting a desired fuel/air mixture, wherein the rotary speed is determined by an operating curve based on a fuel/air mixture composition, wherein the operating curve has ascending and descending branches and a maximum, wherein a lambda value is smaller than 1 on the descending branch, it is first determined by statistic evaluation whether the operating point is on the ascending or descending branch. In a second method step, when the operating point is not on a desired branch of the operating curve desired as a starting point for a third method step, at least one operating parameter is changed until the operating point is positioned on the desired branch. In a third method step, the maximum of the operating curve is determined. Based on the determined maximum, the desired operating point of the internal combustion engine is then adjusted.Type: GrantFiled: July 2, 2010Date of Patent: December 16, 2014Assignee: Andreas Stihl AG & Co. KGInventors: Andreas Neubauer, Jörg Präger
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Patent number: 8833322Abstract: A portable work apparatus has a combustion engine for driving a work tool. An air/fuel mixture is supplied to the engine via a carburetor which is provided with an electrical heating element for heating to a given temperature. The heating element is connected to a switch via which electrical energy, which is provided by a generator driven by the engine, is supplied. When a given temperature is exceeded, the switch interrupts the energy supply. To achieve an exact temperature control, the ohmic resistance value of the heating element is stored in a memory in dependence on the temperature. The current flowing through the heating element and the voltage drop at the heating element are measured and the instantaneous resistance of the heating element is calculated therefrom. This calculated value is compared to the value stored in the memory to open or close the switch in dependence on the comparison.Type: GrantFiled: November 17, 2011Date of Patent: September 16, 2014Assignee: Andreas Stihl AG & Co. KGInventors: Heinrich Leufen, Jörg Präger, David Fallscheer, Rolf Walter, Michael Link
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Patent number: 8667955Abstract: A handheld work apparatus has a drive motor which drives a work tool and a generator. The work apparatus has a first electrical load and a connectable second electrical load. The generator provides the electrical power for the simultaneous operation of the two loads. The work apparatus has a control unit for controlling the power supplied to the first electrical load. In order to supply approximately the same power independent of voltage fluctuations, a voltage monitoring circuit is provided which, in a first operating state, sets a first signal sequence for operating the first load and, in a second operating state, sets a different second signal sequence for operating the first load. The mean power of the first signal sequence and that of the other second signal sequence are approximately equal.Type: GrantFiled: April 20, 2012Date of Patent: March 11, 2014Assignee: Andreas Stihl AG & Co. KGInventors: Heinrich Leufen, Jörg Präger, David Fallscheer
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Publication number: 20140028332Abstract: The invention relates to an arrangement for identifying a switching position of a switch (on an internal combustion engine in a handheld work apparatus. An energy source for supplying power to an inductive electrical load is provided, it being possible to connect the load to the energy source in order to be switched on and off via a controller. The switch is arranged in a voltage branch which is connected in parallel with the inductive load and in which a zener diode is also connected. The zener diode is activated or inactivated via the switch as a function of the switching position of the switch. The amplitude of the switch-off voltage, which is induced when the inductive load is disconnected, is limited by the zener diode, so that it is possible to read from the magnitude of the amplitude whether the switch is closed or open.Type: ApplicationFiled: July 29, 2013Publication date: January 30, 2014Applicant: Andreas Stihl AG & Co. KGInventors: Joerg Praeger, Franz Mandl, Robert Boeker
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Publication number: 20120266850Abstract: A handheld work apparatus has a drive motor which drives a work tool and a generator. The work apparatus has a first electrical load and a connectable second electrical load. The generator provides the electrical power for the simultaneous operation of the two loads. The work apparatus has a control unit for controlling the power supplied to the first electrical load. In order to supply approximately the same power independent of voltage fluctuations, a voltage monitoring circuit is provided which, in a first operating state, sets a first signal sequence for operating the first load and, in a second operating state, sets a different second signal sequence for operating the first load. The mean power of the first signal sequence and that of the other second signal sequence are approximately equal.Type: ApplicationFiled: April 20, 2012Publication date: October 25, 2012Inventors: Heinrich Leufen, Jörg Präger, David Fallscheer
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Publication number: 20120118254Abstract: A portable work apparatus has a combustion engine for driving a work tool. An air/fuel mixture is supplied to the engine via a carburetor which is provided with an electrical heating element for heating to a given temperature. The heating element is connected to a switch via which electrical energy, which is provided by a generator driven by the engine, is supplied. When a given temperature is exceeded, the switch interrupts the energy supply. To achieve an exact temperature control, the ohmic resistance value of the heating element is stored in a memory in dependence on the temperature. The current flowing through the heating element and the voltage drop at the heating element are measured and the instantaneous resistance of the heating element is calculated therefrom. This calculated value is compared to the value stored in the memory to open or close the switch in dependence on the comparison.Type: ApplicationFiled: November 17, 2011Publication date: May 17, 2012Inventors: Heinrich Leufen, Jörg Präger, David Fallscheer, Rolf Walter, Michael Link
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Publication number: 20110004395Abstract: In a method for operating an internal combustion engine for adjusting a desired fuel/air mixture, wherein the rotary speed is determined by an operating curve based on a fuel/air mixture composition, wherein the operating curve has ascending and descending branches and a maximum, wherein a lambda value is smaller than 1 on the descending branch, it is first determined by statistic evaluation whether the operating point is on the ascending or descending branch. In a second method step, when the operating point is not on a desired branch of the operating curve desired as a starting point for a third method step, at least one operating parameter is changed until the operating point is positioned on the desired branch. In a third method step, the maximum of the operating curve is determined. Based on the determined maximum, the desired operating point of the internal combustion engine is then adjusted.Type: ApplicationFiled: July 2, 2010Publication date: January 6, 2011Applicant: ANDREAS STIHL AG & CO. KGInventors: Andreas Neubauer, Jörg Präger