Patents by Inventor David Kraetzig
David Kraetzig 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: 10520134Abstract: A handheld work apparatus has a device for starting an electric drive motor via an actuating element which can be displaced in a handle counter to an actuating force and acts on a transmission element. The transmission element is shiftable from a rest position into an operating range, wherein the transmission element actuates a switching element and starts the motor. For shifting from the rest position into an end position, a shift force is applied. The shift force forms at least a portion of the actuating force. To keep the actuating force low after the motor is switched on, the displacement path of the transmission element is divided into a first segment and a second segment which includes the operating range. The shift force to be applied to the transmission element rises on the first segment of the path and, after a maximum, decreases on the second segment.Type: GrantFiled: March 21, 2017Date of Patent: December 31, 2019Assignee: Andreas Stihl AG & Co. KGInventors: Joachim Kolb, David Kraetzig
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Publication number: 20170268723Abstract: A handheld work apparatus has a device for starting an electric drive motor via an actuating element which can be displaced in a handle counter to an actuating force and acts on a transmission element. The transmission element is shiftable from a rest position into an operating range, wherein the transmission element actuates a switching element and starts the motor. For shifting from the rest position into an end position, a shift force is applied. The shift force forms at least a portion of the actuating force. To keep the actuating force low after the motor is switched on, the displacement path of the transmission element is divided into a first segment and a second segment which includes the operating range. The shift force to be applied to the transmission element rises on the first segment of the path and, after a maximum, decreases on the second segment.Type: ApplicationFiled: March 21, 2017Publication date: September 21, 2017Inventors: Joachim Kolb, David Kraetzig
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Patent number: 9379596Abstract: A work apparatus has a tool which is driven in rotation by a drive motor via a transmission. The drive motor is an electric motor which has a commutator and brushes. The drive motor is arranged in a motor housing and drives an impeller wheel which conveys a cooling airflow for the drive motor. Simple and effective lubrication of the transmission is achieved with the cooling airflow flowing past the commutator and brushes and the transmission is arranged downstream of the commutator in the cooling airflow. The motor housing is formed in a manner closed toward the transmission housing on that end side that faces the transmission housing and is connected to the transmission housing via a flow connection.Type: GrantFiled: April 9, 2013Date of Patent: June 28, 2016Assignee: Andreas Stihl AG & Co. KGInventor: David Kraetzig
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Patent number: 9220201Abstract: A hand-held power tool has a power tool housing made at least partially of plastic material. A drive motor is arranged in the power tool housing and a drive shaft driven connected to the drive motor is provided. A tool member is connected to the drive shaft and driven by the drive motor through the drive shaft. A first bearing rotatably supports the drive shaft relative to the power tool housing. An intermediate element supports the first bearing relative to the power tool housing. The intermediate element is arranged in a receptacle of the power tool housing and is supported on a support surface relative to the bottom of the receptacle. The support surface is less than approximately 50% of an imaginary circular ring surface defined between an outer circumference of the first bearing and the circumcircle of the receptacle.Type: GrantFiled: March 9, 2012Date of Patent: December 29, 2015Assignee: Andreas Stihl AG & Co. KGInventors: David Krätzig, Harald Mang, Arne Untermann, Steffen Drexler
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Patent number: 9041320Abstract: The invention relates to a portable work apparatus having a housing and a work tool which is driven by an electric motor via a gear assembly. A flywheel which rotates about a rotational axis is arranged in the drive train between the electric motor and the gear assembly, which flywheel is connected fixedly to an output shaft so as to rotate with it, which output shaft protrudes into a gear assembly space and has a drive pinion. The output, shaft and the flywheel are mounted in the housing by two bearing locations, the rotational axis of the flywheel and a motor shaft of the electric motor lying coaxially with respect to one another, and the motor shaft of the electric motor being connected fixedly to the flywheel so as to rotate with it. The electric motor is fixed in the housing exclusively via a torque support.Type: GrantFiled: July 8, 2013Date of Patent: May 26, 2015Assignee: Andreas Stihl AG & Co. KGInventors: Arne Untermann, Markus Maier, Ante Hamersmit, Christian Renz, Johannes Menzel, Ina Schneider, Jochen Luz, Jens Kloeker, Harald Mang, David Hampe, David Kraetzig
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Patent number: 8813369Abstract: The invention relates to hand-held hedge shears with an in particular electric driving motor. The hedge shears comprises a gripping housing with a rear handle, wherein a gripping part of the rear handle is rotatable about the longitudinal axis thereof and is lockable in the rotational position thereof by means of a locking element. An operating switch lever for the driving motor is arranged on the rotatable gripping part, wherein the operating switch lever acts by means of a sliding element and a transmission element on a switch unit for the rotational speed position of the driving motor. The sliding element is guided on the locking element in a manner sliding in the direction of the longitudinal axis.Type: GrantFiled: December 14, 2011Date of Patent: August 26, 2014Assignee: Andreas Stihl AG & Co. KGInventor: David Krätzig
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Publication number: 20140007435Abstract: The invention relates to a portable work apparatus having a housing and a work tool which is driven by an electric motor via a gear assembly. A flywheel which rotates about a rotational axis is arranged in the drive train between the electric motor and the gear assembly, which flywheel is connected fixedly to an output shaft so as to rotate with it, which output shaft protrudes into a gear assembly space and has a drive pinion. The output, shaft and the flywheel are mounted in the housing by two bearing locations, the rotational axis of the flywheel and a motor shaft of the electric motor lying coaxially with respect to one another, and the motor shaft of the electric motor being connected fixedly to the flywheel so as to rotate with it. The electric motor is fixed in the housing exclusively via a torque support.Type: ApplicationFiled: July 8, 2013Publication date: January 9, 2014Inventors: Arne Untermann, Markus Maier, Ante Hamersmit, Christian Renz, Johannes Menzel, Ina Schneider, Jochen Luz, Jens Kloeker, Harald Mang, David Hampe, David Kraetzig
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Publication number: 20130270933Abstract: A work apparatus has a tool which is driven in rotation by a drive motor via a transmission. The drive motor is an electric motor which has a commutator and brushes. The drive motor is arranged in a motor housing and drives an impeller wheel which conveys a cooling airflow for the drive motor. Simple and effective lubrication of the transmission is achieved with the cooling airflow flowing past the commutator and brushes and the transmission is arranged downstream of the commutator in the cooling airflow. The motor housing is formed in a manner closed toward the transmission housing on that end side that faces the transmission housing and is connected to the transmission housing via a flow connection.Type: ApplicationFiled: April 9, 2013Publication date: October 17, 2013Applicant: Andreas Stihl AG & Co. KGInventor: David Kraetzig
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Publication number: 20120234572Abstract: A hand-held power tool has a power tool housing made at least partially of plastic material. A drive motor is arranged in the power tool housing and a drive shaft driven connected to the drive motor is provided. A tool member is connected to the drive shaft and driven by the drive motor through the drive shaft. A first bearing rotatably supports the drive shaft relative to the power tool housing. An intermediate element supports the first bearing relative to the power tool housing. The intermediate element is arranged in a receptacle of the power tool housing and is supported on a support surface relative to the bottom of the receptacle. The support surface is less than approximately 50% of an imaginary circular ring surface defined between an outer circumference of the first bearing and the circumcircle of the receptacle.Type: ApplicationFiled: March 9, 2012Publication date: September 20, 2012Applicant: ANDREAS STIHL AG & CO. KGInventors: David Krätzig, Harald Mang, Arne Untermann, Steffen Drexler
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Publication number: 20120151779Abstract: The invention relates to hand-held hedge shears with an in particular electric driving motor. The hedge shears comprises a gripping housing with a rear handle, wherein a gripping part of the rear handle is rotatable about the longitudinal axis thereof and is lockable in the rotational position thereof by means of a locking element. An operating switch lever for the driving motor is arranged on the rotatable gripping part, wherein the operating switch lever acts by means of a sliding element and a transmission element on a switch unit for the rotational speed position of the driving motor. The sliding element is guided on the locking element in a manner sliding in the direction of the longitudinal axis.Type: ApplicationFiled: December 14, 2011Publication date: June 21, 2012Inventor: David Krätzig