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).

  • Patent number: 10520134
    Abstract: 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: Grant
    Filed: March 21, 2017
    Date of Patent: December 31, 2019
    Assignee: Andreas Stihl AG & Co. KG
    Inventors: Joachim Kolb, David Kraetzig
  • Publication number: 20170268723
    Abstract: 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: Application
    Filed: March 21, 2017
    Publication date: September 21, 2017
    Inventors: Joachim Kolb, David Kraetzig
  • Patent number: 9379596
    Abstract: 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: Grant
    Filed: April 9, 2013
    Date of Patent: June 28, 2016
    Assignee: Andreas Stihl AG & Co. KG
    Inventor: David Kraetzig
  • Patent number: 9041320
    Abstract: 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: Grant
    Filed: July 8, 2013
    Date of Patent: May 26, 2015
    Assignee: Andreas Stihl AG & Co. KG
    Inventors: Arne Untermann, Markus Maier, Ante Hamersmit, Christian Renz, Johannes Menzel, Ina Schneider, Jochen Luz, Jens Kloeker, Harald Mang, David Hampe, David Kraetzig
  • Publication number: 20140007435
    Abstract: 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: Application
    Filed: July 8, 2013
    Publication date: January 9, 2014
    Inventors: Arne Untermann, Markus Maier, Ante Hamersmit, Christian Renz, Johannes Menzel, Ina Schneider, Jochen Luz, Jens Kloeker, Harald Mang, David Hampe, David Kraetzig
  • Publication number: 20130270933
    Abstract: 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: Application
    Filed: April 9, 2013
    Publication date: October 17, 2013
    Applicant: Andreas Stihl AG & Co. KG
    Inventor: David Kraetzig