Patents by Inventor Ralf Cornelsen

Ralf Cornelsen 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: 10941786
    Abstract: A handheld work apparatus has a blower wheel. The blower wheel is held via a nut on the shaft in a manner locked against rotation by frictional force. A thread moment of friction is transmittable between the nut and the shaft via a thread section. A first moment of friction is transmittable between the nut and the blower wheel via a first friction contact surface. The first friction contact surface is configured such that, at a minimum tightening torque of the nut, the first moment of friction is greater than the thread moment of friction. As a result, during the operation of the work apparatus when there is a relative movement between the blower wheel and the shaft, the blower wheel moves the nut along therewith. The nut retensions the blower wheel against the shaft. The second friction contact surface runs conically with respect to the rotational axis.
    Type: Grant
    Filed: September 14, 2018
    Date of Patent: March 9, 2021
    Assignee: Andreas Stihl AG & Co. KG
    Inventors: Gerd Densborn, Harald Schliemann, Ralf Cornelsen, Wolfgang Weissert
  • Publication number: 20190085861
    Abstract: A handheld work apparatus has a blower wheel. The blower wheel is held via a nut on the shaft in a manner locked against rotation by frictional force. A thread moment of friction is transmittable between the nut and the shaft via a thread section. A first moment of friction is transmittable between the nut and the blower wheel via a first friction contact surface. The first friction contact surface is configured such that, at a minimum tightening torque of the nut, the first moment of friction is greater than the thread moment of friction. As a result, during the operation of the work apparatus when there is a relative movement between the blower wheel and the shaft, the blower wheel moves the nut along therewith. The nut retensions the blower wheel against the shaft. The second friction contact surface runs conically with respect to the rotational axis.
    Type: Application
    Filed: September 14, 2018
    Publication date: March 21, 2019
    Inventors: Gerd Densborn, Harald Schliemann, Ralf Cornelsen, Wolfgang Weissert
  • Patent number: 9624993
    Abstract: A hand-held work implement having a tool has a braking device for the tool that includes a brake band which wraps around a brake drum. The brake band and the brake drum undergo friction as they move relative to one another during braking. At least one of the band or drum comprises an austenitic steel, a duplex steel, super duplex steel, a nickel-base alloy or a cobalt-base alloy and has a base body and a marginal layer. The hardness of the marginal layer is approximately 150% to approximately 600% of the hardness of the base body and the carbide proportion in the marginal layer is less than approximately 0.5% by weight. A process for production of the foregoing includes diffusing carbon and/or nitrogen into a marginal layer at a temperature of less than 500° C.
    Type: Grant
    Filed: March 27, 2014
    Date of Patent: April 18, 2017
    Assignee: ANDREAS STIHL AG & CO. KG
    Inventors: Norbert Apfel, Manfred Schumacher, Ralf Cornelsen
  • Publication number: 20140291080
    Abstract: A hand-held work implement having a tool has a braking device for the tool that includes a brake band which wraps around a brake drum. The brake band and the brake drum undergo friction as they move relative to one another during braking. At least one of the band or drum comprises an austenitic steel, a duplex steel, super duplex steel, a nickel-base alloy or a cobalt-base alloy and has a base body and a marginal layer. The hardness of the marginal layer is approximately 150% to approximately 600% of the hardness of the base body and the carbide proportion in the marginal layer is less than approximately 0.5% by weight. A process for production of the foregoing includes diffusing carbon and/or nitrogen into a marginal layer at a temperature of less than 500° C.
    Type: Application
    Filed: March 27, 2014
    Publication date: October 2, 2014
    Applicant: ANDREAS STIHL AG & CO. KG
    Inventors: Norbert Apfel, Manfred Schumacher, Ralf Cornelsen