Patents by Inventor Hugo Burkhart

Hugo Burkhart 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: 8306716
    Abstract: A method for controlling a desired speed of a vehicle having a retarder operating in an overrun condition is proposed, such that the desired speed of the vehicle is controlled by a continuously adjustable retarder braking system and/or an engine braking control system.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: November 6, 2012
    Assignee: ZF Friedrichshafen AG
    Inventors: Hugo Burkhart, Bernd Aumann
  • Patent number: 7979188
    Abstract: A method for activating and deactivating the four-wheel drive of a service or a working vehicle not having interaxle differential locks. According to the method, the activation and deactivation of the four-wheel drive is derived from at least one of the following parameters, namely, the driving and load conditions of the vehicle (1), the vehicle speed and the output torque of the gearbox.
    Type: Grant
    Filed: April 29, 2006
    Date of Patent: July 12, 2011
    Assignee: ZF Friedrichshafen AG
    Inventors: Hugo Burkhart, Bernd Aumann
  • Patent number: 7613559
    Abstract: A method for automatically actuating longitudinal blocks in four-wheel vehicles, particularly in working machines and service vehicles. The longitudinal blocks are always open when driving situations occur in which the blocking effect is absolutely unnecessary. The longitudinal blocks are closed in all other situations.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: November 3, 2009
    Assignee: ZF Friedrichshafen AG
    Inventors: Hugo Burkhart, Bernd Aumann
  • Patent number: 7454991
    Abstract: A shiftable multispeed reverse transmission having one input shaft (1) and a plurality of countershafts (2, 3, 4, 5, 6, 7) and one output shaft (8). One of gears and/or idle gears being situated upon the countershafts (2, 3, 4, 5, 6, 7) for non-rotatably connection with the countershafts, via shiftable clutches, for gear and direction change. The reduction ratios being generated by spur pinion stages and at least one shiftable planetary stage (P).
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: November 25, 2008
    Assignee: ZF Friedrichshafen AG
    Inventors: Gerhard Buck, Wolfgang Rebholz, Siegfried Stützle, Michael Riedhammer, Hugo Burkhart, Michael Herlitzek, Jürgen Legner, Jochen Schneider, Michael Thielmann, Roland Fischer
  • Publication number: 20080262693
    Abstract: A method for controlling the desired speed in overrun condition for a vehicle comprising a retarder is proposed, such that the desired speed is controlled by a continuously adjustable retarder braking and/or engine braking control system.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 23, 2008
    Applicant: ZF Friedrichschafen AG
    Inventors: Hugo BURKHART, Bernd Aumann
  • Publication number: 20080195288
    Abstract: The invention relates to a method for activating and deactivating the four-wheel drive of service and working vehicles without interaxle differential locks. According to said method, said activation and deactivation of the four-wheel drive is derived from the driving and load conditions of the vehicle (1), the vehicle speed and/or gearbox output torque being used as parameters.
    Type: Application
    Filed: April 29, 2006
    Publication date: August 14, 2008
    Applicant: ZF Friedrichshafen AG
    Inventors: Hugo Burkhart, Bernd Aumann
  • Publication number: 20080065303
    Abstract: A method for the activation of differential locks for vehicles, especially for such vehicles as may be used in construction work and field operations. The differential locks are always open, if the driving situation is such that a blocking operation is assuredly not required and, conversely in all other situations, the differential locks are closed.
    Type: Application
    Filed: June 21, 2005
    Publication date: March 13, 2008
    Applicant: ZF Friedrichshafen AG
    Inventors: Hugo Burkhart, Bernd Aumann, Udo Hiller
  • Publication number: 20070233350
    Abstract: A method for automatically actuating longitudinal blocks in four-wheel vehicles, particularly in working machines and service vehicles. The longitudinal blocks are always open when driving situations occur in which the blocking effect is absolutely unnecessary. The longitudinal blocks are closed in all other situations.
    Type: Application
    Filed: June 16, 2005
    Publication date: October 4, 2007
    Applicant: ZF FRIEDRICHSHAFEN AG
    Inventors: Hugo Burkhart, Bernd Aumann
  • Publication number: 20070068294
    Abstract: A shiftable multispeed reverse transmission having one input shaft (1) and a plurality of countershafts (2, 3, 4, 5, 6, 7) and one output shaft (8). One of gears and/or idle gears being situated upon the countershafts (2, 3, 4, 5, 6, 7) for non-rotatably connection with the countershafts, via shiftable clutches, for gear and direction change. The reduction ratios being generated by spur pinion stages and at least one shiftable planetary stage (P).
    Type: Application
    Filed: December 14, 2004
    Publication date: March 29, 2007
    Inventors: Gerhard Buck, Wolfgang Rebholz, Siegfried Stutzle, Michael Riedhammer, Hugo Burkhart, Michael Herlitzek, Jurgen Legner, Jochen Schneider, Michael Thielmann, Roland Fischer
  • Patent number: 7073645
    Abstract: A control of a drive train for a wheel loader having one pressure-medium actuated brake and one transmission operated via a torque converter and at least one forward and/or reverse gear respectively actuated via a power shift clutch and one power take off wherein, when a predetermined value of the power delivered by the transmission to the power take off is exceeded, the pressure of the engaged power shift clutch for the forward or reverse gear is reduced to a residual level.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: July 11, 2006
    Assignee: ZF Friedrichshafen AG
    Inventor: Hugo Burkhart
  • Publication number: 20050103595
    Abstract: A control of a drive train for a wheel loader having one pressure-medium actuated brake and one transmission operated via a torque converter and at least one forward and/or reverse gear respectively actuated via a power shift clutch and one power take off wherein, when a predetermined value of the power delivered by the transmission to the power take off is exceeded, the pressure of the engaged power shift clutch for the forward or reverse gear is reduced to a residual level.
    Type: Application
    Filed: January 15, 2003
    Publication date: May 19, 2005
    Inventor: Hugo Burkhart
  • Patent number: 6026699
    Abstract: A gear control for reduces the thermal stress on switching components (2, 3, 4, 5, 6) of a reversing gear (1) for machines having an input shaft (8) and an output shaft (15) and at least one directional switch for forward motion (2) and one for reverse motion (3) and a downstream load-switchable switching set (4) with several switching components (5, 6) allocated to a gear. Here the switching components (2, 3, 5, 6) can be electrically and/or hydraulically controlled by a regulating and control device (12) in such a way that, during a switching operation, in addition to one of the directional switching components (2, 3) corresponding to the switching operation, at least one other switching components (5, 6) of the downstream switching set (4) lying in the power flow and fully engaged at the start of a reversal is set to a slip state under frictional load. The frictional load is thus distributed between the directional switching components (2, 3) and the other slipping switching components (5, 6).
    Type: Grant
    Filed: August 10, 1998
    Date of Patent: February 22, 2000
    Assignee: ZF Friedrichshafen AG
    Inventors: Uwe Heitz, Hugo Burkhart, Ralf Dreibholz
  • Patent number: 5823313
    Abstract: A pressure-control device is used to affect the engaging behavior of powershift clutches in a powershift gear with a control valve cooperating with a damping device, as a pressure-control valve (2), by which the pressure cycle can be set on engaging the clutch concerned. The pressure in a chamber (C3), between a displacement piston (4) and a pressure-control piston (3), can be controlled via a first switching valve (11) switched by a magnetic valve (10). A chamber (C2) behind the displacement piston (4) can be exhausted, via a second switching valve (14) switched by the same magnetic valve (10), whereby the pressure-control piston (3) is held in its initial position to release the full valve aperture cross section from the pressure line (1) to the clutch line (7).
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: October 20, 1998
    Assignee: ZF Friedrichshafen AG
    Inventors: Ulrich Bohner, Hugo Burkhart