Patents by Inventor Detlef Plath

Detlef Plath 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: 8777809
    Abstract: A method for operating a transmission of a vehicle drivetrain. A transmission ratio can be automatically changed during an operating state depending on a comparison of current operating state parameters with operating parameters stored in a control unit, and can be manually changed depending on a driver's request. Accordingly when the driver requests a change of the transmission ratio, the transmission ratio changes, and a timer starts. If the driver continues the ratio change from an actual transmission ratio value toward a larger or smaller transmission ratio value, the current operating parameters are compared with the stored operating parameters. Upon this comparison, the transmission shifts to higher ratios in comparison to the operating parameters stored in a control device at higher vehicle speeds, and/or a delay between sequential, cyclical transmission ratio changes varies depending on a vehicle deceleration and/or braking pressure in the region of a vehicle brake.
    Type: Grant
    Filed: January 9, 2013
    Date of Patent: July 15, 2014
    Assignee: ZF Friedrichshafen AG
    Inventors: Detlef Plath, Peter Spoerl, Franz-Josef Schuler
  • Patent number: 8682543
    Abstract: A method of operating a transmission having a plurality of gears which can operate in an automatic shifting mode, during which a gear is selected automatically depending on the current driving situation, and also in a manual shifting mode during which a gear is selected depending on a driver's command. When the driver commands a shift, a change takes place from the automatic shifting mode to the manual shifting mode. A specific threshold value of the transmission output speed or an equivalent rotational speed value is associated with each gear and, when the driver commands a downshift, a target gear is determined as a function of the current transmission output speed or the equivalent rotational speed value. The gear selected as the target gear is the gear whose specific threshold value is higher than or equal to the current transmission output speed or the equivalent rotational speed value.
    Type: Grant
    Filed: May 2, 2011
    Date of Patent: March 25, 2014
    Assignee: ZF Friedrichshafen AG
    Inventors: Detlef Plath, Friedemann Jauch, Franz-Josef Schuler, Peter Spoerl
  • Publication number: 20110320094
    Abstract: A method of operating a transmission device with a plurality of gears which can operate in an automatic shifting mode, during which a gear is selected automatically depending on the current driving situation, and also in a manual shifting mode during which a gear is selected depending on a driver's command. When the driver commands a shift, a change takes place from the automatic shifting mode to the manual shifting mode. A specific threshold value of the transmission output speed or an equivalent rotational speed value is associated with each gear and, when the driver commands a downshift, a target gear is determined as a function of the current transmission output speed or the equivalent rotational speed value. The gear selected as the target gear is the gear whose specific threshold value is higher than or equal to the current transmission output speed or the equivalent rotational speed value.
    Type: Application
    Filed: May 2, 2011
    Publication date: December 29, 2011
    Applicant: ZF FRIEDRICHSHAFEN AG
    Inventors: Detlef PLATH, Friedemann JAUCH, Franz-Josef SCHULER, Peter SPOERL
  • Patent number: 7575528
    Abstract: A continuously variable transmission having an input cone pulley pair and an output cone pulley pair linked by and an encircling mechanism. One pulley of each pair is axially fixed and one pulley is axially displaceable to control the transmission ratio of the transmission. A recoil spring engages between the input moveable pulley and an axially fixed contact surface only when the transmission is in the low transmission ratio range for exerting a force to displace the input moveable cone pulley to a high transmission ratio to avoid damage to the transmission or starting clutch during towing.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: August 18, 2009
    Assignee: ZF Friedrichshafen AG
    Inventors: Detlef Plath, Uwe Firzlaff
  • Publication number: 20050181899
    Abstract: A cone pulley continuously variable transmission comprising one primary pulley pair, one secondary pulley pair and one encircling mechanism spanning the pulley pairs. The distances between the pulleys of each pulley pair are adjustable in opposite directions for changing the ratio by way of hydraulic setting device. A spring device acts upon an axially displacable secondary pulley and a spring device prestresses the input-side primary pulley pair in case of gear distance between its pulleys in direction to reduction of the distance. To improve the mode of operation of such a transmission during a towing process, the spring tensions of the input-side spring device and the output-side spring device is coordinated to prevent, during a towing process with deactivated hydraulic pressure supply, a closing of an input-shaft side starting clutch determined by rotational speed and/or drag torque or damage of the primary pulley or of the encircling mechanism.
    Type: Application
    Filed: November 19, 2004
    Publication date: August 18, 2005
    Inventors: Detlef Plath, Uwe Firzlaff
  • Patent number: 6843740
    Abstract: A hydraulic fluid feed mechanism that feeds into a shaft (1) of a transmission having a hydraulic control device, by which the hydraulic feed mechanism can be supplied with hydraulic fluid, comprising a transmission housing (3) in which the shaft is held, and a housing cover (7) that is equipped with feed bores (8, 9), by which the hydraulic fluid is fed from the hydraulic control device into the shaft (1). A hydraulic fluid line (12) is positioned between the hydraulic or pneumatic control device and a feed bore (9) in the housing cover (7) that extends parallel to the shaft (1), with this hydraulic fluid line being comprised of a fitting (13) and a tube (14) which is permanently inserted into the fitting at nearly right angles, forming a pressure-tight seal.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: January 18, 2005
    Assignee: ZF Friedrichshafen AG
    Inventors: Klaus Müller, Manfred Sulzmann, Detlef Plath
  • Publication number: 20030092518
    Abstract: A hydraulic fluid feed mechanism that feeds into a shaft (1) of a transmission having a hydraulic control device, by which the hydraulic feed mechanism can be supplied with hydraulic fluid, comprising a transmission housing (3) in which the shaft is held, and a housing cover (7) that is equipped with feed bores (8, 9), by which the hydraulic fluid is fed from the hydraulic control device into the shaft (1). It is proposed that a hydraulic fluid line (12) be positioned between the hydraulic or pneumatic control device and a feed bore (9) in the housing cover (7) that extends parallel to the shaft (1), with this hydraulic fluid line being comprised of a fitting (13) and a tube (14) which is permanently inserted into the fitting at nearly right angles, forming a pressure-tight seal.
    Type: Application
    Filed: October 31, 2002
    Publication date: May 15, 2003
    Inventors: Klaus Muller, Manfred Sulzmann, Detlef Plath