Patents by Inventor Hans Drewitz

Hans Drewitz 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: 5052987
    Abstract: A stepless hydrostatic mechanical transmission between a prime mover and a power output train in which an epicyclic differential is incorporated in the transmission and includes at least four shafts, a large and a small sun wheel, two planet wheels in mesh with the sun wheels, a web supporting the planet wheels and an annulus. Two main shafts constituting input and output shafts are connected with respectively different shafts of the epicyclic differential. Two hydrostatic machines are connected to the epicyclic differential such that in at least one working range of the power transmission the hydrostatic machines are adapted to be connected to the epicyclic differential and operated as pumps and motors.
    Type: Grant
    Filed: March 23, 1990
    Date of Patent: October 1, 1991
    Assignee: Man Nutzfahrzeuge AG
    Inventors: Faust Hagin, Hans Drewitz
  • Patent number: 4976664
    Abstract: A drive device for vehicles comprises: a drive prime mover, a power splitting hydrostatic mechanical transmission coupled with the prime mover and having a planetary differential transmission with at least four shafts and two groups of planet wheels, two sun wheels, a web and an annulus, two main shafts forming an input and output and connected with different shafts of the planetary differential transmission, a clutch two variable displacement hydrostatic machines which are respectively connected in at least one operational range with a respective shaft of the planetary differential transmission and are adapted to alternately operate as a pump and as a motor, a first hydrostatic machine which, when the second hydrostatic machine is stationary, being able to be switched over from the input main shaft to the sun wheel, not on the drive side, on transition from one to the other operational range by means of said clutch means and during traction operation is switched over from the motor to the pump function.
    Type: Grant
    Filed: July 5, 1989
    Date of Patent: December 11, 1990
    Assignee: Man Nutzfahrzeuge Aktiengesellschaft of Munchen
    Inventors: Faust Hagin, Hans Drewitz
  • Patent number: 4959962
    Abstract: In order to avoid the necessity of a conventional electric starter motor a hydrostatic starting system for the engine of a motor vehicle is proposed for the engine whose output shaft is connected with a hydromechanical power transmission, composed of a mechanical part and at least two hydrostatic machines. The starter system comprises its own hydraulic accumulator which as regards its filling capacity and power output is designed for starting the engine at least once and a controller which responds to certain halt and operational states of the vehicle. The charging of the hydraulic accumulator takes place during braking of the vehicle via the hydrostatic machines of the power transmission or, if there is insufficient brake power, of an auxiliary device.
    Type: Grant
    Filed: February 7, 1990
    Date of Patent: October 2, 1990
    Assignee: MAN Nutzfahrzeuge GmbH
    Inventors: Faust Hagin, Hans Drewitz
  • Patent number: 4875557
    Abstract: A device for automatically resetting the play between a brake lining and a rotating brake member which is to be braked. The device is able to take into account an increase in the play due to wear as well as a decrease in the play due to overadjustment due to internal elasticity and heating, during each braking operation by suitably dimensioned positive and negative resetting. The device employs a setting member which is rotatable in a housing and with which a coupling can be engaged to drive a setting shaft and thereby take up play during braking. As the braking force increases, the coupling is locked against rotation and as the setting shaft undergoes further displacement, the play is slightly increased.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: October 24, 1989
    Assignee: MAN Nutzfahrzeuge GmbH
    Inventors: Faust Hagin, Hans Drewitz, Manfred Krenner
  • Patent number: 4843907
    Abstract: A hydromechanical power splitting transmission for use between the prime mover and the axle power train of a vehicle having a planetary differential drive with at least two series of planetary wheels, two sun wheels, a web and annulus, a drive input shaft and a drive output shaft, connected with different shafts of the planetary differential drive. There are furthermore at least first and second hydrostatic machines, which in at least one operational range are connected with one shaft of the planetary differential drive and at least the first of the hydrostatic machines is able to be switched over from its own shaft to another on changing the operational range by clutches, while the second hydrostatic machine is at least substantially stationary. In the operational state of the vehicle in which the ratio of n.sub.output to n.sub.
    Type: Grant
    Filed: August 2, 1988
    Date of Patent: July 4, 1989
    Assignee: MAN Nutzfahrzeuge GmbH
    Inventors: Faust Hagin, Hans Drewitz
  • Patent number: 4825722
    Abstract: The hydromechanical transmission is all in all designed as a power splitting transmission having at least two hydraulic machines adapted to selectively act as pumps and motors, a control or connecting block, epicyclic gearing and various clutches, the hydraulic machines adapted to selectively act as pumps and motors forming a preassembled unit or subassembly with the control or connecting block. The subassembly, the epicyclic gearing, the clutches and any intermediate shaft required are arranged in a unitary manner in a common housing, in which the various elements are surrounded with a small clearance. the hydraulic machines adapted to selectively act as pumps and motors are arranged within the overall length of the epicyclic gearing and are axially parallel thereto.
    Type: Grant
    Filed: January 23, 1987
    Date of Patent: May 2, 1989
    Assignee: MAN Nutzfahrzeuge GmbH
    Inventors: Faust Hagin, Hans Drewitz, Stefan Martini
  • Patent number: 4778020
    Abstract: The invention is concerned with improvements in utility vehicles having hydraulically driven items of equipment and designed for frequently stopping and starting, such as a garbage collection vehicle, a forklift truck, an excavator or the like. In order to facilitate operation of the equipment the vehicle has its engine connected with a hydromechanical four-shaft power branching transmission as previously proposed for use in city omnibuses operating city services. The branching transmission is adapted for operation in at least two working ranges and has at least two hydroconverters. The one hydroconverter is connected with a power output shaft at least in the starting up state of the vehicle. A second hydroconverter is connected with a shaft different to the transmission input shaft and the transmission output shaft.
    Type: Grant
    Filed: May 27, 1987
    Date of Patent: October 18, 1988
    Assignee: MAN Nutzfahreuge GmbH
    Inventors: Faust Hagin, Hans Drewitz