Patents by Inventor Franz Gratzer

Franz Gratzer 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).

  • Publication number: 20040132581
    Abstract: A speed-difference-dependent hydraulic clutch comprises a drive housing (11), which rotates in a housing (20), a first shaft (21) which can be connected in a rotationally fixed manner to the drive housing, a second shaft (22) which is connected in a rotationally fixed manner to the drive housing, and furthermore a hydrostatic displacement machine (1), a friction clutch (12) for connecting the first shaft (21) to the drive housing (11), and a piston (10) for acting on the friction clutch (12), the drive housing (11) having a pressure space (9) and where a pressure is produced in the pressure space (9) when a difference in speed occurs in the pressure space (9), this pressure giving rise to action upon the friction clutch (12), and a passage (13) leading from the pressure space to a control valve which opens up the route to a space of lower pressure in a controlled manner.
    Type: Application
    Filed: March 5, 2004
    Publication date: July 8, 2004
    Inventors: Franz Gratzer, Robert Schaffernak
  • Patent number: 6684991
    Abstract: A speed-difference-dependent hydraulic clutch comprises a drive housing (27), which rotates in a housing (25) that is fixed in space and forms a reservoir, a hydrostatic displacement machine (35), an output shaft (30), a friction clutch (36) and a piston (5) for acting on the friction clutch (36), a pressure being produced in a pressure chamber (4) when a difference occurs between the speed of the drive housing (27) and that of the output shaft (30), this pressure giving rise to action upon the friction clutch (36).
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: February 3, 2004
    Assignee: Steyr-Daimler-Puch Fahrzeugtechnik AG & Co KG
    Inventor: Franz Gratzer
  • Publication number: 20030173179
    Abstract: Drive system for an all-wheel driven motor vehicle having a first and a second driven axle (3, 9), which drive system has a differential-speed-dependent clutch (6) for driving the second driven axle, and an at least partially lockable differential (8) between the wheels of the second driven axle (9). The differential-speed-dependent clutch (6) comprises a pump (10) which, when a differential speed occurs, produces a pressure which leads to the transmission of a torque to the second driven axle (9). In order to ensure that the differential lock responds in a manner coordinated neatly in terms of time and taking account of the driving state, a connecting line (18) leads from the delivery side (11 or 12) of the pump (10) to an actuating member (27) of the lockable differential (8), with the result that, when a differential speed occurs, the pressure produced by the pump (10; 67) makes it possible to at least partially lock the differential (8) by means of a positive locking clutch (26).
    Type: Application
    Filed: March 26, 2003
    Publication date: September 18, 2003
    Inventor: Franz Gratzer
  • Patent number: 6484856
    Abstract: A speed-difference-dependent hydraulic, consisting of a stationary rotating gear housing (27) with a housing (25) which forms a reservoir for operating fluid, a hydrostatic displacement machine (35), a drive shaft (30), a friction coupling (36) and a piston (5) to have an impact on the friction coupling (36), by which pressure is created in a pressure chamber (4) when there is a differential speed between the gear housing (27) and the drive shaft (30). In order to achieve quick regulation and adaptation of the characteristics, a first and second opening (9, 10) are connected by means of a first and second rotating insertion (13, 14), and a first and second regulating control valve (15, 16) are connected with the reservoir (8), by which the first and the second control valves (15, 16) are formed as regulating throttle valves, so that independent of the direction of the differential speed, it can be controlled on the respective supply side as well as on the discharge side of the displacement machine.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: November 26, 2002
    Assignee: Steyr-Daimler-Puch Fahrzeugtechnik AG & Co. KG
    Inventor: Franz Gratzer
  • Patent number: 6250444
    Abstract: A hydraulic clutch which is dependent on rotation speed difference comprises a rotating housing (1), a hydrostatic displacement machine (2) arranged in this housing (1), a shaft (4), a friction clutch (3) for connecting the shaft (4) to the housing (1), and a piston (26). In order to limit the torque in a very simple manner without any disturbing centrifugal force influences, and in order to cool the friction clutch, the compression chamber (24) is connected via a constriction point (27) to the interior (28) of the friction clutch (3), and the constriction point is designed as a pressure-limiting valve. This is formed by a plate spring (30) in the wall (29) of the piston (26).
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: June 26, 2001
    Assignee: Steyr-Daimler-Puch Fahrzeugtechnik AG & Co. KG.
    Inventor: Franz Gratzer
  • Patent number: 5547054
    Abstract: A free-wheeling coupling sensitive to the direction of rotation for a motor vehicle comprises a first ring which constitutes a driven element in a towing mode of the vehicle, a second ring which constitutes a driven element in the towing mode, clamping elements (e.g., rollers) which act between the first and second rings to transfer torque between them in both directions of torque flow, a cage in which the clamping elements are disposed, and a friction element acting between the cage and the second ring. The free-wheeling coupling further comprises a fixed switching ring, a cam rotatably mounted on the cage or the first ring, the cam including a control lever, and a spring which urges the control lever into engagement with the fixed switching ring until there is sufficient centrifugal force to lift the control lever out of engagement with the fixed switching ring.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: August 20, 1996
    Assignee: Steyr-Daimler-Puch AG
    Inventor: Franz Gratzer
  • Patent number: 5443147
    Abstract: A rotationally-dependent free-wheeling coupling for a motor vehicle comprises a first ring which constitutes a driving element in the towing mode of the motor vehicle, a second ring which constitutes a driven element in the towing mode, clamping elements which act between the first and second rings to transfer torque therebetween in both directions of torque flow, a cage which holds the clamping elements, and a friction element which causes the cage to rotate with the second ring. The rotationally-dependent free-wheeling coupling further comprises a latch which acts between the first ring and the cage, the latch being mounted for swiveling movement on an axle and entering a recess in the cage, the recess having a wall which constitutes a stop for the latch and defining a neutral (free-wheeling) position, a retaining spring which presses the latch into the recess of the cage, and a slipping spring.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: August 22, 1995
    Assignee: Steyr-Daimler Puch AG
    Inventor: Franz Gratzer
  • Patent number: 5127503
    Abstract: A liquid friction coupling is disclosed, which comprises a housing, which constitutes one coupling part and is filled with a viscous liquid, a shaft, which protrudes into the housing and constitutes the other coupling part, interdigitating disks, which are nonrotatably connected in alternation to the housing and to the shaft, respectively, and spacers disposed between the disks. In order to improve the torque characteristic during an operation involving liquid friction and to achieve a steeper rise of the hump torque, each of the outer or inner disks entirely or in part tends to exhibit a thermal deformation in an axial direction and a spacer ring is provided between each inner disk and an outer disk of an adjacent pair of disks.
    Type: Grant
    Filed: June 27, 1991
    Date of Patent: July 7, 1992
    Assignee: Steyr-Daimler-Puch AG
    Inventor: Franz Gratzer