Patents Assigned to Zahnradfabrik Friedrichshafen AG
  • Patent number: 5086863
    Abstract: An all-wheel steering system for motor vehicles includes an adjusting motor (10) for the rear wheels. The motor has a piston rod on which two fixed working pistons (25 and 25A) and, in a housing segment located between the working pistons, two movable steering pistons (27 and 27A) are mounted. The working pistons (25 and 25A) and steering pistons (27 and 27A) form control chambers (28 and 28A) that are constantly connected to a pump (2). Between the steering pistons (27 and 27A) is a pressure chamber (33) in which a spring element (34) acts upon the steering pistons (27 and 27A). The pressure chamber (33) can be blocked via a 2/2-way valve (37) that is controlled by a switching device (17) or it can be connected with a tank (3). When the rear-wheel steering system (11) is in the operating position, the two steering pistons (27 and 27A) come to rest against a sleeve (35) on the piston rod by virtue of the pump pressure that is fed into the control chambers (28 and 28A).
    Type: Grant
    Filed: November 2, 1990
    Date of Patent: February 11, 1992
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventor: Werner Tischer
  • Patent number: 5086687
    Abstract: An auxiliary power steering mechanism with a working piston installed in the steering gear has a rotary valve comprising a rotary member and a fixed valve sleeve. A piston valve is inserted in a bore provided in the rotary member. The piston valve is connected with an adjustment device, such as an electromagnet, via a tube supported by a torsion bar. The electromagnet adjusts the piston valve as a function of various influencing variables such as speed, and controls the condition of a plurality of hydraulic fluid flow return bores arranged in longitudinally spaced relation in the rotary member for noise-free control of the build-up of pressure in a surge chamber that is active at the moment. The bores have flat portions of different contours and circumferential lengths.
    Type: Grant
    Filed: January 31, 1989
    Date of Patent: February 11, 1992
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Dieter Elser, Helmut Hetzel, Walter Kogel
  • Patent number: 5086864
    Abstract: The invention is concerned with a device that cuts off pressure in the final positions of the steering movement in an auxiliary-power steering device. In steering devices that have movable working pistons in the steering gear housing, this cut-off device is installed in a through drilled hole in the working piston. A by-pass valve that is activated by a push rod touching the wall of the housing is provided for every direction of steering. To avoid time-consuming adjustment work on the by-pass valves the walls contain bushings located opposite the push rods that are automatically pushed into the final positions corresponding to the wheel steering angle after the auxiliary-power steering device is installed in the vehicle. That happens as a result of rotating, first without auxiliary power, against the wheel limit stops, with the front axle jacked up, after the preliminary installation of the bushings in their drilled holes.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: February 11, 1992
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventor: Dieter Elser
  • Patent number: 5080186
    Abstract: A servo assisted power steering system for motor vehicles comprising a steering-wheel shaft (2) which is connected via a rotary slide valve (6, 7, 8) and a worm-gear spindle (4) of a steering gear (5). The rotary slide valve controls the pressure impacting on a working piston (15) in a hydraulic power boost device. A power takeoff shaft (20) of an electric motor (21) is connected with the rotary slide (7) of rotary slide valve. In case of a rotary motion of steering-wheel shaft (2), a sensor (22) so activates electric motor (21) that a small counterforce is generated upon rotary slide (7) and that force works against the rotary motion of steering-wheel shaft (2). After completion of the rotary motion of steering-wheel shaft (2), as the steering wheel is let go, rotary slide (7) is moved back all the way into its neutral position by the electric motor.
    Type: Grant
    Filed: November 2, 1990
    Date of Patent: January 14, 1992
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Dieter Elser, Heinrich Holub, Rudolf Schurr
  • Patent number: 5080207
    Abstract: Servo-assisted gear selection for a vehicle gearbox and gear change controlled by the driver by actuating the clutch, wherein the driver is informed of the selection having been performed in the gearbox by a haptic or tactile signal at the clutch pedal. The signal is transmitted mechanically from an electromagnet to the clutch pedal, or the electromagnet is arranged in the pedal plate of the clutch pedal. The signal generator may also consist of an electromagnet in conjunction with a pressure piston, which acts on the pressure line of the clutch actuating mechanism, or of an electropneumatic valve in conjunction with a differential piston signal generator.
    Type: Grant
    Filed: January 17, 1990
    Date of Patent: January 14, 1992
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventor: Franz Horneffer
  • Patent number: 5080637
    Abstract: A hydrostatic-mechanical power-distribution transmission with infinitely variable gear ratio in the hydrostatic branch and several ratios in the mechanical branch, which downstream of the coupling gear has shiftable planetary reduction gears for the purpose of reducing the power contribution of the hydrostatic branch in the starting range.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: January 14, 1992
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Peter Tenberge, Abdul Arain
  • Patent number: 5079965
    Abstract: The invention concerns a gearbox (9). On the gearbox is front-mounted a hydrodynamic torque converter (3). The gearbox (9) has hydraulically actuatable gear clutches (17, 18, 23 and 28) which are designed structurally alike. The gears (14, 15, 16, 19, 20, 21, 22, 24, 26 and 27) are in constant engagement with each other. In order to reduce the development of noise, the gears are high and helically toothed. The gearbox is especially suited for use in vehicles in which special importance is attached to comfortable riding. Such vehicles are, for instance, passenger cars and mobile homes.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: January 14, 1992
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Fritz Leber, Michael Herlitzek
  • Patent number: 5072585
    Abstract: Hydrostatic auxiliary power steering devices transmit the steering power to the steered wheels via oil pressure. Such devices utilize a metering pump 5 and a steering valve 2 combined into a single unit. The metering pump distributes oil flow produced by a power steering pump 1 to a pressure operated steering power cylinder 8 under control of a steering valve 2 responsive to drive rotation of the vehicle steering wheel. The oil flow synchronizes the angle of rotation of the steering wheel with the angle of the lock of the wheels being steered. In hydrostatic systems there is a tendency to pressure oscillations. In the present invention these oscillations are minimized without occurring excessive pressure loss. The arrangement provides an inlet conduit 4 for steering, a damping valve 11 having a damping piston 12 centered by springs 13, 14 and closing off a branch conduit 6 which stops flow to the metering pump 5.
    Type: Grant
    Filed: May 31, 1990
    Date of Patent: December 17, 1991
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventors: Rolf Fassbender, Bernd Ilg
  • Patent number: 5072802
    Abstract: A control mechanism for two consumers includes a flow divider valve (3) which is connected to a pump 2. From flow divider valve (3) springs a flow line (12) for the working flow (A) of a first adjustment device (10) such as a steering motor. Another flow line (13) of the flow divider valve (3) leads via an activation valve (14) to a second adjustment device (15). A pilot flow line (4) connected with the flow divider valve (3) via a measurement diaphragm (3A), is connected with a pilot valve (5). Pilot valve (5) can choke or entirely block the connection from the pilot flow line (4) to a nonreturn line (11) for the purpose of setting a pressure in flow line (12). For purposes of activation, pilot valve (5) is coupled with a steering valve (6) that controls flow line (12) so that both valves can be deflected together during one steering movement. A hydraulic steering unit is provided as the steering mechanism and it includes a rod-set connection from a manual steering wheel to the vehicle wheels.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: December 17, 1991
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventor: Werner Tischer
  • Patent number: 5072586
    Abstract: A hydrostatic auxiliary power steering mechanism with load-dependent performance for controlling a variable displacement pump includes an orifice for generating a pressure difference. A control valve in a valve borehole contains a movable valve piston. Orifice is formed between the discharge opening cross-section of a pressure line into the valve borehole and a central spool land provided on valve piston and reveals a cross-section that can be altered as a function of the position of the control valve. The cross-section of orifice has its smallest value when the control valve is in the neutral middle position and can be made larger by adjusting the control valve in both directions.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: December 17, 1991
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventor: Rolf Fassbender
  • Patent number: 5069111
    Abstract: A hydraulic pressure-control device, specially for powershift transmissions of motor vehicles, comprises a fluid pump (1) and a main valve for regulating the pressure in at least one high-pressure consumer device (6), which is attached to a pressure pipe (3) between the fluid pump (1) and the main pressure valve. The main pressure valve is designed as pressure-relief valve. In the main pressure valve is integrated the operation of a second pressure-relief valve. Two different pressure limits can be adjusted in the pressure pipe (3) by a valve piston (21) through two compression springs (17, 18) connected in parallel of which one compression spring (18) is bound.
    Type: Grant
    Filed: October 3, 1989
    Date of Patent: December 3, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Alfons Loffler, Walter Marte, Peter Wiggermann
  • Patent number: 5067362
    Abstract: A standard H transmission set with a manual shifting lever has affixed to the gear box a servocontrol unit which allows shifting between road, travel, farm operation and reverse groups so that the full range of manual selection is available in each of these groups utilizing a selector on the handle of the gear-shift lever which operates solenoid valves controlling servovalves all of which are built into the servocontrol casing.
    Type: Grant
    Filed: November 22, 1989
    Date of Patent: November 26, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventor: Willy Holdenried
  • Patent number: 5063904
    Abstract: In a mechanically driven supercharger (1) whose rotor (6) is propelled by an internal combustion engine by way of a primary shaft (2), a planet gear (8) that is geared up and a rotor shaft (7), the working life of a support (11, 12) for the rotor shaft (7) is increased. For that purpose, the support floats with radial play (17) and axial play (19) in a fixed housing section (10) of the supercharger (1).
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: November 12, 1991
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventors: Siegfried Winkelmann, Karl Schlichtig, Harald Breisch
  • Patent number: 5056639
    Abstract: A device for the control of an automatic motor vehicle clutch is arrayed between an engine and a geaar box and acts primarily as a start-up clutch. A control device receives an electric signal coming from an electronic control device and transforms it into a control quantity for an actuator which engages and disengages the clutch. The engagement of the clutch at start-up occurs with a basic clutch-in speed dependent upon the positioning of the gas pedal and initiated by this positioning and is determined as an electric signal by an electronic control device. For this purpose, a characteristic curve which was determined specifically for the engine is stored in the memory of the electronic control device so that in dependence on the displacement angle of the gas pedal the basic clutch-in speed can be determined very quickly and in a simple manner. It is possible to further improve the quality of the clutch-in process by means of correction factors which are multipliers for the basic clutch-in speed.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: October 15, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Rainer Petzold, Norbert Wiencek
  • Patent number: 5056632
    Abstract: Auxiliary power actuated clutch and gear shifting device for a motor vehicle transmission with function selector and a gear change mechanism controlled by the driver through a clutch actuating mechanism at the clutch pedal wherein a response signal to the driver is received when a gear is engaged in the transmission or the transmission is in neutral. Located at the clutch pedal and connected with it mechanically is a safety device that holds the actuated clutch pedal against movement when a gear is disengaged in the transmission during the shifting of gears. The safety device holds the clutch pedal clamped in actuated position until a gear is engaged in the transmission whence the driver can carry out the procedure of engaging the clutch again in known fashion. The safety device consists of a clamping mechanism that grips a piston rod connecting to the clutch pedal to prevent further operation until the clutch pedal is released.
    Type: Grant
    Filed: January 31, 1990
    Date of Patent: October 15, 1991
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Norbert Lemp, Rainer Petzold
  • Patent number: 5054595
    Abstract: A locking synchronizer for transmission shifts, has a sliding sleeve carrier and a gear revolving at different speeds of rotation coupled together upon attaining synchronism via an axially slidable, annular sliding sleeve. A coupling tooth array of the sliding sleeve engages a corresponding spur gearing of the sliding sleeve carrier as well as a coupling tooth array of the gear, with engagement pins positioned between the sliding sleeve carrier and sliding sleeve. Portions of the gear form with portions of the synchronizing ring a coupling capable of transmitting force and with locking teeth on the synchronizing ring for the temporary prevention of the axial movement of the sliding sleeve, whereby the preventive action is cancelled even during existing difference in speed of rotation as a function of the warming on the synchronizing ring or a defined unlocking force which acts transversely to the motion of the sliding sleeve on the locking teeth of the synchronizing ring.
    Type: Grant
    Filed: June 1, 1990
    Date of Patent: October 8, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Rolf Lutz, Franz Reinalter, Heinz Fiechtner
  • Patent number: 5041064
    Abstract: In a superimposed steering gear (3) for tracklaying vehicles in which the steering power needed for turning is superimposed on the drive system via summarizing differentials and which has a hydrostatic-mechanical power branching summed up in a summarizing transmission (31), the power losses of the hydrostatic branch that works with poor efficiency are kept as small as possible and, at the same time, an infinite steering is made possible over all radial ranges. For this purpose, the summarizing transmission (31) is shiftable into steps that cover at least two radial ranges, a speed adaptation to the transmission components taking place at any given time in the shift points for an infinite transition.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: August 20, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Hans-Jurgen Eickhoff, Peter Tenberge
  • Patent number: 5040631
    Abstract: In an electrically-assisted rack and pinion auxilliary steering mechanism, an electric motor is controlled in accordance with a signal from a torque-measuring device. To prevent faulty control messages, a safety switching device is provided that contains two switches capable of being activated by a lever. A ball nut that is connected with a threaded spindle by a ball diversion channel is connected with the steering rack of the rack and pinion steering gear. The threaded spindle is connected via a spring bellows, with an output part of a coupling that can be coupled with or uncoupled from the electric motor. The threaded spindle is connected, axially movable and rotatable, opposite the fixed housing by two elastic intermediate rings and two axial bearings. If the axial movement does not coincide with the torque at the steering wheel in case of a malfunction, the coupling is disengaged by one of the two switches.
    Type: Grant
    Filed: November 27, 1989
    Date of Patent: August 20, 1991
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Armin Lang, Helmut Knodler
  • Patent number: 5033324
    Abstract: Gearshift console (2) with one gearshift lever (3) for shifting a gearbox (1) of group design, primarily for farm tractors, wherein the gears (G1 through G4) formed in the basic transmission (11) are shifted manually and mechanically in an H pattern and two drive gear groups (L, S) and one reverse group (R) are additionally shifted. To achieve this, gearshift lever (3) is provided with a shifting knob (4) which can be turned into three shifting positions and shifts the three groups of the gearbox (1) with power assist, and in a gear selected in the basic transmission (11), the shifting knob (4) is locked directly in the gearshift console (2). The group shifting is blocked in a simple manner via guide webs (22) arranged on the gate plate (21) by means of two pawls (33) in each direction of drive which can be rotated via said shifting knob (4).
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: July 23, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventor: Reiner Glaser
  • Patent number: 5029682
    Abstract: A brake system for full-track vehicles having a shift gear (3) and superimposed steering gears (8) situated across the longitudinal axis (F) of the vehicle and two summing transmissions (5) situated near the two transmission output shafts (54). The shift gear and the superimposed steering gears, the same as the summing transmissions and other gears and devices, are situated as assemblies (A, B, C, D, E, P) in or upon a common housing and form a common transmission system. The brake system consists, in a first embodiment, of a secondary retarder (1) and a friction brake (2), both situated before the summing transmission. In normal braking, the secondary retarder (1) is first pressurized with the brake actuation device and only later is the friction brake (2) pressurized. In a second example of use a primary retarder (7) and a secondary retarder (1) are situated in the area of the shift gear, and the braking down to stoppage results from one or more shift brakes (B1, B2, B3) in a second function.
    Type: Grant
    Filed: September 8, 1989
    Date of Patent: July 9, 1991
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventors: Norbert Maurer, Horst Kontny, Bernhard Binger