Patents by Inventor Helmut Fennel
Helmut Fennel 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).
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Patent number: 4975852Abstract: A circuit configuration for controlling the auxiliary-energy supply system of a brake system with anti-lock control and/or traction slip control. A volume pattern (VM) is created by measuring and evaluating quantities which determine the auxiliary energy requirement and, respectively, the pressure fluid flow. The volume pattern represents by approximation the pressure fluid discharge out of the master cylinder of the brake system as well as the pressure fluid requirement and is utilized for controlling the auxiliary-energy supply system (HEV). For forming the volume pattern (VM), a pedal force surplus (PKU) is definable which, in turn, is correlated with the initial gradient.Type: GrantFiled: May 15, 1989Date of Patent: December 4, 1990Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Ivica Batistic
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Patent number: 4930845Abstract: A control system and method for a brake system with anti-locking and/or traction slip control and sequential brake pressure modulation. A modulator pressure pattern is formed in a circuit (33) by measuring and evaluating variables determining the pressure in the control chamber of chambers (21) of a brake pressure modulator (4). The modulator pressure pattern represents, by approximation, the course of pressure in the modulator (4). This modulator pressure pattern is considered in the brake pressure control, that is in determining the excitation periods of the multi-way valves (13-16, 22, 23, 25) determining the pressure in a modulator chamber (21) of the brake pressure modulator (4) and in the wheel brakes (9-12). The pressure pattern is formed by integration of the valve excitation periods of the pressure increase and pressure decrease characteristics of the modulator (4) under consideration or of the entire system.Type: GrantFiled: March 15, 1989Date of Patent: June 5, 1990Assignee: Alfred Teves GmbHInventors: Hans W. Bleckmann, Helmut Fennel, Johannes Graeber, Otto Determann, Ivica Batistic
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Patent number: 4844556Abstract: A method and electronic circuit for use in an automotive vehicle brake system with electronic anti-lock control and/or traction slip control is equipped with circuits for identifying a state of vehicle cornering. The slip of the controlled wheel during the time intervals in which the wheel is running stably, and the control frequency or the duration of the control cycles are measured. If the wheel slip exceeds a constant predetermined limit value or a value which depends on the velocity of the vehicle, and if, simultaneously, the control cycles are short on identification of vehicle cornering and corresponding signal is generated.Type: GrantFiled: August 12, 1988Date of Patent: July 4, 1989Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Norbert Ehmer
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Patent number: 4773072Abstract: A method and a circuit configuration for suppressing sporadic interferences in the processing of data by means of two circuit systems (2, 3, MC1, MC2). The circuit systems redundantly process the data and, for the purpose of detecting errors and interferences, between the circuit systems data (D1n, D2n) is exchanged and compared for agreement. If the comparators (15, 16, 25', 41.2, 43.1, 46.2, 49.1) detect differences the transferred data will be taken over and the data processing will be continued with the transferred data. This takes place in several consecutive cycles. As soon as the predetermined scope or a predetermined number of cycles with differences between the compared data is exceeded an error will be evaluated and indicated. The circuit configuration is suitable for increasing the tolerance of electronic control circuits (ER) of the type for slip-controlled brake systems.Type: GrantFiled: May 21, 1986Date of Patent: September 20, 1988Assignee: Alfred Teves GmbHInventor: Helmut Fennel
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Patent number: 4746173Abstract: A slip-controlled hydraulic brake system for all-wheel driven motor vehicles equipped with lockable differentials (2, 3) is provided with sensors (S.sub.1 -S.sub.4, 33-36) for measuring the rotational behavior of the wheels. Electronic circuits (44) are provided for logic combining and processing the sensor signals, and for generating braking pressure control signals by way of which the brake pressure in the individual wheel brakes (16-19) is variable in response to the rotational behavior of the wheels and to a reference variable. To compensate the increased moments of inertia as a result of the moments transmission, by way of the lockable differentials (2, 3) in this brake system the brake pressure in the rear-wheel brakes (18, 19), can be modulated at a lower control frequency as compared with the brake pressure in the front-wheel brakes (16, 17).Type: GrantFiled: October 2, 1986Date of Patent: May 24, 1988Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Hans Wupper, Gunther Buschmann, Norber Ehmer
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Patent number: 4739484Abstract: A method and device for controlling the variation of braking pressure in the wheel cylinders of brake-slip controlled vehicle brakes. The wheel rotational behavior (v.sub.Rad) and further a vehicle reference velocity (v.sub.Ref) are determined by sensors and logically combined to produce control signals. The braking pressure at the wheels is controllable by the operation of electromagnetically actuated valves (AV, EV) inserted in the pressure fluid circuit. A first pressure-decrease pulse is triggered as soon as the wheel velocity exceeds a deceleration or slip threshold during a braking action. The duration of the said pressure-decrease pulse is determined by the instantaneous deceleration upon attainment of the first switching threshold. Any subsequent pressure decrease pulse is delivered only after a predetermined waiting period and is of a duration determined by reference to the average acceleration.Type: GrantFiled: March 25, 1987Date of Patent: April 19, 1988Assignee: ITT Industries, Inc.Inventor: Helmut Fennel
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Patent number: 4736994Abstract: To control the braking pressure in the wheel brakes of a slip-controlled hydraulic brake system for automotive vehicles with all-wheel drive and with lockable or automatically locking differentials (2, 3), a circuit configuration is provided which influences the variation of the vehicle reference speed (v.sub.REF). This is to say, in the event of the wheel (v.sub.Rn) which is momentarily decisive for the formation of references becoming instable, the reference speed (v.sub.REF) will first be declined with a relatively flat gradient which corresponds to a vehicle deceleration at a low frictional coefficient. A decrease of the vehicle reference speed (v.sub.REF) with a very steep gradient will follow after a predetermined period of time (T.sub.1). This decrease is continued until the vehicle reference speed (v.sub.REF) reaches the decisive wheel speed again or falls thereunder. To avoid oscillations, the change-over of the reference (v.sub.REF) after the attainment of the wheel speed curves (v.sub.Type: GrantFiled: October 2, 1986Date of Patent: April 12, 1988Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Hans Wupper, Gunther Buschmann, Norbert Ehmer
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Patent number: 4729608Abstract: A method for controlling an anti-lock brake system for automotive vehicles with all-wheel drive. Electric signals representative of the rotational behavior of the wheels are generated and logically combined. Upon the occurrence of a tendency to lock, the braking pressure is modulated wherein the instantaneous wheel slip, wheel acceleration and wheel deceleration are evaluated as control criteria and the individual wheel speed (v.sub.R) is compared in each case with a vehicle reference speed (v.sub.REF) which serves as a reference value for the modulation of braking pressure. In the event of a wheel rotational behavior that is typical of spinning and that shows in the rise of the vehicle reference speed (v.sub.REF) in excess of the actual vehicle speed (v.sub.Type: GrantFiled: June 19, 1986Date of Patent: March 8, 1988Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Hans Wupper, Gunther Buschmann, Johannes Graeber, Norbert Ehmer
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Patent number: 4718736Abstract: To modulate the pressure reduction when controlling wheel slip by means of an anti-lock hydraulic brake system, electric signals representative of the rotational behavior of the individual wheels are reconditioned and combined electronically. Upon the occurrence of a tendency to lock, a pressure-reducing valve (17, 17', 19, 19', 21, 21') is actuated pulsewise, and thereby pressure fluid out of the wheel brake cylinder is returned into a supply reservoir (11). When varying the pulse/pulse-pause ratio of the actuating signals (i.sub.AV), additionally the pressure/time characteristic curve of the brake system is taken into consideration by increasing the pulse/pulse-pause ratio after a predetermined period of time, that is time of pressure reduction or number of pulses, with the pressure-reducing signal continuing to exist. The change in the actuating signals (i.sub.AV) for the improvement of the pressure reduction is effected in one or in several steps or quasi-continuously.Type: GrantFiled: June 20, 1986Date of Patent: January 12, 1988Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Hans Wupper
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Patent number: 4701855Abstract: A method and a circuit configuration for suppressing undesired control actions in slip-controlled brake systems, which, for example, may be caused by oscillations of the axle. The wheel rotational behavior is determined and the braking pressure is controlled in dependence upon slip criteria and/or acceleration criteria, and slip control commences when predetermined threshold values (-b.sub.N) are exceeded. A threshold value decisive for initiation of the control is varied as a function of re-acceleration of the controlled wheel.Type: GrantFiled: December 5, 1984Date of Patent: October 20, 1987Assignee: ITT Industries, Inc.Inventor: Helmut Fennel
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Patent number: 4688858Abstract: A slip-controlled brake system comprises two hydraulically separated pressure medium circuits, to which the wheel brakes (14, 15 and 16, 17, respectively) of the wheels arranged diagonally at the vehicle are connected. In one diagonal (brake circuit 9) the braking pressure during slip control is controlled in phase, whereas in the second diagonal (brake circuit 10) individual brake slip control is possible by way of two individual inlet and outlet valve pairs (11, 18; 12, 19).Type: GrantFiled: July 16, 1985Date of Patent: August 25, 1987Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Ivica Batistic, Otto Determann
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Patent number: 4675819Abstract: For the generation of a vehicle reference speed to serve as the reference value for the control of brake slip and/or traction slip in automotive vehicles, the rotational behavior of the controlled wheels is measured. The vehicle reference speed is defined by virtue of the rotational behavior of the individual wheels by way of logic combining, selection according to predetermined criteria and/or comparison with predetermined limit values. The wheel rotational behavior of each wheel is evaluated in comparison to the wheel-related vehicle reference speed (V.sub.Ref) according to several predefined criteria is then classified into reference-defining periods. As a function of ascertained reference-defining period, a vehicle reference value (b.sub.fzg) related to the individual wheel is determined which, together with the wheel-related vehicle reference values of the other wheels, determines the vehicle reference speed.Type: GrantFiled: December 5, 1984Date of Patent: June 23, 1987Assignee: ITT Industries, Inc.Inventor: Helmut Fennel
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Patent number: 4657313Abstract: A slip-controlled brake system for road vehicles in which one front wheel (VR, VL) and one rear wheel (HR, HL) at a time are connected to a common braking pressure control channel wherein the braking pressure variation in the two braking pressure control channels is influenced in dependence on predetermined selection criteria such as "select-low" and "select-high" criteria. A cornering identification circuit (20') is provided which adds up the slip values (S.sub.VL, S.sub.HL, S.sub.VR, S.sub.HR) of the two wheels of one side of the vehicle and compares them with the slip value sum (S.sub.L, S.sub.R) of the wheels of the other side of the vehicle. When the difference of the slip value sums of the two sides of the vehicle exceeds a limit value, the selection criteria and, hence, the braking pressure variations are temporarily changed. Because of the cornering identification circuit, it is possible to generate information about the driving direction, i.e.Type: GrantFiled: April 12, 1985Date of Patent: April 14, 1987Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Ivica Batistic
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Patent number: 4648662Abstract: A circuit configuration for a slip-controlled vehicle brake system is equipped with sensors (10-13) for the determination of the rotational behavior of the front and the rear wheels and with electronic circuits (18, 30) for the processing, logic combining and monitoring of the sensor signals and for the generation of control signals. The control signals allow control of the braking pressure variation at the wheels. Upon failure or malfunction of a sensor (10-13) or in the event of an interference in the signal path, the brake slip control is switched over to being responsive to the rotational behavior of another wheel according to a predetermined selection criterion.Type: GrantFiled: May 8, 1985Date of Patent: March 10, 1987Assignee: Alfred Teves GmbHInventors: Helmut Fennel, Hans Wupper
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Patent number: 4643492Abstract: A brake system with slip control for vehicles with front-wheel drive or all-wheel drive comprises two hydraulically isolated pressure-medium circuits (2, 3), to which one front wheel and one rear wheel each (VL, HR; VR, HL) are connected. Through a pair of valves (17, 19; 18, 20) consisting of inlet valve and outlet valve, the braking pressure in the two hydraulic pressure-medium circuits is varied upon recognition of an imminent locked condition. The braking pressure in the front-wheel brake is maintained constant by one additional valve (21, 22) connected upstream of the front-wheel brakes (4, 6) in the event of decrease or in the event of further increase of the pressure in the rear-wheel brake (5, 7) that is connected to the same hydraulic pressure-medium circuit (2 or 3, respectively).Type: GrantFiled: July 11, 1985Date of Patent: February 17, 1987Assignee: Alfred Teves GmbHInventors: Juan Belart, Helmut Fennel, Wolfram Seibert, Ivica Batistic
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Patent number: 4626043Abstract: A slip-controlled brake system for automotive vehicles with a driven axle and a non-driven one has a braking pressure generator (10) connected to an auxiliary pressure source (9), to the braking pressure generator (10) the wheel brakes of a front wheel (VR, VL) and of a rear wheel (HR, HL) are connected by way of two separate pressure medium circuits. The braking pressure in the two circuits (I, II) at first is jointly controlled by means of an inlet valve and an outlet valve each (5, 13 and 7, 14 respectively). However, a far-reaching decoupling of the pressure variation in the two wheel brakes connected to one circuit (I or II, respectively) is achieved by means of additional 2/2-way valves (6, 15) in the pressure medium line towards the wheel brakes of the non-driven wheels (HR, HL).Type: GrantFiled: February 27, 1985Date of Patent: December 2, 1986Assignee: Alfred Teves GmbHInventors: Juan Belart, Helmut Fennel, Wolfram Seibert, Ivica Batistic
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Patent number: 4581713Abstract: A method and a device for the generation of numerical values which are proportional to the frequency of the measured pulses of a measured-pulse train are proposed which make available the numerical values covering a wide measuring range with high precision and in a shortest possible time. To this end, in invariably predetermined reference time intervals, the number of the periods of the measured pulses is in each case measured as an approximate value for the frequency, and a correction value is added to the approximate value. The correction values are contained in at least one table as table values under respective addresses, the table values being derived from the difference between the time durations measured in successive reference time intervals up to the respective last measured pulse in the reference time interval.Type: GrantFiled: March 30, 1983Date of Patent: April 8, 1986Assignee: ITT Industries, Inc.Inventor: Helmut Fennel
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Patent number: 4546437Abstract: To control a brake slip control apparatus, the rotational behavior of the wheels or of the axles is sensed with the aid of sensors, and the sensor signals for the generation of valve control signals, by which the braking pressure at the wheels is controlled dependent upon the wheel rotational behavior, will be processed electronically. On the basis of these sensor signals, valve control signals will be produced in at least two independently acting, synchronously driven logical circuit units, which may be integrated circuit configurations or complete "microcontrollers" or single-chip-microcomputers, and the signals' waveforms of each of the two circuit units can be compared and checked for agreement externally and internally at corresponding locations within the two circuit units. Upon the occurrence of variations in the external and/or the internal signals or in the signals' waveform, there will be caused, initiated or prepared a complete or partial disconnection of the brake slip control.Type: GrantFiled: June 27, 1983Date of Patent: October 8, 1985Assignee: ITT Industries, Inc.Inventors: Hans-Wilhelm Bleckmann, Heinz Loreck, Helmut Fennel, Michael Zydeck