Abstract: A hydraulic circuit for actuation of a hydraulic working cylinder (1) having a one-sided piston rod (1a), comprising a reversible pump (4) whereby both sides of said pump are connected via a supply line (5) and a first two-way valve (6) to the tank (7) containing hydraulic medium and through releasable control check valves (8) to the working cylinder (1). Both sides of the arrangement are further connected respectively to a hydraulic closeable valve (21, 31) through a discharge line (20, 30) and also to the tank (7) through a replenishing suction line (22, 32) having a corresponding suction valve (9). Each of said hydraulic closeable valves (21, 31) is controlled by the pump (4) through a second two-way valve (4).

Abstract: A method is proposed for determining a clutch application point in a transmission of a vehicle having a spring-actuated clutch system in which the clutch application point is adapted according to at least one adequate regulated quantity of the clutch system.

Abstract: A method is proposed for determining a clutch application point in a transmission of a vehicle having a spring-actuated clutch system in which the clutch application point is adapted according to at least one adequate regulated quantity of the clutch system.

Abstract: A known device for increasing the functional reliability for a hydraulic circuit of a hydraulic clutch having a pressure reservoir (25) and a release cylinder (5) which comprises a primary piston (14) and a secondary piston (16). A compensation volume is developed in the sense that when the vehicle is at a standstill and the parking brake released, an unintentional release of the clutch is prevented. A pressure-monitoring/pressure-supply device (28) is used for determining a reference operating pressure and establishes a static pressure which, in case of any system error, only allows displacement of the secondary piston (16) such that the contact pressure of the clutch discs, against one another, is still sufficient to maintain the vehicle at a standstill.

Abstract: A hydraulic circuit for actuation of a hydraulic working cylinder (1) having a one-sided piston rod (1a), comprising a reversible pump (4) whereby both sides of said pump are connected via a supply line (5) and a first two-way valve (6) to the tank (7) containing hydraulic medium and through releasable control check valves (8) to the working cylinder (1). Both sides of the arrangement are further connected respectively to a hydraulic closeable valve (21, 31) through a discharge line (20, 30) and also to the tank (7) through a replenishing suction line (22, 32) having a corresponding suction valve (9). Each of said hydraulic closeable valves (21, 31) is controlled by the pump (4) through a second two-way valve (4).

Abstract: A method for clutch actuation at low temperatures for a motor vehicle having a hydraulically actuatable clutch, below a predetermined temperature a situation-dependent pre-opening of the clutch is executed when a braking is probable.

Abstract: A device for rendering a hydraulic actuating device operational. A motor vehicle clutch with an emitter-receiver system located in the transmission path of the actuating device comprising two pistons whose positions, relative to one another, can vary as a function of the desired operating behavior of the actuating device and is developed further such that in relation to the emitter-receiver system that is to be filled with fluid, operationality can be established comparatively quickly and by simple way. A fluid supply unit (24) comprises one impulse valve (25) that serves to release an essentially constant volume flow, acted upon by an impulse valve control device (26) which is constructed such that the fluid volume flow released by the fluid supply unit (24) and flowing into the emitter-receiver system (5) does not exceed a limiting volume flow QK.

Abstract: A known device for increasing the functional reliability for a hydraulic circuit of a hydraulic clutch having one pressure reservoir and one release cylinder which comprises a primary piston, a secondary piston and a compensation volume is to be further developed in the sense that when the vehicle is at a standstill and the parking brake released, an unintentional release of the clutch is prevented. According to the invention there is used for the purpose a pressure-monitoring/pressure-supply device (28) which determines a reference operating pressure and establishes a static pressure which in case of system errors allows only a displacement of the secondary piston (16) such that the contact pressure of the clutch discs against each other is still sufficient to hold the vehicle at a standstill.

Abstract: An operating time is determined by an approximation method within the scope of the method for determining the actual operating time of a hydraulic, electrohydraulic or electric component of a motor vehicle or of a working machine within a reference time or a monitoring period.

Abstract: A device for rendering a hydraulic actuating device operational. A motor vehicle clutch with an emitter-receiver system located in the transmission path of the actuating device comprising two pistons whose positions, relative to one another, can vary as a function of the desired operating behavior of the actuating device and is developed further such that in relation to the emitter-receiver system that is to be filled with fluid, operationality can be established comparatively quickly and by simple way. A fluid supply unit (24) comprises one impulse valve (25) that serves to release an essentially constant volume flow, acted upon by an impulse valve control device (26) which is constructed such that the fluid volume flow released by the fluid supply unit (24) and flowing into the emitter-receiver system (5) does not exceed a limiting volume flow QK.

Abstract: A method is proposed for determining a clutch application point in a transmission of a vehicle having a spring-actuated clutch system in which the clutch application point is adapted according to at least one adequate regulated quantity of the clutch system.

Abstract: An actual operating time is determined by an approximation method within the scope of the method for determining the actual operating time of a hydraulic, electrohydraulic or electric component of a motor vehicle or of a working machine within a reference time or a monitoring period.

Abstract: The invention relates to a method for controlling a pressure supply device in a hydraulic circuit, especially in a hydraulic circuit in an automatic gearbox which comprises an hydraulic pump, a pressure control valve and a consumer. The hydraulic pump is controlled if the system pressure falls below a specific lower threshold value and is switched off if a specific higher threshold value of the system pressure is reached or exceeded. In the data on the system pressure is not available, the current system pressure is calculated.

Abstract: A method for clutch actuation at low temperatures for a motor vehicle having a hydraulically actuatable clutch, below a predetermined temperature a situation-dependent pre-opening of the clutch is executed when a braking is probable.

Abstract: A double-action hydraulic cylinder (3) is provided with an axially slidable piston between a front cover and a rear cover, whereby the piston may be coupled to an extreme load through a piston rod (4) and whereby the piston may be biased via connections (5) for a hydraulic medium at both sides with the hydraulic medium from an extreme pressure source. The connections (5) are attached to the cylinder barrel (6) by means of soldered joints to achieve a good surface finish and thereby also an optically appealing appearance together with a reliable mounting of the pressure connections.

Abstract: An actuation arrangement for movable components on vehicles, particularly for trunk lids or hoods, doors, vehicle tops and top covers, including at least one hydraulic cylinder (1) pivotably coupled to a cylindrical pivot pin (11) on the vehicle and/or on the movable vehicle component, and having at least one line (1) for the pressure medium in at least one working chamber (6, 9) of the hydraulic cylinder.

Abstract: A double-action hydraulic cylinder (3) is provided with an axially slidable piston between a front cover and a rear cover, whereby the piston may be coupled to an extreme load through a piston rod (4) and whereby the piston may be biased via connections (5) for a hydraulic medium at both sides with the hydraulic medium from an extreme pressure source. The connections (5) are attached to the cylinder barrel (6) by means of soldered joints to achieve a good surface finish and thereby also an optically appealing appearance together with a reliable mounting of the pressure connections.

Abstract: An actuation arrangement for movable components on vehicles, particularly for trunk lids or hoods, doors, vehicle tops and top covers, including at least one hydraulic cylinder (1) pivotably coupled to a cylindrical pivot pin (11) on the vehicle and/or on the movable vehicle component, and having at least one line (1) for the pressure medium in at least one working chamber (6, 9) of the hydraulic cylinder. To allow pivoting of the hydraulic cylinder principally at any angle with low space requirements and a low risk of damage to the hydraulic lines, one section (16) of each pressure medium line passes through the pivot pin (11) essentially in an axial direction and at least one passage leads from the pivot pin (11) to at least one working chamber (6, 9) of the hydraulic cylinder (1).

Abstract: In a motor vehicle having a transmission (1) which can be optionally operated fully automatically or semi-automatically, and in which a gear-range selector (18) and a gear-shift control (21) are provided. The gear-range selector makes it possible to pre-select a travel speed in which the transmission is gradually shifted up or down by actuating the gear-shift control (21). The gear-shift control (21) is designed as a foot switch (22, 24) located in the foot area of a driver's cab of the motor vehicle, so that both of the driver's hands can stay on the steering wheel while these gear-shift operations are being carried out thereby permitting the driver to concentrate fully on the traffic.

Abstract: A shifting system used in combination with a motor-vehicle engine having an output connected via a clutch to the input of a multiratio transmission in turn having an output connected to a load comprises respective sensors for detecting the speeds of the motor output, transmission input, and transmission output and for generating outputs corresponding thereto, and respective clutch and transmission sensors for detecting the settings of the clutch and transmission and generating outputs corresponding thereto. A shifter element can move between an actuated position and an unactuated position. A double-display has a current-setting part and an ideal-setting part and is connected to a controller that is also connected to the sensors. This controller displays on the current-setting part the current setting of the transmission and on the ideal-setting part a setting calculated to be ideal based at least on engine characteristics and transmission output speed.