Abstract: Both improved protection against explosions and the possibility of performing diagnoses even when the I/P converter has been disconnected are to be provided by a position controller (5) for a pressure medium-operated actuating system, the controller being designed to be connected by a pneumatic line to a pneumatic drive (4)-equipped actuator (1) of an actuating element, especially an actuating element of a safety valve (2), where the actuator (1) has an electric power line (6) for controlling an I/P converter (7) according to the live-zero principle, and where the I/P converter (7) can be driven by an electrically controlled switch (10). The goal is achieved in that the switch (10) is designed to be driven by an additional circuit (11), which is connected to the power line (6) and installed in the position controller and which monitors the current in the power line (6).

Abstract: The invention relates to a method for monitoring the functionality of an actuator (1) having a pneumatic drive (2), in particular for monitoring an actuator (1) for a safety valve, including a magnetic valve (4) for controlling the pneumatic drive (2), wherein the magnetic valve (4) is monitored by means of a pressure measurement and is, for this purpose, connected to a first pneumatic conduit (16) to a position controller (3) of the actuator (1) as well as to the pneumatic drive (2) to a second pneumatic conduit (17). The magnetic valve (4) is switched off and on again with a switching time (t2?t1).

Abstract: The invention pertains to a sealing arrangement 10, 10a, which acts between a housing 12 and a component 14 installed in the housing 12, with a stop 16, permanently connected to the housing 12; with a spring 20, which is supported on the stop 16; and, with at least one first sealing element 22 in working connection with the spring 20. Abutment 34 is designed to be adjusted against the force of the spring such that the spring 20 is completely compressed—squeezed into a block—and additional load can be exerted on the sealing element 22, so that in particular any leakage which has developed can be stopped—on an emergency basis—by the exertion of additional load on the sealing element 22, which has the effect of increasing the sealing force which the sealing element 22 exerts.

Abstract: In a method for testing the functionality of an actuator in an actuating system, especially for the actuator of a valve (2) in a safety-oriented circuit in which the partial stroke test method is used, where the actuator is moved briefly by its drive element (8) such as a valve rod over a portion of its actuating path to test its functionality, the goal is to prevent the actuating system from closing too far during the performance of the partial stroke test method. This is accomplished in that, to prevent the actuating system from closing too far, the drive element (8) with the actuator is driven in such a way that it can be moved only within permitted limits during the partial stroke test. The actuating path of the actuator (7, 8) is limited by a mechanical stop (15).

Abstract: The invention pertains to a field unit (10) for mounting on an actuator (12) with a pickup device (14) in the field unit (10) to register the position of the actuator (12) and with an indicator (16) located correspondingly on a movable element (15) of the actuator (12) to indicate the position of the actuator (12), where, when the field unit (10) is mounted on the actuator (14), the pickup device (14) of the field unit (10) can be linked with the indicator (16) of the actuator (12). The invention is characterized in that the pickup device (14) of the field unit (10) is in working connection with a locking element (18), and in that the pickup device (14) can be held by this locking element (18) in a first position—the mounting position—and can be released from the mounting position by the actuation of the locking element (18).

Abstract: A method for monitoring a the contact resistance (Rs) of the wiper of a sensor for a variable quantity, with a potentiometer (2), in which the position of the center tap (3) determines the value of the quantity, is improved in such a way that, first, when the sensor is used in an automatic control circuit, no control deviations occur and, second, the contact resistance of the wiper can be monitored with precision. This is achieved by the cyclic switching-on of a load (RLast), so that the contact resistance (Rs) of the wiper can be determined on the basis of the change in the voltage divider ratio.

Abstract: The invention pertains to a method for verifying the performance of a test of the functionality of an actuator (1) with a drive (2) and a valve (3a), where the valve (3a) can be moved by the drive (2), which uses a drive element (3) acting on the valve (3a); where the drive element (3) and thus the actuating element of the valve can be moved by means of a position controller (5) over a portion of the actuating distance to perform the partial-stroke freedom-of-movement test and thus to test the functionality of the actuator (1), and where the position controller (5) has a distance sensor (7)—the primary sensor—and a first evaluation unit (8) for evaluating and storing the signals of the distance sensor (7).

Abstract: The invention pertains to a device for the controlling the position of a pneumatic actuator comprising: a pneumatically adjustable actuating element (5); a pneumatic actuating drive (6) for adjusting the actuating element (5); an electro-pneumatic position controller (1) for pneumatically driving the actuating drive (6) as a function of a position controller set point and a controlled variable; and at least one main pneumatic power amplifier (10) with bypass throttle for amplifying the power output of the position controller (1) and for pneumatically driving the actuating drive (6). In addition, a pilot control pneumatic power amplifier (9) with a bypass throttle for preamplifying the pneumatic power output of the position controller (1) is installed between the position controller (1) and the main power amplifier (10).

Abstract: Both improved protection against explosions and the possibility of performing diagnoses even when the I/P converter has been disconnected are to be provided by a position controller 5 for a pressure medium-operated actuating system, the controller being designed to be connected by a pneumatic line to a pneumatic drive 4-equipped actuator 1 of an actuating element, especially an actuating element of a safety valve 2, where the actuator 1 has an electric power line 6 for controlling an I/P converter 7 according to the live-zero principle, and where the I/P converter 7 can be driven by an electrically controlled switch 10. The goal is achieved in that the switch 10 is designed to be driven by an additional circuit 11, which is connected to the power line 6 and installed in the position controller and which monitors the current in the power line 6.

Abstract: The invention pertains to a method for verifying the performance of a test of the functionality of an actuator (1) with a drive (2) and a valve (3a), where the valve (3a) can be moved by the drive (2), which uses a drive element (3) acting on the valve (3a); where the drive element (3) and thus the actuating element of the valve can be moved by means of a position controller (5) over a portion of the actuating distance to perform the partial-stroke freedom-of-movement test and thus to test the functionality of the actuator (1), and where the position controller (5) has a distance sensor (7)—the primary sensor—and a first evaluation unit (8) for evaluating and storing the signals of the distance sensor (7).

Abstract: In a method for testing the functionality of an actuator in an actuating system, especially for the actuator of a valve (2) in a safety-oriented circuit in which the partial stroke test method is used, where the actuator is moved briefly by its drive element (8) such as a valve rod over a portion of its actuating path to test its functionality, the goal is to prevent the actuating system from closing too far during the performance of the partial stroke test method. This is accomplished in that, to prevent the actuating system from closing too far, the drive element (8) with the actuator is driven in such a way that it can be moved only within permitted limits during the partial stroke test. The actuating path of the actuator (7, 8) is limited by a mechanical stop (15).

Abstract: The invention pertains to a field unit (10) for mounting on an actuator (12) with a pickup device (14) in the field unit (10) to register the position of the actuator (12) and with an indicator (16) located correspondingly on a movable element (15) of the actuator (12) to indicate the position of the actuator (12), where, when the field unit (10) is mounted on the actuator (14), the pickup device (14) of the field unit (10) can be linked with the indicator (16) of the actuator (12). The invention is characterized in that the pickup device (14) of the field unit (10) is in working connection with a locking element (18), and in that the pickup device (14) can be held by this locking element (18) in a first position—the mounting position—and can be released from the mounting position by the actuation of the locking element (18).

Abstract: A method for monitoring a the contact resistance (Rs) of the wiper of a sensor for a variable quantity, with a potentiometer (2), in which the position of the center tap (3) determines the value of the quantity, is improved in such a way that, first, when the sensor is used in an automatic control circuit, no control deviations occur and, second, the contact resistance of the wiper can be monitored with precision. This is achieved by the cyclic switching-on of a load (RLast), so that the contact resistance (Rs) of the wiper can be determined on the basis of the change in the voltage divider ratio.

Abstract: The invention pertains to a sealing arrangement 10, 10a, which acts between a housing 12 and a component 14 installed in the housing 12, with a stop 16, permanently connected to the housing 12; with a spring 20, which is supported on the stop 16; with at least one first sealing element 22 in working connection with the spring 20; and with an abutment 24, 34, which cooperates with the side of the sealing element 22 facing away from the spring 20 and which is permanently connected to the housing 12, where the sealing element 22, by virtue of the force of the spring, presses against certain areas of the housing 12 and the component 14, so that a sealing action is created extending from the front to the rear of the housing 12 and of the component 14.

Abstract: An input circuit for a field device for communication with bidirectional signals superposed on an analog signal, the input circuit being part of a current loop, supplies the field device with energy and simultaneously carries an analog current signal for prescribing a reference value. The field device is connected to an actuator that is suitable for achieving the reference value, and the input circuit has a voltage limiter, a shunt resistor and an inductance connected in series between its input and output. The input signal of an analog-to-digital converter can be taken at the shunt resistor. The voltage limiter is connected in parallel with a voltage regulator. The inductance is coupled via a capacitance to a reception unit and/or to a transmission unit for digital signals.

Abstract: A pressure controlled cutter bit or drill bit retainer in the form of a revolving drill head with hydraulic precision adjustment of the drill bit arranged at a central extension, which is displaceable from its original position by small amounts around a pivot axis by a pressure motor, wherein this displacement occurs without any parts mechanically rubbing against each other and the dimensioning of the pressure motor and extension defining the transmission ratio conditions are selected in such a way that the travel of the drill bit guided along a curved path is greater than the travel of the pressure motor output produced by volume change, and wherein the overall volume of the pressure motor is selected to be slightly greater than the volume required for moving the pressure motor output.

Abstract: Electropneumatic position controller having two solenoid operated pneumatic valves, each of which is respectively provided with a regulating pressure nozzle, an exhaust nozzle, a discharge line leading to a power amplifier, and a hinged armature that is driven by an electromagnetic system and alternatively closes the regulating pressure nozzle or the exhaust nozzle, characterized in that the solenoid valves each respectively comprise a channel that communicates with their exhaust nozzle and can be manually closed, the respective power amplifier being capable of being switched as a result of the closing of said channel even without electrical excitation of the magnet system.

Abstract: A cutting chisel holder which is controlled by pressure and constructed as a rotary drill head which can be precisely adjusted by hydraulic means has a cutting chisel, which can be clamped in, with a base and a driven member which is movable relative to the base, and has a pressure chamber arranged between the base and driven member, as well as a pressure medium feed. The driven member moves parallel to itself under the influence of the pressure medium and, in doing so, causes a movement of the cutting chisel on a curved path extending approximately vertically to the axis of rotation of the drill head by parts acting mechanically without friction.

Abstract: Rotating drill head with a boring bar which is swivel able by small amounts transversely to the rotational axis by fluidic means, with a base, a driven member located opposite the base, a pressure chamber arranged between the base and driven member and having a fluid inlet, and with an expanding lever gearing in a working connection with the driven member and serving for the synchronous and oppositely directed swiveling of a tool carrier and a compensating member which are constructed so as to be geometrically similar and constitute the boring bar.

Abstract: A method and an apparatus for determining the dimensional accuracy of workpiece surfaces, for example, of essentially cylindrical workpiece surfaces, wherein a measuring sensor scans the workpiece surfaces in accordance with a predetermined relative movement pattern between sensor and workpiece. The sensor is a pneumatic measuring head, so that the measuring procedure can be incorporated in the production process. The pneumatic measuring head travels over the workpiece surface along a continuous path which covers the surface area of the workpiece. The pneumatic measuring head is maintained at a constant basic or measuring distance from the workpiece surface, so that the measuring range of the measuring head is not exceeded when the measuring head travels over the workpiece surface. The measuring head continuously produces measurement signals, so that the measure procedure can be directly integrated in the production sequence.