Abstract: The pressure cell device according to the invention serves for measuring hydraulic pressures in hydraulic mining devices in an inherently secure service region. It is provided with a connection element which can be connected to a pressure reception connection and with a sensor housing, on the inside of which is arranged a hydroelectric pressure transducer which is pressurised by the hydraulic pressure present at the pressure reception connection and converts this into an electrical signal. So as to ensure high measurement accuracy over a long operating period, without it being necessary to have exchanges of the pressure transducer or its new calibration, it is provided according to the invention that the pressure transducer comprises a ceramic pressure measuring cell.

Abstract: The present invention relates to a method for operation of an electro-magnet (2, 3) connected to an intrinsically safe direct current circuit which can be switched under control between two positions for the operation of the closing body of a hydraulic valve (5, 6), whereby using of an electronic control unit, the coil windings of the electro-magnet (2, 3) are taken in the pull-in phase of the armature of the electro-magnet to an exciting current and in the retaining phase of the armature to a lower retaining current as opposed to the excitating current, and a device with which the retaining current reduction is realized.

Abstract: The invention relates to a connector for a cable for underground mining, comprising a socket part 1 and a plug part axially insertable into the socket part and having a hole in the back for inserting a cable, the plug part being secured to the socket part 1 by a screw cap 20 mounted for rotation on the plug part 10 and screwable on to an external thread 6 on the socket part 1 and being sealed against penetration of moisture and/or dirt by at least one sealing element. In order to obtain standard parts for a family of plugs by a simple assembly process and with maximum sealing-tightness against moisture and dirt and at low production costs, the plugs being suitable for inserting the cable either coaxially or radially, the external thread 6 on the socket part 1 and the associated internal thread 21 on the screw cap 20 are triple threads and/or a crown part 40 with at least one radial recess 41 for receiving the cable 30 is provided on the cable entry hole 18 on the back of the plug part. (FIG.

Abstract: The present invention relates to a pilot control valve, especially for use in mining hydraulics. The valve has a valve insert constructed as a valve cartridge, whose single or multipart valve housing has an input entry 17 for pressure fluid P, a connection opening 18 for a load connection A, an output opening 19, opening into the return flow T and an axial boring 21 to accept a valve closing body 20 provided with a closing surface, which can be lifted from a valve sealing seat 31 arranged between the entry opening 17 and the connection opening 18 by means of an electro-magnetic or piezo-electric switching device which can be fastened onto the valve housing. With the lifting movement of the valve closing body 20 from the valve sealing seat 31 is coupled an at least two part closing mechanism for their separation arranged between the connection opening 18 and the output opening 19.

Abstract: The invention relates to a mining electromagnet for the switching of hydraulic pilot valves or main control valves used in underground mining operations, with a coil which can be connected to an intrinsically-safe power unit, with an armature which can be displaced by application of current to the coil and with an electronic control device 20, by means of which the current which is conducted to the coil can be set during the drawing-in phase of the armature to an excitation current, and in its holding phase can be set to a holding current which is lower than the excitation current.

Abstract: Longwall face equipment for use in extraction in underground mining, comprising electrohydraulically operated support units each having a support controller 6, with at least one power unit being provided that supplies at least two support controllers 6 of differing support units with power, and with a bi-directional coupler being connected between the power unit and the at least two support controllers 6 and providing galvanic isolation between the power unit and the support controllers 6 and/or groups I, II of support controllers 6. The couplers permit communication between the two support controllers 6 and/or groups I, II of support controllers. In order to simplify the arrangement of the face, the coupler 12 is integrated into the power unit 11 or is flanged directly onto the housing of the power unit.

Abstract: A method and a circuit arrangement (10) for the measurement of earth leakage in intrinsically safe current feeds to electronic control units (4) for underground mining installations and machines, whereby at least one earthed control unit is connected to the two intrinsically safe potentials of an intrinsically safe direct current supply (1) and at least one earth leakage sensor (20) is provided for earth leakage measurement with which steps of the periodical application of a test potential (Umess) from an intrinsically safe switchable test voltage source (21) to an RC-element (22), isolated from earth (8) by means of decoupling capacitors (C1, C2), measurement of the charging or discharging current behaviour of the RC-element (22) after each switching of the test voltage source (21) and comparison of the measured charging or discharging behaviour with stored reference data.

Abstract: A controller is disclosed for control operations in underground mining, especially for controllers to control support shields. The controller utilizes a central unit with a microprocessor and assigned, programmable memory devices for the storage and processing of software as well as a connector unit with connectors or circuits for communication between the controller and other controllers and/or actuators, sensors or the like, that are to be controlled with the controller. Both the central unit and the connector unit utilize a modular design. A collection of modules with different performances and/or functionalities are provided for both the central unit and the connector unit to form the hardware of a controller. The modules can be combined with one another and coupled together according to a modular concept.

Abstract: An electro-hydraulic assembly for use in underground mining is disclosed. The assembly includes a hydraulic component, such as a valve block for an underground self-advancing roof support, as well as actuators and/or sensors which have a housing and can be connected or are connected via a data-transmission system to a control unit. A function (e.g. withdrawing the support, setting, advancing, or the like) can be activated at the hydraulic component by each actuator, and/or a hydraulic state associated with a measuring point of the hydraulic component or another measured variable associated with the self-advancing roof support can be measured by each sensor. A reader unit is associated with each actuator and/or sensor in its respective housing, and an information element or transponder is associated with the hydraulic component for each function, each control valve, or each measuring point.

Abstract: Disclosed is a face support control system as used in conjunction with an underground mining system. The mining system generally includes a mining machine, a conveyor, one or more support shields, an array of control devices for controlling the operation of the support shields, one or more communication devices in communication with the support shields, and a face master control. The control system utilizes radio communication between the communication devices and the face master control.

Abstract: The warning tone transmitter (10) according to the invention has a piezoelectric horn element (12) with two input connectors (29, 30) for the application of the supply voltage at a determined frequency and has a circuit arrangement (14) fed from the current supply, which generates the supply voltage. In order to be able to receive confirmation that the horn signal is actually generated by the warning tone transmitter (10) and in order to be able more easily to calibrate the warning tone transmitter (10) such that it is driven at its resonant frequency the piezoelectric horn element (12) has an additional output connector (34), which, when the horn element (12) is fed with the supply voltage, generates an answering signal taken to the circuit arrangement (14) if the piezoelement is actually oscillating. The magnitude of the answering signal is a value for the sound volume of the warning tone transmitter (10).

Abstract: The invention relates to a method for the control of the chain drive mechanisms of underground working machines and a correspondingly equipped chain scraper conveyor. The invention proposes to filter out a detection signal (Serk), representative of the currently arising vibrations of the chain (1), from the operating data of the main and auxiliary drives (I, II) by means of a detection device (34), and to take this to an active suppressor (35), which generates a time-variable control signal (STilgung) in accordance with a suppressor function, with which, in the frequency range of the vibration of the chain, a change is effected to a control value, e.g. (Ssoll) for the closing pressure adjustment of a multiple disc clutch (6) of at least one drive unit for the suppression of vibration by the abstraction of energy from, or the introduction of energy into the chain (1).

Abstract: The invention relates to a plug-in cable connector 3 for electrical cable or plug connections 10. The cable connector 3, which forms the termination of the cable 1, has a hollow connector shell 4 of brass, whose boring forms a cable entry opening on its cable side section and an abutment collar 5 on which a plug connector 6 with a collar 6′ is supported axially in one direction. The cable entry opening is provided with an internal thread 22, in which a four cornered part 30 of metal, having a through boring 35 for the cable, is screwed in. The screening or armouring of the cable 1 can be accepted between the through boring 25 and the cable covering 1′, so that a good earthing of the cable 1 and the cable connector 3 can be achieved. The interior space of the connector shell 4 is sealed by means of a formed part 27, which is formed onto the cable covering 1′, the connector shell 4 and the multi-cornered part 30.

Abstract: A control device (10) for electro-hydraulic support frames with a casing (11) accommodating a circuit, several plug-in connectors (20) accessible from outside the casing (11) for the connection of control leads, and with actuating control elements (13) connected to the circuit. The control elements (14, 15, 16, 17, 18) are grouped together in several exchangeable modules (27), accommodated in the casing (11), which are connected to the circuit and to each other by plug-in connecting elements (30) when installed in the casing (11). The modules (27) are exchangeable independently of each other. The operating keys of a keyboard (16) and/or an indicator unit (18) can be combined in one operating module (28), which can be removed from the casing (11). The actual control of the control device in the casing (11) and operation of the support frame is permitted to continue during the exchange of the operating module (28).

Abstract: A method and apparatus for remotely controlled operation of one of several control devices (13) for support frames in underground mining in which the control device (13′) to be actuated is selected by means of an infra-red remote operation and then the transmission of control data between a remote controller (16) and the selected control device (13) is effected by radio transmission. The remote controller, (16) has not only a radio transmitter (18) and the control devices (13) a radio receiver (15), but each control device (13) is additionally provided with at least one infra-red receiver (20), whereby by an infra-red data transmission, the control device (13′) to be actuated is first deliberately selected by the remote controller (16), before the control data is then subsequently transmitted by radio.

Abstract: A method and a device for use in underground mining for the detection of the presence of persons at mine faces supported by support frames, whereby detection sensors (25) are provided on at least some of the support frames (10), and which are coupled to control units (27) for the support frames (10), whereby the detection sensors (25) sample the working and operating area (24) of the associated support frame (10) and bring the latter to a standstill in its movement sequence, if the detection sensors (25) detect the presence of a person in a detection area (30). In accordance with the invention the detection sensors (25) of the individual support frames (10) can be switched on and off by the control units (27) and are only activated when the associated support frame (10) is to be moved and are again de-activated after completion of the movement of the associated support frame (10).

Abstract: The invention relates to a plug-type coupling for sheathed electrical cables, particularly for use in mining, with a flexible protective sheath which accommodates electrical conductors of the cable. The end of the sheath is gripped in a pullproof and sealed fashion between a pressed sleeve which surrounds it and an inner backing sleeve, these parts forming part of the coupling which also includes a coupling sleeve which adjoins the pressed sleeve and receives an insert which holds contact elements electrically connected to the electrical conductors. According to the invention, the pressed sleeve is joined to the coupling sleeve to form a one-piece connector to which the insert carrying the contact elements can be coupled in a pullproof fashion by means of a snap connection. The distinctive features of the sheathed cable coupling according to the invention are simplicity of construction, ease of assembly and low production cost.

Abstract: Pressure sensor (10) for measuring hydraulic pressures, in particular for use in mining hydraulics, having a hydraulic connection (12) and a hydraulo-electrical pressure transducer (15) which is loaded hydraulically via the said connection, and having a circuit board (18) which processes the electrical measured values from the pressure transducer. In order to ensure a secure fastening of the circuit board to the pressure transducer with, at the same time, easy exchangeability of the board, it is proposed by the invention that the circuit board be screwed to the pressure sensor (10) at a distance from the pressure transducer (15), preferably with at least one spacer (23, 24) interposed.

Abstract: The electrohydraulic control unit comprises at least one 3/2 directional control valve 2 which is switched by an electromagnet 3 connected to an intrinsically safe power supply. The components of the 3/2 directional control valve 2 are arranged in a valve cartridge 18 inserted into the valve casing 1 on a common axis and with adjustable clearance with respect to the electromagnet 3. The control plunger 12 of the electromagnet 3 transmits the switching force through a precompressed spring buffer 4 to the stoppers 24, 30 of the 3/2 directional control valve 2.

Abstract: A cable for connecting control units of powered supports to each other to prevent simultaneous movement of two adjacent powered supports in underground mining. The cable includes plug housings, at least one optical waveguide, connecting elements, optoelectric transducers, and potting. Each housing contains a chamber and has an electric plug-in coupling that connects to the control units. The at least one optical waveguide has ends with light entry and light exit surfaces. The connecting elements are arranged at the ends of the at least one optical waveguide and are arranged in the chamber in a respective plug housing. The optoelectric transducers are connected to the connecting elements and are arranged in the chamber of the respective plug housing and transmit data between the control units.