Hermann Hemscheidt Maschinenfabrik Gmbh & Co.

Dbt Gmbh

Dbt Deutsche Bergbau-technik Gmbh

Hermann Hemschedit Maschinenfabrik Gmbh & Co.

Other

Dbt Automation Gmbh

Hermann Hemscheidt Maschinenfabrik Gmbh

Hermann Henscheidt Maschinenfabrik Gmbh & Co.

Caterpillar Global Mining Europe Gmbh

Werner Reinelt

Karl Krieger

Wolfgang Kobow

Michael Dettmers

Franz-Heinrich Suilmann

Karl Krieger, Deceased

Guy Geuns

Friedrich Wilhelm Dannehl

Sebastian M Mundry

Jens Titschert

Patrick Hantke

Torsten Boldt

Jurgen Romanski

Jochem Hartleb

Willi Kuster

Horst Wagner

By Hildegard Krieger, Legal Representative

Holger Behnert

Friedrich-Wilhelm Dannehl

Gunter Kuschke

A water system for the admission of pressurized water to spray systems arranged on a powered support assembly for underground mining, having at least one spray system for plow or shearer track spraying and having at least one further spray system for goaf space spraying, canopy spraying and side spraying. A central water line feeds spray nozzles of the spray systems. To increase the operating reliability of the water system and thus of the powered support assembly, the control valves for the spray systems are accommodated in a spray valve block which is provided with a connection for the water line and which can be arranged on the powered support assembly as a unit separated from a hydraulic valve block.

Arrangement for the admission of pressurized water to spray systems

A hydraulic shield support is disclosed with at least two adjustable-length hydraulic props supporting a dedicated shield, which are connected through a control bank to a hydraulic fluid supply and borne on base shoes, and to which a pressure in excess of the pressure of the hydraulic fluid may be applied in the set condition of the shield support. In order to provide almost any pressure level at each shield support at a deep face in a simple way, the shield support has at least one pressure intensifier located in a hydraulic pipe system between the hydraulic fluid supply and the hydraulic props, with an oscillating intensifier piston in the form a differential piston effecting the increase in pressure. The low pressure inlet of the pressure intensifier is connected to the setting pressure pipes upstream, and its high-pressure outlet downstream, of a hydraulically-releasable non-return valve.

Hydraulic shield support

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. The information in the information element or transponder is readable by the reader unit and transmittable to the control unit. All the control valves and sensors are coded for the control unit and the control unit can associate each actuator with its corresponding control valve. In this way, it can be known which actuator is associated with which function of the hydraulic component and connection faults can be avoided.

Assembly for use in underground mining

A lift cylinder arrangement is disclosed for a hydraulic support frame for underground mining. The support frame has a lift cylinder for lifting the base shoes during advancing, which is supported on the one hand on a return rod and on the other hand, in a pivoting manner, with an end supporting head to a drawbar connected to the base shoes. In order to allow a simple, rapid and reliable connection between the supporting head and the drawbar, the supporting head is connected to the drawbar by a plug-type locking system comprising two plug-type locking elements, which include first locking notches on the drawbar, and arranged complementarily thereto second locking notches on the supporting head, whereby the plug-type locking elements engage in at least one of the locking notches with clearance.

Lift cylinder assembly

An electrohydraulic control device for use in the hydraulic systems of advancing support frames of underground mining equipment, which can be switched by means of switching plungers of electromagnets (), and the directional control valves () are put together from pilot control valve () and main control valves () arranged on a common axis, where by the pilot control valve () switches the main control valve () by means of a separate pressure medium supply to be found on an additional control pressure line, in which accepting borings () are suited for the acceptance of main control and pilot control valves () constructed as cartridges which are plugged together.

Electrohydraulic control device

A hydraulic cylinder ( ), especially as a pit prop or moving cylinder unit in underground mining, with a locking ring ( ) arranged on an outer cylinder tube ( ) sealing it at its end with a lead through for an axially movable rod element ( ) accommodated in it. The locking ring ( ) is provided in the lead through surrounding the rod element ( ) with a sealing arrangement ( ) resting on the outer side ( ) of the rod element ( ). The sealing arrangement ( ) has a guide ring ( ) provided with grease grooves ( ) open to the outer side ( ) of the rod element ( ), which can, be supplied with lubricant for the grease grooves ( ) via a lubricant line ( ) accessible on the outside on the hydraulic cylinder ( ) and which is arranged in an accepting groove ( ) formed interlocking ring ( ) between an axially inner and an axially outer collar ( ). The gap ( ) formed between the outer collar ( ) and the rod element ( ) is greater than the gap ( ) between the rod element (( ) and the inner collar ( ) and that the guide ring ( ) is arranged axially inside adjacent to an axial further outward lying O-ring seal ( ).

Hydraulic cylinder

In the directional control valve ( ) for support mechanisms in underground mining, the valve piston ( ) is guided seal free in the valve seat carrier ( ) between the high pressure connection (P) and a sealing ring ( ) and thus permits an overflow of high pressure fluid from the high pressure connection (P) to the return flow connection (T) on opening the valve ( ). The valve ( ) thus achieves an opening and closing characteristic with negative overlapping and so provides gentle switching processes, so that switching impacts with high pressure peaks do not arise.

Hydraulically operated directional control valve

A valve arrangement ( ) for hydraulically actuated machinery installations, especially for powered support assemblies in underground mining, with hydraulically actuated working valves ( ) to control hydraulic cylinders ( ) or other hydraulically actuated machinery units of the machinery installation and with pilot valves ( ) controlling the working valves. In order to avoid the pilot valves ( ) and working valves ( ) entering an unstable operating condition in the event of a falling off of pressure in the hydraulic fluid supply to the valves, and opening and closing in an uncontrollable and undesired manner, the pilot valves ( ) are attached to their own pressure medium supply ( ), separate or separable from the hydraulic fluid supply ( ) to the working valves ( ), so that pressure variations in the hydraulic fluid supply circuit do not affect the pressure medium for the switching of the working valves ( ), but the pressure in them is maintained largely constant.

Valve arrangement

The double telescopic prop comprises an outer cylindrical casing tube,, an inner tube,which is displaceable therein and a piston rod,which can be extended therefrom. The hydraulic fluid for extending the two prop stages is conveyed through a connection,to the piston,of the inner tube,and is conveyed via a bottom valve to the piston,of the piston rod,. The prop is retracted if hydraulic fluid flows via the connection,into the outer annulus,between the cylindrical casing tube,and the inner tube,. A size ratio of 8.8:1 at most, which is favourable for the retraction of the prop, exists between the area of the inner tube,and the ring area of the annulus

Hydraulic double telescopic prop

Electrohydraulic control valve

The body (1) of the hydraulically trippable check valve for mine support hydraulics according to the invention contains: a valve poppet (13) biased in the closing direction by a spring (22); a control piston (17) which can be acted on by a hydraulic control pressure, causing the poppet (13) to be lifted off its seat (11); and an initial relief valve (20, 21) which can be tripped by the control piston (17) against its spring closing force. Matters are arranged so that the control piston (17) which can be acted on by the hydraulic control pressure is dimensioned in terms of piston surface area (17') so that the poppet (13) of the check valve cannot be lifted off its seat (11) until the opening of the initial relief valve has caused a predetermined initial relief of operating pressure on the high-pressure side. The result is a hydraulically pilot-controlled check valve which has high operational reliability and in which harmful oscillation or chatter of the valve poppet (13) of the check valve and/or control piston (17) cannot occur.

Hydraulically trippable check valve for underground mine support

The control device is adapted to be inserted between the control valves of a pilot device and the pressure-medium consumers (hydraulic prop and hydraulic working cylinder) in an hydraulic self-advancing mine-roof support and is connected to a pressure-medium line and to a return line. The control device comprises a valve block with continuous longitudinal bores for connection to a multiple tubing line leading to the pilot device, the valve block having bores for receiving piloted 3/2-way valves and bores for connection to the directly-controlled working cylinders of the mine-roof support.

Control device for mine-roof support

A method of working coal seams to a defined preset cutting depth during ploughing with a cutter, a face conveyor moving along a face behind the cutter being advanced by the defined preset cutting depth and this advance being made by extension of self-advancing cylinders pivotally attached at one end to the face conveyor and at the other end to face supports disposed parallel to the face conveyor. The advance is controlled in dependence upon the piston stroke of the self-advancing cylinders, carried out in dependence upon individually defined partial strokes corresponding to the preset depth of cutting. After a predetermined maximum total piston stroke has been reached, the face support connected to the respective self-advancing cylinder is automatically disengaged, advanced by the maximum total piston stroke and then re-set (self-advancing process). The length of the partial strokes corresponding to the preset depth of cutting is increased by an amount to compensate an average mechanical clearance at the pivot points of the self-advancing cylinders.

Method of working coal seams to a defined preset depth of cutting during

A control system for longwall face support frames as used in mines, the system comprising pushing rams which are adapted to be actuated at two different pressures (for example, a low pressure of about 70 to 120 bar for non-defined cutting and a high pressure of 120 to 350 bar for defined cutting) with each pushing ram being individually actuatable by a respective non-return valve arrangement, the pushing rams being connected by a common pressure line to an hydraulic pressure unit.

Control system for longwall face support frames

A 2-port, 2-directional hydraulic valve is disposed alongside a pulse generator in a casing, the actuating force of the pulse generator being transmitted to a push rod of the valve for actuating the latter via a two-armed lever mounted like the beam of a balance. A threaded bore in one lever arm receives a bush which is adjustable in the direction of actuation and contains a spring-loaded pressure member. A set screw can be used to pre-stress the spring and thus exactly adjust the transmitted actuating force, while the adjustable bush is used for pre-setting the actuating travel.

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Bochum, Germany

Werner Reinelt