Control method of drum actuating element

FIELD: mining.

SUBSTANCE: in control method of drum actuating element equipped at least with one lever of drum actuating element each electric hydraulic section of the support is equipped with its own electric hydraulic control instrument. Control commands are entered for correction of lever position of drum actuating element from control instrument of support section. And they are supplied from there to control system of drum actuating element.

EFFECT: improving control efficiency of the cut by means of drum actuating element.

8 cl

 

The present invention relates to a method of controlling the drum by the Executive body, provided with at least one lever drum Executive body in the lava with electro-hydraulic shields, each shield section is equipped with its electro-hydraulic control unit.

In the known methods of learning drum Executive body of such first makes learning a passage in which prescribed the desired horizon cut, and then this pre-programmed passage is repeated. To control the cut with a drum of the Executive body of the miner tries to follow the drum by the Executive body and to compensate for possible deviations from the adjustment control commands drum by the Executive body.

The problem here is, on the one hand, that drum Executive bodies can achieve a velocity of 20 meters per minute, while the miner with thin flat layers can only move at a speed of about 5 meters per minute. In addition, the promotion is complicated by the fact that the miner to supply to the system control drum of the Executive bodies in order correction further control commands forced to have an input device.

Another problem is mA is in the error control in relation to the horizon drum Executive body having a large number of coal in mined-out space, as the miner often does not control or no control of the notch lying on its side. However, because of the presence of the notch in the developed space large quantities of coal have a substantial number of spontaneously igniting coal, which is undesirable.

The task of the invention is to improve the way management section supports the above type that has been improved control over the cut with a drum of the Executive body.

The solution to this problem is using the characteristics of paragraph 1 of the claims so that control commands to adjust the position of the cutting lever or levers drum of the Executive body, are the respective device control shield section, and thence transmitted to the control system of the drum by the Executive body.

With the method according to the invention it is no longer necessary for the operator to drum the Executive body had a control of the shield section for inputting control commands to correct the position of the lever drum of the Executive body, i.e. to correct the cut on hanging and lying b is Kah. Moreover, all control commands are entered directly into the electro-hydraulic control devices are available in each of the shields. Corrective commands are transmitted from the corresponding control unit in the control system of the drum by the Executive body, so that it may be produced by a corresponding correction of the position of the levers drum of the Executive body.

Furthermore, the method according to the invention provides that the control is not carried out by only one operator drum of the Executive body, and in order to control the movement of the drum along the lava was used a few miners, and to each miner was responsible for the plot of lava, for example 15-20 shields, and controlled rez as hanging and lying on its side. In this case, the required amendments miner can enter control commands from the control unit of the relevant sections of the support, with no need to transfer the control of the shield section from one miner to another.

The control unit corresponding section of the lining may be associated with the Central device of the educational amendments of arrival is sent to the system control drum by the Executive body. The place where you want to adjust the position of the levers Baraba is the main Executive body, it is known from the location of the respective device control, ie, for example, from the address of the electrohydraulic control unit shield section. In this case, the address of each control unit shield section or number, or symbol represents the location information of the device management section of the lining, so that the control system drum Executive body know where along the lava must be made the appropriate correction.

Control signals from the control unit it is possible to transmit to the Central control device, and wirelessly directly to the control system of the drum by the Executive body.

In one embodiment of the invention, several, for example 15-20, adjacent sections of the lining can be summarized in a single management group, controlled by the Central control device. Thus, each local supervising the miner is given its own management group.

For quick input of control commands, the control devices can be programmed in such a way that they to enter control commands were input mask. This input mask can be indicated, at least those control devices shields, in the area where the drum IV is positive the body is at the moment, i.e. those control devices by which the drum of the Executive body as time passes or performed.

To avoid erroneous entries may be preferable to the input mask for entering control commands were indesirable only those controls shields, in the area where the drum is at the moment.

1. The method of controlling the drum by the Executive body, provided with at least one lever drum Executive body in the lava with electro-hydraulic shields, each shield section is equipped with its electro-hydraulic control unit, wherein the control commands to adjust the position of the lever drum Executive body is injected with the control of the shield section, and from there transmitted to the control system of the drum by the Executive body.

2. The method according to claim 1, characterized in that the control system drum Executive body receives information about the location of the device management section of the lining, and the control system drum Executive body carries out the correction depending on the position of the drum of the Executive body at the moment.

3. The method according to claim 1 or 2, characterized in that the control commands are passed from the control of the shield section to the Central unit, and is there - in the control system of the drum by the Executive body.

4. The method according to claim 1 or 2, characterized in that the control commands from the control of the shield section is passed to the control system drum Executive authority on wireless.

5. The method according to claim 1, characterized in that several neighboring, such as about 15-25, shields reduce one management group, controlled by the Central control device.

6. The method according to claim 1, characterized in that the input mask for entering control signals indicate at least the controls section of the roof support on the site which drum the Executive body is at the moment.

7. The method according to claim 1, characterized in that the input mask for entering control signals indicate only those control devices shield section, the section which drum is the Executive body at the moment.

8. The method according to claim 1, characterized in that the control commands are entered several miners, each miner controls the area of the lava with a certain number of neighboring shields.



 

Same patents:

FIELD: mining.

SUBSTANCE: extraction device of coal in longwall face of underground mine working consists of the following: many sections of powered support, which are installed near each other throughout the length of longwall face between gates; plough machine; chute and conveyor located in it with possibility of movement, which are located throughout the length of longwall face between extraction machine and support sections; several deflecting devices and control device. Plough machine is provided with possibility of being moved along the line of the mining face and equipped with rock detection sensor which is provided with possibility of transmitting radio data of the detected rock to the control device of the support by means of the transmitter installed on the plough and the radio receivers installed along the longwall face. Group of adjacent support sections and sections of the chute corresponds to each deflecting device. Deflecting device is connected to control unit of one of the support sections of the appropriate group, and depending on the data of the detected rock, it provides the possibility of lifting the chute sections of the appropriate group, which is accompanied with lowering of the tools of the plough machine, and lowering of the chute sections, which is accompanied with lifting of plough machine tools. Control device includes the following: bottomhole control unit located at the end of longwall face for control of functions of support sections in relation to unloading, transportation and bracing of the support; control units of sections, each of which is put into spatial and functional compliance with the appropriate support section for performing and further transmitting the commands from bottomhole control unit; and the bus connecting mainly in series the bottomhole control unit to control units of support sections. At that, rock sensor when moving beside each support section is provided with possibility of generating the measurement signal characterising the detected rock only for several, mainly not more than two measurement points. Measurement signals received at neighbouring measurement points are subject to analysis with a view to predominance of rock or coal. Depending on analysis results, there generated is deviation signal supplied to the common deflecting device common for all measurement points, and namely to the deflection of the chute sections, which causes the lifting of plough machine tools if analysis results show the predominance of rock at the analysed measurement points, and to deflection of the chute sections, which causes the lowering of the plough machine tools if the analysis results show coal predominance at the analysed measurement points.

EFFECT: possible quick correction of the plough machine position during the coal extraction, which causes the lifting and lowering of the plough.

9 cl, 2 dwg

FIELD: mining.

SUBSTANCE: equipment consists of electric-hydraulic driven sections of lining with corresponding facility for lining control. Additionally, there is foreseen at least one doubled block of power source, which provides current for at least two means of lining control of different sections of lining independently from each other. A double-sided element of communication is installed between the power source block and at least two means of lining control; this element performs galvanic separation between the power source block and means of lining control and/or groups of means of lining control. Also the element of communication forms a galvanic separated data transmitting channel which facilitates communicating between two means of lining control and/or groups of means of lining control. Notably, double-sided element of communication is in-built into the power source block or is flange mounted directly on the case of power source block.

EFFECT: simplification of design of face equipment.

4 cl, 2 dwg

FIELD: mining.

SUBSTANCE: invention relates to control system over underground face support with transport. The control system for underground walking face support consists of transporter, winning machine, plurality of panels each equipped with a block of functional control with a corresponding panel, of a facility connecting control blocks between themselves, of a central station located outside long wall face and communicating means for transmitting data between control blocks in the long wall face and the central station outside long wall face. The communicating means include at least one radio transmitting device from the side of the long wall face and one radio transmitting device from the side of the central station with receiving and transmitting modules to facilitate wireless and cable less two-directional data transmitting at the long wall face end.

EFFECT: minimisation of costs for cable laying for underground control system over face support and increase of reliability of face support control.

7 cl, 2 dwg

FIELD: mining.

SUBSTANCE: support control system to control shield support section movement in breakage face of mine contains central device of control (CDC) and set of control units (CU) each of those is located at corresponding section and functionally coupled with this section. At that CU of sections are connected with CDC and between each other with two bus bars and designed so as to facilitate a call of CU of any section from CDC or from CU of the neighbour section to control command input. Also CU of each section is programmed so as to transmit received control commands via the bus bar; the said commands, equipped with a code word assigned to the CU called at that moment, are transmitted to this particular CU for execution. Owing to the second analog bus bar (a parallel one) received signals not equipped with the code word assigned to the CU called at the moment, are transferred to CU of the neighbour section.

EFFECT: upgraded reliability of excavating machine and mechanised support due to safe and trouble free operation of their work with insignificant costs for maintenance.

2 cl, 3 dwg

FIELD: engines and pumps, mining operations.

SUBSTANCE: system composed of hydraulic units for underground mining operations is intended for, particularly, underground working supports, actuators and/or pickups, all of them being encased and interconnected or can be connected, via a data transfer system, to the control unit. Note that every actuator is designed to make every hydraulic unit function operate and/or every pickup is set up to read out the hydraulic conditions at the point of measuring whatever quantity of the walking support. Mind that every actuator (3) and/or sensitive element (7, 8) in its casing (4; 18, 19) are wired to readout unit (20; 30), while hydraulic unit (1) for every function (2) or every point of measurement is connected to data element (12; 13) connected in the circuit to allow a readout unit with a receiver and/or transmitted module (20; 30) to effect a contactless inductive data readout therefrom and to transmit the said data to control unit (6). Data element (12; 13) represents a transponder or a transmitter incorporating a receiver coil. The control unit (6) uses this data via the data transfer system to allow an automatic single-valued identification and reprogramming.

EFFECT: faultless connections.

8 cl, 3 dwg

FIELD: mining.

SUBSTANCE: system includes multiple control units (CU), each positioned at the respective section and functionally conjugated thereto. The CU of each section features multichannel transceiver, whereby a CU communicates to a portable decentralised control device for controlling signal reception and measurement and condition data transmission in the simultaneous transceiving mode. Section CUs are programmed so that controlling signals received by radio are not converted into lining section functions unless the controlling signal carries a code word assigned to the addressed CU. Section CUs are preferably interconnected by two electric buses for transmission of entered data to all section CUs and feature amplifier for restoration of signals received via electric bus.

EFFECT: improved operation reliability of winning machine and powered support due to sustaining safe and fail-proof operation at low cost.

3 cl, 3 dwg

FIELD: mining.

SUBSTANCE: lining sections are connected to an expansion tensioner (ET) conveyor consisting of power cylinders. The lining is equipped with a control system performing data collection and storage and programming continuous concordance of holding force distribution along the breakage face and/or amount of holding forces along the breakage face (total holding force) and/or advancing force distribution along the breakage face at given conveyor position. It allows determining total holding force in respect to the maximum set for it, by ET number, affecting total holding force by axial force adjustment for separate ETs, or affecting total holding force depending on the position of at least one end conveyor section.

EFFECT: minimisation of expansion tensioner number and pressure feeding them at reduced cost.

9 cl, 4 dwg

FIELD: mining.

SUBSTANCE: invention relates to the mining industry and is intended for monitoring movements of sections of the shield support in the working face of the mine. The system has a central control unit (CCU) and a number of peripheral control units (PCU), each of them being located beside the appropriate section and conjugated functionally with the same. PCU of sections are connected with CCU and interconnected by two electric buses so that each PCU can be activated from CCU or from an adjacent PCU for input of a control command. PCU of each section is programmed so as to transmit control commands received through the electric bus provided with a code word assigned to PCU to be activated. Besides PCU of each section has a switch, which enables to disconnect electric buses. By means of the second similar electric bus (the parallel bus) the input signal not provided with the code word assigned to PCU to be activated can be transmitted to PCU of the adjacent section.

EFFECT: safe, trouble-free and reliable operation of the winning machine and the powered support with insignificant expenses for maintenance.

3 cl, 3 dwg

FIELD: mining industry.

SUBSTANCE: method for extraction and underground use of coal includes cleaning extraction and dumping of coal, fixing and controlling ceiling and transporting coal along face to drift. On the drift, in moveable generator, coal is pulverized for intensive burning with use of jets in water boiler firebox, where high temperature of steam is achieved (about 1400 C), enough for decomposition of water on oxygen and hydrogen. These are separated, then oxygen is fed back to jets, and hydrogen is outputted along pipes and hoses in drifts and shaft. Variants of underground generator for realization of this method are provided. Also provided is method for extraction of disturbed coal beds by short faces. It includes extraction and dumping of coal on face conveyor, fixing of ceiling behind combine, moving conveyor line and support sections in direction of cleaning face displacement, control of ceiling with destruction and partial filling. Extraction of coal is performed in short curvilinear faces by long stripes along bed, in straight drive without forwarding drifts, with preservation and reuse of ventilation and conveyor drifts, equipped with mounting manipulator robots, with fixing behind combine by automatically operating support deflectors without unloading and displacing sections in area of coal extraction. Extraction and transporting of coal is performed by fast one-drum combine and curvilinear reloading conveyor, supplying coal to drift conveyor or immediately to underground gas or energy generator placed immediately on drift. Also proposed is face scraper conveyor for realization of said method, wherein pans are made with step along front face profile, greater, than along back one, while forming common line curved towards face with constant curvature. Also proposed is a method for controlling complex for unmanned coal extraction.

EFFECT: higher efficiency, effectiveness, broader functional capabilities.

8 cl, 5 dwg

Shield // 2219344
The invention relates to mining and can be used in mechanized mount Stopes in underground mining

FIELD: mining.

SUBSTANCE: system to control mining machine comprises a hydraulic drive of travel and a drilling rod with a power hydraulic control unit, a hydraulic drive of a loading element and hydraulic cylinders of a drilling rig with a power hydraulic control unit, an electrohydraulic unit of power hydraulic units control with a system of electric interlocks, sources of supply for hydraulic drive and control systems. At the same time power hydraulic units to control a hydraulic drive of travel, a drilling rod, a hydraulic drive of a loading element and hydraulic cylinders of a drilling rig are equipped with additional locking devices installed between sections of the hydraulic control units.

EFFECT: locking of the caterpillar drive and loading element drive during operation of drilling equipment to ensure safety of maintenance personnel.

1 dwg

FIELD: physics.

SUBSTANCE: system consists of an optical direction selector, a photodetector unit, as well as: a unit for controlling the direction selector, a signal matching unit, a microcontroller, a decoder, a matrix background polling module, bus-type conditioners, an interrupt signal generating unit, a switch, electric drives, a unit for monitoring and controlling electric drives, an optical transmitter control unit, an optical transmitter, a photodetector. All of these elements are interconnected.

EFFECT: determination of spatial coordinates of a mini-shield with high accuracy, which enables real-time communication with apparatus fitted on the mini-shield through a laser beam, endowing this system with noise-immunity and high speed of operation.

1 dwg

FIELD: mining.

SUBSTANCE: extraction device of coal in longwall face of underground mine working consists of the following: many sections of powered support, which are installed near each other throughout the length of longwall face between gates; plough machine; chute and conveyor located in it with possibility of movement, which are located throughout the length of longwall face between extraction machine and support sections; several deflecting devices and control device. Plough machine is provided with possibility of being moved along the line of the mining face and equipped with rock detection sensor which is provided with possibility of transmitting radio data of the detected rock to the control device of the support by means of the transmitter installed on the plough and the radio receivers installed along the longwall face. Group of adjacent support sections and sections of the chute corresponds to each deflecting device. Deflecting device is connected to control unit of one of the support sections of the appropriate group, and depending on the data of the detected rock, it provides the possibility of lifting the chute sections of the appropriate group, which is accompanied with lowering of the tools of the plough machine, and lowering of the chute sections, which is accompanied with lifting of plough machine tools. Control device includes the following: bottomhole control unit located at the end of longwall face for control of functions of support sections in relation to unloading, transportation and bracing of the support; control units of sections, each of which is put into spatial and functional compliance with the appropriate support section for performing and further transmitting the commands from bottomhole control unit; and the bus connecting mainly in series the bottomhole control unit to control units of support sections. At that, rock sensor when moving beside each support section is provided with possibility of generating the measurement signal characterising the detected rock only for several, mainly not more than two measurement points. Measurement signals received at neighbouring measurement points are subject to analysis with a view to predominance of rock or coal. Depending on analysis results, there generated is deviation signal supplied to the common deflecting device common for all measurement points, and namely to the deflection of the chute sections, which causes the lifting of plough machine tools if analysis results show the predominance of rock at the analysed measurement points, and to deflection of the chute sections, which causes the lowering of the plough machine tools if the analysis results show coal predominance at the analysed measurement points.

EFFECT: possible quick correction of the plough machine position during the coal extraction, which causes the lifting and lowering of the plough.

9 cl, 2 dwg

FIELD: mining.

SUBSTANCE: invention relates to the field of mining and may be used in designs of mining machines and other fields of machine building. Hydraulic system of mining machine control is additionally equipped with hydraulic cylinders of telescope tightening, in working manifolds of which there is a hydraulic valve installed with logical function "OR", as well as controlled check valve with control cavity, besides inlet manifolds of hydraulic valve with logical function "OR", which is installed in working manifolds of hydraulic cylinders for telescope tightening, are connected to outlet channels of hydraulic valves with logical function "OR", which are installed in outlet channels of hydraulic distributors for control of hydraulic cylinders of actuator lift and rotation, and control cavity of controlled check valve is connected to outlet channel of hydraulic valve with logical function "OR", which is installed in outlet channels of hydraulic distributor for control of hydraulic cylinder of telescope extension.

EFFECT: invention increases rigidity and reliability of support structures of mining machine actuator, improves durability of machine as a whole.

1 cl, 1 dwg

FIELD: mining.

SUBSTANCE: device for orientation of tunnelling system during construction of curved tunnels includes the units located in line of sight and at the specified distance from each other, the end ones of which are rigidly fixed, one - in starting tube, and the other one - on tunnelling shield, intermediate units are installed inside the erected part of the tunnel, each unit is equipped with a photo sensor, light emitting element and roll sensor, also, the device is provided with sensor of amount of advance and data transfer channels between the device assemblies and computing unit with a display; at that, each unit is equipped with a plate with sector symmetric light-tight slots, plate is located on motor shaft the axis of which coincides with the direction of tunnelling operation, on both sides of the plate in horizontal and vertical planes passing through motor axis there installed are light-emitting elements directed to the plate side; at that, each unit contains differently directed photo sensors oriented parallel to motor axis.

EFFECT: improving the orientation accuracy of tunnelling system and operating characteristics of the device, and increasing standardisation of the device components.

3 dwg

FIELD: mining.

SUBSTANCE: group of inventions is related to system and methods for control of getting machine along bottomhole in underground mine tunnel, and also to mining face for method realisation. Method includes measurement of gas concentration and depending on measurement results, generation of warning signal. At the same time volume of production achieved by getting machine is additionally established. In case of insufficient correlation between volume of production and gas concentration, a warning signal is generated.

EFFECT: invention provides for possibility to minimise danger of methane gas explosion in mining face, to establish fact of gas sensor failure and/or manipulation with it.

26 cl, 3 dwg

FIELD: mining.

SUBSTANCE: system consists of optical master of direction- laser, of diaphragm, of photo-receiving device, of interface module, of sensors of position of each degree of actuator mobility, of tilt sensor, of blocks of control over electro-hydro-valves and of computer device. The photo-receiving device consists of semi-transparent mirror assembled at angle of 45 to lengthwise axis of the case of the device, of two screens - the tail and knife ones with zero-marks, and of two video-modules. The tail screen is arranged above reflecting surface of the semi-transparent mirror so, that it is parallel to lengthwise axis of the device, while the knife screen is located at some distance beyond non-reflecting surface and perpendicular to lengthwise axis. Each video-module is installed behind the corresponding screen at the focal distance of the objective.

EFFECT: upgraded reliability and efficiency of control over actuator.

6 dwg

FIELD: mining.

SUBSTANCE: device for control over arrow of operating member of mining machine consists of hydro-cylinders of vertical lifting an horizontal turn and of arrow telescope, of half-throttle, included into line feeding working fluid into piston cavities of lifting hydro-cylinders, of double-sided hydro-locks included into feeding lines of lifting hydro-cylinders and telescope, of main distributors of hydro-cylinders control for lifting, turn and telescope, which are successively arranged to provide free overflow of working fluid into tank in neutral position, of main electro-hydro-distributors for control over main distributors and over additional distributor automatically switched on. There is also a main and additional pumps, a pressurising collector, safety valves, test pressure gages, a pressure regulator, a tank for hydro-system working fluid, and a control panel with buttons for six commands. Further the device contains a control station with a circuit of three memory elements and the element of logical function or operation, additional distributors with back valves on their outputs and correspondingly with throttles on control lines, pointed sensors of feedback, installed correspondingly on the hydro-cylinders and connected to memory elements.

EFFECT: power stabilisation of operating member of mining machine, increased efficiency of working member drive operation, increased energy saving at mine working and grade of extracted coal.

3 cl, 4 dwg

FIELD: mining.

SUBSTANCE: invention relates to mining, in particular, to navigation system of combined cutter-loader intended for operations in open-pit bench. This mining equipment includes a combined cutter-loader, a conveyor assembly, and a steering assembly, which joins said combined cutter-loader and conveyor assembly. In addition, this equipment includes a course sensor and a steering device, which is sensitive to signals from said course sensor. The first drive is located in combined cutter-loader, in conveyor assembly, or in steering assembly. The first drive is placed on one side of combined cutter-loader centreline. In addition, the second drive is located either in combined cutter-loader, or in conveyor assembly, or in steering assembly. The second drive is placed on another side of combined cutter-loader centreline. The first and the second drives are used to adjust angle of joint between combined cutter- loader and conveyor assembly on either side of parallel line in order to keep pre-defined direction of combined cutter-loader advancing.

EFFECT: precise driving of combined cutter-loader in order to increase coal cutting from mining zone.

22 cl, 13 dwg

FIELD: mining, particularly remote control specially adapted for machines for slitting or completely freeing the mineral.

SUBSTANCE: device comprises the first, the second and the third asynchronous motors. The first and the second electric drives are connected to drive sprocket of closed pull chain provided with plough carriages, which may move along guiding means. Device also has hydraulic cylinders to move guiding means to face, mechanical gear, the first and the second safety hydraulic valves, the first and the second hydraulic pumps, the first and the second frequency converters, the first and the second frequency regulators, load sensors, load balancing unit, load regulator, load assignment unit, control unit, initial setting signaling unit, hydraulic distribution means, which control hydraulic cylinders to move guiding means to face, hydraulic units, electrohydraulic unit, channel switching unit, flow meter, excavated seam thickness setting unit, breakage face length setting unit, multiplication unit, divider, optimizing peak-holding controller, control signal generation unit, asynchronous single-phase motor and screw gear made as a nut and screw. The first and the second hydraulic pumps include volume regulation means.

EFFECT: reduced specific energy consumption along with increased front plant output.

1 dwg

FIELD: mining industry.

SUBSTANCE: device has two asynchronous electric engines, connected via reducers to drive sprockets of continuous traction chain, provided with plane carriages with their possible displacement along the guide, and hydraulic cylinders for displacing guide on pit-face. To windings of stators of first and second electric engines connected respectively are outputs of first and second frequency converters, inputs of which are connected to power grid and control inputs of which are connected respectively to outputs of first and second frequency adjusters. To frequency adjusters also connected are inputs of load detectors, to outputs of which load balancing block is connected, outputs of which are connected to inputs of first frequency adjuster. To inputs of both frequency adjusters output of load adjuster is connected, inputs of which are connected to load-setting block and load sensor for second engine. To output of second frequency converter connected are input of control block, other input of which is connected to signal block of base plant, and stator winding of third asynchronous engine, which via mechanical link is connected to first and second hydraulic pumps, having constant working volumes. Output of first hydraulic pump is connected to force hydro-main and input of second preventing hydraulic valve and to first inputs of two-position hydraulic distributors with electromagnetic control, to electromagnets of which outputs of control block are connected. Second inputs of two-positional hydraulic distributors with electromagnetic control are connected to control chambers of hydro-controlled two-positional hydro-distributors, which are part of hydro-blocks. Outputs of hydro-controlled two-positional distributors are connected to opposite hollows of volumetric dosing device of each hydro-block, and their inputs are connected respectively to outputs of hydro-distributors for controlling hydro-cylinder for moving the guide on pit-face, inputs of each of which are connected to force and drain hydro-mains, and outputs are connected to piston and rod hollows of appropriate hydro-cylinder.

EFFECT: higher efficiency.

1 dwg

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