GB2138467A - Front-end-coal-winning unit - Google Patents

Abstract

The front-end coal-winning unit comprises a cutting-and-conveying member (1) of the conveyor type, having a base (3), carriages (5) supporting a working member (6) for breaking the coal, movable relatively to the base (3), and a base beam (9) made up of a plurality of successive sections. Each section includes a frame (18) having mounted thereon a bracket (19) pivotably supporting one end of an arm (22) of which the other end is connected with the base (3), the arm being pivotable by a hydraulic jack (25). The piston-rod (26) of the hydraulic jack (25) is pivotably connected with the arm (22), while its housing (29) is connected with the frame (18) of the respective section. <IMAGE>

Description

SPECIFICATION Front-end coal-winning unit The invention relates to coal-excavating machinery, and more particularly it relates to a front-end coalwinning unit.

The invention can be utilizedforwinning coal from gently-sloping coal beds, essentiallyfrom 0.6to 0.9 m thick.

There is known a front-end coal winning unit predominantly intended for steeply sloping coal bed longwalls. Itcomprisesafront-endannularcutting- and-conveying member, a power roofsupport, hydraulic and electric equipment. The cutting-and-conveying member includes planing carriages with either oneorseveral planing blades, and scrapers for conveying coal, supported on an endless drag chain.

The framework of the cutting-and-conveying member serves as the base ofthe unit, its individual elements being interconnected pivotallywhich, on the one hand, provides for adequate rigidity ofthe unit in the direction of itsfeed againstthe working-face, and, on the other hand, allowsforflexibility ofthe unit along a stope, so that the unit can match itself to the bed hypsometry.

In operation, the flight or framework of the unit is permanently urged orfed againsttheworking4ace by the hydraulic cylinders orjacks of the unit, the blades of the carriages cutting off the coal bed chips as thick as 80 mm, while simultaneouslythe scrapers ofthe lower run ofthe cutting-and-conveying member carry the cut-off coal toward the adjoining drift.

The drag chain ofthe cutting-and-conveying member is actuated bytwo drives arranged at the ends of the unit. The carriages of the cutting-and-conveying member move along tubular guideways pivotally connected to one another and secured to the vertical wall of each linear section ofthe flight framework. The guideways are adjustable in a vertical plane to control the thickness ofthe layer being excavated.

This front-end coal winning unit is not adapted for operation with gently-sloping beds or seams.

There is known anotherfront-end coal-winning unit for excavating coal when mining steep seams or beds.

It comprises a power roof support and a front-end annular cutting-and-conveying member including a base, a drive, a stationary base beam, carriages with working members, mounted on a chain closed in the plane of the seam or bed, mechanisms for moving the cutting-and-conveying member and a hydraulic system.

The cutting-and-conveying member is connected to the unitsoftheshield-type power roofsupport through motion mechanisms including a telescopic pendulum arm and two feed hydraulic cylinders or jacks, responsible, respectively, forthe feed in the dip and across the thickness ofthe seam or bed.

Excavation of coal by the member is performed simultaneously overthe entire length ofthe workingface, the member cutting-in adjacent to the roof ofthe seam and then working it across the entirethickness, while moving toward the floor. With coal having been excavated to the present depth (the cutting extent), the unit is fed against the working-face.

The roller-supported carriages with the working memberfor breaking the coal are mounted movably relativelyto the base beam, while the base is movable relatively to the working-face by the hydraulicjacks.

The last-described unit, same as the previously described one, is not for operation with gently-sloping coal seams or beds, particularly,thin ones-asthin as 0.6to 0.9 m, because both abovementioned units have their parts and assemblies of considerable height and are intended for use with coal seams at least 1.2 m thick.

It is an object of the present invention to create a front-end coal-winning unit which should provide for stepping-up the efficiency of coal excavation work with gently-sloping seams 0.6to 0.9 m thick.

This object is attained in a front-end coal-winning unit comprising a cutting-and-conveying member of the conveyor type, having a base movable relativelyto the working-face by hydraulicjacks, a stationary base beam made of a plurality of successive interconnected sections and connected to the base, and at least two carriages supporting each a working memberfor breaking the coal, movably mounted relatively to the base, in which coal-winning unit, in accordance with the invention, each section ofthe base beam includes aframe having mounted thereon a bracket, the motion ofthe base ofthe cutting-and-conveying member relatively to theworking-face being provided for bythe bracket of each section having pivotally mounted thereon an arm of which the opposite end is connected to the base, the arm being pivotable by a hydraulicjack having its piston-rod pivotally connected to the arm and its housing connected with the frame ofthe respective section.

Preferably, the frame of each section has mounted on the working-face side thereof a guide, so that the guides of the successive sections define a coalconveying path.

The present invention will bye further described in connection with an embodimentthereof, with reference being made to the accompanying drawings, wherein: Fig. lisa schematic general view of a front-end coal-winning unit embodying the invention; Fig, 2 is a sectional viewtaken on line ll-ll of Fig. 1; Fig. 3 is a sectional viewtaken on line Ill-Ill of Fig. 2.

In the drawings, the front-end coal-winning unit intended for excavating coal from seams 0.6 to 0.9 m thick, with the incline from O"to 350 comprises a cutting-and-conveying member 1 (Fig. 1 ) of the conveyortype and a power roof support 2.

The cutting-and-conveying member 1, in its turn, includes a base 3 and hydraulic cylinders or jacks 4for moving the base 3, the latter being adapted to extend the entire length of the longwall. The carriages 5 supporting a working member 6for breaking the coal and the conveying carriages 7 are dragged by a chain 8 running along a closed pathin vertical plane, relatively to the stationary base beam 9 which is made up of a plurality of successive sections.

Adapted to be accommodated in the adjoining haulage and vent drifts are the two drive heads 10 whose frameworks 11 have the base 3 secured thereto, the base 3 in the presently described embodiment, same as the base beam 9, being made up of a plurality of successive sections of which the number equalsthe numberofthesectionsofthe base beam 9.

The successice sections ofthe base 3 are connected to one another by tubular members 12 (Fig. 2). The successive sections of the base beam 9 are interconnected in a similar way, buttheirjoints are not shown in the appended drawings for clarity sake.

The drag-chain 8 is tensioned with aid of hydraulic cylinders orjacks 13 (Fig. 1) mounted on the respective drive heads 10 and connected with their stationary frameworks 11 and movableframes 14.Thestationary frameworks 11 are secured on beams 15 accommodated in the respective drifts.

The drive heads 10 are provided with hydraulicjacks 16for moving the heads 10 along the respective drifts, simultaneously with the motion ofthe base 3 jointly with the base beam 9 relatively to the longwal I. Beams 17 connect the hydraulic jacks 16 with the drive heads 10 and the beams 15.

Each section ofthe basebeam9includesaframe 18 (Fig. 2) supporting a bracket 19 at the side thereof, opposite to the working-face, and a guide or chute 20 at the working-face side. The bracket 19 carries a pivot 30 supporting one end of an arm 22, its other or opposite end being connected through a pivot 23 to the respective section of the base 3.

Extending through an opening 24 in the arm 22 is a hydraulic cylinder or jack 25 of which the piston rod 26 is connected by a pivot 27 to a lug 28 on the arm 22, internally of this lug 28, while the housing 29 is connected buy a pivot 30 to the frame 18.

The position ofthe base 3 relative to the thickness of the coal seam is present with aids of screws 31 and nuts 32 adjustable along the respective screws 31, each screw31 extending through openings33 in the respective arm 22, thus interacting with this arm 22 and limiting the angle of its pivoting, thus limiting the height of the raising ofthe entire cutting-and-con veying member 1 (Fig. 1). Each screw 31 (Fig. 2) is mounted by a pivot 34 on the bracket 19.

The base3 is adjustable relatively to the floor of the seam with aid of screws 35 extending through lugs 36 on the respective frame 18 and limiting the degree of the lowering ofthe arms 22, and, consequently, the lowering ofthe cutting-and-conveying member 1 (Fig.

1).

Also illustrated in Fig. 2 is the connection ofthe ca rriage 5 with the chai n 8 with aid of bolts 37 and nuts 38.

Each section ofthe base 3 carries an abutment 39 limiting the thickness of coal chips cut off by the working member 6.

The guides or chutes 20 (Fig. 3) ofthe adjacent sections ofthe base beam 9 closely adjoin one another to define a coal-conveying path, their shape and material being selected to reduce the angle offriction while conveying the coal. They are interconnected by bushes40and pins 41.

The herein disclosed front-end coal-winning unit is operated, as follows.

With the electric motors 42 energized, drive heads start moving the chain 8 along its closed vertical path.

The carriages Sand 7 supported bythe chain 8 move along the base 3, the latter being fed relatively to the working-face jointlywith the base beam 9 by their hydraulicjacks, while the drive heads 10 are advanced bythe hydraulicjacks relativelytothe entire longwall, with the working members 6 on the carriages 5 breaking the coal seam. The broken-off coal falls onto the inclined guides 20, and the carriages Sand 7 convey ittoward the haulage drift.

To adaptthe unitto the seam thickness, the vertical position or height ofthe cutting-and-conveying member 1 is controlled by operating the hydraulic jacks 25 which, when projected or extended, make the arms 22 pivot abouttheir stationary pivots 21, moving their respective sections of the base 3 so that the working members 6 ofthe carriages 5 cut the coal across the entirethickness of the coal seam, from its floorto the roof, as it is illustrated in hair lines in Fig. 2.

With the piston rods ofthe hydraulicjacks 25 retracted or pulled-in, the base 3 lowers to the ground, and the carriages 5 and7 conveythe coal alongthe guides 10 and 3 of the longwall.

The entire unit is controlled throughoutthe process of excavating coal within the advancing step of the power roofsupport 2 from the adjoining drift through hydraulic controls, so that no operators are required at the longwall in the coal-winning process.

The herein disclosed front-end coal-winning unitfor operation with seams 0.6 to 0.9 m thick has great power ratings and the correspondingly greatthroughout, owing to the possibility of accommodating the drives ofthe unit in the adjacent drifts, which would not be obtained with either cutter-loader or planing excavation techniques when the drives are to be accommodated atthe longwall, on account of the height ofthe working space available being inadequate. The personnel safety is enhanced, too, owing to the unit excavating coal without attendance atthe longwall, as the operators remain there butfor brief periods of starting and adjustment operations, while the actual operational control is performed from the adjoining drift.

The power input into coal-breaking is reduced, owing to the cutting teeth being spaced longitudinally oftheworking-face and coal being broken-off in the area where it is pressed-out bythe rock pressure over the entire length ofthe longwall, so that the power input into coal-cutting attheworking-face is reduced by 10 to 12 percent. Besides, there is no need for preparing in advance the holes which claim from 20 two 40 percent of the total laboutconsumed by excavating coal from longwalls bythe cutter-loadertechnique.

With no drives in the longwall area, the unit is betterfit to fol low closely the curvatu re of thin seams.

The structure ofthe power roof support can be simplified, too, as the front row of the props is arranged significantly closerto the working-face line.

The unit is simplerto operate, with its controls having been removed from the longwall into the more spacious drift.

Claims (3)

1. Afront-end coal-winning unit comprising a cutting-and-conveying member ofthe conveyor type, having a base movable relatively to a working-face by hydraulicjacks, a stationary base beam made up of a plurality of sections connected to one another, the base beam being connected to the base, and at least two carriages carrying each a working member for breaking the coal, mounted for motion relatively to the base, said sections of the base beam including each a frame having a bracket mounted thereon, the motion ofthe base of the cutting-and-conveying member relativelyto the working-face being provided for by the bracket of each section having pivotably mounted thereon one end of an arm of which the other end is connected with the base, the arm being pivotable by a hydraulic jack of which the piston-rod is pivotably connected with the arm and the housing is connected with the frame ofthe respective section.

2. Afront-end unit as claimed in Claim 1, wherein theframe of each section carries on the working-face side thereof a guide so arranged that the guides ofthe successive sections define a coal-conveying path.

3. Afront-end coal-winning unit, as claimed in any one ofthe preceding Claims, substantially as hereintofore described with reference to the appended drawings.