Mining or in situ disintegration of hard material – Hard material disintegrating machines – Sidewall-working
Reexamination Certificate
1999-01-15
2001-01-30
Will, Thomas B. (Department: 3673)
Mining or in situ disintegration of hard material
Hard material disintegrating machines
Sidewall-working
Reexamination Certificate
active
06179386
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a driving and guide arrangement for a mining machine which travels along a scraper chain conveyor, in particular for a drum cutter machine, with a guide rail arranged on the trough sections of the scraper chain conveyor above the level of the trough sections, and bounding a chain channel for a chain allowing the machine to haul itself along the mining face, with the horizontal links of the chain resting on support elements arranged within the chain channel, the latter being provided with openings underneath the chain to allow fines to fall through.
BACKGROUND OF THE INVENTION
An arrangement of this kind is known from DE-OS 4423925. In this arrangement the support elements for the horizontal links of a pin drive chain consist of support ledges extending over the length of the conveyor trough sections, with the vertical links of the pin drive chain engaging in, and practically entirely occupying, the slot-form space between the stowing-side and face-side ledges. The discharge openings for the fines in this known arrangement are open towards the gob or stowing side of the conveyor.
It has been found that the discharge of fines from the chain channel does not always function satisfactorily in the known construction. In most cases this is because the continuous support ledges and the vertical chain-links engaging in the space between them leave relatively little clearance for eg. coal dust etc. to fall through on its way to the fines discharge openings. Consequently, caking of fines on the pin drive chain in the chain channel is a frequent occurrence. As a result, a correct engagement of the chain-wheel in the pin drive chain is no longer assured, and there may even be damage to chain-wheel and guide.
It is the object of the invention to provide a particularly simple and inexpensive arrangement of the above-mentioned kind in which accumulations of fines in the chain channel accommodating the pin drive chain can be more reliably avoided, and an easier discharge of fines from the openings underneath the drive chain is obtained.
SUMMARY OF THE INVENTION
To achieve this object the support elements are formed as rest elements spaced apart from one other and engaging the horizontal chain-links from below, the individual rest elements having a limited dimension in the direction of travel of the mining machine, and the openings for discharge of fines are provided both on the stowing side of the chain channel and on its working front-facing side.
Utilizing only spaced elements that are themselves short or narrow in the travel direction of the mining machine as supports for the chain-links, fines which get into the chain channel have sufficient clearance between any two adjacent support elements on either side of the vertical chain-links to be able to fall to the bottom of the chain channel, whence they can re-emerge on the working side as well as on the gob side. This arrangement largely eliminates the risk of accumulations of fines and caking or clogging in the chain channel.
In a preferred form of the invention, the chain channel is made as a welded construction bounded on its working, front-facing side by the guide rail and on its rear, gob side
by a rear wall, and welded connecting plates interconnect the rear wall and the guide rail. This configuration as a welded construction yields considerable cost and weight benefits. A particularly convenient arrangement is obtained by forming the connecting plates as support elements for the horizontal chain-links and providing them with recesses for the vertical chain-links. The connecting plates then perform a dual role, as they not only provide the bridge between the guide rail and rear wall components which bound the chain channel, but simultaneously serve as support elements for the chain-links. The lower region of the rear wall may be bent towards the guide rail, so as to bound the chain channel at the bottom as well as at the rear.
The guide rail preferably consists essentially of a rolled or extruded section, which can have smaller dimensions and weights in comparison with the cast section that is still often used, and to which the connecting plates can be welded without any problem. The smaller dimensions and weights and the good weldability of the components can result in quite considerable cost advantages in relation to known designs. The fines discharge openings can consist basically of cutouts in the rear wall and/or guide rail, located between the connecting plates, preferably of trapezium form with the wider parallel side at the base. A particularly advantageous configuration is obtained by locating the guide rail a certain distance above the bottom boundary of the chain channel on the front side of the chain channel, thus forming between the guide rail and the bottom boundary of the chain channel a front fines discharge opening which can then conveniently extend over the whole length of the conveyor trough sections and/or of the chain channel itself. In this case, a guide shoe may be arranged on the mining machine so as to project through the front discharge opening to the conveyor trough and underneath the guide rail. This guide shoe not only serves to guide the drum cutter machine or its equivalent correctly on the guide arrangement, but additionally may be formed as a kind of scraper which rakes out any fines which have not already emerged from the chain channel through the discharge opening.
The upper part of the guide rail may have a rail profile for a slide block and/or for one or more running wheels of the mining machine. In this case it is particularly advantageous for the rail profile to be approximately semicircular, engaging in a matching groove in the periphery of a running wheel. With this configuration, the mining machine is guided in a positive manner transversely with respect to its direction of travel. It is convenient to provide the guide rail with a projection in the region of the rail profile or of the lower edge of the rail, which overhangs a derailment preventer arranged on the mining machine. This will ensure that the running wheel or slide block of the mining machine cannot be derailed.
The guide rail is conveniently provided, in a manner known in itself, with ledge-like projections which protrude into the chain channel and overhang the face-side shanks of the horizontal chain-links inside the chain channel. These projections prevent the drive chain from being lifted out of the chain channel. In a similar fashion, retaining bars can also be releasably attached on the stowing side of the chain channel after the chain has been inserted, so that these bars overhang the stowing-side shanks of the horizontal chain-links. After the retaining bars have been removed, the drive chain can be laid in the chain channel from above, or removed from above when replacement is necessary.
The bottom boundary of the chain channel may be given a ridged, somewhat roof-like form, in which the ridge may be located approximately in the longitudinal centre plane of the chain channel and chute surfaces for the fines falling away on either side of the ridge to the fines discharge openings. The provision of such sloping chute surfaces assists the unhindered discharge of the fines which have entered the chain channel.
Further features and advantages of the invention will be apparent from the description which follows and from the drawings, in which preferred embodiments of the invention are described in detail with reference to some examples.
REFERENCES:
patent: 4099786 (1978-07-01), Nakajima et al.
patent: 4235475 (1980-11-01), Monks
patent: 4346938 (1982-08-01), Braun
patent: 5601341 (1997-02-01), Merten et al.
patent: 2445327 (1975-04-01), None
patent: 44 23 925 (1996-11-01), None
Merten Gerhard
Meya Hans
DBT Deutsche Bergbau--Technik GmbH
Kreck John
Vickers Daniels & Young
Will Thomas B.
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