Full-cut heading machine   

The invention relates to a full-cut heading machine including a drill head for hard rock, which is rotationally mounted about an axis of rotation extending in the driving direction, as well as downstream extraction tools for producing a floor widened in the floor region.

Heading machines are known in various configurations. From DE-AS 1260412, a configuration has become known, in which additional tools are arranged at a distance from the longitudinal axis of the machine in the lower region of the heading machine behind the drill head, viewed in the driving direction, which are able to work off the material left behind by the drill head. In that known configuration, the axes of the additional drilling tools are oriented parallelly to the longitudinal axis of the machine, and a bucket chain conveyor is provided behind the two extraction tools to receive the material. In the event of hard rock, suitably adapted extraction tools are, however, required, thus rendering the beginning of extraction relatively difficult in the direction to the mine face on account of the direction of rotation of the additional tools, whereby the widening of the floor is accordingly limited.

In DE 3121244 A1, a number of drill heads equipped with roller bits are provided behind the supporting device of a full-cut drill head, those additional drill heads being again rotationally mounted about rotational axes extending parallelly to the axis of the main drill head. In that configuration too, a substantial widening of the floor will only be feasible if the additional rotating cutter heads are accordingly pivotally mounted and become outwardly displaceable relative to the central axis of rotation, thus requiring relatively expensive driving means.

Additional laterally displaceable and pivotable extraction tools are described in DE 3421704 A1. In that previously known configuration, the downstream extraction tools are adjusted relative to the lateral wall and pivoted in the direction of the lateral widening of the floor. To this end, a supporting structure is provided, which defines a free space in the lower region, as in the case of a portal, wherein the disclosed device can be attached directly behind a drill head such that a walling can be set in the gallery or in the drift, without requiring interim protection measures. The supporting structure, however, requires additional space within the gallery and may impede walling.

The invention now aims to provide a full-cut heading machine which, in particular, is especially suitable for mining in hard rock, and by which a circular gallery profile can initially be cut, whereupon an almost plane floor is to be obtained without reducing the overall driving performance. At the same time, the configuration is to be designed sufficiently compact to hinder as little as possible the driving of the track, and is to be designed to ensure a sufficiently high driving performance also by the downstream extraction tools in the event of material having a high cube compressive strength, and/or of hard rock.

To solve this object, the configuration according to the invention essentially consists in that the downstream extraction tools are arranged on the shells, and optionally end faces, of rollers rotationally mounted transversely to the axis of rotation of the drill head. Due to the fact that the downstream drill heads or extraction tools are arranged on the shells or end faces of rollers, disc tools can again be used, as with the central drill head, so as to enable the achievement of cutting performances adapted to the material to be extracted. In a particularly advantageous manner, the configuration is devised such that the extraction tools are designed as roller bits.

In order to ensure rapid walling and a high driving performance even with hard rock while, at the same time, achieving a largely plane floor, the configuration is advantageously devised such that, outside the vertical longitudinal central plane, two rollers are rotationally mounted, whose axial length is between 50 and 75%, preferably 60 to 70%, of the radius of the drill head, wherein the downstream roller bits are preferably mounted on the shells of the rollers with the axes of rotation extending substantially parallelly to the axes of rotation of the rollers. Such dimensioning of the rollers, and such an arrangement of the axis of rotation of the roller bits, allow the respective dimensions and distances to be selected with a view to achieving an accordingly optimized overall driving performance adapted to the cube compressive strength of the respective material to be excavated. In this respect, the configuration is advantageously devised such that the axial distances of the roller bits distributedly arranged on the shell are 75 to 100% of the radial distances of the roller bits of the drill bit. In this manner, the same cutting parameters as with the discs of the rotational main drill head can be maintained.

In a particularly advantageous manner, the material cut by the discs of the rollers can be taken up by clearing tools which become active themselves also in association with the rotationally mounted drill head. In order to enable such haulage, the configuration is advantageously devised such that the rollers are drivable for rotation from the floor upwardly to the mine face, wherein the drill head, and/or a carrier coupled with the drill head, preferably carry clearing tools, in particular chutes and/or shovels, for taking up excavated material, which are movable onto a haulage device via a discharge site. The clearing tools of the drill head may be comprised of rigid chutes fixed within the drill head. Connected with the drill head may be a rotating carrier with folding shovels each throwing the received material onto the conveyor belt on a delivery or discharge site to a haulage device.

In order to prevent the floor from being dug off too deeply by the roller disc tools, and the entire heading machine from tilting as a whole relative to the mine face, a special type of floor support will be of particular advantage, to which end the configuration is advantageously devised such that a slide-like floor support extending from an end facing the mine beyond the projection of the axes of rotation of the rollers on the floor is arranged in the vertical longitudinal central plane of the heading machine. Such a slide-shaped or skid-shaped support in terms of contour may correspond with the outline shape of the rotationally mounted drill head and, therefore, rest stably on the floor via a relatively large surface area, the floor widening becoming effective outside the floor support slightly higher than the tangent to such a skid-shaped or slide-shaped floor support. The support extends beyond the axis of rotation of the roller in order to be able to also safely absorb reaction forces.

In the following, the invention will be explained in more detail by way of an exemplary embodiment schematically illustrated in the drawing. Therein,

FIG. 1 is a front view of the full-cut heading machine according to the invention;

FIG. 2 is a view in the same direction on a section along line II-II of FIG. 3; and

FIG. 3 depicts an axial section through the forward region of the heading machine according to the invention.

FIG. 1 depicts a drill head 1 for hard rock, which carries rotationally mounted extraction tools or disc tools 2. The discs are rotationally mounted about substantially radial axes. In the illustration according to FIG. 1, portions of the laterally cantilevering rollers 3 and 4 are respectively visible in the lower region, each again carrying extraction tools or disc tools 5. The disc tools 5 provided on the rollers 3, 4 serve to cut or excavate the floor widening. From the illustration according to FIG. 2, the rollers 3 and 4 as well as the disc tools 5 arranged on these rollers are again visible. The distance a of adjacent disc tools on the shells of the rollers 3 and 4, respectively, in this case is chosen as a function of the radial distances of the discs 2 of the drill head 1 in order to optimize the cutting performance. The axis of rotation of the drill head is denoted by 6 in FIG. 2, on which also the skid-shaped floor support 7 resting on the floor 8 is apparent. The machine is equipped with lateral supports 9 as well as a roof support 10, which can be pressed against the already cut road or tunnel profile. The pressing cylinders for the supports 9 are, for instance, denoted by 11.

From the illustration according to FIG. 3, discs 2 are again apparent, which are rotationally mounted on the drill head 1. The drill head 1, moreover, carries shovel-like chutes 12, via which material is upwardly conveyed at a rotation of the drill head about the axis 6 and which enable the throwing off of cut material on an upwardly located delivery site to a haulage device 13. The axes of rotation of the rollers 3 and 4 are denoted by 14, the envelope cut by the rotating bits being indicated at 15.

A carrier 16 connected with the drill head 1 carries folding shovels 17, via which the material cut and taken up by the rollers rotating in the sense of arrow 18 is again conveyed towards a delivery point to the haulage means 13.

The floor support in the form of a skid 7 extends below the axis of rotation 14 of the roller 3 from a front end facing the mine face 19 to a rear end 20 located behind the projection of the axis 14, thus effectively counteracting tilting of the heading machine.