HEADING MACHINE

Abstract

In a heading machine (1) including a travelling mechanism (2) and a cutting boom (3) or frame, the cutting boom (3) or frame carries at least two rotating cutting heads (5) whose axes of rotation (6) extend in the heading direction or enclose acute angles with the heading direction and which, together, define a cutting profile having a profile width (a), as well as two cutting rollers (8,10) arranged substantially parallel and behind the cutting heads (5) and capable of being positioned on the floor (9) and on the roof (7), respectively. Both cutting rollers (8,10) comprise end portions (25) which are extendible to the width (a) of the profile for the formation of a substantially rectangular cutting profile.

Description

The present invention relates to a heading machine including a travelling mechanism and a cutting boom or frame, wherein the cutting boom or frame carries at least two rotating cutting heads whose axes of rotation extend in the heading direction or enclose acute angles with the heading direction and which, together, define a cutting profile having a profile width, as well as two cutting rollers arranged substantially parallel and behind the cutting heads and capable of being positioned on the floor and on the roof, respectively.

Heading machines with cutting rotors whose axes of rotation extend in the heading direction or enclose acute angles with the heading direction are usually denoted as “Marietta drills”, wherein the cutting unit comprises two or several rotating cutting heads. The two cutting heads define a cutting profile with a maximum profile width, wherein the cutting tools are usually arranged on the cutting heads in a manner that cutting tools of one of the cutting heads engage between cutting tools of the other one of the cutting heads during rotation such that the circular areas of the respective cutting profiles will overlap one another. The common cutting profile of the two or more cutting heads arranged adjacently and, preferably, on the same level will, therefore, as a rule, correspond to the respective number of partially overlapping circular areas, with so-called profile gussets remaining between the individual circular areas in the region of the floor and the roof. The edge of the profile is limited by two half-circles.

In order to straighten the profile corners left by the rotating cutting bodies, a trim chain is known from U.S. Pat. No. 3,343,882, by which the floor profile and the roof profile can be partially straightened.

An alternative embodiment of a trimming device is known from U.S. Pat. No. 3,407,006, in which vertically readjustable cutting rollers are provided, which are fixed to the frame of the cutting device in order to obtain straightened floor and roof profiles.

From U.S. Pat. No. 5,921,632, a trimming device for a Marietta drill has become known, in which a telescopable cutting roller is arranged on the cutting frame of the heading machine in a vertically adjustable manner for trimming the floor. On the roof, the cut gusset is trimmed by a cutting roller immovably fixed to the cutting frame. The trimming device known from U.S. Pat. No. 5,921,632 is connected with a central drive via gear shafts.

It is true that the use of heading machines known from the prior art enables the cutting-away of the cutting profile gussets between the circular segments on the roof and the floor by the aid of trimming devices. Yet, the tunnel profile will keep its round shape in the roof corners. This is, in particular, highly disadvantageous in potassium mining, where an enlarged tunnel profile is achieved in that several parallelly extending profiles immediately adjoining each other laterally are driven one after the other to jointly produce the desired, enlarged tunnel profile. With such a mode of procedure, the cut gussets remaining when using heading machines known from the prior art, as well as the profile curves on the edges of the profile, are particularly annoying, since they will either have to be removed by separate devices or constitute a considerable risk, since the rock can easily break away from such remaining profile regions.

The present invention, therefore, aims to provide a heading machine which enables the driving or forming of a substantially rectangular tunnel profile, while avoiding the above-described drawbacks.

To solve this object, the heading machine according to the invention of the initially defined kind is essentially characterized in that both cutting rollers comprise end portions which are extendible to the width of the profile for the formation of a substantially rectangular cutting profile. Due to the fact that both the upper cutting roll, i.e. the one to be positioned on the roof, and the lower cutting roll, i.e. the one to be positioned on the floor, comprise extendible end portions, it has become feasible to enlarge the effective cutting width of the cutting rollers to the profile width defined by the other cutting tools, namely the rotating cutting heads. This enables the cut gussets remaining between the individual circular areas of the cutting heads to be substantially completely cut away such that a substantially rectangular cutting profile will be obtained. It is, furthermore, feasible to cut away the quarter-circularly-shaped, round profile corners by the aid of the cutting rollers extended to the full profile width, so that a rectangular overall profile will indeed be achieved.

At the same time, the provision of extendible end portions of the cutting rollers enables the end portions to be retracted again so as to reduce the width of the cutting rollers and facilitate the maneuvering of the heading machine when moving in the road.

In order to cut away the round profile corners as completely as possible and safely seize all of the cutting profile gussets, it is provided according to a preferred further development that the cutting rollers each have a diameter corresponding to at least one fifth, preferably at least one fourth, of the cutting diameter of the cutting heads. Accordingly large diameters of the cutting rollers will enable an especially good approximation to the intended rectangular profile shape.

In order to enable an adaptation of the size of the cutting profile to the respective requirement, it is provided according to a preferred further development that the cutting heads are provided with cutting tools which are adjustable or extendible in the radial direction. This will enable the adjustment of the size of the circular profile driven by the individual, rotating cutting heads. Another advantage of this configuration resides in that the cutting tools, for instance, for an enhanced maneuverability of the heading machine, can be displaced radially inwards during the back-travel from the driven tunnel in order to thereby reduce the required space and, hence, the risk of collisions with the tunnel walls or the like.

In order to adapt also the cutting rollers provided according to the invention to the respective profile dimensions and, in particular, profile height, the configuration is advantageously devised such that each cutting roller is separately hinged to the cutting boom or frame in a height-adjustable manner.

Further adaptability will result from a preferred further development in which the cutting boom or frame is arranged to be adjustable relative to the travelling mechanism in the vertical direction. Such a configuration will enable the simultaneous adjustment of all the cutting means fixed or hinged to the cutting boom or frame, so that both the rotating cutting heads and the two cutting rollers will accordingly be jointly adjustable in terms of height. In this manner, an improved profile adaptation will be enabled, with a number of options for adapting the overall profile to the respective requirements and conditions resulting, in particular, in combination with the two laterally extendible cutting rollers.

The actuation of the individual cutting units usually is effected via a central drive and appropriate gears. Such a central drive, in the heading machine according to the invention, can, for instance, be used to drive the at least two rotating cutting heads. However, according to a preferred further development, the two cutting rollers are each driven separately, the cutting rollers each comprising an individual drive. This enables a better mutual tuning of the energy expenditure for the individual cutting tools than would be the case with a central drive including driving shafts. Central drives, in particular, involve the problem that, if one of the cutting units driven by the central drive spins because of a defect or other unforeseeable circumstances, the driving force will automatically be distributed to the remaining drive units, which are frequently not dimensioned for such elevated driving forces and, thus, may become damaged. In the event of individual drives for the cutting units and, in particular, for the two cutting rollers, such problems will not occur, since the drive can each be separately controlled.

As already mentioned in the beginning, a configuration is, more-over, preferred, in which the cutting tools are arranged on the cutting heads in a manner that cutting tools of one of the cutting heads engage between cutting tools of the other one of the cutting heads during rotation such that the circular areas of the respective cutting profiles overlap one another. With such a configuration, the cut gussets remaining between the mutually overlapping circular-area-profiles will be accordingly smaller so as to facilitate the trimming procedure.

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 side view of the heading machine according to the invention;

FIG. 2 is a top view on the heading machine according to the invention;

FIG. 3 is a front view of the heading machine;

FIG. 4 depicts a cutting profile as is obtainable by a heading machine known from the prior art, including a trimming chain; and

FIG. 5 depicts a cutting profile to be achieved by the heading machine according to the invention.

In FIG. 1, a heading machine is denoted by 1 and comprises a travelling mechanism 2. The travelling mechanism in this case is configured as a crawler mechanism. On the cutting boom 3, which can be adjusted in the vertical direction in the sense of double arrow 4 by an appropriate adjusting apparatus, cutting bodies 5 are mounted, which are rotationally driven about an axis of rotation 6.

Behind the cutting body 5 are arranged a cutting roll 8 to be positioned on the roof 7, and a cutting roll 10 to be positioned on the floor 9. The cutting rolls 8 and 10 are fixed to a pivot arm 11 or 12, respectively, which is pivotable relative to the cutting boom 3 about an axis 13 or 14, respectively. Hydraulic cylinders 15 and 16, respectively, serve as pivot drives. Each of the two cutting rolls 8 and 10 is associated with an individual drive 17 or 18, respectively.

FIG. 1 further depicts a hauling means 19, which extends in the longitudinal direction of the machine as far as to beyond the end of the heading machine 1 and comprises a pivotable delivery portion. Also illustrated is a support frame 22 which is coupled to the machine frame by the aid of a hydraulic cylinder 21 and capable of being trailed, and which carries anchor boring and setting devices 23 as well as respective supporting devices 24.

From the illustration according to FIG. 2, it is apparent that a total of two rotating cutting heads 5 are adjacently arranged on the front end of the machine. The cutting roller 8 comprises a central roller portion 27 as well as two extendible end portions 25. The end portions 25 are extendible in the sense of double arrows 26 for the adjustment of the cutting width of the cutting roller 8. The rotational drive for the cutting roller 8 is again denoted by 17, wherein the central portion 27 of the cutting roller 8 is driven by a gear not illustrated in detail, and the extendible end portions 25 are connected with the central portion 27 by the aid of a positive connection in a manner secured against rotation, yet displaceable in the direction of the axis of rotation of the cutting roller 8. The adjustment device for the vertical readjustment of the cutting boom 3 is denoted by 38.

In the front view according to FIG. 3, the individual cutting units are more clearly visible. The two cutting heads 5 each comprise a plurality of cutting tools and, in particular, cutting knives 28, which are adjustable in the radial direction in the sense of double arrows 29 in order to change the size of the respective circular profile to be achieved. The two cutting heads 5 are preferably driven in mutually opposite directions, with the individual cutting tools 29 accordingly engaging in each other during rotation so as to produce the overlaps of the individual circular profiles illustrated in FIG. 5. From FIG. 3, it is further apparent that the two cutting rollers 8 and 10 each carry a plurality of cutting tools such as, for instance, cutter bits 30, both on the central roller portion 27 and on the extendible end portions 25. As is clearly apparent from FIG. 3, the end portions 25 are extendible in the sense of double arrows 26 in a manner that a substantially rectangular profile will be driven.

FIGS. 4 and 5 depict cutting profiles to be obtained according to the prior art and by the present invention, respectively. Parallel cuts 31 and 32 are each illustrated, the heading machine initially making a cut 31 and, subsequently, a cut 32 parallel to the former. In FIG. 4, the two profiles cut by the rotating cutting heads are denoted by 33, the profile gusset 35 being cut away by a trimming device in the form of a trim chain 34. Overall, a rectangular cutting profile is, however, not achievable by a heading machine of this type. This is why a region overlapping with the cut 31 has to be covered by the subsequent cut 32 so as to achieve an altogether reduced overall profile width.

FIG. 5 depicts the overall profile to be achieved by the heading machine according to the invention. The circular profiles to be achieved by the two cutting heads 5 are again denoted by 33, defining a profile width a. The remaining profile gussets 35 as well as the likewise remaining round corners 36 in this case are cut away by the aid of the cutting rollers 8 and 10, whose widths correspond to the profile width a on account of the extended end portions 25, and whose profiles are denoted by 37. Thus, a rectangular overall profile is achievable. The subsequent cut 32 can, therefore, immediately follow the first cut 31 so as increase the extraction efficiency.

Claims

1. A heading machine comprising a travelling mechanism and a cutting boom or frame, wherein

the cutting boom or frame carries at least two rotating cutting heads having axes of rotation extending in a heading direction or which enclose acute angles with the heading direction and which, together, define a cutting profile having a profile width, as well as two cutting rollers arranged substantially parallel and behind the cutting heads and adapted to being positioned on a floor and on a roof, respectively,

each of the cutting rollers (8, 10) comprise end portions (25) which are extendible to a width (a) of the cutting profile for formation of a substantially rectangular cutting profile,

each of the cutting rollers. (8, 10) is separately hinged to the cutting boom (3) or frame in a height-adjustable manner, and

each of the cutting rollers (8, 10) has a diameter corresponding to at least one fifth of the cutting diameter of the cutting heads (5).

2. A heading machine according to claim 1, wherein each of the cutting rollers (8, 10) has a diameter corresponding to at least one fourth of the cutting diameter of the cutting heads (5).

3. A heading machine according to claim 1, wherein the cutting heads (5) are provided with cutting tools (28) which are adjustable or extendible in the radial direction.

4. A heading machine according to claim 1, wherein the cutting tools (28) are arranged on the cutting heads (5) in a manner that cutting tools (28) of a first one of the cutting heads (28) engage between cutting tools (28) of a second one of the cutting heads during rotation such that circular areas of respective cutting profiles (33) overlap one another.

5. A heading machine according to claim 1, wherein the cutting rolls (8, 10) each comprise an individual drive (17, 18).

6. A heading machine according to claim 1, wherein the cutting boom (3) or frame is arranged to be adjustable relative to the travelling mechanism (2) in a vertical direction.

7. A heading machine according to claim 2, wherein the cutting heads (5) are provided with cutting tools (28) which are adjustable or extendible in the radial direction.

8. A heading machine according to claim 2, wherein the cutting tools (28) are arranged on the cutting heads (5) in a manner that cutting tools (28) of a first one of the cutting heads (28) engage between cutting tools (28) of a second one of the cutting heads during rotation such that circular areas of respective cutting profiles (33) overlap one another.

9. A heading machine according to claim 3, wherein the cutting tools (28) are arranged on the cutting heads (5) in a manner that cutting tools (28) of a first one of the cutting heads (28) engage between cutting tools (28) of a second one of the cutting heads during rotation such that circular areas of respective cutting profiles (33) overlap one another.

10. A heading machine according to claim 2, wherein the cutting rolls (8, 10) each comprise an individual drive (17, 18).

11. A heading machine according to claim 3, wherein the cutting rolls (8, 10) each comprise an individual drive (17, 18).

12. A heading machine according to claim 4, wherein the cutting rolls (8, 10) each comprise an individual drive (17, 18).

13. A heading machine according to claim 2, wherein the cutting boom (3) or frame is arranged to be adjustable relative to the travelling mechanism (2) in a vertical direction.

14. A heading machine according to claim 3, wherein the cutting boom (3) or frame is arranged to be adjustable relative to the travelling mechanism (2) in a vertical direction.

15. A heading machine according to claim 4, wherein the cutting boom (3) or frame is arranged to be adjustable relative to the travelling mechanism (2) in a vertical direction.

16. A heading machine according to claim 5, wherein the cutting boom (3) or frame is arranged to be adjustable relative to the travelling mechanism (2) in a vertical direction.