The present invention relates to a method for drilling a line of holes, whereby a wall, such as concrete, rock, stone or the like is drilled to form a plurality of successive holes for producing a line of holes therein by periodically operating, at least in one drilling direction, a drilling rig movably mounted on a frame braced with supporting means in connection ^* with the wall, said drilling rig being mounted on the frame so as to be movable in a first guide system extending in its first direction. In order to apply the method particularly in high precision drilling, such as slot drilling, line drilling or the like, the supporting means are fixedly mounted in engagement with the wall by means of fastening elements, such as a screw joint or a like, at three or more, preferably four attachment points, for establishing a first frame position.

For example, a slot is generally produced in rock by using three methods: wire sawing, burning, and creating a slot by drilling. The drilling method as such has been known for a long time, yet there are still few rigs on the market especially intended for slot drilling.

However, the Applicant's current product range includes this type of apparatus, intended to be secured to a wall to be drilled by its four supporting legs. The apparatus comprises a drilling unit movable on a guide system mounted in its longitudinal direction, wherein the positioning of successive holes is effected by using a so-called long indexing rail. The indexing rail includes a clamping bar fixedly mounted on the apparatus frame in the longitudinal direction thereof. The clamping bar includes holes at certain intervals for locking the drilling unit therein in each in-

dividual hole drilling situation. In addition, the drilling conventionally proceeds by initially drilling the first holes of a line of holes and by then drilling the second holes of a line of holes in spaces between the first holes.

For example, tunnel drilling and drilling of individual holes, such as drilling of blast holes, have been effected by using a variety of movable drilling units. ' However, drilling units of this type, which are also included in the Applicant's current product range, cannot be applied to high precision drilling operations due to their mobility and/or boom construction. In drilling operations of this type, the drilling depth is generally appr. six metres and, furthermore, the successive holes must be absolutely parallel to each other, so that the rock material to be extracted after the drilling operations can be removed without substantially breaking the material.

The presently available units are only capable of effecting line drilling in just one direction on a single setting. Therefore, for example in quarries, it is not possible to extend the drilling sufficiently close to the end wall and, thus, the corner must be slotted either by torching or by drilling the holes with another drilling unit. In this case, the torch cutting causes extensive damage to the rock and, furthermore, it is often also forbidden. The use of another drilling unit induces extra costs; furthermore, the drilling work becomes slower and successful drilling is not certain.

It is an object of a method of this invention to provide a decisive improvement on the above drawbacks and thus to raise the level of prior art. In order to achieve this objective, a method of the invention is primarily characterized in that the frame is fitted

with a second guide system extending in a direction substantially different from its first direction, whereby the method is applied by moving and operating the drilling rig, at least in the first position of the frame, in at least one second direction substantial¬ ly deviating from the first direction of the frame for producing at least two lines of holes extending in directions substantially different from each other.

The most important benefits gained by a method of the invention can be said to be simplicity and reliability in operation, which factors are essential requirements for effective drilling work. By applying the method, the drilling work proceeds substantially more rapidly than what can be achieved by the available methods; no separate arrangements are required for corner drilling operations either. Thus, a method of the invention is also capable of substantially improving the productivity over the available methods.

The other non-independent claims directed to a method disclose preferred applications for the method of the invention.

The invention relates also to a drilling apparatus for applying the method. The drilling apparatus is defined in more detail in the preamble of the independent claim directed to a drilling apparatus. The essential characterizing features of the drilling apparatus are set forth in the characterizing clause of the same claim.

By using a drilling apparatus of the invention it is possible to carry out a drilling operation in a simple and reliable fashion also in view of corners in a manner that no other special equipment or procedures are required. By using a drilling apparatus of the invention the control and supervision of drilling

work and operations become much easier than with the available drilling equipment and, furthermore, the drilling apparatus provides a good end result.

The non-independent claims directed to a drilling apparatus disclose preferred embodiments for a drilling apparatus of the invention.

The invention will now be described in more detail with ^* reference made to the accompanying drawing, in which

fig. 1 shows a conventional problem target in drilling work, namely a corner,

fig. 2 illustrates a working example of a drilling apparatus operating according to the method of the invention and drilling a first line of holes, and

fig. 3 shows a corresponding drilling apparatus in the process of drilling a second line of holes.

A drilling apparatus operating according to a method of the invention for drilling a line of holes 2 in a rock wall 1 comprises a frame 3 which is braced on the rock wall 1 by means of supporting elements 4 and which frame 3 supportingly carries a drilling rig 5, movably mounted thereon and operated periodically by means of hydraulically driven, electrical or like power units. In order to use the drilling apparatus especially in high precision drilling, such as slot drilling, line drilling or the like, the supporting elements 4 included in frame 3 are fixedly fastened to attachment points 4a, 4b, 4c, 4d on said wall 1 by means of screw joints 7 for establishing a first position for frame 3. The drilling apparatus includes a first guide system 6a, mounted on frame 3 in its

first direction SI and a second guide system 6b, extending in a direction S2 deviating therefrom, said drilling rig 5 being adapted to be displaceable relative to said guide systems 6a, 6b by means of transfer elements 8 and to be operated in corresponding directions at certain intervals by means of power units for producing at least two lines of holes 2a, 2b extending in directions substantially deviating from each other.

In one preferred embodiment, the drilling rig 5 travels in the first position of frame 3 by means of first transfer elements in the first direction SI of frame 3. The drilling rig is operated by means of power units in the first direction SI at certain intervals, the determination of a hole distance being effected by using indexing elements, such as an indexing rail or a like for producing the first holes of said first line of holes 2a. This is followed by displacing the drilling rig 5 in the same direction, whereby it is operated at certain intervals for producing second holes in said first line of holes 2a. Thus, according to the invention, in connection with a drilling operation effected in the first position of frame 3 said drilling rig 5 is displaced by means of second transfer elements also in the second direction S2 of frame 3, wherein it is operated the same way at certain intervals for drilling holes constituting a second line of holes 2b.

The above described method facilitates a corner drilling shown in fig. 1 so as to avoid the problems involved in the current methods.

Figs. 2 and 3 illustrate one preferred embodiment of a drilling apparatus, wherein said frame 3 includes four braces 4, located in its corners and fastened with screw joints 7 to attachment points 4a, 4b, 4c,

4d included in wall 1. The braces 4 at each end of frame 3 are joined together in second direction S2 by means of first frame members 3a which are joined together in first direction SI by means of a second frame member 3b. The second frame member 3b is accompanied by a first guide system 6a, the drilling rig 5 mounted on a cradle 5a being movable relative thereto by means of first transfer elements. According to the invention, the first frame members 3a are accompanied by a second guide system 6b, the second frame member 3b being movable relative thereto for carrying said drilling rig 5 in direction S2 by means of second transfer elements.

In one preferred embodiment it is possible to make said first direction SI and second direction S2 of frame 3 adjustable relative to each other by arranging at least one of the first frame members 3a and the second frame member 3b so as to be set at an angle adjustable by means of a linkage. If the first frame members 3a of frame 3 extend in diverging longitudinal directions, the second frame member 3b must of course also be variable in its length. Especially in utility rock mining, when drilling e.g. rectangularly shaped rocks, it is possible to effect the drilling in a single drilling position of the drilling apparatus according to one preferred embodiment of a method of the invention. Thus, the drilling apparatus is fixed in its first position, e.g. as shown in figs. 2 and 3, whereby the drilling direction p extends perpendicular¬ ly to a wall 1 to be drilled. The drilling rig 5 is movable on frame 3 within the zone surrounded by attachment points 4a, 4b, 4c, 4d in drilling direction p, whereby the lines of holes to be drilled in first direction SI and second direction S2 of frame 3 can be drilled in wall 1 substantially within the zone or area restricted by attachment points 4a, 4b, 4c, 4d included in wall 1.

A method of the invention can also be applied in a manner that, in order to extend the second line of holes 2b drilled in the first position of frame 3, said frame 3 is detached from wall 1 to be drilled, is pivoted and fixedly re-attached in the second position to wall 1 to be drilled. Thus, the second line of holes 2b drilled in the first position of frame 3 and in its second direction S2 is extended with a drilling effected in the second position of frame 3 in its first direction SI. Thus, the drilling can naturally be continued by carrying the drilling apparatus in drilling direction in its second position forward with the lines of holes 2b continuing in the same direction. As the line of holes 2b is turning to extend in the next direction, the drilling apparatus is re-pivoted to its position corresponding to the next direction of a line of holes.

It is obvious that the invention is not limited to the above embodiment but it can be considerably modified within the scope of the basic conception as a result of the overall extent of a method and a drilling apparatus for the application thereof. Thus, for example, the guide systems and transfer elements can be designed in most diversified fashions, for example by applying the direct-pull principle. Naturally, a drilling apparatus of the invention can also be used for drilling individual holes in most diversified drilling directions.