Field of the invention

The present invention relates to a device for loosening drilling rods, either single rods or connected splicing rods.

Prior art

In connection with the drilling of blow off holes in the ground, in rock or on tunnels, one is often enfaced with the problem that the drilling rod or rods which can be screwed together do a drill string, have become wedged in the drilling hole and therefore are difficult to retrieve from the drilling hole. In this connection it has been suggested to fill diesel oil in the drilling hole for thereby dissolving the masses holding the drilling rods, whereafter an effort is made to pull up the drilling rods by means of the hammer of the drilling machine, i.e.. by means of wires or chains moving the hammer during normal drilling opera¬ tions.

Further, in order to pull up wedged drilling strings there have been used jacks, which has resulted in the tearing off of the drilling strings, and consequently a reduced drilling hole as regards the depth of the predetermined blow off effect. Besides, drilling strings which could have been reused are lost.

Disclosure of the -Invention

The object of the present invention is to eliminate the above mentioned p.voblems, and in connection with a device of the type stated in the preamble, this is resolved according to the invention in that the device comprises a sleeve which is attached to the one end of an auxiliary rod or drilling- rod-like auxiliary rod, and which is adapted for having

inserted thereinto a separate power driven drilling rod.in substantially the opposite direction of the drilling direction of the drilling rod or rods to be loosened.

The separate drilling rod can then be connected to the hammer of an appropriate drilling apparatus, and by means of the hammering effect the wedged drilling rod or rods can be hammered out from their wedging, said sleeve serving as an abutment for the separate drilling rod.

Preferably, the sleeve may be constituted by a pipe piece having an open end and an opposite closed end, said pipe piece being attached at the one end of the auxiliary drilling rod under small angle in relation to the longitudi- nal axis of the drilling rod or rods to be loosened.

Such an auxiliary rod having a sleeve can be adapted to all types of drilling apparatus, preferably of the type which can be turned upsride down, i.e. apparatus wherein the hammer can be turned for drilling in the ground or rock foundation, including upwards or sidewise directions.

In a second embodiment of a device for loosening drilling rods, either as single rods or connected splicing rods, the device according to the invention may comprise a two-armed lever arranged at the one end of a stationary auxiliary rod, the one arm of the lever being adapted for being detachably affixed to the main rod to be loosened, whereas the other arm of the lever being adapted for being influenced by a separate power driven preferably hammer driven drilling rod.

Preferably, the stationary auxiliary rod can then be adapted for being insertec into the ground at an appropriate distance from the drilling rod or rods to be loosened, said lever being constituted by two plates which are pivotably mounted on each side at the upper end of the auxiliary rod.

The two plates can then at their one side carry a detachable

but pivotably mounted guiding piece which can be threaded onto the drilling rod to be loosened, said plates addition¬ ally at their upper outer ends defining abutment areas against a counter force means detachably affixed on the drilling rod.

Preferably, the two plates may at the opposite end of the drilling rod or rods to be loosened define a trough-like abutment area for the drilling end of the separate, preferably hammer power driven drilling rod.

These and further features will appear from the following drawing and the further description, as well as from the attached patent claims.

Brief disclosure of the drawings

Fig. 1 is a schematic view partly in section illustrating a first embodiment of the device according to the invention.

Fig. 2 is a schematic side view of a second embodiment of the device according to the invention.

Fig. 3 is a schematic view as seen in the direction of the arrows III-III of Fig. 2.

Description of embodiments

As appearing from the above and from the attached Figures illustrating embodiments of the device according to the invention, there is in Fig. 1 illustrated a device for loosening drilling rods, either single rods or connected splicing rods.

From Fig. 1 it appears that the device according to the invention comprises a sleeve 2 attached at the one end of an auxiliary drilling rod 1 or a drilling-rod-like auxiliary rod, and adapted for having inserted thereinto a separate

power driven drilling rod 3 in substantially the opposite direction of drilling direction of the drilling rod or rods

4 to be loosened.

Preferably, the sleeve 2 is constituted by a pipe piece having an open end 2a and an opposite closed end 2b, said pipe piece 2 being attached to the one end 1a of the auxiliary drilling rod 1 under a small angle α in relation to the longitudinal direction of the drilling rod or rods 4 to be loosened.

Preferably, the sleeve may have a length of 1 0 cm, whereas it is adapted to an auxiliary drilling rod of approximately 3 m, said length corresponding to a standard length of a drilling rod.

It is to be understood that the auxiliary drilling rod 1 including the sleeve 2 can be attached to the wedged drill 4 by means of hand power, and after the auxiliary drilling rod 1 including the sleeve 2 have been screwed onto the rod 4, the separate power driven drilling rod 3 can be inserted into the sleeve 2, and under the influence of a hammer means

5 of an appropriate drilling apparatus the striking effect of the separate drill 3 against the bottom 2b of the sleeve 2 may drive the wedged drill 4 out of the ground.

It is to be understood that this device can be adapted to all types of drilling apparatuses, preferably of the type which can have its driving means turned upside down, or preferably turned into all directions. The hammer means can then be turned to the direction which may be appropriate, it being related to drilling in the ground or in a rock basement in all directions.

In Figures 2 and 3 there is illustrated a second embodiment of the device according to the invention, the device here comprising a two-armed lever 12 arranged at the one end of a stationary auxiliary rod 11 , the one arm 2a of the lever 12

being adapted for attachably affixing to the drilling rod 14 to be loosened, whereas the second arm 2b of the lever 12 being adapted for being influenced by a separate power driven drilling rod 13.

Appropriately, the stationary auxiliary rod 11 may be adapted for being inserted into the ground at a suitable distance from the drilling rod or rods 14 to be loosened, said lever 12 being constituted by two plates 12x and 12y, as this is specifically illustrated in Fig. 3, wherein said plates 12x and 12y are mutually pivotably mounted at each side 16a and 16b, respectively, of the upper end 11a of the auxiliary rod 11.

At the one side the two plates 12x and 12y carry a detach- ably but pivotably mounted guiding piece 17 which can be threaded onto the drilling rod 14 to be loosened, said plates 12x and 12y at their upper ends constituting abutment areas 18a and 18b, respectively, against a counter force means 19 detachably affixed to the drilling rod 14.

At the other end of the two plates 12x and 12y, i.e. at that end which is opposite the rod 14 to be loosened, said plates carry a trough-like abutment area 20 for the drilling end of the separate hammer power driven drilling rod 13.

Appropriately, the auxiliary rod 11 may be further supported by means of appropriate means 21 connecting the auxiliary rod 11 to for example the base of the drilling apparatus 22, which in turn drives the drilling rod 13.

During operation the drilling apparatus 22 will subject the drilling string 13 to a striking effect, which involves that the arm 12b of the lever 12 will transfer the downwardly directed hammer striking power to the upwardly directed hammer striking power through the arm 12a for the pulling up of the wedged drilling rod 14 through the counter force means 19 of the latter. As the wedged drilling rod 14 is

driven upwardly the counter force means 19 and the guiding 17 can suitably be displaced downwardly along the rod 14 for another engagement and new hammer power interactions.