GB2116898A - Device for coupling a shaft furnace tap hole drilling rod to the working tool of a drilling machine - Google Patents

Abstract

A coupling device, for coupling a shaft furnace tap hole drilling rod 14 to a drilling machine for the extraction of the rod 14, includes piston operated jaws 22, 24 slidable inside a housing 12 from a position out of engagement with a drilling rod 14 to a position in gripping engagement therewith. The pistons 36, 38 for pushing the jaws 22, 24 are housed in the chambers 32, 34 of a block 10. They are driven, against their respective spring force, such as by feeding compressed air into the chambers 32, 34. The jaws 22, 24 thus slide and grip the rod 14 whereafter the entire device can be moved leftwardly (as seen in the figures) to extract the rod 14. The jaws may be in the form of slidable gripping rollers or pivotable cams. The jaws are made of a material which is harder than that of the rod 14. <IMAGE>

Description

SPECIFICATION Device for coupling a shaft furnace tap hole drilling rod to the working tool of a drilling machine This invention relates to the field of the extraction of molten metal from a furnace such as a shaft furnace.

More particularly, this invention relates to a coupling device for coupling a taphole drilling orforming rod to a percussion machine.

A recent development in the tapping of molten metal furnaces involved process and apparatus in which a rod is left in the taphole between two successive tapping operations. To open the taphole, the rod is extracted; and when the taphole is to be closed, a rod is reinserted into the plugging mud in the taphole rod. The rod is extracted from the taphole by being coupled or connected to a percussion machine which is operated to extract the rod.

The process and apparatus for opening the taphole by means of a drill rod left in the taphole between two successive tappings is arousing increasing interest in comparison with the conventional method in which tapholes are drilled by means of a drill bit. Reference is hereby made to Belgian Patent Number 890 951,for for a discussion of details of this taphole processing and its advantages and also for a discussion of equipment to be used in the process. As discussed in Belgian Patent 890 951, this taphole opening method requires that the drill rod embedded in the taphole be coupled to an appropriate machine, such as a percussive type drilling machine, to extract the rod from the taphole when it is desired to open the taphole.

Various systems and apparatus have been proposed for effecting the required coupling between the taphole rod and the drilling machine. Most of these prior apparatus and methods, however, require manual action on the part of the operator in making the connection. This, of course, involves a risk to the safety of the operator in view of the danger of accidents arising out of the position in which this manual action has to be taken. To overcome these drawbacks, a coupling device has been proposed which is capable of being automatically and remotely operated from a control station to eliminate the requirement for manual intervention by the operator. However, that proposed system and apparatus still suffers from two significant drawbacks. First, the apparatus of that prior system requires a specially designed taphole rod provided with a notch at the end to be engaged by the coupling device.The second drawback is that the requirement for specially designed and formed taphole rod increases the cost of the rods. The second drawback is all the more serious, since the drilling rod is usually used only once and is not capable of being reused after it has been extracted from the taphole. Thus, any increased expense related to the taphole rod is multiplied each time a rod is consumed.

The purpose of the present invention is to eliminate the above discussed and other problems and disadvantages of the prior art. In accordance with the present invention, there is provided a coupling device including first housing means having a chamber therein for receiving a rod to be coupled; jaw means in said chamber, said jaw means being movable between a first position of disengagement from the rod and a second position of engagement with and penetration into the rod; said jaw means being of a material harder than the material of the rod; second housing means; and actuating means in said second housing means and connected to said jaw means for moving said jaw means between said first and second positions.

There is also provided a coupling device for coupling a working tool to a taphole rod of a molten metal vessel, the coupling device including: first housing means having a chamber therein for receiving the taphole rod to be coupled; entrance means at the front of said first housing means for passage of said taphole rod into said chamber; said chamber having first and second spaced outer walls symmetric about an axis of the coupling device, said first and second walls being inclined inwardly toward said axis and said entrance means; jaw means in said chamber and adapted to move along said first and second spaced outer walls between a first position of disengagement with the taphole rod and a second position of engagement with and penetration into said taphole rod; second housing means connected to said first housing means and adapted to be connected to the working tool; and actuating means in said second housing means and connected to said jaw means for moving said jaw means along said first and second walls of said chamber between said first and second positions, said actuating means being aligned with the direction of motion of said jaw means.

The coupling device of the present invention achieves the desired coupling between the drilling tool and the taphole rod in an effective and reliable manner and without requiring any special design of the taphole rod, thus eliminating the substantial disadvantage of additional cost requires for specially designed taphole rods. In describing and discussing the present invention, reference .will be made to a "taphole rod" or a "drilling rod", and it will be understood that those terms are used interchangeably. The term "drilling rod" is conventional from the prior technology in which the tapholes were actually drilled. In the technology in which the present invention is employed, the "drilling rod" terminology is still used, even though no drilling takes place in the conventional sense; and hence the term "taphole rod" maybe more appropriate.

The coupling device of the present invention has at least two movable jaws arranged summetrically around the axis of a chamber which receives the taphole rod. The jaws are made of a material harder than the material of the taphole rod, and the jaws are displaceable under the action of pneumatically operated piston means between a first, or retracted, position of the jaws in which the distance between the jaws is greater than the diameterofthetaphole rod, and a second, or advanced, position of the jaws in which the distance between the jaws is smaller than the diameter of the taphole rod. In the second position, the jaws bite into and lock onto the rod, whereby the rod maybe extracted from the taphole, preferably by the action of a percussive drill tool to which the coupling is also connected.The coupling includes a first block or housing in which the jaws are located and into which the taphole rod extends, and a second block or housing in which the pneumatic pistons are located. The second block or housing also contains structure for connection to the percussive drill tool.

In a first embodiment of the invention, the pistons and their cylinders are inclined inwardly with respect to the central axis of the coupling device, so that the piston rods converge toward the opening in the first housing throug which the taphole rod passes. The jaws are connected directly to, but not necessarily rigidly on, the ends of the piston rods. The walls of the chamber in the first housing into which the taphole rod extends are preferably oblique and inclined at the same angle as the piston rods, so that they serve to support and guide the jaws.

The jaws may consist of locks attached to the piston rods, with transverse gripping edges on the blocks which engage and bite into the taphole rod.

The jaws may also consist of roller elements capable of rolling or turning on the end of the piston rod. In another embodiment, the jaws consist of locking or cam elements which are pivotal into engagement with the taphole rod by the action of connecting rods extending from the pistons. In this second embodiment, the pistons and piston rods may be aligned parallel to the axis of the structure, rather than being inclined as in the other embodiment.

In both embodiments the jaws are actuated through pneumatically operated pistons which are preferably connected to the same source of compressed air used to operate the percussion drilling tool. Compressed air operates the pistons to effect locking engagement; and return action to disengage the jaws may be effected by return springs and/or compressed air to the other side of the piston.

The above discussed and other advantages of the present invention will be apparent to and understood by those skilled in the art from the following detailed description and drawings.

Referring now to the several Figures in the drawings, wherein like elements are numbered alike in the several Figures: Figure 1 is a sectional longitudinal or elevation view through a first embodiment of the coupling device of the present invention, with the jaws shown in one position.

Figure 2 is a view similar to Figure 1 showing the jaws in a second position.

Figure 3 is a view similar to Figures 1 and 2 showing the jaws and taphole rod in another position.

Figure 4 is a rear elevation view, partly in section, showing the structure in Figures 1,2 and 3.

Figure 5 is a partial sectional view showing a first jaw structure.

Figure 6 is a partial sectional view similar to Figure 5 showing a second jaw structure.

Figure 7is a partial sectional view similar to Figures 5 and 6 showing a third jaw structure.

Figure 8 is a view showing apparatus similar to that of Figures 1,2 and 3 with another embodiment of the jaw structure.

Figure 9 is a sectional elevation view showing a second embodiment of the coupling device of the present invention.

Referring jointly to Figures 1, 2 and 3, the coupling device of the present invention has a block or housing 10 in which the piston and cylinders are located and another block or housing 12 having an internal compartment 20 in which the taphole rod and jaws are located. Housing 12 received a taphole or drill rod 14 through an aperture or axial opening 16. Opening 16 is circular in cross section with its center on the axis "0" of the coupling mechanism; and the axis of rod 14 is also coaxial with axis "0" when the rod is engaged in the coupling device. To assist in location and entry of taphole rod 14 into the coupling mechanism through opening 16, the front end of housing 12 has a concave orfunnel shaped recess 18 to provide a lead in passage for the taphole rod 14.

The interior of block or housing 12 contains chamber 20 which, as can be seen in Figure 4, has straight vertical side walls. When taphole rod 14 has been completely inserted into the coupling mechanism, compartment 20, as best seen in Figure 1, then consists of two cavities, one each positioned above and below the rod 14. Jaws 22 and 24, which are designed to grip rod 14, are positioned in these two cavities. The jaws 22 and 24 are designed and shaped so as to move within these cavities for gripping engagement with rod 14. The two outer walls 26 and 28 of chamber 20 converge toward axis "O" in the direction of opening 16; and these outer walls, together with the side walls of the upper and lower portions of chamber 20 guide and support the jaws 22 and 24 which are sized to be in sliding contact engagement with the walls of these chambers.Jaws 22 and 24 are provided , respectively, with inner gripping edges 22a and 24a for locking engagement with the rod 14.

Housing 10 is configured to be integrally attached to an appropriate working tool, not shown, such as e percussion type taphole drilling machine. In the embodiment shown, this connection may be effected by way of a central passageway 30, coaxial with axis "0", for mounting the coupling device on the working tool. The mounting of the coupling device on the working tool may be accomplished by known means, such as a key type or bayonet type securing device, or by the apparatus disclosed in Belgian Patent 890951.

Block or housing 10 has a pair of cylinders 32 and 34 in which a pair of pistons 36 and 38 and their piston rods 44 and 46 are mounted for sliding movement. Piston rods 44 and 46 are connected, respectively, to jaws 22 and 24. "0" rings or other known seals 40 and 42 provide fluid tight sealing of the pistons in their respective chambers so that the pistons may be activated by pneumatic or other pressurized fluid. The left side of each piston is connected to a source of compressed air (not shown) by appropriate pipes or conduits (also not shown).

Compressed air to operate the cylinders may be obtained from the pneumatic circuit of the percussion tool to which the coupling device is connected.

The application of pressurized fluid to the left of each of the pistons 36 and 38 causes the pistons to move to the right from the position shown in Figure 1 to the positions shown in Figures 2 and 3, successively.

Helical return springs 48 and 50 are positioned around the piston rods 44 and 46 to drive the pistons 36 and 38 back to the left from the Figure 3 position to the Figure 1 position when the pressurized air is removed from the left side of the pistons.

In the embodiment shown in Figures 1 through 3, it is essential that the pistons and piston rods be positioned obliquely, i.e., inclined, with respect to the axis "0" and in line with the direction of movement of jaws 22 and 24 relative to axis "0" parallel to the walls 26 and 28 of chamber 20.

Still referring to Figures 1 through 3, the operation of the coupling device will be described. Assuming that the drilling rod ortaphole rod is in place with the taphole closed and it is desired to extract the rod from the furnace, the percussion machine must be connected to the taphole rod 14 to extract the rod.

This is effected by means ofthe coupling device of the present invention. The coupling device (which is attached to the percussion tool) is first positioned on rod 14, with rod 14 passing through opening 16 to the point where the back wall of chamber 20 is brought into abutting contact with the end of rod 14.

In this position, and with the pistons and jaws 22 and 24 being in the unactivated (i.e., Figure 1) state, the jaws 22 and 24 are not in contact with rod 14.

Pneumatic pressure is then introduced into the left side of pistons 36 and 38 to drive the pistons to the right while compressing springs 48 and 50. Jaws 22 and 24 move along walls 26 and 28 to the intermediate position shown in Figure 2 where the gripping surfaces 22a and 24a of the jaws come into gripping contact and engagement with rod 14. From that point on (i.e., from the intermediate position shown in Figure 2) traction can then be exerted on rod 14 by moving the coupling device to the left as viewed in the drawings. This displacement of the coupling member is, in fact, carried out by the operation of the percussion tool while pistons 36 and 38 remain pressurized.Under the simultaneous action of the pneumatic pressure on pistons 36 and 38 and the action of the percussion tool associated with the traction or tension exerted by the jaws 22 and 24 on rod 14, the jaws are caused to move from the position shown in Figure 2 to the position shown in Figure 3, while at the same time the jaws are driven into biting engagement with the outer layer of the rod 14. That is, the surfaces 22a and 24 a of the jaws actually bite or penetrate into the outer surface of rod 14 for a slight distance because of the oblique sliding movement of the jaws. An automatic and self-clamping action takes place in which the gripping action between the jaws and taphole rod increase in proportion to the tractive force exerted on the rod.This automatic clamping not only insures extremely reliable operation, but also prevents the rod 14 from inadvertently slipping out of the coupling device. It is to be noted that for the device to function properly, the two jaws 22 and 24 must be made out of material harder than that of rod 14, so that the biting effect described and illustrated with respect to Figure 3 will occur.

With the coupling to the taphole or drilling rod having been made as described in connection with Figures 1,2 and 3, the taphole may then be opened by removal of the rod from the taphole by further operation of the percussion device.

As indicated previously, it is necessary to replace the taphole rod after it has been extracted from the taphole. Thus, the taphole rod must be disengaged from the coupling device. To effect this disengage ment, the left side of pistons 36 and 38 are vented to atmosphere (i.e., the pressurized fluid is removed), whereby the compressed springs 48 and 40 return the pistons, piston rods and jaws from the position of Figure 3 to the position of Figure 1. If the force of springs 48 and 50 should, for some reason, be insufficient to return the pistons, rods and jaws, rod 14 can be manually pushed to the left to disengage the jaws, or the percussion tool can be actuated to the right, so that its vibrations will release rod 14.

Housings 10 and 12 are separable from each other in order to afford access to chamber 20 for purposes such as changing the jaws when they are worn. To this end, the housings 10 and 12 are connected together by bolts 52 (see Figure 4); and these housings may be separated whenever it is desired to replace the jaws.

The inner or gripping edges 22a in 24a of jaws 22 and 24 must be sufficiently sharp to enable them to bite into drilling rod 14, as shown in Figure 3. In the simplest configuration, edges 22a and 24a will be straight edges formed by the junction of inclined surfaces on the jaws. That simplest configuration is shown in Figures 4 and 7, with Figure 7 depicting the jaw having penetrated into the surface of rod 14. It is, nevertheless, preferable for the edges 22a and 24a to be shaped to provide wider contact with the drilling rod than is effected in the Figure 4 and 7 configuration. Figures 5 and 6 show two variations of the edge arrangement to achieve that wider contact. In Figure 5 the edges 22a and 24a have a concave shape which is essentially complimentary to the shape of the outer surface of rod 14.In the Figure 6 embodiment, the edges 22a and 24a are each made in two convex portions (i.e., having convex portions arching from the center of the jaw to each edge). With the configuration of Figure 6, contact between the jaws and the rod in the position corresponding to the Figure 2 position is obtained at two points on two sides of a vertical axis of symmetry of the rod and jaws, thus enhancing both the gripping of the rod and the self centering action of the jaws.

Referring now to Figure 8, a variation of the coupling device of the present invention is shown. In the Figure 8 construction, the jaws 22 and 24 are replaced by rollers 54 and 56 rotatably mounted on the ends of rods 44 and 46. The ends of rods 44 and 46 are bifurcated in order to receive and mount the rollers 54 and 56 on the rods. The presence of the rollers 54 and 56 in place of jaws 22 and 24 results in greater flexibility in the choice of the angle of inclination for the walls 26 and 28. In all other respects, the coupling device of Figure 8 is the same as that described with respect to Figures 1,2 and 3, both in construction and function.

Referring now to Figure 9, still another embodiment of the present invention is shown. In the Figure 9 embodiment, the jaws consist of a pair of pivoting jaw or cam elements 66 and 68 which are mounted on pivot 70 and 72 in a chamber 64 in a block or housing 60. Another block or housing element 62 (which, as in the preceding embodiments, is affixed to the drilling machine) has a pair of cylinders 74 and 76 with pistons 78 and 80. Pistons 78 and 80 are actuated by penumatic pressurized fluid from the left toward the right as seen in Figure 9 to pivot the jaws or cams 66 and 68 into locking engagement with rod 14. The piston rods 86 and 88 pass into compartment 60 and are articulated via connecting rods 90 and 92 to the corresponding pivoting jaws 66 and 68, respectively.The sliding movement of the pistons 78 and 80 causes the jaws 66 and 68 to pivot counterclockwise and clockwise, respectively, around their fulcrums 70 and 72 to effect locking engagement with and coupling to the taphole rod when pressurized fluid is introduced to the left of pistons 78 and 80. Jaw 66 will be pivoted counterclockwise and jaw 68 will be pivoted clockwise to bring the jaws into contact with the outer surface of rod 14; and the simuitaneous action of the pistons and the traction on rod 14will move the jaws 66 and 68 into the position shown in Figure 9 where the jaws bite into the rod 14. This is the position corresponding to that shown in Figure 3, which occurs when the drilling rod 14 is retracted from the taphole.When the left side of pistons 78 and 80 are vented to ambient, the springs 82 and 84 will drive the pistons to the left, whereby jaws or cams 66 and 68 will be pivoted in the reverse directions to disengage the jaws from rod 14, this being the position corresponding to that shown in Figure 1.

It will be noted that in the Figure 9 embodiment the pistons and piston rods may be positioned parallel to axis "0" rather than being inclined with respect to the axis. It is also to be noted that in the embodiment of Figure 9 the drilling rod 14 also undergoes a self-clamping action as in the previously described embodiments. That is, the greater the tractive force exerted on rod 14, the greater will be the distance to which the jaws 66 and 68 penetrate the peripheral surface of rod 14, so that there is no risk that rod 14 will slide between the jaws 66 and 68 during retraction.

The disengagement of rod 14 from the coupling device of the Figure 9 embodiment following extraction of the rod from the taphole is effected in the same manner as in the embodiments discussed previously.

In order to prevent the jaws 66 and 68 from pivoting into a position perpendicular to the axis of rod 14, which would make it extremely difficult to release the rod 14from the coupling device, the front or right walls of chamber 64 can be constructed at a moderate angle of inclination so that the extreme position of jaws 66 and 68 on engagement with rod 14 may be approximately the position corresponding so that shown in Figure 9.

It is also to be noted that the jaws of the Figure 9 embodiment may be of different shapes, such as described with regard to Figures 5 through 7; and the jaws of all embodiments may be of additional alternative shapes and each may be provided with two or more transverse engaging edges.

As will be recognized and understood, the coupling apparatus of the present invention is novel in its structure and operation; and it has the special advantage over the prior art in that it does not require any modification of the end of rod 14 which is to be engaged by the coupling device. That is, the end of rod 14 to be engaged by the coupling device may be cylindrical and smooth and does not have to be provided with special slots or grooves for engagement with the coupling device. Thus, the rod 14 may be economically produced. Afurther advantage is that the rods may be out of round and vary in diameter by up to 15 millimetres, and the device of the present invention will still function effectively.

Claims (18)

1. A coupling device for coupling to a rod, the coupling device including: first housing means having a chamber therein for receiving a rod to be coupled; jaw means in said chamber, said jaw means being movable between a first position of disengagement from the rod and a second position of engagement with and penetration into the rod; said jaw means being of a material harder than the material of the rod; second housing means; and acutating means in said second housing means and connected to said jaw means for moving said jaw means between said first and second positions.

2. A coupling device as claimed in claim 1, wherein the coupling device has an axis, and said jaw means travel in a direction inclined with respect to said axis between said first and second positions.

3. A coupling device as claimed in claim 2, wherein said jaw means includes first and second jaw elements spaced symmetrically about said axis, each of said jaw elements having a straight gripping edge orthogonal with respect to said axis.

4. A coupling device as claimed in claim 2, wherein said jaw means includes first and second jaw elements spaced symmetrically about said axis, each of said jaw elements having a concave gripping surface.

5. A coupling device as claimed in claim 2, wherein said jaw means includes first and second jaw elements spaced symmetrically about said axis, each of said jaw elements having a pair of convex gripping surfaces.

6. A coupling device as claimed in claim 2, wherein said jaw means includes first and second roller elements rotationally mounted to said actuating means.

7. A coupling device as claimed in claim 1, wherein said jaw means includes first and second cam elements spaced symmetrically about said axis, each of said cam elements being mounted in said chamber for pivotal movement.

8. A coupling device as in claim 7, wherein said actuating means includes first piston and piston rod means positioned parallel to said axis and linkage means connecting said first piston rod to said first cam element and second piston and piston rod means positioned parallel to said axis and linkage means connected to said second piston rod to said second cam element.

9. A coupling device as claimed in any one of claims 1 to 6 wherein the coupling device has an axis and said chamber means has a pair of outer walls inclined inwardly with respect to said axis, said walls guiding said jaw means to travel to a direction inclined with respect to said axis between said first and second positions.

10. A coupling device for coupling a working tool to a taphole rod of a molten metal vessel, the coupling device including: first housing means having a chamber therein for receiving the taphole rod to be coupled; entrance means at the front of said first housing means for passage of said taphole rod into said chamber; said chamber having first and second spaced outer walls symmetric about an axis of the coupling device, said first and second walls being inclined inwardly toward said axis and said entrance means; jaw means in said chamber and adapted to move along said first and second spaced outer walls between a first position of disengagement with the taphole rod and a second position of engagement with and penetration into said taphole rod; second housing means connected to said first housing means and adapted to be connected to the working tool; and actuating means in said second housing means and connected to said jaw means for moving said jaw means along said first and second walls of said chamber between said first and second positions, said actuating means being aligned with the direction of motion of said jaw means.

11. A coupling device as claimed in claim 10, wherein said jaw means includes first and second jaw elements, said first jaw element being guided by said first outer wall and said second jaw element being guided by said second wall element; and said actuating means includes first piston and piston rod means inclined along a line parallel to said first outer wall and connected to said first jaw element and second piston and piston rod means inclined along a line parallel to said second outer wall and connected to said second jaw element.

12. A coupling device as claimed in claim 11, wherein said first and second jaw elements are spaced symmetrically about said axis, each of said jaw elements having a straight gripping edge orthogonal with respect to said axis.

13. A coupling device as claimed in claim 11, wherein said first and second jaw elements are spaced symmetrically about said axis, each of said jaw elements having a concave gripping surface.

14. A coupling device as claimed in claim 11, wherein said first and second jaw elements are spaced symmetrically about said axis, each of said jaw elements having a pair of convex gripping surfaces.

15. A coupling device as claimed in claim 11, wherein said jaw elements are first and second roller elements rotationally mounted to said piston rod means.

16. A coupling device as claimed in claim 11, wherein said piston and piston rod means are pneumatically actuated from a first position to a second position to move said jaw elements from said first position thereof to said second position thereof, and further including spring means associated with each of said piston and piston rod means to act on said piston means to urge each of said piston and piston rod means and the jaw elements connected thereto from the second position of each toward the first position of each.

17. A coupling device as claimed in claim 11, wherein said entrance means at the front of said first housing means includes a tapered lead in section and an orifice connected to said chambers, said orifice being centered on the axis of the coupling device.

18. A coupling device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.