Note: Descriptions are shown in the official language in which they were submitted.
7~57
-- 2 --
This invention relates to the field of coupliny means for
connections to a rod. More particularly, this invention relates a
coupling device for coupling a taphole drilling or forming rod, as
employed in furnace equipment, such as a shaft furnace, to a
percussion machine employed for extraction of the rod from the
taphole.
A recent development in the tapping of molten metal
furnaces involves 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
closedr a rod is reinserted into the plugging mud in the taphole
rod. The rod is extracted from the tap~ole by being coupled or
connected to a percussion machine which is operated to extract the
rod.
1~ 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 in~eres~ 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 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.
;7
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
su~fers 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 oE being reused aftex 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
lS provided a coupling device including first housing means
having a chamber therein for receiving a rod to be coupled;
~L%0~57
jaw means in said chamber, said jaw means being movabl~
between a first position of disengagment 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 materiel
of the rod;
second housing means; and
pEessurized fluid actuating means in said second housing
means and connected to said jaw means for moving said jaw means
10 between said first and second positions.
There is also provided a coupling devlce for coupling a
working tool to a taphola rod of a molten metal vessel, the
coupling devi.ce 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 ha~ing 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
o~ 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
pressurized fluid actuating means in said second housing
means and
.~ ~IL2~7~5~7
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 oE said jaw means.
The coupling device of the presen-t 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
10 specially desiyned 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 interchangeabl~. The term"drilling rod"
is conventional from the prior technology in which the
15 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 displacable 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
~han the diameter of the taphole 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.
,
:~207~57
-- 6
In the second position, the jaws bite into and lock onto the
rod, whereby the rod may be extracted from the taphole, pre-
ferably 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 wïth respec-t to the
central axi~ of the coupling device, so that the piston rods
converge toward the opening in the first housing through 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 r 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 sapable 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
~ 7RS7
--7--
of the str~lcture, rather than being inclined as in the o-ther
embodiment.
In bo-th 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 unders-tood by those skilled
in the art from the followin~ detailed description and
drawings.
Referring now to the several FIGURES in the drawings,
wherein like elements are numbered alike in the several
FIGURE~:
FIGURE 1 is a sectional longitudinal or elevation view
through a first embodiment o~ the coupling device of the
present invention, wi-th 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,
2~ showing the structure in FIGURES 1, 2 and 3.
FIGURE 5 is a partial sectional view showing a first
jaw structure.
FIGU~E 6 is a partial sectional view similar to
~IGURE 5 showing a second jaw structure.
q
--8--
FIG~RE 7 is a partial sectional view similar to
FIGURES 5 and 6 showing a third jaw struc-ture.
FIGURE 8 is a view showing appara-tus 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 embddiment 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 pistons and cylinde~s are located
and another block or housing 12 having an internal
compartment 20 in which the taphole rod and jaws are
located. Housing 12 receives a taphole or drill rod 14
i~ through an aperture or axial opening 16. Opening 16 is
circular in cross section with its center o~ the axis "O"
of the coupling mechanism; and the a~is o rod 14 is also
coaxial with axis "O" when the rod is engaged in the
coupling device. To assist in location and entry of taphole
rod 1~ into the coupling mechanism throu5h opening 16, the
front end of housing 12 has a concave or funnel shaped
recess 18 to provide a lead in passage for the taphole rod
1~ .
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
~ 7 ~2~
_9_.~
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 grippiny engagement with
rod 14. ~he two outer walls 26 and 28 of chamber 20 converge
toward axis "0" in the direction of opening 16; and these
ou~er 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 si~ed 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 wa~ of a central passageway 30,
coaxial with axis "0", for mounting the coupling device on
the woxking 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
2~57
--10--
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 ~0 are posi~ioned around the piston rods 44 and 46
to drive the pistons 36 and 38 back to the left from the
FIG~RE 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. ~ssuming that the
drilling rod or taphole 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 of the couplirlg d~vice o~ the present invention.
21D7~57
The coupling device (which is a-ttached to the percussion
tool~ is first positioned on rod 1~, with rod 14 passing
through opening 16 to the point where the back wall oE
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., FIGUREl) 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 ~8 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 ~act, carried out
by the operation of the percussion tool while pistons 36 and
38 remain pressurizad. Under the simultaneous action of the
pneuma-tic 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 ~rom ~he position shown in FIGU~E 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 obli~ue sliding movement of the jaws.
'-:
~20~ 7
-12-
An automatic and self-clamping ac-tion 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.
Wi-th the coupling to the taphole or drilling rod having
been made as described in connection with FIGURES 1 r 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 disengagement, the left side of
pistons 36 and 38 are ven-ted to atmosphere (i.e., the
pressurized fluid is removed), whereby the compressed springs
48 and 50 return the pistons, piston rods and jaws from the
position of FIGURE 3 to the position of FIGURF 1. If the
force of springs 48 and 50 should, for sorne 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 lO and 12 are separable from each other in
order to afford access to chamber 20 for purposes such as
-13-
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 an 24 a 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 con-
figuration, edges 22a and 24a will be straight edges formed
by the junction of inclined surfaces on the jaws. ~hat
simplest configuration is shown in FIGURES 4 and 7, with
FIGUR~ 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 ~nd 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.
::,
~L~Q7~7
-14-
In the FIGURE ~ construction, the jaws 22 and 24 aLe
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 xollers 54 and
56 on the rods. The presence of the rollers 5~ and 56 in
place of jaws 22 and 24 results in greater fle~ibility
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 pivots 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 pneumatic pressurized fluid from
~0 the left toward the right as seen in FIGURE 9 to pivot
th~ 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 cloc~wise,
respectively, around their fulcrums 70 and 72 to effect
locking engagement with and coupling to the taphole rod
~0~ 7
--15--
when pressurized fluid is introduced to the left of
pistons 7~ and 80. Jaw 66 will be pivoted counterclockwise
and j~w 68 will be pivoted clockwise to bring the jaws into
contact with the outer surface of rod 14; and the
simultaneous action of the pistons and the traction on rod
: 14 will 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 6B during
retraction.
The disengagement of rod 14 from the coupling device
of the FIGURE 9 embodiment following extraction of the rod
,r
-16-
from the taphole is effected in the same manner as in the
embodimen-ts 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 14
from 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 he 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 FIGUR~S 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 recogni~ed 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 o 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
2~ the coupling device. Thus, the rod 14 may be economically
produced. A further advantage is that the rods may be out
of round and vary in diameter by up to 15 millimeters, and
the device of the present invention will still function
effectively~
