Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The invention relates to an arrangement for separating a
starter bar from a cast strand in a continuous casting plant
having an arcuate strand-guide part and an approximately horizon-
tal strand-guide part including a cutting means for the cast
strand, in particular in a continuous casting plant for steel
slabs, wherein the starter bar comprises a starter bar head that
is connectable with the cast strand in a direct casting connec-
tion and may be re-used, i.e. a socalled "permanent head", which
is disconnectable from the cast strand by a separating means
arranged in the strand guide, the starter bar being conveyable
out of the strand guide by means of a lifting device.
The utilization of a permanent head is known, for instance,
from German Offenlegungsschrift No. 2,748,690. In this document,
also an arrangement for separating the permanent head from the
cast strand is described. By this arrangement, the hook-shaped
permanent head is moved upwardly transverse to the strand axis,
the hook-shaped permanent head thus getting out of engagement
with the end of the cast strand. Then, the starter bar is moved
away from the cast strand in the direction of the strand axis at
a speed that exceeds the conveying speed of the cast strand, and
the permanent head is lowered again, whereupon the starter bar
can run off along the strand guide without being impeded, until
it is lifted by a crane or the like and placed onto a deposit,
or runs, for instance, onto a pivotable rocker serving as a
deposit.
When using a permanent head it may happen that the permanent
head welds with the cast strand, so that the permanent head can
no longer be easily separated from the cast strand. Care has
therefore had to be taken in continuous casting plants equipped
with permanent heads that even in the case of a welding together
-- 1 --
~P7~ 9
of permanent head - cast strand, a separation of the starter bar
from the cast strand was possible. Such an emergency situation
usually was accommodated by separating the starter bar from the
cast strand by means of the cutting means provided for the cast
strand. Thus, it was necessary to guide the starter bar also
over the strand guiding part provided with the cutting means for
the cast strand, which is designed as a torch cutting roller
table in continuous casting plants for slabs. This results, on
the one hand, if one tries to thread the starter bar from below
through the strand guide into the mould at the onset of casting,
in a long transportation path for the starter bar and thus a
long set-up time prior to the onset of casting, or, on the other
hand, if the starter bar is lifted from the run-out roller table
by a lifting means and is threaded into the mould from above, in
a complex design for an arrangement for supplying the starter bar
into the mould. If it were desired to remove the starter bar
from the strand guide already in front of the strand-guide part
that comprises a cutting means, when using a permanent head, for
instance by means of a rocker etc. reaching into the strand guide,
one would be forced to stop casting when the permanent head
welds, or gets clamped, with the initial crop portion of the
cast strand, since otherwise the cast strand would have to
follow the starter bar onto the rocker.
The invention aims at avoiding these disadvantages and
difficulties and has as its object to provide an arrangement
of the initially defined kind, which allows for observing a
short set-up time at the onset of casting and in which the means
for guiding the starter bar to the mould can be designed in as
little complex a manner as possible, wherein, however, a stoppage
of casting is avoided even if the permanent head cannot be sepa-
-- 2 --
3l~748~3
rated from the cast strand, and also in that case running on
separate paths from the separation site is possible for the cast
strand and the starter bar.
This object is achieved according to the invention in an
arrangement of the initially described kind by the combination
of the following characteristic features:
- the separating means is provided in front of the strand guide
part comprising the cutting means,
- the lifting means is arranged also in front of the strand guide
part comprising the cutting means, at a short distance behind
the separating means, i.e. at a distance that is shorter than
the length of the starter bar, and
- as the connection between the permanent head and the remaining
starter bar, a hook-shaped coupling that is open towards the
upper side of the starter bar is provided.
In case a welding or clamping of the permanent head with
the cast strand occurs, the starter bar is separated from the
permanent head by detaching the hook-shaped coupling; the starter
bar is then further conveyed out of the strand guide along the
path provided therefor; the permanent head remains on the cast
strand and is conveyed with the same via the strand-guide part
comprising the cutting means. It is removed from the cast strand
together with the initial crop portion of the cast strand.
It is possible with the arrangement according to the in-
vention to arrange the separating means behind a final driving
roller, seen in the extraction direction of the strand, a particu-
larly early separation of the starter bar from the cast strand
thus being feasible.
Although it is known from German patent No. 1,210,140
to remove the starter bar from the cast strand out of the strand
'74~Z~l
guide at this site by means of a rocker that is pivotable into
the strand guide, yet the utilization of a permanent head is
not possible in the plant described in this patent specification.
The starter bar head always remains on the cast strand, forming
an undetachable part with the same. The starter bar head is con-
nected with the remaining starter bar by means of a claw-like
connection, which is disconnected when separating the starter
bar from the cast strand. If it were desired to use a permanent
head with this known plant, it would be necessary, as mentioned
farther above, to stop casting in case the permanent head does
not separate from the cast strand, since the cast strand cannot
follow the starter bar, which is already on the rocker.
Suitably, a pair of driving rollers arranged above the
strand guide as well as a starter bar guide branching off the
strand guide, designed as a rocker-like shunt and leading to the
driving roller pair, are provided as lifting means.
According to a preferred embodiment, the rocker-like shunt
is designed in two parts, one part being hinged so as to be
pivotable at the approximately horizontal strand guide and one
part being hinged so as to be pivotable above this strand guide,
and wherein the part that is arranged above the horizontally
arranged strand guide is pivotable beyond the vertical from a
position in alignment with the part arranged in the strand ~uide.
It is, however, also possible to provide the arrangement
according to the invention in a plant similar to that of
Canadian patent No. 1,071,830. Such a plant is provided with
a transporting car comprising a sliding or roller path, by which
the starter bar is transportable to an introduction part of the
strand guide, the transporting car carrying a conveying means
for the starter bar and the sliding or roller path having arcuate
-
z9
end parts, and wherein, furthermore, the lifting means for grip-
ping and lifting the starter bar is provided on the transporting
car. ]:n such a plant, the transporting car is displaceable, ac-
cording to the invention, only from a thread-in position at the
mould as far as to an accommodation position in front of the
cutting means (seen in the extraction direction of the strand)
and back.
Also with a plant similar to that described in Canadian
patent No. 1,075,873 and comprising a horizontal sliding or roll-
er path for introducing the starter bar, the sliding or rollerpath including arcuately designed front and rear end parts and
a displacement means movable along the sliding or roller path,
an arrangement according to the invention may be provided, the
sliding or roller path reaching from the mould as far as to in
front of the cutting means (seen in the extraction direction of
the strand).
According to a preferred embodiment, the hook-shaped COUp~
comprises a pin flattened on two opposite sides and a bore ac-
commodating the pin as well as a slot for letting through the
flattened pin, which slot extends from the bore and is open
towards the upper side of the starter bar.
The invention will now be explained by way of three embodi-
ments and with reference to the accompanying drawings, wherein:
Figs. 1, 3 and 4 are overall views of continuous casting
plants, in a schematic illustration, according to one embodiment
each; and
Fig. 2 illustrates a detail of Fig. 1, i.e. the hook-shaped
coupling, in section and on an enlarged scale.
In Fig. 1, a continuous casting mould 1 of a continuous
casting plant for slabs downwardly is followed by a strand guide.
-- 5 --
:~P~ 2~
The liquid steel flows from a tundish 2, via a casting tube 3,
into the cavity of the mould. In the bending zone 4 of the
strancl guide the cast strand 5 is bent from the vertical into a
circu]ar arc. Following upon the bending zone 4, a circularly-
arc-shaped strand guide part, the guiding structure 6, is pro-
vided, in which the strand is supported on its upper and lower
sides by supporting rollers 7, like in the bending zone 4. Sub-
sequent to the circularly-arc-shaped guiding structure 6, a
straightening zone 8 is provided, in which the circularly-arc-
shaped cast strand 5 is straightened. Then follows an approxi-
mately horizontally directed strand-guide part 9, in which the
strand is also still supported on its upper and lower sides by
means of supporting rollers 7. Subsequent to this strand-guide
part, a final pair of driving rollers 10 is provided. (Both in
the circularly-arc-shaped guiding structure and in the straight-
ening zone and in the approximately horizontally directed strand
guide part driving rollers also may be provided). The final
driving roller pair 10 is followed by an approximately horizontal
strand-guide part 11, which comprises a separating means 12 for
separating the starter bar 13 from the cast strand 5. After this
strand guide part 11, a further strand guide part 14, arranged
also approximately horizontal, is provided, which comprises a
cutting means 15 for cutting the cast strand 5 into lengths and
for separating the initial crop portion and the crop end of the
cast strand 5. This cutting means is designed as a torch cutter
17 movable on rails 16. In the following this strand guide part
]4 is termed torch-cutting roller table. After the torch-cutting
roller table 14 the run-out roller table (not illustrated) common
in continuous casting plants follows, from which the slabs cut
off the cast strand are lifted by means of a crane or the like.
7~Z9
The separating means 12 comprises a roller 19 which is lift-
able and lowerable by means of a pressure medium cylinder 18,
and by means of which the starter bar 13 can be lifted as soon
as the permanent head 20 of the starter bar 13 has passed the
final driving roller pair 10. The permanent head 20 denotes a
starter bar head that is permanently re-usable and has a recess,
e.g. a dovetail-shaped groove 21, which is filled with liquid
steel at the onset of casting, so that a direct casting connec-
tion forms with the cast strand 5 which, however, is detachable
by a relative movement between the permanent head and the cast
strand transversely to the longitudinal axis 22. The surfaces
of the permanent head 20 participating in this casting connec-
tion are prepared in a known manner in order to prevent a weld-
ing with the cast strand 5. By lifting the starter bar in the
region of its head-side end into the position illustrated in
dot-and-dash lines in Fig. 1, the dovetail-shaped-groove 21 of
the permanent head will slide off the dovetail-shaped cast-on
piece of the cast strand 5. The permanent head 20 is connected
with the subsequent link body 23 of the starter bar, which is
comprised of link bodies 23, 24, by means of a hook-shaped
coupling 25 that is open towards the upper side of the starter
bar, which coupling is illustrated in detail in Fig. 2.
As can be seen from Fig. 2, a pin 26 connecting the perma-
nent head 20 with the subsequently arranged link body 23 is
designed to be flattened on two opposite sides 27, 27'. From
the bore 28 provided in the permanent head 20 for accommodating
this pin 26, a slot 30 extends, which is open towards the upper
side 29 of the starter bar 13 and whose width 31 is by a slight
measure greater than the thickness 32 of the flattened part of
the pin 26, so that the pin, which is rotationally fast with the
32~
link body 23, can slide out of the permanent head 20 by pivoting
the link body 23 following upon the permanent head by about 90
into 1:he position illustrated in Fig. 2 and by movement in the
direction of the arrow 33.
A lifting means for the starter bar comprises a two-part,
circularly-arc-shaped, rocker-like shunt 34, one part 35 being
articulately mounted on the strand guide part 11 and one part
36 being articulately mounted above this strand guide part. Each
of these parts can be pivoted by means of separate pressure
medium cylinders 37, 38 from positions A and B, respectively,
illustrated in Fig. 1 in dot-and-dash lines, into positions A'
and B', respectively, illustrated in Fig. 1 in full lines, in
which the facing ends of these two shunt parts 35, 36 are in
alignment with each other. Above the shunt part 36 hinged above
the strand guide part 11, a driving roller pair 39 is provided
for the starter bar 13, by which the starter bar, once gripped
by it, can be conveyed upwardly, where it is taken up for
instance by a crane or where it reaches a deposit.
The lifting means taking the starter bar off the strand
guide part 11, which is comprised of a shunt 34 and the driving
roller pair 39, is arranged behind the separating means 12 at
a distance which is smaller than the length of the starter bar,
so that the starter bar has already been seized by the lifting
means when its permanent head reaches the separating means.
The arrangement functions in the following manner:
Already before the starter bar 13 has reached the separating
means 12 with its foot part 40, the shunt parts 35, 36 are
pivoted into the position drawn in full lines in Fig. 1, so
that the foot part 40 of the starter bar slides over these
shunt parts until it is seized by the driving rollers 41 of the
-- 8 --
~7~82g
driving roller pair 39. After the permanent head 20 has been
separated from the cast strand by lifting the roller l9, the
starter bar 13 is conveyed upwardly at a speed that is higher
than t:he conveying speed of the cast strand 5, the pivotable
roller 19 is lowered again by being pivoted back, and the cast
strand S reaches the torch-cutting roller table 14, where at
first the initial crop portion is separated and the cast strand
is divided into slabs of a predetermined length.
In case the permanent head 20 cannot be separated from the
cast strand 5, which may occur e.g. due to a poor preparation
of the permanent head or by clamping, the rocker-shaped shunt
parts 35, 36 are pivoted back from the positions A', ~' illus-
trated in Fig. 1 by full lines, into the positions A, B illus-
trated in dot-and-dash lines, the cast strand beiny further con-
veyed out until it has reached the position represented in Fig.l
in broken lines. In this position, the permanent head 20 still
is in alignment with the cast strand; the remaining part of the
starter bar is directed approximately vertically upwardly. It is
held by the driving roller pair 39. In this position the hook-
shaped coupling illustrated in Fig. 2 in detail, between the
permanent head and the link body 23 of the starter bar following
upon this head, can be detached by moving the starter bar up-
wardly in the direction of the arrow 33, whereupon the cast
strand 5 is further conveyed out until the initial crop portion
can be separated by the-torch cutter 17 on the torch-cutting
roller table 14. It is thus not necessary to stop casting in
such an emergency situation, although the starter bar 13 and the
cast strand 5 are conveyed out on separate paths from a point
(at 12) that lies in front of the cutting means 15.
By the arrangement illustrated in Fig. l, the starter bar
~741329
13 can also be threaded into the strand guide. The driving
rollers 41 of the driving roller pair 39 are then driven in the
reverse direction until at least the permanent head has been
seize~, by the final driving roller pair 10 of the strand guide
part 9, whereupon the starter bar is moved through the strand
guide as far as to the mould 1.
With the embodiment illustrated in Fig. 3, the continuous
casting plant is designed in substantially the same manner as
that of Fig. l; corresponding parts are denoted by the same
reference numerals. There is a difference in the lifting means
lifting the starter bar 13 off the strand guide 11. The lifting
means 42 according to Fig. 3 comprises a stationary guide 43
fastened to the structure 44 of the plant. In this guide a hook
46 fastened to a beam 45 is vertically guided, the hook being
liftable by a lifting mechanism 48 by means of lifting ropes 47
or lifting chains. On the casting platform 49 a transporting car
51 is guided on rails 50, being movable to the mould 1 from the
rear accommodating position drawn in full lines into the thread-
ing-in position drawn in broken lines. On the transporting car
51 a sliding or roller path 52 is arranged whose front end 53
and rear end 54 are designed in a quarter-circularly-arc-shaped
manner. Along the sliding or roller path 52 a displacement means
55 is movable to and fro in the longitudinal direction of the
transporting car. In the example illustrated, the displacement
means is designed as a car guided by means of wheels 56 on
rails 57 of the transporting car 51. The displacement means 55
contains a vertical guide 58 which registers with the stationary
guide 43. Furthermore, a carrying means 59 is provided on the
displacement means 55, comprising a manually or mechanically
liftable and lowerable peg 60.
-- 10 --
~L~74~ 9
In Fig. 3 the starter bar is illustrated as emerging from
the last driving roller pair 10. The foot part 40 just reaches
as far. as to the hook 46 of the lifting means 42. In this
position the lifting mechanism 48 of the displacement means
being in the rear position is actuated and the starter bar 13,
which is comprised of individual link bodies 23, 24, is lifted.
As soon as the permanent head 20 has left the final driving
roller pair 10, the liftable and lowerable roller lg is lifted,
the starter bar 13 thus being separated from the cast strand 5.
The starter bar is then lifted until the hook 46 is pulled into
the guide 58 of the displacement means 55. The displacement
means is now moved to the mould 1 in the longitudinal direction
of the transporting car 51, the starter bar being laid over the
~uarter-circularly-arc-shaped rear end 54 of the sliding or
roller path 52 and pulled over the horizontal part of this path.
Then the hook is hooked out of the foot part 40 of the starter
bar 13 and the transporting car 51 is moved as far as to the
mould until it has reached the position illustrated in Fig. 3
in broken lines. The displacement means 55 subse~uently moves
back into the rear position. The peg 60 of the carrier means 59
is inserted in a recess near the permanent head 20 of the starter
bar and the displacement means 55 is moved to the front end of
the transporting car 51 and the foot end of the starter bar is
threaded into the mould 1 via the front end 53 of the roller
path 52 until the foot part 40 of the starter bar 13 has reached
the first of the driven rollers of the strand guide, denoted by
61, and is held by the same. (This is illustrated in Fig. 3 in
broken lines). After decoupling the peg 60, the starter bar is
pulled into the mould until its head closes the bottom of the
mould. After the removal of the transporting car 51, casting may
1~7~8Z9
be started.
According to a modified embodiment, the mould and, if
desired, also a strand guide part, can be removed, the starter
bar being threaded into the strand guide and pulled in.
:[f a separation of the permanent head from the cast strand
were not possible, e.g. due to a welding of the cast strand with
the permanent head, the starter bar is brought into a position
(as with the embodiment according to Fig. 1) in which the
permanent head 20 is still in a horizontal alignment with the
cast strand, but the remaining part of the starter bar is direct-
ed at a right angle thereto, whereupon the hook-shaped coupling
25 of the permanent head 20 with the succeeding link body 23 of
the starter bar is detached by lifting the starter bar in the
direction of the arrow 33. The plant illustrated in Fig. 3 re-
veals a far less complex design of the means for conveying the
starter bar 13 to the mould than would be necessary for a plant
in which the starter bar is removed from the strand guide only
after the torch-cutting roller table 14.
In Fig. 4, a plant resembling that of Fig. 3 is illustrated,
wherein, however, the starter bar 13, after having been lifted by
means of the lifting device 62, is conveyed to the mould not by
means of a transporting car, but by means of a sliding or roller
path 63. A displacement means 64 for displacing the starter bar
along the sliding or roller path is designed in a manner similar
to the displacement means 55 illustrated in Fig. 3. The rails 57
provided for it are arranged stationarily above the casting
platform 49. The sliding or roller path for the starter bar
leading to the mould comprises quarter-circularly-arc-shaped
end parts 65, 66, wherein the quarter-circularly-arc-shaped
end part 65 that is arranged near the mould is hinged to the
- 12 -
74B29
structure 44 of the plant by means of two guide rods 67, 68 and
is pivotable by means of a pressure medium cylinder 69 from the
position drawn in full lines in Fig. 4 into the position repre-
sented in dot-and-dash lines. The funtioning of this plant is
similar to that of the plant illustrated in Fig. 3. (The thread-
ing in of the starter bar into the strand guide through the
mould is illustrated in broken lines.) However, contrary to the
plant illustrated in Fig. 3, no transporting car 51 is moved
when conveying the starter bar to the mould.
It can clearly be seen also from the embodiment according
to Fig. 4 that the means for conveying the starter bar to the
mould can be designed in a far less complex manner than with a
plant in which the starter bar is lifted from the strand guide
only after the torch-cutting roller table.
