Note: Descriptions are shown in the official language in which they were submitted.
Z63
This invention relates to an apparatus for heclt -treatmont o~
material to be worked on, SllCh as cast s~r.ips and billets, as well as ingots,
rods, tubes and tlle like, especially of aluminum or magnesium alloys The
heat treatment is of the general type in which the material is first pre-
heated and thereafter is held at a desired heat treatment temperature.
Cast strips, billets and extrusion and rolling products~ are
; customarily subjected to a heat treatment in order to homogenize, heterogenize,
or otherwise heat treat the material, For example, continuously cast billets
of aluminum alloys are first pre-heated after the casting, annealed at
temperatures between 500 and 620C, and thereafter cooled, During this ~.
treatment, the billets receive the structure desi.red for fur~her working, such ~ ~.
as for example by extrusion or rolling,
The material is customarily pre-heated with circulated hot gas, flue .
gas or with circulated hot air. As a result of the comparatively low
temperature of such a source of heat or "heater", the pre-heating step takes .
a very long time,
If the material is to be passed through the apparatus in a continuous
manner or in a flow operation, one normally tries to transport the material
~ at an equal and constant speed through the pre-heating zone and subsequently :i
through the holding heat treatment zone in the furnace. If the pre-heating
is of long duration, the pre-heating zone ~ust be disproportionately long with
respect to the holding zone or the material, upon entry into the holding zone,
, does not attain the proper annealing temperature, :
In using prior art apparatus, in order to achieve different annealing ~
' temperatures, the temperature of the hot gas in the pre-heating area or zone :
and in the holding phase area or zone must be finely controllable. This is
normally very difficult and a change in the temperature of the hot gas is ~-
usually only possible within narrow limits. Additionally, as was noted above,
in a flow-through operation, the material must normally be transported with
equal speed through the pre-heating zone and the holding zone
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~ s a result, ~he prior art apparatus has the disadvantage of
restricted flexibility in treatment of materials and, especially, a restricted
adaptability to the changing of conditions under which the material is treated.
An additional serious drawback in known devices is that during heat
treatment, ~hich eventually also comprises subsequent cooling, the material
suffers uneven deformations which may result in distortion or bending of the
' material.
One of the principal objects of the invention is to provide an
apparatuS of the kind referred to above but in which the noted drawbacks are
avoided and ~ith which apparatus a material of consistent quality can be
~ produced.
- Uniform quality may be ensured and deormation or distortion such
as bending, warping or curling of the billets may be controlled by the
individual treatment of the billetsO For this purpose it is particularly
advantageous if the billets are rotated about their longitudinal axes during
the holding. Such a rotation appears to be appropriate for avoidance of
warping or curving also during the cooling following the heat treatment.
The individual treatment of the pieces, i.e. the treatment of not
packed-type charges, but of long single billets, or of groups of shorter
series-arranged ingots, ensures a substantially uniform quality9 because the
individual billets, or ingots, are exposed to uniform pre-heating and heat-
maintaining conditions. The brief pre-heating period permits a better
balancing of the pre-heating and heat maintaining phase, The pre-heating
period for one billet made from an aluminum alloy to a final temperature of
from 500 to 600C requires from 10 to 30 minutes, dependent upon the cross-
section of the billet9 provided the pre-heating is carried out by means of
direct exposure to flames and/or hot gas radiation. The pre-heating of a
;~ billet in a separate pre-heating furnace permits an accurate individual
' temperature-control during the pre-heating process. This temperature controlJ
as well as the individual adjustability of the cycle sequences required by ;
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the pieces in the pre-heating Eurnace ancl the speed o passa~e o~ the billet
through the pre-11eating furnace~ p~r~it gr~at Elexibility of cycle frequcnce,
desirable to satisfy the requirements of post~treatment, of alloys requiring
different treatment, of interrupted operation, or of operation on partial
load.
In view of the high efficiency of the pre-heating furnace and of
its increased throughput, the ratio of investment costs and production
capacity of this prior system is relatively small, It permits a continuous
flow of pieces, In comparison with the conventional processes and systems~
these factors combined represent a substantial rationali~ing effect.
n A5 ~
It is ~ ~ of the present invention to modify the prior
system with regard to a further improvement in uniformity of quality of the
properties of the pieces and of the geometric form of the pieces as well as
of the economy of the process,
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This~Jbr36~ has been achieved by using a system of the aforestated
kind, in that the transporting means inside the holding or heat-maintaining
furnace is provided with memberspermitting the rotation of the individual
~i work piece about its longitudinal axis during its transportation, and the
cooling station is provided with means for a preferably continuous rotation
of the individual work piece during its cooling process,
According to the apparatus of the present invention, the required
manipulation of the work pieces has become reduced to a minimum.
The present invention comprises an apparatus for heat treatment `
of unfinished metal pieces comprising a pre-heating furnace, a first conveying
~1 means adapted to convey said metal pieces individually through said pre-
i heating furnace; a holding furnace; a second conveying means adapted to
convey said metal pieces individuallythrough said holding furnace and -
simultaneously to rotate said metal pieces along their longitudinal axes;
and a cooling station adapted to expose said metal pieces individually to a
cooling strec~m while said metal pieces are rotating along their longitudinal
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axes .
Ihe holding or heat-maintaining furnace is preferably adapted to
be heated either electrically, or by means of a fuel and offers a forced
circulation of the air in the furnace. The pre-heating furnace may be heated
in the same fashion, as long as it is ensured that the pre-heating temperature
of the heat carrier is higher than the heat-treatment temperature of the
material inside ~he heat-maintaining furnace.
~ccording to one advantageous embodimen~ of the pr~sent invention,
the transporting device is provided with stationary beams having Elat suraces
slightly declining in the direction of transportation of the pieces as well
as in the direction of lift with saw-tooth shaped projections on said flat
surfaces and, independent therefrom, lifting beams adapted to be driven in
; the direction of advance of the work pieces, said lifting beams being disposed
between and - in rest position - below the stationary beams and forming a
surface for receiving the work pieces. The lifting beams are provided with
successive prismatic abutments exceeding the diameter of the work pieces.
The work pieces are lifted from a depression formed by two neighbouring saw-
teeth by means of the lifting beams and lowered in controlled fashion onto
the declining surface of the subsequent depression, from where the pieces by
the force of their own weight roll into the bottom of the depression while
maintaining contact with the lifting beam which is being lowered in controlled
fashion opposite to the lifting direction,
For a fuller understanding of the nature and objects of the invention,
re~erence should be had to the following detailed description, taken in
connection with the accompanying drawings in which:
Figure 1 is a schematic view of an apparatus according to the
invention with two pre-heating furnaces and a successively arranged holding ;
or heat-treatment furnace;
Figure 2 is a cross-section through a pre-heating furnace which is
preferably employed in an apparatus according to the present invention;
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Figure 3 is a section along the lines III-III of Figure 2;
Figure 4 is a longitudillal section through a holding furnace which
can be emp.Loyed in the appara~us according to the .invention, with a transport
device constructed in accordance with the invention, ;
Figure 5 is a partial section according to lines V-V of Figure ~;
Figure 6a to 6e are transport phases succeeding one another in
time, in transporting the material through the heat retaining furnace; and
~ Figures 7 and 8 are, respectively, a partial longitudinal section,
- and a cross section according to line VIII-VIII of Figure 7, of a cooling
station at the outlet side of the heat retaining furnace.
.~ In the schematic plan view according to Figure 1, work pieces
comprising bars or billets are indicated by the reference numeral 1. From :
. a supply device or a magazine 2, the billets or bars 1 are automatically ;
transferred individually to a transport device 8, which can supply step-by-
step, in the direction of the horizontal arrows, into the pre-heating pre- ;: .
treatment furnaces 3 arranged to left and right of it, as seen in ~igure 1.
;` The billets or bars I are brought rapidly to full annealing temperature
individually in the pre-h ating pretreatment furnaces 3 in stationary
. condition by direct flame impingement by means of burners.
The individually heated ingots or billets are then discharged from
the pre-heating furnace 3 and are successively passed one by one from the
transporting device 8 to a heat-maintaining furnace ~, This furnace ~ is a
continuous flow furnace operated with circulated hot gas, for example hot ~.
air. The high annealing, cr maintaining tffmperature is kept constant within
. a narrow margin of tolerance across the length of the heat-maintaining
furnace so that in case the billet failed to reached the required temperature
during pre-heatingl it will attain its high annealing temperature in the
heat-maintaining furnace after a brief path of travel through the heat-
. maintaining furnace.
The pre-heating temperature can be adjusted finely and over a wide :;
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range, by alteration o the pre-heating time, that is of t~le period of time
in which -the billets 1 are held in thc preheating furnaces 3, an~ by control
of the burners, making it possible to obtain a uni~orm pre-h~ating of the
billets
The holding time in the holding or tr~a~men~ furnace ~ can be varied
according to the alloy composition of the billets and the desired structure
by alteration of the speed of through travel. The temperature in the holding
-~ furnzce 4 can be altered, for example by control of the temperature of the
hot air gas.
In the holding furnace 4 devices are provided for rotation of the
billets 1 about their longi~udinal axes, so that these are completely
uniformly heated and warping or curving cannot occur, and curved bars are
straightened.Th~bars,plas~icised by the annealing,automatically straighten
themselves by reason of their own weight. If the heat treatment does not
require a cooling step, and the holding or full annealing temperature is
suitable for further working, for instance for extrusion or rolling, the
billets emerging from the holding furnace ~ can be conveyed directly to a
further working device 5, for example, to an extrusion press or to a rolling
` mill.
In the case of where an adjustment of the temperature of the billets
is required prior to further working, the billets 1 are transferred from the
` exit of the heat retaining furnaces ~ to a cooling station 6I where they are
cooled individually with water and/or air At the cooling station 6 there
is arranged, as shown in detail in Figs. 5 and 6, a device for turning the
billets during cooling, to achieve a uniform cooling effect from all sides
and to prevent bending or distortion of the billets.
From the cooling station 6 the billets 1 reach a magazine 7, from
where they are conveyed to another station for further working.
The separation of the pre-heating and heat maintaining steps opens
the possibility of individually con~rolling the temperature, or transport
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spccd and seq~l~nce in the pre~heating and heat main~aining phase. This
leads to a very hi~h flexibility of the whole installation, brought about by
the optimal adaptability in each case to tlle different requirements during
operation, such as realization o~ dif~erent peak annealing tempera~ures,
desirable in practice for different alloys, interrupted operations, or
operation under part load and in adapting to successive devices or to stoppages
in the billet supply. A pre-heating or pre-treatment furnace operating by
direct flame impingement is smaller than other systems, resul~ing in reduced
space requirements of the installation. The material flow is greatly improved ~ -
and the quantity of the material flow is increased due to the continuous or
quasi-continuous performance. ~ -
Figs. 2 and 3 show a preferred preheating furnace in detail.
The pre-heating furnace has such a leng*h that a billet of the
largest size available in practice ~7-8m) fits into it lengthwise. In the
preheating furnace 3 there is a provided double strand or strip conveyor
chain 13 with carrier devices 12 mounted thereon to support the billets l.
The carrier devices 12 reach through a longitudinal slot into a cylindrical
furnace chamber 15 formed by two furnace shells 14. The furnace shells are
each journalled to swing by their lower ends on a carrier rail 16 and are ~;
held together above by spacing members 17, ~aterally, the furnace shells
are supported on the ~urnace wall by radial supporting bars 18, By removal
of the spacing members 17 and slight swinging inwards aro~md the supporting
points on the carrier rail 16, the furnace shells 14 can be dismantled
- without difficulty,
The furnace shells 14 have four radially directed rows of openings
22, into which discharge the nozzles 21, likewise radially directed, of pre-
mixed burners l9, 20, The radially directed rows of burners extend over the
entire length of the furnace shells 14, In doing so, the lower rows of -
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burners 20 are arranged close to the supporting devices 12 and directed
obliquely upwards, while the two upper rows of burners are offset by about 90
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~o thc corr~spon~:lng low~r rows of burners and directe~ obliquely downwards.
The upper rows o burllers 19 can bc acljusted with respect to the lower rows
of burners 20.
sy virtuc of the arrangement of the rows of burners 19, 20 during
heating of billets 1 or 1' (of smaller ~iameter), the surfac~s for heat
transfer are employed in an optimum manner, so that a circularly symmetrical
temperature distribution over the cross-section of the billets is achieved.
The output of burner nozzles 21 is individually adjustable so that the desired
temperature distribution is attained in each case at the end of ~he pre-
heating period.
The billets lie freely on the supporting means 12 throughout thepre-heating period so that ~he heat-produced lengthwise expansion of the
billets does not exert any undue horizontal orce on ~he conveyor chains 13.
The carrier devices 12 for the billets 1 or 1' have, at the place
where they penetrate into the slot formed between the two furnace shells 14,
a shaft which is rectangular in cross-section and which fills up the slot,
except for a safety spacing necessary for thermal expansion
The flue gases leave the furnace cavi~y 15 upwards through the
slot formed by the furnace shells 14 and the spacer members 17, and are,
together with fresh air, drawn away through a suction fan along the exhaust
duct 26. The outer casing 27 serves in this connection at the same time as
an air duct for the fresh air drawn in.
The pipes 28 necessary for the mixing and measuring of the
combustion gas, as well as a device 29 ~or measurement of the temperature of
bars 1 or 1', are arranged at the right-hand side of the furnace as seen in
Fig. 2.
For pre-heating, the billets are pushed into the furnace from the
transport device 8 and are taken over by the carrier devices 12 which are
moved by the double-run conveyor chain 13. The drive for the double-run
conveyor chain is controlled by a limit switch, not shown, which turns off
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the drive when a billet 1 runs against an abutment 30 at one end of the
furnace shells 1~
Measuring devices, not ShOWTI, arranged at uniform spacings over
the length of the urnace shells 14 measure the length of the billet inserted
at each moment. These measuring devices control the noz~les 21 in groups, so
; that at each moment only a number of nozzles corresponding to the length of
a billet is actuated for pre-heating. The burners are switched on when a
corresponding billet 1 has reached the position shown in Fig, 3 against the
abutment 30
With shorter billet lengths, it is also possible that the pre-
heating furnace 3 is supplied with a plurality of bars.
` The pre-heating furnace described above is also capable of
continuous operation, in which case billets are preheated in moving condition.
The drive is, however, preferably intermittent, so t~at the necessary matching
with the following period of annealing in the holding furnace 4 is achieved.
The holding furnace 4 shown in Figure 4 in longitudinal section is
constructed for continuous flow operation and is heated by hot gas. The hot
~ gas, for instancej hot air~ is blown by a radial-axial blower 40 against the
;` billets 1 or 1' which are to be kept hot, and is circulated in the furnace.
The billets lie in saw-tooth-shape depressions 42 with oblique
surfaces 42a formed on stationary beams 44 extending longitudinally through
the furnace space 43. The beams 44 are arranged with spaces inbetween, at
least two of which have a width x (Figure 5). Lifting beams 45 extend
intermediate and parallel to the beams 44. The lifting beams have flat
- surface portions 45' capable of receiving the billets 1 or 1'.
These flat surface portions 45' are defined and restricted by
prismatic abutments in the form of angle profiles 46 welded onto the flat
surfaces of the lifting beams. Adjacent angle profiles are spaced at
distances at least approximately equal to those of adjacent depressions 42
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3 ~ and have, relative to the~id~h ~f the flat surface portions 45/j (d~ e
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5~ k-rn~g~ , a small longitudinal expansion ~ when vi~wed in the direction A
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of travel of the billets 1 so that the bille~s 1, 1~ of conYentional cross-
section can roll off the flat surface portions 45' The angle profiles 46
merely form safety abutments, providing restraint in case the billets 1, 1'
should, for any reason, for example in lifted-up position, rotate, possibly
due to a torque acquired during the lifting.
Three lifting pipes 50, having a square cross-sec*ion, engage each
lifting beam 45 from below They are vertically moveable but non-rotatingly
held in rectangular longitudinal slots 51 in the floor 52 of the heat
maintaining furnace. One of these longitudinal slots 51 is shown for better
understanding in dot-and-dash lines in Figure 5, with floor 52 omitted.
One possible construction is shown at the right in Figure 4 Into
the lower end of each lifting pipe 50 there is welded a nut 53, through which
is passed a spindle 54, in screw-threaded engagement therewith, Each spindle
54 carries at its lower end a bevel pinion 55 which meshes with a bevel
pinion shifted by 90. All bevel pinions 56 are arranged on a common
horizontal shaft 57 which is actuatable by a drive mo~or 58 in order to
simultaneously raise the lifting pipes 50 and therewith the lifting beams 45.
The shaft 57 is journalled in housings 47, each associated with a
-~ 20 corresponding spindle 54, lifting pipe 50, and bevel pinion pair 55, 56.
The motor 58 and the housing 47 are mounted on a carriage 59 which operates
on rollers 60. This carriage is operated by a double-acting fluid cylinder
61 and is movable by a horizontal stroke y (shown in Fig. 6~c)~ which
corresponds approximately to the horizontal component of the length of the
oblique surfaces 42a~, The vertical travel z ~shown in Fig. 6(d~) of the
lifting beam 45 is produceable by the above described lifting arrangement
which is geared in such a manner that the lifting beams 45 with the angle
profiles 46 are adapted to be freely adjustable underneath the billets 1~
in their lowered positions and, in lifted-up position, the bill0ts 1, 1',
placed on the lif~ing beams 45, during horizontal transportationdo not run up ;~
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on the oblique surfaces 42a of the saw-t~othe~ depressions 42 of the
stationary beams 44. ;~
In a second preferred embodiment ~lllustrated in Figure 4 at th~
left hand spindle gear)> the nut 53 of each spindle gear 54 is movably held
in the housing 47 and tightly connected with the lower end of the lifting
pipe 50 and not turnable, but vertically movable in the housing 47 in the
axial direction. All component parts of the spindle gear are in this CQS0
lodged and mounted in the housing 47 and the lifting pipe 50 no longer
contains any movable parts of the drive gear This is advantageous for
mounting and maintenance
` The transport of the billets 1 by means of the transport device
shown in Figures 4 and 5 will now be described with reference to Figures 6a
to 6e.
The lifting beam 45, according to a preferred construction, is
; provided with prismatic abutments in the form of angle profiles 46 welded ,
,:
onto the flat surface 45' of the lifting beam 45, which serve merely to ensure
a minimal spacing of the bars 1 lying one next to the other, In the rest
position of the lifting beam 45 (Figures 4 and 6~, the flat surface portions
45' between the angle profiles 46 are slightly shifted ahead of the depressions
,
~ 20 420 In principle, the transport device would also function without the angle
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` profiles 46, that means with a lifting beam 45 having a horizontal flat
surface.
Figure 6a shows in the depression 42 a billet 1 of larger cross-
section with its CentTe offset against the direction o transportation A.
This is due to the incline of the oblique surface 42a which is smaller than
its denoted opposite surface.
In the rest position, according to Figure 6a the billets lie in the
depressions 42 of the stationary beams 44. The lifting beams 45 lie below `
the stationary beams. By actuation of the spindle gears~ the lifting beams
are moved upwards in lifting direction B. engaging the billets 1 and lifting
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~hese upwards ~roln tlle ~epressions ~2 through the distance z (L~igures 6~ .
After eompl~tion of this lifting movement, each lif~ing beam 45 is
movecl to the right as shown in Pigure Gc, by means of ~he drive cyl:inder 61,
through the distance y in transport direction ~. During this movement the
billets 1 move to above the oblique sur~ace ~2a of the next follow;ng
depressions ~2 in transport direction A. This ~nsures that also those billets
which were curved before exposure to heat treatment pass the holding furnace
wi-thout trouble,
After completed advance of the beam in the transport direction A,
the spindle gear is again actuated, bu~ now in direction s' which is opposite
to the lifting direction B, The speed of this movement is controlled in such
a way that the billets are gently lowered onto the oblique surfaces 42a of
the stationary beams (Figure 6d). The billets 1, due to their own weigh~J
now roll from the oblique surfaces 42a into the depressions ~2. During this,
they turn about an angle (Figure 6e~. However, this rolling movement is
controlled by the lowering movement of the lifting beam in the direction B',
that is to say it is braked to such an extent that no impact blow is created
on arrival in the depression 42 that would damage the shape and surface of
the billets which are annealed~ to plasticity,
The length and incline of the oblique surfaces 42a are such that
a sector of the billets turned through the angle reaches the depressions
42 and at each next following depression the billets arrive turned to
another sector, so that in each case another sector or portion of the billets
comes in contact with the circulated hot gas or the circulated hot air. Thus
the entire body of each billet may be maintained at a very uniform temperature. ~-
The rolling of the billets on the oblique surfaces 42a, controlled by the
downward movement of the lifting beam 45, leads to the automatic straightening ~ ;
of the billets due to their own weight, thus eliminating curvatures that
might have occurred for any reason.
In the manner described, the billets are transported through the
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heat treatment furnace, avoidin~ any gripping between the lifting beams ~5
an~ the stationary b~ams ~4, so tha~ the dange~ of injuring the ~illets is
practically eliminated,
Simultaneously with th~ lifting movement of the lifting bcam 45,
the furnace doors 48, 49, are opened for admitting or discharging the bars 1
or 1'. The furnace doors ~8, 49 are shown in Figure ~ in broken lines in
opened position.
In practice, the billets can attain weights of the order of 1 ton
T. Hence, according to the number of billets received at once in the furnace,
between 25 and 40 tons must be lifted, lowered and transported, in a ~,
controlled manner. This is not possible with a usual ~ombined drive, such
as an eccentric drive, and has been attainable for the first time by the
separation of lifting and transporting motion according to the invention,
The cooling station shown in Figures 7 and 8 has a spray chamber
70, on the upper wall 71 of which there is mounted an internal closed water
channel, comprising several segments 72 aligned in succession in the longitudinal
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direction. Each segment 72 of the water channel has a separate water supply
; pipe 73 and in its lower wall is provided with spray holes 74 which are
arranged close to one another in a row in ~he longitudinal direction of the
water channel. Below the water channel a shaft 75 a plurality of axles 76,
as well as a shaft 77 extend through the spray chamber, parallel to one
another. Shafts 75, 77 and axles 76 are all supported by bearing blocks
78; shafts 75, 77 and axles 76 being movable in journals 79, 80.
Shaft 75 is driven by a drive motor 81 arranged outside the spray
chamber 70 and carries a plurality of rolls 82 secured to it in a co-axial
relationship at regular intervals, Axles 76 are mounted to rock about shaft
77 by means of at least two rockers 8~. In the~normal position shown in
Figure 7, axles 76 lie in the same horizontal plane as shaft 75 and at a
distance from it adjusted to the size of the billets l and 1' to be handled,
which distance is smaller than the diameter of the billets.
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l~olls 83, w!l:ich are of the same diameter as the rolls 82 of the
shaft 75 are loosely nlounted on the axlc 76. Rolls 82, 83 are associated
in pairs, and form a prismatic reccss :for billets 1 or 1' Rockers 84
supporting axles 76 are rigidly connected to shaft 77 This shaft 77 is
shiftable by a pivoted cylindcr 85 and a crank arm 86 fixed to the shaft 77
and pivotally connected to a pist~n rod 87 of ~he cylinder 85. The rocker
84 is shown in rotated position in dot-and-dash lines
Thexe is furtllermore provided at least one transfer arm 88 to feed
the billets 1 into the spray device, This arm 88 is shiftable by a cylinder
89 with a piston rod 94, between the two positions shown in full and in dot-
and-dash lines, about the a~is of the shaft 75.
In the lower portion of the spray chamber 70 there is a collecting
tub or reservoir 90, from the deepest loca~ion of which there .issues a
discharge pipe 91 directed vertically downwards.
The spray device described operates as follows:
A hot billet 1 or 1' coming from the heat maintaining furnace is
set in motion along a roller conveyor 92 arranged alongside the spray device.
: The cyli.nder 89 has been actuated so that the transfer arm 88 lies below the
: track of the billet 1. When ~he conveyor 92 stops, the cylinder 89 is ..
extended, and hence the transfer arm 88 is lifted, raising the billet 1 -
; from the position shown in dot-dash lines, so that the billet may roll along
the flat surface 93 of the transfer arm 88, which is now slightly sloping
towards the rolls 82, 83 and the billet may thereby reach the prismatic
recess between the rolls 82, 83.
In order to prevent a hard drop of the billet into the prism formed
by rolls 82, 83 and possible damage to the billet, cylinder 85 is extended
simultaneously with cylinder 89, or remains extended from the preceding
operational phase. The rocker 84 is in lifted-up position, as denoted by
the dot-dash line in Fig. 8. In this position, roll 83 intercepts the billet
1, rolling down the transfer arm, without damaging the surface of the billet
'
2~3
Cylinder 85 is -then retracted so that roeker 8~, placed in a controlled
fashion in the lowered position - sho~n in drawn-out line - permits the billet
to be softly placed into the roll prism. Drlve motor 81 then begins to
rotate shaft 75 an~ thus rolls 82 (Figure 8) in clock-wise directionJ causing
the billet on the prism ~ormed by rolls 82, 83 to continuously rotate about
its longitudinal axis in counter-clock-wise direction. Rockers 8~, with
their axles 76 and rolls 83, are in their lower posi~ions, resiliently
supported by the column of air remaining in cylinder 85 even in its lowered
position. This ensures that any blowsJ possibly occurring during the
rotation of the billet, are yieldingly taken up and there is no danger of
- any surface damage, or distortion to a billet by any such blow. Water is
then sprayed through the spray holes 74 onto the billet 1 or 1', Since ~he
spray holes 74 are arranged over the whole length of the billet and at small
distances from one another, a very uniform cooling of the billet is achieved.
To discharge the cooled billet, piston rod 87 of cylinder 85 is extended,
.:
after previous retraction of piston rod 94 of cylinder 89 and consequent
shifting of transfer arm 88 into the lower positon shown in ull lines, so
that rockers 84 and axle 76 move from the full-line position into the dot-
dash-line position, This moves the billet out of the prismatic recess
between rolls 82J 83 onto the now outwardly sloping surface 93 of the
; transfer arm, from which it rolls down onto roller conveyor 92 for further
handling. Piston rod 94 of cylinder 89 is fully withdrawn and surface 93
of the transfer arm is placed in its lowered position as shown in Fig. 8 in
full lines.
Rotary brushes (not shown in the figures), adapted to engage the
surface of the work pieces, may be installed at suitable positions of the
apparatus of the present invention for surface treatment (by mechanical
scrubbing) of the work pieces.
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