Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is concerned with a means
for transverse cutting of a web of cellular plastic fed
continuously out of a forming machine, which means includes
a stand-mounted reciprocating carriage moving in synchronism
with the web in one direction of traverse and at the same
time dividing the web into separate lengths by means of
cutting devices.
The cellular plastic web consists of porous
plastic formed by sintering granules or grains expanded with p
a blowing agent. Forming machines of the type used for
forming in this instance are kncwn e.g. from Swedish Letter of
Patent No. 171,095. With continuously operating cellular
plastic forming machines it has been the practice for many
years to use so-called flying crosscuts equipped with saw
blades to cut the continuously moving web into the required ~`
lengths. The cellular plastic forming machines first used,
which had a comparatively low production rate of approxi-
mately 6 m per minute, interacted with crosscuts based on
the principle of a transverse saw blade which was mounted ~:
on and moved with a reciprocating carriage, cut the cellular
plastic web as the carriage travelled in one direction, and
then returned to its starting point.
However, with the further development of cellular
plastic forming machines to achieve a production rate
approaching 16 to 17 m per minute with a web width of 1.0 m,
the problems of meeting length tolerances with the flying
crosscuts increased.
The latest generation of cellular plastic forming
machines are capable of a web feed rate of approximately 27 m
~O per minute. This has meant an equivalent increase in the
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demands made on the flying crosscut, but despite very ;'
extensive development work the previously used conventional
flying crosscut has unfortunately proved unable to meet
these increased demands. This is easily understood if we
reflect that the cutter is required to work under difficult
conditions. Given a web traverse o 27 m per minute, a
cutting length of 1.0 m, a web width of 1.25 m and a length
tolerance of ~ 2 mm, the crosscut has to carry out 27 cuts
per minute, including return to a fixed starting point after ?
each cut, direct acceleration from O to ~7 m per minute by
the supporting carriage for each cutting operation, and a
transverse motion by the saw blade across ~he 1.25 m wide
web in a time of not more than 0.8 seconds, starting from
stationary condition.
Under these condition~ it has proved both in
theory and in practice impos~ible to do the work using
earlier known cutting means.
The purpose of the invention, in view of the above,
is to achieve a transverse cutting means which is capable
~0 of working a~ intended under the initially given conditions.
This i9 made possible by a means of the type described in
the introductory paragraph, to be characteri~ed especially
by the fact that the cutting dev1ces consist of mutually
spaced filamants extending transversely across the carriage
and capable of simultaneou~ motion perpendicular to the
plane of ~he carriage. It i8 further advantageous for the
filaments to be arranged so as to cut alternately towards
and away from the plane of the carriage during successive
synchronized traverses by the carriaye in the direction of
the web motion. When cutting the wob into leng~hs of
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approximately 1 m it has proved especially satisfactory to
use ~Ireé or more filaments, which then move parallel to
each other in the manner described above.
The invention is described in more detail below
in the form of an embodiment presented as an example and
with reference to the ac~ompanying drawing.
Figure 1 shows a side elevation of a cutter t'
mounted on a stand and designed in accordance with the
principles of the invention, to be used in combination
with a cellular plastic forming machine; Certain details
are cut away to better illustrate the inaividual components
of the cutter.
Figure 2 show6 a plan o the cutter illustrated in
Figure 1. '
The cutter illustrated in the drawing includes a ;~
reciprocating carriage 12 mounted on a stand 10, the carriage
being e~uipped with threa cutting devices 14 in the form of i~
mutually spaced ~ilaments stretched transversely across the
carriage 12 and capable of moving parallel to each other
and perpendicular to the plane of the carriage. The cel-
lular plastic forming machlne is not shown but is imagined ::
as being loca~ed to the right o the cutter, and the cel- '
lular plastic web 16 therefore moves from right to left in
the figures. The stand 10 comprises a supporting frame
constructed of transverse and longitudinal beams, 18 and
20 respectively, supported on four legs 22. The carriage
12 is mounted to slide on two separate guide shaft~ 24
attached to the frame, and the drawing shows two sliding
mountings 26 attached to the undersidP of the carriage 12
; 30 and each gripping one of th~ guide shafts 24 to allow
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sliding motion by the carriage 12 with respect to the ,~;
shafts. The carriage 12 is driven by a driving cylinder 28 ~;
which is coupled directly to the unaerside o the carriage.
The part of the carriage 12 designed to support the cellular
plastic web 16 comprises a number of parallel supporting ;~
rollers 30 located transversely across the carriage 12. In
addition, a number of pressure rollers 32 press upon the
top side of the web 16, their height above the supporting
rollers 30 being adjust~ble depending on the thickness of the
web 16. For this purpose the ends of the pressure roller~
32 can be fixed by means of locking devices 34 in relation
to brackets 36 projecting up from ~he ~ides of the base 38
of the carriage 12. Journals 40 at the ends of the rollers
pass through elongated ver~ical slots 42 in the brackets~
The three cutting 11aments 14, which have elec-
tric supply (not shown in detail), extend transversely
across the carriag~ 12 with their end~ cnnnected to busbar~
44 located along the side edges of the carriage 12 and
parallel to its direction of traverse. It is an advantage
if the po~ition o~ the ends of the filaments 14 can be
altered relative to the busbars 44 to obtain the de~ired
~pacing between the filament~ 14. The illustrated embodi-
ment has two cylinders 46, one located approximately at the
middle of each of the supporting bars 48 to enable vertical
movement of the busbars 44 and hence at the same time of the
filaments 1~. The compressed-air driven cylinders 46 and
the supporting bars 48 are naturally well insulated elec- ~;
trically from the busbar~ 44. The cylinders 46 are also
oil stabilized and supplied with fluid from two separate
tanks 50. Using an arrangement of this type the filaments
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14 can be kept in motion throughout the cutting operation
at a constant speed suited to the density o the cellular !~
plastic web 16. ,
A damping cylinder 52 i5 provided ~:o damp the
deceleration of the carriage 12 on its return (towards the
right of the drawing), to prevent excessively abrupt
stopping which might damage the e~uipment.
The cellular plastic web 16 is fed into the
carriage 12 via driving belt~ from the cellular plastic
forming machine and fed of~ the carriage 12, after cutting,
onto slide bars 56. Forward movement of the web cuttings
on the slide bars 56 iq brought about by the pres~ure from
the cuttings behind.
To supply the starting pulse for the filament
cutter, a ~ea~uring whe~l ~not shown) in contact with the
continuously moving cellular plastic web 16 can be arranged
to generate in a manner known per se ~ia an electronic
length measuring instrum~nt a ~ignal which activates an
electromagnetic valve. The length measuring instrument ;
can be pre3et to the desired triggering length.
A holding device 60, actuated by a compressed-air
driven cylinder 58, i9 arranged so as to clamp the web 16
again~t an underlying counterpart 62 located on the carriage
12 upon a starting pulse baing received. The starting
pul-~e also cau~es acceleration of the carriage 12 immedlately
the web 16 is clamped by the holding device 60. During
this acceleration the cylinder 28 of the carriage 12 i~
subjected to more or les~ full air pre~sure; upon attain-
ment of the desired final speed, matching the speed of the
web 16, the cylinder 28 is ~ed via a ti~e-controlled switch
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valve (not shown~ at a controlled pressure corresponding to
the continued traverse of tha carriage 12. This arrangement
achieves a perfect balance between the carriage 12 and the
continuously moving cellular plastic web 16. Without this
co-ordination, the clamping ~f the web 1~ betwe~n the holding
device 60 and the underlying counterpar~ 62 can cause the
web 16 to be stretched, torn off, or slswed down. Slowing
or 3tretching of the web 16 can cause tolerance errors in
the length of the web cuttings. ~ ;
When carriage 12 traver~e is initiated, the fila~
m~nts 14 also start their vertical motion. In this course
of this motion, which t~ke~ place alternately upward~ and
downwards, the ~ilaments 14 cut completely through thq web
16. When cutting with the three ~ilaments 14 illu~trated,
two web cuttings of length exactly one meter and one cutting
of nominal length one meter are obtained. The length
tolerance obtained for the last-m~ntioned cutting is closely
bound up wlth the tims adju3tment of the holding device 60
and the carriage acceleration.
After the filamen~s 14 have cut the web 16 into
the desired lengths, a ~ensor (not shown) is activated, and
after a preset time lag, which can be altered depending on
the density of the web, the carriage 12 returns to its
starting positi~n, its motion being damped by the damping
cylinder 52 mentioned abovs. The tims lag is to allow the
filaments 14 to cut completely through the web 16 and to be
stretched before the return o~ tho carriage 12.
The next cutting cycle takes place in a manner
~nalogous to that describ3d above, with the difference that
this time the filaments 14 mcve in the opposite direckion
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with respect to the plane of the carriage as they cut
through the web 16.
SUPPLEME~TARY DISCLOSURE
The device described above allows only straight,
vertical sections to be cut in the cellular plastic web,
although the edge or pro~ile of the cut sides of the
cellular plastic panels produced by the above method must
commonly be given a different form allowing adjacent panels
to overlap each other, for example for insulation. In
this manner, considerably less heat is iost than if straight
cut panels are set side by side. In the past, the procedure -
for producing insulating panels with the flanged edges on
all sides in a continuous process has hitherto been ~low
and costly.
A second machine was provided with edge cutters
which cut the desired shaps o flange along the two trans-
verse sides of the panel. In this process, the direction o
feed of the panels must be changed several times by 90
befo~e the panel again reaches the original production line,
along which it is conveyed for further processing and/or
treatment.
It is de~irable to improve the cutter de~cribed
above so as to allow the desirsd profile to be cut in the
edge transversely across the directio~ of the web at the
same time as the web itself is cut. This permits the
production line to run in ~he ~ame direction at all points.
The panels, once cut, will not need to be diverted from the
linel and edge-cutters will therefore not be necessary.
In the drawings Figure 3 is a diagrammatic
section, ~een from the side, showing the structure of an
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arrangement whereby the filaments of a cutting davice, as
shown in Figure 1, may also be moved horizontally in ~le
plane of the carriage, and,
Figure 4 shows sections, ~en from the side, of
the edges of tiles in which various ,different: profiles have
been cut by means of the new cutting device.
The transverse cutter de~cribed above may be ~ r
modified with regard to certain components in accordance
with this invention, as illustrated in Figure 3. It should
be remarked that this arrangement is symmetrical and that a ,~
corresponding arrangement is naturally provided on the
opposite side of the cutter. In this version, cylinders 70 ;~
are mounted at approximately the middle of bars 72, providing
vertical motion relative to the direction of feed of the
cellular plastic web 16. Cylinders 70 and bars 72 aorres-
pond to cylinders 46 and bars 48 of ~igures 1 and 2.
~ supporting bar 74 to which the ends of the
filaments 14 are attached, r~ns parallel to each bar 72.
The supporting bars 74 are moveable in a horizontal direc
tion relative to the bar 72 by driving cylinders 76 located
above the supporting bars 74. Cylinders 76 may thus be
attached to the supporting bars 74 while the ends o the
corresponding piston rod~ are attached to the bars 72. The ~ '
direction ln which the supporting bars 74 are driven is
controlled by guides 78. Guiding devices 80 are also
provided to control the movement of the bars 72 in a
vertical direction~
The bars 72, moveable in a vertical direction
through the action of the cylinder~ 70 are so arranged that
at points on their vertical path they act on two stop lugs,
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82 and 84, one of the stop lugs 82 being provided for ::
ascending motion, the other 84 for descending motion. The :
stop lugs 82, 84, may be linked together - by a link 86 -
in such manner that when activated they respectively open
or close an electric switch, not shown in the dxawing,
providing pulses to start or stop the driving cylinder 76.
An adjusting lever ~8 is provided for adjustment
of the position of the lugs 82, 84, relative to each other
and to the cellular plastic web and so enables the desired
profile to be cut. It should, of course, be noted that the
bar 72 and the support bar 74 can be moved simultaneously
to allow diagonal cutting of the web.
The embodiment illustrated in Figure 3 shows,
naturally, only one version of the invention, which may be
modified within the limits of the claims.
Figure 4 shows various profiles which can be cut.
Having described what is believed to be the best
mode by which the invention may be performed, it will be
seen that the invention may be particularly defined as
followS:
~ ans for transver~e cutting of a web of cellular
plastic fed continuously out of a forming machine, said
mean~ including a stand-mounted recip.rocating carriage
moving in synchroni-~m with the web in one direction of tra-
verse and at the ~ame time dividing the web transversely
into separate lengths by means of cutting devices, and
wherein the cutting devices consist of mutually spaced
filaments extending transversely across the carriage and
capable of simultaneous mot~on perpendicular to the plane
of the carriage~
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The invention ~urther comprises means for trans-
verse cutting described above wherein the filaments are
arranged so as to cut alternately towards and away from the
plane of the carriage during successi~e synchronized
traverses by the carriage in the direction of the motion of
the web.
The invention further compri~es means for tr~ns-
verse cutting as described above, wherein the cutting
devices include three or more filaments which are capable
of moving parallel to eaah other.
The invention further comprises means for trans-
verse cutting as described above wherein the filaments are
so arranged as also to be capable of horizontal motion in
the plane o the carriage and allowing the c~tting of
profiles of other than ~tralght vertical section.
The invention urther comprises means for trans-
verse cutting as described above characterized in that the
driving cylinders are arranged so as to be controlled by
guiding devices according to the vertical position of ~he
filaments to the web.
The foregoing is a description of a preferred
embodiment o~ the invention which i~ given here by way of
example only. The invention is not to be taken as limited
to any o~ the specific ~eatures as described, but compre-
hends all such variations thereo~ as come within the scope
of the appended claims.
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