Note: Descriptions are shown in the official language in which they were submitted.
2~81~a
l FIELD OF THE INVENTION
The invention relates to a method and apparatus for reducing a
transporting strain on elongated material passing through a treat-
ment chamber.
BACKG~OUND INFORMATION
,, ,
Elongated material in the present context may include ribbons,
tapes, band-~haped material, for example, made of textiles,
'-:. synthetic materials, or paper. The term also includes threads,
'~'ya''rns, ro'pe's,''strings~,''an'd the~ e. Such ~aterlals frequently
require a treatment in a treatment chamber. For this purpose,
:~ the elongated materials must be transported through the treatment
~ chamber pa~sing through an inlet lnto the chamber and through
.' an outlet out of the chamber. Inside the chamber or treatment
'. zone the surface of the elongated material pas~es along the sur-
face of at least one guide body whlch changes the travel direc-
tion of the elongated material through the treatment zone or
~ chamber. The material to be treated usually travel~ through
;.~;; the treatment zone along a meandering path, for example, for the
.. purpose of drylng or dyelng or lmpregnating or the like. The
~ 20 conventional dlrection changing guide body 18 usually a rotatably
. . .
.' mounted roller which 1~ either positively driven or it rotates
as a result of the contact of its surface with the material being
treated.
. .
~; In order to transport the material through the treatment chamber
or zone, it was nece~sary heretofore, to provide a posltive drive.
"~
:.
2 ~ 3
-~ 2
l Such positive drive may involve the driving of the guide rollers
and/or a further drive which pu119 the elongated material through
the treatment chamber or zone. In all conventional transport
drives of this type it is unavoidable that the elongated material
is subjected to a substantial transporting strain caused by
a longitudinally effected stress applied by the pulling force
of a take-up reel or the like. The direction reversing guide
rollers inside the treatment chamber are mounted in a fixed
position, except one such roller is mounted in a floating manner
to provide for some yielding, whereby the elongated material
is protected to some extent against too large tension stress.
: ..
Thus, when the take-up roller rotates too fast, the floating
roller travels out of lts orlglnal position into a posltion
in which the total length of elongated material within the treat-
ment zone or chamber i8 reduced. This movement direction of
. ~
~i the floating roller is maintained, for example, until a pre-
,A
determined threshold tensile stress is reached ln response to
`~ which, for example, an end switch or sen60r swltch provides
a signal for the control of the feed advance. Such a signal
.~ 20 may slow down the take-up speed or may increase the feed-in
:. . . speed. As a result, the floatlng roller again moves ln the
opposite dlrection untll a re~pective thre~hold value is sensed.
The feed advance 18 thus controlled to provlde for a back and
forth shuttling of the floating guide roller between presettable
limit values for the tensile stress applied to the material.
,
In spite of such a floating guide roller it is unavoidable,
that the type of material hereinvolved may be exposed to rela-
~i tively large tension stress during its transport through a
.~ .
.. ,................................... . ~ . .
~.. ' ' .. ~ :' - : "' ~ - :': ' . . ,
2~81~a
; 3
1 treatment zone or chamber. Thl6 i6 due to the fact that the
material being transported must take up at least that stress
that is necessary for moving the floating guide roller. To
this stress is added a stress component neces~ary for rotating
any guide rollers mounted in a ~tationary, but rotatable position. Even if
the stationarily mounted guide rollers are positively driven,
there may be synchronization errors that also re6ult in undesir-
able tensions on the elongated material. Even the friction
in the bearings of guide rollers that are rotating due to the
contact with the elongated material results in undesirable
tension stress which may differ from roller to roller and which
aaas up with the number of rollers. Exposing the elongated
material to such tension stress i6 undesirable because it ad-
versely influences the quality of the fini6hed elongated material.
This problem has not been solvea heretofore.
:, .
i OBJECTS OF TIIE INVENTION
~, In view of the foregoing it is the aim of the invention to
achieve the following objects 6ingly or in combination:
~:.
::
to reduce the above de~crlbed ten~ion ~tress to which
materials of the mentioned type are expo~ed in their treatment
; while still transporting the material uniformly and at the desired
speed through the treatment ~one or chambert
~ to transport the material by means of a blowing medium
;:.
which substantially reduces the appli~ation of tension stres6,
pos6ibly to the extent that at the take-up end of the elongated
J~ material a pulling mechani6m can be avoided:
~e
2a~sl~s
:
:
- to support the elongated medium on a transporting
-- cushion of flowing fluid; and
to provided a transport for the elongated material
with a minimum of stress independently of the fact that
the treatment may somewhat lengthen the material or that
the treatment may shorten the material, e.g. by
, stretching or shrinking.
.~
~ SUM~ARY OF THE INVENTION
:' 10
According to the present invention, there is provided a
method for reducing a transporting strain on elongated
flat material passing through a treatment chamber,
~ comprising the following steps:
J$ 1 5 ~ a) transporting said elongated material with a
transporting speed through said treatment chamber having
. an inlet and an outlet for said elongated material,
whereby a transport direction is from said inlet to said
outlet,
(b) guiding said elongated material at least around one
travel direction changing guide means defining a zone
. where a direction change begins between said inlet and
said outlet,
(c) forming a space of substantially triangular
cross-section bounded by a straight portion of said guide
means upstream, as viewed in said transport direction, of
said direction change zone, by a nozzle wall, and by said
elongated flat material, whereby said straight portion
merges, away from
said nozzle wall, into a curved portion of said guide
means where said direction change zone begins,
I
~3,.~ .
.~. . : : .
~s
4a 2~081
',
(d) introducing at least one flowing fluid jet through
said nozzle wall into said space of substantially
-triangular cross-section at least approximately in said
transport direction and substantially in parallel to said
straight guide means portion upstream of said direction
change zone of said travel direction changing guide means
as viewed in said travel direction, whereby a force
component extending radially to said travel direction
around said guide means is substantially reduced to
thereby reduce said strain, and
(e) imparting to said flowing fluid jet a flow speed
corresponding at least to said transporting speed for
transporting said elongated material through said
chamber.
The flowing medium generates a cushion at each location
where the travel direction of the elongated material is
changed. The cushion is produced between the surface of
a direction changing or direction reversing guide body
and the surface of the material facing the guide body
surface. Thus, the elongated material can float on such
a cushion and is transported by the flowing cushion
substantially free of friction. This type of transport
completely avoids the need for direction changing guide
rollers regardless whether they are of the driven or
undriven type. The direction reversing guide body may be
stationary and rigid but it must have a smooth surface of
the suitable curvature to
.~ ~
~ A
-
2 ~
1 achieve the direction change or reversal, whereby the radius
of curvature can be selected in a very wide range. Provided
s the direction reversal is performed several times in the treat-
ment zone or chamber, it i8 now also possible to avoid the above
mentioned floating roller.
., .
The above mentioned floating of the elongated material on the
cushion of flowing fluid which simultaneously transports the
elongated material, can be enhanced by additionally intxoducing
flowing fluid between the elongated material and an exit guide
plane, for example, in the form of a baffle plate, whereby again
the flowing fluid must have a suitable flowing speed. Due to
the low friction between the material and the flowing fluid
it i6 possible to even shrink the elongated material in the
;~ treatment chamber or zone without generating any tension stresg
in the elongated material ln the transport dlrection. Thus,
even where a shrinking takes place as part of the treatment
of the elongated materlal, a take-up roller downstream of the
f treatment zone or chamber is no longer necessary since the flowing
~ fluid performs the transport regardless whether the elongated
.,! 20 material is shrinking or even expanding. It 18 also no longer
necessary to correlate the lnput speed to the output speed.
Nevertheless, the transport is uniform and tenslon stress 18
avoided because the infeed and wlthdrawal of materlal no longer
depends on friction contact wlthln the treatment zone. ~8 much
material as necessary can be fed into the treatment zone or
chamber and a~ much material can be taken out as is necesgary.
If the feed-in speed should be reduced at the inlet end of the
i~ chamber, such reduction does not have any noticeable effect on
A
,,........ ~., ~ , ~ .
.. ,- .. , ,.. ~.. ~ .. . ..
.. , . . ,~.................... .. .
. - ~` . . . ....
.. . ~, . ;. ~ ., j . . . .
. ~.,, . , ..
. ........ . .
. .
2 0 ~
1 the quality of the elongated material because it does not affect
~,~ any tension stress within the material travelling through the
treatment zone or chamber.
By varying the density of the flowing fluid with due regard
to the density of the medium forming the environment in the
treatment chamber, it i8 posslble to influence the treatment.
The flowlng transport fluid and the treatment medium may both
be gaseous or both may be liquid or one may be gaseous and the
other liquid. The flowing fluid may contain additives for
the treatment of the elongated material. The flowing fluid
could be heated or it could be cooled, whereby again the desired
influence on the elongated material may be achieved.
,.,
Frequently, it is suitable that the flowing 1uid~ and the treat-
ment or environmental medium in the treatment zone, have substan-
, .
tially the same composition, whereby intermixing i~ of little
; concern and any need for any separation of components subsequent
, to the treatment is avoided.
~.'
.:~
~ Depending on the type of transport intended, it is po~ible
; according to the invention to apply dlfferent flowing speed~
`~` to the flowing tran~port fluld at the lndlvldual dlrection
,~ changing guide bodies. For example, the flowing speed may increase
`; from guide body to guide body. Different flowing fluids may
be used at different guide bodies and the density of the flowing
,~ Eluid may be different at different gulde bodies. These features
make it possible to take into account the characterietics of
,~:
~,~ the elongated material a~ they may change along the pass of
.,.~. .
~ the material through the treatment chamber or zone. For example,
..
..
7 2 ~ 5
1 if the elongated material should lenqthen as a re~ult of the
treatment, it is necessary to increase the transport speed
from the inlet of the treatment chamber toward the outlet of
the treatment chamber to properly transport the increasing
length of the elongated material. Similarly, lf the material
should shrink as a result of the treatment, it is possible
`' to reduce the transport speed from the inlet to the outlet.
!.'.
In all instances it i8 advantageous to avoid directlng the
flowing transport fluid in a direction radially to the length
of the materlal to thereby avoid any distortions in the material.
In the light of the foregoing it will be appreciated that the
, flow speed of the flowing transport fluid can influence the
~ transport speed of the elongated material. However, the trans-
,, port speed also depends on the surface characteristics of the
:i material and on the den~ity of the flowing transport fluld.
Normally, the transport speed of the elongated material will
be smaller than the flow speed of the flowing transport flula~
and the transport speed can be controlled without any problems.
Another advantage of the lnvention is seen ln that in addltion
~''$!' 20 to the transportlng by means of the flcwlng fluld,a conventlonal
tran~port may be comblned by means of a take-up roller outside
the treatment zone. Due to the reduced frictlon assured by
the cushionlng formed by the flowlng transport fluld, the
stress on the elongated material will be very small because
the pullinq forces generated by a take-up roller can be very
.~ small.
~,
'
::.;.
,;.
, ~
,:.,;:
... , ~ ~ ., .,. - ~ .
.::
: ;: . . .. , . i
; . . . .
2 ~
1 Depending on the characteristic~ of the elongated material it
may be advantageousto apply the flowlng transport fluid over the
entire width of the material. However, a denser elongated material,
such as paper web~, can be transported when the flowing transport
fluid i9 applied only to certain zones or even only along a
center strip or only along the outer eages. ~urther, it may
be aavantageous to distribute the flow speea over the width
of the elongated material 80 that, for example, a larger flowing
speed is applied along the edgefi while a smaller flowing speed 10 iS effective along the center of the elongated material or vice
versa. By applyingan increasea flowing speea along the edges it
~ is, for example, possible to reduce an escape of flowing tran~-
i port fluid away from the central zone of the elongated material,
whereby unaesirable force components that may be exerted by
the flowing transport fluid on the elongated material, are
either prevented or minimized. On the other hand, for certain
materials it may be desirable to have a higher flowing speed
for the flowlng transport fluid along a central zone than the
transport fluid speed along the edges. Such a speed distribu-
tion of the flowing transport fluid may be aesirable, for example,
for double ribbons having a central transport zone of a different
composition than the edges 80 that the transporting iB aacomplished
primarily by applying the flowing transport fluld to the central
strip while the lateral eages of the elongated material are
.~ merely æupported by the slower speed of the flowing transport
~ fluid, thereby preventing a slowihg down of the lateral edges
'~ of the elongated material relative to the central zone. The
~` flowing transport fluid may be applied in the form of a plurality
of individual jets having, for example, circular cro~s-sections
~ .
2~81~
. g
or any other suitable cross sections. Instead of a
plurality of individual jets, a broad flat jet may be
employed which has a width corresponding to the entire
width of the elongated material or which has several
zones distributed across the width of the elongated
material. Thus, it is possible to support the elongated
material along its entire width or along certain zones.
,.
According to the present invention, there is provided an
apparatus for reducing a transporting strain on elongated
flat material passing through a treatment operation in a
travel direction, comprising a treatment chamber for
treating said elongated material, said chamber having an
inlet and an outlet defining a transport direction from
said inlet to said outlet, means for transporting said
elongated material from said inlet to said outlet, said
transporting means including at least one material guide
means having a curved material guide surface for changing
the travel direction of said elongated material between
said inlet and said outlet, whereby said material guide
means define a direction change zone where a direction
change begins, æaid material guide means further having
a straight portion merging into said curved material
guide surface, and fluid flow means including a nozzle
wall upstream of said straight portion, as viewed in said
travel direction, said nozzle wall, said straight portion
and said flat material bounding a space of substantially
triangular cross-section tapering toward a point where
said guide means begin changing said travel direction in
said direction change zone for introducing substantially
in said travel direction at least one flowing fluid jet
~,,
... . ~, .. ,,. :
. i ..
`<s
2~81 ~
9a
into said space of substantially triangular cross-section
between said straight portion of said material guide
means and said elongated flat material, whereby a force
component extending radially of said curved material
guide surface is substantially reduced for reducing said
strain, said fluid flow means imparting to said flowing
fluid a flow speed corresponding at least to a
transporting speed of said elongated material.
The elongated material travels around the guide body for
the direction reversal. Each guide body is equipped with
at least one jet means for introducing a flowing
i transport fluid into a space between a surface of the
guide body and the elongated material. The flowing
; 15 transport fluid is introduced substantially in the travel
direction. The jet means impart to the flowing transport
fluid a flow speed which corresponds at least to the
transporting speed of the elongated material. The
flowing transport fluid may, for example, be compressed
air. The compressed air forms a moving support cushion
for the elongated material, thereby keeping the elongated
material substantially in a floating condition so that
~3 the latter may travel substantially free of friction
~ around the guide body while the flowing fluid transports
; 25 the elongated material. Thus, a substantial pulling
force does not have to be applied to the elongated
material, nor is it necessary that the elongated material
x entrains any guide rollers for rotating the guide
, rollers. By substantially reducing the friction and
hence the pulling forces on the elongated material, it is
possible to transport the elongated
:
:.:
.~ .
. .
2`~81~
1 material through its treatment zone or chamber substantially
without any distorting influences.
The jet means for introducing the flowing transport fluld compri~e
advantageously at least one nozzle which is arranged at a spacing
from the point where the change in the transport direction begins
to take place, whereby such spacing extends substantially in
- the transport direction upstream of said point. The nozzle is
80 directed that the flowing transport fluid i8 aimed tangentiallytoward
said point. The nozzle may, for example, be of the type capable
of producing a so-called flat section jet. Such jet has a flat
ribbon-type cross-section. However, other nozzle types may be
:~
used, for example, groups of nozzles may be arranged in a row
across the entire width of the elongated material to be transported.
One or 6everal nozzle groups may be arranged in this manner.
Preferably, each group is arranged along a straight line across
the width of the material. All nozzles in a row may produce
.,~ .
fluid jets all having the same cross-section or a different cross-
section, thereby generating transport jets having the same cross-
sectional flow area or different cross-sectional flow areas. In~ 20 the embodiment where several nozzles produce several different
jets, these jets may be produced by transport flulds under dif-
. . .
ferent pressures or by transport fluids having dlfferent densities
~i~ or other different characteristlcs. Nowever, depending on the
~;, type of material being transported and treated, it is quite pos-
~; sible to supply the ~ame transport fluid by a common source under
pressure to all nozzles. Where a common source of fluid under
pressure is used, the nozzles may be arranged in a ~ide wall
; of a tubular member having a rectangular or square cross-section,
....
.... .
:,, . , . - - ~ . . ..
~,$ ~ ~
... : . ................................ ~ : . .
' : ~`'` . ' .. :.. i- .
` 23~81~
11
1 whereby the nozzles are simply bores located in said side wall
close to a neighboring or adjacent wall forming part of the
guide body for changing the travel direction.
By using different types of nozzles and nozzle shapes and by
different nozzle arrangements it is possible according to the
invention to vary the influence of the flowing transport fluid
on the elongated material. The variation is accomplished by
properly selecting a desired nozzle configuration or nozzle shape
- and the respective fluid flow is then effective on the elongated
material during its transport through the treatment zone or chamber.
Thus, it is, for example, possible to tran6port a 6en8itive thin
elongated material, such a6 a fabric that is homogeneous in its
~ cros~-sectional structure, by a flat transport ~et without any
^~ problems, and without sub~tantially any distorting influences
of the flat jet stream on the seh~itive thin fabrlc. A quite
similar result is achieved by arranglng a plurality of nozzles
in the form of a row of bores, whereby the flat jet ~tream is
replaced by a plurality of small diameter individual ~et streams.
^~ The plurality of nozzles can simply be provided by the above
mentioned bore~ arranged in a side wall of a rectangular cross-
~ section or square cros~-~ection plpe resulting in a very 8imple
'~''t'.'~' structure.
, .,
,,:
`~ By applying the pressurlzed transport fluid in a controlled manner
to individual nozzles or to group~ of such nozzle~, it is also
possible to influence the effect of the flowing tran~port fluid
;~ on the elongated material. In this context it is po~sible to
;, vary individually or in combination the fluid pressure, the fluid
.:
~ .: :. . . ................................ .
. , . , :
- - . : . . -
2 ~
12
1 den~ity, the fluid composition, and/or the fluid temperature.
Thus, the influence on the transporting can be modlfied in a
multitude of ways to assure that the elongated material is sub-
stantially free of di~tortions while simultaneously using the
transporting fluid as a treatment medium, for example, for im-
pregnating or drying the elongated material. The present trans-
port and it~ multitude of control possibilities is equally appli-
cable to elongated material not having a homogeneous cross-sec-
tional structure. For example, fabric ribbons may be aenser
along their edges and less den~e in a central area between the
edges. Similarly, the density may change along the length of
~uch fabric ribbons. The present transport fluid can be con-
trolled to take into account these characterl~tics of elongated
material. For example, a rlbbon with denser or thicker marginal
zones will require a higher flowing speed along these denser
or thicker zones a~ compared to the flowing speea of the trans-
port fluid contacting a central zone of the ribbon. Thus, the
proper adjustment of the several flowing speeds wlth due regard
to the ribbon characteristics will assure that the marginal zones
will not be di~placed relative to a central zone 80 that again
~, the transport take~ place substantially without any distortion
of the ribbon being transported.
The guide body for changing or reversing the travel direction
of the elongated material is, for example, made o sheet metal
: which provides a simple and relatively inexpensive way of produc-
ing these guide boaies. The wall portion of the guide body where
; a direction change or reversal begins, must have a 6uitable spacing
''! from the outlet openings of the nozzle or nozzle~. Thus, the
i~.; ~, ' .
`:
.. ^ - . . .
- .
-: . ~ ;: - ..
- ' ~
2 ~ ~ 8 1 ~ 3
13
guide wall extends perpendicularly or at a3~all angle to a nozzle wall
of the guide body. The nozzle wall portlon reaches beyvnd the
guide wall portion so that the nozzles face in a direction approxi-
mately in parallel to the guide wall portion. Thu33, the flowing
transport fluid travels toward the point of direction change
substantially in a tangential direction. The arrangement is
such, that the guide-wall portion and the flowing fluid facing
surface of the elongated material form a wedge 6hape which in
itself also forms a type of nozzle into which the tran3sport fluid
is blown since the wedge shape nanxws toward the point of the directionchange.
For example, when elastic elongated materials for forming bandages
are to be transported, lt is deslrable to direct the transport
flow substantially in parallel to the guide wall portion of the
guide body at least at the point where a change in the travel
direction begins. This may be accomplished by changing the angle
between the guide wall portion and the nozzle portion of the
guide body from 90 to an angle smaller than 90 to provide for
, .,
~ a more rapid reductlon in the cross-sectional flow area in the
;~ nozzle channel formed by the wedge-shape, 80 that the channel
narrows quickly toward the point of dlrection change. In this
manner, the direction of the transport fluid and the direction
:.,.
o~ travel may sub~tantially correspond to each other. The radius
of curvature for a guide body wall portion intended for transporting
~ such flexible bandage material, may have a radius of curvature
'~j of about 10 mm. As a result, the entire apparatus can be rather
; compact, even though the guide body is requlred to provide a
complete direction reversal of 180. In such an lnstance the
guide ~urface portion will have a semi-circular cross-section.
... ~ '
., i
:, .
., ~ ,. . . - :
2 ~
14
1 ~ccording to the invention the nozzle or nozzles at each guide
body can be controlIed in accordance with the conditions pre-
vailing at the particular guide body. Thus, it i9, for example,
possible to provide a sensitive adaptation of the transport speed
to any shrinking or ~tretching of the elongated material at the
- particular gulde body within the treatment zone. For this pur-
'' pose, a speed sensor may be arranged just up~tream of the respec-
" tive guide body, as viewed in the transport direction, the respec-
-,. tive signal from the speed ~en~or ig then used by a central
proce~sing unit for controlling the flow speed of the transport
, fluid. On the other hand, all nozzles can be centrally controlled
", in uni~ff,~ rathër tha~'lndivid~ally.
,'~ BRIEF DESCRIPTION OF THE DRAWINGS
.~ .
In order that the invention may be, clearly under~tood, it will
now be described, by way of example, with reference to the ac-
companying drawings, wherein:
,
: .
~ Fig. 1 is a schematic sectional view through a treatment
,',, chamber equipped with a plurality of guide bodies,
,,' each of which i~ provided wlth lt~ transport
:.
' 20 nozzle~ for moving the elongated material through
...~
,,~ the treatment chamber,by a flùid flow~
.:,
... .
',f~ Fig. 2 is a sectional view, on an enlarged scale compared
~` to the illustration of Fig. 1, through a guide
i
body with its nozzle ~tructure, whereby the sec-
tion extenas approximately along ~ection line
II - II in Fig. 4, or section llne ~-~ in F~g. 5s
.
- . -
' ' ~' '` ~ ' '
,
2~81'j~
1 F~g. 2A ~hows a ~ectionAl ~lew ~imilAr to that of F~g. 2,
but lllu~trating a modlfied ~uide body wlth tran~-
port nozzle~ up~tr~am and downstream of the dlrec-
tlon changing zono ~f the gulde body~
Fi~, 3 i9 a ~eatLon~l vle~ similar to thAt of ~ig. 2,
however, ~howlng an ~nal~ned gulde leg of
the qulde bodyl
Fig. 4 is n sectlonal ~iew ~long seot~on line IV - IV
ln Fig. 2, or in Fig. 3J
. 10 F1g~J f8 d ~l~oti~ v~ 41m$1ar~~o~Chat of Fig. 4,
but ~howlng ~ comblnation of clrcular cro~s-~ea-
¦ tional nozsl~s with ~lot cro~-soctional nozzle
and
~ig. 6 lllu~trato~ w hQmAtlcally ~ ~low control ~ystem
for the supply of pre~urlzcd tranBpOrt fluid
to lndlvidual no~zles with the ~ld o~ a a~ntral
proce~-~ng ~nit.
~ DE~AI~ED DESCRIPSION OF P~E~ERRED EXAMPLE EMBODIM~NT~ AND OF
:, THE ~E6T MODE 0~ ~HE ~NVENTION
. ....................................................................... .
Flg. 1 lllu~trAt~ ~chematlaAlly A longltudl~l sectlon through
o. I,~ea~.u~e~ L 3~ ~I~c~ I L~ lelll- ;6V1101 2 W~ e
.; chamber. ~he chamb~r 33 has an lnlet 33a ~nd an o~tlet 33b for
the elong~ted materi~ uch 8~ a r~bbon or the llke. In~d~
the chamber 33 oppo~lte the inlet 33a there 1~ mounted A firBt
... .
,. 2~asl~
16
1 direction changlng 6tation 34 which imparts to the ribbon 1 a
directional change of about 90. The ribbon 1 travels through
the chamber 33 in the direction indicated by the arrows 8. Down-
stream of the guide station 34, as viewed in the travel direction
of the ribbon 1, there i~ a further guide station 35 imparting
to the ribbon 1 substantially a direction reversal of about 180.
The ribbon 1 then meanders back and forth horizontally in the
chamber 33 as guided by further guide stations 36, 37, and 38.
Although the inlet 33a and the outlet 33b are shown in Fig. 1
on the same side of the chamber 33, this construction is not
~, necessary for embodying the present teaching. Such an arrange-
ment may be convenient, but not absolutely necessary.
. . ,
The guiding of the ribbon 1 along a meandering path as shown
in Fig. 1, permits introducing into the treatment zone 2 a suf-
ficient quantity of ribbon for a uniform treatment while still
keeping the volume of the chamber 33 relatively compact. The
meandering also exposes the material to a relatively long path
within the treatment chamber 2, whereby the residence time within
the treatment zone 2 can be malntalned sufflclently long for
the desired treatment, even if the travel speed through the cham-
ber 33 is relatlvely high.
Guide plates 49, 50, 51, and 52 are mounted withln the chamber 33
for separating the treatment zone 2 into several sections. Con-
ventional speed ~ensors 39, 40, 41, and 42 are mounted wlthin
the chamber 33 in such positions that the speed of the rlbbon 1
can be measured. For this purpose, the ribbon 1 may, for example,
'
.
- . . :~ . . -
,. . . - :
2 ~ a
17
1 be provided with markers equally spaced along the length of the
ribbon and the sensors count the number of markers pa~sing per
unit of time, thereby providing a speed signal. In another speed
sensor, the ribbon may drive a wheel for generatlng a speed signal.
In any event, conductors 53, 54, 55, and 56 connect the respective
speed sensor to a central processing unit 48 shown in Fig. 6.
The CPU 48 processes the speed signals in accordance with a pro-
; gram stored in a memory 48a of the CPU 48 for producing control
impul~es to be supplied to control valves 43, 44, 45, 46, and 47
also shown in Fig. 6. These control valves are, for example,electromagnetically operated valvee connected through control
- conductors 57 to 61 to re6pective outputs of the CPU 48.
i
j Referring further to Fig. 6, the valves 43 to 47 are volume con-
trol valves connected through plpes 28 to 32 to the respective
~' guide station 34 to 38 shown in Fig. 1, or rather, to the tubular mem-ber 20 ofthe nozzle structure of the corresponding guide station.
The volume control valves 43 to 47 are further connected to a
manifold 62 which in turn is supplied with transport fluid under
pressure from a compressor 19 including a drive motor not shown.
The intake of the compressor 19 is connected to a noise muffler 63
if the transport fluid is a gas such as air.
., ~
~eferring to Figs. 2, 2A, and 3, each of the direction changing
stations 34 to 38 comprises a tubular member 20, for example,
having a rectangular cross-section and extending, for example,
across the chamber 33 from one side wall to the other opposite
side wall. The tubular member 20 has a first side wall 21 facing
in the travel direction prior to direction reversal and a rear
: . . ;. ~ , .
. , . :
2~1a81~
18
1 side wall 21a facing in the travel direction after direction
reversal. A pipe 30 is connected through the side wall 21a to
supply fluid under pressure into the chamber formed by the pipe 20.
llowever, fluid under pres~ure may be alternatively supplied through
an end wall a~ 6hown at 30'. The side wall 21 has an extension 21b
provided with a plurality of nozzle bores 15 and/or 16, please
ee Figs. 4 and S. These nozzles 15, 16 are distributed along
the entire width 9 of the elongated material 1 as seen in Fig. 5.
~; In Fig. 4 the nozzle~ 15 do not extend entirely to the very edges
of the material width 9. The arrangement in Fig. 4 i9 such that
no flowing tran6port fluid i8 ejected in zones 13. On the other
hand, in Fig. 5, the nozzle arrangement i8 such that elongated
flat nozzles 16 eject the transport fluid in zones 10 while the
circular cross-6ection nozzles 15 eject fluid in zones 12. In
the zones 12 no fluid i~ ejected along the spacings between neigh-
boring nozzle~ 15. The nozzles may be arranged in a row, preferably
a linear row, as shown in Fig. 4 or in two rows as shown in Fig. 5.
By changing the cross-sectional flow area and the configuration
of the cross-~ectional flow opening, it 18 possible to desirably
influence the flow pattern. The nozzle~ 15, 16 are located in
the extension 21b of the ~ide wall 21 of the tubularm ~ er 20 ~uqtnext
to a further side wall 22 of the tubular member 20.
A contact surface 21c for the elongated material 1 i~ formed
where the exten6ion 21b and the lower wall 22 of the tubular
member 20 meet. Thi~ contact surface 21c i~ al~o spaced from
the zone 18 where the direction change begins around the surface 3
of a curved portion 5 of the guide b~dy 4 having a ~horter leg 25
and a longer leg 25'. The tubular member 20 has a wall extension 27
,
2 ~ 5
- 19
1 extending away, preferably at a right angle, from the ~ide wall 21
of the tubular member 20. The exten~ion 27 prov~de~ a ~top and a
means for mounting the end of the shorter leg 25 to the tubular
member 20. The longer leg 25' rests on an upper wall 22a of the
tubular member 20, whereby the outwardly facing surface of the
leg 25' forms a guide surface7 for the material 1 and may extend
beyond the location of the tubular member 20 as shown in Fig. 1.
The leg 25' may, for example, be welded to the wall 22a of the
member 20. The legs 25, 25' and the curved portion 5 form a U-shape.
As described above, in the example embodiment the nozzles 15 and
16-receive-the pressurlzed-fluid-from-the interior of the tubular
member 20 which is connected to the respective supply pipe 28 to 32
shown in Fig. 6. Where the ~upply pipe~ 28 to 32 are connected
through the end walls as shown at 30', the outer chamber walls
must be sealed to the ends of the tubular member~ 20 or vice-versa.
Referring further to Fig~. 2, 2a, and 3, the individual guide
bodies 4 are preferably formed of sheet metal as the curved end
section of the gulde members 49 to 52. Preferably, the radius of
curvature of the curved portion 5 i~ a semi-circle having a radius
of, for example, 10 mm for a curvature of at lea~t 180. ~he
so formed guide body 4 is then connected, as mentloned above with
its leg 25 to the wall exten~ion 27 of the tubular member 20. Thus,
the outwardly facing surface 23 of the ~hort leg 25 and the elon-
gated material, form, or rather enclose, a wedge-shape into which
the fluid under pressure is blown through the nozzles 15, 16,
as indicated by the arrows 64. Due to the suction effect through
the nozzles 15, 16 there is a tendency of the elongated material 1
.,
,. . . .
2~8~
1 to be drawn against the contact surface 21c formed at the corner
between the wall extension 21b and the wall 22 of the tubular
member 20.
Fig. 2A show~ an embodiment similar to those shown in Figs. 2
and 3, however, in Fig. 2A additional nozzles 65 are arranged
in the upper right-hand corner of the tubular member 20, whereby
fluid under pressure as indicated by the arrows 65' ls blown
along the surface 66 of a gulde member 67 to further aid in
the transporting of the elongated material 1. The guide mem-
ber 67 is mounted with it~ left-hand end to a wall extension
27a in the same manner as was described above with reference
to the end o the leg 25 that is mounted to the wall extension 27.
Here again, due to the suction effect by the flowing fluid indi-
cated by the arrow 65' there i~ a tendency of the elongated
material 1 to contact a contact surface 21d of the tubular
member 20.
In Fig. 3 the short leg 25 of the gulde body 4 extends at a
small angle 26 relative to the wall extension 27 to modify
the wedge shape of the wedge space between the ~urface 23 and
the elongated material 1. The wedge shape is such, that the
widest opening into the wedge space is located ln a plane 14
defined by the outer surface of the wall 21 in the extension
21b of which the nozzles 15, 16 are located. The narrowest
section of the wedge space is located at the zone 18 where a
direction change begins. The spacing 17 between the plane 14
and the zone 18 should be such that the fluid flow 64 can extend
substantially tangentially to the surface of the guide body 4
2~81.~
21
; 1 at the point 18 where directlon change begins. If the spacing 17
- is too short, the fluid flow 64 will not coincide with the travel
direction or transport direction 8 in the inlet to the zone 18.
If the space 17 is too large, the ~peed of the fluid flow may
have become too ~mall for a proper feed advance of the elongated
material 1. Further, the spacing 17 should also not be 80 long
that an undesirable whirling of the fluld flow begins, causing
a lateral expansion of the flow fluid.
,~ i
In operation, the elongated material is first inserted into the~ 10 chamber 33. For this purpose a side wall, functioning as a
cover, i8 removed. Once the 1nsertion is completed 80 that the
elongated material 1 passes around each of the direction changing
stations 34 to 38, and the chamber i8 closed again, transport
fluid under pressure is introduced into the tubular members 24
passing through the nozzles 15 and 16 to travel in the direction
Z~ of the arrows 64. The fluid under pressure pushes itself between
the material 1 and the surface 3 of the curvea section 5 of the
guide body 4 at the point 8 where the direction change begins.
The fluid under pressure keeps lifting off the material 1 from
the surface 3 to form a travelling cushion between the surface 3
and the material 1. As a result, the material 1 18 entrained by
the fluid flow which thus transports the materlal 1 ln the direc-
tion 8 from the inlet side 6 to the outlet side formed
by the surface 7 of the guide body4. Such transport is substan-
tially free of friction.The number of direction changing stations
will depend on the dwell time needed for the particular treatment.
By varying the flow speed of the flowing transport fluid and/or
by varying the mass throughput of the flowing fluid through the
nozzles, it is possible to apply a transport spéed to the elongated
2 ~ S
22
1 material 1 with due regard to the characteristics of the material.
The influencing of the transport speed may be performed individually
at each direction changlng station. For this purpose the speed
sensors 39 to 42 are located in proper positions to sense the
speed of the material 1 at these positions and to produce respec-
tive control signals. Thu~, it is possible to take into account
any flexible stretching or any shrinking of the material at dif-
ferent points along the travelling path through the treatment
zone. If the material shrinks due to the treatment, more ma-
terial must be fed into the apparatus than will be carried outof the apparatus. The present control can be adju6td to such
an operating condition. Simllarly, if the, material stretches due
to the treatment, more material must be taken out of the chamber
than is being passed into the chamber. Here again, a very
individual adaptation of the feed advance i8 achieved according
to the invention so that undesirable tension 6tre6s is not applied
to the material 1.
In connection with the shrinking, it is, for example, known,
based on experience and experiments, how much shrinking will
2n take place. Thus, the required speed reduction in response
to the shrinking is a scalar amount that i~ known and the speed
can be controlled accordingly. The inlet speed can first be
adjusted at the guide station 34 by controlllng the valve 43.
The so established initial speed is then sensed by the sensor 39
to provide a signal on the conductor 53 to the central proces-
sing unit 48 which now knows the speed upstream of the station 34.
The further speed sensor 40 just downstream of the station 34
provides a further speed signal on the conductor 54 to the
- . ..: . - - ~ . . -
.. . :;, ~ ., , : . :,
- . .., :,. ...
23 2 0 ~
1 central processing unlt 48. Thus, it can be ascertained first
whether the station 34 indeed transports the material 1 in the
direction 8 and if the speed at 39 differs from the speed at 40,
a shrinking or stretching 1B recognized. AB a result, the
valve 43 can be controlled for providing the required adjust-
ment of the flow speeds in the statlon 34.
If no shrinking or lengthening or stretching is noted at the
inlet guide station 34, the speed measuring stations 41 and 42
still may provide further speed signals through the conductors
55 and 56 to the central processing unit to make ~ure that the
same transport speed prevalls at the respective direction chang-
ing stations to make sure that the quantity of material fed
into the chamber 33 is also removed from the chamber 33, thereby
providing an indication that no jamming takes place inside the
chamber. However, if a shrinking does take place, the sensors 41
and 42 provide respective slower speea signals and the speed
of the jet~ may be adjusted accordingly through the control
valves 44 to 47 as controlled by the central proces~ing unit 48
through the conauctors 58 to 61. Some or all of the guide sta-
`. 20 tions may be provided with their respective speed sensors up-. stream and/or aownstream of these stations 34 to 38.
,. . .
The central processing unit 48 shown in Fig. 6 has been des-
cribed so far as controlling the flow control valves for the
indiviaual stations 34 to 38. Nowever, the same control system
:~ can be applied to controlling individual nozzles at one guide
station. Thus, if the material 1 aoes not have a homogeneous
:. structure across its width, the individual nozzle holes lS, 16
.,, ~
2 0 ~
- 24
1 may be aonnected to indlvidual ~luld flow ~upply pip~ or hoee~
r~ther th~n to A aommon c,h~mber in ~ tubul~r memb~r 20 a~ d~cribed
above. ~hus, the ~u~d 10w can be lndlvldually And ~ensitively
eontrolled in ~ccordance wlth the rQqulrQment~ of Any particul~r
type o~ materi~l to b~ tran~ported. ~n ~ddltion to cont~olllng
the flow speed, it i8 po~lble ~o modlf~ the compo~itlon ~nd
denslty of the flowing tr~nsport ~luid in order to mlnlmlze any
di~tortlon of the mhteri~l to be treAted.
The preeent method ~nd apparatuq tran~port the type of mater~als
m~ntloned sub~ntlally fre~ of d~to~t~on~ bsaAu~e th~ tcn~on
I ~t.r~ e~ harQt~f~rQ h~ h~n mlnlm~ by the ~e-crlbed
~eature~ And bec~u~e the direction re~er~lng frl¢tlonal forces
~nd/~r dr~gglng forca~ ha~e been reduced to such ~m~ lu~
¦ that the~e force~ can now be di~regarded.
Although the ln~entlon ha- been de4crlbe~ with refer-nce to
speclftc ex~mple embodimente lt wlll be appr-ci~ted th~t it ~
~ Intended to aover all modifiaatlon~ and equl~ nt~ withln the
: ecope of the appended alalm~.
;~ - .
