CA2066582A1 - Method and apparatus for stabilizing the run of a paper web or the like during diagonal cutting - Google Patents
Method and apparatus for stabilizing the run of a paper web or the like during diagonal cuttingInfo
- Publication number
- CA2066582A1 CA2066582A1 CA002066582A CA2066582A CA2066582A1 CA 2066582 A1 CA2066582 A1 CA 2066582A1 CA 002066582 A CA002066582 A CA 002066582A CA 2066582 A CA2066582 A CA 2066582A CA 2066582 A1 CA2066582 A1 CA 2066582A1
- Authority
- CA
- Canada
- Prior art keywords
- web
- flow
- carrier surface
- cutting
- gaseous medium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000005520 cutting process Methods 0.000 title claims abstract description 51
- 238000000034 method Methods 0.000 title claims description 16
- 230000000087 stabilizing effect Effects 0.000 title claims description 11
- 238000010276 construction Methods 0.000 claims description 10
- 239000011888 foil Substances 0.000 claims description 2
- 230000000712 assembly Effects 0.000 claims 1
- 238000000429 assembly Methods 0.000 claims 1
- 238000007493 shaping process Methods 0.000 claims 1
- 230000001419 dependent effect Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- KRTSDMXIXPKRQR-AATRIKPKSA-N monocrotophos Chemical compound CNC(=O)\C=C(/C)OP(=O)(OC)OC KRTSDMXIXPKRQR-AATRIKPKSA-N 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
- D21G3/00—Doctors
- D21G3/005—Doctor knifes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/04—Paper-break control devices
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
- D21G9/00—Other accessories for paper-making machines
- D21G9/0063—Devices for threading a web tail through a paper-making machine
Landscapes
- Paper (AREA)
- Replacement Of Web Rolls (AREA)
- Advancing Webs (AREA)
Abstract
Abstract During the diagonal cutting of a paper web, the tail (W1) for threading of the web (W) is cut out of the web and widened to a full-width web as the cutting member (1) travels in a direction transverse to the web at the free run of the paper web for example in the multi-cylinder dryer section. Associated with the cutting blade (1), there is a carrier surface (2), at the edge of which is a nozzle assembly (3), through which is provided a flow (VA/VB/VC/VD) of gaseous medium directed substantially away from the imagined centre point (2') of the carrier surface. The purpose of the flow is to stabilize the run of the web (W) at the cutting point (C). The carrier surface (2) operating in a reduced pressure owing to said adjustable flows is connected through one or several flow means (5) to a device such as a compressor that produces the gaseous medium, such as air.
Description
Method and apparatus for stabilizing the rtln of a paper web or the like during diagonal cutting.
The present invention relates to a method and apparatus for stabilizing the run of a paper we~ or the li~e during diagonal cutting wherein the tail for threading of the web or the like is cut out of the travelling paper web and widened as the cutting member travels in a dire~tion transverse to the web at the free.run of the web, for example in a ~ulti-~ylinder dryer section, the stabilizing being enhanced by a flow of gaseous medium effected by means of a carrier surface involved with a reduced pressure.
~5 ~or cutting the tail for threading of the web out of the paper web and for widening.this tail by means of a so-called diagonal draw i~..the...mul~i-cylinder dryer section o~ a paper machine or the like, use has been made previously of a method which attempts to stabilize the free run of the web in c~urse of cutting by using a counter-blade on the other side of the web.together with the cutting blade. ~his soluiion causes synch~o-nizing problems and complicity ~f the structure. One way of alleviating this problem has been that disclosed for example by Fin~ish Publication No. 6380C of an examined patent application showing a device on the cutting blade side of the web for creating, ~n air flow parallel to the web at the area of the blade~
~he air flow induces an incre~sed or reduced pressure at the cu~ting point for controlling the run of,the web. Because the guided air flow before the Ctltting member in the direction of travel of the web is parallel to the direction of travel of the- web, the force co~.ponents resulting therefrom influencing the we}) canllo be directe~ accurately and there~ore t'~e ~evi.ce does ~IOt ~ o~i.de a fu'ly controlla~l.¢ run o.`the ~el~ at: the Cll~ t-i'`'~ ~oint ' 2 ' 2066~82 Fin~lish I~atent Application No. ~30C~ proE~o~es a sti~bilizing member associated with the cutting blade as a new solution, the member heing preferably provided with a suction for effecting a flow from the ~eb towards said member. It cinnot be denied that t~is solution has been proved satisfactory in normal runs in the practice. However, under ~_ertain circumstances it has ~een found out that various device~ and tubings used in connection therewith may be p~rtly blocked due to the suction principle used in the above-men-tioned method. Hence, there exists a need for an alternative solution based on a blowing principle, ...
especially in view of such difficult circumstances.
The purpose of the invention is to provide an improve-ment as far as the above-mentioned drawbacks are concerned. For reaching this goal, the method according to the invention is mainly characterized in that the reduced pressure is created around the cutting member or at least in the area located before the cutting point, seen in the direction of travel of the web, by means of a flo~ of gaseous mediu~ directed substantial-ly awi~y from the carrier surface and,the cutting memhe~
at least during the cutting operation, said flow 2~ being ~enerated by means of a flow brought t~ the edge o~ the carrier surface. The device according to the inven~ion is characterized in that the device comprises a no,zle asse~bly at the edge of the carrier surface for effecting a flo~ of gaseous medium directed ,0 away from the carri,er surface and the cutting member ~ith the i~id of il flo~.~ hrough~ to the ed~e of the c:arrier surface ~lth the e~ict c- flo~J means.
~ i~r)~,iclt~ n(l oper~-~iic~.<] re li~bi~ltv owin~ to the '~: uti~izeci no7,zl~ }~icJ~ nc~ l~5 a~-eo' iOIl cdn ~e ~nt,ionec~
,~;t, ~-,r~ .c-.~ es ~I trlr rJr~ r~t ' ~ V G .~ t I ( ' rl, ~ 1 ' C;: ~tin~ .~.r~ -h~
to a compact, easily movable construction. sy means of the method and device according to the invention, the stabilizing of the paper wob can be initiated substantially as early as before the carrier s~rface and beforç th~ associatod cutting member becausr~ O~ ~
nozzle blow that is accomplished before the cu~ting point, as seen in the direction o~ travel of the web, and directed opposite to the direction of travel of the paper ~eb. In accordance with the invention, it is also poss~ble to ad~ust in each particular case the reduced pressure needed between the carrier surface and the paper web by adjusting the partial flows blown from the nozzle devices and/or by adjusting the total flow brought to the carrier surface, said reduced pre~sure being in the well-known ma~ner dependent on the speed, thickness and surface quality of the web, to mention some examples.
The gaseous medium is most preferably passed to a housing-like construction, wherefrom it is passed to the edges of the carrier surfa~e by suitably guiding it. The closed side o~ the housin~.construction facing the web can at the same time constitute the well-sealed carrier surface that makes the reduced pressure possible.
The invention is described in the following in more detail with reference to the accompanying drawing, wherein Fig. 1 shows the location of the apparatus according to the invention in a dryer section, 3~ ~i.g. 2 srho~ ; a cross-section of an advantageous embod~ment in accordance with the inven-tior" ;~nd Fig. ~ shows the embodime~t in accordance with the invention as seen in the direction of the web.
Figure 1 shows in side view a part of the rear section of the dryer section of a paper machine, formed by upper cy~inders 8 and lower cylinders 9. ~ web W
travels in the direction D over ~he cylinders 8 and 9 along a tortuous path, while i~ is supported by felts on the cylinde~s and has a free run hetween an upper cylinder 8 and a lower cylinder 9 (so-called~double guidance). The felts and the rolls guiding them are not shown herein. A horizontal trave~sing beam 10 situated perpendi~ularly to ~he direction of the travel of the web is mounted in the machine ~rame. The beam is equipped with a cutting apparatus f~r the web W, mounted movably in the longitudinal direction of the beam. The blade 1 Or the apparatus is pivotable into a cutting posi~ion where its e~ge cuts the~web W. The cutting apparatus is mounted on a carriage travellin~
in the longitudinal direction of the beam 10, and as the carriage moves forward and the blade has as~u~ed its cutting position, the web c~n be widened to a full-width web in the diagonal cutting.
2~ ' The above-mentioned carriage and the mounting of the apparatus according to the invention is not shown he~ein, because it comprises a simple construction not to be discussed in conjunction with this invention.
Figures 2 and 3 show one advantageous compact em~odi-ment of the device in accordance with the invention in schematic sectional and planar views, not showing, for instance, fi~ing means ~or mounting ~he device on the afore-mentioned carriage in more detail. The body of the device is constituted of a housing-like con-struction 11, in which is mounted a cutting blade 1 and into ~hich a flo~ of air is led through a chan-nel 5. The wall of the housing facing the web W formsthereby a carrier surface 2 with its outer surface, the carrier surface being situated around the cutting point c subst~ntially pa~allelly to ~he web. In the embodiment shown the cutting membe~ 1 is a rotating cutting bla~e, but it could be also a ~tationary Ohe.
The rotating moVemeht of the cutting blade can be accomplished in the known manner most preferably by means of a driving device driven either by p~essurized air or electricity.
In ~he Figure, the cutting, blade i~ shown in i~s cutting position ~here the rotating blade 1~, cuts the weh W with i~s.edge la at a point,de~oted by letter C
and separates the tail W1 for ~hread~ng fro~ the rest of the web W. ~he blade rotates' in a.,:p~ane perpendicular to the plane of the weh W in the..direc-tion A a~ainst the direction of tra~el of the, web. At the edges of the carrier :sur~ace 2..associated with the hlade or at least at the edge closest to the cutting edge in the direction of travel.of the,.web-or along a part thereof, there is a nozzle assembly 3, the purpose of which is to effect a reduced pressure in the space between the carrier surface 2 surrounding the blade and the web w/Wl travelling in this area in order to stabilize the run of-the web. The distance of the web to ~e cut from the blade can-~e stab~ 1iz2d to a desired value by controlling the nozzle flows which depend in a ~.nown ~anner on the pr,operties of the materlal to be cut and on the cir.cumstances. The nozzles 3 can be constituted of slits.-located on the housinq 11 at the edges of the carrier surface ,ubstantially in a parallel relationship with the plane of the web, that is, of so-called foil nozzles which arc so directed that a flow passed through them from thc housillg ll creates a fast flow of air which i s S~rl i.c c~ntly U!lifOrm over the direction of width.
2066~82 Also a suitably shaped row of holes having a similar ex~ension can be used for the same purpose.
The flows needed in the embodiment of Figs. 2 and 3 are created ~y leading ~n overall flow V of a gaseous medium su~h as air through one or several flow means 5 from for example a compressor or the like to the inside of the housin~-like constru~tion 11 situated at the carrier surf~ce 2. The overall f~ow is further divided most preferably into partial ~lows VA, VB, VC, and VD, for example, one for eaoh edge, preferab-ly for example by means of guiding means 4 formed in the b~ck part 2' of the c~rrier surface 2. The partial flows pass further through the noz21e assembly.3 and are dire~ted substantially away fro~ the imagined centre point of the carrier ~urface 2 and from.the blade l, extendihg almost parallelly with the plane of the web W. The air present in the space between the carrier surface 2 and the correspon~ing::~rea of the opposite travelling web W/W1, induced by the flows directed away, is sucked with ~hese flows, causin~ thus the establishment of the reduced pressure withi~ said space.
The partial flows VA, VB, VC, and VD are directed from the nozzles 3 situated at the edges of the carrier surface 2 against the direction of travel of the web (VA) starting from the nozzles 3 situated before the cutting point, in the direction of travel of the web (VC) starting from the nozzles 3 situated after the cutting point C, as well as transversely to the direction of travel of the web to both sides away from the cutting point C approximately beside the cutting point starting fro~ the nozzles 3 extending in the direction of travel of the web (VB and VD).
Th~e flow vR is of particular importance, because it prevents the entrance of t;~e air flow entrained with the web W into the space between the carrier surface 2 and the web W.
The magnitude of the negative pressure is in a known S manner dependent on the properties of the material to be cut and on the cutting oonditions. For controlling and/or closing the partial flows, control and closing means 6 are provided, pre~erably in a~s~ciation with the guiding means 4 and the nozzle asse~bly 3. In additio~, for ensuring the ~tability of the pr~cess, particularly in changing conditions, in the solution in accordance with the embodiment, it is advisable to place the ~orresponding closing and con~rol devi~es 7 also in association with the flow channel 5 feeding the overall flow V divided into separate nozzles. It is thereby possible to make sure that, if for example a part of the nozzle assembly is closed, the inadver-tent rise in the flow speed in the active nozzles is prevented by choking the overall flow. The control of the aforementioned control and closing actions can be integrated in a simple manner in the rest of the process automatics, for example by automatically determining the set values of the control and closing devices on basis of other initial values of the process, for example with the aid of a microprocessor, resulting in the simplest possible use of the device.
In practice, the cutting is performed by-~eans of a device which is prefera~ly connected by means of an automatically returnable arm mechanism to the carriage travelling along the traversing ~eam, by trans~erring said carriage during the cutting operat~on on the ~r~-,versing bea3~l to a desired point in the direction of ~iidth of the web, the operating devices 6 and 7 3 ~ being in association with the nozzle assembly 3 and optionally also those in association with the flow 3eans 5 are set to their set values which depend in the ':nO:!n mallner on ~he process conditions, then the device 2066~82 producing the overall flow, such as a compressor, is activated and the rotating function of the cutter blade 1 is started. After these actions, the device is placed with the help of said arm mechanism in contact with the web w for outting it, during which operation it widens the tail W1 for threading of the web to a full-width web while it moves in the trans-verse direction B. The arm mechanism of the device in accordance with the invehtion can be simple, for example a mechanism having two positions, because the controll3.blo ~on;:~lC f~ ~3 help to nGl~ v~ d r~ducetl pressure and a distance between the carrier surface 2 and the web ~ that are suitable ~or the conditions.
After the cutting operation, the overall flow and the rotation of the blade is stopped, whereafter the locking of the position of the arm mechanis~, which function is mo~t preferably auto~ated, will be released and the arm will automatically return to its rest position.
The invention is not restricted only to the embodiment shown hereinabove, b~t it can be modified within the scope of the inventional idea disclosed in the claims.
Hence, the nozzle assembly can be, for instance, con-s~ituted of one or several nozzle means known as suchwhich each are provided with independently controllable and closable flows through their respective flow means. Of course, as disclos~d hereinabove, the inve~tion is applicable in conjunction with a rotating cutting blade as well as a stationary one.
The present invention relates to a method and apparatus for stabilizing the run of a paper we~ or the li~e during diagonal cutting wherein the tail for threading of the web or the like is cut out of the travelling paper web and widened as the cutting member travels in a dire~tion transverse to the web at the free.run of the web, for example in a ~ulti-~ylinder dryer section, the stabilizing being enhanced by a flow of gaseous medium effected by means of a carrier surface involved with a reduced pressure.
~5 ~or cutting the tail for threading of the web out of the paper web and for widening.this tail by means of a so-called diagonal draw i~..the...mul~i-cylinder dryer section o~ a paper machine or the like, use has been made previously of a method which attempts to stabilize the free run of the web in c~urse of cutting by using a counter-blade on the other side of the web.together with the cutting blade. ~his soluiion causes synch~o-nizing problems and complicity ~f the structure. One way of alleviating this problem has been that disclosed for example by Fin~ish Publication No. 6380C of an examined patent application showing a device on the cutting blade side of the web for creating, ~n air flow parallel to the web at the area of the blade~
~he air flow induces an incre~sed or reduced pressure at the cu~ting point for controlling the run of,the web. Because the guided air flow before the Ctltting member in the direction of travel of the web is parallel to the direction of travel of the- web, the force co~.ponents resulting therefrom influencing the we}) canllo be directe~ accurately and there~ore t'~e ~evi.ce does ~IOt ~ o~i.de a fu'ly controlla~l.¢ run o.`the ~el~ at: the Cll~ t-i'`'~ ~oint ' 2 ' 2066~82 Fin~lish I~atent Application No. ~30C~ proE~o~es a sti~bilizing member associated with the cutting blade as a new solution, the member heing preferably provided with a suction for effecting a flow from the ~eb towards said member. It cinnot be denied that t~is solution has been proved satisfactory in normal runs in the practice. However, under ~_ertain circumstances it has ~een found out that various device~ and tubings used in connection therewith may be p~rtly blocked due to the suction principle used in the above-men-tioned method. Hence, there exists a need for an alternative solution based on a blowing principle, ...
especially in view of such difficult circumstances.
The purpose of the invention is to provide an improve-ment as far as the above-mentioned drawbacks are concerned. For reaching this goal, the method according to the invention is mainly characterized in that the reduced pressure is created around the cutting member or at least in the area located before the cutting point, seen in the direction of travel of the web, by means of a flo~ of gaseous mediu~ directed substantial-ly awi~y from the carrier surface and,the cutting memhe~
at least during the cutting operation, said flow 2~ being ~enerated by means of a flow brought t~ the edge o~ the carrier surface. The device according to the inven~ion is characterized in that the device comprises a no,zle asse~bly at the edge of the carrier surface for effecting a flo~ of gaseous medium directed ,0 away from the carri,er surface and the cutting member ~ith the i~id of il flo~.~ hrough~ to the ed~e of the c:arrier surface ~lth the e~ict c- flo~J means.
~ i~r)~,iclt~ n(l oper~-~iic~.<] re li~bi~ltv owin~ to the '~: uti~izeci no7,zl~ }~icJ~ nc~ l~5 a~-eo' iOIl cdn ~e ~nt,ionec~
,~;t, ~-,r~ .c-.~ es ~I trlr rJr~ r~t ' ~ V G .~ t I ( ' rl, ~ 1 ' C;: ~tin~ .~.r~ -h~
to a compact, easily movable construction. sy means of the method and device according to the invention, the stabilizing of the paper wob can be initiated substantially as early as before the carrier s~rface and beforç th~ associatod cutting member becausr~ O~ ~
nozzle blow that is accomplished before the cu~ting point, as seen in the direction o~ travel of the web, and directed opposite to the direction of travel of the paper ~eb. In accordance with the invention, it is also poss~ble to ad~ust in each particular case the reduced pressure needed between the carrier surface and the paper web by adjusting the partial flows blown from the nozzle devices and/or by adjusting the total flow brought to the carrier surface, said reduced pre~sure being in the well-known ma~ner dependent on the speed, thickness and surface quality of the web, to mention some examples.
The gaseous medium is most preferably passed to a housing-like construction, wherefrom it is passed to the edges of the carrier surfa~e by suitably guiding it. The closed side o~ the housin~.construction facing the web can at the same time constitute the well-sealed carrier surface that makes the reduced pressure possible.
The invention is described in the following in more detail with reference to the accompanying drawing, wherein Fig. 1 shows the location of the apparatus according to the invention in a dryer section, 3~ ~i.g. 2 srho~ ; a cross-section of an advantageous embod~ment in accordance with the inven-tior" ;~nd Fig. ~ shows the embodime~t in accordance with the invention as seen in the direction of the web.
Figure 1 shows in side view a part of the rear section of the dryer section of a paper machine, formed by upper cy~inders 8 and lower cylinders 9. ~ web W
travels in the direction D over ~he cylinders 8 and 9 along a tortuous path, while i~ is supported by felts on the cylinde~s and has a free run hetween an upper cylinder 8 and a lower cylinder 9 (so-called~double guidance). The felts and the rolls guiding them are not shown herein. A horizontal trave~sing beam 10 situated perpendi~ularly to ~he direction of the travel of the web is mounted in the machine ~rame. The beam is equipped with a cutting apparatus f~r the web W, mounted movably in the longitudinal direction of the beam. The blade 1 Or the apparatus is pivotable into a cutting posi~ion where its e~ge cuts the~web W. The cutting apparatus is mounted on a carriage travellin~
in the longitudinal direction of the beam 10, and as the carriage moves forward and the blade has as~u~ed its cutting position, the web c~n be widened to a full-width web in the diagonal cutting.
2~ ' The above-mentioned carriage and the mounting of the apparatus according to the invention is not shown he~ein, because it comprises a simple construction not to be discussed in conjunction with this invention.
Figures 2 and 3 show one advantageous compact em~odi-ment of the device in accordance with the invention in schematic sectional and planar views, not showing, for instance, fi~ing means ~or mounting ~he device on the afore-mentioned carriage in more detail. The body of the device is constituted of a housing-like con-struction 11, in which is mounted a cutting blade 1 and into ~hich a flo~ of air is led through a chan-nel 5. The wall of the housing facing the web W formsthereby a carrier surface 2 with its outer surface, the carrier surface being situated around the cutting point c subst~ntially pa~allelly to ~he web. In the embodiment shown the cutting membe~ 1 is a rotating cutting bla~e, but it could be also a ~tationary Ohe.
The rotating moVemeht of the cutting blade can be accomplished in the known manner most preferably by means of a driving device driven either by p~essurized air or electricity.
In ~he Figure, the cutting, blade i~ shown in i~s cutting position ~here the rotating blade 1~, cuts the weh W with i~s.edge la at a point,de~oted by letter C
and separates the tail W1 for ~hread~ng fro~ the rest of the web W. ~he blade rotates' in a.,:p~ane perpendicular to the plane of the weh W in the..direc-tion A a~ainst the direction of tra~el of the, web. At the edges of the carrier :sur~ace 2..associated with the hlade or at least at the edge closest to the cutting edge in the direction of travel.of the,.web-or along a part thereof, there is a nozzle assembly 3, the purpose of which is to effect a reduced pressure in the space between the carrier surface 2 surrounding the blade and the web w/Wl travelling in this area in order to stabilize the run of-the web. The distance of the web to ~e cut from the blade can-~e stab~ 1iz2d to a desired value by controlling the nozzle flows which depend in a ~.nown ~anner on the pr,operties of the materlal to be cut and on the cir.cumstances. The nozzles 3 can be constituted of slits.-located on the housinq 11 at the edges of the carrier surface ,ubstantially in a parallel relationship with the plane of the web, that is, of so-called foil nozzles which arc so directed that a flow passed through them from thc housillg ll creates a fast flow of air which i s S~rl i.c c~ntly U!lifOrm over the direction of width.
2066~82 Also a suitably shaped row of holes having a similar ex~ension can be used for the same purpose.
The flows needed in the embodiment of Figs. 2 and 3 are created ~y leading ~n overall flow V of a gaseous medium su~h as air through one or several flow means 5 from for example a compressor or the like to the inside of the housin~-like constru~tion 11 situated at the carrier surf~ce 2. The overall f~ow is further divided most preferably into partial ~lows VA, VB, VC, and VD, for example, one for eaoh edge, preferab-ly for example by means of guiding means 4 formed in the b~ck part 2' of the c~rrier surface 2. The partial flows pass further through the noz21e assembly.3 and are dire~ted substantially away fro~ the imagined centre point of the carrier ~urface 2 and from.the blade l, extendihg almost parallelly with the plane of the web W. The air present in the space between the carrier surface 2 and the correspon~ing::~rea of the opposite travelling web W/W1, induced by the flows directed away, is sucked with ~hese flows, causin~ thus the establishment of the reduced pressure withi~ said space.
The partial flows VA, VB, VC, and VD are directed from the nozzles 3 situated at the edges of the carrier surface 2 against the direction of travel of the web (VA) starting from the nozzles 3 situated before the cutting point, in the direction of travel of the web (VC) starting from the nozzles 3 situated after the cutting point C, as well as transversely to the direction of travel of the web to both sides away from the cutting point C approximately beside the cutting point starting fro~ the nozzles 3 extending in the direction of travel of the web (VB and VD).
Th~e flow vR is of particular importance, because it prevents the entrance of t;~e air flow entrained with the web W into the space between the carrier surface 2 and the web W.
The magnitude of the negative pressure is in a known S manner dependent on the properties of the material to be cut and on the cutting oonditions. For controlling and/or closing the partial flows, control and closing means 6 are provided, pre~erably in a~s~ciation with the guiding means 4 and the nozzle asse~bly 3. In additio~, for ensuring the ~tability of the pr~cess, particularly in changing conditions, in the solution in accordance with the embodiment, it is advisable to place the ~orresponding closing and con~rol devi~es 7 also in association with the flow channel 5 feeding the overall flow V divided into separate nozzles. It is thereby possible to make sure that, if for example a part of the nozzle assembly is closed, the inadver-tent rise in the flow speed in the active nozzles is prevented by choking the overall flow. The control of the aforementioned control and closing actions can be integrated in a simple manner in the rest of the process automatics, for example by automatically determining the set values of the control and closing devices on basis of other initial values of the process, for example with the aid of a microprocessor, resulting in the simplest possible use of the device.
In practice, the cutting is performed by-~eans of a device which is prefera~ly connected by means of an automatically returnable arm mechanism to the carriage travelling along the traversing ~eam, by trans~erring said carriage during the cutting operat~on on the ~r~-,versing bea3~l to a desired point in the direction of ~iidth of the web, the operating devices 6 and 7 3 ~ being in association with the nozzle assembly 3 and optionally also those in association with the flow 3eans 5 are set to their set values which depend in the ':nO:!n mallner on ~he process conditions, then the device 2066~82 producing the overall flow, such as a compressor, is activated and the rotating function of the cutter blade 1 is started. After these actions, the device is placed with the help of said arm mechanism in contact with the web w for outting it, during which operation it widens the tail W1 for threading of the web to a full-width web while it moves in the trans-verse direction B. The arm mechanism of the device in accordance with the invehtion can be simple, for example a mechanism having two positions, because the controll3.blo ~on;:~lC f~ ~3 help to nGl~ v~ d r~ducetl pressure and a distance between the carrier surface 2 and the web ~ that are suitable ~or the conditions.
After the cutting operation, the overall flow and the rotation of the blade is stopped, whereafter the locking of the position of the arm mechanis~, which function is mo~t preferably auto~ated, will be released and the arm will automatically return to its rest position.
The invention is not restricted only to the embodiment shown hereinabove, b~t it can be modified within the scope of the inventional idea disclosed in the claims.
Hence, the nozzle assembly can be, for instance, con-s~ituted of one or several nozzle means known as suchwhich each are provided with independently controllable and closable flows through their respective flow means. Of course, as disclos~d hereinabove, the inve~tion is applicable in conjunction with a rotating cutting blade as well as a stationary one.
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Method for stabilizing the run of a paper web (W) or the like during diagonal cutting, wherein the tail (W1) for threading of the web or the like is cut out of the travelling paper web (W) and widened as the cutting member (1) travels in a direction (B) transverse to the web at the free run of the web, for example in a multi-cylinder dryer section, the stabi-lizing being enhanced by a flow of gaseous medium effected by means of a carrier surface (2) involved with a reduced pressure and situated substantially parallelly to the plane of the web (W), c h a r a c-t e r i z e d in that the reduced pressure is created around the cutting member (1) known as such or at least in the area located before the cutting point (C), seen in the direction of travel of the web, by means of a flow (VA, VB, VC, VD) of a gaseous medium directed substantially away from the carrier surface (2) and the cutting member (1) at least during the cutting operation, said flow being generated by means of a flow (V) brought to the edge of the carrier surface (2).
2. Method as claimed in claim 1, c h a r a c t e r-i z e d in that the flow (VA, VB, VC, VD) of a gaseous medium directed away from the carrier sur-face (2) is blown substantially parallelly to the plane of the adjacent travelling web (W, W1) from a nozzle assembly (3) situated at the edge of the carrier surface (2) at a suitable speed (va, vb, vc, vd) in such a manner that a reduced pressure stabilizing. the run of the web is generated in the space between the carrier surface (2) and the web (W, W1) travelling at the corresponding location.
3. Method as claimed in Claim 1 or 2, c h a r a c-t e r i z e d in that the flow (V) of a gaseous medium is brought into a housing-like construction (11) associated with the carrier surface (2) using flow means (5), preferably along a common flow channel.
4. Method as claimed in Claim 3, c h a r a c t e r-i z e d in that the amount of the overall flow (v) entering the nozzle assembly (3) is adjusted and/or closed by means of an operating device (7) situated in the flow means (5).
5. Method as claimed in any of the preceding Claims, c h a r a c t e r i z e d in that the division of the overall flow (V) into partial flows (VA, VB, VC, VD) is adjusted by means of a guiding means (4) situated before the nozzle assembly (3).
6. Method as claimed in any of the preceding Claims, c h a r a c t e r i z e d in that the partial flows (VA, VB, VC, VD) blown through the nozzle means (3) located at separate edges of the carrier surface (2) are closed and/or their speeds (va, vb, vc, vd) are adjusted separately by means of controll-able operating means (6).
7. Apparatus for stabilizing the run of a paper web (W) or the like during diagonal cutting, wherein the tail (W1) for threading of the web is cut out of the travelling paper web (W) and widened as the cutting member (1) incorporated in the apparatus travels in a direction (B) transverse to the web, the apparatus being provided for effecting a flow of a gaseous medium stabilizing the web by means of a stabilizing carrier surface (2) involved with a reduced pressure and being associated with the cutting member, c h a r a c t e r i z e d in that at the edge of the carrier surface (2) there is a nozzle assembly (3) for effecting a flow (VA, VB, VC, VD) of gaseous medium, such as air, directed away from the carrier surface (2) and the cutting member (1) with the aid of a flow (V) brought to the edge of the carrier surface (2) with the aid of flow means (5).
8. Apparatus as claimed in claim 7, characterized in that it comprises a closed housing-like construction (11) associated with the carrier surface (2) and connected to flow means (5) for introducing the flow (V) thereto.
9. Apparatus as claimed in Claim 8, c h a r a c t e r-i z e d in that the nozzle assembly (3) is situated in one of the edges or in several edges of the housing like construction (11).
10. Apparatus as claimed in one of the preceding Claims 7 to 9, c h a r a c t e r i z e d in that said nozzle assembly (3) comprises a nozzle means known as such which is preferably a uniform slit nozzle that is, a so-called foil nozzle, or which consists of a row of holes.
11. Apparatus as claimed in Claim 7 or 8, characterized in that said flow means (5) that is connected to a device producing the gaseous medium, such as to a compressor, comprises an adjusting and closing valve (7).
12. Apparatus as claimed in Claim 8 or 9, c h a r a c t e r i z e d in that in the housing-like construction (11) are provided, preferably for instance by shaping the back-part (21) of the carrier surface (2), guiding means (4) for dividing the overall flow (V) into partial flows, and/or the construction is provided with adjusting and closing devices (6) for adjusting and closing the partial flows (VA, VB, VC, VD) emerging through the nozzle assemblies.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI903723 | 1990-07-25 | ||
| FI903723A FI84923C (en) | 1990-07-25 | 1990-07-25 | Method and apparatus for stabilizing the course of a paper web or the like in oblique cutting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2066582A1 true CA2066582A1 (en) | 1992-01-26 |
Family
ID=8530840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002066582A Abandoned CA2066582A1 (en) | 1990-07-25 | 1991-07-24 | Method and apparatus for stabilizing the run of a paper web or the like during diagonal cutting |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU8198191A (en) |
| CA (1) | CA2066582A1 (en) |
| DE (1) | DE4191689T (en) |
| FI (1) | FI84923C (en) |
| SE (1) | SE9200901L (en) |
| WO (1) | WO1992001835A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009056625B9 (en) * | 2009-12-02 | 2011-05-12 | Paprima Industries Inc., Dorval | Extension device for an air guide box |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI63800C (en) * | 1982-04-27 | 1983-08-10 | Valmet Oy | PROCEDURE FOR THE PURPOSE OF EXCHANGE OF SPECIFICATIONS IN THE PAPER |
-
1990
- 1990-07-25 FI FI903723A patent/FI84923C/en not_active IP Right Cessation
-
1991
- 1991-07-24 AU AU81981/91A patent/AU8198191A/en not_active Abandoned
- 1991-07-24 WO PCT/FI1991/000226 patent/WO1992001835A1/en active Application Filing
- 1991-07-24 DE DE19914191689 patent/DE4191689T/de not_active Withdrawn
- 1991-07-24 CA CA002066582A patent/CA2066582A1/en not_active Abandoned
-
1992
- 1992-03-24 SE SE9200901A patent/SE9200901L/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| FI84923C (en) | 1992-02-10 |
| DE4191689T (en) | 1992-08-27 |
| FI903723A (en) | 1991-10-31 |
| WO1992001835A1 (en) | 1992-02-06 |
| FI903723A0 (en) | 1990-07-25 |
| SE9200901D0 (en) | 1992-03-24 |
| FI84923B (en) | 1991-10-31 |
| SE9200901L (en) | 1992-03-24 |
| AU8198191A (en) | 1992-02-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |