US3096233A - Method and equipment for restoring paper paste web in paper making machinery and similar foils in other machines - Google Patents

Description

y 1963 M. RAPPAPORT ETAL 3 METHOD AND EQUIPMENT FOR RESTORING PAPER PASTE was IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 1 //VVE'/V7'0R.J

RAPPAPORI' RAPPAPORT SZUCHMAN l1 Mm B R W I z m m my w Q\ July 2, 1963 M. RAPPAPORT ETAL 3,096,233

METHOD AND EQUIPMENT FOR RESTORING PAPER PASTE WEB IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 2 IN l/EA/ T 021' H. RAPPAPOR'I' B. RAPPAPORT START B R. SZUCHMAN WW m M y 1963 M. RAPPAPORT ETAL 3,096,233

METHOD AND EQUIPMENT FOR RESTORING PAPER PASTE WEB IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet a I] J j 20 /NVEA/TOR! IJI Z M. RAPPAPOR'I' B. RAPPAPORT R. szucHMAN A y 1963 M. RAPPAPORT ETAL 3, 33

METHOD AND,EQUIPMENT FOR RESTORING PAPER PASTE WEB IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 4 a 1 a. J1 79' 197 6 3' j W/ T J 8 J wm/rom H. RAPPAPOR'I' 5 BY 2; 2$22 v July 2, 1963 M. RAPPAPORT ETAL 3,096,233

METHOD AND EQUIPMENT FOR RESTORING PAPER PASTE was IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 5 INVENTORJ H. RAPPAPORT B. RAPPAPOR'I R. SZUCHMAN Wm W y 1953 M. RAPPAPORT ETAL 3,096,233

METHOD AND EQUIPMENT FOR RESTORING PAPER PASTE WEB IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 6 M. RAPPAPORT By B. RAPPAPORT R. SZUCHMAN M. RAPPAPORT ET AL 3,096,233

July 2, 1963 METHOD AND EQUIPMENT FOR RESTORING PAPER PASTE WEB IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 7 3,096,233 ASTE WEB IN PAPER MILAR FOILS IN OTHER July 2, 1963 M. RAPPAPORT ETAL METHOD AND EQUIPMENT FOR RESTORING PAPER P MAKING MACHINERY AND SI MACHINES Filed March 26, 1957 9 Sheets-Sheet 8 July 2, 1963 M. RAPPAPORT ETAL 3, 3

METHOD AND EQUIPMENT FOR RESTORING PAPER PAsTE WEB IN PAPER MAKING MACHINERY AND SIMILAR FOILS IN OTHER MACHINES Filed March 26, 1957 9 Sheets-Sheet 9 a \QIQQ Q \N 7 WWW 2. A AMQ Q w //VVE/Vf0EJ' M. RAPPAPORT B. RAPPAPORI R. SZUCHMAN rzmtu 015.11 :08... dz... a 1 51.;

JON [-1200 rates This invention refers to a method of restoring running webs in foil manufacturing machines, such as cellophane or other plastic foil-like material, as well as running paper web in paper making machines, and furthermore this invention relates also to the equipment which enables to carry out this method.

The expression restoring is to be intterpreted in several senses, the first of which includes that instance when during the process of manufacturing a foil such as paper in known paper making machines, a break is detected in the running paper web, that the continuity of the Web is restored, so that there will be no interruption in the continuous feeding and delivery of the manufactured paper towards the dry end. The second meaning of the above quoted expression is that instance when the Web is torn across its entire Width, in any stage of its manufacturing process in the paper making machine or related stacks. As a consequence of the last mentioned definition, it will be seen that it is also possible to start automatically the manufacturing process With the equipment of the present invention.

By equipment is to be understood the combination of a number of apparatus, which combination is capable of performing one or several functions.

Although the invention will now be described with reference to the manufacture of paper, it will be apparent to those skilled in the art, that the principle of the method may be applied to other foil producing machines with suitable modifications in the equipment, for instance when reference is made to water ejecting nozzles as a type of cutting means for carrying out an incision in the paper paste web, upon the method applying say to cellophane manufacture, the cutting means will have to be of the blade type or of the electrode type. Since as such the adequate mechanical means for each art are known it is considered unnecessary to describe the method several times, once with regard to each art, but it will be suificient to refer to the paper manufacturing industry. Thus it being understood that reference to the Paper manufacturing industry only, has by no means a limiting character.

Since as such the paper manufacturing process is well known, it is not deemed necessary to enter into specific details tliereabout, and it will be sufficient to state that such a process consists in preparing a pulp slurry which is fed onto a crosswise vibrating endless wire fabric band, where in successive steps by drainage, vacuum suction and pressing or couch suction or the like, the pulp slurry is gradually transformed into a paper paste web of adequate cohesive quality, which is transferred from the Millspough suction couch to one or several couch suction press stacks and therefrom to drying stacks all of which have the purpose to gradually reduce the Water content of the web to thereby transform the latter into an endless paper foil.

It is known that wherever the paper Web is transferred from one stack to another or from one cylinder or roll to another, that there is a danger that a break starts either at one of the two edges or at an intermediate portion of the web. More particularly, the break starts where the web has to be separated from the first support Unite to pass to the next. Due to sticking properties of the torn portion of the Web on the cylinder and due to the tension to which the uninjured web is subjected, said break spreads towards the other edge, in the first case and towards one or both edges in the second case, thereby producing a complete cross rupture of the Web, so that the reeling stops and it is necessary to first manually refeed the paper web again through the different stacks towards the reeling end and second to avoid the accumulation of an enormous mass of paper at any intermediate stage principally at the portion where the rupture took place to prevent eventual damage to the machine.

Hitherto it Was-necessary to have human observers at least those portions of the machine where most of the breaks took place. It is therefore an aim to replace human observers by automatic restoring equipment.

Thus one concept on which the present invention is based is that wherever a break is detected in the Width of the paper Web, practically instantaneously at the height of the break line, a safety band is cut into the web at that edge portion which is opposite the initial break or tear, so that whilst said tear propagates, it cannot go further than the adjacent edge of said safety band. Thus, the safety band will always maintain the continuity of the web towards the bobbin end and thereafter there is time to gradually restore the total width of the paper web.

Also, the detecting and safety band cutting means can be automatically coupled with the width restoring means, whereby the entire arrangement becomes automatic.

In every paper making machine there is at least one portion Where the paper Web passes unsupported along a rather long path through the air. It may be that in those long air gaps the excessive tension to which that small safety band is then subject to may tear the same. Thus, in a further development of the above concepts, automatic pneumatic ejector means are located below the safety band portion which are able to automatically blow the new start of the safety hand back into the next stack.

Finally it will be apparent that the automatic pneumatic ejector means may be provided at any or all the beginnings of an air gap portion and always in the vicinity of the safety band section, so that the paper manufacturing process may be started automatically using the above described combination.

In addition similar automatic ejector means or other transport may be provided at the scrapers of the different press rolls, drier drums, et-c., to prevent an excessive accumulation of paper residue from falling back into the pertinent stack.

All the foregoing concepts amongst others which will be later seen can be considered as further developments of the first mentioned concept to reach to a fully automatic operating equipment.

It should be pointed out that in the known paper making machines between the vacuum boxes and the suction couch a hand operable movable water ejector nozzle is provided which constantly ejects water and which may be hand guided across the entire width of the Web, and which is used during starting operations, as is well known to those skilled in the art.

By starting operation is to be understood any new start including those previously referred to as refeeding.

Prior art arrangements have been unable to guarantee a constant web feeding throughout the entire length of the paper making machine, since there are no means provided for an instantaneous formation of a safety band which will actually ensure that no tear can escape. In addition such equipment cannot detect and successfully repair any tear occurring at any other :air gap and in the most modern machines it so happens that the tears usually occur in the first stack of press rolls.

It is known to those skilled in the art that the prior art mechanical arrangement further requires a lot of space.

Thus, the present invention refers to a method of resorting a running foil-like web when a break starts during the manufacturing process thereof, said method consisting in the steps of detecting the break and simultaneously acting on at least one stationary cutting means arranged substantially on the tear line of the break and adjacent to that edge of the web which is spaced away from said break, to thereby form a safety band outside the tearing zone in the web, which safety band is substantially always capable of continuing towards the finishing end, and thereafter operating behind the tear line and crosswise to the web a movable cutting means from the inner edge of the safety band towards the opposite edge of the web to restore the entire width of the web.

Expressing the above with regard to paper manufacture it may be stated that the present invention refers to a method of restoring running paper web in paper making machines when a break starts during the manufacturing process thereof, said method consisting in the steps of detecting the break and simultaneously acting on at least one stationary cutting means arranged substantially on the tear line of the break and adjacent to that edge of the paper web which is spaced away from said break to thereby form a safety ban-d outside the tearing zone, which safety band is substantially always capable of continuing towards the dry end of the paper making machine, and thereafter operating behind the tear line and crosswise to the web a movable cutting means from the inner edge of the safety band towards the opposite end of the web to restore the entire width of the web.

In a preferred way of carrying out the method of restoring running paper web in paper making machines when a break starts during the manufacturing process thereof, the method consists in the steps of detecting the break and simultaneously acting on at least one stationary water ejector nozzle arranged substantially on the tear line of the break and adjacent to that edge of the paper web which is spaced away from said break to thereby form a safety band outside the tear zone, which safety band is substantially always capable of continuing towards the dry end of the paper making machine, and thereafter operating behind the Millspough suction couch and crosswise to the web a movable water ejector nozzle from the inner edge of the safety band towards the opposite edge of the web to restore the entire width of the web.

Analyzing the invention from its structural viewpoint the former refers to an equipment for restoring running web in foil manufacturing machines, comprising a plurality of air gaps where the foil has to be transferred from one supporting means to the next, each air gap including a watching and commanding station to watch the integrity of the foil and stationary safety band cutting means to he commanded by said commanding station and arranged adjacent said air gaps and on said one supporting means, said stationary safety band cutting means being capable of cutting -a safety band on each side of said foil adjacent to its edges, and at :least one movable foil crosswise cutting means arranged before the first air gap for restoring the total width of said foil.

Finally the invention includes the electric system of the equipment for restoring running paper web in paper manufacturing machines having a web end and a reeling end, the electric system thereof comprising detecting means having for example at least one pair of photoelectric means for independently scanning spaced apart zones of said paper web and for independently starting the operation of a pair of independently operated movable cutting means each including a movable water ejector nozzles, an electric motor and an electromagnetically operated check valve for controlling the ejection of water through said movable Water ejector nozzles and a plurality of spaced apart and lengthwise aligned with regard to the running paper web stationary nozzles each having an electromagnetically 4 operated check valve and being controlled thereby, a first electric triggering means for each of said photoelectric means, a blocking arrangement, each of said first electric triggering means being related to the other first electric triggering means through said blocking arrangement so that when one of said first electric triggering means hecomes operative it blocks the other of said first electric triggering means, a plurality of adjustable time delay devices, other electric triggering means, a common connection for both of said first electric triggering means to energize said plurality of adjustable time delay devices each connected through one of said other electric triggering means to one of said pairs of electromagnetically operated check valves of said pairs of stationary nozzles, said adjustable time delay devices being time delayed in staggered relationship from said wet end towards said reeling end of the paper making machines, each of said first electric triggering means being further connected to one of said electromagnetically operated check valve controlling one of said movable water ejector nozzle for opening its check valve upon becoming energized, further time delay devices, second electric triggering means connected to said first electric triggering means each through one of said further time delay devices, each of said second electric triggering means commanding the start of one of said electric motors, a pair of microswitches in structural relationship with each of said electric motor for controlling the closure of the check valve and the de-energization of said electric motor.

Bearing in mind the above, it will be apparent that it is an object of the present invention to provide a method and means for paper making machines which can survey and eventually automatically restore the web whenever torn, whilst running through the machine from the wet end towards the dry end.

Another object is to provide an equipment for the above mentioned purpose which is so designed that it may be applied to any existing machine, without carrying out substantial modifications.

A further object is to provide an equipment which does not impede the normal cleaning and repair operations, such as changing an endless felt band, the wire fabric, and so on, of the paper making machine.

A still further object is to provide the equipment with visible and audible alarms so that the operator is accordingly advised when the equipment becomes operative.

Another object is to provide commanding means for the felt and drying stacks to reduce the speed of the paper web therein during a restoring action, if necessary.

Still another object is to provide detecting means such as a photoelectric cell in each portion to be surveyed which is related to a radiation or survey beam that is projected either onto the passing paper paste web or onto a blank cylinder and responds to the reflected beam from the same side as projected so that there is no possibility of soiling one of the stations of the cell.

Another object is to provide detecting and control means including for example a photoelectric cell which when surveying the paper paste web permits a certain tolerance in up and down movement of the web in accordance with the requirements, before sending a signal, which tolerance is necessary since the tensional pull on the paper Web is not always constant.

A further object is to provide a device for the movable restoring water ejector nozzle which includes such a short water feeding line that water is ejected with its full pressure and as soon as the water check valve is closed no further water ejection takes place through the nozzle.

Another object is to provide commanding means for the movable restoring water ejector nozzle which enables said ejector nozzle to move along a pendular path of which one of the strokes is an ejecting stroke only.

A further object is to be able to easily change the nozzles so as to adjust the water jet in accordance with the requirements.

Another object is to provide a plurality of adjacently arranged nozzles all of which carry out a pendular movement in staggered relationship, so that when the first nozzle finishes its ejecting stroke, the next nozzle starts its ejecting stroke and thereby any width of paper web may be covered and restored.

A further object is to provide detecting means at each air gap where a break may possibly occur, such as three photoelectric cells, the first of which is arranged above a portion corresponding to one of the outer safety bands and said cell is used in connection with a starting operation of the machine and the other two are mounted in between said safety bands, so that said last mentioned cells survey intermediate portions of the Web for detecting breaks, whereby the right hand cell operates on the left hand cutting and/ or restoring means and vice versa.

Another object is to provide a central electronic commending and control station for the entire equipment.

A further object is to provide each detector or photoelectric cell with signal blocking means to avoid the issuance of a new signal until a pending operation is fulfilled.

Still a further object is to provide tearing means which may produce an intentional break at will or synchronized with the elected break, which in some machines becomes necessary in order to avoid the accumulation of an excessive large mass of paper at any intermediate stage of the machine during a break restoring operation.

A further object is, in case of mass production of the equipment, to provide the detecting means specifically shown as photoelectric cells, with differential amplifiers having reversible polarities to be able to apply the beam of the photoelectric cell either to the paper web or to the bare cylinder, in the first case the cell has to send a no-paper signal when the paper disappears from beneath the cell and in the second case the cell has to transmit a paper signal when paper appears below the cell, thus the same detector or cell structure can be used for both types of installations.

Another object is to provide at least near the end of the machine additional detectors, such as a pair of extra photoelectric cells, one over each safety band, so that when both cells, transmit a signal simultaneously, such as when no paper passes under their inspecting spot, the entire starting system will be deblocked at the same time as they block the restoring system, and furthermore as soon as one of the above mentioned extra cells transmits a second signal, when paper reappears under its inspection spot, it will deblook the restoring system and start to operate a portion thereof at the same time as the starting system is reblocked.

Still a further object is to provide means to eliminate the loose end if any, of the web at a torn portion.

These and further objects and advantages of the present invention will become more apparent during the course of the following description wherein, by way of example, reference is made to a specific embodiment and some possible alternatives in combination with the accompanying drawings, wherein:

FIGURES 1a and 1b are a continuous schematical layout of a paper making machine in side elevation, wherein the position of a number of devices forming part of the equipment, according to the present invention, are shown.

FIGURE 2 is a perspective view of the photoelectric cell arrangement arranged above the air gap beyond the Millspough suction couch.

FIGURE 3 is a perspective view of a movable water ejector nozzle assembly arranged on top of the endless wire fabric stack between the vacuum boxes and the Millspough suction couch, and further shows the known type of hand operated movable water ejector nozzle, it being understood that but one of the two arrangements is used.

FIGURE 4 is a perspective view from the rear end of 6 one unit of the movable ejector nozzle and its drivin and water control parts.

FIGURE 5 is a cross section along line VV of FIG. 4.

FIGURE 6 is a somewhat schematic perspective view of a pair of press rolls provided with a pair of stationary cutting means and three photo-electric cells two of which control said pair of cutting means for producing a pair of outer safety bands and the third belonging to the starting system.

FIGURE 7 is a schematical perspective view similar to part of FIG. 3 of a single unit.

FIGURE 8 is a plan view of part of the paper web above the Millspough suction couch adjacent portions thereof and the first press roll stack.

FIGURE 9 is a view similar to FIG. 8 but showing only a part thereof to illustrate the start of a crack before being detected by the corresponding photoelectric cell.

FIGURE 10 is a similar view as FIGS. 8 and 9, showing the further development of the crack as well as what happens after one of the crack control cells has detected the crack.

FIGURES 11 and 12 are similar views as FIGS. 8 to 10, but showing the successive development of restoration of the total width of the web 'by means of the movable ejector nozzle.

FIGURE 13 is a perspective view showing how a crack may start in an intermediate portion of the web.

FIGURE 14 is a schematical plan view of the cell arrangement at the bobbin reeling end.

FIGURE 15 is a perspective view of an alternative embodiment of a scraper arrangement.

FIGURE 16 is a schematic circuit of the commutating system of one of the photoelectric cells.

FIGURE 17 is a schema-tic circuit of the control arrangement for the electric motors driving the movable waiter ejector nozzles and related parts.

FIGURE 18 is a schematic circuit of the first and second thyratron stages in detail, which are shown in block form in FIGURE 17.

FIGURE 19 is a functional block diagram of the electronic arrangement.

FIGURE 20 is a schematic circuit of the starting arrangement.

In FIGS. 1 a Fourdrinier machine is schematically shown having a wet end ll including a breast box 2 for supplying the pulp slurry onto a wire fabric 3 driven by driving cylinder 4%. The upper portion of the wire fabric 3 passes over a drainage section 4, a suction section 5 consisting of a plurality of vacuum boxes 6 and a couch roll 7 usually of the Millspough suction couch type; to this the usual amount of guiding rolls is added such as rolls 41 and 42. This stack has to remove the major portion of water from the pulp slurry and to consolidate the Web. Further details such as deckle straps and the like known to the trade are not shown.

The paper paste web 8 thus formed is transferred from the Millspough suction couch through a first air gap 9 onto a first continuous travelling endless felt It passing through a first pair of press rolls 11, 12 of which roll 11 is again of the suction type and roll 12 is usually of the stone type. This portion can be defined as the first stack of press rolls which includes a nip roll 13 wherefrom the paper paste web 8 is transferred through a second air gap 14 onto a second continuous travelling endless felt 15 including a second pair of press rolls 16, 17 similar to the first pair of press rolls and also including a nip roll 18.

The paper web 8 is then transferred through a pair of guiding rolls 19, 20 to a third pair of press rolls 49, 56 including a third continuous travelling endless felt 23 and likewise a nip roll .24 wherefrom the web 8 passes through a third air gap :25 onto a stack of steam heated cylinders 26, 27, 28, 29, 30, defining a drier stack including a continuous travelling endless felt 32 and a felt drier 7 drum 37. It is to be noted that between each pair of cylinders a corresponding air gap exists. Corrector rolls 43, tensioning rolls 44 and guiding rolls 45 for each of the endless felts are likewise shown in FIG. 1, no explanation is necessary, since they are well known in the art.

From the drier stack the paper web 8 passes over a guiding roll 31 which may be heated or not, and therefrom through a considerably larger air gap 34 to a calendering section 35 and therefrom again through a rather long air gap 36 to the reel 38 for forming the final bobbin 39.

Actually the paper exit end 33 may be considered as the dry end of the Fourdrinier.

Whilst the description of the above Fourdrinier is merely given by way of example to facilitate the explanation of the invention, it will be obvious that such a description is not a binding one and likewise no further details will be given thereabout since these machines and their way of operating are well known in the art.

Although reference has just been made to a Fourdrinier machine, it is obvious that any other type of paper making machine or other foil manufacturing machine may be used.

Every time the paper web 8 has to be lifted from one drum or roll or the like to pass through an air gap to the next, there is a tendency of the web to remain adhered to said drum, roll or the like and if in the Web a weak portion or a cut or the like is present, said portion actually remains adhered to the drum, roll or the like and thus starting a break which very fast runs across the entire web, as is known in the art. Therefore, if such a break starts for instance at the Mi-llspough suction couch 7 (FIG. 1a) the portion which remains adhered will turn with the suction couch 7 and remain adhered on the lower portion of the wire fabric 3 until said wire fabric is washed, such as by nozzles 46, whereupon that part of the paper paste web will fall into a sink (not shown), as is likewise known in the art.

The same tendency of adherence and tearing of the web 8 exists in all the other transfer stations; thus for instance at the stone .press roll 12, the paper paste web tends to be raised and so reenter upon a complete turn of roll 12 between the pair of rolls 11 and 12 on top of the web supplied from the Millspough suction couch 7, which of course is not admissible. Therefore usually at the upper portion of the press roll 12 a scraper 47 is arranged which scrapes oh? the adhered web. Similar scrapers 47 are provided wherever such a scraping action is necessary.

It should perhaps still be stated, although this is likewise known, that in the drier stack an excessive accumulation of scraped off paper web presents the danger that the amount may fall back between any of the steam heated cylinders 26, 2S and 3t and the continuous travelling felt 32, whereupon the pressure between them is such that it invariably breaks the cylinders and an unforeseeable dangerous situation may develop.

To assure a continuous operation of the machine and a restoring action when a break starts, means are provided for forming at least one, preferably two, safety bands, to which reference will be made later with more details, and further means are provided for restoring the entire width of the Web. To achieve this, it is necessary to provide at each 'air gap or transfer station of the web 8, a watching and commanding station for controlling the normal running of the web 8 and in case such a run' ning becomes abnormal, to immediately command cutting means for the formation of the safety band or bands in the web 3 and simultaneously or immediately thereafter to start the operation of the restoring means. These watching and commanding stations have been schematically indicated in FIGS. 1a and 1b by means of a little square with an arrow and all have been identified by reference numeral 48. The little square indicates the mechanical and electronic means and the arrow the direction of the survey beam, although in practice both means are spaced apart.

It will be seen that such watching and commanding stations in the machine, as shown in FIGS. la and 1b, are arranged above the first air gap 9; between the nip roll 13 and the press roll 12 and above the paper web 8; bet-ween the nip roll 24 and the press roll 49 forming part of the pair of rolls 4% and 5t usually of rubber; in the air gaps existing between the pair of heated cylinders 2627, 2728, 2829, 29 3o and Bill-31; and finally above the air gaps 34 and 36.

In this arrangement a single remote controlled movable cutting means 51 for restoring the total width, the damaged web, starting from either one of the safety bands, is provided, which movable cutting means is arranged above rthe paper paste web 8, between the guiding roll 41 and the Millspough suction couch 7 (FIG. 1a).

Reference numeral 52 indicates the position of a schematically shown hand operated movable water ejector nozzle 52, which as such is known and which may replace in a more economical embodiment the remote controlled movable cutting means 51.

In some machines it may be advisable to have several stations of remote controlled movable cutting means, such as if a number of breaks take place near the dry end 33, and to avoid that the restoring action takes place near the wet end 1 and thereby a long distance has to be run through by the web as a safety band, before being actually restored to its normal width, as will be obvious to anybody skilled in the art. Although the remote controlled movable cutting means 51, as will be later seen, is here operated by means of a movable water jet, it is evident that such a water jet may for instance be replaced by a cutting knife or the like if said remote controlled station is to be arranged near or behind the dry end 33, since the paper web is there already so consistent that such a cutting means may be more suitable. In addition, if this arrangement is for instance used in plastic film-like material manufacturing machines, the cutting means as such may be of any suitable type in accordance with the material to be manufactured and thus the description which follows with regard to the embodiment shown in the drawings, :by way of example, will have to be interpreted in such a Way that the cutting means used, that is to say water, can be replaced by any other suitable agent or device.

Since the complete equipment representing the present invention is rather of a complicated nature, not so much because of its apparatus and devices, that is to say from the structural viewpoint, but because of the simultaneous synchronized operative steps, that is to say from the functional viewpoint, it will be best first to describe it from the mechanical viewpoint omitting the electronic aspect and thereafter said electronic aspect will be separately described in summarized form, since those details of the circuits which are within the normal skill of an expert do not form part of the invention.

In FIG. 2 a first photoelectric cell control station 53 is shown which forms part of a watching and comm-anding station 48. More particularly the photoelectric cell control station 53 shown is that arranged above the air gap 9, that is to say behind the Millspough suction couch 7. For further references part of the wire fabric 3, part of the first continuous travelling felt it) and two of the guiding rolls are shown, as well as the pertinent portion of the paper web 8. The size of the air gap h is slightly exaggerated.

At any suitable portion of the frame 54 of the paper making machine, a pair of hinges 55 supports a pivoted hollow supporting bar 56 on which a start control photoelectric cell 57, and a pair of intermediate photoelectric cells namely left hand cell 59 and right hand cell 60 are mounted. Each of the cells 57, 59 and 60 is connected to a bundle of conductors (not visible) housed in an insulated steel sheath 61 entering the hollow supporting bar 6 and therefrom to the central remote control commanding station 62 (see FIG. 1a).

The start control photoelectric cell 57 has to watch a zone corresponding to the left hand safety band 63, only indicated by dotted lines since under normal operation circumstances it is not physically spaced apart and visible from the entire web 8. Cell 57 forms part of an electronic arrangement for commanding the necessary means, which will be later described, :for carrying out a starting action to guide the web from the wet end 1 towards the dry end 33.

The pair of intermediate photoelectric cells 59 and 6% functions to watch the intermediate zone 65 existing between the left hand and right hand safety bands 63, 64. These cells 59 and 60 are the agents to detect any break crosswise passing through their scanned sections and to immediately report such a break to the central remote control commanding station 62 (FIG. la) in order to start the necessary mechanical means for stopping the break and thereafter to restore the torn portion.

It may already be observed that the right hand cell 60 commands the left hand mechanical means and the left hand cell 59 commands the right hand mechanical means, more particularly the safety band cutting means and the web width restoring means, as will be later seen.

There are a number of important details in connection with the cells themselves, of which a first one is the fact that each cell 57, 59 and 61} as shown in FIG. 2, is of the reflector type, that is to say (see cell 57) that the transmitting station which transmits a ray-beam 66 and the receiving station which receives the reflected ray-beam '67 by reflection (in this case) on the paper web 8, are located on the same side with regard to the web 8 and therefore may be housed in a common casing 68. Thus, no staining action on the detection system with the previously referred to consequences, is possible.

The sensitivity of each cell is so graduated that an abrupt change of the reflecting surface and therefore a pronounced variation of the reflected beam 67, such as for instance if the paper web 8 disappears, is immediately reported by the receiving station to the central remote control commanding station 62 (FIG. la) which amplifies the signal of the receiving station and starts to act the necessary mechanical means. It will be understood by those skilled in the art, that the distance existing between the ray-beam receiving station and the reflection spot on the web does not remain actually constant, since the web 8 may be subject to a slight undulatory movement, and yet the web 8 remains intact. Thus the sensibility of the cell must furthermore be so graduated that rather slow variations, such as due to undulatory movements and the like, and for instance a slight variation in the color of the web 8 which obviously varies the intensity of the reflected ray-beam 67, are not reported to the central remote control commanding station 62. Thus, the necessary means must be supplied in the electric circuit of the cell, as will be seen later on, to achieve such a result.

Referring in general terms to the electric circuit of the cells, it should be stated that blocking means are provided which do not allow the central commanding station 62 to transmit the cell signal of the other group, either 59 or 60 commanding impulse, until a previously started operation has been completed.

As to the specific object of the outer cell 57, the latter has to report during the starting operation when the start band which may be of the same width or smaller than the safety band, starts to pass thereunder. It is known that to start the web from the wet end 1 towards the dry end '33, that the web which will be lifted from the Millspough suction couch 7 is of a small width with regard to the entire width of the web to be manufactured. Such a starting band would have the tendency of remaining adhered to the wire fabric and turning around the cylinder of the Millspough suction couch 7 instead of passing through the first air gap 9 onto the first continuous travelling felt 10. Thus, when a starting action is being performed, whilst cell 57 does not report the passage of the start band 58 which in this particular case is part .of the width of the safety band 63-, which passage cannot be reported until said starting band 58 is lifted from the wire fabric 3 since ray-beam 66 scans a portion over the air gap 9, the central commanding station operates an air ejector nozzle 69 shown in FIG. 2, in this case housed in the Millspough suction couch '7, which blows through the wire fabric 3 over a section the width of which is substantially equal to that of the start band 58. The moment the beginning or free end portion band 53 reaches the portion subjected to the air blow, said free end portion is detached from the wire fabric 3 and blown upwardly, and since continuously a further supply of start band web 58 comes along, all that further supply is likewise detached from the wire fabric 3 due to the air blown from nozzle '69 until the free end portion of the band 58 falls onto the first continuous travelling felt 1th to which it adheres and continues its path along with said felt 10'. Thus a moment will come where the tension of said starting band 53 is substantially normal and thus the distance existing between the receiving station of cell 57 and the web is normal, whereby a second impulse is sent by the receiving station to the central commanding station 62 which stops the operation of the air ejector nozzle 69. A similar arrangement and procedure is repeated through all the air gaps and its watching and commanding station 48 (see FIGS. la and lb), whereby it will be possible to lead such a starting band 58 through the entire length of the machine. It has to be added that as to the long air gaps 34 and 36 (see FIG. 1b) the air ejector nozzles 69 and 69" work in combination with respective starting band guiding channels 70 and 71 which suitably guide the free end portion of the starting band 58 into the calendering section 35 and onto the reel 38 or bobbin 39, as the case may be, respectively.

It has to be added, as shown in PEG. 14 that above the air gap 36 the photoelectric cell control station 48 comprises the usual break detecting cells 59 and 6b and the start control photoelectric cell 57, and in addition thereto a fourth cell 1% which surveys the zone corresponding to the right hand safety band 64. The pair of cells 57 and 146 actually control the starting operation. As has been previously stated all the cells 57 and their homologues are blocked, unless a starting operation is initiated. Now in order to automatically advise the central commanding station when such a starting action should be started, it must be somewhere detected that no Web is supplied to the bobbin 39, and by no web is to be understood neither the entire web nor any of the two safety bands 63 and 64. Thus since cell 57 scans the starting band 58 and since starting band 58 is part of the safety band 63 if both cells 57 and 146 transmit simultaneously an impulse informing that no web passes under their inspection spots, this will be the necessary command for the central commanding station 62 to electronically deblock the entire mechanical, hydraulic and pneumatic starting systems, as will be fully understood when analyzing the electronic part.

As to the specific object of the pair of photoelectric cells 5? and 64 these have to scan the web 8 for possible cracks, so as to report them and start the necessary safety and restoring actions as will now be seen.

Means are provided in the electric circuit of the pair of start control photoelectric cells 57 and 146 (as will be later seen) which do not allow cells 5'7 and the homologues to transmit an impulse in case a break should pass through their inspection spots which actually may happen, and which has nothing to do with a starting action, in other words no air blow is required. In FIG. 2 all the three cells 57, 59 and 66 are shown as transmitting each a beam simultaneously, but it would be of course possible by means of the central, commanding station s2. to switch off cells 57 or cells 59 and 6%, while the other is or are operative, since both sets of controls are completely independent one from the other.

Before explaining however the safety and restoring actions in relationship with the pair of intermediate photoelectric cells 59 and 6% it will be necessary to explain the mechanical means thereof, analyzed from the structural View point.

To this end reference will now be made to FIG. 6, wherein by way of example the first pair of press rolls 11 and 12 is shown in combination with the first continuous travelling felt in, a scraper 47, a start control photoelectric cell 57', and a pair of restoring photoelectric cells 59 and 60 similar to cells 57, and 60 (FIG. 2).

As previously explained, in case the web 8 is turned, the turn portion tends to remain adhered to the upper press roll 12 and is raised therewith until reaching the scraper 47 which will scrape the web off the press roll 12. In order to avoid accumulation of paper on the scraper 47 the latter is provided in this embodiment with a plurality of air ejector nozzles 72 which blow said paper sidewards out of the machine. These air ejector nozzles 72 may either constantly operate or intermittently, in which last case they are usually controlled by a time relay. In FIG. 15 an embodiment is shown wherein nozzles 72 are replaced by an endless screw conveyer M7 which will discharge the paper web over slide 148.

Whilst the cells 57, 59' and 60' are shown as scanning the paper Web 8, it is obvious that if desired they could be so arranged that they would scan the surface of the press roll 12, in which event the polarity of the corresponding cell circuits (as will be seen later on) will have to be inverted so that, as to the pair of cells 59 and 60', they would report or transmit an impulse as soon as web appears under their scanned surfaces and as to the cells 57' it would stop the ejection of air of the side nozzles 69a and 6% (FIG. 6) as soon as the respective starting band paper web 58 disappear from the scanned surface.

Assuming that the left hand cell 59' detects a break (the manner in which breaks are formed, the type of breaks and the method of detection will be explained later on), said cell 59 will send an impulse to the central remote control commanding station 62 (FIG. 1a) which immediately, that is to say practically instantaneously, will open an electromagnetic water control supply valve 73 (FIG. 6) mounted on a water pipe line 74 arranged behind the pair of press rolls 11 and 12 and above the paper web 8. Said valve 73 commands a stationary water ejector nozzle 75 which will eject a small and strong Water jet onto the paper web 8, thereby forming a clear cut therein and thus the safety band 64 is formed and spaced apart from the central injured web 8.

Similarly, if the right hand cell 60" detects a break, electromagnetic water control supply valve 76 is opened and the stationary water ejector nozzle 77 forms the safety band 63.

This crosswise arrangement of the cells 59, 60" with regard to the stationary nozzles 75-, 77 is the preferred arrangement, so as to give the safety band start portion a certain additional time to reach the break line, as will be later better understood.

Obviously the crosswise arrangement is not to be considered as a limiting feature; furthermore in practice either of the intermediate cells 5%, 60' will operate simultaneously both electromagnetic water control supply valves 73 and 76, to further increase the safety coefiicient. Finally, instead of arranging the water pipe line 74 behind the pair of press rolls 11 and 12, said pipe line could be arranged below the web 8 and above the felt 10. It is only important that the water jet pierces through the Web and meets a supporting surface such as the felt 10* or the roll 12. Instead of using water jets any other suitable cutting means, as previously men tioned, may be used.

The arrangement described in connection with FIG. 6 is to be considered as the watching and commanding station 48, schematically indicated in FIGS. 1a, and 1b, so that it will now be obvious to those skilled in the art that such an arrangement is repeated as many times as required, that is to say at every air gap.

The actual functional relationship of the formation of the safety band in order to stop a propagating break and the manner in which the torn portion of the web is restored, will be explained later on after the mechanical, structural and functional details of the remote controlled movable cutting means are described, as will now be As to the movable cutting means, reference will first be made to FIG. 3, wherein at the height of the guiding roll 41 the hand operated movable water ejector nozzle 52 is shown, to which reference was already previously made in connection with FIG. 1a. In FIG. 3 the wire fabric 3 and also the remote controlled movable cutting means 51, as well as the paper web 3, here still in form of paste, are again visible. Furthermore, as is likewise known already in the art, the edges 8' of the paper paste web are irregular and thus, near the edges 8' and between the vacuum boxes 6 and the guiding roll 41 (see FIG. 1a), a pair of water ejector nozzles 78 (see FIG. 3) establishes a clear cut so as to form a left hand straight edge 79 and a right hand straight edge 80 in the paper web 8 which will continue towards the dry end whilst the very small strips 81 will move along with the Web and then be separated therefrom when the wire fabric 3 turns about the Millspough suction couch 7 to be finally separated from the wire fabric 3 by nozzle 46 (see FIG. 1a); it has to be pointed out that strips 81 are not shown in FIG. 2 where they ought to be visible, in order to avoid overburdening of this drawing, particularly since this feature as such is known in the art.

Returning now to the hand operated movable water ejector nozzle 52, the latter consists of an U shaped guiding tube 82 supported by supports 83 and 84 and in which a conduit 85 is slidably housed, one end of which is connected through a control valve 86 to a Water supply line 87 whilst the other end emerges through the U-shaped guiding tube by means of projection 85' which supports a water ejector nozzle 88 provided with a hand operable needle cleaning means 89. By pulling control valve 86, conduit 85 will slide in the U-shaped guiding tube 82 in the direction of arrow 90 thereby moving the water ejector nozzle 88 from the right edge of the wire fabric 3 towards the left edge. By opening valve 86 water will be ejected through nozzle 88.

Thi hand operated movable water ejector nozzle arrangement 52 was hitherto used during the starting operation to form therewith for instance the starting band 58, which is separated from the entire web and hand guided through the different stacks onto the reel 38 (see FIG. 1b). During the time required for hand feeding the starting band 58 onto the reel 38 the remaining portion of the paper web 8 will move around the Millspough suction couch 7 together with the fabric wire 3 and be discharged therefrom by means of the nozzles 46 (see FIG. la). Once the starting band 58 is reeled onto reel 38 (FIG. lb), the axis of water ejector nozzle 88 (FIG. 3) is moved in opposite direction to that of arrow 0, thereby linking by means of a cut the starting band gradually to the rest of the web which gets wider and wider until finally the entire width of the web forms an integral web which will pass through the different stages to the reel 38. In FIG. 12 the shape of the web while passing through the stacks to finally reach the total width, is shown.

In the simplest way, that is to say the most economical way, the present invention could therefore be so conceived that when nozzle 77 (see FIG. 6) cuts the safety band (and it has to be borne in mind that a similar nozzle 149 could be arranged on the suction couch 7, FIG. 8 in front of the hand operated movable water ejector nozzle 88, FIG. 3 and that the photoelectric cell 60', FIG. 6, acts on the central remote control commanding station 62 to indicate the side of the safety b and), it would be possible to manually restore, the entire width of the web 8 with nozzle 88 (FIG. 3), as above described. The above referred :to similar nozzle 149 need not necessarily be provided if the nozzle 88 is first located at a position equivalent to said similar nozzle 149 so a to form there the start of the safety band 63, but this would have the drawback that a safety band could only be formed on one side.

As such obviously it would be possible to start the above described restoring action also from the other edge in which case an additional nozzle (FIG. 8) should be provided.

It is important to point out that Whichever of the two water ejecting paths the nozzle 88 carrie out as a Working stroke, the return stroke has to be carried out without any water ejection.

In practice this system is however much too slow and might perhaps only be used in connection with some very slow paper manufacturing machines, since in the high speed machines, the production loss, as referred to the time required in restoring the web to its total width, is too nigh, so that remote controlled movable cutting means are to be employed.

In FIG. 3 a remote controlled movable cutting means 51 of the multi-nozzle type is shown, Where the Width of the paper to be manufactured is of approximately four meters, thus each nozzle, since there are two independently operating series of four nozzles will cover a width of one meter. It will be understood that if the width of the web is only for example one meter, that one nozzle of each series, which is a total of two nozzles, will be sufficient.

In first instance it is to be pointed out that the remote controlled movable cutting means 51 may be lodged at the same place where the hand operated movable water ejector nozzle 52 is usually arranged. In the embodiment illustrated the remote controlled movable cutting means 51 is arranged ahead of the hand operated movable water ejector nozzle, so that both arrangements 51 and 52 may be simultaneously shown, although if the machine is equipped with a remote controlled movable cutting means 51, the hand operated movable water ejector nozzle 52 will usually be disconnected or can directly be eliminated.

In the embodiment shown in FIG. 3, the remote controlled movable cutting means 51 consists of a frame 91 including at the lower part two tubular members 92 and 93 of which tubular member 92 is used as a main water supply pipe and tubular member is used as a main housing for electric cables which connect each of the cutting means units 94 and 95 of which units 94 represent one series and, units 95 the other series. Furthermore, for this embodiment a special start unit 151 having a nozble 154-, is likewise provided.

Frame 91 projects over both side edges of the wire fabric 3. One end portion of frame 91 is pivotally mounted on hinge 96 whilst the other end merely rests on support 97 so that it is possible to lift the entire frame, as will be necessary when one wire fabric is to be replaced by a new one.

As may be seen in FIG. 4, wherein one unit d4 is shown, the structural details of which are identical with units 95 and 151, said unit )4 comprises a housing )3 in which two U-shaped cross bars 99 are mounted on the bottom plate 191} of housing 98 of which the rear plate 1111 and top plate r192. have been removed. The main water supply pipe 92 comprises for each housing 98 and L-shapcd branch 103 which enters housing 98 through one of the side plates 104 and is connected to an electromagnetically operated check valve 1195 supported by one of the U- shaped cross bars 99 and connected to one end of a hex- 1d ible hose 1% the other end of which is connected to a pipe 107 rotatably supported by bearings 1118 in a frame 1B9 likewise supported on cross bars 99. Pipe 107 passes through the front plate 110 of housing 98 where it ends into a downwardly projecting arm 111 (see FIG. 5) the free end of which is provided with an interchangeable water ejecting nozzle 112.

Returning to FIG. 4 frame 109 further supports a synchronous electric motor 113: the rotor (not shown) of which rotates at 78 rpm, having an upwardly projecting driving shaft 1114 (FIG. 5) including a free end 114- abutting against a ball 115 controlled by screw 116 housed in a cross piece 11'! supported by a frame 10%. The middle portion of driving shaft 114 is provided with a worm 118 meshing with a worm wheel 119 mounted on shaft 12% supported by bearings 121 arranged in frame 1419. Shaft 126 projects through one of the plates defining frame [169 and supports a disk 122 having an eccentric pin 1Z3 supporting a connecting rod 124- linked to one end of a crank shaft 125, the other end of which is connected to pipe 107. Disk 122 comprises a peripheral cam 126 capable of operating the water-supply interrupting micro-switch 127 and also the electric motor stopping or limit micro-switch 123. A bundle of electric cables 129 is branched off the main bundle of cables (not visible) housed in tubular member 93 and supplies the necessary connections to the central remote controlled commanding station 62 (FIG. 1a).

To explain the operation of cutting means unit 94, reference will first be made to FIGS. 4, 5 and 7. In FIG. 7 one unit 94 and one unit 95 are shown which are sufficient for restoring a web 8 of one meter width.

Assuming that a break has been detected by the right hand photoelectric cell 60 (FIG. 7) as will be later seen, said cell 6% transmits a signal to the central remote controlled commanding station s2. (FIG. 1a) which starts to operate unit 94 (FIG. 7) by opening electromagnetic operated check valve 185 (FIG. 4) which permits the passage of water under pressure from the main Water supply pipe '92 through L-shaped branch 1113, check valve 105, flexible hose 1%, pipe 107, downwardly projecting arm 111 (FIG. 7) to nozzle 112, which immediately projects a jet 1 30 to start the safety band 64. A short time thereafter although it could be at the same time the electric motor 113 (FIG. 4) starts to rotate through its shaft 114 (FIG. 5), worm 118, Worm wheel 119, shaft disk 1Z2, connecting rod 124, crank shaft (FIG. 4), pipe 1617, the downwardly projecting pipe arm 111 (FIG. 7) with nozzle 112 to describe an are a which on the web is transformed into a cross wise rectilinear path from point A to point B; point A being at the right hand safety band incision 152 forming the safety band 64 and point B lying outside the intermediate zone 65 and safety band 63. When nozzle 112 has reached the position corresponding to point B, earn .126 (FIG. 4) has operated and passed by the water supply interrupting micro-switch 127 thereby transmitting a signal through the central cornrnanding station 621, to the eleotromagnetically operated check valve which is thereby closed while the motor 113 and its related parts keep on running, thereby returnin the nozzle 112 to its start position without any water being ejected until cam 126 acts on electric motor stopping micro-switch 128, in turn transmit-ting a signal through the central commanding station 62 to stop the current supply to electric motor 113, which then stops.

Similarly if photoelectric cell 5% (FIG. 7) detects a break, unit 9'5 becomes operative whereby its water ejector nozzle 112 ejects Water to point C which corresponds to the left hand safety band incision 15?; forming the safety band 63 to point D outside safety band 64 and returns without ejecting water from point D to point C.

During the entire operation an audible and/or visible alarm signal is likewise produced, as will be better seen when analyzing the electronic arrangement as shown in FIG. 19.

If the width of the web 8 is considerably larger, the arrangement as shown in FIG. 3 as far as the remote controlled movable cutting means is concerned, is operated, wherein the right hand outside unit 94 starts to eject water through nozzle 112 at point A similarly as described in connection with FIG. 7 to reach point A and then sends an additional signal to the central commanding station 62 which in addition to returning nozzle 112 from point A to point A, starts the second unit 94' which move and form a cut from point A to point A and there the cut is transferred to the third unit '94 which will carry on the cut from point A to point A which then will start the last unit 9411 which will carry the cut from point A to point B. A similar operation but in the opposite direction can be performed by units 95, 95', 95" and @541. Thus by suitably increasing or decreasing the number of units 94 and 95, any width of paper web can be covered.

It has to be added that from the practical viewpoint, it is advisable that all the nozzles 1.12 or 112 start to eject the water simultaneously and furthermore that there should be a slight overcrossing or overlap of two adjacent water jets, instead of meeting at a point, more particularly, with regard to FIG. 3, when the first nozzle moves from A to A Bearing in mind that the second nozzle starts to eject water when the first nozzle starts to eject Walter on A, said second nozzle should eject on point A instead of A so that the segment A A is twice covered, and so on, to assure continuity.

The mechanical advantage of the above described unit 94, and more particular the pendular movement of the downward projecting nozzle arm 111 (FIG. 7) resides in the fact that the length of the water supply pipe from the check valve 105 (FIG. 4) to the nozzle 112 is rather short and thus the start and finish of the water ejection can be practically instantaneously controlled. if instead of the pendular arrangement a single rectilinear moving nozzle of the type of nozzle 88 (FIG. 3) were provided, the length of the water supply pipe from the check valve to the nozzle would be so long, particularly if the webs width is large, that no instantaneous water start or cut could be achieved, with drawbacks which are obvious.

While so far only reference to breaks starting from either of the left hand straight edge 79 or right hand straight edge 81 (FIG. 3) has been made, it will be apparent :to those skilled in the art, that a break may likewise start in the intermediate zone of the web 8, as is for instance shown in FIG. 13. The Millspough suction couch 7 is again shown indicating the way a portion 131 that is sufficiently weak remains adhered to the wire fabric 3 and turns around the suction couch 7 so as to start a triangluar break 132, the sides oat which will diverge so that one of the cells 59 or 61) will sooner or later detect it.

Having thus described .the structural details of the arrangement, reference will not be made mainly to FIG- URES 8 to 12 to describe a restoring action from the functional view point in order to better understand the systems synchronization.

In FIG. 8 part of the paper making machine is shown during normal operation more particularly wire fabric 3, guiding roll 41 and the M'illspough suction couch 7 as well as the air gap 9 (slightly enlarged), the guiding roll 45 with the first continuous travelling felt 10 and the suction couch press roll 11. As at the suction press roll 11, any other watching and commanding station 48 is of the same layout. The paper web 8 is shown without any lbreak, thus the machine is operating in its normal way.

As to the water ejecting nozzles shown in FIGS. 8 to 12, the following conventional symbols are used: The nozzles which are shown in full lines by means of a small circle are operative whilst those others shown by dotted lines are inoperative, that is to say at that moment they do not eject any water. This conventional arrangement for the above mentioned figures will facilitate the operative analysis thereof.

li e

Thus in FIG. 8 it may be seen that water ejector nozzles 78 are operative and therefore are able to cut away the outer strips 81.

The movable Water ejecting nozzle 112 and 112' are those corresponding to the arrangement shown in FIG. 7 and they are inoperative in FIG. 8. It has to be borne in mind that in FIG. 8 the points where the water jets will pierce the paper Web are shown, that therefore nozzle 112 which corresponds to point A is shown on the other side of the web as in FIG. 7 and similarly nozzle 112' which corresponds to point D. Although nozzles 112, 112' and 154 are inoperative, for illustrative purposes the incision lines 152 and 153 which the first two would be able to cut to form the safety bands 63 and 64, are shown in dotted lines, furthermore it will be appreciated that due to those dotted lines it is possible to appreciate the position of the stationary water ejector nozzles 75, 7'7, 149 and 150 likewise shown in dotted lines since at this instant they are inoperative. In this case the nozzles 75 and 77 are shown behind the pair of press rolls 11 (and 12, not shown) similar as in FIG. 6 although obviously those nozzles 75 and 77 could be arranged in the other position, as previously explained or both arrangements could be provided simultaneously. In FIG. 8 the movable nozzles 112 and 112' when in their start position, are alined with the stationary nozzles 75 and 77, and 149 and 150 if existing although in practice it is sometimes preferred that nozzles 75, 77, 149 and 150 are located a little bit more towards the straight edges 79 and 80, respectively, to be certain that they will be within the safety bands 63 and 64, if an operation is started.

Finally in FIG. 8 the pair of break detecting cells 59, 60 and 59, 60' as well as the start control cell 57 are schematically shown.

It has to be added that above the first air gap 9 a strong Water ejecting nozzle 133 is schematically shown, the ejector axis 134 of which is directed towards the center portion of the intermediate portion 65 and onto the air gap adjacent the Millspough suction couch 7, so that it operated a voluntary intentional cut or break may be produced in the web for purposes which will be later explained. A series of fixed nozzles may be used in place of the single nozzle 133. Arrow 135 indicates the direction of movement of the paper Web 8.

Turning now to FIG. 9, wherein only a portion around part of the Millspough suction couch 7 is shown, it will be appreciated therein how a break 136 starts from the edge 79. Said break 136 is defined by a first edge 137 and a second edge 138, whereby the tension exerted on the first edge 137 by the directional pull of the web in direction 135 will move said crack 136 along the tear line 139 which corresponds to the line of the Millspough suction couch 7 where the web 8 is lifted therefrom to pass onto the felt 10 through the air gap 9. The portion of web 8 which is supplied from the wet end 1 at the part of the second edge 138, will remain adhered to the wire fabric 3 and turn over the Millspough suction couch 7 to be washed oh by nozzles 46 (see FIG. 1a). At the instant shown in FIG. 9 nothing has still happened as far as the restoring equipment is concerned since the break 136 is not as yet detected by the photoelectric cell 60.

Turning now to FIG. 10, wherein the further development of break 136 is shown, it will be appreciated that as the web 8 moves along in direction 135, a moment will come when the first edge 137 defines with the second edge 133 already such a large recess, that the photoelectric cell 61) transmits a signal, schematically shown by arrow 14%, to the central commanding station 62 (FIG. la). Since the first edge 137 of break 136 has in FIG. 10 already past a very short time ago the photoelectric cell 69, it will be understood that the signal 140 was transmitted likewise a short time ago and at that moment nozzle 112 started to eject water, whilst nozzle 112 remains inoperative according to the first embodiment previously described. In the instant case and more par- 17 ticularly in FIG. the moment signal 14!) was transmitted, movable nozzle 112' starts to eject water and thus the safety band 63 is formed. There is a certain time delay until the downwardly projecting arm 111 (FIG. 7) starts to rotate which time delay corresponds to the distance t and during which time the safety band 63 has two parallel running edges 8t} and 141. This time delay is so graduated that edge 141 will enter the air gap 9 so as to be sure that the safety band 63 enters said air gap 9 before the running vertex V of the break 136 will reach the safety band 63. Thereafter the downwardly projecting arm 111 and therewith its nozzle 112' will start its rotary movement so that, as shown in FIG. 10, an oblique incision 142 starts to form due to the composite movement of the nozzle 112 in direction 143 and the paper web 8 in direction 135. The portion of paper web corresponding to the second edge 138 of break 136 is further discharged by the nozzle 46 (FIG. la). Alternatively if desired or advisable depending on the type of machine used, the rotary movement of arm 111 could start instantaneously with water ejection through nozzle 112' in which event edge 141 disappears.

Turning now to FIG. 11, the restoring action is further shown in that the vertex now identified as V, see FIG. 10, was captured by the oblique incision 142, and the movable nozzle 112 has moved further on in direction 143 whereby the vertex V is now held back at position V, and the safety band 63 has already safely passed air gap 9 and lies now on the first continuous travelling felt 11 The point of juncture is identified as Vj, the first edge 137 of the crack likewise lies on felt 10. Between vertex Vj and the start portion of edge 141 and part of edge 137 a triangular flap is formed which in some machines becomes a flying loose end which represents a danger since it may flip over on the safety band and ruin the latter. To avoid it stationary nozzles 156, 157, 158 are provided in the intermediate zone v65, which start their ejection a short while after the ejection of either nozzles 112 or 112. The water jets from the stationary nozzles 156 and 158 overlap with the water jet formed by the stationary nozzle 157. The water jets of the nozzles 156 and 158 respectively do not extend beyond the safety sideband cuts formed by the stationary nozzles 75, 77, 149 and 151 Thus when the stationary nozzles 156, 157 and 158 are brought into operation the triangular flap is separated and scraped off the next cylinder. It will be appreciated that a short time before the instant shown in FIG. 11, the photoelectric cell 59 was without paper web underneath but yet no signal was emitted due to the fact that during a restoring action both cells 59 and 60 are inoperative, as will be later understood. As to cell 57, the latter is always blocked during a restoring action. The details as to how the blocking is carried out will be seen when the arrangement is analyzed from the electronic view point.

Finally in FIG. 12 the moment is shown where movable nozzle 112' has passed over the strip 81 onto the wire fabric 3 and the water ejection has stopped and nozzle 112' is about to return to its start position C without ejecting any water. The position of movable nozzle 112' shown in FIG. 12 corresponds to point D shown in FIG. 7. It will be appreciated that at this moment the entire web 8 is relinked and the moment vertex V" disappears, an undamaged Web 8 passes again over the Millspough suction couch 7 to felt 1i and in due time will reach the bobbin 39 (FIG. 1b).

Obviously if the break is detected by the left hand cell 59 instead of the right hand cell 65), the restoring action is carried out by movable nozzle 112 in the direction indicated by arrow 144 (see FIG. 8).

If a break starts for instance on the pair of press rolls 11, 12 (FIG. la) and assuming that it would start likewise from the left hand straight edge 79, as already explained in connection with FIG. 9, such a break would be detected by the photoelectric cell 60, which immedi- :ately would transmit a signal to the central commanding station 62 which thereafter would open the electromagnetic water control supply valve 76 (FIG. 6) whereby water ejector nozzle 77 starts to eject water and forms the incision (FIG. 8) and which is on the line of nozzle 154, thereby again defining the safety band 63 to stop the vertex V (not shown in FIG. 8), as previously described. At the same time the movable water ejector nozzle 112' will start to eject Water during such a time until the safety band thereby formed reaches stationary nozzle 77 whereby nozzle 77 stops to eject water since there is a time relay which controls the time of ejection of water of the stationary nozzle 77. The time of water ejection of nozzle 77 is graduated in accordance with the speed of the paper web 8 in direction 135. As soon as movable nozzle 112' starts its movement in direction 143, the restoring of the total width of the paper web is performed, as previously explained.

It will be appreciated that if the watching and commanding station 48 which becomes operative, is one of those near the dry end 33, that a considerable mass of paper will be supplied from the wet end towards its scraper 47 (FIG. 6) all of which mass of paper is to be sent to the sink before the movable nozzle 112 or 112' has pushed back the vertex V and the full web has reached the pertinent station 48.

Since usually the paper collected at the scraper 47 is returned to the supply means of the breast box 2 (FIG. 1a) the concentration of the paper is varied, particularly since the paper scraped off by scraper 47 at the station 48 above considered, has already lost most of its water content. To avoid such an unfavorable concentration, the strong water ejecting nozzle 133 (FIG. 8) receives a water ejecting command from the central commanding station 62 (FIG. la) whereby the water jet 5 will pierce the web 8 and thus a break starts of the type described in connection with FIG. 13, so that only the safety band moves on to the station 48 under consideration whilst the rest of the web is discharged by nozzles 46 (FIG. in from the wire fabric 3. In view of the fact that this paper web .8 is still in pasty form, that is to say contains a major percentage of water content, it does not influence in such a pronounced way the concentration of the cellulose solution.

In case for instance the safety band is ruptured in the air gap 34 or 36 (FIG. 1b), the paper web is completely ruptured and the corresponding starting cell 57 together with cell 146 (as will be later understood) will transmit a signal to the central commanding station 62 (FIG. la), which will start a new starting band 58 by means of nozzle 154 (FIG. 3) which at first remains stationary, and at the same time the'ejector 69 (FIG. 2) ejects air to transport the starting band 58 onto the first felt 10 whereupon photoelectric cell 57 transmits the signal to the central commanding station 62 (FIG. 1a) to stop the air ejection of nozzle 69 and thus the starting. band continues on its path until reaching the pair of press rolls 11 tnd 12 tending to remain adhered to press roll 12 and rise therewith which is avoided by air ejector nozzles 69a and 6% which eject an air jet under both side edges of the starting band 58 thereby separating it from' the surface of roll 12 over nip roll 13', air gap 14 onto the second felt 15. As soon as this is achieved, photoelectric cell 57' stops the air ejection of nozzles 69a and 69b and similarly the starting band 53 will pass through all the stations 48 until reaching first air gap 34 where ejector nozzle 69' Will raise the starting band 58 by means of guiding channel 70 into the upper pair of rollers of the calendaring section 35, thus stopping air ejector nozzle 69 and a similar procedure is repeated with regard to guiding channel 71, bobbin 39 andair ejector nozzle 69 (FIG. 1b). i i

As soon as the last cell 57 (that of FIG. 14) advises of the passage of start band 58 nozzle 154 (FIG. 8) moves in direction of arrow 143 until overpassing position A at which movement nozzle 112' takes over and restores the web 8.

If the safety band 63 is not too wide, the start band 58 may be dispensed with and the safety band 63 may also operate as a start band, in which event start unit 151 becomes unnecessary.

It will be apparent to those skilled in the art that it is not necessary for the movable ejector nozzle 112 to wait with the translatory movement in direction 143 (FIG. until the beginning of the starting or safety band has reached bobbin 39 (FIG. 1b).

All nozzles are preferably interchangeable, for obvious reasons.

Having thus described the invention from the structural and functional viewpoints, the electronic aspect has now to be analyzed.

As has already been previously explained, each of the photoelectric cells should preferably be associated with a standard circuit which enables using the cell to detect either appearance or disappearance of paper. The circuit should furthermore be so framed that slow variations captured by the receiving station will not be transmitted to the central commanding station 62. In FIG. 16 photoelectric cell 59 is again shown and forms part of a voltage divider formed by resistors 159 and 160. In the embodiment shown one end of the resistor 159 is con nected to the positive terminal 161 of the high tension supply source whilst the other end of said resistor 159 is connected to the anode 162 of cell 59. The resistor 160 is connected by one of its ends to cathode 163 whilst its other end is connected to ground terminal 164. The arrangement further comprises a three way two point switch 165 having a first contact arm 166, which may enter in con-tact with either of the fixed contacts 167 and 168; a second contact arm 169 which may enter in contact with either of the fixed contacts 170 and 171 and a third contact arm 172 which may enter in contact with either of the fixed contacts 173 and 174. The contact arms 166, 169 and 172 are ganged. The first contact arm 166 is connected to the high tension end of resistor 159 while the fixed contacts 168 and 170 are connected in parallel to the common point between anode 162 and resistor 159. Contact arm 172 is connected to the ground end of resistor 160 and fixed contacts 171 and 173 are connected in parallel to the common point between cathode 163 and resistor 160. The second contact arm 169 is connected to the grid 175 of a valve 176 through a capacitor 177. Grid 175 is connected to a slider 178 of a potentiometer 179 connected to ground. Valve 176 represents the input stage of an amplifier to be seen later on.

In the position shown of the three way two position switch 165 the resistor 160 is short circuited through contact arm 172, so that only resistor 159 represents the load for the cell 59.

Therefore when the internal resistance of the cell 59 increases (such as by the disappearance of paper), a positive impulse is applied on grid 175 through contact arm 169 and capacitor 177. Alternatively, if the three way two position switch 165 is in the other position, contact arm 166 short-circuits resistor 159 and thus resistor 160 constitutes the load for cell 59, in which event through fixed contact 171, contact arm 169 and capacitor 177 a positive impulse is transmitted to grid 175 when paper appears under the scanned surface of for instance a normally bare press roll. Thus, in one of the positions of switch 165, valve 176 will receive a signal when the paper web 8 disappears from the scanned surface of cell 59' and in the other position of switch .165 such a signal is transmitted when the paper web 8 appears under the scanned surface.

As to the slow variations, which should not be transmitted to the grid 175, a delay time constant is provided by means of the fixed capacitor 177 and the potentiometer 179 providing a RC constant adjustment.

With regard to the electronic circuit arrangement of the restoring equipment and more particularly the arrangement as described in connection with FIGS. 3, 4 and 5, reference will now be made to FIG. 17.

As may be seen, cell 59 has its cathode 163 connected to the negative terminal 164 of the high voltage source. The anode 162 of cell 59 is connected to the input of an amplifier 180 (of which valve 176, see FIG. 16, forms part) the output of which is connected to the input of a first tthyratron stage 181, the details of which will be later on described in connection with FIG. 18. The output of the first thyratron stage 181 is connected to one end of an energizing winding 182 of relay 183. Relay .183 comprises a double switch having a contact arm 1'84 and fixed contacts 185 and 186, and furthermore a single switch having a contact arm 187 and a fixed contact 188. Fixed contact 1 85 is connected to a negative bias source 189, while contact 186 is connected to a positive potential provided by a voltage divider consisting of the resistors 190 and 191. This voltage divider is arranged between the positive terminal 192 and the negative terminal 164 of the high voltage source. Contact arm 1 84 is connected to the input of a second thyratron stage 193, the output of which is connected to one end of an energizing winding 194 of a relay 195 having also a double switch including a contact arm 196 and fixed contacts 197 and 193 and a single switch having a contact arm 199 and a fixed contact 200. Contact arm 196 is connected to the other end of energizing winding 182 of relay 1'83, and fixed contact 197 is connected to positive terminal 192 of the high tension supply source. Fixed contact 193 has no connection.

Returning to relay 183, its contact arm 187 is connected to the terminal 201 of the neutral wire. Contact 188 is connected to one of the ends of an energizing winding 202 of a relay 203, the other end of which is connected to terminal 204 of one of the phases of the alternating current supply source. Relay 203 includes three simple switches of which the first comprises a fixed contact 205 and a contact arm 206, the second comprises a fixed contact 207 and a contact arm 208 and the third comprises a fixed contact 209 and a contact arm 210. The three contact arms 206, 208 and 210 are connected in parallel to terminal 201 of the neutral wire. Fixed contact 205 is connected to one of the ends of the energizing winding 211 of relay 212, the other end of which is connected to terminal 204 of the alternating phase. Relay 212 comprises three single switches each of which comprises contact arms 213, 214 and 215, with respective fixed contacts 216, 217 and 218. Contact arm 213 is connected to the positive terminal 192 of the high voltage supply source, while fixed contact 216 is connected to the energizing winding 194 of relay 195, thereby feeding anode voltage to the thyratron stage 193. Contact arm 214 is connected to terminal 201 of the neutral wire, while fixed contact 217 is connected to one of the ends of energizing winding 219 of the electromagnetic operated check valve 105. The other end of said energizing winding 219 is connected to terminal 204.

Returning now to relay 195, fixed contact 200 is connected to terminal 201 and contact arm 199 is connected to one of the ends of the energizing winding 220 of relay 221, the other end of which is connected to terminal 204. Relay 221 comprises a single switch having a contact arm 222 and a fixed contact 223 of which contact arm 222 is connected simultaneously to the energizing Winding 220 and the contact arm 199. Fixed contact 223 is connected to one of the poles of the synchronous electric motor 113, the other pole of which is connected to terminal 204. Electric motor 113, as has already been described, drives a disk 122 having a peripheral cam 126. Cam 126 operates water supply interrupting microswitch 127 and electric motor stopping microswitch 128.

Microswitch 128 comprises a fixed contact 224 and a cam operated contact 225 connected to terminal 201.

21" Fixed contact 224 is connected to the same pole of the electric motor 113 as fixed contact 223 of relay 221.

The water supply interrupting microswitch 127 has a cam operated contact 226 connected to terminal 2191 and said contact 226 may enter in contact with either of the fixed contacts 227 and 228. Fixed contact :227 is connected to fixed contact 218 of relay 212, the contact arm 215' of which is connected to the junction between winding 211 of relay 212 and fixed contact 2% of relay 203.

Although in FIG. 3 two series of four cutting means units 94, 94, 94", 94a and 25, 95, 95", 95a are shown, in FlG. 17 only one series of three units of cutting means units 94, 94, 94" is shown, whilst unit 94a has been omitted. It will be obvious that the number of units depends on the width of the paper web and can be increased or decreased in accordance with the requirements.

What is more, in FIG. 17 similar elements of unit elements which are used in units 94, 94- and 94", will bear like reference numbers with the corresponding indices.

Returning again to the water supply {interrupting microswitch 127, its fixed contact 228 is connected to one end of an energizing winding 221) of relay 221', the other end of said energizing winding 22% is connected to terminal 204. Relay 221 comprises a single switch having a contact arm .222 and a fixed contact 223'. Contact arm 222' is simultaneously connected to fixed contact 223 of microswitch 127 and to winding 220' of relay 221'. Fixed contact 223' is connected to fixed contact 224 of electric motor stopping microswitch 123 and also to one pole of electric motor 113', the other pole of which is connected to terminal 2%. Cam operated contact 225' is connected to terminal 201. Unit 24 further comprises a relay 229 including an energizing winding 230 one end of which is connected to terminal 2114 and the other end of which is simultaneously connected to fixed contact 267 of relay 203 and to contact arm 231. Relay 229 comprises two single switches of which one comprises contact arm 232 and fixed contact 233 of which contact arm 232 is connected to terminal 291 and fixed contact 232 is connected to one end of energizing winding 219' of the electromagnetically operated check valve 105. Contact arm 231 is in operative relationship with fixed contact 234 connected to fixed contact 227 of water supply interrupting microswitch 127 which furthermore comprises a cam operated contact 226 connected to terminal 291, and further comprises fixed contact 223 controlling the start of electric motor 113 of unit 94", the structural details of which are substantially identical to unit 94 and will therefore not be specifically described, it being sufficient to point out that all the reference numbers of unit 94 are the same as those used in unit 94' but provided with a double index Since unit 94" is the last unit in the arrangement shown in FIG. 17, fixed contact 228" of Water supply interrupting microswitch 127 remains unconnected and could be used to control the start of the electric motor of a next unit, for instance unit 94a (see FIG. 3).

In view of the functional description previously made in relationship to the mechanical arrangement, anybody skilled in the art will already visualize the functional arrangement from the electronic viewpoint.

Assuming that cell 59 detects a break and transmits f a signal, as described in relationship with FIG. 10, said signal is amplified by amplifier 186 and its output triggers the first thyratron stage 181, the output of which energizes relay generally indicated at 183 from positive terminal 192 through fixed contact 197 and contact arm 1% of relay 195 which at this moment is tie-energized. .Thus energized relay .183 performs two functions simultaneously, of which one consists in energizing relay 203 through contact arm 187 and fixed contact 188. Upon energizing relay 2% the three single switches are closed and thereby energizing relays 212, 229 and 229" which by closing contacts 214-217, 232-233 and 232"-233" open the electromagnetically operated check valves 105, and 1115", respectively, whereby the respective nozzles 112 (FIG. 3) start to eject Water. As Will be seen later on, when analyzing FIG. 19, the photoelectric cell 59 does not only command the simultaneous ejection of water through nozzles 112, but also through all the nozzles 75 and 77 (see FIG. 6).

The energization of relay 183 further carries out the commutation of the input of the second thyratron stage 193 from a negative blocking potential terminal 189 to a positive potential provided by the voltage divider 190- 191, thereby producing the triggering of the second thyratron stage 193 which energizes relay which provides two functions. The first function consisting in interrupting the positive supply from terminal 192 which de-energizes relay 183, whereby contact arm 187 is spaced apart from fixed contact 188, and thus de energizing relay 2&3, whereby its contact sets 2tl5-21l6, Ztl72tl8 and 20921(l are opened. In spite of the opening of contact set 2tl526, relay 212 remains energized due to its locking circuit formed by the contact arm 215, fixed contact 218, fixed contact 227, cam operated contact 226 of microswitch 127 and terminal 2111, so that valve 105 remains open and water keeps on ejecting through nozzles 112.

Returning now to relay 195, the engagement of contact arm 199 with fixed contact 2% energizes relay 221 closing its contact arm 222 with fixed contact 223, thereby starting motor 113. Thus it will be understood, that the ejection of water through nozzles 112 and the start of electric motor 113 is simultaneous; but if desired, a time constant circuit may be included in the circuit of the second thyratron stage 193 in order to delay the starting of the motor 113 with regard to the water ejection, as will be better understood when reference is made to FIG. 18, in order to achieve distance t, see FIG. 10, as previously explained.

When the relay 133 releases due to termination of the photocell signal and blocking of thyratron stage 18 1, the thyratron stage 193 is also blocked by negative potential from source 189 now standing on relay contact 184. As a consequence, relay 195 also releases, opening the contacts 199 and 2611; nevertheless the relay 221 and motor 113 remain energized through closed contacts 224- and 225 of the electric motor limit microswitch 128. Although the relay 195 is now released with positive potential standing on the relay contact 196, the thyratron stage 1511 does not trigger due to termination of the photocell signal at 59, and the relay 183 consequently remains deenergized. For further assuring deenergization of the relay 1195, the anode supply to the thyratron stage 193 is interrupted by the separation of the movable contact 213 from fixed contact 216 of relay 212, this relay being deenergized when the contact arm 226 of the water supply interrupting microswitch 127 opens at fixed contact 227.

Returning now to cam 126, as soon as the latter operates the water supply interrupting microswitch 127, the cam operated contact 226 is spaced apart fromfixed contact 227 and contacts the fixed contact 228. During he opening of contacts 227 and 226, the locking circuit of relay 212 is interrupted and relay 212 is being deenergized whereby due to the opening of contacts 214 and 217 the water supply to nozzle 112 is interrupted by check valve .195. As soon as cam 126 has passed through microswitch 127, contacts 226 and 227 are reclosed but relay 212 cannot be re-energized, due to the open position of contacts 213 and 215 of the locking circuit previously described. At this moment nozzle 112 is in position A see FIG. 3. It is furthermore known that nozzle 112 has to return to its start position (that is to say point A, FIG. 3) without ejecting any water, to which end motor 113 has to keep on running

Claims (1)

1. 6. IN THE MAUFACTURE OF A CONTINUOUS PAPER WEB, THE METHOD OF RESTORING THE WIDTH OF THE WEB AND MAINTAINING ITS CONTINUITY UPON INTITATION OF A WEB BREAK WHICH COMPRISES CUTTING A SAFETY BAND PARALLEL ALONG THE SIDE OF THE WEB OPPOSITE THE BREAKING SIDE, CONTINUING THE CUT FROM SAID SAFETY BAND DIAGONALLY ACROSS THE WEB SO AS TO SEVER AND ISOLATE THE BREAK SECTION AND FORMING AN INTENTIONAL

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