US3085346A

US3085346A - Threading web material

Info

Publication number: US3085346A
Application number: US836221A
Authority: US
Inventors: Allander Claes; Lanne Bengt; Wallin Sven
Original assignee: Svenska Flaktfabriken AB
Current assignee: Svenska Flaktfabriken AB
Priority date: 1958-12-04
Filing date: 1959-08-26
Publication date: 1963-04-16
Anticipated expiration: 1980-04-16
Also published as: CA639680A; BE579034A; GB912485A

Description

C. ALLANDER ETAL THREADING WEB MATERIAL 2 Sheets-Sheet 1 INVENTORSI CLAES ALLANDER BENGT LANNE svEN wALLlN BY ATTYS.

IIV

April 16, 11963 Filed Aug. 26, 1959 April 16, 1963 3,085,346

c. ALLANDER ETAL Filed'Aug. 26 1959 THREADING WEB MATERIAL 2 Sheets-Sheet 2 INVENTOR SI CLAES ALLANDER BENGT LANNE SVEN WALLIN ATTYS.

United States Patent O THREADHNG WEB MATERIAL Claes Allander, Scdra Angby, and Bengt Laune and Sven Wallin, lonkoping, Sweden, assignors to Aktiebolaget Svenska Flalrtt'ahriken, Stockholm, Sweden Filed Ang. 26, 1959, Ser. No. 836,221 Claims priority, application Sweden Dec. 4, 1953 5 Claims. (Ci. 342-46) The present invention. relates to a method and apparatus for threading, i.e. guiding and transporting the leading end of a web, particularly a web of wet material with low mechanical strength, which is to be transported air-borne in one or more runs through a drier or similar apparatus by means of a treating medium being blown against the web.

In all treatment of web materials in apparatus of the above mentioned type it has always been a diicult problem to guide and transport the leading end of the web. It has previously been customary at the turning points of the web between the different runs to manually transfer the leading end of the web between the transport elements of the different passages. Besides being time-consuming this manual procedure is especially ditlicult to carry out when treating a wet material with low mechanical strength, for instance cellulose pulp. The lower transport speed necessary in the manual threading procedure .when treating cellulose pulp also requires a certain complicated adjustment in the preceding Iwet section of the treatment apparatus. Even greater diiiculties for the threading exist in the driers developed in recent times which are made without conveyors and where the web is carried completely air-borne, since it is necessary to forcefully guide the leading end of the web continuously along its entire path of transportation and thus not only at its turning points. For conserving space the runs of the web must be arranged at such a relative distance that a manual forceful guiding of the leading end of the web between the turning points is quite impossible. Furthermore, devices are known which provide an automatic threading by inserting the leading end of the web between' two endless conveyors running along one side of the web, which conveyors carry the web through the drier. In larger driers, where the web is carried in a large number of runs through the apparatus, however, such an arrangement is too complicated and costly.

The present invention which relates to a new method and apparatus for threading without using mechanical transporting means is characterized in that the leading end of the web is kept stretched in the transport direction of the web and is prevented from fluttering by being connected with a threader having an air-borne or floating pilot inserted in ,advance of the web in the `apparatus the pilot being made of light material having a great area relative to weight and having a substantially plain surface for supporting and transporting the pilot by the aid of the upward and forward directed power components respectively of said treating medium.

The pilot used may either be attached directly to the leading end of the web or by means of one or several ropes or bands. When carrying out the new method it is advisable that the web in a known way be torn or cut olf at its leading end from one edge of the web diagonally across the web to its opposite edge, so that a long and narrow ap is formed and the pilot connected with the mentioned flap. In carrying out the method, a pilot consisting of a dried piece of the web may suitably be used or the pilot may consist of a Substantially plain sheet of another material with suitable connecting means for the connection of the pilot with the leading end of the web. The pilot or the threader may also in accordance with a suitable method be made of two layers of material "ice in the form of a backwards open sack, which may be divided by longitudinal seams into several units.

The invention also relates to an apparatus for the performance of the method. Such an apparatus is characterized in that the connecting means consist of an angular double folded band, the Shanks of which -by inlaid springs are kept pressed against each other and a relatively long rope, or other similar connecting means attached between the band and the pilot, which rope before the threading is kept coiled in a ready position in front of the apparatus in a revolvable magazine. A guiding :means or trumpets is directed diagonally towards the straight edge of the leading end of the web and is furnished with an inlaid angular bar, which by the insertion of the band opens the Shanks and keeps them open until they pass the end of the enclosed bar, where said bar encloses the edge of the web at this point they are released and grip around the edge of said web, whereby the leading part of the web thereafter is kept stretched by the threader and is carried through the apparatus.

The invention will now be described more -fully with suitable reference to the accompanying drawings, which show one form of an apparatus for performing the method, in which:

FIG. 1 shows a longitudinal section of a drier furnished with a threading apparatus according to the invention.

FIG. 2 is a plan View of a part of the threading apparatus;

FIGS. 3 to 5 inclusive are details in fragmentary perspective of a double folded band used for connecting the pilot to the web;

FIG. 6 is a perspeitive View of the guiding means or trumpet for engaging the threader with the web;

FIG. 7 is a perspective View of the pilot of the threader;

FIG. 8 is a perspective view of a modified spring detail of the connecting means; and

FIG. 9 is a perspective view of a modied pilot.

In the drawings a web-like material 1, `after having passed a pair of rolls 2 which constitute the last part of a forming and pressing section, is brought through an opening 3a into a drier 3 or other treating apparatus, where the web-like material is transported forward in one or more runs 4a, 4b etc. over a number of rolls 5a, 5b etc. indicates an outlet opening for the treated web-like material. The threader for the drier 3 has a pilot 6 made with a substantially plain surface for supporting and transporting the pilot with the -aid of the upwardly and forwardly directed power components of the treating medium being supplied -for drying the web. In the embodiment shown in FIGS. 1 to 7 the pilot 6 consists of a piece of an already dried web. As shown in FIG. 9, the pilot 6a may also be made of two layers 21 and 22 of material in the form of a backwardly open sack, which by longitudinal seams 23 is divided into several straight or tapered units. A rope 7 is attached at the rear end of the pilot 6 or 6a, the other end of said rope being connected with the leading end of the web 1, which in the case shown is shaped as a long and narrow flap la, formed in a known way by tearing ot the leading end of the web from one edge of the web diagonally across the web over to its opposite edge. The rope 7 is attached to the web by an angular double-folded band 8 (see FIGS. 3 and 4), the

shanks

8a and 8b of which are pressed against each other by means of inlaid springs 9. The spring means 9 may consist of triangular elements 18a and 18h (see FIG, 5) inlaid in the Shanks 8a and 8b, or may constitute rectangular elements '19a and 1911 (see FIG. 8) inlaid in the

shanks

8a and 8b. This band before the threading is kept coiled in a ready position in a revolvable magazine lll, placed in front of the drier 3. A stationary plain table 151 supports aossas the web during the threading. In the illustrated ernbodiment, the table is constructed like a box with perforated top wall 24 for supplying a gaseous medium to reduce the friction between the wet web and the table 11. At one side of the table 11 a guiding means or trumpet 12 for the band 8 is directed diagonally towards the straight edge 1b of the flap of the web and is furnished with an inlaid angular rail 13y (see FIGS. 2 and 6), which rail during the insertion of the band at the end 13b engages between the

shanks

8a and 8b of the band to open them, the central portion of the rail 13 keeping the Shanks open until they, at the end l13m of the inlaid rail where said rail embraces the edge 1b of the web, are released and grip around the straight edge 11b of the web. The liap of the material will in this way be stretched by the pilot and automatically will be transported through the drier. The invention is especially intended for driers with an airborne web, but is of course also applicable to driers provided with mechanical conveyors for transporting and supporting the web.

What we claim is:

1. A method for threadingy through a treating apparatus the leading end of a sheet of wet web material with low tensile strength, wherein the web material is transported air-borne in at least one run by means of a treating medium impinged `against the web in an upward and forward direction, comprising the steps of providing a light-weight pilot sheet of greater tensile strength than said web and having a substantially plain surface of sufficient area relative to weight as to also be air-borne and A.

moved forward by said treating-medium, providing on said pilot a foldable band extending rearwardly from one side of said pilot, connecting said pilot to the leading end of the web material by folding said band over one edge of the web material, inserting said pilot into the treating apparatus in advance of the web material, and supporting and transporting said pilot through the drier by the upwardly and forwardly directed components of the treating medium to support the pilot and stretch the forward end of the sheet of web materaial in the direction of travel through the apparatus to prevent fluttering and tearing of the forward end of the wet web material of low tensile strength, the pilot and the web material sheet being transported together air-borne by the treating medium with the pilot sheet entraining the forward end of the web sheet. f

2. A device for threading the leading end of a sheet of web material of low tensile strength through a treating apparatus having guiding rolls providing horizontal runs therebetween and means forming jets of treating medium underlying said runs to impinge against the underside of the web in an upward and forward direction to move the web forward air-borne along said runs, said device comprising a pilot of a material having greater strength than said web material and having a body of sheet form with a plain lower surface of sufficient area relative to weight as also to be floatingly supported and moved forward by the upwardly and forwardly directed components of the impinging jets of said treating medium, and means connecting said pilot with the leading end of the web, said pilot being formed of two superposed sheetsheld together by at least two longitudinal seams forming i at least one sack-like space opening to the rear of the pilot.

3. A device for threading the leading end of a sheet of web material of low `tensile strength through a treating apparatus having guiding rolls providing horizontal runs therebetween and means forming jets of treating medium underlying said runs to impinge against the underside of the web in an upward and forward direction to move the web forward air-'borne along said runs, said deviee cornprising a pilot of a material having greater strength than said web material and having a body of sheet lform with a plain -lower surf-ace of suiiicient area relative to weight as also to be -floatingly supported and moved forward by the Iupwardly and forwardly directed components of the impinging jets of said treating medium, and means connecting said pilot with the leading end of the web, said pilot including a band extending rearwardly from the body thereof, and edge-engaging clip means carried by said band for fastening the same to the side edge behind Y paratus having guiding rolls providing horizontal runs therebetween and means forming jets of treating medium underlying said runs to impinge against the underside of the web in an upward and `forward direction to move the web forward air-borne along said runs, said device comprising la pilot of a material having greater strength than said web material and having a -body of sheet for-m with a plain lower `surface of sufficient area relative to weight Ias also to be lioatingly ysupported and moved forward by the upwardly and forwardly directed components of the impinging jets of said treating medium, and means conneeting said pilot with lthe leading end of the web, said sheet of web material being formed to have a tapered leading edge extending from one side edge thereof, and `connecting means including a relatively long ropelike element extending rearwardly from said pilot and terminating rearwardly in a double-folded angular band having spring means Itherein operable to press the shank-s of Ithe band toward each other to form an elongatedjaw-like member adapted to grasp one edge of the long side of the flap of the web.

5. Apparatus as set forth in claim 4 which fur-ther iucludes a revolvable magazine adjacent the -feed end of said treating apparatus, said band in operative position being coiledin said magazine, and guide means including Y an angular rail formed to open the Shanks of the doublefolded band and position them to grasp the edge of the flap of -the -web upon advance of the latter into the treating apparatus.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A METHOD FOR THREADING THROUGH A TREATING APPARATUS THE LEADING END OF A SHEET OF WET WEB MATERIAL WITH LOW TENSILE STRENGTH, WHEREIN THE WEB MATERIAL IS TRANSPORTED AIR-BORNE IN AT LEAST ONE RUN BY MEANS OF A TREATING MEDIUM IMPINGED AGAINST THE WEB IN AN UPWARD AND FORWARD DIRECTION, COMPRISING THE STEPS OF PROVIDING A LIGHT-WEIGHT PILOT SHEET OF GREATER TENSILE STRENGTH THAN SAID WEB AND HAVING A SUBSTANTIALLY PLAIN SURFACE OF SUFFICIENT AREA RELATIVE TO WEIGHT AS TO ALSO BE AIR-BORNE AND MOVED FORWARD BY SAID TREATING MEDIUM, PROVIDING ON SAID PILOT A FOLDABLE BAND EXTENDING REARWARDLY FROM ONE SIDE OF SAID PILOT, CONNECTING SAID PILOT TO THE LEADING END OF THE WEB MATERIAL BY FOLDING SAID BAND OVER ONE EDGE OF THE WEB MATERIAL, INSERTING SAID PILOT INTO THE TREATING APPARATUS IN ADVANCE OF THE WEB MATERIAL, AND SUPPORTING AND TRANSPORTING SAID PILOT THROUGH THE DRIER BY THE UPWARDLY AND FORWARDLY DIRECTED COMPONENTS OF THE TREATING MEDIUM TO SUPPORT THE PILOT AND STRETCH THE FORWARD END OF THE SHEET OF WEB MATERIAL IN THE DIRECTION OF TRAVEL THROUGH THE APPARATUS TO PREVENT FLUTTERING AND TEARING OF THE FORWARD END OF THE WET WEB MATERIAL OF LOW TENSILE STRENGTH, THE PILOT AND THE WEB MATERIAL SHEET BEING TRANSPORTED TOGETHER AIR-BORNE BY THE TREATING MEDIUM WITH THE PILOT SHEET ENTRAINING THE FORWARD END OF THE WEB SHEET.