US 3346159 A
Description (OCR text may contain errors)
Oct. 10, 1967 K. WINKLER 3,346,159
APPARATUS FOR, THREADING A WEB INTO A PLANT FOR PROCESSING SAID WEB Filed Oct. 1, 1965 INVENTOR, KARL Ll/MKLER United States Patent 3,346,159 APPARATUS FOR THREADING A WEB INTO A PLANT FOR PROCESSING SAID WEB Karl Winkler, Linz, Austria, assignor to Vereinigte Osterreichische Eisenund Stahlwerke Aktiengesellschaft, Linz, Austria Filed Oct. 1, 1965, Ser. No. 492,017 Claims priority, application Austria, Oct. 12, 1964, A 8,648/64 8 Claims. (Cl. 226-92) This invention relates to an apparatus for threading a web into a plant for processing said web.
In plants for a continuous processing of web stock, such as metal or plastics material webs, roll feeders or the like are provided in most cases between the uncoiler and the take-up device. These roll feeders serve for moving the web and in most cases also for threading a new web into the plant. In some cases, such roll feeders cannot be provided, at least along part of the path, because a damage of the web surface by contact with the rolls must be avoided. For instance, roll feeders cannot be provided after a coating, particularly an enamel coating, has been deposited on the web, because the resulting web has a most sensitive surface until the coating has been set in a drying oven, which is in many cases very long. During the operation, the web is fed through the drying oven or the like by means of roll feeders which succeed this oven, or by the take-up device. It is difiicult to thread the web as far as to the feeder which acts on the finished web to advance the same. For this purpose, a threading apparatus has already been disclosed which consists of two endless ropes, which are disposed on opposite sides of the .path of the Web and in which a clamp for the leading end of the web is secured to each of said ropes. To ensure a uniform coating or other processing of the web, the-movement of the web must be uniform. For this reason, theclamping of the leading end of the web to the two pulling ropes must not be effected when the web is stopped but when it is moving. At the. take-up end of the plant, more time is available for feeding the leading end of the web to the take-up device because the web has then passed through a usual roll feeder, and a storage loop can be formed between this feeder and the take-up device. The known threading apparatus has the disadvantage that the leading end of the web must be clamped by hand to the pulling ropes. This operation requires two workers, who walk along the web and must take care to complete the clamping operation before the entrance to the drying oven. This operation requires a certain time so that a certain minimum space is needed before the entrance to the drying oven and adds to the overall length of the installation. When the web is subsequently pulled through the feeders, the means for fixing the jaw-type clamps to the pulling ropes, which are not guided between the reversing pulleys, may give rise to difliculties. Besides, the web may sag in the middle or may move up and down during the threading so that the deposited enamel coat ing or the like, which has not yet set, coalesces at some point and the coating becomes irregular. Finally, a change in the width of the web requires an exchange of the jawtype or other clamps. This results in a loss of time.
It is an object of the invention to eliminate all these disadvantages. The invention is based on a threading device which comprises longitudinal pulling means, which are disposed on opposite sides of the path of the web and preferably endless, and clamp means, which are secured to said pulling means and grip the end of the web, and is essentially characterized in that the clamp means comprise two superimposed rolls, which are connected by two common bearing brackets to the two longitudinal pulling means, consisting of track-guided chains, at least one of said rolls being eccentrically mounted to form an eccentric clamp, and carrying a crank arm or the like, a stationary run-up cam being provided for a pivotal movement of the crank arm or the like in the clamping sense, and a further run-up cam being provided, if desired, at the takeup end of the plant and serving to effect a ivotal movement of the crank arm in the opposite sense, the chain driving means being adapted to be started automatically when the leading end of the web to be threaded passes through between the rolls, and to be stopped automatically when this leading end of the web reaches the take-up end of the plant. When the chain driving means have been started, the incoming web end is then automatically clamped with the aid of the run-up cams so that any need for manual work is eliminated as well as the space previously required for manipulation before the drying oven or the like. This results in a reduction of the overall length of the plant. The clamping rolls reliably grip the web throughout its width, and the track-guided chains ensure that the web is threaded without vibration. As a result, the uniformity of the coating is no longer adversely affected. As the laterally disposed jaw-type clamps have been replaced by clamping rolls which extend throughout the width of the web, it is possible to clamp stock of dilferent widths without any need for changing the threading apparatus.
It would be possible to provide a centric mounting for one of the two rolls and an eccentric mounting for the other. It is more desirable, however, if both rolls are eccentrically mounted and coupled by a spur gear train mounted on their journals so that a rotation of one of the rolls under the action of the crank arm and the run-up cam results positively in a rotation of the second roll to perform the clamping movement. To ensure a uniform clamping of the leading end of the web and particularly to prevent an automatic opening of the eccentric clamp by the tension which is applied during threading the Web, it is a development of the invention to space the axes of the roll journals rearwardly from the roll axes with respect to the pulling direction and to arrange the rolls symmetrically with respect to the plane of the path of the web. The longitudinal axes of the pulling course of the chains are also in the plane of the path of the web so that torques are avoided which could cause a buckling of the chain.
A particularly suitable design will be obtained if the chains consist of side bar chains having rollers on the pins and guided in laterally open channel members, each directed through the path of the web are provided in known manner for starting and stopping the chain driving means and comprise photoelectric cells for closing or interrupting the drive circuit when the light ray is interrupted by the arriving band end. At the inlet end, these light barriers are disposed slightly behind the pair of clamping rollers in the initial position and before the runup cam and at the take-up end of the plant they are provided behind the run-up cam so that the chain driving means are started as soon as the leading end of the web has passed through between the rolls and the chain driving means are stopped as soon as the clamping rolls have opened. It is not essential to provide at the trailing end of the plant a run-up cam for opening the clamping rolls. Alternatively, the resulting eccentric clamp may be effected by a rotation of one roll with the aid of an inserted crank handle.
An illustrative embodiment of the invention is shown by way of example on the drawing, in which FIGS. 1 and 2 are sectional views taken on line I-I of FIG. 2 transversely to the path of the web, and
FIG. 2 is a transverse sectional view taken on through the rolls on line II-II of FIG. 1.
In a plant for processing web stock, such as a varnishing plant for manufacturing insulated sheet metal elements, endless longitudinal pulling means are provided on opposite sides of the path of the web in that portion thereof which contains no roll feeders, for instance adjacent to the drying oven. These longitudinal pulling means comprise side bar chains 2, which are guided in laterally open channel members 1. The chains comprise rollers 3 on pins 4. An angle member 5 is secured to each chain and carries an upright bearing bracket 6. Two rolls 7 are eccentrically mounted in the two opposed bearing brackets and are coupled by a spur gear train 9 mounted on their journals 8, 8a. One journal 8 of the upper roll carries a crank arm 10 provided with a roller 10a. A stationary run-up cam 11a is provided for engagement by the roller 10a of the crank arm 10. If the chain 2 and the pair of rollers 7 move in the direction which is indicated by the arrow 12 in FIG. 2, the crank arm 10 is pivotally moved downwardly so that the rolls 7 are rotated and owing to their eccentric mounting approach each other and clamp the web material 13 between them. The axes of the journals 8, 8a are rearwardly spaced from the roll axes proper with respect to the pulling direction and the rolls 7 are symmetrical with respect to the plane which is defined by the web 13. A light barrier 14, 15 serves for starting the chain driving means.
The processed web material, which has been coated or provided with an enamel layer so that it has a highly sensitive surface before it has set, is advanced by means of a roll feeder, which is disposed before the coating station. The leading end of the web enters between the two rolls 7. As soon as the leading end of the web 13 has interrupted the light ray of the light barrier, the photoelectric cell 15 starts the chain driving means. It is obvious that the chain driving means corresponds to the velocity of the web. The movement of the chain causes by means of the run-up cam 11 and the crank arm 10 a closing of the eccentric clamp which consists of the two rolls 7 and these rolls pull the web through the succeeding part of the plant, for instance, the drying oven. A roll feeder is provided at the take-up end of the plant and serves for advancing the web when it has passed through said feeder. Another light barrier for stopping the chain driving means is disposed behind this feeder. The clamp can now be opened by means of a crank handle, which can be fitted on the square 16. Then the web can be fed to the take-up device. Alternatively, a second run-up cam may be provided before the light barrier to effect an automatic opening of the clamp. When it is desired to insert a new web, the clamping apparatus is returned to its starting position with the aid of the endless side bar chain.
What is claimed is:
1. Apparatus for threading a web into a plant, for moving said web in a predetermined direction along a predetermined path and for processing said web during such movement, said apparatus comprising two chain tracks extending on opposite sides of said path in the longitudinal direction thereof, two chains movable along said path in the direction of movement of said web, each of said chains being guided by one of said tracks, two bearing brackets, each of said bearing brackets being secured to one of said chains, two superimposed clamping rolls having opposite ends mounted in said bearing brackets, one of said rolls being eccentrically mounted and carrying a radial projection, said chains being stopped after a predetermined movement of said rolls along said path, a stationary run-up cam mounted in the path of said radial projection for engagement thereby so as to move said eccentrically mounted roll against the other roll, and starting means for automatically starting movement of said chains in response to the passage of the leading end of said web between said rolls.
2. Apparatus as set forth in claim 1, in which said chains are endless.
3. Apparatus as set forth in claim 1, in which said radial projection is a crank arm.
4. Apparatus as set forth in claim 1, which comprises a second stationary run-up cam succeeding the first-mentioned run-up cam in said predetermined direction and mounted in the path of said radial projection for engagement thereby so as to move said eccentrically mounted roll away from the other roll.
5. Apparatus as set forth in claim 1, in which the other roll is also eccentrically mounted and said rolls are provided with journals carrying a spur gear train for coupling said rolls.
6. Apparatus as set forth in claim 5, in which the axes of said journals are rearwardly offset from the axes of said rolls with respect to said predetermined direction, said path defines a plane, and said rolls are symmetrically disposed with respect to said plane.
7. Apparatus as set forth in claim 1, in which said path defines a plane, said chains are endless and each chain has a forward course having a longitudinal axis lying in said plane.
8. Apparatus as set forth in claim 7, in which said chains are side bar chains comprising pins and rollers mounted on said pins, said tracks are laterally open channel members, each chain carries a depending angle member, said bearing brackets are upright and each of said brackets is secured to one of said angle members.
References Cited FOREIGN PATENTS 252,560 6/1964 Australia. 382,439 11/ 1964- Switzerland.
M. HENSON WOOD, JR., Primary Examiner.
R. A. SCI-IACHER, Assistant Examiner.