US 1958692 A
Description (OCR text may contain errors)
May 15, 1934.
J. A. BESAL ET AL 1,958,692
SHEET HANDLING MACHINE Filed Sept. 11. 1930 MIA/@11 ATTORNEY Patented May 15, 1934 SHEET HANDLING MACHINE Joseph A. Besal, Chicago, and Clifford E. Ives,
Ill., assignors to United States Gypsum Company, Chicago, Ill., a corporation of Illinois Application September 11, 1930, Serial No. 481,236
This invention relates to sheet handling apparatus and has reference more particularly to apparatus for tensioning and guiding sheet material, such as paper, into machinery which utilizes same, such as a plasterboard machine.
In the manufacture of plaster board, wallboard and the like, it is customary to interpose a layer of cementitious material, such as gypsum base composition, between an upper and lower sheet of heavy paper. The cementitious material sets to solid form and forms a board-like sheet which is cut up into suitable lengths and dried. The strips of paper for forming the cover sheets of the board are usually supplied in the form of rolls, which are large and heavy and are usually supported upon shafts. It sometimes happens that the center of the roll will telescope relative to the outer layers thereof, and thus cause the paper strip to work oil to one side of the machine and form imperfect board. It is also necessary to apply a certain amount of tension to the paper strips being fed into the plasterboard machine so that proper action of the paper is obtained.
An object of this invention, therefore, is to provide a device for properly steering the paper in the plasterboard machine when telescoping of a roll takes place, or when the roll works over to one side of the board machine.
Another object of the invention is to provide a device for properly tensioning the strips of paper as they pass into the board machine: also to improve sheet handling apparatus in other respects hereinafter specified and claimed.
Reference is to be had to the accompanying drawing forming a part of this specification, in which Fig. 1 is a side elevation of the feed end of a board machine showing our improved devices in place,
Fig. 2 is a plan view of the guiding and tensioning device,
Fig. 3 is an elevation of the tensioning device on a large scale, and
Fig. 4 is a sectional view through the tensioning device, taken on line 44 of Fig. 3.
The board machine ordinarily consists of a table 10 over which passes a continuous strip of lower cover sheet 11 and a continuous strip of upper cover sheet 12. Plastic material, such as ypsum base composition mixed with water, is caused to flow onto the lower cover sheet from any suitable supply chute or mixer 14 just before the upper cover sheet 12 passes around a rotatably mounted master roll 15. The master roll 15 presses the plastic material out fiat between the two cover sheets and as the board passes forwardly on the board machine, the gypsum sets to solid form and forms the plasterboard which is cut up into pieces of suitable length and then dried to prepare it for market.
The upper cover strip 12 is usually supplied in the form of a roll 16, which is rotatabiy mounted upon a shaft 1'1, the latter being supported in suitable bearing brackets 18. The lower cover sheet 11 is also supplied in the form of a roll 19 which is rotatably supported upon a shaft 20, the latter being rotatabiy and removably supported upon a bearing bracket 21. Any number of intermediate guide rollers 22 may be provided in contact with the paper cover strips 11 and 12 to cause them to follow the desired path.
It often happens. that the rolls 16 and 19, which are quite heavy. loosen up at the center due to difference in diameter between the shafts l7 and 20 and the interior of the rolls. The result of this loosening is that the rolls may Work off to one side and become-telescoping, in which case the paper strips are apt to be moved to one side as they pass along the board machine, thus causing imperfect board to be made.
Our improved guiding and tensioning device, is therefore interposed between each of the rolls l6 and 19 and the board machine. This device consists in a U-shaped framework or tension bracket having a base member 23 and upright arms 24. The base member 23 is provided at its center with a pivot bolt 24a which has an enlarged head 25 adapted to be rotatabiy received in a similarly shaped recess formed in the upper surface of the base member 23. The bolt 24a passes through a supporting frame member 26 and is secured thereto by means of a nut 27 or'other suitable device. The frame member 26 is confined between a washer 26a and an annular shoulder 26b provided on the bolt 24a. The tension bars 28, 29 and 30 are rigidly secured between the upstanding arms 24. being retained at one end in similarly shaped recesses 31, and at the other end they are retained by bolts 32 extending through one of the upstanding arms 24, being tapped into the ends of said tension bars. The tension bars are preferably semi-circular where said bars contact with the strip of paper and the bars may be provided with fiat surfaces 33 where no contact with the paper is made. These fiat surfaces 33 fitting in the recesses 31 serve to prevent rotation of said tension bars due to the friction of the moving strip of paper. The three tension bars are arranged in the form of a triangle, the bars 28 and 30 being lower-most and the bar 29 being at the top or apex of the tri angle. The paper is threaded through the tension barsas shown in Fig. 4.
A pair of guides 34 is associated with the table 10, one guide being mounted in sliding contact with each edge of the paper strips 11 and 12. Connecting plates 36 are secured to the guides 34 so as to maintain said guides in spaced, parallel relation with the distance between said guides equal to the width of the paper strips 11 and 12. The rear-most ends of guides 34 are bent outwardly to form guiding flanges 3'? which receive the incoming strip of paper and prevent any tearing thereof. The tension bracket supporting the tension bars 28, 29 and 30, is free to swing about pivot 24a in a plane parallel to the movement of the paper as the rolls of paper 16 and 19 telescope in and out during the unwinding operation. The action of the tension bars is to accurately feed the strip of paper 35 between the guide bars 34, regardless of the position of the rolls of paper. The general action of the device is best seen in Fig. 2 where dot and dash lines show a second position of the cooperating parts. The effectiveness of our pivoted device is apparent when it is taken into consideration that if the ends of the strips of paper are displaced transversely without severing and the longitudinal edges are substantially maintained in parallelism, the paper must necessarily be allowed to buckle obliquely intermediate its ends; and as the ends are moved transversely of one another, the buckled portion changes its transverse direction with relation to the longitudinal edges of the paper from one oblique direction to another oblique direction.
In operation, the cover sheets 11 and 12 feed from rolls 19 and 16 respectively around tension bars 28, 29 and 30 and onto the table 10 of the board machine. The plastic core material flows from the chute 14 onto the lower sheet 11. The upper strip of paper feeds from roll 16 around similar tension bars 28, 29 and 30, around roller 22 and around the master roll 15 so as to be applied to the upper part of the plastic material 13 which is spread out evenly by said master roll. The tension bars 28, 29 and 30 are rigidly mounted on the tension bracket which is pivotally mounted to swing about pivot bolt 24a so as to insure that the paper strip is delivered substantially correctly in position between the longitudinal guides 34 regardless of the position of the rolls 16 and 19 due to telescoping 01' said rolls.
We will state in conclusion, that while the illustrated example constitutes a practical embodiment of our invention, we do not wish to limit ourselves precisely to these details, since manifestly, the same may be considerably varied without departing from the spirit of the invention as defined in the appended claims.
Having thus described our invention, we claim as new and desire to secure by Letters Patent:
1. A tensioning and guiding device for moving strips of sheet material, which comprises a tension element pivotally mounted to swing in a plane parallel to the plane of the strip material, a plurality of rigidly mounted, substantially parallel, tension bars associated with said element, said tension bars being adapted to receive a strip of sheet material from a roll, and guides for receiving of material from said tension bars.
2. In a sheet feed device, means for supporting a roll of sheet material to be unwound and passed continuously to a discharge point, a plurality of rigidly mounted tension elements, at least one of which is positioned out of the plane of said sheet, adapted to receive the sheet passing around said elements to increase the tension in said sheet, and pivotally mounted supporting means for said tension element adapted to permit said tension elements to swing freely in a plane parallel to the movement of the sheet, as the roll of sheet material changes its position and telescopes.
3. In a plasterboard machine, means for continuously unwinding a top strip and bottom strip from rolls of paper, rigidly mounted tensioning devices adjacent a strip of paper adapted to increase the tension in said paper, supporting means for said tensioning element, said supporting means being pivotally mounted so as to swing freely in a plane parallel to the plane of movement of the strip of paper as said strip 01' paper unwinds from said roll, and guide means for receiving said strip of paper after said strip leaves said tensioning element.
4. In a plasterboard machine, means for rotatably supporting a roll of paper to be unwound and continuously moved to form the plasterboard, a pivotally mounted tension bracket positioned to swing about a vertical axis adjacent said moving strip of paper, tension bars rigidly secured to said tension bracket and arranged to permit said strip to be threaded around said tension bars, and guides adjacent the edges of said moving strip after said strip leaves said tensioning bars, said tension bracket and bars being adapted to swing freely as the position of said roll changes longitudinally on its axis.
5. In a device for guiding strip material in a predetermined path, means swingably mounted about a vertical axis in the path of said strip material and supporting a plurality of rigid elements over which the strip material is threaded, the swingably mounted means deflecting a portion of the strip material substantially vertically out of the plane of movement thereof and swinging freely in an are as said deflected portion assumes an oblique direction with respect to the direction of movement of the strip material when one end of the material is displaced transversely with relation to the other end, whereby the longitudinal edges 01 the material are maintained in parallelism.
6. The combination in a device for guiding a strip of sheet material, of means pivotal about a vertical axis in the path of the strip and supporting a plurality of rigid elements over which the strip is threaded, and means for guiding one end of the strip in a fixed path, said pivotal means swinging freely in an are as the other end of the material is displaced transversely with relation to the first mentioned end.
7. In a device for maintaining a moving strip of material in a desired path, means swingably mounted in the path of said strip about an axis vertical to the plane of movement of the strip and supporting a plurality of rigid elements over which the strip is threaded, and means for consistently maintaining one end of the strip in a fixed path, said swingably mounted means deflecting a portion of the strip substantially vertically out of the plane of movement thereof and swinging freely in an are as said deflected portion assumes an oblique direction with respect to the direction of movement of the strip when the other end of the strip is displaced transversely with relation to the end in said fixed path.
bars, said bracket swinging freely in an are when the other end or the material is displaced transversely of the first mentioned end, whereby the longitudinal edges 0! the material are maintained in parallelism and the strip material is guided into said predetermined path without undue strain upon either edge.
JOSEPH A. BESAL.
CLIFFORD E. IVES.