US1720776A - Tension device for printing webs - Google Patents

Description

July 16, 1929. H. A. w. woon TENSION DEVICE FOR PRINTING WEBS.

2 Sheets-Sheet l Original Filed Sept. 10, 1923 July 16, 1929. H. A. w. wooD v TENSION EVICE FOR PRINTING WEBS Original Filed Sept. l0, 1923 2 Sheets-Sheet 2 N QF Patented July 16, 1929.

UNITED STATES PATENT OFFICE.

HENRY A. WISE WOOD, OF NEW YORK, N. Y., ASSIGNOR TO WOOD NEWSPAPER MA- CHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

TENSION DEVICE FOR PRINTING WEBS.

Application filed September 10, 1923, Serial No. 661,887. Renewed November 3, 1928.

This invention relates to means for providing equalized tension on a web of paper in a printing press at some point between two points along the web that are held unyicldingly. A

The principal objects of the invention are to provide means for maintaining a length of web at a given tension; to provide such a tension device in a form in which either edge of the web can yield independently of the other; to provide the tension device so it can be placed at any convenient position between two areas of the web at which the web is gripped or nipped between two elements; and to provide a construction for the tension device of such a nature that the web can pass over it freely and it will be supported to permit the necessary give and take.

The invention also involves other details and features of construction as will appear.

Reference is to be had to the accompanying drawings, in which Fig. 1 is ay diagrammatic side view of a portion of a perfecting web press, partly in section, showing several places in which tension devices can be located in accordance with this invention;

Fig.v2 is an elevation of a tension roller with its supporting means;

Fig. 3 is a sectional view of the same on the line 3 3 of Fig. 2;

Fig. 4 is central section of the supporting device at one end of the roller; and

Fig. 5 is an enlarged sectional view of part of one of the spring adjusting nuts.

There are several points in the course of a web through a printing machine on both sides of which the web is held unyieldingly, usually by being gripped between rotating surfaces. The web has to travel at a definite speed and at substantially the same speed at all points. Therefore if for any reason there is any obstruction, lack of lubrication, or other variation to cause a change in the relative speeds of the rolls or cylinders the web will break or else crumple up unless some means is provided to take up the slack and yield in case of increased strain.

In Fig. 1 I have shown diagrammatically a printing press in which the web comes from a. roll and is gripped between the first cylinders of the printing couple 11 and 12. At some intermediate point between the cylinder couples of the press I provide a tension and take-up device indicated at a to allow the web to go in either direction and keep it taut at all times. Another one b is located between the point at which the web is gripped between the last printing couple and the gripping point between the slitter rolls 13. This web is shown asbeing slit and another pair of tension and take-up devices. 0 0 are located on each slit web between the slitter and the place where the web is nipped between the propeller 14. and drag roll 15. In all those places the tension rollers are placed between between two pairs of rotary members. I do not necessarily mean that these are all the points at which the invention can be applied, but it is understood that it can be used wherever necessary.

On the second sheet of drawings I have shown one of these tension and take-up devices. The same construction can be used in all of them. Bolted on the inner sides of the opposite side frames 16 of the machine are located two casings 17. Each one has an opening 18 in the surface which is adapted to rest against the supporting frame 16.

In the assembling of the parts two spring adjusting nuts 19 are introduced, one after the other, through this opening, moved outwardly in opposite directions, and screwed outwardly to receive springs and provide the proper tension as will appear. Each one is provided at the end with a surface 20 which is not screw-threaded so as to prevent their being adjusted far enough to come out through the ends of the casing 17. They can be taken out inwardly through the opening 18 when the casing 17 is removed from the frame. Each of these nuts is provided with a transverse passage 21 for receiving a rod for turning it for adjusting purposes. It is also provided with a central passage for a threaded rod 22. These two rods 22 are slidably located in these passages and provided with a transverse slot 23 so that they can be screwed into a cast head 24 at the center of this device. The nuts and the ends of this head are provided with circular seats 26 for a pair of springs 25. The resistance of these springs is regulated by turning the two nuts. They are adjusted to hold the casting 24 normally in exactly central position, the two springs being of the same size and number of coils. f

The casing 17 is provided with an opening 27 on the side opposite the opening 18. Through this opening projects a bolt 28 extending through t-he center of the head 24e and screwing into a shaft 29. T his shaft extends across the frame and is held in the same way at. the other end. It is provided with a head 30 having an anti-friction bear ing 3l at each end. The bolt 28 draws the shaft and head 30 up toward the casting 2e so that a collar 33 on the head 30 rests up tightly against the casting 2st. These parts are held against rotation. @n the opposite bearings 31 is mounted to rotate freely a roller 32 which receives the web. rollers are in the form of hollow cylinders fixed on the outer rings of the roller bearings at both ends.

rlhe device is set up so that the aXis of the two spring 25 bisects the angle of the web in which the tension device is located. Any increase or decrease of the extension on the web will cause the roller 3Q to move in one direction or the other enough to take up the slack or yield to the drag at either end. The opening 27 is large enough to allow the roller to move in either direction as much as it is ever likely to do.

On the head 24 is located an indicator pin 34.-. lIhis projects through an opening 35 in the wall of the casing 17. Normally this pin is located centrally in this opening. Any motion of the tension roller 32 in either direction at the end is indicated by it so that the operators are always able to see from a distance how the web is running. In case of .any excessive strain or slack they are warned in time to stop the machine if that should be necessary. The parts of course are adjusted so that the springs exert the same pressure at both ends of the roll and on both sides.

A tension device of this character can be located in any of the positions shown in Fig.-

l to perform its functions in the manner above described. It acts in both directions and at both ends independently and provides for taking up the slack as well as yielding to an increased strain, thus shortening the web path materially in the latter case and vice versa. It is also instantaneous in its action and after the strain is removed will immediately return to normal position automatically.

Although I have illustrated and described only a single form of the invention and shown it as applied only in certain particular places in a single form of press, I am aware of the fact that modifications can be made in the construction and arrangement of the parts, especially in its location on the press without departing from the scope of this invention as expressed in the claims. Therefore I do not wish to be limited in these respects, but

What I do claim is l. In a web press, the combination with means for guiding and feeding 'the web, of a. guide roll-er located at a pointbetween two These maarre parts of the web where it is unyieldingly gripped and springs on both sides of the roller at the ends, the axes of said springs being arranged substantially to bisect the angle of the web at the point at which ther roller is located for yielding to increased strain on the web and taking up the slack.

2. In a web press, the combination with a printing couple and a pair of rotary members to which the web passes therefrom and between which. it nipped, of a fre-ely rotatable roller between the couple and rotary members engaging the web, yielding means on one side of the roller tending to force it yieldingly toward the web and opposite yielding means tending to force the roller in the opposite direction. l

3. In a web press, the combination with a printing couple and a pair ofrotary members to which the web passes therefrom and between which it is nipped, of a freely rotatable roller between t-he couple and rotary members engaging the web, yielding means on one side of the roller at bot-h ends tending to force it yieldingly toward the web and opposite yielding means at both ends tending to forcel the rolle-r in the opposite direction, said yielding means at the two ends of the roller being capable of acting independently.

Il. In a web tension device for a printing press, the combination with a roller over which the web is adapted to pass, a shaft therefor'. means for mounting the roller on the shaft to rotate freely thereon, and yielding means for resisting the motion of the roller out of normal position in opposite directions.

5. In a web tension device for a printing press, the combination with a tension roller for the web comprising a hollow cylinder, of al non-rotatable shaft passing through the cylinder, anti-friction bearings for support-- ing the roller from the shaft. a pair of supports for the opposite ends of the shaft mov ably mounted, and yielding means for carrying said supports comprising a pair of springs projecting from the supports in opposite directions.

6. In a tension device for a web press, the combination with a roller over which the web is adapted to pass, of a head at the end for supporting the end of the roller and having means for allowing the roller to rotate freely with respect thereto, a pair of studs projecting from the head in opposite directions, a casing in which said studs are located fixed on the frame of the machine, a pair of nuts adjustably mounted in said casing and located opposite each other, said nuts and heads having seats opposite each other, and a pair of coiled springs located in said seats for' holding the head yieldingly in central position and permitting it to move therefrom against the action of said springs.

7. In a device of the character described,

the combination of a ,stationary hollow casing adapted to be secured to the frame of a printing machine and having an opening through its base, the casing having a pair of opposite screw-threaded openings having their aXis parallel with the plane of the base, a pair of nuts adapted to be inserted in the last named openings through the first opening and threaded to fit the threaded openings and each having means at its inner end for preventing it from being unlsorewed entirely7 in an outer direction, a spring supported by each of said nuts and projecting inwardly therefrom, and a guide roller for a web supported by said springs.

8. In a web press, the combination with a set of perfecting cylinders for nipping a web at a plurality of points and feeding it, of a resilient guide engaging the web between two nipping points to keep the web under suitable tension atall times.

9. In a web press, the combination of two printing couples adapted to perfect a web and a resilient guide engaging the web between the two printing couples so as to kee the said web under suitable tension during t e operation of the machine.

In testimony whereof I have hereunto affixed my signature.

HENRY A. WISE WOOD.

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