US1811377A - Web guiding mechanism for printing machines - Google Patents

Description

June 23, 1931. H. v. BALL 1,811,377

WEB GUIDING MECHANISM FOR PRINTING MACHINES Filed NOV. 28, 1928 Patented June 23, 1931 NITED STATES PATENT OFFICE HARRY V. BALL, OF CONCORD, MASSACHUSETTS, ASSTGNOR TO B. HOE & (30., ING, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK WEB GUIDING MECHANISM FOR PRINTING MACHINES Application filed November 28, 1928. Serial No. 322,388.

This invention relates to rotary web printing machines of the perfecting type in which the web is first printed on one side as it passes between the cylinders of a first printing couple and is subsequently printed on the other side as it passes between the cylinders of a second printing couple. The printing cylinders with their plates or impression blankets in place are usually all of equal 10 diameter and they are then driven at the same speed.

In the operation of presses of this type, irregularities are sometimes found in the printing plates and also in the blankets used on the impression cylinder and these irregularities cause the radial dimensions of the cylinders to vary slightly at difierent points on their periphery. When the cylinders are driven at a constant speed these irregularities produce variations in the speed of the web during each revolution of the cylinders, even though the plates and blankets are so applied to the cylinders that their average effective diameters are correct.

In consequence of this condition the section of the web that is between the first and second printing couples is affected by the irregularities of the cylinders of both couples, and as the length of this section of web is e relatively short, a web of material like paper which has very little elasticity, is subjected to intermittent stresses which at times result in breaking it at this point.

'This difliculty has been overcome by the invention disclosed herein, the especial object of which is to provide a yieldingly supported web guide for a perfecting printing machine that will prevent an excessive strain on the web as it passes from the first printing couple to the second printing couple, even though I there are irregularities in the surfaces of the printing cylinders which would otherwise cause the web to alternately slacken and draw taut between the couples.

It is also an object of the invention to provide a web guiding mechanism for printing machines, of generally improved construction, whereby the device will be simple, dura- L'O ble and inexpensive in construction, as well In the drawings which form a part of this specification Figure 1 is an outline View of a portion ofthe side of a perfecting printing machine showing the arrangement of the printing couples and the yieldingly supported web guide that is the subject of the invention; and

Figure 2 is a View of the web and web guide partly broken away and as viewed in the direction of arrow 2 of Figure 1.

Referring to the drawings, 11 and 11 indicate side frames of a printing machine in which the various cylinders are supported in suitable bearings. The web 12 is led from a roll not shown, over the guide roller 13, to

and through the first printing couple which consist of the plate or form cylinder 14 and the impression cylinder 15, where it is printed on one side; thence the web is led around the guide roller 16, to and around the yieldingly supported roller 17', to and through the second printing couple which consists of the plate cylinder 18 and the impression cylinder 19, where it is printed on the opposite side; from there the web passes on to cutting, folding and delivery mechanism not shown on the drawings.

The roller 17 is rotatably supported in bearings formed in arms 20 and 20' which are keyed to the shaft 21, which is rotatably supported in bearings in the frames 11 and 11. The arm 20 is provided with a bell crank extension 22 to which a rod 23 is pivoted. A

lug 24 is secured to the frame 11 and has a clearance hole through which the rod 23 slides, A spring 25 surrounds the rod 23 and its ends abut against the head formed on the rod 23 and the lug 24. The shaft 21 is thus biased in a clockwise direction as shown in Figure 1 and the roller 17 is pressed. against of said guide rollers being resiliently supported, whereby web breaks between the couthe'web 12, its motion in this direction being ples due to variations in the radial dimenlimited by the nut 26 which is threadedon sions of the printing surfaces of the plates the rod23.

An arrangement of inking mechanism well knownto those versed in the art is provided for each of the plate cylinders. The inking mechanism for the cylinder l l includes an ink cylinder 27, distributing rollers, one of which is shown at 28, and form rollers 29.

Similarly, the inking: mechanism for the cylinder 18 includes an ink cylinder 31, dietributing rollers 32 and form rollers 33. Y It-Will readily be seen that should irregu plicable to other arrangements in which are avoided.

- In testimony whereof, I afiix my signature.

HARRY V. BALL.

' larities in the radial dimensions of the cylini there may be additional printing couplesor other mechanism'operating on the web. and it is necessary to provide means to compensate for variations in web speed between the operations. In color printing where four printing couples frequently operate on the same web, yieldingly supported web guides would be used between the several couples and in some cases between the last couple and any mechanism, subsequently acting on the web.

It will thus be seen that by using the yieldingly supported web guides herein disclosed betweenprinting couples or other mechanism cylinder carrying a plate engaging with a acting on a web, that satisfactory operation may be obtained even though certain irregularities are present in the mechanism which would otherwise cause breaking stresses the web.

What; I claim ist In a rotary web printing machine, a first printing couple adapted to print on one side second impression cylinder, inking mechanism below eachof the printing couples, a first guide roller arranged to hold the web in contact with the first impression cylinder after it has passed the line of engagement with the plate on the first plate cylinder, and a second guideroller arranged to guide the web around theinking mechanism for the ,second plate cylinder and to hold the web in contact with the second impression cylinder before'it reaches the line of engagement with the plate on the second plate cylinder; one

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