US2297005A - Relief printing press - Google Patents

Description

Sept. 29, 1942.

S. D. LIVINGSTON RELIEF PRINTING PRESS Filed Nov. 2, 1959 s. ,3 ATTORNE Patented Sept. 29, 1942 RELIEF PRINTING PRESS Stanley D. Livingston, Freeport, N. Y.

Application November 2, 1939, Serial No. 302,479

1 Claim.

This invention relates to high speed, rotary relief printing presses employing stereotype or other relief printing plates, and more particularly a driving mechanism for the inking mechanism of such presses.

A principal object of this invention is the .provision of a novel and improved high-speed rotary printing press, utilizing stereotype or other relief plates, which can be operated safely and for long period of time at higher speeds than is now customary.

A further object of the invention is the provision of a means for driving the inking mechanism from the printing couple so that the normal irregularities in the speed of running the printing couple will not be transmitted to the inking mechanism through the driving means, thereby reducing the breakage'of gears which is now encountered at very high speeds of operation.

' A further object of the invention is the provision of driving means for the inking mechanism in which the gear teeth do not come out of contact with each other while driving, and thus are not subjected to driving loads beyond their capacity.

A further object of the invention is the provision of means for driving the inking mechanism in high speed, rotary relief printing presses come out of contact and then moves them back into contact with a sufficiently heavy impact so that the gear teeth are frequently damaged and soon break, thereby interrupting and decreasing production by the press.

In accordance with the present invention, such a printing couple and ink drum are drivingly interconnected by means of at least one resilient power transmitting element so that the irregularities in speed between the couple and drum are absorbed by the resiliency of the power transmitting element, and the constant rotation of the drum is not affected. Preferably, the ink drum is gear driven from the printing couple and at least one of the gears is formed of resilient material, or includes resilient material, so positioned that it is compressed or tensioned by the power which it'transmits. The resiliency of this element is sufilcient so that its distortion due to the power of such nature that the distribution of ink upon j the form rollers will be more uniform and in consequence the distribution of ink upon the stereotype or other relief plates will be more uniform and so the printing quality of the stereotype or other relief plates will be enhanced.

In the conventional type of high speed rotary relief printing presses, such as are commonly used for printing newspapers, there is provided a printing couple, comprising a plate cylinder and an impression cylinder rotating in contact with each other, and the plates on the plate cylinder are supplied with ink from form rollers which receive ink from a rotating ink drum which is driven from one cylinder of the couple. The cylinders of the couple and the ink drum are large masses and at the relatively high speeds of rotation which are reached during operation, they have very large amounts of inertia. 1

It has been found that in high speed web presses the cylinders of the printing couple do not rotate at a constant speed, but that there is considerable variation in their speed during any revolution, and as the ink drum has a sufficiently large moment of inertia so as to tend to continue to rotate at a constant speed, the backlash which is always present in the gearing forv driving the drum from the cylinders allows the gear teeth to transmission is greater than the lash created by the difference or variation in angular speed between the ink drum and the cylinders.

Not only are the gear teeth on the gears connecting the printing couple with the ink drum in present type presses subjected to destructive forces but the ink drums are not completely uniformly rotated and consequently the form rollers receiving ink therefrom do not have the ink uni-.

formly' distributed thereover, apparently, because a. slip takes place between the ink drum and the form rollers every time a change in speed of rotation of the ink drums takes place. This nonuniform distribution ,of ink on the form rollersiis reflected in the non-uniform distribution of ink on the stereotyped plates or other relief plates and so in the finished printed sheet. The present invention obviates the difiiculties above mentioned and substantially insures a quite uniform distribution of ink upon the form rollers.

Other objects and advantages will appear as the description of the particular physical embodiment selected to illustrate the invention pro gresses, and the novel features will be particularly pointed out in the appended claims.

In describing the invention in detail and the particular physical embodiment selected to illustrate the invention, reference will be had to the accompanying drawing and the several views thereon, in which like characters of reference designate like parts throughout the several views, and in which:

Figure 1 is a diagrammatic side elevation of a high speed rotary, relief printing press embodying the invention; Fig. 2 is a similar view of the other side of the press shown in Fig. 1; Fig. 3 is a fragmentary sectional view on the line III-III of Fig. 2, showing the drive for one of the ink drums; and Fig. 4 is a detailed elevation, with certain parts broken away, of a driving gear utilized in the illustrative embodiment.

Referring now in detail to the illustrative embodiment of the invention as shown in the accompanying drawing; Figure 1 illustrates the drive shaft side of a high speed rotary relief or newspaper printing press. As usual, there are rotatably mounted two printing couples, the printing cylinder III of each couple ing in contact with its impression cylinder I I, the plates of the printing cylinder receive ink from the form rollers l2, and these are in turn inked by the ink drum ll, the distribution rollers l6, the distributing drum l9, the ductor roll 20 and the fountain roll 22. The drive for the press includes the unit drive shaft 26, carrying the bevel gear 28 which meshes with the bevel gear 30 fastened toa spur gear 3|, which meshes with gears 32 and 34, one being carried by the plate cylinder of one couple while the other is carried by the impression cylinder of the other couple. The fountain rollers 22 are driven by means of the beveled gears 36 from drive shaft 38 which is driven from the unit shaft 26 by worm gearing 40.

Figure 2 of the drawing shows the manner in which the ink drums are driven in accordance with the .present illustrative embodiment of the invention, and as shown, each pair of cylinders l and II are provided with meshing gears 42 and 43, so that they are driven in unison. Each cylinder I0 is provided with a resilient gear 44, which meshes with an idler 46 to drive the ink drum ll through the gear 49. .Gear 48 also drives idler 50 and gear 52.

Resilient gears for driving the ink drum l4 and iii are illustratively shown more in detail in Figures 3 and 4 of the drawing, and will be described specifically with reference to the gear 44 for driving the ink drum l4. This gear comprises a hub member 55 keyed to the printing cylinder shaft 56, and held thereon by means of plate 51 and cap screw 58. Integral with the hub, and slightly larger in diameter, is a circular flange portion 59, in the peripheral face of which are a plurality of semi-cylindrical recesses 6|, arranged parallel to each other, extending axially of the flange, and uniformly spaced around its periphery. The recesses 6| open on the outer flat face of the flange 59 and extend across the major portion of the periphery of the flange. Surrounding but slightly spaced away from the flange 59 is an annulus 63, having in its inner face a similar series of semi-cylindrical recesses 62, which register with the recesses 6| in the periphery of member 59. On the outer face of annulus 63 are gear teeth 65,"adapted to mesh with similar teeth on the gear 46. At the open end of the semi-cylindrical recesses GI and 62, the flange portion 59 and the annulus 63 are recessed to receive the annular retaining rings 66 and 61 which are held in the recesses by screws 69.

Annulus 63 is supported on the flange 59 by means of elastic cylinders ll, preferably of rubber, received within the semi-cylindrical recesses 6| and 62, and these cylinders are preferably of slightly larger diameter than the recesses and are adapted to be compressed both by the curved walls of the recesses and by the retaining rings 66 and 61. The cylinders II are thus held in sheer, and transmit the driving force from the shaft 56 and flange portion 59 to the annulus 63. The size 'of the rubber cylinders H and their compression is such that they are substantially compressed or distorted by the driving load transmitted through them, and this compression or distortion is sufficient so'that when the load changes, due to a difference in speed between the drum l4 and the cylinders l0 and II, the teeth of annulus 63 and the teeth of gear 46 do not pass out of contact due to their lash, and thus it is impossible for the teeth to be overloaded beyond their capacity to transmit power.

Although elastic cylinders II are described as the driving means between 59 and 63, it is to be understood that it is not thereby intended to exclude the use of balls or other appropriate shapes.

Although I have particularly described one particular physical embodiment of my invention and explained the operation, construction and principle thereof, nevertheless, I desire to have it understood that the form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

In a high speed, rotary relief printing press, the combination of a printing couple including an impression cylinder and a coacting plate cylinder, an inking mechanism therefor having an ink drum, said cylinders and ink drum having relatively large moments of inertia, and mean for driving the drum from the couple including an annular gear surrounding a hub on a shaft, said gear and hub each formed with a plurality of concentrically arranged registering transverse recesses, resilient members, one in each of the cavities, retaining rings, one attached to the annulus and the other to the hub positioned to retain the resilient members in place, whereby resilient arcuate relative movement between the annulus and gear is permitted and the annulus is also held resiliently axially.

STANLEY D. LIVINGSTON.

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