US2035630A - Printing plate cylinder - Google Patents

Description

March 3l, 1936. A W WOOD PRINTING PLATE CYLINDER NNI kw Filed Feb. 8, 1935 mi, x.

Patented Mar. 3l, 1936 UNITED `sra'llzs PRINTING PLATE CYLINDER Henry A. Wise Wood, New York, N. Y., assignor4 I to Wood Newspaper Machinery Corporation,

New York, N. Y., a corporation of Virginia Application February 8, 1933, Serial No. 655,683 solaim's. (ci. 1011-378) The principal objects of this invention are to provide a printing plate cylinder with means thereon for clamping the printing plates inside their surfaces so that the clamping means engaging the beveled and straight edges of the plates are not depended upon entirely for. holding the plates, and to provide a construction of the cylinder which will enablethe printing plates to be made without necessitating any edge matelo rial solely for clamping purposes, thereby permitting the employment of very narrow margins and an addition to the printed matter on each page.

Other objects and advantages of the invention Will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is a radial sectional view of a part of a printing plate cylinder showing three plates thereon clamped in accordance with this invention;

Fig. 2 is a similar view showing the end plate unclamped;

Fig. 3 is a similar view showing the position of the end plate when ready to be removed from the cylinder; v

Fig. 4 is a modication like Fig. 1 showing the entire elimination of surfaces on the plates for use in clamping the plates on the cylinder, thus enabling the plates to be made with the narrowest possible margins.

In printing plants using stereotype plates it has been customary to secure the plates on the plate cylinders by beveled clamps operating against beveled curved edges of the plates. In some cases the straight edges of the plates also are beveled and clamped down on the cylinder. The trend in newspaper plants has been toward higher speeds and the edge clamping means have not always proved suilicient to hold the plates under the increased centrifugal force produced.

In the newspaper printing business there has been an ever increasing demand for narrower margins on newspapers. With the customary beveled edges for engagement with end clamps, center clips, and center rings, there is an irreducible limit in margins below which it is impossible to go. One object of this invention is to reduce and in fact, in some cases, eliminate the beveled edges and thus that part of the plate at the edges which is employed for clamping purposes only. Thus the plates can be made with the narrowest possible margins and there will have to be no additional metal employed for clamping purposes. AIn other words, the entire surface of the plate can be used forprinting matter and plates of the same size as are now used and will furnish more Yroom for printing surfaces. y

In the form shown in'. Figures 1, 2 and l3 the printing cylinder I0 is provided on opposite sides of the middle of the cylinder with sets of` integral projections II inclined in one direction and inclined in opposite directions on opposite sides lo' of the center. These projections are all inclined at the Vsame vangle and at the same angle on both sides of each projection.

In thisforma center clip I2 is used and a center ring I3, the center ring being the same I5' as usual and the center clip having projections on its opposite sides operating in ways I4 and being free to move back and forth to accommodate the plates. Also an end clamp I5 is used having a usual operating means I6. -Of course, 20 the end clamp, center clamp, and center ring are provided with beveled edges I1, I8 and I9 for engaging the beveled edges of the printing plates P and holding them in position;

The center ring being stationary and the cen- 25 ter clip movable, the inside plate can be clamped Aagainst the center ring and the outside plate between the center clip and the end clamp by motion of the end clamp alone. These beveled surfaces are employed here as usual for cases in 30 which it is not desired to change the shape of the plates. In all cases, however, the projections II engage in recesses or indentations 20 on the inner or concave sides of the plates. These recesses have beveled edges beveled on the same 35 angle as the projections I I and beveled the same way at the inner and outer end. The recesses are at least long enough to receive a projection plus the length required by the bevel at its end. Thus they can receive these projections as shown 40 in Fig. 3. The plates can be moved along to the position shown in Fig. 1 by the end clamp and the plates will be held rmly.` These bevel surfaces hold the plates on the ,cylinder at points between the edges of the plates and assist in 45 preventing the plates being dislodged or loosened by the high degree of centrifugal force to which they are subjected in modern newspaper practice. The clamping along the straight edges oi' the plates canbe eliminated in Vsome cases. 50

In the form shownvin Fig. 4 a construction is shown in which the clamping-by the center clip and center ring can be entirely avoided and the surfaces of the plate employed for clamping the plate in position are entirely eliminated from the 55 all four plates have square ends and they all abut against each other. These plates are held by the projections Il above described in the recesses 20 and not by the center clips and center ring heretofore employed. This not only eliminates the bevel undercut on the end clamp but entirely' eliminates the center clips and center rings. It will be seen that in this form of the invention the margins can be reduced to an absolute minimum and the amount of printing on the page will reach the maximum.

In this first formi it will be obvious that the .projections il on one side of the center ring I3 slant in one direction, whereas the corresponding lprojections l I- on the other side of the center ring slant in the opposite direction, but in the form shown in Fig. 4 theycan all slant in the same direction, as there is no stationary center ring or any substitute for it employed, the plates being clamped simply between the end clamps. It will be obvious that the plates are easily removed simply by moving the end clamp out as shown in Fig. 2 and then moving each plate a little ways in the same direction as shown in Fig. 3.

Although I have illustrated and described only two forms of the invention I am aware of the fact that other modifications` can be made therein by any person skilled in the art without departing from the scope of` the invention as expressed in the claims. Therefore, I do not wish to be limited in this respect otherwise than as set forth in the claims, but what I do claim iszl. As an article of manufacture, a printing plate cylinder having integral inclined projections on its surface slanting away from the middle of the cylinder for holding the printing plates thereon at points within their surfaces, said projections on one side of the longitudinal middle of the cylinder all slanting in the same direction longitudinally.

2. As an article of manufacture, a printing plate cylinder having integral projections on its surface for engaging in corresponding recesses in the printing plates and end clamps engaging the curved ends of the printing plates constituting the sole means separate from the printing cylinder for clamping a series of plates in position.

3. The combination with a printing plate cylinder having integral inclined projections on its cylindrical surface, of a fixed center ring having inwardly beveled undercut surfaces for receiving the edges of the inside plates; a longitudinally movable center clip having rearwardly beveled undercut recesses for receiving the beveled edges of an outer and inner plate, and an end clamp having an inwardly beveled edge slanted in a direction opposite to that of the recesses of the center clip for receiving the outer edge of the outer plate, positively holding the plate between it and said projections, and constituting a movable means for clamping an inner and outer plate on the cylinder.

4. The combination of a printing plate cylinder having slanting longitudinal projections extending outwardly from the surface thereof, and

a movable end clamp having a surface in a plane f perpendicular to the axis of the cylinder for engaging the end of a printing plate and moving the plate along the cylinder so that said slanting projections will hold the plate by engagement with the slanting surfaces of their recesses.

5. The combination with a printing plate cylinder having a series of projections on its surface, all slanting in the same direction, a series of vcurved printing plates thereon, each having recesses in its concave surface for receiving said projections and having square edges, said square edgesabutting against each other, and an end clamp having a square surface abutting against the square edge of the outer platel for forcing said plates along the cylinder to cause them to be clamped by said projections.

HENRY A. WISE WOOD.

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