US2137851A - Printing machine - Google Patents

Description

Nov. 22, 1938.

c. B. NELSON ET AL PRINTING MACHINE Filed Feb. 25, 1937 2 Sheets-Sheet 1 NiOV. 22

c. B. NELSON ET AL PRINTING MACHINE 2 Sheet s 2 Filed Feb. 25, 1957 Patented Nov. 22, 1938 UNITED STATES PATENT OFFICE PRINTING MACHINE New York Application February 23, 1937, Serial No. 127,102

4 Claims.

This invention relates to improvements in printing machines. In machines of the multigraph form, the rotary drums are provided with longitudinal surface slots into which are inserted, through an open end thereof, the type or type bars or slugs having bodies shaped for interlocking engagement with the slots.

The use of cuts for illustrative purposes on conventional multigraph machine drums alone or in conjunction with the conventional type of slugs used in such machines has presented diiiiculties in that it has been necessary to provide such cuts with ribbed formations corresponding to the type bodies which fit within the drum slots not only for the purpose of securing the cuts in place on the drum but for affording support for the printing surfaces of the cuts to prevent inward de flection of the printing surfaces during the printing operations. The material of which the cuts are made of necessity is rather thin and requires support at the transverse zones where the thin metal of which the cuts are formed bridges the drum slots.

One object of the present invention is to provide a segmental drum for a machine of the character mentioned having a smooth unslotted surface and which may be substituted for the conventional slotted drum and used with a printing plate having the copy, or matter to be reproduced including illustrations if desired, etched or otherwise appropriately formed therein, such improved drum having plate attaching means at the longitudinal edges thereof. By the use of such improved drum and plate, the use of type or type bars is eliminated.

Another object of the invention is to provide plate attaching means at the longitudinal edges of the drum, each of which attaching means preferably is adjustable for tightening the plate uniformly upon the drum to prevent relative movement of the plate with reference to the drum during the printing operation and thereby avoiding blurring or producing non-uniform imprints. Since such printing plates are relatively thin and for best results must be attached at several points along each end thereof to retain the same in proper contact with the drum and as the plates also contact with the rotary platen, or the like, during the printing operation, it is essential that the plate attaching means be so disposed and arranged as to avoid any possibility of striking and damaging the platen or other rolls or portions of the machine.

The present improved attaching and tightening means for securing the plates upon the drums (Cl. Mil-415.1)

preferably are disposed in all positions of adjustment inwardly of the cylindrical portion of the drum periphery so as to avoid striking or damaging the platen roller even should the machine be operated inadvertently without completely tightening the fastening means.

Another object of the invention is to provide plate attaching and tightening means comprising a plurality of studs or like members for engaging the ends of the plates within apertures provided therein and all of which members of each of the tightening means are simultaneously and uniformly adjustable by a common operating device.

Other objects of the invention relate to various features of construction and arrangement of parts which will be apparent from a consideration of the following specification and accompanying drawings, wherein:

Fig. l is a perspective view of an improved drum having a smooth unslotted surface and adapted for use on a conventional multigraph machine;

Fig. 2 is an end view of the drum shown in Fig. l but showing a printing plate in conjunction therewith, the plate being shown in initially installed position;

Fig. 3 is a side elevation of a drum and plate embodying the present improvements;

Fig. 4 is a side elevation of an oscillatable rod and plate attaching studs carried thereby which constitute a portion of the plate attaching means;

Fig. 5 is an enlarged broken perspective View of a portion of the shaft shown in Fig. 4;

Fig. 6 is an enlarged broken perspective View of a portion of one of the printing plates showing the stud receiving aperture as being reenforced at its periphery;

Fig. 7 is a plan View of an improved drum showing a plate in position thereon;

Fig. 8 is a plan view of the drum partially broken away prior to the installation of the plate attaching means;

Fig. 9 is a sectional View taken on line 9-9 of Fig. 7 and showing in addition portions of the rotary drum carrying reel or structure of a conventional multigraph machine; and

Fig. 10 is a broken sectional View illustrating a modification of the plate attaching means.

In the drawings, Ill indicates generally a segmental drum adapted to be mounted on the drum carrying rotary structure of a conventional multigraph machine, such structure being indicated fragmentally at H in Fig. 7. The drum has a semi-cylindrical surface l2 upon which is adapted to be secured a printing plate l3. The plate E3 preferably is relatively thin and has its outer surface etched or otherwise provided with the copy to be reproduced including illustrations, if desired. The ends of the plate are provided with apertures I 4 for receiving the fastening means later to be described.

As shown in Figs. 3 and 6, the apertures of the plate preferably are provided with reenforcements I5 such as in the form of grommets, for example, for preventing rupture of the plate during tightening of the latter upon the drum by the attaching means.

The surface of the drum along the longitudinal edges Illa thereof is relieved whereby such surface portions are disposed inwardly of the cylindrical portion of the drum and are provided with longitudinal passages or bores for receiving rods or shafts I6, each of which carries a plurality of plate engaging studs H, the intermediate studs in the form of the invention illustrated operating within transverse slots I8 formed in said edge portions of the plate. It will be seen that the slots I8 permit the studs to be adjusted in directions to effect a tightening or stretching of the plate upon the drum. The slots I8 preferably terminate at ledges I9 which limit movement of the studs in one direction.

Secured to the shafts I6 are arms or levers which project inwardly of the drum as shown in Figs. 1 and 7 and are provided with apertures at their inner ends for receiving bolts 2| pivotally mounted on pins 22 carried in recesses in bosses 23 disposed between two of the intermediate reenforcing ribs 24. It will be seen that by adjusting the nuts 25, the levers or arms 20 can be swung in one direction or another, thereby adjusting the respective shafts I6 and swinging the studs I! to thereby effect tightening of the plate I3 upon the drum or to release the latter therefrom.

As shown in Fig. 7, a spring 26 may be disposed beneath each of the arms 20 for swinging the same outwardly as the nuts are unscrewed from the bolts 2 I. As shown in Figs. 2 and '7, the outer ends of the studs I! are disposed inwardly of the cylindrical surface of the drum, or an extension of such surface, so that in any position of adjustment of the studs, they will clear the platen (not shown) which presses the paper against the plate carried by the drum during the printing operation.

It is preferred that the printing plates I3 be preshaped to approximately the contour shown in Fig. 2 prior to attachment of the same to the drums. However, the plates are thin and quite flexible and may be attached without such preshaping, if desired. When placed upon the drum as shown in Fig. 2, the studs ll of each of the fastening devices are inserted in the corresponding openings I4 of the ends of the plates, after which, by use of a suitable wrench, the nuts are tightened down, thereby effecting movement of the studs in directions to draw the printing plate into firm contact with the surface of the drum. The provision of two tightening devices is preferred for the reason that less tension will have to be applied to the ends of the plates in drawing it into the desired firm contact with the drum than if only one such tightening device were employed. The likelihood of rupturing the relatively thin zinc plate at the apertures is thus reduced.

It will be noted in Fig. 7, which illustrates a printing plate I3 in printing position on the improved drum, that the ends of the plate have been drawn inwardly of the cylindrical portion of the drum surface. The plates, as stated, are thin and flexible and such inward deflection of the plates is due to the fact that the studs I! move in arcs about the centers of the pins or shafts l6 and as the levers 20 are moved inwardly by adjusting the nuts 25, the free edges of the plate I3 are likewise drawn inwardly somewhat and thereby so positioned as to avoid any possibility of striking the machine platen or other portion of the machine structure located close to the drum periphery.

In Fig. 10 of the drawings, the drum I B is similar to drum II] of the above described modification and is provided with shafts I6 carrying studs i! also similar to the corresponding elements above described. In this form of the invention, however, the shaft I8 is provided with a worm wheel 21 which is fixed thereto and which meshes with a worm 28 carried by the key or wrench operable shaft 29. The shaft 29, as shown, is provided with a socket 30 for receiving a suitable key or wrench 3| for operating the same to effect adjustment of the studs I I in tightening the printing plates (not shown in Fig. is) in proper position on the drum.

The drums I9, I0 may be attached to the r0- tar-y structure Ii of the machine by any suitable means such as by the arms 32 which are provided with screws 33 which when screwed inwardly are adapted to seat in sockets provided in the axial shaft 34 of the rotary structure or head of the printing machine as illustrated in Fig. 7. The arms 32 are pivotally attached to pins 35 carried by adjacent reenforcing ribs 24.

Thus it will be seen that one who wishes to use an etched plate, for example, in lieu of the conventional type or type bars may detach the conventional slotted drum from the machine and position one of the improved drums thereon. The improved drum having an unslotted cylindrical or semi-cylindrical surface supports the printing plates throughout the entire printing surface thereof which may be less than, or coextensive with such cylindrical surface. The relieved ends of the drum periphery enable the studs to project through the same for engaging the plates but yet to terminate inwardly of the orbit of the cylindrical portion of the drum so as to avoid damaging any portion of the machine regardless of the position of the studs. The tightening means disclosed are readily accessible and enable the user to secure the thin printing plates to the drum against relative movement during the printing operation, thus insuring unblurred imprints. The etched or otherwise formed printing surfaces of the plates I3 (which surfaces are not illustrated in the drawings) may be for either relief or intaglio printing.

While we have disclosed a certain embodiment of our invention for the purpose of illustration, we do not wish to be restricted specifically thereto except as limited by the appended claims.

1. In a printing machine, a segmental rotary drum having an intermediate semi-cylindrical surface, longitudinal end portions disposed inwardly with respect to said surface, said end portions each having a longitudinal recess therein and transverse slots communicating with said recess, an oscillatable shaft in each of said recesses, plate engaging studs carried by said shaft and movable within said slots, said studs having plate engaging ends projecting beyond the surface of the respective end portions but terminating inwardly of the cylindrical surface of the drum, and means comprising swingable members accessible from the interior of the drum for effecting the adjustment of said shafts for swinging the studs thereof in directions for tightening the plate upon the cylindrical surface of the drum.

2. In a printing machine a segmentary drum having a semi-cylindrical plate supporting surface terminating at each longitudinal end in inwardly curved portions, said portions being longitudinally apertured and transversely slotted, a rock shaft in each of said apertures provided with plate engaging studs extending through said slots beyond the curved surface of the respective end portions but terminating inwardly of the semicylindrical curvature of the drum, a lever attached to each of said shafts, and threaded means within the drum engaging said levers for operating the same to effect movement of said studs in directions for tightening a plate upon the drum and swinging the engaged ends of the plate inwardly of the drum periphery.

3. In a printing machine a segmentary drum having a longitudinally apertured end portion provided with an exterior surface merging with but curved inwardly from the surface of the drum, said end portion having slots therein disposed transversely with respect to said longitudinal aperture, a rock shaft in said aperture, plate engaging studs carried by said shaft and each projecting through one of said slots beyond the adjacent surface of the respective end portion but terminating inwardly of the curvature of the drum periphery, an operating lever secured to said shaft and projecting inwardly of the drum, and threaded means engaging the end of said lever for operating the rod to swing said studs in a direction to tighten an apertured plate engaged thereby upon the surface of the drum and to flex the engaged ends of the drum inwardly of the drum periphery.

4. In a printing machine a segmentary drum having a longitudinally apertured end portion provided with an exterior surface merging with but curved inwardly from the surface of the drum, said end portion having slots therein disposed transversely with respect to said longitudinal aperture, a rock shaft in said aperture, plate engaging studs carried by said shaft and each projecting through one of said slots beyond the adjacent surface of the respective end portion but terminating inwardly of the curvature of the drum periphery, an operating lever secured to said shaft and projecting inwardly of the drum, and threaded means pivotally mounted within the drum and engaging the end of said lever for operating the rod to swing said studs in a direction to tighten an apertured plate engaged thereby upon the surface of the drum and to flex the engaged ends of the drum inwardly of the drum periphery.

CHRISTIAN B. NELSON. BER'I'IL LINDELL.

Images