US2056991A - Printing cylinder - Google Patents

Description

Oct. 13, 1936. J. R. ToMLlN 2,055,991

PRINHNG CYLINDER I Filed March 1s, 1954 2 sheets-sheet 1 Oct. 13, 1936. 1 R TQMLlN 2,056,991

PRINTING CYLINDER Filed March 173, 1934 2 Sheets-Sheet 2 -F'IG.3

I La Patented Oct. 13, 1936 PATENT oFFlcE PRINTING CYLINDER John R. Tomlin, Alexandria, Va., assignor, by mesne assignments, to R. Boe a Co., Inc., New York. N. Y., a corporation of New York Application March 13, 1934, Serial No. 715,315

14 Claiml.

'I'his invention relates to printing cylinders, and more particularly to printing cylinders of the type having gaps, and which are constructed and arranged to operably support exible sheet metal printing plates.

In cylinders of this type, it is desirable that as much of the peripheral surface of the cylinders as possible be utilized for impression purposes, and in certain kinds of printing cylinders, such l0 as those employed in intaglio printing machines for photogravure or rotogravure printing, it is desirable that the entire peripheral surface of the plate cylinders be employed in the printing operation. Until recently, photogravure or rotogravure printing had been done on a printing machine employing a relatively thick copper cylinder or shell mounted on the peripheral portion of the intaglio plate cylinder on which the subject or design had been produced by the usual intaglio pits or wells. 'I'his cylinder rotated in ink which filled the pits or wells of the intaglio design, and the surplus ink was scraped from the face of the plate by the usual stationary doctor plate positioned at a desirable scraping angle 25 relative to the periphery of the cylinder.

This method, while producing satisfactory printing, proved very expensive, especially where a variety of subjects had to be printed. After the required number of prints of a subject had 30 been madehthe peripheral surface of the cylinder was ground down, polished, and a fresh subject then produced thereon; or, alternatively, a large number of expensive intaglio printing cylinders had to be kept in store.

35 More recently it has been proposed to mount a flexible printing plate, having a design in intaglio thereon, around the periphery of the cylinder, the terminals of the plate being suitably secured to'the cylinder. 'I'hese flexible plates 40 are capable of ready removal and replacement, and this arrangement has considerably reduced the cost of photogravure or rotogravure printing.

' However, the existing devices and means for securing the exible printing plate to the periphery 45 of the cylinder are either very expensive to manufacture, lack sufficient rigidity, or leave gaps between the plate terminals which interfere with the operation of the doctor blade. As hereinbefore stated, it is desirable that certain types of 50 printing cylinders, which operably support ilexible sheet metal printing plates, be constructed and arranged to utilize as much as possible of the periphery of each printing cylinder for impression purposes. This is particularly so in 0H- 55 set printing presses employing flexible sheet zinc (Cl. 1in-415.1)

planographic plates. In this type of press, by employing the entire peripheral portion of the plate cylinder for impression production, a larger sheet for a given cylinder size can be printed, and continuous designs can also be printed on 6 webs in offset web printing or web perfecting presses.

An object of the present invention is to provide a printing cylinder having operable components for securely binding a flexible printing plate l0 around the periphery of theA cylinder, the cylinder and the components being constructed and arranged so that the entire circumference of the cylinder is made available for impression pro-` duction. l5

Another object of this invention is to provide a plate cylinder for receiving a exible printing plate around the periphery. thereof, the cylinder having components operable to securely lock the flexible printing plate on the cylinder, and coacting to ll the peripheral portion of the cylinder gap to thereby complete the cylinder periphery.

A further object of the invention is the fprovision of a printing cylinder incorporating means for securing one terminal of-a flexible printing plate to the cylinder, and coacting components, to one of which the plate terminal is secured, operable to securely bind the flexible plate around the cylinder, and to intert to close the cylinder gap and to securely lock the plate in printing position.

An additional object of the invention is to provide a printingcylinder having a flexible sheet metal printing plate thereon, and coacting members for locking the plate in printing position and for filling the peripheral portion of the cylinder gap, and manually operable means for actuating the coacting plate locking members and for rigidily supporting them against movement under impression stresses when in their plate securing or gap filling position.

It is also an object of my present invention to provide a printing cylinder of generally improved construction and arrangement, whereby the device will be simple, durable and inexpensive in construction, as well as convenient, practical, serviceable and eilicient in its use.

With the foregoing and other objects in View, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood that various changes in form, proportions and minor details of construction spirit or sacrificing any advantages of the invention.

For a complete disclosure of the invention, a detail description of a printing cylinder embodying the invention in a preferred form will now be given in connection 'with the accompanying drawings forming a part of this specification, whereint- Figure 1 is a fragmental elevation, parts appearing in section, of one end of a printing cylinder, its components shown in plate securing position;

Figure 2 is a fragmental vertical section depicting one end of the improved printingl cylinder, parts appearing in elevation, the view looking in the direction, of arrow 2 of Figure 1;

Figure 3 is a fragmental plan view of one end of the printing cylinder, parts appearing in section, the view being taken in the direction of arrow 3 of Figure 4; and

Figure 4 is a fragmental elevation, similar to Figure 2, but depicting the plate clampingl components in plate releasing position.

Referring to the drawings, in which similar reference characters designate corresponding parts, Il) indicates a printing cylinder of the type employed in photogravure or rotogravure and offset printing, the cylinder-being provided with a gap II. An undercut recess I4 is formed in the gap II at one side thereof for the reception of a clamping bar I5, which is secured to the cylinder by suitable clamping screws or members I6. One terminal I 8 of a flexible sheet metal printing plate I9 is clamped within the recess I4 by the bar I5, and the plate is then bent around the periphery of the cylinder I0, and its opposed terminal secured within a recess 2|, formed in the plate .clamping or securing member 22, by means of a clamping bar 23, which is secured to the member 22 by suitable clamping screws ormembers 25. The printing plate I9 may be of the usual planographic type vemployed in offset presses, or it may have its design produced in intaglio thereon by means of the usual pits and wells. When employed as an intaglio printing plate, the cylinder, in conformity with present practice, rotates in an ink fountain, thereby depositing the ink in the intaglio cavities, and the surplus ink is then scraped from the surface of the plate by means of the usual doctor blade, not shown, but the construction and purpose of which is well understood by those skilled in the art.

The plate clamping or securing member 22 is movable within the gap II for securing and releasing the flexible plate I9, and in the preferred construction illustrated, it is pivotally secured to brackets 28 by means of suitable shaftsor trunnions 29, and the brackets 28 are secured/to the cylinder I0 by suitable machine screws or securing devices 30. In order to positively move the plate securing member 22 about its pivotal point 29 to force or stretch the plate I9 into secure printing position, a coacting member or wedge 35 is provided and is arranged to slide within the gap II and a recess 36 which communicates with the gap. The opposed walls 38 and 39 of the recess 36 and gap II positively guide the wedge or member 35 for right line or rectilinear motion, and suitable instrumentalities, to be hereinafter disclosed, are provided for imparting motion to the wedge 35. The plate clamping member 22 is provided, at a point remote from its pivotal point 29 with a hardened angularly disposed wedge engaging surface 40, and an outer arcuate sursurface 40 of the member 22 to move the member 22 to closed or plateclamping position. An arcuate surface 44 is formed at the outer terminal of the wedge 35, and its arc isalso concentric with the arc of the cylinder periphery. The outward sliding motion of the sliding block or wedge 35 is limited by a shoulder 45 formedA in the wall 39, and a similar shoulder 46 formed in the wedge 35. In order to secure the wedge 35 against longitudinal motion in its recess 35, suitable guidel pins or dowels 43 are secured vto the wedge 35, as indicated at 49, and these dowels are slidably received in cylindrical recesses 50 formed in the cylinder I8.

In order to positively move or slide the wedge 35, an annulus or toggle ring 55 is mounted on each end of the cylinder shaft I2, and each ring has a connecting member or .link 56 pivotally secured thereto, as indicated at 51, and the vopposed terminal of this link is pivotally secured to the slidable wedge 35, as indicated at 58. By this arrangement,y as the ring 55 is rotated on the shaft I2, it, coacting with the linkf56, prof duces a toggle action which forcibly moves the wedge 35 outwardly, and the wedge, in turn, by the engagement of its angularly disposed surface 43 with the similar surface 40 of the platesecuring member 22, moves the plate securing member to plate securing position.

A shaft 60 extends longitudinally through the cylinder and is .mounted for rotation within the cylinder. At the opposed ends of this shaft there are provided suitable pinions 62, having teeth 63, which mesh with similar teeth 64 formed on the outer periphery of each toggle ring 55, and a wrench engaging or actuating head 66 is formed at each end of the shaft 60.

A pawl 10 is pivotally secured to the cylinder Il), as indicated at 1I, and this pawl is provided with teeth 12 which engage the teeth 63 of the pinion 62, thereby locking the pinion 62 against rotation. The free Vend of the pawl 10 is yieldingly pressed toward the pinion 62 by a spring 14, which has one end secured to the cylinder, as indicated at 15, and its opposed terminal engaging the pawl 10. A manipulating handle 16 is secured to the free toothed end of the pawl 10, and this handle extends through a slot 11, formed in one of the casings 18 arranged to house the mechanism operably located at each end of the cylinder I0.

Inasmuch as the mechanism at each end of the cylinder is provided in duplicate, only oneend of the cylinder is here illustrated, but it is, of course, to be understood that both ends are similar in construction and arrangement to that illustrated, except that it is not necessary to employ more than one locking pawl 10.

In operation, assuming that the parts are in Y 60, and thering 55 is thereby rotated counterclockwise. Inasmuch as the pivotal point 51 oi' the ring 55 moves about the center ofthe shaft I2, a toggle action is produced between the ring 7o v is placed on the squared portion 66 of the shaft and the link 58 thereby forcibly moving the wedge outwardly, which, in turn, forces the plate securing member y22 about its pivot 29 to the position indicated 'in Fig. 1, thereby drawing the plate I3 around the cylinder I0 and immovably securing it to the periphery of the cylinder. It is to be understood, of course, that the terminals of the plate have been previously secured in the recess I4 and 20 of the cylinder I0 and the plate securing member 22 by the clamping bars I5 and 23. `In order to insure that the plate willbe of proper dimension to accurately fit the periphery of thev cylinder it is preferred that the plate first be bent around a template of predetermined dimensions and then secured, as described, to the cylinder.. When the components of Athe cylinder are in plate securing position, as shown in Fig. 1, the pivotal joint 5'I will have moved slightly beyond a radial line passing through the pivotal point 58 and the center or axial point of the shaft I2, and in this position the locking pawl 'I0 is moved into engagement with the teeth of the pinion 82, thereby rigidly securing the wedge 35 and plate securing member 22 against retrograde or inward motion.

When the cylinder is constructed and arranged for photogravure or rotogravure printing, it is necessary that the interfltting parts adjacent the periphery of the cylinder Ill be accurately proportioned and accurately interfltted to insure an uninterrupted peripheral surface. The components of the cylinder are in manufacture, moved to plate securing position, as indicated in Figure 1, before the periphery of the cylinder is given its flnal dimension, and then the cylinder is ground down to predetermined dimension' so that the arcuate surfaces 4I of the plate securing member 22 and the arcuate surface 44 of the wedge 35 accurately coincided with the arc of the cylinder periphery. The wedge engaging surface 40 of the member 22 and the angular surface 43 of the Wedge 35, together with the opposed sliding surfaces of the wedge 35 and the wall surface 39 of thegap II are accurately ground to produce precision fit, thus when the components are in plate securing position uninterrupted peripheral surface is produced, thereby insuring a continuous support for the flexible plate I3 to prevent the interfltting joints of the components affecting the printing or impression surface of the plate'.

When the plate is employed in intaglio printing, the minute recess or cavity defined by the small arcs 30 of the abutting terminals 'II of the plate I9 may be filled by suitable plastic composition, which, when hardened, will present a smooth surface for operable engagement with the doctor blade, thus producing an uninterrupted peripheral plate surface so that any preferred design may be employed in either intaglio or offset printing without affecting the continuity of design, in oifset work, or interfering with the operation of the doctor blade, in gravure printing.

Having-thus described my invention, what I claim as new and useful in 'the art isz- 1. A printing cylinder having a gap, means for securing one terminal of a flexible printing plate to the cylinder, coacting movable members, means for securing the opposed terminal of the flexible printing plate to one of the coacting movable members, means operably supported by the cylinder for forcibly moving one of the movable members thereby forcibly moving the lcoacting movable members to plate securing position to supported by the cylinder, means for securing -the opposed terminal of the printing plate to the movable'member, a second movable member slidably supported by the cylinder and operably engaging the first movable member to forcibly move the first movable member about its pivot to plate securing position, thereby securely binding the flexible plate around the periphery of the cylinder, each movable member having an arcuate surface of the same radius as the periphery of the cylinder so that said arcuate surfaces coincide with the rperiphery of the cylinder I when the movable members are in plate securing position thereby closing the gap to complete the peripheral portion of the cylinder.

3. A printing cylinder having a gap, means for securing one terminal of a flexible printing plate to the cylinder, a movable member operably supported by the cylinder and having an arcuate surface of the same radius as the cylinder, means for securing the opposed terminal of' the flexible printing plate to the movable member, a second movable member vsupported by the cylinder and having an arcuate surface of the same radius as the cylinder, means operably supported by the cylinder for operating the second movable member to cause it to operably engage the flrst movable member to forcibly move it to -plate securing position to securely bind the flexible plate around the periphery of the cylinder and to close the gap so that the said arcuate surfaces complete the peripheral portion of the cylinder.

4. A printing cylinder having a gap, means for securing one terminal of a flexible printing plate to the cylinder, a movable member pivotally supported by the cylinder and having an arcuate surface of the same radius as the cylinder, means for securing the opposed terminal of the flexible printing plate to the movable member, a second movable member slidably supported by the cylinder and having an arcuate surface of the same radius as the cylinder, means for moving the second movable member to operably engage the flrst movable member to forcibly move it to plate .securing position thereby securely binding the flexible printing plate around the periphery of the cylinder, the arcuate surfaces of both movable members coinciding with the periphery of the cylinder when in plate securing position to close the gap and complete the peripheral por-A vses ble means operably supported by the cylinderfor index-,both movable members being constructed and arranged to move in the' gap away from the periphery of the cylinder to open the gap and to move toward the cylinder periphery so that the Aarcuate surfaces thereof coincide with the periphery of the cylinder when in plate securing position to closethegap and complete the peripheral portion of the cylinder. v

8. A printing cylinder having a gap, means for Vfr0-*securing one terminal of a exible printingplate ported by the cylinder and having an arcuate' to the cylinder, a movable member pivotally supsurface of the same radius as the cylinder, means for securing the opposed terminal of the flexible printing plate 4te `the pivotally supportedA movable member, a second movable member slidably supported by the cylinder and operably engaging the ilrst movable member and having an arcuate surface of the same'radius as the cylinder,

manually operable 4means operably supported in i the cylinder for forcibly moving the second movable member into operable engagementwith the first movable member to force the movable members to plate securing position thereby securely binding the flexible printing plate around the periphery of the cylinder, the arcuate surfaces of the movable members coinciding with the periphery of the cylinder when the movable members are in plate securing position to close the gap and complete the peripheral portion of the cylinder, means for operating the second movable l no member, the second movable member being positioned to operate within the gap and constructed and arranged to operably engage the first movable member to forcibly move it to plate securing position thereby securely binding the flexible printing plate around the periphery of the cylinder, the arcuate surfaces of both movable members coinciding with the periphery of the cylinder when the movable members are in plate securing position to close the gap and complete the p'eripheral portion of the cylinder.

8. A printing cylinder having a gap, means for securing one terminal of a exible printing plate to the cylinder, a pivotally supported member movable within the gap and having a wedge engaging surface and an' arcuate surface of the same radius as the cylinder, means for securingV the opposed terminal of the flexible printing plate to the pivotally supported member, a slidable wedge movable within the gap and having an arcuate surface of the same radius as the cylinder, means for operating the wedge; the wedge being constructed and arranged to operably engage the wedge engaging surface of the pivotally supported member to force the pivotally supported member to plate securing position thereby securely binding the flexible printing plate around the periphery of the cylinder, the arcuate surfaces ofthe pivotally supported member and the wedge coinciding with the periphery of the cylinder 'when the said member 'and wedge are in plate securing position to close the gap and complete ythe peripheral portion of the cylinder.

i 9. A printing'cylinder having a sap. means for ,securing one terminal of 'a i'iexible printingr plate to the cylinder., a pivotally supported' member having an' arcuate surface, means for securing Vthe opposed terminal of the exible printing plate fto the pivotally supported member, a wedge having an arcuate surface, means for'operating the wedge, thewedge being constructed and arranged to operably engage the pivotally supported member toy force it to plate securing position vthereby l'o securely binding the flexible printing plate around .the periphery of the cylinder, the pivotallyfsupported member and the wedge being constructed and arranged so that their arcuate surfaces coinple, securing position to close the gap and complete the' peripheral portion ofthe cylinder.

l0. A printing cylinder having a gap, means for v cidzwith the periphery ofthe cylinder when iiiv ported member, a slidable wedge having an arcu- ,l

ate surface, means for operating the wedge, the wedge being constructed and arranged to operably engage the wedge engaging surface of the pivotally supported member to force the pivotally sup'- ported member to plate securing position, thereby securely binding the flexible printing plate around "so the periphery of the cylinder, the pivotally supported member and the wedge beingconstructed and arranged so that their arcuate surfaces coincide with the periphery of the cylinder when in plate securing position to close the gap and complete theperipheral portion of the cylinder.

-.11. A printing cylinder having a gap, means for securing one terminal of a flexible printing i plate to the cylinder, coacting movable members,

`means for securing the opposed terminal of the flexible .printing plate to one of thecoacting movable members, meansfor forcibly moving the coacting movable members to plate securing position thereby securelybinding the flexible plate around the periphery of the cylinder, stop means for limiting the movement -of the coacting movable member in plate securing position; both movable members being constructed and arranged so that portions thereof coincide with theperiphery of the cylinder when in plate securing position to close the gap and complete the peripheral portion of the cylinder.r

12. A printing cylinder having a gap, means for securing one terminalv of a flexible printing plate to the cylinder, coacting movable members having arcuate surfaces. means for securing the opposed terminal of the flexible printing plate to one of the coacting movable members, means for forcibly moving the coacting movable members to plate securing position, thereby securely binding the flexible plate around the periphery of the cylinder, stop means for limiting the plate securing movement of the coacting movable members when their arcuate surfaces coincide with the periphery of the cylinder, thereby positioning the movable members to close the gap and complete the peripheral portion of the cylinder.

13. A printing cylinder having a gap, means for securing one terminal of a flexible printing plate to the cylinder, coacting movable members having arcuate surfaces, means for securing theP ing the flexible plate around the periphery of the cylinder, stop means for limiting the plate securing movement of the coacting movable member when their arcuate surfaces coincide with the periphery of the cylinder thereby positioning the movable members to close the gap and complete the peripheral portion of the cylinder, and means for securing the movable member in plate securing position.

14. A printing cylinder having a gap, means for securing one terminal of a flexible printing plate to the cylinder, a plvotally supported member having an arcuate surface and a wedge engaging surface, means for securing the opposed terminal of the exible binding plate to the plvotally supported member, a slidable wedge having an arcuate surface, means for forcibly moving the wedge so that it operably engages the wedge engaging surface of the pivotally supported member to force the pvotally supporting member to plate securing position thereby securely binding the flexible printing plate around the periphery of the cylinder, stop means for limiting the plate securing movement of the Awedge when the arcuate surfaces of the wedge and the pivotally supported member coincide with the periphery of the cylinder, thereby positioning the wedge and the pivotally supported member to close the gap and their arcuate surfaces to complete the periphery of the cylinder, and means for securing the wedge in plate securing position.

' JOHN R. TOMLIN.

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