US2048005A - Cylinder for printing machines - Google Patents

Description

July 21, 1936. A. J. HoRToN CYLINDER FOR PRINTING MACHINES Filed Dec. 20, 1954 w. ww

INVENTDR.

Patented July 21, 1936 YUNITED y STATES ATENT OFFICE CYLINDER FOR PRINTING MACHINES Application December 20, 1934, Serial No. 758,428

i2 claims.

This invention relates to a cylinder structure which is especially applicable to printing machines of the type used for rotary intaglio printing. In machines of this kind, the form cylinders are removed from the machine in order to prepare Ythem for printing, this procedure being necessary every time the form is changed, and for this reason, it is desirable that the weight of the cylinder be kept to a minimum. In operation, an impression cylinder presses the web against the form cylinder continuously, there being no intermittent relief from pressure as is the case in printing machines which print from plates that are clamped to the cylinder. This pressure causes the cylinders to be deflected along their contact areas, and in consequence less pressure is exerted at a spot in the center of the contact area than elsewhere, the pressure varying from a minimum at the center, to a maximum at the ends. Obviously this variation in impression pressure is objectionable for the best results are attained when the pressure is equal over the entire printing surface.

In the cylinder structure according to the presentinvention, a certain amount of deflection will occur at the center of the cylinder, but instead of being deflected only at the center, the cylinder herein Vdisclosed is also deflected at both ends. By permitting a deflection of the cylinder at its ends as well as at the center, a condition is produced wherein the contact area of the cylinder will have a slightly waved surface with three low points one at each end and one in the center, but the amount of deflection at the 10W points is so slight that the resulting surface is practically straight. Y

When properly proportioned, it is practical to construct a cylinder I5" in diameter having a printing surface lsix feet long, and wherein the Variation between the high and low surfaces referred to will not exceed approximately .001" .under` operating conditions; whereas in cylinders vo-f the conventional type, the deflection at the center'would beat least .007". Furthermore, a printing cylinder made in accordance with the invention will weigh but approximately 60% of the weight of one of the conventional type.

It is the principal object therefore, of this invention, to provide a cast cylinder structure, which Vwhen subjected to a pressure equally distributed along-its length as under normal operating conditions, will be deflected both at its centerand at itsends, in a manner' that will tend to'produce a substantially straight Vor undistorted surface.

It is a further object to provide a cylinder structure which has an inner supporting member preferably cast integral therewith along its central circumferential area and having journals at the ends of said supportingfmember.

It is also an object of the invention to provide 5 a cast cylinder of generally improved construction, whereby the device will be simple, light, durable and inexpensive in construction, as well as convenient, practical, serviceable and eicient 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. l5

The preferred embodiment of the invention is illustrated in the accompanying drawing, where- 1n:

Figure 1 is a side elevational View of a portion of a typical rotary intaglio printing machine to which a. printing cylinder of the type herein disclosed is especially adapted;

Figure 2 is a vertical longitudinal section through a printing cylinder;

Figure 3 is an end elevational view with part 25 broken away, looking in the direction of the arrow 3 of Figure 2; and

Figure 4 is a fragmentary sectional detail showing a modified form of structure with a journal formed as a part of the inner supporting member, and also a modified form of covering for the cylinder ends.

In Figure l, a rotary intaglio printing machine is shown in which a printing cylinder Il, of the improved type herein disclosed, is mounted. An impression roller I2 is mounted above the printing cylinder Il and is arranged to apply a substantial pressureagainst the web W running between the said cylinder and roller, according to the usual practice in printing machines of this type. It is due to the pressure of the impression roller that the printing cylinder is deflected during the printing machine operation.

The detail of the cylinder structure, best shown in Figure 2, comprises an outer cylindrical shell v I3 and a supporting member or inner shell I4,

with said inner member preferably cast integrally `with the outer shell along a central circumferential area l5 to thus provide a reinforced centrally supported area on the outer shell and a non-sup 50 ported area at each end thereof. The two ends `lli-I6 of the supporting member, which extend beyond each end `of the integral orV reinforced area, preferably converge inward to a form of truncated cone, and as shown, each has a uted lis if these journals 2 I-2I are supported in suitable bearings not shown, the supporting member l Will be supported by the bearings, While the router shell I 3 will be supported by the supporting member along a central circumferential area.v It will befurther observed that the opposite ends -of the outer shell Will overhang the ends of the supporting member and are thus free tolbe deflected.

When there is an evenly distributed load on Y the cylinder structure, as for example When another cylinder such 4as the impression cylinder i12,

Eigme' 1', is in operati-ve engagement with theV cylindrical shell of the cylinder structure '.I l., a deilection at the center fof the contact area will occur, but theoverhanging-.ends of the outer Vshell will also `be deflected. Therefore, although there is za deflection .a-t the center of the cylinder structure, vthe deflection at theendsoi the outer shell Will oifsetltihe central deectionand Yprod-ucea slightly waved surface along the longitudinal contact area thereof. But, While `the (said contact area :is :actually wavy the difference sbetvveen .the 10W and high Wavel surfaces will loe;so slight ithat the `resulting Vsurface will :be substantially flat. It will be noted thatthe inner section or shell 1'4, herein comprising the vSomewhat thickened Wall central rarea 1.5 of the shell or outer section I3 and the truncated cone shaped ends I6, forms a longitudinally extending `reinforcing truss .or arch for the outer seotionof the shell which may be .considered as being supported cantilever-Wise and that the natural tendency :of theouter sec- .tion to bendWillf-belopposedby this archedls'tructure.

g When the ycasting mouldis .prepared previous to oastingithe .cylinder .structure shown in Figure A2,

' suitable cores are arranged to provide 'the center cavity .28 :and :also the .end .cavities 26a 'between the .supporting member :and .the .outer shell, the ,cores fbeing .properly positioned by supports which form fthe `opening-s 24 :in the supporting member.

When the casting is completed, the ends of the supporting member, Azp1.eviously referred to as the filuted flangeill, are preferably joined with the fendsof the router :shell Eby ribs lorarms as `car-1 be visualized from Figure i3., ibut said arms are later out :to therebyseparate fthe ends of the :supporting amemberffrom the .cuter shell.' When said :arms .are cut, 'the ends .fof the supporting `member fare Vprovided with sa iiuted flanged portion, while ztheends of fthe Avouter 'shell are provided with .a series-of .angularly spaced lugs, indicated at 28.

Inpreparation-o'f dorm vcylinders vused in rotary ntaglio :printing machines, .it is necessary Y,to roiraitethem in .an reledtro -plating bath to deposit the metall used for the'zpr'in'ting surfaces. Asv herein disclosed, means :'is provided to close the ends .of -the cylinder structure to 'prevent the electroplatingfsolutionifrom entering the cylinder. `This .means includes .endcover :plates 25, which 'have :central @clearance ropenings therein, and flt Witlrin'thefmallsofthe outer shell I'3. Thecover jplates `are secured :in 'position by means Aof :screws A25|, `which `engage fthe previously described lugs :28 projecting in-ward `from zthe interior yof the .outer shell. The journaled ends of the gudgeons project through the clearance openings 26 in said lcover plates and soft rubber or similar packing "ing and packing V29 may be omittedv if desired.

Iniligure 4, a modified arrangement is shown inv which the journals are formed as an integral part of the vsupporting member, as indicated at'3 I, thus eliminating the gudgeons. A eXible plate or 'covering 32 is alsol shown, secured to a ange 33 :on the outer .shell .I3 and to a flange 34 on y the supporting member I4 to provide a means for covering the open end of the cylinder structure. The plate :may be made of any .elastic material which Willn'ot interfere with the-deflection of the ends :of the Aouter fshell, `and is preferably secured J'hzplazce by rings 35 56., secured by screws 31., '38, thereby providing a tight joint.

yit .can fbfe Vproven mathematically that a cylinder designed :as-herein .disclosed and having anV thickness fat the center .of the .shell twice as .great as the thickness at yeither lend, .and the distance Voverall 'length Yof the fouter shell of '70", a Wall between :linesA and B approximately 20% of .the Y.

total length of the shell, will When'supporjted in bearings approximately :8.6" apart and subjected to .axloa'd tof `5 tons distributed :equally lalong its upperperiphery, he deflected in such manner .that .the .area to which the pressure is applied will not .be distorted fromV astraightsurface to a degree in .excess `o-filill. yAacylinder so .constructed and weighing approximately 'lOQO'lbs .compares very favorably with a .cylinder of conventional design which in :the same material Would weigh 601% s more .and which kwould show a deflection :at Vthe center vof .007 greater than the deflection at the ends when similarly loaded. VFrom Sthese figures, it will be understood that a structure has been provided which is xparticularly well adaptedto printing :cylinder-s 4that `require frequent handling, .as .a Very :material saving in Weight-may be eftected and the structure is such thatwhen subjectedy toloading as encountered in service, there 'is no `appreciable distortion of .the Contact area Y and substantially Yequal pressure :throughout the length of the cylinder is maintained, Whereas with conventional :typesfof cylinders, diihculty is experienced in .obtaining funiformity inthe printing due to the lighter pressure rthat is obtained g at .the mid ,section Kcylinder surface.

It lwill be yunderstood that the inventionv may :be embodied in .other .specic forms `Without Adre- -parting from "the spirit -or 'essential' attributes thereof .and 'it iis therefore desired-that the presen-t embodiment be vconsideredin all respects as illustrative andnot restrictive, reference being 'had to .the :claims Irather Ithan to the foregoing de-w scription to indicate the 'scope of the invention. 65

Y member. "i 1 y 2. In a cylinder structure, an outer shell, an internal supporting structure in the form of a longitudinally extending arch, the central portion of said supporting structure being constituted by a central portion of said outer shell, end portions on said supporting structure projecting towards the ends of the outer shell, and journals formed on said end portions.

3. A reinforced cylinder structure comprising an outer shell and an inner shell, said inner shell being joined to said outer shell and having a central circumferential portion constituted by a central circumferential portion of the outer shell and having its opposite ends converging inwardly toward the axis of said outer shell.

4. In a. cylinder structure, an outer shell, an inner shell formed integral with said outer shell along a common central circumferential area thereof, extended ends on said inner shell free from engagement with the outer shell and having a central bore at each of said ends.

5. In a cylinder structure, an outer shell, an inner shell formed integral with said outer shell along a common central circumferential area thereof, inwardly converging end portions extending an equal distance beyond each end of the said common area, and journals on said extended ends.

6. In a cylinder structure, an outer shell, an inner tubular shell formed integral with said outer shell along a central circumferential area thereof, an inwardly converging end portion on said inner shell extending from each end of said common area toward an end of said outer shell, journals formed on said converging ends, a cover plate secured to each end of the outer shell, each cover plate having a clearance opening therein to clear the journals, and a'exible packing sleeve to seal said clearance openings.

7. In a cylinder structure, an outer shell, an inner shell formed integral with said outer shell along a common central circumferential area thereof, a truncated cone shaped end extending from each end of said common area, journals provided at the ends of said truncated cones, and flexible means secured to the ends of both the inner and outer shells to close the ends of the outer shell.

8. In a cylinder structure, a cylindrical shell interiorly supported cantilever-wise by an inner section integral with said shell at its central portion and in the form of an arch extending longitudinally of said cylindrical shell, said arch form being constituted by a central portion of said shell, and truncated cone shaped end portions each extending from an end of said central portion axially toward an end of said shell, with the small end of the cone shape concentric with said shell end.

9. In a cylinder structure, a cylindrical shell interiorly supported cantilever-wise by an inner section integral with said shell at its central portion and in the form of an arch extending longitudinally of said cylindrical shell, said arch form -being constituted by a central portion of said shell, and truncated cone shaped end portions each extending from an end of said central portion axially toward an end of said shell with the small end of the cone shape concentric with said shell end, and means at the small end of each of said cone shaped end portions adapted to rotatably support said shell.

10. In a cylinder structure, a cylindrical shell interiorly supported cantilever-wise by an inner section integral with said shell at its central portion and in the form of an arch extending longitudinally of said cylindrical shell, said arch form being constituted by a central portion of said shell, and truncated cone shaped end portions each extending from an end of said central portion axially toward an end of said shell with the small end of the cone shape concentric with said shell end, a member secured to the small end of each of said cone shaped end portions for rotat- 5 ably supporting said shell, said members extending beyond the end of said shell, and a disc secured at its periphery to each end of said shell and through which said member protrudes.

11. In a cylinder structure, a cylindrical shell supported cantilever-wise by an inner section in the form of an arch extending longitudinally of said shell, said arch form having end portions converging inwardly and extending axially of said shell, and a common central cylindrical portion for said shell and the arch form of said inner section.

12. In a cylinder structure, a cylindrical shell having a centrally disposed thickened wall portion, said shell being supported cantilever-wise by an inner section in the form of an arch extending longitudinally of said shell, said arch form having end portions converging inwardly and extending axially of said shell, said central thickened wall portion of said shell forming a central portion for said inner section from the ends of which said converging end portions extend.

ALBERT J. HORTON.

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