US2383080A - Method of making curved printing members - Google Patents

Description

21, 1945- F. E. REILLY ETAL 2,383,080

METHOD OF MAKING GURVED PRINTING MEMBERS Filed Sept. 4, 1941 2 Sheets-Sheet 2 lNVENTORS: FRANK E REILLY l) BYCHESTER HOLS/NGER 7 w WW 7% ORNEYS Patented Aug. 21, 1945 and! zsaaosp monormmocunvanrammo MIAMI. .41; I

Chicago, llolainger, llcch'olnphlc m, gearporation, New York, N. Y.;-a corporation of animate September- 4,1941, s ial No. loam 4 Claims. ion-401s) The present invention relates to a novel and improved curved printing member and process of producing the same.

Objects and advantages of the invention will i be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realised and attained by means of the instrumentalities.

alnd combinations pointed out in the appended c aims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together May 20, 1941.

of our prior application Serial No. 394,262.1iled In accordance with the present preferred embodiment of the invention, as lllustratively carried out with copper photoengravings, the ilat', full page photoengraving having, for example, illustrations, line work and text, is preliminarily romd sons to increase the 'depth of the plate in its non-printing areas, exceptin only the large open spaces, or large dead metal areas of the plate. Thereafter, the back of the plate is covered with soldering foil in those areas correspending to the printing portions on the face .with the description, serve to explain the principles of the invention.

Of the drawings- Fig. 1 is a top plan view of a flat printing plate which been partially routed in accordance with the present invention;

Fig. 2 is a fragmentary sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a bottom plan view of the plate shown in Fig. 1, after the soldering foil has been applied to it;

Fig. 4 is a perspective view showing a curved base member used with applicantsinvention;

Fig. 5 is a central cross section of the plate mounting apparatus, most of the parts being shown diagrammatically;

Fig. 6 is a top plan view of a finished plate in accordance with the present invention;

Fig. '7 is an end view of the plate shown in Fi 61 and Fig. 8 is a fragmentary sectional view on "the line 8-8 of Fig. 6. i

The present invention has for its object the provision of a novel and improved curved printing member for letterpress or relief printing. A'funther object of the invention is the provision of a novel and improved process for producing curved letterpress printing members which simpliiies the routing of the plate, insures better register, and results in a plate which can be of the plate. The mu coated plate is then placed with its back against relatively rigid curved base .member, and is "curved so that it conforms to the curvature of the base, after which the plate and base are subjected to heat and pressure causing the plate to be soldered or sweated on to its base. Suitable precautions are taken to insure accurate registration of the plate on its base, and after the sweating has been accomplished, the plate is cooled so that it remains securely aflixed to the base.

. Thereafter, the curved base with the printing plate securely fastened thereon is further routed,

this routing outlining the larger non-printing Y areas of the plate, and being of sufiicient depth so that these large areas of dead metal drop out,

operated at substantially higher press speeds,

produces improved impressions and is subject to little wear. The invention also provides a novel and improved process of routing,- curving and mounting relief printing members, particularly photoengravings, for use on rotary high speed printing presses in the printing of magazines and newspapers.

The present invention is a continuation in part or can be removed from the curved base, as no soldering foil was provided between them and the base. a

The process of the present invention is highly advaiitageous, inasmuch as the outlining and dropping out of the large non-printing areas greatly reduces the time required for the routing of the plate. and the detailed routing of the smaller non-printing areas may be rapidly carried out while the plate is in a flat condition. The non-printing areas serve to support the plate against deformation and distortion while it is being curved, and yet may be rapidly and easily removed after the printing portions of the I plate have been sweated to the base. The finished curved printing members produced in accordance with the present invention are superior to the conventional curved photoengraved plates, due to their greater rigidity, which permits them to be more securely clamped to the printing cylinder and also insures a firmer impression. The process is also advantageous in that the plate is bent before it is seriously weakened by the routing of the large non-printing areas, thereby reducing the distortion in the curved plates.

It will be understood that the foregoing general description and the following detailed description as'well are exemplary and explanatory of the invention but arenot restrictive thereof.

Referring now in detail to the accompanying drawings which illustrate the various steps in the present preferred process, as well as a typical embodiment of the invention, Fig. 1 is a plan view of a partially routed photoengraved copper plate to be a part of a curved printing member. The plate ii is formed with half-tone illustrations ll, text I 2, a portion of line work II, and a rule 14. In addition to the small non-printing areas between the-various lines of text matter, such a plate presents non-printing areas I5 of intermediate size, for example, between columns, between the half-tone portions H and the rule It, and between the various printing portions of line work I3. Additionally, there are other non-printing areas of intermediate size, such as the white portions ll of the large reversed letters. All of these non-printing portions I! of intermediate size, as

well as the much larger non-printing areas It,

must be routed out for satisfactory high-grade printing of the relief plates on a rotary press, and

in Fig. 1, the plate I0 is shown with all of its nonprinting areas l5 routed to lower them well below the printing surface of the plate.

After all of these intermediate non-printing areas It have been routed, and while the plate is still in its normal flat condition, the back of the plate is covered with a suitable flux, and cutout sheets of foil I9 are applied to its back, the general shape and position of the foil II corresponding to the various printing areas, ll, I2, I! and I4, and to the routed out areas I5, but not extending into the large non-printing area l8. In order to secure better adherence of the plate to its base, the back of the plate is preferably buffed before being fluxed, and when sired, the

. plate may be provided with suitable registering holes 2| accurately registering the plate on its base.

Fig. 4 shows a typical and illustrative form of curved base member, and comprises the curved, parti-cylindrical bas 25 formed with beveled edges 26, of. uniform thickness, and of the same general size as the printing plate III. Thi base is preferably formed of centrifugally cast brass and is accurately machined to render its inner and outer surfaces smooth and accurately cylindrical.

The beveled edges 26 are such that they can 1 be engaged by the usual plate clamps on the printing cylinder. Base 25 i also provided with h'oles to register with the holes 2| in the plate,

' thereby accurately locating the photoengraving on its curved base. 7

After the base member has been carefully cleaned and coated with soldering flux on its outer surface, the plate I II is laid thereon and curved to conform generally to the cylindrical base, care being taken not to disturb the sheets of foil I! which are between the back of the plate In and the outer surface of the base 2|. The curve base, and the preliminarily curved plate has been melted to sweat the plate toits base,

Thereafter, cooling fluid is passed through the pipes 38, and the hollow convex member 22 is cooled sufilciently to set the solder and thereby secure the plate In to its base 25,

Suitable pins 38 project through the registering holes 2| and 28, and into registering holes in the members 30 and 32 so as to hold the plate in a definite location on its base during the sweating operation. Thereafter, the plate i removed :from the mounting apparatus, and is ready for further treatment.

The curved printing member is then placed on a curved routing machine, and the large nonprinting areas ii are outlined by the routing tool cutting through the entire thickness of the plate It, thereby freeing these large printing areas of dead metal which dro out or may be otherwise easily removed from the base 25. The marginal portions 20 of the plate may also be removed by cutting through them with the routing tool, thereby removing from the printing member all of the non-printing areas, except the routed areas I! of intermediate size.

The printing member is then ready to be clamped on the cylinder of the printing press in the usual manner, providing an accurate, substantially undistorted, rigid photoengraving capable of yielding high quality impressions.

ill are then placed in the pressure mounting apparatus shown diagrammatically in Fig. 5. This apparatus comprises acylindrically concave shell 30, accurately corresponding to the desired outside curvature of the finished printing member, and a hollow cylindrically convexed pressure member 32, accurately corresponding to the diameter of the-printing cylinder on which the curved printing members are to be-mounted. The mem- In many respects, the invention is applicable to other relatively thin relief or letterpress printing members, and is particularly useful in connecprinting plate, routing out certain non-printing areas, applying soldering foil to the back of the plate, curving the plate, securing the plate by said foil to a rigid curved bas and thereafter cutting through the plate around the large non-printing areas so that these portions may be removed from the curved base.

2. The method of producing curved printing members which comprises preparing a flat, relief printing plate, routing out certain non-printing areas, curving the plate and securing it to a rigid curved base and thereafter cutting through the plate around the large non-printing areas so they may be removed from the base.

3. The method of producing curved printing members which comprises preparing a flat, relief printing plate, routing out certain non-printing areas, curving the plate and securing it to a rigid I around the margins 01' the plate so they may be removed from the base.

4. The method of producing curved printing members which comprises preparing a flat photo- 4 engraving, routing out non-printing portions of intermediate size, applying soldering foil to the back of the plate to areas corresponding to the printing areas of the plate, sweating the plate to a rigid curved base, routing around the large nonprinting areas and through the plate whereby

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