US2972533A

US2972533A - Photo-mechanical method of producing technical drawings and the like

Info

Publication number: US2972533A
Application number: US551644A
Authority: US
Inventors: Louis G Frankau; Arthur F Pisacane
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1955-12-07
Filing date: 1955-12-07
Publication date: 1961-02-21
Anticipated expiration: 1978-02-21

Description

Feb. 21, 1961 L. G. FRANKAU ETAL 2,972,533 PHOTO-MECHANICAL METHOD OF PRODUCING TECHNICAL DRAWINGS AND THE LIKE Filed Dec. 7, '1955 2 Sheets-Sheet 1 LAYS L06.

Inventors Louis 6. Frankau, Arthur P Pisacane, b m

The Attor'neg.

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Feb. 21, 1961 Filed D90. 7, 1955 L. G. FRANKAU ET'AL 2,972,533 PHOTO-MECHANICAL METHOD OF PRODUCING TECHNICAL DRAWINGS AND THE LIKE 2 Sheets-Sheet 2 Fig.3.

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I I Louis GfFra'nkau,

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States Paten PHOTO-MECHANICAL METHOD or PRODUCING TECHNICAL DRAWINGS AND THEVLIKE' Louis G. Frankau, Upper Darby, and Arthur F. Pisacane, Landsdowne, Pan, assignors to Genera! Electric Company, a corporation-of New York Filed Dec. 7,-195'5, Ser. No. 551,644

4 Claims. (Cl. 96-.'43)

This invention relates to a photo-mechanicalmethodof producing technical drawings and the like.

Frequently, the drawings which are used in certain technical fields contain a large number of standard symbols and components which appear repetitively. in different drawings, though in varying locations and combinations.

One approach toward reducing the time required forduplicating these various standard symbols on each different drawing has involved preparing a group of appliqucs, or overlays, which individually depict. various symbols,

and then attaching these overlays in their proper locations Accordingly, an object of our invention is toprovide,

for the purpose of producing technical drawings and the like, a new and improved overlay method in which the various overlays used in practicing the method can be applied accurately and rapidly by a relativelyfunskil led person. i

Another important factor in determining the success of such a method is whether the final drawings, or prints,

conform to the high standard of quality which is gen erally required. In this connection, it has been fou'nd that where the format sheet, as well as theattached overlays, contains printed matter, -it is difficult to ohtain fa sharp and dense reproduction of all of the printed matter.

For example, in prior overlay methods where conventional contact reproduction procedures were used, those image lines on the final print which were derived from the overlays sometimes appeared blurred and 'consider-. ably thinner than corresponding image lines derived from the format sheet.

Accordingly, another object of our invention is to assure that those image lines on the final print which are derived from the overlays are dense and sharp andof substantially the same thickness as corresponding lines derived from the format sheet.

Another object is to provide an overlay method which readily lends itself to the use of reusable components which can be easily identified by markings which do not appear on the final print. i

In carrying out our invention in one form, the fol low-' ing components are first provided: (1) at least one transparent format sheet containing certain basic illustrative material, (2) a plurality of different transparent overlays each containing certain additional illustrative material, such as device symbols, (3) a location index sheetco utaining coded indicia coordinated with the format sheet, and (4) a coded instruction form assigning selected overlays to certain locations on the locationindeit sheet.

This instruction form is prepared by an engineer or tech-- nician who is familiar with the subject matter of the proposed drawing, butthe. steps .which.,follow.can be carried, out -by aperson having no such knowledge. Thesesteps are as follows: the transparent format sheet is first superimposed on the location index sheet, which is visible therethrough.'- Then, using the location index sheet as a guide, selected overlays are attached to the format-.isheet in, locations assigned by the coded instruction form. When all, of the required overlays are attached to theformatsheetin their proper locations, the format sheet withthe overlays attached thereto is, removed from the location index sheet and used as apositivefrom which prints are. made by any suitable conventional methodlof reproduction.

in the preferred form of our invention, both the, format sheet and the overlays comprise sheets of positive film having their. printedmatter formed'in a photographicallydeveloped coating on. one side of the film. The printed matter on. the format sheet is off such a nature that it is positively readable from the coating side of the format sheet, but the printed matter on each of the overlays is of. such. a naturethat it is reversely readablefrom the coating sideof the overlay. The overlays are attachedv to the format sheet with their respective coatings in contact with the. coating side of the format sheet, thus producinga composite positive film transparency which is positively readable from the coating side of format sheet.

Used thereafter in a conventional contact-type photo-me chanical reproduction process, this compositelends itself in a very effective'manner to the production of prints having sharp, 'dense lines of consistent thickness. This is the case because the images onboth the overlays and the format'are in substantially the same plane and are errposed through onlya single thickness'of filmduringthe I reproduction process.

For atbetter understanding Of'our invention,' -reference may bel hadto the following specificationtaken in connection with the accompanying drawing in'which Figs. let-through 1d illustrate certainbasic components which are used in practicing the method of our invention; Figs. 2 through 5 illustrate the various steps which constitute the method and which utilize the components of Figs. 11; through It! and Fig. 6 is an enlarged cross-sectional View taken 'along the line. 6--6 of Fig.5 and showing certain of the-components in assembled relationship.

Referring now to Figs.- la through I'd, the basic components shown therein for practicing the'fmethod of the present "invention comprise a location indexsheet 10, a format sheet'll, a'plur'ality of overlays 12, and acoded instruction form 13.

The format sheet ll is a transparent sheet of positive film having printed thereon certain basic illustrative matter which it is desired should appear in the final drawing. Thisbasic illustrative matter is of such a nature that it appears unchanged in all of the various drawings which it'might be desired to make from these components.

The overlays 12, which are shown in an enlarged form in Fig. 1c, are also transparent sheets of positive film and have printed thereon certain standard symbols representing components which it is desired to depict in the parent sheet of film. Printed ,on this index sheet 10 is certain indicia which is subsequently utilized, aswill soon appear, to provide a guide for locating the over lays lz'on'the format 11. This indicia ma take any i suitable form, .butfor illustrative purposes, we have shown the indicia as comprising a series of blocks, each identified by one of a series of letters.

The engineer or technician who is seeking the drawing first determines that certain devices, which are individually depicted by the various overlays, should be-used at certain locations on the drawing. He then refers to the location index sheet and assigns the selected overlays to particular locations selected on the location index sheet. This selection process is recorded on the coded instruction form in any suitable predetermined manner, as forexample, by filling in adjacent spaces on the form with the identifying letter of a particular location block and the number of the overlay selected therefor, as shown in Fig. 1d.

This coded information form is then referred-tea clerk, who need have no knowledge of the subject matter of the proposed drawing. In accordance with our invention, the clerk first tapes the location index sheet 10 to a suitable working surface, such as the top of a light table 15, as shown in Fig. 2. The format sheet 11 is then superimposed upon the location index sheet and taped in place in a predetermined position thereon, as is shown in Fig. 3. Correct positioning of the format sheet is achieved preferably .by bringing into registry certain preselected marks, such as the frames on the two sheets;

Then, the clerk selects the various overlays designated on the coded instruction form and attachs these overlays, as by transparent .tape, to the format sheet in the locations specified by the instruction form. The location index sheet is, of course, .visible through the translucent format sheet 11 and accordingly serves as a guide for achieving precise location of the various overlays on the format sheet. Fig. 4 shows the format sheet after some of the overlayshave been attached thereto, When all'of the required overlays are attached to'thef format sheets in their proper locations, the format sheet with its overlays is thenremoved from the location index sheet, as is shown in Fig, 5. This composite, i.e., the positive format sheet having the positive overlays attached thereto, subsequently serves as a positive from which prints are produced by any suitable conventional contact-type photo-mechanical reproduction method.

Preferably, a sheet of translucent autopositive material, such as autopositive paper, is used for each of these final prints. This autopositive paper,rwhich is of a conventional form, has a light sensitive emulsion coating one of its surfaces. In accordance with conventional reproduction procedures, this emulsion on the auto. positive paper is placed in contact with the positive film composite and-is then suitably exposed. Thereafter, the: sheet of autopositive paper is removed from the fi'm, and is suitably developed to produce on its emulsion side an image of theprinted matter on the film. V

The use of positive film overlays hasusually been avoided because the prints obtained by using conventional contact-type reproduction procedures, such as described above, were not of the required high quality. For ex-' ample, we have found with prior overlay methods that those image lines on the final print which were derived from the overlays sometimes appeared blurred and considerably thinner than corresponding image lines derived from the format sheet itself.

To overcome this problem and thereby produce prints having sharp, dense lines of consistent thickness, a novel relationship of the overlays and the'format sheet has been devised. More particularly, the overlays, which are formed of positive film having a photographicallydeveloped coating located on one side, have their printed matter formed in the coating in such-a manner that it is reversely readable when viewed from the coating side. On the other hand, the format sheet, which is also of positive film having a photographically-developed coating located on one side, has its printed matter formed, in the coating in such a manner that it is positively readable from its coating side. In producing the composite 4 film assembly, the overlays are attached to the format sheet with the coating of each of the overlays in contact with the coating side of the format sheet. This relationship is illustrated in Fig. 6, which is a cross-sectional view of a portion of the composite taken along the line 66 of Fig. 5. The overlay 12 of Fig. 6 is shown with its photographically-developed coating 16 in contact with the side of the format sheet 11 having the photographically-developed coating 16 thereon. Since the overlays are attached with their emulsion, or coating side facing the format, the resulting composite is positively readable from the side of the format to which the overlays are attached. In photo-mechanically producing prints from this composite, the composite is positioned with the back, or uncoated, side of the format sheet in contact with the emulsion side of the autopositive paper on which the final print is to be made.

The paper is then exposed and suitably developed, as

previously described. 7

Most advantageous is the fact that, in our composite, the photographically-developed coating of each overlay is in substantially the same plane as the photographicallydeveloped coating of the format sheet, as can be seen in Fig. 6. Hence, during the contact-type photo-mechanical reproduction process described above, all of the images on the composite film are at substantially the same distance from the surface on which the final print is to be made. This assures that the image lines on the final print will be of consistent density and sharpness. The

fact that the images on both the overlays and the format sheet are exposed through only a single thickness of film also contributes to the sharpness and density of the lines on the print.

The fact that our method utilizes positive film overlays containing printed matter of such a nature that it is reversely-readable from the emulsion, or coating, side of the overlays has still another important advantage.

In addition to lending themselves to high quality prints in the manner described above, these overlays also lend themselves, in a highly advantageous manner, to a rapid and simple one-step method of preparation. More particularly, we prepare the overlays from a drawing, prefj erably inked, by superimposing a sheet of clear autopositive film on the drawing with its emulsion, or coated,

side in contact with the inked side of the drawing. The auto-positive film is then suitably exposed, as in a vacuurn-frame, and after being developed contains on its emulsion side a reverse-reading image of the drawing,

- as is desired for the method of our invention. Thus, the

need for intermediate negatives and the steps required to produce such negatives is completely obviated.

Af ter the required number of prints have been made from the above-described composite, it is a simple matter to disassemble the composite and then to file the overlays away for subsequent reuse. To aid in such disassembly, the plastic tape is selected to be of a type which is readily detachable from the surfaces of the film.

To facilitate ordering, filing, and actual use of the various components of our invention, it is desirable that they each be assigned some form of easily distinguishable identification. It has been found that the most practical manner of identifying the components is to apply written or printed identification marks to each component. The,

one problem presented by this manner of identification isthatwritten identification marks applied to the overlaysand the format normally will tend to appear on the final print, along with the other written material on the overlays and format. For obvious reasons, this is generally undesirable.

In those prior methods where negatives, instead of positives, were used, this problem could be easily over-,

come by applying the identification marks to an opaque portion of the negative. With positives, however, there is rarelyan opaque area large enough to accommodate an easily-distinguishable identification mark. We have v l overcome this problem, as it exists with positive films, by applying the'identification marks to the film with a translucent dye of acolor which is visibleto-the naked eye but is transparent to, or transmits, thelight which. is used in the *finalphotomechanical printing process. For: example the color of the translucent dye can be of approximately the same color as" the. color offthellight used in the.finallprintingprocess. In this regard, ,we have found that a translucent yellow dye fsuitably applied to they positivefilm used combination with a yellow exposure light pioduces excellent results. In the final printing process fthe marked region oflthe film be'haves as if there. were no "identification thereon as a result, hese markings do not appear orftlie final print.

Although we have shown only one location index sheet and one format sheet, it is to be understood that any number of these in widely or slightly differing form can be available for use with the overlays shown, as well as with additional overlays not shown, thus providing for a virtually infinite number of possible combinations. In these cases where more than one format sheet-or location index sheet is available, the coded instruction sheet should, of course, specify, as by reference to their above-described identification marks, which ones of these sheets are to be used for the particular drawing that is being prepared. It is also to be understood that the term, transparent, as used throughout this specification to describe the format sheet and the overlays, is intended to comprehend various degrees of translucency. It is to be further understood that the term print, as applied to the final product, is used in its broad sense and is intended to apply not only to final working drawings or copies but also to easily-reproducible type drawings which can, in turn, be relied upon for such final drawings.

While we have shown and described a particular embodiment of our invention, it will be obvious to those skilled in the art that various changes and modifications may be fnade without departing from our invention in its broader aspects and we, therefore, intend in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A method of making technical drawings comprising the following steps: providing a plurality of transparent format sheets having identifying marks thereon and having basic illustrative matter printed thereon, providing location index sheets having identifying marks thereon and having certain areas thereof delineated and positionally coordinated with the printed matteron said format sheets, providing a plurality of transparent overlays which contain additional printed matter depicting components which it is desired to have appear in the final form of said technical drawings and which are adapted to fit over said delineated areas and which are identified with distinctive markings, then preparing a coded instruction form in which distinctive markings of preselected overlays are assigned to preselected areas on said location index sheet, and in which the identifying mark on a preselected format sheet is assigned to the identifying mark on a preselected location index sheet, superimposing said preselected transparent format sheet upon said pre selected location index sheet in a preselected position thereon wherein preselected indicia on said two sheets register thus rendering the delineated areas of said location index sheet visible through said format sheet, removably attaching those overlays designated by said instruction form to the format sheet in locations registering with those delineated areas of the location index sheet specified by said instruction form using the location index sheet as a guide for precise location of the overlays, said attaching step being so performed that said overlays remain attached to said format sheet if said format sheet is su sequ nt y enov dfrbm said. lcca i u index he t.

then removing from the location index sheetthe ,corn

posite comprising the'format sheet an the attached overv a M e r q a a posit v P nt m said a no y, a p om h ical Pr nt g process, which com illustrative matter in a form-that; is: positively readablev from said coating side, said oyerlaysl each comprisingl'a lex b sh ofinosi x l en a ness as the format sheet and liavingon' one of its sides a photographically-developed coating containing said additional printed matter in a form that is reversely readable from the coating side of said overlay, said overlays being attached to said format sheet with their respective coatings in contact with the coating side of said format sheet and with their opposite sides bare.

2. The method of claim 1 wherein said overlays are produced by a printing process which comprises positioning the emulsion side of a transparent sheet of autopositive film in contact with positive-reading illustrative material provided on a sheet of drawing, and thereafter exposing the autopositive fihn to provide on its emulsion side a reverse-readingimage of said illustrative material.

3. The method of claim 1 in which the attached overlays areattached to said format sheet by applying transparent pressure sensitive tape to the overlays and the format sheet.

4. A method of making technical drawings comprising the following steps: providing a plurality of transparent format sheets having identifying marks thereon and having basic illustrative matter printed thereon, providing a plurality of location index sheets having identifying marks thereon and having certain areas thereof delineated and positionally coordinated with the printed matter on said format sheets, providing a plurality of transparent overlays which contain additional printed matter depicting components which it is desired to have appear in the final form of said technical drawings and'which are adapted to fit over said delineated areas and which are identified with distinctive markings, then preparing a coded instruction in which distinctive markings of preselected overlays are assigned to preselected areas on said location index sheet and in which the identifying mark on a preselected format sheet is assigned to the identifying mark on a preselected location index sheet, superimposing said preselected transparent format sheet upon said preselected location index sheet in a preselected position thereon wherein preselected indicia on said two sheets register thus rendering the delineated areas of said location index sheet visible through said format sheet, removably attaching those overlays designated by said instruction form to the format sheet in locations registering with those delineated areas of the location index sheet specified by said instruction form using the location index sheet as a guide for precise location of the overlays, said attaching step being so performed that said overlays remain attached to said format sheet if said format sheet is later removed from said location index sheet, then removing from the. location index sheet the composite comprising the format sheet and the attached overlays, and then producing a positive print from said composite by a photo-mechanical printing process which comprises exposing a sheet of autopositive material while said sheet of material is disposed in contact with said composite, said format sheet being a flexible sheet of positive film having on one of its sides a photographicallydeveloped coating containing said basic printed matter in a form that is positively readable from the overlay receiving side of said format sheet, each of said overlays comprising a flexible sheet of positive film of generally he, e a J the same thickness as the format sheet and having on one of its sides a photographically-developed coating containing said additional printed matter in a form that is r'eversely readable from the coating side of said overlay, said overlays being attached to said format sheet with their respective coatings in contact with said format sheet and with the respective opposite sides of said overlays bare, said photo-mechanical printing process comprising exposing said sheet of auto-positive material with said composite in contact therewith to an exposure light of a predetermined color capable of exposing said autopositive material, said identifying markings for said overlays being applied to the overlays with a'translucent dye of substantially said color which is visible/to the naked eye but transparent to said exposure light, whereby said markings do no appear on the final print. I

References Cited in the file of this'patent UNITED STATES PATENTS.

182,624 Alissoif Sept 26;

980,290 Kubel ,et a1. -.Ian;3," 1911 1,736,445 'Janenga et al Nov; 19', 1929 1,777,144 Innes Sept. 30, '1930 1,896,739 Breslauer Feb. 7, 1933 2,200,203 Heintz Feb. 7,1940 2,369,449 Fallesen Feb. 13, 1945 2,752,245 Hough et al.' June 26, 1956

Claims

1. A METHOD OF MAKING TECHNICAL DRAWINGS COMPRISING THE FOLLOWING STEPS: PROVIDING A PLURALITY OF TRANSPARENT FORMAT SHEETS HAVING IDENTIFYING MARKS THEREON AND HAVING BASIC ILLUSTRATIVE MATTER PRINTED THEREON, PROVIDING LOCATION INDEX SHEETS HAVING IDENTIFYING MARKS THEREON AND HAVING CERTAIN AREAS THEREOF DELINEATED AND POSITIONALLY COORDINATED WITH THE PRINTED MATTER ON SAID FORMAT SHEETS, PROVIDING A PLURALITY OF TRANSPARENT OVERLAYS WHICH CONTAIN ADDITIONAL PRINTED MATTER DEPICTING COMPONENTS WHICH IT IS DESIRED TO HAVE APPEAR IN THE FINAL FORM OF SAID TECHNICAL DRAWINGS AND WHICH ARE IDENTIFIED WITH OVER SAID DELINEATED AREAS AND WHICH ARE IDENTIFIED WITH DISTINCTIVE MARKINGS, THEN PREPARING A CODED INSTRUCTION FORM IN WHICH DISTINCTIVE MARKINGS OF PRESELECTED OVERLAYS ARE ASSIGNED TO PRESELECTED AREAS ON SAID LOCATION INDEX SHEET, AND IN WHICH THE IDENTIFYING MARK ON A PRESELECTED FORMAT SHEET IS ASSIGNED TO THE IDENTIFYING MARK ON A PRESELECTED LOCATION INDEX SHEET, SUPERIMPOSING SAID PRESELECTED TRANSPARENT FORMAT SHEET UPON SAID PRESELECTED LOCATION INDEX SHEET IN A PRESELECTED POSITION THEREON WHEREIN PRESELECTED INDICIA ON SAID TWO SHEETS REGISTER THUS RENDERING THE DELINEATED AREAS OF SAID LOCATION INDEX SHEET VISIBLE THROUGH SAID FORMAT SHEET, REMOVABLY ATTACHING THOSE OVERLAYS DESIGNATED BY SAID INSTRUCTION FORM TO THE FORMAT SHEET IN LOCATIONS REGISTERING WITH THOSE DELINEATED AREAS OF THE LOCATION INDEX SHEET