US2459266A - Article for reproducing drawings on blanks - Google Patents

Description

Jan. 18, 1949. 2,459,266

ARTICLE FOR REPRODUCING DRAWINGS-ON BLANKS Original Filed July 8, 1941 INVEN TOR.

[Maggie 13 frame BY Patented Jan. 18, 1949 ARTICLE FOR REPRODUCING DRAWINGS 0N BIANKS George B. Crouse, Wading River, N. Y., assignor,

by mesne assignments, to Photo-Positive Corporation, New York, N. Y., a. corporation of New York Original application July 8, 1941, Serial No. 401,440. Divided and this application August 30, 1944, Serial-No. 551,929

4 Claims. (01. 958) The present invention relates particularly to an improved article for reproducing drawings on blanks to facilitate their manufacture into various articles.

This is a division of my application Serial No. 401,440 filed July 8, 1941, now Patent No. 2,372,767 of April 3, 1945.

The time required for making accurate scale drawings of parts for airplanes and other equipment occasions delays in the manufacture thereof and increases their cost. The present invention is a simplification of the methods heretofore used to reduce the time required for and the cost of reproducing the drawings on blanks for templates and the like. Heretofore, the general practice has been to make scale drawings on the drafting board first and'thereafter to copy over manually the scale drawings onto the template or other part to be manufactured. The time required is substantial and the chances of errors increase with the complication of the drawings, requiring numerous checking operations. In spite of all precautions, some errors are overlooked resulting in additional cost and loss of time in remaking parts and drawings.

The present invention aims to overcome or minimize the above and other objections and difiiculties by providing an improved, relatively simple means and method for transferring reproductions of drawings to blanks adapted to be used for making templates, patterns and the like An object of the present invention is to reduce the time required for providing accurate scale drawings on blanks for templates and other parts to be manufactured.

Another object of the invention is to simplify the manufacture of airplane parts.

Another object of the invention is to provide an improved article for use in the method.

a laminated light-sensitive sheet of particular use in practicing the method.

Another object of the invention is to provide a simple article which eliminates errors in the transfer of original scale drawings to a template or the like without impairing in the reproduction the accuracy of the dimensions in the original scale drawings.

Another object of the invention is toprovide a light-sensitive film having a reinforcing backing adapted to retain the dimensional characteristics thereof during exposure and adapted to be removed after the exposed film isapplied to a blank for a template.

Other and further objects of the invention'will be obvious upon an understanding of the'illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein-will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the inventionhas been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein Fig. 1 is a perspective view of a=simple drawing on a rigid backing which prevents any material variations in the dimensions thereof; 1 l v Fig. 2 is a perspective view of the preferred embodiment of light-sensitive material for use in the method; I

Fig. 2a is a fragmentary sectional view greatly enlarged and exaggerated to show the type and character of the laminations of the composite sheet shown in Fig. 2.-

Fig. 3 is a diagrammatic view showing the exposure of the light-sensitive material toreproduce the drawing of Fig. 1 thereon.

. Fig. 4 is a perspective view showing the" exposed sheet of Fig. 2 adhered to atemplate'with the 1 reinforcing backing being removed-:-

Fig. 4a is an exploded view of the composite sheet of Fig. 2 adhered to a template with-the reinforcing backing removed.

Fig. 5 is a fragmentary sectional view illustrating another embodiment of light-sensitive material. w 1" Referring again to the drawings'andmore partlcularly to Fig. 1, there is shown. abacking 0f metal, glass or other suitable rigid material. A

. lacquer or other coating 2 is preferably; applied-to one surface of the backing to facilitate the mak- Another object of the invention is to provide ing of a drawing 4 thereon. Paper secured to the backing by a suitable adhesive gives excellent results, but a lacquer or other coating may be-utilized. The drawingl is" accurately made to scale so that it may begreproduced on a-blank and a template or other device made therefrombycutting along the lines of the drawing. Heretofore it has been customary for a draftsman to-reproduce with the usualv draftingminstruments; the drawing shown in Fig. 1 on the surface of a-tem- .plate blank. Thereaftenthe drawinghadto be checked. to avoid errors; the, .template was then f. formed by cutting away those portions; indicated "on the drawing. Thedrawing. must be made accurately .to' scale on the template in order -to i eY -ih ee i Prate e aid. a a-i ha l in Fig. 1 onto the template blanlgshowninfi the rivet holes and other irregularities accurately in position to fit with cooperating parts in the manufacture of the airplane or machine. In additi n. -as parate; z w s t b ad on template blanks. ion each template required;

The present method contemplates the reproduction photographically of the drawing shown.

i 4 without material distortion of any 'ofthesq l jqdi portions. In doing this, applicant provides a light-sensitive sheet of material:dshownigenerally in Fig. 2 and shown in detail" i-nl ii'g. Zw. The preferred embodiment of material comprises a sheet "of relatively tough, smooth paper 6 coated with superimposed layers of; a moisture resisting and water insoluble lacquer I, a lightesensitiye emulsion 3 of any suitable composition, for ax ample, a gelatin-silver halide emulsion, angl a 1 protective layer or bonding layer B which may be made of collodion or a similar material.

Preferably the layer 'wformsa water resistant surface overthe emulsion. The protective or bonding layer 8= may be omit-ted in certain instances but itsuse ispreferred as the light sensitive layer is thus enclosed between waterproof or water resistant layers. This-prolongs; the life of the light-sensitive layen; I

In order to reproduce the drawing on the lightsensitive material shown in Figs. 2 and 2a; the

sensitiive emulsion 3",fa contactprint is obtained which must be accurate in all; details. I?! the backing I for the drawing 4 of'Fl'g. 1 is; made of orother transparent or; translucent material; the light- Himay' Toe-placed under the backing I to allow lightrays-to pass through the djrawmgr in obtaining a photographic reproduction on thought-sensitive materiali.

Preferably; the" atmosphere in the room where the exposure is made and where the light s'nsitivematerial-is kept; is air-conditioned tQ-avoid' any contraction oreirpansion thereof. In order to guard 'airthaagamst contraction and err-pan siong the light-sensitive material is applie'd te the template blank immediately after exposure; a1-

l'owin'g'asamen-areas reasonablypossible for any changes to take place. In order to effect this transf ei' thetemplate blank, guide or pattern I shown in'vE-igs. 41 and 4dis provided with an adhes'ive coating I 2 which preferably is" ofthe type described hereinafter- Thought-sensitive rnate+ rial is ap lie to the template H with thej'pro- 't'ectiv'e; or bonding surface fi 'fa'eing downwardly in contact with the'adhesive t2. Suitable heat a vacuum pad; su'c'l'i asthat illustrated in Fig. 9: of my priorapplication identified above may be utilihed in: securing-- the two together. Thereafiterth paper 6 is stripped offand carries with it lacquercoating' 1, as shown more particuany in Fig: 40;. Thest lfippi'ng ofi of the paper leaves the light=sensitive emulsionexposed; and

a e u bathe template H, s nce the template.

was. of; tem le bl k. h iiul t izeon maybe processed and-developed to reproduce the drawing 4 thereon. Since the processing operations, which require the use of liquids, are

done after the light-sensitive material is secured to thetemplate blanle; distortion is. minimized or completely preventedl Since the reproduction is made while the drawing and light-sensitive sheet of material are in contact, there is no opportunity for distortion in the reproducing operation. have to be measured. Hence, the usual errors'of nhoteesan r ar void Wghile the preferred embodiment where the drawings are to. be reproduced on a template blank, it is preferred to apply theadhesive coat- IJ, tothe template surface, the adhesive coatingma be, applied to the lightsensitive mate- $18 1.; :4 5; illustrates the coating ita so applied. Thalight-sensitive material is identical with that shown in Fig. 2a, except added onto the bonding layer 8. When the lightsensitive'mat'er-ial is appliedto the-template blank.

" thepapen 6 and the lacquer coating 1' are stripped off the same manner as shownrin Fig. 4a.

By applying adhesive to the metal plate or template-blank'asshown in; Figs. 4 and Ema-coating. maybe-utilized which is permanently tacky.- This I will permit the light-sensitive materialto' beadhered-or bonded. to. the template blank in a vacuum anothersuitable place without the application of h'eat. While this construction is not as desirable as one bonded with heat, itis simpler and gives satisfactory results for many purposes.

The adhesive used on the template blank ll should meet certain requirements. The adhesive should retain its; properties when subjected to. the action. of" processing. solutions and the bond formed thereby shouldfbe strong enough to withstand the stresses. set up by the wetting. The

adhesive also should soften at a relatively low temperaturewhen the paper or a light-sensitive emulsion is applied in order to avoid using tem-' peratures sufficiently high to impair the light.

In addition, the adhesive sensitive emulsion.

' should not soften at the temperatures createdin the metal plate by machining and grinding o alations. The latter may run up as high as 475 degreesEahrenheit. The preferred embodiment of adhesive utilizes a thermo-plastic adhesive whose softening point increases after the first applicationotheah This result may be achieved lay-adding to the-adhesive a volatile plasticizer which will not be appreciably volatilized by the temperature of the air used to remove the coating solvents.

The presence of the plasticizer serves to lower the soitening point of the plastic at the first heating,

where a substantial portion of the plasticizer-wlll be, volattlized: so that, thereafter, a temperature substantially higher, such as 475 degrees Fahren- 'heitwi-tl be required to soften the material. While there is no intention of limiting the invention to thepartic'ularexamples given; the following two examples will be illustrative First, six parts of polyvinyl acetate (medium viscosity) thirty parts me'tha1 1fo1 and one part diethylene glycol mono butyl'ethe'ry second, six parts polyvinyl acetate (medium viscosity), thirty parts toluene and one 7 part phenol formaldehyde resin of the thermoover h sett ing type. The above adhesive may be applied to the paper by any desired method or it may be appliedto the metal blank by flowing it evenly Airf re a ddrri s.

Bag-utilizing a vacuum press such as shown in Fig. 9-. of said; prior 'application it is possible to apply thesheet of material to template blank without wrinkles in it. In this way, a smooth No lenses are required and no distances that the adhesive ViZcL is surface is obtained which avoids any irregularities in the finished reproduced drawing.

In the operation of the method, the draftsman first makes a scale drawing on a surface 2 on a backing l. Thereafter the light-sensitive material shown in Figs. 2 and 2a is applied with the protective or bonding layer adjacent the drawing and with the paper 6 at the side remote from the drawing. A contact print is made by reflex printing or by having the backing plate I made of a transparent material and allowing the light rays to pass through it. If desired, a type of emulsion may be utilized which produces a positive instead of a negative in the reflex printing. Immediately after the exposure the light-sensitive material is adhered to the template blank II by the adhesive l2, preferably by utilizing a vacuum a press such as illustrated in my prior application.

The paper 6 and the lacquer coating 1 are then stripped off from the emulsion, leaving the emulsion and the bonding layer adhered to the template blank I I, through the intermediation of the adhesive I2. The emulsion is thus held firmly in place against distortion of any kind and is ready to be subjected to the processing, developing and fixing solutions, after which the drawing 4 will be reproduced accurately on the template. The template blank then may be cut away or ground away, using the reproduced drawing as a guide, in order to produce a finished template.

It will be seen that the present invention provides an improved method of reproducing drawings on template blanks without loss of accuracy and in minimum time. A single sheet of lightsensitive paper is sufficient to transfer a drawing onto a template blank. Since the exposed lightsensitive material is turned over, the reproduction of the drawing which appears on the template blank is not a reversed or mirror image but an actual positive reproduction of the original drawing. By using a suitable emulsion, the black and white may likewise be reproduced as upon the original drawings without being reproduced as negatives, although in most cases the reverse of the black and white portions are not objectionable. The reproduction is done without lenses by having the surfaces in actual contact which increases the accuracy and simplifies the operation. The final reproduction is adhered to the template with an adhesive capable of withstanding the high temperatures to which it may be subjected. The present method simplifies the operations of the methods used heretofore and has unusual advantages with various types of work. Sheets of the preferred or modified material which carry the light-sensitive layer may be readily cut, packed and stored, or the material may be supplied in rolls. It is not necessary to take any extraordinary precautions in exposing the light-sensitive layer carried by the material.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A composite transfer sheet comprising in combination a bottom base sheet of paper; a sheet of photo-sensitive emulsion coated on the upper face of said base sheet; a coating of nitrocellulose on the upper face of said emulsion; and a top layer of thermoplastic substantially transparent adhesive on the upper face of the nitrocellulose coating, said nitro-cellulose coating acting as a bonding between the adhesive and emulsion and permitting the emulsion to be activated by light falling on the top layer.

2. A composite laminated transfer sheet comprising in combination a bottom base sheet of paper; a surface coating of water resistant material thereon; a sheet of photosensitive emulsion coated on the upper coated face of said base sheet; a coating of nitro-cellulose on the upper face of said emulsion; and a top layer of thermoplastic substantially transparent adhesive on the upper face of the nitro-cellulose coating, said nitrocellulose coating acting as a bonding between the adhesive and emulsion and permitting the emulsion to be activated by light falling on the top layer, the adhesion of the emulsion to the water resistant coating being less than that between any two other laminations in the transfer sheet.

3. A complete transfer sheet comprising, in combination, a bottom base sheet of paper; a flexible waterproof pellicle thereon; a sheet of photosensitive emulsion coated on the upper face of said pellicle; a coating of nitrocellulose on the upper face of said emulsion; and a top layer of thermoplastic substantially transparent adhesive on the upper fact of the nitrocellulose coating, said nitrocellulose coating acting as a bonding between the adhesive and emulsion and permitting the emulsion to be activated by light falling on the top layer, the pellicle being secured more tightly to the the base sheet than to the emulsion and less tightly to the emulsion than said bonding is to the emulsion and the adhesive, the pellicle and bonding resisting the entrance of moisture into the emulsion and thus reducing swelling and curling.

4. A transfer sheet as in claim 3 said pellicle being of lacquer.

GEORGE B. CROUSE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 728,245 Krayn May 19, 1903 770,421 Derepas Sept. 20, 1904 1,450,067 Egashira May 27, 1923 1,517,049 Christensen Nov. 25, 1924 1,762,935 Sheppard et al. June 10, 1930 1,911,955 Heinecke et al May 30, 1933 2,000,528 Linderman May 7, 1935 2,010,188 Hagedorn et a1 Aug. 6, 1935 2,090,016 Young et al. Aug. 17, 1937 2,119,724 Staud June 7, 1938 2,143,791 Nadeau Jan. 10, 1939 2,173,480 Jung Sept. 19, 1939 2,182,814 Marasco Dec. 12, 1939 2,275,617 Duerr et a1. Mar. 10, 1942 FOREIGN PATENTS Number Country Date 418,976 Great Britain Nov. 5, 1934 424,976 Great Britain Mar. 6, 1935 450,220 Great Britain July 10, 1936 482,204 Great Britain Mar. 24, 1938

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