US1531478A - Method of making bas-reliefs - Google Patents

Description

B. DIEFENBACH METHOD OF MAKING BAS RELIEFS F1106 April 4, 1924 Patented Mar. 31, 1925.

UNITED STATES PATENT OFFICE.

or BUFFALO, neon AND JAMES D. CAMPBELL, on

NEW YORK, BUFFALO, NEW YORK, A PARTNERSHIP, DOING BUSINESS UNDER THE FIRM NAME OF BUFFALO EV'ERLASTING DISPLAY COM- IPAN Y.

METHOD or MAKING IRAS-BELIEFS.

Application filed April 4, 1924. Serial No. 704,273.

To all whom it may concern:

Be it known that I, BERNHARD DIEFEN- BACH, a citizen of the Republic of Germany, who has signified his intention of becom- 6 ing a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Methods of Making Bas-Reliefs, of which the following is a 10 specification.

The object of the invention isto enable portions of one side of a plate of glass, metal and other material, to be removed by the action of a sand blast in such manner as to economically and rapidly produce a has-relief of more or less intricate design.

A particular objectis to enable portions of one of the layers of a sheet of cameo glass to be quickly,

removed by a sand blast, in such manner as to convert the sheet into a cameo having any desired design and adapted to be used for various purposes, and particularly as an advertising sign, which is clearly legible either by reflected light, or by light transmitted through the cameo.

This object is attainedby the improved method hereinafter described and claimed.

f the accompanying drawings forming a part of this specification,

Figure 1 shows in perspective, a portion of a sheet of'cameo glass.

Figure 2 is section on line 2-2 of Figure 1. I

Figure 3 is a view similar to Figure 1, showing a coating of sensitized paste formed on one of the layers of the glass.

Figure 4 is a sectiononline 44 of Figure 3. e

Figure 5 isa side view; and

accurately and economically.

' form a letter 17,

Figure 6 an edge view of a portion of th I Figure 13 is a view similar to Figure 12,

showing the completed bas-relief after the removal of the hardened portions of the sensitized coating."

The same reference characters indicate the same parts in all of the figures.

In practising the improved method, as illustrated by Figures 1 to 10, a sheet of cameo glass is treated as next described, the sheet being of so-called flash glass, and including a body layer 12, preferably of opal glass, and a facing layer 13 of lass of any desired color, flashed on the ody layer, the color of the facing layer contrasting with that of the body layer. One of the layers, preferably the facing layer, isprovided with a coating 14, of sensitized paste, which is adherent to glass, is quickly soluble, and is adapted to be rendered more slowly soluble by the action of light.

To the coating 14 is applied a pattern composed of a sheet 15 of thin paper, or other b ht-transmitting material, and a design ormed thereon by India ink, or other material, which is subsequently opaque when a plied to the sheet. In the example here s own, the opaque material is designated by 16, and is arranged to and border being on light-transmitting portions of the sheet. 4

The design may be of any desired character, and may be more or less intricate. The pattern ispreferably caused to adhere to {he coating 14 by the adhesiveness of the atter.

and a border 18, said letter The assemblage as shown in section by I Figure 7, is next'subjected to the action of light, either s'olar Ur artificial, the direction of the light being as indicated by the arrow m (Figure 7). 'The light passing through the light-transmitting portlons' of the pattern hardens the portions of the sensitized coating not protected by the opaque portions of the pattern, the portions of the coating thus protected being quickly soluble-by a solvent such as cold water. The lighthardened portions of the coating are in v soluble in cold water, and are solubl gin a different solvent, as, hereinafter described. For convenience, I call these portions the hardened portions of the coating, and the others the quickly soluble portions.

The pattern and the quickly soluble portions of the coating are next removed'by washing, and preferably by submerging the entire assemblage in a bath of cold water, until the pattern is detached and the said soluble portions are dissolved.

A sand blast is then directed, in the direction indicated by. the arrow 3 in Figure 8, against the now partially protected glass layer and the hardened portions of the coating 14 remaining thereon, until the exposed portions of said layer are removed and the corresponding portions of the other layer denuded, as shown by Figure 9, other portions of the partially protected glass layer being left intact.

The glass is thus converted into a cameo having relief portions 17 and 18, corresponding to the portions 17 and 18 of the pattern, as indicated by Figure 10.

After the application of the sand blast, the hardened portions of the coating may be remoyed, in any suitable manner, as by immersing the assemblage in a bath of hot water containing ammonia, this bath constituting a solvent of the hardened portions of the coating, which is thus dissolved and removed.

It isobvious that either of the glass layers may be the layer which is acted onby the sand blast. The sensitized paste may be composed of .bichromate of potash, two parts, glycerine seven parts, glue twenty.

ve parts, and water sixty-six parts.

The invention may be practised in making low relief opaque plates sultable for signs and other purposes. 'For example, the sen- I I sitized coating 14 may be applied to one side light through the pattern of a brass sign plate 20 (Figures 11, 12 and 13). After the exposure of the coating to 15, the pattern and the quickly soluble portions of the coating are removed as above described, and the portions of theplate thus exposed are subjected to the action of a sand blast until depressions 21 of the desired depth are formed and the plate becomes a has-relief, after which the hardened portions of the coating are removed as before. The plate 20 may be of any material capable of being cut by a sand blast.'

The method may therefore be practised in making a sign or ofher article which is -a cameo adapted to transmit light and differently color the transmitted light, or is an opaque relief plate. ,It is obvious that, the

pattern may be provided in any suitable way 4 with light-transmitting portions and opaque relief having depressions of considerable portions.

"It is essential for the production of a basexposed side 7 posed surface of said coating,

depth, and conforming accurately to the patside of the plate facing the source of light, so that the light impinges directly on the exposed outer side of the coating, and its hardening actionis uniform from side to side of the coating. The hardened portions of the coating are thus caused to conform accurately to the pattern at each side of the coating, so that the design produced by erosion on the plate also conforms accurately' to the pattern, and is not distorted or changed, as would be the case if the pattern were applied to the side of a glass plate opposite the side having the coating. I

I am aware that it has been heretofore proposed to apply a sensitized coating to one side of a glass plate, and a pattern having opaque and light transmitting portions to the opposite side of the plate, and out of contact with the coating; the light which 1 portions of the coating are enlarged, and the quickly soluble portions correspondingly reduced, in area. Moreover the said plate must be wholly of clear, light-transmitting glass,.-and cannot be either a plate of cameo glass, including a layer which intercepts light, or a wholly opaque metal plate 20.

My improvement is characterized first by the fact that the pattern is applied to the of the coating 14, and secondly, by the fact that the light rays are directed against the exposed side of the pattern, and do not pass through the plate, so that the hardened portions of the coating enable the sand blast to accurately reproduce the design of the pattern in the form of depressions of uniform depth, in the coated surface of the plate.

What I claim is:

1 The herein deseribedimprovement in the method of making a has-relief, which comprises applying a sensitized coating to a plate, positioning a pattern having lighttransmitting and opaque portions adjacent the exposedsurface of the sensitized coating, directing-light onto said coating through the attern, removing the portions of the coatlng which are not affected by the light. and erroding by a sand blast the portion v of the plate surface from which said coating has been removed. A

2. The herein described improvement in the method of making a has-relief which comprises applying a sensitized coating to one of the layers of a cameo-glass plate, positioning a pattern having light transmitting and opaque portions adjacent the exdirecting light onte the zit-t rn and pertions of said writing 1 exposed t erethr'ough, removing the portions of the coating'which are not afiected by the light, and cutting through the layers of the I 5 plate to which theeoetin'g is appliedin conformity with thenutlines off the. portions from which the coatinghas been removed,

, a 10 affixed 'my- '-i BERNHARD DIEFENBACH'.

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