US2040377A - Rubber die - Google Patents

Description

May l2, 1936. Y M. HARLEY 2,040,377

RUBBER DIE Filed Oct. l5, 1934 l o I INVENTOR l0 l2, l l q lo W- BgW///m ATTORN EYAS.

Patented May 12, 1936 PATENT OFFICE RUBBER DIE Lee M. Harley, Brooklyn, N. Y., assignor to James H. Matthews & Company, a corporation of Pennsylvania Application October 15, 1934, Serial No. 748,306 s Claims.` (01.101-379) This invention relates to improvements in rubber printing dies or blocks, and to improvements' in the production of the printing dies or blocks.

The rubber printing dies or blocks to which the improvements apply are dies or blocks shaped in the form of flexible sheets which, after shaping, are mounted on rigid carriers, perhaps planesurfaced, but ordinarily cylindrical. Thus a rocking or rotary printing block is formed, useful, for example, for printing legends upon paper cartons. I cite this particular instance for the use of printing dies or blocks by way of example, and do not exclude from the field of utility many other and varying particular uses.

'I'he invention has to do with the problem of providing dies for the production expeditiously and cheaply of printed cartons and the like, Where the printed matter includes both standard characters, such as letters of the alphabet and numerals, and also characters that are nonstandard and unique, such as trade-marks, for example. The usual practice in preparing dies for the printing of standard characters is to set type in a form and, using the form as a matrix, to make a mold, in which the characters are reproduced in intaglio; and then to shape the rubber die in the mold so formed. When it comes to the preparation of a die for the printing of a non-standard and unique character there are two procedures available: one is to engrave the character (ordinarily in wood) and, using the special wood-cut precisely as the standard type is used, to continue in the manner already described. The other procedure is to prepare a suitable blank die faced with rubber of engravable nature (different n nature from rubber that is used in making a molded die, and not itself moldable) and then to engrave the character in relief upon the face of that blank, in like manner as in the procedure rst described the character is engraved in the block of wood.

When it comes to producing cartons and the like that bear printed upon them matter of mixed nature, including both standard characters and characters that are unique, problems arise, and it is in a solution of those problems that my invention is found.

It is quite possible, of course, to engrave the Whole in the face of a blank die of engravable possible to produce two dies; one a molded die,-

that shall bear the standard character, and the other an engraved die, that shall bear the unique character; and to combine these into one die by afixing the molded die to the engraved die by cementing or other means, but this in many cases is too costly.

My invention is realized in integrating in the substance of a molded die, in the face of which in usual manner the desired standard character is molded, and in the same molding and vulcanizing operation in which the standard character is formed and vulcanized, an inlaid panel of engravable rubber simultaneously vulcanized, whose face shall in the vulcanized sheet extend in common plane with the face of the molded character, and thereafter to engrave in the face of that panel the desired non-standard and unique character.

In the accompanying drawing, Fig. I is a plan view of my composite, flexible die or block, showing a plaque of engraving rubber associated with a molded legend in the die, the plaque of engraving rubber being mounted for engraving, but unengraved.

Fig. II is a. side elevation of the die or block as shown in Figure I.

Fig. III vis a plan View similar to Fig. I, but showing the plaque of engraving rubber actually engraved to provide a particular design.

Fig. IV is a side elevation of the die or block as shown in Fig. HI.

Fig. V is a cross-sectional, exploded viewthrough a mold for making the die and the elements composing the composite die, illustrating a step in the production of my composite rubber die or block.

Fig. VI is a similar view illustrating the molding operation by which the molded legend of the rubber die or block is formed, and the plaque of engraving rubber is integrated with the molded portion of the composite die or block.

Referring particularly to Figs. I to IV, inclusive, of the drawing, reference numeral I designates the rubber base of the die or block, and reference numeral 2 designates portions of a molded legend on said base. vulcanized to the rearward or under face of the rubber base l is a flexible backing element 3, which is desirably of some stout, but flexible, fabric such as a heavy twill.

Fig. I of the drawing shows an unengraved plaque 4 of a grade of rubber suitable for engraving, which plaque is secured by vulcanization to l a layer 5 of friction fabric incorporated in the body of the die. The plaque of engraving rubber has its exposed face, as will be apparent in Fig. II of the drawing, in the approximateplane of the printing faces of the characters 2 which compose the molded legend.

Fig. III illustrates the cutting .of a device 3 of friction fabric 5. As shown, a simpledevice.

has been cut in the plaque of `engraving rubber. Obviously, however, other and more intricate devices may similarly be cut, and, if desired, an additional legend may be applied to the device, or the plaque used solely to carry one of a number of alternative legends, without change in the main die legend yprovided by the molded characters 2.

Figs. V and VI of the drawing illustrate the integration of the plaque for engraving with the remaining elements of the die or block. Referring particularly to the exploded view of Fig. V, reference numeral 'I designates a mold having therein intaglio impressions 8 for the Amolding of the characters 2, and a less specialized inset region or bed 9 for the reception of the engraving rubber to form the plaque l. The bodies which are to form the die or printing block comprise blocks III of molding rubber, which are shown as presented to the intaglio character-forming regions 8 of the mold. It will be noted that these blocks are of substantially greater depth than the mold impressions which are to form the characters,

and that they comprise an excess of material over that required for the characters. A relatively thin body of engraving rubber II is shown as presented to the inset depression or bed defining the plaque for engraving. At the outer face of the body II of engraving rubber there is shown in Fig. V a layer I2 of friction fabric, and beyond that a sheet I3 of molding rubber. Lying between these various elements and a presser plate Il associated with the mold, there is shown the backing sheet I5, which, as mentioned above,

is desirably of some fabric such as a heavy twill.

In integrating the printing die or block, presser plate Il is brought to bear upon the various elements arranged substantially as shown in Fig. V, and an adequately high temperature to flow the molding rubber is supplied to the mold. In this step of actual molding integration, the body II of engraving rubber is pressed into the depression 9. It should be noted that this rubber doesl not readily flow for molding as do the other bodies of rubber incorporated in the die, and it is, therefore, of approximately thesize and shape desired for the plaque" l. As the elements are pressed and heated, body II takes the form of the impression or bed 9, with, however, but little change in its thickness and plan contour. 'Ihe bodies I0 of 'molding rubber, however, are caused not only to fill the intaglio impressions 8, but are also spread to provide the continuous rubber base I of the die, joining and becoming integral with the sheet I3 of rubber which is presented outwardly of the fabric backing I5. As the engraving rubber II is softened to an appreciable extent, the friction fabric -I2 becomes bonded to vits rearward face and is securely bound thereto blocks Il and the rubber of sheet I3 being shown as integrated to provide the continuous rubber base I which secures the printing elements of the die to the flexible backing sheet 3. It should be understood in this connection that the rubber sheet I3, which lies between the special backing 3 of friction fabric for the engraving rubber, and

the fabric of the .backing sheet, may desirably be of a soft rubber which high cementing properties u'nder vulcanization, as the rubber of firmness to the backing fabric, andy also integrates itself along its edges most adequately with the excess rubber from the character blocks III. Clearly, instead of using a free sheet of cementing rubber, such Aas the sheet I3, green rubber of a cementing grade may be spread over all, or a portion, of the fabric backing prior to molding and vulcanization, It has been noted that the body of plaque 4 is relatively thin, and also that lsuch grade both 'secures itself with particular it merely fills the mold impression 3 during inte- 4 grating vulcanizatlon. The engravable rubber of which this plaque is made is recognized generally hardness that it does not to 'an appreciable degreeiiow under vulcanization, although it does so soften as to form a bond. It has 'also been noted that the printing face of the plaque l lies approximately, and effectively, in the plane ofv the printing faces of molded characters 2. Whether the integrating body of rubber lying behind the sheet II which forms the plaque be, as shown, a free sheet I3, or whetherit be, as suggested, a body built up on the backing sheet, it Serves as a build-up, bringing the free face of the plaque into an approximation to the plane of engraving rubber for subsequent engraving,-

to provide an engraved device, an engraved legend additional to the molded legend, or an engraved device bearing an engraved additional legend. I l

The die is completed by the engraving of the panel l of engravable rubber, as diagrammatically indicated in Figs. II and IV.

'Ihe characteristics of a printing die engraved in engravable rubber are different from those of a printing die of moldable rubber shaped in a mold. Essentially, moldable rubber is compounded with the capacity in view of flowing under heat and pressure and filling a mold: engravable rubber is compounded with the capacity in view of lending itself to the cutting operation and affording a solid sharp print. Furthermore, the edge of the character engraved in engravable .rubber is Sculptured from the body of the block:

the edge of the molded character is shaped under pressure. And because of such differences in -condition and circumstance the engraved char- 'in the art as a rubber having such degree of a block of rubber ilowable under vulcanization of volume adequate to form a molded character and to provide an excess for lateral flow, position'.- ing at an adjacent mold cavity a body of 'engravable rubber decient in moldability and having approximately the dimensions of the mold cavity in which it is set, positioning a sheet oi' rubber flowable under vulcanization over said body of engravable rubber and in edge adjacency with said fiowable block, and molding the said assembly under vulcanizing conditions to a ilexible backing sheet, said several rubber elements under the forces for forming a molded character from said flowable block and under the temperature conditions of vulcanizatioli being united to produce with each other and with the flexible backing sheet an integral, flexible, composite die having vulcanized union between the several eiements thereof.

2. The herein described method in accordance l with the procedure of claim 1 comprising additionally integrating into the assembly a backing of friction fabric for limiting the depthof an engraving cut immediately behind the engravable plaque by effecting vulcanized engagement of said friction fabric both to the said engravable plaque and to the said flowablebody of rubber.

3. A composite integrated rubber printing die comprising a flexible backing sheet, a molded character in bonded union with the backing'sheet presenting a printing face spacedfrom the baciing sheet, a plaque of engravable rubber having a thickness less than the thickhess of the said molded character and having bonded union therewith, and an integrating body of rubber sof-ter' than the engravable plaque lying between tlie engravable plaque and, the backing sheet in bonded union with the plaque and with metacring sheet, said engravable plaque as spaced from the backing sheet by said integrating of rubber having its free race lying approximately in common plane with the printing .face of said molded character. v

4. A composite integrated rubber comprising a flexible backing sheet, a molded character in bonded union with the backing sheet, a plaque of engravable rubber in bonded union with the said molded character, an integrating body of rubber lying between the engravablc plaque and the backing sheet in bondedunion with the backing sheet and withthe -molded character, and a backing of friction fabric for limiting an engraving cut to the depth of the engravable plaque in bonded engagement with the said engravable plaque and the said integrating bodyA ,of rubber, the free printing faces of said molded'character and said engravable plaque lying approximately in common plane.

5. A composite integrated rubber printing die comprising a flexible backing sheet, a molded character in bonded union with the backing sheet presenting a printing face spaced from the backingv sheet. a plaque of engravable rubber having 'a thickness less than the thickness of the said lmolded character and having bonded union therewith, an integrating body of rubber softer lthan ,the engravable plaque lying behind the s aid engravable plaquein bonded union with the said backing sheet and with the said molded character, vsaid engravable plaque as spaced from thebacking sheet by said integrating body of rubber having its free face lying approximately in common plane with the printing face of said molded character, and a backing of friction fabric for limiting the depth of an engraving cut to the depth of the engravable plaque lying immediately behind the plaque in bonded engagement with the plaque and with said integrating body of rubber.

6. The method herein described of making a flexible printing die which consists in simultaneously.v shaping, uniting, and vulcanizing a compound sheet of rubber including a portion formed of rubber of mold'able quality bearing a printing character molded in relief upon it and a portion formed of rubber fnon-moldabie but engravable quality with plane surface, and engraving a printing character in' relief upon the portion of engravable quality.

.v 7..JThe herein described of making a exible printing die which consists in. simultaneously shaping. uniting and vulcanizing a compound sheet of rubber including a portion a molded article, and carrying in vulcanized union with itself an inlay of engravable rubber, such inlay bearing in relief a printing character having the characteristics of an engraved article.

' 'I .EE M. HARLEY.

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