US1575508A - Stenciling machine - Google Patents

Description

March 2 1926. 1,575,508

C. G. ROSENHAUER STENCILING MACHINE Filed Dec; 5, 1925 f lnvenvor: i4 /fi/A%W Af'farn Patented Mar. 2, 1926.

UNITED srarss PATENT OFFICE.

CHARLES G. ROSENHAUER, OF BROOKLYN, NEWV YORK, ASSIGNOR To UNDERWOOD TYIPEWRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

STENCILING MACHINE.

Application filed December 3, 1925. Serial No. 72,888.

To'aZZ whom it may concern: 7

Be it known that I, CHARLES G. ROSEN- HAUER, a citizen of the United States, residing in Brooklyn Borough, in the county of Kings, city and State of New York, have invented certain new and useful Improvements in Stenciling Machines,of which the following is a specification.

This invention relates to the for-aminous metal hollow impression drums or cylinders of stencil or duplicating machines, in which it is the practice to wrap an ink pad around the cylinder, and to feed ink to the pad" through the perforations in said cylinder.

The wax stencil-sheet lies upon the ink pad. The work-sheet, which is to be stenciled upon, is pressedagainst the stencilsheet by a roller mounted in the machine.

It sometimes happens that cards are run through the stenciling machines, with the result that the metal stencil cylinder is indented; that is, the card distorts or indents the stencil cylinder, which consists of'perforated'thin sheet-metal, the area of the indentation corresponding with the contour of the card. Not only cards, but also eyelette'd tags, and other work-sheets having protuberances, are run through the stenci cylinder; and heretofore the indentations produced thereby have remained permanently in the cylinder, which is thus rendered ineflicicnt, since it is important that the cylinder should remain cylindrical; and the indented cylinders have had to be removed and shipped back to the manufacturer for truing up. One of the objects of the present invention is to overcome this difficulty.

An object of the invention is to produce an inexpensive stencil cylinder which shall not become indented by thick work-pieces, and which, at the same time, shall be proof against alkali inks and other lILZS.

To secure these advantages. I employ in making the cylinder a perforated plate or diaphragm, which is a sheet of the alloy of copper, silicon and manganese, in which alloy the copper predominates, and in which the proportion of silicon is greater than the proportion of manganese; the silicon rendering the alloy resistant to acids, andthe n'ianganese rendering the alloy machinable and workable, and the alloy being resistant to alkalies as well as acids. This metal, which is known as Everdur, is disclosed in the patent to Charles B. Jacobs, No. 1,539,- 260,, ofMay 26, 1925.

I use for the stencil a semi-hard, hotrolled, unannealed sheet of said alloy, twenty-five thousandths of an inch in thickness; Its universal hammer test is 2830.

Vhen a stencil cylinder of said-alloy is bent by the card or other thick workpiece,

the distortion does not remain (as always the case heretofore), but the cylinder at once recovers its original shape. Moreover it fits or adapts itself better to the protuberance, so that the entire stencil is copied, Whereas heretofore an area of a priceitag or workpiece immediately surrounding the eyelet or protuberance, or the fiber reinforcement, has failed to receive the stencil impression, owingto a large area of the steel or brass stencil cylinder being sprung away from the impression roller. In other words, the cylinder of this alloy is not subject to such bowing away from the work-piece. piece a quarter of an inch thick can be passed successfully through the machine without injury to the cylinder made of said alloy.

The difficulty with the plate or diaphragm, preparatory to bending it into the form of a cylinder, arises at the operation of forming the necessar ierforations in the late.

Cylinders of steel, or brass, commonly used, were at first made with minute round holes considerably spaced apart; but the holes A worlc )IOVGCl inadecua-te for sue 31 in ink and became clogged, and necessitated frequent changing of the ink pad.

Subsequently the round holes were made ing to duplicate said large round holes in said Everdur alloy, it was found that the metal bulged excessively, this bulging being at the middle portion of the diaphragm, and

excessive promincnces and hollows occurred throughout the diaphragm or sheet of metal. It was found that evenness could not be secured by hammering out the highly uneven places, or by annealing the same, or stretching it, or submitting it to other ordinary processes. It maintaineda flour-barrel shape obdurately. The diliiculty arose from the great compression of the Everdur metal around the edges of the numerous punched holes, the aggregate of such compression or peening being very great, owing to the characteristics of the metal, which is open to the objection of peening to a fatal extent.

To avoid this defect, and thereby render said Everdur metal available for stencil cylinders,for which it would otherwise be unavailable, the Everdur cylinder or drum is made foraminous by means of perfora tions, which are of elongated form; the elongations being preferably in a direction circumferenti ally of the cylinder. These perforations in said Everdur metal are of such size and number, and so spaced, that the ag gregate opening over a given area of the Everdur cylinder may be not decreased as compared with the usual steel or brass cylinder formed with large round holes; but owing to the elongation of the hole above mentioned, the area of the unperforated surface of the cylinder is substantially increased, and the extraordinary difliculty arising from the peening of the Everdur metal is Overcome. The action of the alkali and other inks upon the Everdur cylinder is practically avoided, and a substantially better support is given to the work-sheet, ink mat and stencil-sheet at the copying opera-- tion than was heretofore common, while per-- manent denting or distorting of the cylinder from the use of cards or other thick workpieces is avoided, without, however, diminishing the capacity of the cylinder for supplying ink to the pad. At the same time, the ink is better confined to the mat than in the case of the large round perforations heretofore employed in steel and brass cylinders, and the tendency for the ink to be forced back from the mat into the perforations is overcome. Each of the elongate" perforations in the Everdur metal cylinder has a greater area than any round perforation that has heretofore been found practi cable in steel or brass cylinders, and there-- fore a better supply of ink is secured, while the perforationis still short enough so that an extraordinarily strong and substantial cylinder of the described metal may be pro of being rendered unimportant or unnecessary. Said novel cylinders are not affected by any ink and are easily cleaned and stand up under severe work for long periods, without showing indication of deteriorating.

Other features and advantages will hereinafter appear.

In the accompanying drawings, Figure 1 is a perspective view of a drum of a stenciling machine, in which the stencil cylinder is made accurately of a sheet of said Everdur alloy perforated in the mannerstated; the line of pressure upon the cylinder being shown by means of the usual pressure roll; both the work-piece and the ink mat being shown between said pressure roll and the cylinder.

Figure 2 is a cross-section of the parts seen at Figure 1, making it clear, how undue pressure along the line of the impression roll and ink cylinder is apt to bend the latter, as occurs commonly in practice; the bend not being permanent, as is the case where the cylinder is made of the usual steel or brass. Figure 3 is a sectional diagram to illustrate the passing of a thick work-piece through the machine, and showing diagrammatically the bending of said Everdur alloy stencil cylinder by the thick work-piece, which bending is only temporary.

Figure 4 is a diagram of the plate or diaph agm made of said alloy, which-is perforated and rolled up to make the cylinder seen at the-other figures. The stencil drum 10 is in the form of plate 11 of the described alloy, perforated as described and rolled up to make the cylinder. The field of perforations is enclosed by a frame consisting of wide unperforated borders 12 forming part of the originalplate. The area of each circularholein a steel or brass cylinder, according tocurrent practice, is .00515 of a square inch; and for each hole there remains an area of .01O4E75 of a square inch of solid or unperforated metal. That is, in a given field of the usual steel or brass cylinder, the surface area of the solid remaining metal is about twice as great as the aggregate area of the perform. tions in current practice.

In carrying out the present invention, the perforations in the sheet of the described al loy are made underwidth and overlength; in other words, the perforations are elongated and the width is lessened in comparison with the diameter of a circular hole of the same capacity. The underwidth feature of the hole conduces to proper support of the ink mat during the stenciling, and this feature is secured without danger of the'hole becoming clogged with ink, by reason of the expedient of making the hole overlength; that is, the length of the hole is greater than would be the diameter of a circular hole of the same capacity: while the underwidth and overlength of the perforations render it possible to employ the described intractable alloy, since thereby is avoided the initial dis-- tortion of the cylinder into barrel or undulating form. a

The width of is about 3/64 of an inch.- The over-all length of the perforation is about 3/16 of an inch, this length or form of hole per-- mitting the use of a hole-punching die of substantial character, and the effects of peening the Everdur alloy are practically avoided. The perforation is preferably straight-sided, with semi-circular end portions. The perforation extends in a direction around the cylinder. Each circumferential row of elongated. perforations is spaced .125 of an inch (measuring from center to center) from the next row, or 8 rows to the inch. The rows are evenly spaced, and (considered circumferentially of the cylinder) the distance from the central point of each elongated perforation to the center of the next is one-fourth of an inch. In each circumferential row the elongated perforations are staggered with reference to those in the next row, each perforation being preferably opposite the space between adjacent perforations in the next row; the perfo 'ations in alternate rows being preferably in line with one another.

The area of each elongated hole is about .00831 of a square inch; and for each hole there remains about .02295 of'a square inch of solid alloy as described. Thus, ina given field of the cylinder, the surface area of the solid remaining Everdur alloy is nearly three times as great as the aggregate area of the perforations, thus producing adequate support for the ink-pad and copy-sheets and securing adequate flow of ink; The advantages are gained by the use of a perforation whose area is about greater than the area of the circular perforation of ordinary brass or steel stencil-cylinders.

It is one of the advantages flowing from the invention that in punching the perforations in the sheet of the described alloy, there is absence of resultant springing, bending, warping or bulging of the Everdur cylinder-wall, which is a common drawback in punching the round holes in current practice, even in steel and brass cylinders. In practice, two adjacent longitudinal rows of perforations are punched at one operation; then the Everdur cylinder is rotated to the next punching position and the punching operation is repeated, and so on until the perforating of the cylinder is complete. At the conclusion of the punching operation, the plate of the described alloy is found to be substantially flat, or without objection able bulging.

At Figure 3 there is shown diagrammatically the described stencil cylinder 10, a

each oblong perforation 18 pressure roll 14, and an ink-mat 15; and two plies of card '16, such as fiber. are pressed so firmly by the roll 14 as to form a temporary depression at 17. in the cylinder. The bottom of the depression in the cylinder remains approximately straight, rather than becoming substantially bowed or curved-so that stenciling is successfully effected upon the work-piece. The'described cylinder recovers its true cylindrical form aft-er the passage of the cards.

J-Variations may be resorted to within the scope of the invention, and portions. of the improvements may be used without others.

Having thus described my invention, I claim:

1. A foraminous sheet of the described copper-silicon-manganese alloy, rolled up and forming an unbulged cylinder upon which is placed an ink mat and a stencilsheet, the perforations in said sheet being of substantially elongated form, avoiding the described peening tendency of said alloy, said perforations extending circumferentially of the cylinder.

2. A foraniinous sheet of thedescribed copper-silicon-manganese alloy, rolled up and forming an unbulged stenciling cylinder upon which is placed an ink mat and a stencil-sheet, said sheet provided throughout with underwidth and overlength perforations regularlyspaced apart to such an extent that the aggregate unperforated or solid area of the foraminous field is more than twice as great as the aggregate area f the perforations; said perforations in the direction of their length extending around the cylinder. v

3. A foraminous sheet of the described copper-si.liconma'nganese alloy, rolled up and forming an unbulged stenciling cylinder provided throughout its printing field with elongated perforations, the direction of the elongations being around the cylinder, the

Width of each perforation being about 3/64 of an inch, and its length being about 3/16 of an inch, and having parallel side edges and rounded end portions.

4. A foraminous sheet of the described copper-silicon-1nanganese alloy, rolled up and forming an unbulged stenciling cylinder provided throughout its printing field with elongated perforations, the direction of the elongations being around the cylinder, the width of each perforation being about 3/642 of an inch, and its length being about 3/16 of an inch, and having parallel side edges and rounded end portions, the perforations being in rows which extend around the cylinder, and the distance from one row to the next being about, 1/8 of an inch, measuring from the centers of the perforations. I

5. A forannnous sheet of the describec copper-silicon-manganese alloy, rolled up and formlng an unbulged stencihng cylinder provided throughout its printing field with elongated perforations, the direction of the elongations being around the cylinder, the Width of each perforation being about 3/64 of an inch, and its length being about 3/16 of an inch, and having parallel side edges and rounded end portions, the perforations being in rows which extend around the cylinder, and the distance from one row tothe next being about 1/8 of an inch, measuring from the centers of the perforations, and the distance from the center of one perforation to the next, in the direction of the length of the perforations, being about 1/4 of an inch.

6. A foraminoussheet of the described copper-silicon-manganeze alloy, rolled up and forming an unbulged stenciling cylinder provided throughout its printing field with evenly-spaced perforations elongated around the cylinder, there being about thirty-two perforations to the square inch, and (ach perforation having a Width of about 3/64 of an inchand alength of about 3/16 of an inch.

CHARLES G/ROSENHAUER.

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