US1998983A - Cut stencil - Google Patents

Description

April 23, 1935. DUGDALE 1,998,983

CUT STENCIL Filed Jan. 21, 1953 2 Sheets-Sheet 1 /4 Jkverztar; W fit'cizardflflzl dale,

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April ,23, 1935. r M. DUGDALE, I 1,998,983

CUT STENCIL v Filed Jan. 21, 1 933 2 Sheets-Sheet 2 'fiOHN DOE s-| 0 HIGH ST5 BOSTON MAss 47 t Inverzzm;

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'a hollow base frame Patented Apr. 23, 1935 warren s'r rss ears-sir orr cr.

Farrington Manufacturing Company, Boston,

Mass, a corporation of Massachusetts. Application'January 21, 1933, Serial No. 652,833

16 Claims.

Heretofore it has been customary to cut stencils on typewriters or other machines having the type in reversed order so that the impression grooves are formed on the front of the stencil material (the side'opposite the side to be presented tothe paper to be printed with the stencil); and the typehas been sharply rounded so that the cuts in v the stencils frequently extend all the way through the stencil material and almost always have holes torn in the bottoms of the grooves even where the material is not cut all the way through. Moreover the grooves formed by successive characters vary in depth and width, due to variations in the height of the cutting characters and/ or to variations in the pressure with which the characters are forced into the stencil material, so that the cut stencils produce uneven printing.

Objects of the present invention are to provide a mode of cutting stencils which produces uniform cutting, with substantially no tendency to out the stencil all the: way through or to tear holes in the bottoms of the cut grooves, which facilitates the cutting operation, and which substantially eliminates spoilage due to improper cutting. Other objects are to produce a cut stencil which affords clear and regular printing, which has long life, and which is generally superior to stencils cut by prior methods and apparatus.

For the purpose of illustrating the genus of.

the invention a preferred embodiment is shown in the accompanying drawings in which,

Fig. l is a side elevation of a stencil cutting machine;

Fig. 2 is a top plan view of the machine;

Fig. 3 is an end elevation of the machine;

Figs. 4 and 5 are transverse and longitudinal sections of the holder or carriagefor the stencil and cutter, with the stencil and cutter in opera tive position thereon;

Fig. 6 is a plan view of a preferred form of stencil cutter;

Fig. '7 is a side view of a modified stencil roller with parts broken away;

Fig. 8 is a section on line 8-8 of Fig. 7;

Fig. 9 is an enlarged cross-section through an embossed character of the preferred cutter shown in Fig. 6; and

Fig. 10 is an enlarged cross section of a cut stencil sheet showing the approx1mate shape of the impression formed according to this invention.

The particular embodiment of the invention chosen for the purpose of illustration comprises i which isrectangular in cross-section as shown in Fig. 2, the side walls being flared from top to bottom and the bottom being covered by a plate secured by screws threaded into lugs integrally connected to the base at the four corners (not shown). The top wall 3 of the base is recessed as shown at 4 in Fig. 3 to provide a guideway extending the full length of the case for a holder or carriage 5 adapted to; carry the stencil cutter on its upper face. A second recess 6 is provided within the recess 4 so that the carriage 5 rests only on narrow guiding surfaces Z along each side of the recess d. Retainer plates it are mounted on top of the frame 3 by means of screws 9 so as to overhang the sides of the carriage, preferably with some clearance between the under sides of the plates 8 and the underlying surfaces it of the carriage 5.

The illustrated machine is preferably used with a stencil cutter such as shown in plan and in cross-section in Figs. 4 and 5. This cutter comprises a thin sheet metal plate having a raised central portion 5! and a marginal portion [2 in terconnected by a shoulder E3 which defines a rectangular recess on the back side of the plate. on the long sides of the plate the marginal portion i2 is made under and is folded under to hold a card 92 in the back recess as shown in Fig. 4. The central portion i i is embossed from the back to form raised characters M which serve to out the stencil.

As shown in-Figs. 2, 4 and 5 the upper side of the carriage 5 has a rectangular raised portion l5 shaped to fit into the recess in the back or" the cutting plate and surrounding this raised portion is a groove 55 the width of which is approximately equal to that of the flange 52 of the plate. Thus when the plate islaid over the raised portion 55 it is held in position by interengagement between the shoulder E3 of the plate and the outside shoulders of the raised portion it and/or by interengagementbetween the edges of the flange 52 and the shoulders defining the outer walls of the groove it. The latter shoulders are preferably discontinued in the middle of the ends and in these gaps recesses H are provided to facilitate the removal of the cutting plate from the carriage;

The stencil intended to be used with this particular machine is of the ordinary type having a rectangular "frame it carrying a sheet of stem, cil material 19. To hold the stencil in position on the carriage over the cutting plate the carriage is provided with shoulders 29 which extend along each side of the carriage and partway across the ends as shown in Fig. 2. The surfaces 2! in Fig. 6

which support the stencil frame immediately inside the shoulders 2d are preferably disposed at such elevation that when the stencil is laid in position, as shown in Figs. i and 5, the stencil sheet is is at substantially the elevation of the upper ends of the characters M. A convenient way of providing the shoulders for positioning the cutting plate and the stencil consists in mounting strips on the top of the carriage by means of screws as shown in Fig. 2.

The carriage is reciprocated back and forth by means of a handle 22, an arm 23, a shaft 24, a pinion 25 fast on the shaft 25 and a rack 2t fast to the under side of the carriage 5 and projecting through a slot in the top of the frame 3. The shaft 2 1 is journaled in brackets 21 each of which is mounted on the under side of the top of the frame 3 by means of two machine screws 28 and two compression springs 23 which extend between the heads of the screws and the lugs 30 of the brackets, the lugs being free to slide on the screws and being yieldingly held against the under side of the top of the frame 3 by the springs 2! Immediately above the brackets 2'! are two brackets 3! having lateral lugs 32 which receive the ends of the screws 28 to hold the brackets against the upper surface of the frame on each side of the carriage. Journaled in the brackets 35 is a shaft 32 geared to the shaft 24 by means of four gears 33, 3t, 35 and 3B. Immediately above the reciprocatory path of the cutting plate a segmental roller 33' is fastened to the shaft 32 in such position as to roll the stencil against the cutting plate as the carriage is reciprocated from one end of the machine to the other. Immediately below the roller 37 a roller 38 is mounted on the shaft 24 to bear on the under side of the carriage 5, through a slot 39 in the top of the frame, the diameter of the rack gear 25 and the roller 258 being so correlated that the peripheral velocity of the roller 38 is substantially equal to the linear velocity of the carriage 5, thereby substantially eliminating friction between the roller and carriage.

The diameter of the roller 38 may be such that when the brackets 2? are seated against the under side of the frame 3 by the springs 29, as shown in Fig. 3, the roller lifts the carriage (or that end of the carriage which is over the roller) off the carriage supporting surfaces l, the aforesaid clearance between the under sides of the plates 8 and the underlying surfaces permitting this lifting, in which case the spacing between the two rollers 3i and 38 is preferably such that when the carriage is reciprocated between the rollers with a cutting plate and stencil on the carriage the upper roller 37, in pressing the stencil against the cutter, presses the carriage and roller 38 downwardly against the action of springs 29, thereby causing the stencil to be cut with a yielding pressure. It will of course be understood that the vertical clearance between the carriage and its guideway is great enough to permit this vertical movement of the carriage and also preferably great enough to prevent the carriage seating solidly against the lower guide surface 'I when the roller 38 is forced downwardly against the action of the springs 29 in cutting a stencil.

However the diameter of the lower roller 38 is preferably such that the carriage 5 is lifted little if any from the supporting surfaces 1, in which case the passage of the carriage, plate and stencil between the two rollers lifts the upper roller 3'! (together with its shaft and the brackets 3 l) upwardly from the frame, in addition to or instead of forcing the lower roller downwardly. In either case the springs 29 produce a yielding pressure between the cutting plate and the upper roller with the stencil therebetween. If the roller 33 is not large enough substantially to lift the carriage from the guideway, the clearance between the overhanging guide strips 8 and the underlying surfaces l0 of the carriage need not be substantial.

While the ratio of the gears which drive the carriage and upper roller respectively may be such that the peripheral velocity of the roller is equal to the linear velocity of the carriage, the gear ratios are preferably such that one of these two parts moves faster than the other to produce a slight rubbing action between the stencil and the face of the roller 31. For use with the usual stencil material, a velocity ratio between the roller and carriage of approximately nine to eight is recommended.

The face of the upper roller 37 is formed by hard material such as steel or a brass alloy, preferably somewhat harder than the metal of the stencil cutting plate. In the embodiment shown in Figs. 1, 2 and 3 the roller is formed from a solid block of such material. In the modification shown in Figs. 7 and 8 the periphery of the roller is formed of segments 43 mounted on a hub 44 by end plates 15 and side plates 4'! with a layer as of rubber or the like between the segments and the hub so that the segments may be.

forced toward the axis of the roller either individually or collectively. While the roller of Figs. 7 and 8 may be used with springs such as 29 (Figs. 1 and 3), it affords good results without such springs, the layer 46 producing a yielding pressure between the stencil cutter and the hard periphery of the roller.

The stencil cutting characters embossed on the cutting plate are preferably formed with sloping sides and a flat top as shown in Fig. 9. I The width of the flat tops depends upon the characteristics of the stencils to be cut but for most stencils best results are obtained with a width of the order of a few thousandths of an inch (e. g. give to ten thousandths). The flat tops are preferably formed by rolling the embossed plate under heavy pressure, with a solid abutment bearing against the bottom of the recess in the back of the plate; and this rolling process not only flattens the tops of the characters but leaves the flat tops in precisely the same plane.

A stencil cut as herein described is characterized by uniformity of the depth of the grooves formed in the stencil material by the cutter and also in that the bottoms of the grooves are torn very little if, any. In its preferred form the cut stencil has grooves which are thin and flat on the bottom, sloping on the sides and bordered by ridges, substantially as shown in cross-section in Fig. 10. The superiority of the resulting stencil is chiefly attributable to the following factors: the use of a hard surface roller with yielding pressure; the characters having fiat tops disposed accurately in line; the rubbing pressure of the roller; the formation of the grooves in the back of the stencil (the side to be presented to the sheet to be printed with the stencil) with nonreversed characters instead of forming the grooves in the front of the stencil with reversed characters. 7

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

IclaimL a r I l. A stencil cutting machine comprising a. carriage movable along a predetermined path, means for carrying a carriage, and a roller journaled on the same side of the carriage in bearings which are fixed longitudinally of saidpath, the periphery of the roller extending into juxtaposition to the stencil cutter progressively to press a stencil against the cutteras the carriage is moved past the roller with the stencil between the cutter and roller. 2. A stencil cutting machine comprising a carriage movable along a rectilinear path, means for carrying a stencil cutter on one side of the carriage, a roller journalled on the same side of the carriage; in bearings which are fixed longitudinally of said path,'the periphery of the roller extending into juxtaposition to the stencil against the cutter as the carriage is moved past the roller with the stencil between the cutter and roller, and

means kinematically interconnecting the carriage and roller positively to cause them to move in unison.

3. A stencil cutting machine comprising a carriage, a rack for reciprocating the carriage along a rectilinear path, means for carrying a stencil cutter on one side of the carriage, a roller journalled on the same side or" the carriage in bear ings which are fixed longitudinally of said path, the periphery of the roller extending into juxtaposition to the stencil cutter progressively to press a stencil against the cutter as the carriage is reciprocated with the stencil between the cutter and roller, and gearing kinematically interconnecting the roller with said rack positively to cause the carriage and roller to move in unison.

4. A stencil cutting machine comprising a carriage movable along a predetermined path, means for carrying a stencil cutter on one side of the carriage, a roller journalled on the same side or the carriage in bearings which are fixed longitudinally of said path, the periphery of the roller extending into juxtaposition to the stencil cutter progressively to press a stencil against the cutter as the carriage is moved past the roller with the stencil between the cutter and roller, and means kinematically interconnecting the carriage and roller positively to cause them to move in unison but at slightly different rates, thereby producing a rubbing action between the roller and stencil.

5. A stencil cutting machine comprising a holder for holding stencil cutting means on one side, a roller on the same side of the holder for progressively rolling a stencil against the cutting means, and a parallel roller bearing against the opposite side of said holder to counteract the thrust of the first roller.

6. A stencil cutting machine comprising a holder for holding stencil cutting means on one side, a roller on the same side of the holder for progressively rolling a stencil against the cutting means, a parallel roller bearing against the opposite side of said holder to counteract the thrust of the first roller, and means for yieldingly urging one of the rollers toward the holder.

'7. A stencil cutting machine comprising a holder for holding stencil cutting means on one side, a roller on the same side of the holder for progressively rolling a stencil against the cutting means, a parallel roller bearing against the opposite sides of said holder to counteract the thrust of the first roller, means for yieldingly urging one of the rollers toward the holder, and a stop for limiting the extent to which the latter roller may be yieldingly urged toward the holder.

stencil cutter on one side of the 8. A stencil cuttingmachine comprising a carriage having means for carrying a stencil cutter on one side, means for reciprocating the carriage back and forth along a rectilinear path, a stationary roller on said side of the carriage for progressively pressing a stencil against the cutter as the carriage is reciprocated along said path and a parallel roller bearing against the opposite side of said carriage to counteract the thrust of the first carriage.

9. A machine for cutting stencils comprising a carriage having means for carrying a-stencil cutter on one side, a rack for reciprocating the carriage back and forth along a rectilinear path, a stationary roller on said side of the carriage for progressively pressing a stencil against the cutter as the carriage is rcciprocated along said path, a parallel roller bearing against the opposite side of said carriage to'counteract the thrust of the first carriage, and gearinginterconnecting said rollers with said rack; a v,

10. A stencil cutting machine comprising a carriage having means for carrying a stencil cutter on one side, means for reciprocating the carriage back. and forth along a rectilinear path, a stationary roller on said side of the carriage for progressively pressing a stencil against the cutter as the carriage is reciprocated along said path, a stationary guiding surface and a roller each bearing against the other side of the carriage, and spring means yieldingly urging the latter roller against the carriage to press the latter away from the guiding surface toward the first roller.

ll. A machine for cutting framed stencils with a sheet metal plate having raised characters on one side comprising a table having means laterally engageable with the plate both longitudinally and transversely thereof and means laterally engageable with, the stencil both longitudinally and transversely thereof to hold the plate and stencil in predetermined relative position when laid on the table in superposed relationship, said means being fixed relatively to each other and located at difierent levels on the table, a roller iournalled above the table transversely thereof to press the stencil against said characters, and means for producing relative reciprocatory motion between the roller and table longitudinally of the table progressively to roll over the stencil and press it against the characters.

12. A stencil cutting machine for cutting framed stencils with a sheet metal plate having raised characters on one side comprising a table having inner shoulders laterally engageable with the plate to hold the latter in position transversely and longitudinally of the table when laid thereon and also having outer shoulders laterally engageable with said frame to hold the stencil in position transversely and longitudinally of the table when laid over the plate, the outer shoulders being fixed at a higher level relatively to the inner shoulders, a roller journalled above the table transversely thereof to press the stencil against said characters, and means for producing relative reciprocatory motion between the roller and table longitudinally of the table progressively to roll over the stencil and press it against the characters.

13. A machine for cutting framed stencils with a sheet metal one side comprising a table having shoulders laterally engageable with the plate and stencil frame respectively to hold the plate and stencil plate having raised characters on 1 ally engageable with the plate both longitudinally and transversely thereof and means laterally engageable with the stencil both longitudinally and transversely thereof to hold the plate and stencil in predetermined relative position when laid on the table in superposed relationship, said means being fixed relatively to each other and located at different levels on the table, a roller journalled above the table transversely thereof to press the stencil against said characters, means for producing relative reciprocatory motion between the roller and table longitudinally of the table progressively to roll over the stencil and press it against the characters and a roller under the table to counteract the thrust of said roller.

15. A machine for cutting framed stencils With a sheet metal plate having raised characters on one side comprising a table having shouliders laterally engageable with the plate and stencil frame respectively to hold the plate and stencil in predetermined relative position when laid on the table in superposed relationship, a roller journalled above the table transversely thereof to press the stencil against said characters, means for producing relative reciprocatory motion between the roller and table longitudinally of the table progressively to roll over the stencil and press it against the characters, a roller under the table to counteract the thrust of said roller and means for yieldingly urging one of the'rollers toward the table to produce a yielding pressure on the stencil while being cut.

16. The method of cutting a stencil comprising pressing the stencil against the cutter with a rolling surface and producing a predetermined degree of slippage between the rolling surface and stencil during the rolling process.

RICHARD M. DUGDALE.

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