US2114850A - Duplicating machine - Google Patents

Description

April 19, 1938. o. H. MANZ DUPLICATING MACHINE Filed Aug. 8, 1935 3 Sheets-$heet l INVENTQR 0210 HdManz svallui I/Itrlill/dlll/II! M4. ATTORNEY 2 N A M H o DUPLICATING MACHINE Filed Aug. 8, 1935 3 Sheets-Sheet 2 R O T N E V m h 0H0 H Manz l aim/id. [5L0 2& ATTORNEY A ril 19, 19. o. H. MANZ DUPLICATING MACHINE Filed Aug. 8, 1935 3 Sheets-Sheet 3 lllll- INVENTOR 0H0 H Mans 7464; ATTORNEY Patented Apr. 19, 1938 NIT'ED P ATEZ-NT "O FFI "'Claims.

This invention relates to 1 improvements irin duplicating machines-particularly theitypetcommonly known as mimeograph machines. Asource of difiiculty with these machines is the::collection of lint, or particles of paper, on. thesheetsrsbeing printed, that is carried into' contact vwith the stencil and which soon ends-its usefulness. One of the objects of this invention is means whereby the lint is disposed ofibeforerrreachingithe stencil.

Another. object of my. inventionresides in the provision of means for=separatingitheeedges-of the paper stock and blowing-thewsheets apart whereby only'one at a time will; pass-through the machine. My invention --.also comprises i novel means for stripping then-paper -fromithe stencil after it has been printed andguidi-ng: it. into; the receiving rack, thuspreventingthe sheetifrom passing around with the stencil andwcloggi-ngit-he apparatus. In addition the invention provides means for rapidly drying the on the;.pa-per:to prevent smudging of the pr-intedrmatterby successively delivered sheets.

Other features and-advantages of thecinvem tion will be hereinafter described andclaimed.

In the accompanying drawings:

Figure 1 is a view in verticalzsection through a duplicating machine incorporating .my-.invention, taken on line I-|.of Figure 2.

Figure 2 is a top view of a'mac-hine-embodying my invention.

Figure 3 is an end elevation with. some-oi the parts removed.

Figure 4 is a view taken on-line-4--4 of Fi ure 1.

For the purpose of illustratingtherprincipleof my invention, I have show-nit embodiedirinia duplicating machine of usual construction. The sheet delivery means of the duplicating machine as shown in the drawings comprisesacylinder for holding thestencil or other printing means and an impression roller 2. The cylinder I is mounted on trunnions 3 in the upper part of the side walls 4 of the frame of the machine.

As the sheets to be printed are fed between the cylinder and impression roller they pass over a feed table 5 supported from the frame of the machine. The sheets may be fed into the machine by the feed rolls 6 in the manner which is usual for machines of this type, and are mounted on a shaft 1 driven by gears in timed relation to the rest of the machine. A roll 8 carried by a yoke pivoted on an axis transverse to the machine acts to hold the sheet of paper down against the feed rolls 6.

. to the stencil it is: forced therethrough making .holes. therein; thus-ending its usefulness and con- 'zThe stack of; sheetcpaperi from which the feed (rolls:(it-successively: remove the uppermost sheet isusupported on a.t'able*0 which is continuously rraised *in the-.iusualzimannerduringoperation of itheamachinexso as to maintain the: top sheet in proper position to be fed into the machine. The

:paper feed carriage: 10 1s mounted on rails H and I2 .-.and is moved-back and forthbythe action of wmembersl l and l2,wvhich'members are pivotally mounted on: arms l3' and I l4 respectively. 10

The-arrangement in part illustrated by members 4-0 to I4.is--.knownwas'the sheet feeding: mecha- .nism-uand-: its purpose -is.to remove .one sheet at .a time from beneath the:paper grippers l5. and rideliver it to .theffee'd rolls-6 and 8. .Thepaper l'b ngrippersi5 move :up and down in properly timed relation to the other parts to release and grip the .frontend of the-stack ofypaper in the=usual manner.

rTheupaperistock iused in these machines is cut;

This-is chine and clean the stencil. .The cleaning operation,-which is performed with a soft brush or spongeesmears the ink. on the stencil andseveral sheets mustbe run. through: the machine before the printingissagain satisfactory. A stencil can .onlyistand somuch cleaning toremove. the lint and I have found that after printing from 5,000

,to 10,000 sheets the stencil must be discarded.

After -a certain amount of. lint becomes attached stitutes another reason for it being prematurely discarded.

One part of my invention comprises a method and apparatus for removing the lint from the sheet before it reaches the stencil. As a result of my improvement I can use the same stencil to print from 150,000 to 200,000 sheets without having to clean it.

To accomplish the above result, means are provided for directing a stream or streams of air onto the paper in a direction that will blow the lint away from the stencil roll. The means comprise a blower or fan enclosed by the housing l1 driven by a motor Hi. The air under pressure is carried through a pipe Hi to nozzles I 9, which nozzles are positioned between the paper stock and the stencil roll. The 'air from the nozzles blows all of the lint or other small particles off of the paper thus obviating any possibility of them being fed into the machine. The nozzles have another function in that they are positioned so that the stream of air strikes one end of the paper stack and causes the sheets to be separated. By this means it is possible to print much thinner paper than heretofore. When very thin paper is used the sheets tend to stick together and the carriage i 9 often pulls back two or more sheets of paper at a time from beneath the paper grippers it; instead of only one with the result that many blank sheets pass through the machine. When the stream of air is used the sheets in the upper part of the paper stack are separated (as shown in Figure 4) and the tendency to stick is overcome. It has been found impractical to use paper thinner than what is known as 16 pound paper (16 pounds to the ream) in mimeograph machines because of the difiiculty in feeding a thinner paper. With the air blower 11 pound paper can be fed through the machine one sheet at a time.

Figure 4 illustrates the action of the air in separating the sheets. The nozzles 9 at each side of the machine first blow the adjacent corners of the paper upward since the sheet will bend easier at the corners than at intermediate points thereof. After the corners are raised the air from the intermediate nozzles raises the center of the sheet. In operation the action is almost instantaneous and the top sheet is separated back to the feed carriage after it is released by the paper grippers l5.

It is customary in machines of this sort to interleave blotters or separators between the sheets after they have been printed. This is necessary to prevent smudging due to contact between successive sheets before the ink is dry. I have found that heating the paper just before it is printed will dry the ink sufiiciently to eliminate smudging, thus obviating the use of blotters and interleaving mechanism. I prefer to heat the stream of air as by passing it over an electric heater coil 20 mounted in the pipe I8 (see Figure 2). The hot air constantly blown on the paper warms it enough to dry the ink after the sheet has been printed.

Means are also provided for positively causing the paper to leave the stencil roll after being printed. The nozzle 2| is connected by a hose 22 to the air input side of the blower. A partial vacuum is thereby created at the end of nozzle 2i which reduces the air pressure beneath the printed sheet as it is delivered from the stencil roll. The air pressure above the sheet being greater than that below, results in the sheet being peeled from the roll and sliding down into the rack 23 which is provided to receive the printed sheets. I have found that if means are not provided to positively remove the paper from the stencil roll it is apt to stick to the stencil, revolve with it and clog up the mechanism. This also often ruins the stencil.

Furthermore, the action of the partial vacuum created at nozzle 2| guides the paper in such a manner that the successive sheets are placed in a neat pile greatly facilitating counting and making into pads.

It may thus be seen that my invention provides means for greatly increasing the life of the stencil, assures delivery of a single sheet at a time, eliminates complicated interleaving mechanism and positively removes printed sheets from the stencil. The apparatus is simple and inexpensive and may be easily applied to any duplieating machines now in use.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

1. In a duplicating machine, in combinaticn, a stencil drum, means for feeding the paper to be printed into contact with the stencil, and means comprising a blast of air for preventing loose particles of matter from being carried by the paper into contact with the stencil.

2. In a duplicating machine, in combination, a stencil drum and paper feeding means, an air nozzle between said drum and a part of said feeding means, said nozzle being constructed and arranged to direct a blast of air on the paper to be printed to clear the paper of loose foreign particles before the paper reaches the stencil drum.

3. In a duplicating machine, a sheet delivery mechanism, a stencil drum, and means adjacent said drum constructed and arranged to create a partial vacuum beneath the sheets to cause the latter to leave the drum.

4. In a duplicating machine, a stencil drum, means for feeding the paper to be printed into contact with the stencil, and means above the paper directing a blast of air thereon for preventing loose particles of matter from being carried by the paper into contact with the stencil.

5. In a duplicating machine, a stencil drum, means for feeding the paper to be printed into contact with the stencil, and means above the paper and between said drum and a part of said feeding means constructed and arranged to direct a blast of air on the paper to be printed to prevent loose particles of matter from being carried by the paper into contact with the stencil.

OTTO H. MANZ.

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