US2475336A - Ribbon feeding and inking mechanism for typewriting machines - Google Patents

Description

y 1949- J. a... PETZ RIBBON FEEDING AND INKING MECHANISM FOR TYPEWRITING MACHINES Filed Feb. 15, 1945 ATTORNEY Patented July 5, 1949 UNITED! STATES PATENT Application- February 15, 194'5 ,T Serial Ni). i8T0 5 2 1 Claim. (Cl. 19-7 -168) This invention relates to typewriting'macliines.

The primary object of the present invention is to provide a novel inking mechanism for typewriters and other office machines;

An object is to provide an inking mechanism which avoids the use of fabric inking ribbons which must be impregnated with ink prior to insertion in the machine.

An object is to provide aninking mechanism in which it is possible to "change the ribbon without soiling the fingers.

An object is to provide an inking mechanism which is considerably simpler andmore reliable than ordinary ribbon feed mechanisms by reason of the elimination of the ribbon reversing feature.

An object is to provide an inking mechanism which employs an ink transfer" member which may consist of a ribbon which is kept uniformly inked while the machine isin' use.

An object is to provide an inking mechanism which may utilize ordinary printers ink.

Other objects of the invention will-be pointed out in the following description and claim and illustrated in the accompanying drawing, which discloses, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

The single figure is a perspective view of a portion of a typewriting. machine to which the inking mechanism forming v the subject of the present invention is shown applied.

In the drawing, the numeral I designates the base of a conventional typewriter well known in the art as the Electromatic. It will be understood, however, that the inking mechanism may be applied to other machines just as readily. as for th one selected for purposes of illustration of the invention. Type bars like the type. bar 2 are mounted in the usualsegment 3 to which is attached the type guide 4. slidably mounted on the type guide is the usual ribbon vibrator 5 which is located in front of the card guide 6.. The card guide is located in front of the platen l which is mounted in the carriage (not shown) in the usual way. The type bars are controlled by the keys 8 and are operated by apower roller- 9 which is selectively coupled to the type barsby means of the keys 8 in a well known way.

The ribbon mechanism includes an ink pot 9 which is secured to the left-hand side ofthebase l and containsan ink pick-up roller It which is rotatable in suitable hearings in the ink pot 9. The roller I0 dips-well below the level-of the ink in the ink pot 9" so as to be always capable of picking up ink. The shaft H of the roller i0 2 extends outside of thednk *pdt *9 andhas' secured to '11: a'be'vel ear 2 'whi'clfnieshes" with a "bevel ear [3' secured-to a; vertical shaft f4. This shaft is journal'ed ina pair "of brackets 'l 5" secured to the"sid'e"ofth'e base landat its lower end has secured toita) pinion "IG "which meshes" with 'a worm" H fixedto a shaft 1'8 journaled inthe'base I by any suitable rriearisi shaftl'8 extends interiorly ofthe-base! and'ha's" secured to it a frictionroller'l 9 whichengages the-surface of the p'owenrolle'r 9; Since the-power roller 9 rotates continually while tire-machine use," itis' evident that the"ihk"pick'"lllp rdn'eflfl will like WiSe: be continuanyturningand-have its urface continuallycovered with" "'filni'ofinki The gear ing is such that theriill'ef-"lfirdtats relatively slowly compared 'to th pcwer' roller 3 in order to avoid throwin'g'ofi the ink by centrifugal force. Cooperating withtne"roller!!!- is a doctor blade zn=wmen is arranged to" spread the"'ink "evenly onthe roller Ill." Also coa'ctingwr'iththe' roller ID is an ink'spreading roller 2 I which" is jouriia'led in the ink p'ot' 9*and"dri'veriby"the roller In through" gears 22 secured-"to the-shafts of the rollers I'D and" Zl, respectively? Also"io'urnaled in the ink pot Bis anink transfer roller 23' and secured to its shaft'is agarfZfl which meshes with'the' geafZ TSECIIIed to tfle'roll'ehfl. The gears 22 and are located outside the ink pot' 9. Pivoted 'on a bracket 25, which may be formed as a" part of the ink pot Sfor separately attached thereto, is a lever 26" havingpivote'd' near" its front end a'pressureroller"'2l dispc'ise'dabove the roller 23. Theroller'z'f is" actuated" toward the roller 23 by a toggle'springln"iriterpbsed between a p'i'ncarried bytheb'a'se" l and'afpiii carried by the rear arm'ofleverfzfi'f Normallyi'tog'gle spring 28 urges the lever ztm a clockwisldi'rection but; when it is desired to change theribboh, the lever 26 may be raised by han'djby means of afing'er piece 26a; far 'enougntof permit "the toggle spring 28 "to'swing' the lever 2'6"'inj'the other"dire'ction and hold it inrel'eas'ed posarbnby reason oflever' 26 engaging the rear side of the ink pot 9L secured to [3116 base:- I ar th riii ribbon 'glllide members 29 disposed"ofi opposite i sides "of the ribbon vibrator 5" 'justwin' front of 'the platen and a'- -little:-below the level of-the usual loops in the ribbon vibrator throughwhich -p'ass'es the inking ribbon. Secured to the-front-plate3ii=isa second pair of front ribbon guides 3l anda guide finger 32-which is located at -approxim'ately the center oftth e plate 30 I v p The guides 29am. 3] support an ink'tr'ansfer ribbon 33"'which' passes in newer finger "32 and through the usual loops in the ribbon vibrator 5. The ribbon 33 also is twisted horizontally at the left-hand side of the machine between the lefthand guides 29 and 3| and passes between the transfer roller 23 and the pressure roller which serves to keep that face of the ribbon which confronts the platen 'iat the ribbon guide ii firmly against the surface of the transfer roller 23. Since the direction of rotation of the roller iii must be clockwise to render the doctor blade 29 effective, it is evident that the roller 23 likewise will be rotated clockwise thereby imparting continuous motion to the ribbon 33 in a counterclockwise direction in the drawing considering the entire loop of the ribbon as a Whole. Thus, While the ribbon is in use, the face thereof confronting the platen at the printing point is continuously kept supplied with ink whioh it is preferred to be printers ink of the proper drying characteristics.

It has been found from experience that best results are obtained when the ribbon I33 is made of the well known synthetic plastic known as vinyl chloride, a material having many of the characteristics of rubber. A commercial form of this material is known under the trade name Koroseal and is a polymer of vinyl chloride. Such a ribbon is highly flexible and resistant to the destructive action of the oils which are commonly found in printers inks which tend to rot rubber. However, equally good results could be obtained with a ribbon made of synthetic rubber of the proper type, by reason of the fact that it is Well known that most synthetic rubbers are highly resistant to the rotting action of the oils found in printers inks.

One of the advantages of using vinyl chloride is that, while it is not as elastic as rubber, it tends to quickly resume its original length when stretched as it might be in the process of insertin such a ribbon in the machine. Also, this plastic is very cheap and the ribbon may be discarded at frequent intervals when too much ink has dried on the surface of the ribbon. It has been found, however, that a ribbon composed of vinyl chloride may be used for a considerable length of time before it must be discarded.

Since the ribbon 33 does not have to be impregnated yvith ink prior to its installation in the typewriter, it may be inserted without soiling the hands. In removing the ribbon even though it is soiled with ink, it may be grasped with a piece of scrap paper to protect the fingers and torn from the machine and discarded without soiling the operators fingers. In the event the ribbon breaks during the use of the machine, the loss is practically negligible since the ribbons may be sold for a trifling cost.

It will thus be seen there is a desired advantage in the ribbon mechanism described herein arising from the fact that the ink transfer element which cooperates with the type bars is cheap and may be easily installed without any mess.

When installing the ribbon it is desirable to swing the lever 26 upwardly and rearwardly of the machine and then insert the ribbon in the loops of the ribbon guide 5 in the usual way before looping the ribbon around the front guides 3i and in front of the finger 32. The stretch of ribbon between the right-hand guides 29 and 3| may then be twisted with the finger and the lever 26 restored to its original position. The finger 32 prevents the ribbon from swinging into the path of the foremost type bars in the type basket.

The ribbon inking mechanism described herein is especially advantageous in machines designed for the preparation of the master sheets used in making photo-offset printing plates by reason of the fact that the inked impressions produced thereby are much clearer and more solid than those produced with conventional fabric ribbons impregnated with ink. The reason for this is that when the types strike through ordinary fabric ribbons, the outline of the characters is not sharp and the bodies of the characters are not uniform in tone because of the fact that the weave of the fabric ribbon is impressed upon the paper and the ink transfer is greatest at the diameter of the threads arising from the greater compression of the fibres of the high spots and hence stronger expressions of ink from the fabrics at these points by the impact of the type bar, When a ribbon such as the one described herein is used its surface is smooth and covered with a uniform film of ink which likewise is uniformly transferred to the paper by the type with a clear, sharp impression as in ordinary printing from set type.

In preparing printing plates from photo-offset master sheets, it is necessary that the characters be clear and sharp and that they be uniformly black as the plates are prepared by photography and is desired to have maximum contrast in the film. Particularly is this necessary when the master sheet is to be enlarged so that the characters printed by the plate will be larger than the originals. In the past the desired characteristics of the master sheet have been obtained by using carbon paper ribbons instead of inked ribbons but such carbon paper ribbons are quite expensive since they may be used only once and then discarded. When comparing carbon paper ribbons with the unimpregnated ribbons used in the mechanism disclosed herein, there is a desired advantage in the latter from the cost standpoint since the ink may be obtained on a bulk basis and the ribbons themselves will cost only a trifling sum.

While there have been shown and described and pointed out the fundamental novel features of the invention, as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claim.

What is claimed is:

In a machine of the class described, in combination with the typing devices and power actuating means for the typing devices, an endless ink transfer ribbon for inking the faces of the type, means to guide said ribbon past the printing point of said devices, and ribbon feeding and ink transfer means including an ink fountain and an ink transfer roller actuated by said power actuating means for continually feeding said ribbon and at the same time transferring a film of ink of the face of the ribbon confronting the work sheet receiving the impressions of the typing devices.

JOHN L. PETZ.

(References on following page) 5 REFERENCES CITED Number The following referen ces are of record in the 11112 01 ch18 patent. 2:246:195 UNITED STATES PATENTS 5 2,387,330

Number Name Date 1,133,597 Wilson Mar. 30, 1915 N b 1,405,915 Evans Feb. 14, 1922 2 1,455,110 Crawley May 15, 1923 3 1,923,505 Richardson Aug. 22, 1933 10

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