US1937720A - Protected inking fabric - Google Patents

Description

Dec. 5, 1933. E, w. SIBLEY 1,937Q720 PROTECTED INKING FABRIC 7 Filed April 3, 1929 Patented Dec. 5, 1933.

PROTECTED INKING FABRIC Edward W. Sibley, Kenmore, N. Y., assignor to Remington Rand Inc., Buffalo, N. Y.

Application April 3, l929. Serial No. 352,307

10 Claims.

This invention relates to protected inking fabrics, and it has particular reference to an inking fabric such as a typewriter and like inking ribbon in which a protective medium is applied to prevent smudging of the paper or gumming of the type, and wherein the protective medium is so disposed as to provide an ink reservoir of high capacity and a printing portion 'for applying ink to form clean characters during the life of the ribbon, and to a ribbon which may be employed to print characters of uniform weight, density or appearance during substantially its entire life.

While the present invention is applicable to a number of forms of.inked fabrics adapted to create an'impression or to imprint a character when struck or impressed by a hard body, such as type of a typewriting or computing machine, multigraph machine or a date stamp, the principles will be described with particular reference to typewriter ribbons. Typewriter ribbons are customarily made of textile fabric and may be of cotton, silk, linen or the like. These ribbons vary in width, those in most general use being about one-half inch wide and are saturated or impregnated with a non-drying ink con taining essentially a non-drying vegetable oil having an aniline color dissolved therein and admixed with a mineral oil and a pigment.

The initial impressions made on the paper by afresh or new ribbon are usually blurred or smudgy, due to the large readily available volume of ink in the ribbon which also tends to clog and gum the type of the writing machine. Such smudging and gumming are undesirable, but to a large extent'these effects have been accepted as necessary evils in producing a ribbonhaving a reasonable length of life. As the ribbon is used, a stage is reached in its life when 40 the smudging and gumming effects are not so pronounced and the impressions made by the type are fairly clear and sharp. Toward the end of the life of the ribbon the characters are fainter, due to the depletion of the available ink supply contained in the ribbon.

In most modern typewriting machines, ribbon control mechanism is provided for bringing either the upper or lower half of the ribbon into the paths of the types, so that a polychrome ribbon may be employed if desired, or a single color ribbon may be used along two lines in the width of the ribbon to thoroughly exhaust it. Therefore, examination of a worn typewriter ribbon usually will reveal a zone on either side of the center line and within the marginal portions which is well worn from repeated impacts of the type. These zones or lines of impact constitute the portions of the ribbon which are actually struck, there being marginal regions and a central portion which are not struck by the type in most of the present day typewriting machines.

Heretofore in machines such as typewriting machines considerable effort and ingenuity and skill have been expended in developing and putting into commercial production type of uniform shape and dimension and fine and accurate outline. Despite progress made in this regard this standard of perfection has been rendered somewhat non-effective by reason of the characteristics of the ribbons employed. The. ribbons constitute intervening or intermediate factors, susceptible and capable of wide variation initially and perhaps wider variation during use. It must be acknowledged that these effects determine, to a large degree, the ultimate appearance of the impress of the type upon the paper or object being written upon.

The matter of preventing smu g and gumming in a new ribbon has received some attention from prior inventors. It has been variously proposed from time to time to apply coatings of various natures to either or both surfaces of the ribbon, and to coat the type side of the ribbon with an impervious material such as shellac or 5 collodion. Some of these prior art proposals, such, for example, as applying an impervious coating of sodium silicate to the paper side of the ribbon, and applying the ink on top of the impervious coating, contemplate the application of the ink to the paper from a non-fabric surface. The writing is done from the surface of the impervious material.

These, and other proposals, however, have not met with the expected or desired success in practical operation for a number of reasons. In considering the nature of a ribbon of woven textile fabric, it may be pointed out that the porosity and texture of the material determine, to a i great extent, the capacity of the ribbon as an ink reservoir. It may. be here noted that the ribbon, when serving as an ink reservoir, must act in the nature of a sponge, and that the ink capacity is directly measured by the absorptive properties of the fabric. Only that amount of ink can be retained in the ribbon which fills the voids, interstices or pores thereof plus an additional amount retained by adhesion or cohesion of the fabric and ink particles. When a saturated ribbon of this type is first used, an

excessive amount of ink is liberated by the im-- pact or impress of the types, while, during the latter part of the life, much greater pressure is required to extract any ink at all from the ribbon pores. why the type impressions are not uniform, or why the period of uniform impression is limited.

Another factor to be considered is that a coating, such as certain heavy and impervious coatings of the prior art, in some degree destroys in the fabric ribbon one of its most valuable functions; namely, its absorptive power. It has long been customary in the operation of certain types of printing-machines to employ smooth, impervious, and none-absorptive ink. transfer rolls, which carried .a superficial film of ink supplied periodically from a liquid ink reservoir. The use of impervious coatings for typewriter ribbons apparently finds its genesis in the gelatinous rollers of the earlier printing art, but, as noted, in considering typewriter ribbons, these heavy, impervious, or pore filling coatings are not suited for use in typewriter ribbons, or printing devices wherein the ink supply must be integral with the transfer means.

Despite the lack of commercial or practical application of such coatings to the conditions herein considered, it must be bornein mind that by proper-use of such material, some desirable results may be obtained. Gumming o r smudging of the type or paper by a typewriter ribbon may occur even though the ribbon is not highly saturated withink. Ribbons of cotton, silk, or the like, present projecting antenna or fibers which, under the microscope or to the naked eye, maybe observed as small wicks or brushes, likely to take any direction, and so apply ink around the edges of the type impression. So long as this condition obtains, the blurring of the impressed characters is apt to persist.

The problem presented, therefore, with particular reference to typewriter and like ribbons as employed in present day machines, involves a careful reconciliation of. several conflicting factors. It is obvious that the ribbon must be made to suit the machine, that the ribbon must serve as its own ink reservoir, and hence have a high ink capacity, and that, therefore, the use of coatings is contra-indicated. Bearing in mind these material economic and practical considerations, it will be apparent that the possible means of improvement, for obtaining the desired results, is somewhat restricted.

In meeting this problem according to the present invention, it is proposed to construct a typewriter or other inking ribbon of the usual fabric constituting a base or reservoir for ink,-

and having a printing or type-contacting portion formed thereon by treating limited areas of the ribbon surface. The treated areas are adapted to face the paper, or other material to be written on. The treating material or protective coating is a. substance, which, in and of itself, is' not wholly'impervious, and it is so applied as to prevent the textile material of the ribbon from breaking down or raveling, or re leasing fibers or portions of fibers which would tend to smudge the paper or distort the clear, clean outline of the writing. This treatment is further adapted to prevent excessive diffusion of f the ink onto the paper through said coating which constitutes the imprinting surface, but it is not, however,'to be confused with the heavy,

or wholly impervious coatings previously dis- These effects indicate the reasons cussed, since the ink capacity of the ribbon is not impaired. A

The several and collective features, objects, and advantages of the invention may be more fully understood from the following description of certain illustrative embodiments of its principles, reference being had to the accompanying drawing wherein:

Fig. 1 is a fragmentary plan view of a typewriter ribbon having its upper portion only and on one side treated with protective material;

Fig. 2 is a fragmentary plan view of a similar ribbon having spaced coatings on both sides thereof;

Figs. 3 and 4 are respectively transverse crosssectional views of the ribbons shown in Figs. 1 and 2;

Fig. 5 is a fragmentary plan view of a ribbon treated on opposite sides for different widths, and useful especially in bichrome printing; and

Fig. 6 is a transverse cross-sectional view of the ribbon shown in Fig. 5.

The typewriter ribbon shown in Fig. 1 comprises a textile fabric or body portion 10 of the ribbon which may be of cotton, silk, artificial silk, linen or any other fibrous material having a high ink absorptive power and capable of formation into a fabric of suitable strength and flexibility. This ribbon is treated with a protective material or coating over a longitudinally continuous zone, to provide a protected surface 11 which is adapted .to face the paper. The body portion 10 of the ribbon is adapted to be struck on its untreated or uncoated side by the type. It will be noted that a marginal portion 13 of the ribbon is not treated or coated and that the lower portion 14 of the ribbon also receives no coating treatment. The protected surface 11 constitutes that portion of the ribbon which is apt to contact with the paper, and the remaining portions of the ribbon are unimpaired for the purpose of absorbing a maximum quantity of ink.

The material forming the protective layer of film 11 is preferably regenerated cellulose or a cellulose ester. In practice, a solution of viscose, or a solution of cellulose ester in a volatile solvent, is applied tothe indicated portion of the surface of the textile body 10 of the ribbon. In ordinary methods of application, an appreciable penetration of the fabric by the protective material will be obtained, and hence the absorptive capacity of the ribbon will be decreased to a certain extent. In this way of treating, the film 11 is substantially continuous, being broken by only occasional minute pores.

In making a ribbon of this character, the ink is applied after the film has been formed and converted or dried to a stable condition. In using the ribbon, a thin film of ink flows onto the face of the layer 11, being fed by capillary action or surface tension effects from the reservoir residing in the body of the fabric 10. The ink absorptive capacity of the ribbon is not decreased unimpaired to an extent suflicient to affect the use of the ribbon in the ordinary manner, and the fibers which tend to cause smudging of the paper are matted down or covered and so can not exercise their disadvantageous functions.

A ribbon of this type is also indicated particularly when considering bichrome ribbons, such as a red and black ribbon or ribbons wherein it is desired-to write certain portions of the composition in bold type but in the same color as the ill remainder of the writing. Thus, for ordinary writing purposes, the ink will be supplied through or over the layer 11, but when emphasis is desired, the shift key of the machine which controls the zone of the ribbon in use may be operated and the ink may then be supplied from the untreated or uncoated portion 14 of the ribbon to print characters which stand out more distinctly. Certain commercial conditions indicate that in using the red field of a bichrome ribbon, the smudging or irregularity of the impressions is not so apt to occur, and being used only occasionally is not a serious defect, and hence the ribbon illustrated in Figs. 1 and 3 may be considered to be a black and red ribbon wherein the black portion of the ribbon only is protected by the strip 11 on the paper side.

Even better results may be obtained, however, by so forming the layer 11 as to remove it from the category of a coating. In this aspect of the invention, what is contemplated is a highly open textured film, rather discontinuous in character and resulting from so light an application of the treating material that only the projecting fibers from the exterior threads are matted down or fixed. In one way of explaining this feature, it may be stated that the warp and weft threads constitute ridges with pyramidal depressions formed between adjacent pairs of threads. The extreme edges or high spots of these threads only are treated so as to make them perfectly smooth and care is exercised to avoid the flow of protecting material into the depressions or interstices between the threads. With a ribbon of this character, ink may flow through the spaces between the filaments of the protecting material, and it has been discovered that irrespective of the degree of saturation of the ribbon with ink (within certain obvious limits) the weight or density of the characters imprinted is practically uniform. It has been discovered that the ink tends to distribute itself throughout the ribbon and hence upon the occurrence of any local deficiency, ink will flow from a more saturated portion to that region which has just been depleted. In view of this, it is possible to obtain uniform printing during the life of the ribbon, to conserve the ink supply when the ribbon is highly saturated, and to utilize the conserved portion. when the ink concentration becomes materially diminished.

The ribbon shown in Figs. 2 and 4 is provided with two spaced longitudinally continuous treated portions on both sides of the ribbon, as indicated by the reference numerals 15, 16, 17 and 18. The portions 19 and 20 at either edge of the ribbon, and the portion 21 along the center of the ribbon, constitute high capacity and high pressure ink reservoirs from which the ink may flow by capillarity or other molecular force through the protective layers 15 and 16. The protective layers 17 and 18 are on the type side of the ribbon, and serve to prevent gumming of the type. It is obvious that the layers 1'? and 18 may be made more pervious than the layers 15 and 16, but to avoid complications during use, it is better to make all of the filaments of the same weight or thickness. As stated, so long as the protective film keeps the projecting fibers from being detached or being wiped over the surface of the paper, gumming and smudging need not be feared.

The ribbon shown in Figs. 5 and 6 is somewhat similar to that shown in Figs. 1 and 3, differing therefrom in the addition of a coating 22 to the paper side of the ribbon. It is apparent that other combinations or variations may be employed.

From these examples, it is apparent that an improved typewriter ribbon may be obtained which, although simple in nature, is effective to' prevent smudging and gumming of the paper, or type, in which uniform printing is obtained during practically the entire life of the ribbon, and wherein the ink supply or capacity is not materially diminished. It may be noted that improvements in typewriter ribbons, to be commercially applicable, must be of such a character as not to interfere seriously with customary business practices. The ordinary commercial practices and uses are now so well fixed that it would be impossible to utilize a typewriter ribbon which necessitated any material change in ofiice administration or in the habits of the operators in using the machines. Ribbons made according to the present invention do not require changes along these lines. The ribbon has the same effective life as the ribbons now commercially employed, and may be used in the same manner and for the same length of time as the old ribbons but with greater effectiveness and uniformity of the imprints produced throughout the life of the ribbon. No changes in typewriting equipment are required.

The ribbons may be made according to the customary methods of manufacture, and hence, may be produced at a reasonable price. For applying the very light and superficial open textured films which are preferred in combination with the limited area features herein discussed, use may be had of the apparatus disclosed in my copending application, Serial No. 349,208, filed March 22, 1929.

It will be understood that various materials may be employed to treat the fabric, and that various types of inks may be used. The particular concern of the present invention is in the provision of a protective film adapted to prevent smudging of the paper or the type and to produce clean cut impressions without excessive decrease of the ink absorbing capacity of the fabric. These objectives are obtained in the manner herein disclosed.

What is claimed is:

1. An inking ribbon having a textile body containing ink and having a protective film applied to the central portions only of the surface of said body and through which ink may pass from the underlying ink containing body of the ribbon, the marginal ink containing edge portions of the body being free from such coating.

2. A typewriter ribbon containing ink of a single color throughout its width and having a protective film formed over a portion only of .the printingside of the ribbon and along only one of a plurality of printing zones thereof and through whichfilm ink may pass from the body of the ribbon underlying said film covered zone.

3. An inking ribbon comprising a fabric containing the ink supply and a coating material IL through which ink may pass from the fabric, said coating being confined to a limited widthwise zone of the ribbon leaving the fabric uncoated at a margin of said zone to act as a reservoir to supply ink therefrom to said coatingcovered limited widthwise zone.

4. An inking ribbon comprising a fabric containing an ink supply, a coating material through which ink may pass from said fabric, said coating material extending along a limited widthwise portion only of the ribbon and covering only a part of that zone of the ribbon which supplies ink to said coating in order to leave uncovered portions of fabric at the margins of the coating to form a reservoir that supplies ink to said coating-covered portion of the ribbon.

5. An inking ribbon comprising a fabric containing the ink supply and a coating material on both sides of the inked surface of the ribbon through which coating ink may pass from the fabric, said coating on both sides of the ribbon being confined to a limited widthwise zone of the ribbon leaving the fabric uncoated at a margin of each of said zones to act as a reservoir to supply ink therefrom to the associated coating-covered limited widthwise zone.

6. An inking ribbon comprising a fabric having a limited widthwise portion only of its total absorptive capacity on the printing side of the ribbon occupied by a film forming substance through which ink may pass from the fabric and the uncoated portions of the ribbon adjacent to said film having an absorptive capacity occupied by ink and forming a reservoir to supply said film-covered portion.

7. A typewriter ribbon containing a plurality of inks of different color in spaced longitudinally continuous zones and having a protective film formed along one only of said longitudinal zones of the printing side of the ribbon and through which film ink may pass from the body of the ribbon underlying said film covered zone, there being uncovered widthwise areas adjacent to said protective film to form a reservoir to supply ink to the film covered zone.

8. A typewriter ribbon comprising a woven fabric inked ribbon protected along a restricted widthwise zone thereof which is struck by the type with a film forming substance through which ink may pass from the fabric and having unprotected widthwise areas adjacent to such film forming substance saturated with ink and forming a reservoir to supply ink to said film protected restricted zone.

9. An inking ribbon comprising a body portion of textile fabric saturated with ink and having the extreme surface portion only of its fibers treated with a light application of protective material sufficient only to fix projecting fibers without filling the interstices in the body of the ribbon, said protective material permitting ink to pass therethrough from the saturated textile body to the paper and being applied longitudinally of the ribbon along a portion only of the width thereof, uncovered widthwise portions of the ribbon adjacent to said protective material being saturated with ink and furnishing a supply to that portion of the ribbon covered by said protective material.

10. A typewriter inking ribbon comprising an absorbent textile fabric saturated with ink and having a face coated along a restricted width- Wise zone thereof with a wear resisting material previous to ink without impairing the absorbing capacity of the remainder of the ribbon, the ribbon having uncoated portions adjacent to said restricted widthwise zone which act as a reservoir to supply ink to said coated zone.

EDWARD W. SIBLEY.

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