US1320634A - Jacob a - Google Patents

Description

J. A. L. MULLER.

TYPE WRITING R|BBON. APPLICATiON FILED MAY, 1919.

1 20,634. Patented Nov. 4, 1919.

-INVEN OR I (v zier ATTORNEY JACOB A. L. MOLLER, OF NEW YORK, N. Y., ASSIG-NOR TO ROSE & FRANK COMPANY, A.

CORPORATION OF NEW YORK.

TYPE-WRITIIjT G RIBBON.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed May 14, 1919. Serial No. 297,089.

is to produce a better ribbon, one which will lieflat in use.

In the drawings, which are merely illustrative,

Figure 1 is a portion of a ribbon (threads exaggerated), and a Fig. 2 is a schematic representation of a gum-applying machine which may be used.

Heretofore typewriter ribbons have been made of awoven cotton fabric, and woven silk has been proposed, but as made they are open to various objections, and no. adequate diagnosis seems to have been made of the underlying causes of some of the defects inherent 1n them, or of the remedies for such defects.

A typewriter ribbon, to be entirely satisfactory, must lie flat on the machine, not only when first applied but when subjected to the pounding of the type and atmospheric changes. If it wrinkles, due to unequal-contraction or other causes, it gives trouble. It must be very-thin and flexible, and should not be unduly aifected by atmospheric moisture.

A cotton fabric woven in a narrow strip has been used, and silk of some indefinite kind and characteristics has been proposed, but when woven into a narrow strip each is open to various objections. The cross threads then consist of one long thread woven back and forth. This consequently is doubled 0r looped at the edges and this results in various objections. The looped end when it is sharply doubled back is likely to break and fray, especially when run through the guides, and give passage atmospheric moisture in the threads as well as the pores of the fibers themselves. Most (ribbons are run in a substantially vertical plane, and one edge rests on the guides. It therefore soon wears and frays. Also, the frayed ends soil the paper, catch on the guides, and are otherwise objectionable.

Cotton is very hygroscopic. If a narrow ribbon having cross threads with the ends not looped but raw (cut ofi') and untreated, were used, the defects of the doubled ends would in part be avoided, but other even more objectionable results would occur.- Atmospheric moisture passes, as in the above illustration of a frayed looped thread, resulting in various troubles such as decay, contraction of one or both edges, and an uneven or possibly wrinkled ribbon which will not lie flat and which brings still more friction thereon in the guides, and the ribbon soon goes to pieces at its edge. A typewriter ribbon usu-ally comes in a closely fitting tin box, the ribbon itself being further protected by a wrapping of tinfoil. These precautions to a great extent protect the ribbon until it is put on the machine, but once in use it is exposed to the atmospheric moisture, which greatly varies in quantity, and consequently the ribbon usually has a short life. I have discovered that a ribbon principally composed of fine animal fiber, preferably silk, when properly treated as herein described, results in one which has several advantages, and avoids Objections inherent in ribbons of the prior art. By silk I do not mean necessarily entirely composed of silk.

I prefer to use a fine closely woven silk from 3 to 5 one thousand-ths of an inch thick, in a strip substantially the width of the completed ribbon, and with the cross threads raw (cut) at each end. A portion of such a strip is shown in Fig. let A. The strip may be cut from a wide sheet. I may smooth, calender, or iron the fabric, but this is not always necessary. I- also prefer that the threads be loosely twisted, because theribbon will wear longer than when they are hard or tightly twisted. It is also more absorbent of ink.

Then I impregnate the raw ends of the threads with a fluid or liquid gum which is flexible and substantially non-hygroscopic when dried. This lays the ends and binds them continuously to each other, as shown at E, F, in Fig. 1, and, what is important,

prevents passage of moisture in the ends of as flexible as the silk alone.

thereto a small quantity of glycerin or its equivalent to make the resultant gum mixture more flexible when dried. The fluid gum may be applied by passing the strip between pressure rollers C, D, as shown in Fig. 2-, if desired, the gum bein fed to the rollers or by a rotary knife suita ly gummed. The strip is then dried.

Rawsilk is very hygroscopic. In its natural or untreated state it has considerable ceresin in Or on it. I prefer to remove this, or a considerable amount of it, as I find the ribbon resulting has a better surface, takes ink more readily and in greater quantity, the threads slip on each other, and has other advantages Also, the gum seems, to set or take hold of thefibers better. The ceresin may be removed, preferably before weaving,

by boiling the silk in a soft-Water (nonalkali) soap solution.

The ribbon made as above is perfectly flat, is substantially non-hygroscopic at its edges, takes ink readily, and is not so subject to contraction or other defects due to moisture. .Its edges when properly treated are firm and smooth, and'will not so readily wear out, but yet are almost, if not quite, It has other advantages. v

I am aware that my invention may be em- .bodied in avariety of forms other than the examples above given, and the. claims hereto appended are not intended to be limited to all the details heretofore described. What I claim is:

1. A ribbon of the character described, I

comprising a strip of thin fabric made of fine animal fiber, each cross-thread terminating in a raw end at each edge of the strip, and a continuous flexible dried gum impregnated in said raw ends along each edge, thereby binding each raw end to the others and closing the ends of the threads against passage of moisture.

. 2. A ribbon of the character described, comprising a strip of thin silk, each crossthread terminating in a raw end at each edge of the strip, and a continuous flexible dried gum impregnated in said raw ends along each edge, thereby binding each raw end to the others and closing the ends of the threads against passage of moisture.

3. A ribbon of the character described, comprising a strip of thin silk from which the'ceresin has been at least partially, removed, each cross-thread terminating in a raw end at each edge of the strip, and a continuous flexible dried gum impregnated in said raw ends" along each edge, thereby binding each raw end to the others and closing the ends of the threads against passage of moisture.

4. A ribbon of the character described,

comprising a strip of thin fabric made of animal fiber loosely twisted, each crossthread terminating in a raw end at each edge of the strip, and a continuous flexible driedgum impregnated in said raw ends along each edge, thereby binding each raw end to the others and closing the ends of the threads against passage of moisture. v

Signed at New York city, N. Y., this-8th day of May, 1919. l

' JACOB A. L. 'MOLLER;

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