Untitled record

Application filed September 12, 1884. (No model.)

To all wham it may concern:

Be it known that I, David R. Smith, of Cohoes, county of Albany, and State of New York, have invented a new and useful Improvement 5 in Combination Cipher-Machines, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification.

This invention relates to that class of comio bination cipher-machines in which series of letters, figures, words, signs, or symbols in regular order, and having their usual, customary, and generally-understood significance, are brought into juxtaposition with series of 15 the same or other signs, symbols, or characters capriciously or irregularly arranged in such manner that the latter may be conveniently used as secret characters or ciphers to represent the former in secret correspondence, 20 or for other similar purposes.

The object of the invention is to provide an improved combination cipher-machine for general use which shall be susceptible of a practically unlimited number of combinations, 25 more so than the combination-locks used to secure the doors of safes and bank-vaults, whereby, no matter h ow many persons may use this invention, each pair of correspondents may by its aid be provided with a cipher-code 30 different from every other such code, and practically impossible to decipher by any one not possessing the key.

For the purposes of this description of my invention I will designate the letters, signs, 35 words, phrases, characters, symbols, &c.,when employed with their usual or customary meaning or significance, as conventional letters, signs, &c., and the same or other letters, signs, symbols, characters, &c., when employed to 40 represent the former, or as representing the former, as cipher letters, words, symbols, &c.-—that is to say, when given an arbitrary or unusual meaning or significance I will designate them as cipher letters, words, figures, 45 symbols, &c., or simply as cipher.

My invention consists of a machine in which conventional letters, as the alphabet, or conventional numerals, as 1 2 3 4 5 6 7 8 9 0, or other conventional characters, signs, words, 50 symbols, &c., are arranged in their usual or regular order, in a direct line, or in direct or

I straight lines, across the faces of a series of coI axial cipher wheels or disks, the said cipher wheels or disks carrying the same or other letters, figures, signs, words, characters, &e., 55 to be employed as ciphers or characters to be used in secret correspondence, and to represent the conventional signs, characters, or symbols, &c., with which they are, by the preconcerted movement of the parts of the ma- 60 chine, brought into juxtaposition.

While for especial purposes any suitable signs, letters, characters, words, symbols, &c., may be employed in my invention, the twentysix letters of our alphabet and the numerals 1 65 234567890 will suffice for general purposes.

In the accompanying drawings, Figure 1 is a front elevation of a machine embodying my invention. Fig. 2 is a transverse section 70 through the center of the same. Figs. 3 and 4 illustrate certain modified details of Figs. 1 and 2. Fig. 5 is the letter cup or box, and Fig. 6 represents a front and an edge view of a letter-block. Fig. 7 is a plan, Fig. s I a elevation, and Fig. 9 details, of a modified form of the machine shown in Figs. 1 and 2.

In all the figures A is the bed-plate, B the cipher-wheel shaft or axle, a' d² a? a¹, &c., are the cipher-wheels fitting loosely ou that axle, and having not ches δ δ, which engage the hooked ends of stop springs or pawls c c. C C C are thumb-nuts, which, working in screwthreads cut in the cipher-wheel axle B, clamp the cipher-wheels together, when required, so 85 that all the said wheels a a will turn with the axle B, or when the thumb-nuts are turned iu the opposite direction will loosen the cipherwheels and allow eacli and all of them to be turned freely about the axle. In Figs. 1 90 and 2 the axle B is horizontal and supported by uprights dd in bearings ee. In Figs. 7, 8, and 9 the axle B is vertical, and is firmly secured to the bed-plate at or near the center of that plate. 95

In Fig. 1, E is a hand-wheel for turning the axle, and F a friction-wheel upon which the adjustable friction-brake G bears, the pressure of said brake being regulated by the adjusting-screw II as required. The stop springs 100 or pawls c c project from a bar, f. In Figs. 1 and 2, the bar/is pivoted to uprights gg, and

312,665 is provided with an adjusting-arm, h. i and J are adjusting - screws, the former working against and the latter screwing into the bedplate. By manipulating screws i and j it is 5 evident that the tension of springs c c can be readily regulated.

In Fig. 7 no means of adjusting or changing the tension or pressure of springs care shown, . as any suitable means may be employed for io that purpose.

In Figs. 1 and 2 the broadened ends of the springs c are utilized to carry the conventional signs or characters, which in . this case are the alphabet and numerals, as shown, in a direct 15 line across the faces of the disks a' a² a^s cl¹, &c.; but the spring-pawls c c may be placed in a different position, or may be suitably modified in form,and a straight-edge or blade, I, be employed to carry the conventional characters, 20 &C.

The blade I in Fig. 3 is provided with lugs or projections Z, by which it may be secured to the bed-plate A. In Figs. 7 and 8 the blade or straight-edge I is divided in two parts, 25 Γ I², to avoid the employment of other .ten wheels or disks a, to correspond to the numerals. The same economy of wheels or disks a may be effected, if desirable, in Figs. 1 and 2, by the use of an independent straight-edge, Γ, 30 for the numerals—that is, by dividing up the straight-edge I in that figure and using twenty-six, instead of thirty-six, wheels or disks a. In Figs. 7 and 8 the blade I is carried loosely between the thumb-nut C and a washer, m, as 35 is clearly shown in Figs. 8 and 9, and at its outer extremity the blade I bends around the outer edge of a steady-disk, J, and carries a thumb-screw, K, by which it may be tightened anff held stationary, or loosened to swing 40 around the faces of the disks or wheels a a, from one to another of the radially-disposed lines of cipher letters or characters on the disks or wheels a. Upon the faces of all the wheels or disks a, as in Fig. 1, or near the (.5 outer edges of the wheels or disks a, as in Fig.

7, the cipher letters, signs, symbols, or characters, &c., are arranged.

In the examples shown in the drawings, and for general use, I employ as signs, characters, 50 symbols, &c., the twenty-six letters of our alphabet only; but any suitable characters or symbols, words or signs may be employed for general or especial cases or purposes.

In the drawings only a part of the letters 55 are shown. All the wheels or disks a in Fig. 1 are exactly alike, and each has a full alphabet on its face, all the letters of which are arranged in regular order and evenly spaced from a to z, the letters of the first twenty-six 60 disks corresponding as ciphers to the letters of the alphabet, as conventionally employed, and shown in the direct or straight line across the faces of the disks «, and the letters on the other ten disks corresponding as ciphers to 65 the numerals 12 3 4 5 6 7 8 9 0 in a similar manner.

In Fig. 7 the wheels or disks a—only twenty six in number—are lettered in similar order; but to reduce the number of wheels from thirtysix to twenty-six the letters brought into jux- 70 taposition with the conventional numerals 1 2 3 4567890 on the blade or straight-edge Γ are used as cipher-characters representing these numerals.

The letter-blocks and letter-cup shown in 75 Figs. 5 and 6 are convenient for the purpose of selecting series of letters by chance when using my invention. The letter-blocks are any small disks or pieces of convenient size and form upon which the letters of the alpha- 80 bet appear.

I will describe a simple manner of using my invention. Let us suppose that a merchant, X, of a certain city, having the machine as shown in Fig. 1, wishes to carry on a secret 85 correspondence with another merchant, Y,. who resides in some other city, and who also is provided with an exactly similar machine. The first thing required is that X and Y agree upon a cipher-alphabet, which shall be a key 99 with which to set the machine. This can be done by chance very conveniently with the aid of the letter-cup and letter-blocks shown in Figs. 5 and 6. They may shake the twentysix letter-blocks in the letter-cup and throw 95 them out on the table, as shown in Fig. 5, then select the letters, by chance, or “as they come,” thus forming a key-cipher alphabet. Then return the letter-blocks to the letter-cup and shake the latter again and select ten more 100 letters to serve as cipher-numerals. Let us suppose that the cipher letters and numerals selected by X and YareZvfpghmrs w u tjknbzoqdxaicey for the twenty-six letters, and 0 g m d Z y c k f r for the ten 105 numerals. Let it.be agreed between X and Y that the cipher-alphabet shall be changed for every word written in any secret communication between them. Then, to use the machine to write or to read the written cipher no the machine must be set, as shown in Fig. 1, with the key-cipher alphabet and numerals forming a straight line in juxtaposition with the conventional alphabet and numerals, as shown in that figure. ^TI5

To write, as by agreement, between X and Y, the first word would be written with the key-cipher alphabet shown in Fig. 1, the wheels having been previously clamped firmly together between washers p, by screwing up 120 the thumb-nuts C C after setting the disks, as shown. To write the second word, X or Y would move all the disks together one letter or more, according to previous agreement, or until the spring-pawls e c pass from one line 125 of notches into the next succeeding line or other line, as agreed, and so on for each succeeding word, turning the clamped disks around one notch, or more, as before, and using for each word a new cipher-alphabet 13⁰thus broughtinto juxtaposition with the parallel straight line of conventional letters. The modification shown in Fig. 7 is used in a similar manner, except that the arm or straight

312,665 edgel² does not require anykey, it being governed by I', and therefore the key-alphabet of such an instrument would consist of twentysix letters only.

To use this invention for carrying on secret correspondence between parties at a distance, it is necessary that both parties have machines exactly alike, in practical detail, that the alIjhabetical key or some other key be agreed io upon to set the instruments alike and to govern the changes to be made when using the machines, either in writing or deciphering a secret communication; but it is evident that the number of combinations and changes pos15 sible is limited only by the permutations of which the alphabet employed is susceptible; and having given one of the most simple ways of using this invention it is evident that every one using it can select his own methods in 20 the way of deciding on an alphabet,or selecting a key,or in changing the cipher or the significance of the cipher used.

By preparing a code in which a few letters represent many words and using the conven- j 25 tional letters to represent such words and the cipher-letters to represent the conventional letters a great many words maybe communicated in perfect secrecy with a very few cipherletters. For example, let a key-book be pre30 pared in which write one thousand phrases numbered from 1 to 1,000. Then it is evident that any one of these phrases may be commu. nicated with from one to four cipher-letters rep’resenting the number of the prase.

In manufacturing my cipher-machine for sale for general use the thirty-six-disk machine should be provided with an extra blade or straight-edge, Γ, so arranged as to correspond in position with the blade I² on twenty40 six-disk machines, so that not only all twentysix-disk machines will correspond with each other, but the first twenty-six disks of the thirty-six-disk machines having the blades I' and I², or the equivalents of such blades,will 45 virtually constitute a twenty-six-wheel machine.

To distinguish between the cipher-letters representing conventional letters and those repvesentiug conventional numerals, any con50 venient sign agreed upon may be employed, such as simply underlining the numerals.