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• REF ID:A7041. 

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Patented Apr 24, 1934 1,956,384: 

UNITED ST A TES PATENT OFFICE 

1,858,884 

POCKET OBYPTOGBAPBIO APPARATUS 

Albert Gentet. ........ :France 

Application December 1. 1881, serial No 5'8,17B 

In France February 4, 1831 

1 Claim cm s&-1§) - ....... _ .... 

M1' fD.venb.on relates t.o unprovements m pocket 

cryptographic apparatus wit'1 permutable slides 

The improved apparatus essenb.ally comprises a suitable number of rack-llkc slides all of wbJ.ch 

o are fD.terchangeable and each of which carries a numeral and the letters composing the alphabet, 

the inscribed numerals bemg all dlfrereJ;lt and the 

letters consb.tuUng the several alphabets being 

all disposed dJJferentJy the one with respect to 

10 the others on the various slides 

These slides which can be coupled together m pairs by thell' extremib.es may be caused to 

sllde fD. grooves formed m a base member by means of toothed pmions controlled by swtable 

11 spfD.dles fD. such a manner that for each of the 

groups of two coupled slldes all the letters car- ried. by these slldes can simultaneously and re- spectively pass m front of two reference marks 

which are provided on the base member perpenIO dlcularb' to said slldes fD. such a manner that a letter of the one corresponds to the letter on the 

same row of the other 

The accompanyfD.g drawings show by way of 

example cmiy one embodiment of the mvention 

II Flg 1 JS a dlagramma.tlc transverse secb.on of 

the base member, 

Fig 2 ls a top plan view thereof 

Fig 3 ls a bottom plan VJ.CW thereof 

Fig 4 shows a slide both in plan view and side 

80 elevation 

Fig 5 ls a top plan V1ew of the complete apparatus and 

Plg 6 ls a top pla.n view of the apparatus mus- tratlng the making of a cryptogram 

811 On the cirawmirs 1 JS the grooved base member 

havmg m the embodiment shown ten parallel 

groovei 1• (Flg 1) 1n wluch the twenty rack slldes 

2 assembled 1n pairs by means of their ends aa are free to sllde CPJ.gs 6 and 6> '° lb fD.dica.tes slots formed m I.he bottom of each 

groove to accommodate pinions 3 mesbmg with 

the rack teeth of the slldes 2 At 4 are mcilcated 

operatmg knobs for tubular spindles 6 control411 hng five of the plmons 3 the other five thereof 

being controlled by solld spindles 6 passmg 

through the tubular spmdles 6 and provided with 

knobs 'l wbJ.ch are coaxial with the knobs 4 

(Flg 1) -

50 8 fB a protecb.ve camng malntalmng the spfD.-

dles and plnlons fD. place (Fig 3) 

At 9 are fD.dlcated members which serve fo1 

the mounting on the base member 1 perpendlcularb' to the grooves 1• of two reference marks 

15 10 and 11 consb.tuted by two lenses extcuidlng across the slldes and bemg transparent over a 

:narrow and well de1lned zone m their central portion the margmal portions being either depolished or roughened or otherwise obscured as by 

60 colouring 

The operab.on of this apparatus Wl11 be readlly 

understood 

Plrst the twenty slldes 2 coupled together m 

P&ll'S are pushed mto the ten grooves 1• of the 

base member 1 (Pig 6> m such a manner that 85 

the order numerals of the head slldes and of the 

tall shdes form the sequence of numbers which 

bas previously been agreed upon between the cor- respondents 

The cryptogram Is then produced. m I.he follow- 70 

ing manner 

Assuming that the text "Cours du lln" (Flg 6) 

JS to be ciphered the knurled knobs 4 and 'l are 

operated in such a manner that in the central 

part of the ieference mark 10, provided for the 75 

head slldes, t.here appear successively the letters 

C for the first sllde from the left 0 for the sec- ond and so on to the letter N for the last slide 

By reason of the above mentioned coupling, 

the tall slides have also been displaced durmg so 

the preceding operation and the cryptogram has 

appeared m the central part of their reference 

mark 11 in this CaSe "K8.adrrorial" (Pig 6) Any 

other cryptoguuns for the same text could be obtained by mod.lfymg the permutation of the 815 

&lldes The number of dlfferent cryptograms 

which could thus be obtained. ls equal to the num- ber of mnple permutations of twenty numerals, 

namely 

2 432,902 008 1 '16 640 000 80 

The cryptogi am can be de01phered by preparmg the apparatus as for cipher.mg 1 e by prodUClng the same permutation of the slldes and 

then caUSlllg the successne letters of the cryptogram to appear m the reference mark 11 of the 95 

tall slldes 

The deciphered text Wl11 then appear fD. the 

reference mark 10 of the head slldes 

It will be understood that va"lous modJ:ftcab.ona 

may be made m the apparatus without a depart- 100 ure from the scope of this invention For ex- ample the number of slldes employed may be 

vaued and the control knobs with the spmdles 

of the pinions may be otherWlS8 disposed or re- placed by other suitable operating gear 1o;s 

I c1aun 

For use in cryptogi apb.J.c devices exchangeable symbol ca.rrymg slides havmg opp0S1tely dlrected. 

hooks at opposite ends whereby to permit the 

slldes to be qwckly coupled o.n.d uncoupled for no 

making up mter-changeable sets and a grooved 

base part for receiving said sl.J.des 

ALBERT GENTET 

115 

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• REF ID :A70410. 

April 24, 1934. A GENTET 1,956,384 

POCKET CRYPTOGRAPHIC APPARATUS 

Filed Dec 1, 1931 2 Sheets-Sheet 1 
• 

Apnl 24, 1934. 

Fi.g- 5 

REF ID:A70410 • 

A GENTET 1,956,384 

POCKET CRYPTOGRAPHIC APPARATUS 

Filed Dec l, 1931 2 Sheets-Sheet 2 

fi9-6