Patent GB-190517023-A (GB)
Title: Improvements in Cryptographic Machines.
Inventor: BURG HUBERT
Filed: 1905-08-22
Granted: 1906-03-22
Abstract: 17,023. Burg, H. Aug. 22. Typewriters. -Relates to a cryptographic typewriter in which a type - cylinder or its equivalent receives a predetermined series of angular movements relative to its shaft, for ciphering or deciphering. Figs. 2 and 3 show machine having fast and loose typecylinders 1, 2 on a common shaft 3, the fast cylinder 1 giving the letter text, and the loose cylinder r 2 the ciphertext, in ciphering, or vice versa in deciphering. The keyboard mechanism may be such as that described in Specification No. 21,237, A.D. 1900; the only parts shown are the grooved disk 6 and lever 7 for effecting longitudinal movement of the shaft 3. The loose cylinder 2 is disposed between two fixed rings a, a<1>, and is provided with teeth a<2> for cooperation with toothed segments b<5> b<6>, and with holes a<3> for locking by means of a pivoted spring-retained dog a<5>, which is withdrawn when the cylinder 2 is moved up against the framing 4. The segments b<5>, b
 are on a plate b<4>, adjustable on a lever b<1> in two positions, determining which segment shall engage the teeth a<2>, for ciphering or deciphering. The lever b<1> is retained by a spring b<9>, and carries two grooved segments b<2>, b<3> for alternative connexion by a chain c to a grooved segment c<2> turned from a lever d alongside the keyboard. The lever d carries a grooved segment d', connected by a chain d<2> to a grooved disk d<3> provided with a pin d<4> for driving the segment c<2>. The disk d<3> is connected by a chain d<5> to a balance d<6> and spring d<7>. The movement of the segment c<2> is limited in a variable manner by means of a pin e fixed on the segment c<2>, and stop pins e<1> adjustable on a ratchet-disk e<2>, actuated from the disk d<3> by means of a pin f<6>. and pawl mechanism f<5>, f<4>, f<3>, f. The shaft 3 is shifted longitudinally, to bring the parts a<2> and b5 or b<6> into gear, by operation of the lever 7 from the disk d<3> through an incline, lever, and cbain(notsbown). It is essential that the segment c' should not return until the disk d<3> has returned sufficiently to withdraw the shaft 3, and, for this purpose, a ratchet wheel on the segment c<2> co-operates with a spring-retained pawl h,which is withdrawn by the pin d<4>. The cipher factors are the initial position of the disk e', the arrangement of the pins on the disk e<2>,and the, initial relative setting of the cylinders 1, . 2. The position of the disk e' is determined by means of graduations on the disk e' and a pointer e<5> on a fixed dial e<6>. Fig. 8 shows a modification. The segments b<5>, b<6>, Fig. 3, are replaced by straight racks b<10>, b<11>, adjustable on a slide b<14>, the upward movement of which is limited by engagement of a heel b<17> with the stops on the disk e<7>. The slide b<14> is raised, against the action of a spring h<5>, by means of a pivoted spring-tensioned dog c<4> on a lever c5, which is actuated by means of a cam c9 on a keyoperated spring-returned rock-shaft c<10>. The disk e<7> is advanced by means of a pawl f<11> on a slide f<12>, actuated from a cam f<19> 19 on the rock-shaft c'‹. The shifting of the shaft 3<a> is effected from a third cam g<6> on the shaft c'‹. The slide b<14> is maintained in the raised position by means of teeth h<6> and a pawl h<3>, tensioned by the spring h<5> and released by the slide f<12>. The number of possible combinations. may be increased by using a cipher cylinder composed of adjustable type disks or rings.