Patent GB-190319553-A (GB)
Title: Improvements in and relating to Printing Telegraph Apparatus
Inventor: CASEVITZ HENRY
Filed: 1903-09-10
Granted: 1903-11-19
Abstract: 19,553. Casevitz, H. Sept. 11, A.D. 1902, [date applied for under Patents Act, A.D. 1901]. Telegraphs.-Relates to printing-telegraphs acting on the same general principle as that described in Specification No. 20,187, A.D. 1901. A clockwork motor is coupled at the point 2 to the shaft which bears the planet-wheels of a differential gear 3. The bevel-wheel 3<a> can turn to a limited extent against the tension of a coiled spring, which serves to take up shock when the shaft 31 is stopped, and to start it quickly when released. The shaft 31 carries the planet-wheels of a second differential gear 4, which transmits motion to the shaft 1, and also to the shaft 5 through the medium of toothed gearing 37, 38, 39. To the shaft 1 is secured a drum 7, Figs. 3, 4, and 5, which is normally connected to the adjoining loose drum 8 by means of a spring-pressed sliding plate 16 the projection 17 of which engages with a notch 20 in the crown 19. If this plate is pushed inwards, the adjoining drum is disengaged, and relative movement is allowed to the extent determined by the length of a slot 23 in which a stud 22 engages. The lengths of the slots 23 in the five drums 7, 8, 9, 10, 11 are respectively <16>/34, <8>/34, <4>/34, <2>/34, and <1>/34 of the circumference. The shaft 1 carries the type-wheel 6, Figs. 3 and 4. The drum 12 being normally held by a detent under the control of an electromagnet 69, Figs. 3 and 7, and the drums 7 to 12 being looked together by the plates 16, the shaft 1 and type-wheel 6 are prevented from rotating. If, however, one or more of the electromagnets 63, 64, 65, 66, and 67 are energized, the corresponding plates 16 are pushed in, and relative motion between the drums allowed, the movement thus given to the typewheel having any value from <1>/34 to <31>/34 of a revolution according to the combination energized. Fig. 7 shows the circuits at the receiving-instrument. Whenever a negative current reaches the polarized relay 62 through the line wire l, contact is made at 74, 75, and the circuit of the battery 71 is closed through the electromagnet 43, thus operating the pawls 42, and allowing the shaft 5 and brush contact 44 to advance by <1>/7th of a revolution. If a positive current is received, contact is made at 72, 73, and the circuit of the battery 71 is completed through the brush 44, contact plate 46 &c. on which the brush may happen to be resting, electromagnet 63, 64, 65, 66, or 67, a battery in the wire common to those electromagnets, and electromagnet 43. Five currents are sent to line in transmitting each character, and though all of them serve to space the shaft 5, only the positive ones actuate the electromagnets 63 &c., and control the movement of the type-wheel. This movement depends merely on the combination of the energized electromagnets, no synchronous devices being required. The shaft 5 makes a double stop at the end of the fifth signalling current, during which time cams 78, 79 effect the movement of the printing-hammer and the feed of the paper strip. Contact is also made at 52, 53, the electromagnet 68 being energized so as to release the drum 12, and effect the re-setting of the drums to zero under the action of a coiled spring 82 within such drum. A drum 13 fixed on the shaft 1 is arrested momentarily by a detent to allow the spring-driven drum 12 to restore the other drums to the zero position. The electromagnet 69 releases this detent as soon as the zero position is arrived at. The transmitter may be of the form described in the Specification quoted above, or each character may be transmitted by five movements of a simple reversing-key. Fig. 18 shows a "Baudot" transmitter in which the five keys 105 are adapted to send positive or negative currents according as they are raised or depressed ; when they have been set the brush 98 sweeps over the contact plates 100 and sends the currents to line in succession. In the device shown in Fig. 19, each key 112 sends the series of currents for one particular character, the transmission being made as the contact-piece 116 carried by the spring 114 returns past the contact rods 121 on the release of the key. The insulating-piece 115 prevents contact during the forward stroke. The number of characters that can be transmitted may be increased without increasing the number of drums by providing means either for giving the type-wheel a slight rotation to bring intermediate type into play, or for shifting it laterally to print from a second ring of type.