Patent GB-189715838-A (GB)
Title: Improvements in or pertaining to Multiplex Printing Telegraph Systems.
Inventor: JUSTICE PHILIP MIDDLETON
Filed: 1897-07-03
Granted: 1898-07-02
Abstract: 15,838. Justice, P. M., [Rowland, H. A.]. July 3. Synchronous movements; telegraphs. - Consists of a printing-telegraph system with a multiplex d i stributer working with alternating currents. E a c h complete s i g n a l consists of the modification, by inversion or omission, of two or more semicycles of the alternations of the current. The alternating impulses may be derived from any suitable source. The alternations are divided up into cycles of predetermined number and every complete signal of the code adopted is completed within a cycle. Each transmitting-station is provided with a number of branches corresponding to the number of elements of the cycle, and these branches are connected to a distributer by which the signals are transmitted to line. Various arrangements of these circuits are described, the preferable arrangement being that in which the makes and breaks occur in local circuits and affect the alternating currents of the main line through a relay, the distributing action at the receiving-station being also accomplished by means of a relay and distributer the local circuits of which contain the requisite number of combination relays. The transmission may take place either by means of a perforated tape with one or several rows of perforations, or by a keyboard in which all the key levers operate a number of contact-levers in the predetermined combinations. In this instrument a locking-lever is provided for preventing the depression of a second key before the signal of a previous key is completed. Fig. 14 shows an arrangement of the apparatus in which B is the synchronzing-apparatus, consisting of magnets B<2> in the field of which runs a double disc armature B<1>. One face of the armature has continuous-current driving-coils, while the other face has alternating-current regulating-coils. These coils may be either in the main circuit or relayed from the main circuit. The brushes for the commutators B<4> consist of springs attached to pivoted frames having weighted pressure levers. The synchronizing-shaft is connected by gearing to a hollow shaft F through which a shaft K passes. The shafts F and K are geared together by adjustable bevel gear F', F<0>, K<1>. The shaft K carries the rings 0, 0 for connecting the line to the transmitting and receiving brushes of the distributers D<11>, D<12>, J being a cable formed of the leads attached to their segments. The distributers are adjustably mounted, and form a bearing for the end of the shaft K. The other end of the shaft K carries a contact-arm F<3> which bears on the divided disc N. The divided disc N forms a regulator for maintaining the speed of the motor E synchronous with the motor B. The shaft P driven by the motor E carries the combination device, consisting of the segment discs D<4>, D<5> having adjustable brushes C<3> and the collector rings d<2>, d<10>, and the type-wheel W'. The printing-hammer is operated by the magnet M in circuit with the tongue of the relay R<x>. The hammer itself is pivoted so as to move slightly with the type-wheel, and the type-wheel is provided with a coiled spring, so as to be retarded at the moment of printing, and when released to take up its normal position. The heel of the printing-lever closes one circuit of the relay R<xx> which controls the paper-feed magnet Z<0>, and at the same time resets the relay R<x>. The action of the paper-feed lever also resets the relay R<xx>. In the system of duplexing described the bridge connection at the receiving-station contains the synchronizing-device and one of the relays. The receiving-bridge may also be omitted, the two relays being arranged with the armature of one and the magnet of the other connected in series to the line, and also having the synchronizing-device in series. Several arrangements of the distributer segments are described for use when only two elements are used in a combination, and when two, three, or four elements are employed. The relay R<000> is the polarized line relay, and is preferably constructed with its armature consisting of a pivoted coil wound on a core arranged in unstable equilibrium, the contact lever being attached to the pivoted coil. When multiplex working is adopted, each distributer is provided with a number of groups of contacts corresponding to the number of signalling-operators.