Patent GB-190708095-A (GB)
Title: Means and Method of Recording Speech or Sounds in Visible Characters.
Inventor: CHRISTOF PETER
Filed: 1907-04-06
Granted: 1908-03-26
Abstract: 8095. Christof, P. April 6. Typewriters and like machines. - An apparatus is described for transforming spoken speech into legible characters. A microphone communicates with two telephones the diaphragms of which operate contacts connected to the levers of a typewriter. The transmitter (not shown) consists of a battery, microphone, and an intensifying induction coil, one lead L, Fig. 2, being connected to the first telephone T<1> of the receiver which may be at any distance from the transmitter, the other lead from which is earthed. The telephone T<1> is connected inserted with the telephone T<2> by a lead l<3> and is then earthed by the plate shown. The movements of the diaphragm m of the telephone T<1> are communicated by a tube containing liquid to a plunger K and thence (magnified) to the end d of the rocking lever H, the spring f keeping the plunger K in contact with the liquid. When a sound is about to be typed, the end d closes one of a set of contacts on an insulating plate P carried by the rocking lever p<1> ; the circuit comprising the battery b, the arm d, one of the leads l<9>, one of the electro-magnets e, lead l<4>, and the electro-magnet u, is thus completed and a type-lever t operated by one of the electro-magnets e makes a record on the band N. The core k<1> of the second telephone T<2> is connected through another battery b<1> to an electro-magnet E<2> operating the band-feeding apparatus W next to the interrupter U, operated by the current of the previous circuit, and thence to the electro-magnets R and the metallic diaphragm m<1>. Vibration in'the telephone T<2> makes contact between the diaphragm m<1> and the core k<1>. Since the contact x in the interrupter is closed, the battery b<1> is able to energize the electro-magnets R. These move the armature-lever p<1>,and it is the combination of this movement with the commencing oscillation of the point d, the nature of which depends upon frequency and amplitude, that enables the correct contact on the plate P to be selected, that is the correct character to be typed. The paper band N has been advanced between the typing of each letter by the pawl z on the armature A, the advance being checked at the operation of a typelever t, by contact at x being broken by the current acting in the electro-magnet u of the other circuit. This breaking of contact at x also releases the spring- controlled lever p<1>, the end d being thrown out of contact. (The interrupter U is unnecessary when the diaphragm m<1>, or spring which may take its place, can be relied on to break contact with the core k<1> immediately on cessation of current disturbance in T<2>.) As there is then no current in the circuit containing the coil u, a spring causes contact to be again made at x and the armature A again operates the ratchet, having previously been thrown up by the spring f on the breaking of contact at x. The apparatus is thus ready for the next electrical impulse. A modification of the receiving-apparatus is shown in Fig. 3, in which the telephone T<2>, the interrupter U, and the battery b are dispensed with. The plate P is made of conducting material and the contacts on it are insulated, the end d when the apparatus is riot working also resting on an insulated part to save current. Further modification may be made by mounting the plate P on flat springs and placing the coil R so as further to increase the amplitude of vibration of the lever p<1> ; or the point d may form part of the plunger rod. Twin type-levers are used for dipthongs.