The Autodial for Telephones

Abstract

TELEPHONE subscribers connected to automatic exchanges who use their instruments frequently will soon be able to obviate in many cases the necessity of making the dialling operations. On the London automatic exchanges, the ordinary number of opera tions to be carried out is seven. By means of the new autodial, these operations can be reduced to two. The device is contained in a small box on the face of which there is an index of the names of the subscribers most frequently called. When anyone whose name is oh this index has to be called, all that has to be done is to set the pointer of the instru ment opposite the name required and depress a lever. There is no change-over switch and the instru ment does not in the least interfere with the normal use of the telephone. Any number not on the index can be called by the usual method of dialling. The index names correspond with toothed discs, the teeth of which are cut away to form a transmitting code of impulses corresponding to the number selected. The discs clip on to a rotating cylinder so that the combination can be easily changed when necessary. The depression of the lever winds the cylinder sufficiently for one revolution and this is sufficient to generate the train of impulses necessary for com pleting the call. We understand that subscribers will be able to hire an autodial for a few shillings quarterly. It is made either for 25 or 50 names. For business houses and intercommunication systems, special forms are made. The distribution of the instruments for private installations is made by Dictograph Telephones Ltd., Aurelia Road, Croydon.