DE8522C - Innovations in BELL telephones. SCHIEBECK & PLENTZ, mechanic, in Berlin - Google Patents

Description

1879.

Class 21.

SCHIEBECK & PLENTZ in BERLIN. Innovations in Bell's Telephones.

Patented in the German Empire on April 13, 1879.

The action of the Bell's telephone is based in the changes which the magnetism of a permanent magnet undergoes, when an iron membrane in the vicinity of a pole is made to vibrate. This effect is better with horseshoe magnets, with small pieces of iron attached to their poles on which the induction coils are plugged. It is the most possible Approach of the poles to one another with the greatest possible surface area of the same and the smallest possible Volume of the pieces of iron.

In the case of the No. 3396 patented telephone from Siemens and Halske are these conditions Filled by a horseshoe magnet with small pieces of flat iron at the poles are screwed tight.

In our construction we also use a horseshoe magnet a made of tungsten steel, to one pole of which we fasten a piece of soft iron b in such a way that it assumes a central position, while a ring of soft iron c is screwed to the other pole which is concentric with that inner pole; the shape of these poles, whether oval, circular or multifaceted, is rather indifferent, the concentricity is what is essential; It is only to be noted that the largest possible surface is created for the poles with a small volume, that their action is directed as close as possible to the center of the membrane and that there is enough space between them to be able to lay enough turns around the inner pole.

We have also provided our telephone with the following facilities:

The circular brass piece e is attached to the lower end of the horseshoe magnet and the brass ring / concentric at its upper end. These two parts fit exactly into a sleeve g, which in turn is provided with the usual wooden telephone mouthpiece h at the top and a base i at the bottom. By means of the screw k, which is surrounded by the small plates / 1 in a groove, the magnet can now be easily adjusted against the membrane, the central position remaining secured by means of the pieces e and /.

The exact setting makes it possible to determine the best effect of the device through tests.

The sleeve g is provided with sound holes mm which allow the vibrations of the membrane to express their sound effect both downwards and upwards and thus allow the latter to come into its own much better.

The clamping screw 11 shown in Fig. 4 offers an innovation that can be used for any purpose in electrical lines as well as in telephones. The wire is very often cut by the usual clamping screws, so we provide a screw with a central bore corresponding to the wire rods and with cross cuts along its length.

The threads of the screw η as well as its nut 0 are somewhat conical; If the nut is tightened, it therefore fixes the screw together inwards and clamps the wire inserted into the hole without damaging it.

In view of the above-mentioned facilities, our telephone responds so well that it can use one ordinary children's trumpet given a widely audible signal without any further devices can be.

Claims (3)

Patent Claims:. 1. See the arrangement on Bell's telephones a centric and an annular pole by means of attachment of two correspondingly formed iron pieces on a horseshoe magnet, each of which is wound with insulated wire, for the Purposes and in the manner as described and essentially as drawn. 2. The clamping screw with a central bore, cross cuts and conical Thread as described and essentially as drawn. 3. The overall arrangement of the. Telephones as drawn and described. 1 sheet of drawings.