US274352A - Receiving-telephone - Google Patents

Description

(N0 Model.) I

J. A. MALONEY.

- RECEIVING TELEPHONE N0. 274,352. H Patented Mar.20.1883. v

UNITED STATES PATENT JAMES A. hIAIiONEY, OF \VASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO S. H. CARNEY, TRUSTEE, OF NEW YORK.

RECEIVING-TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 274,352, dated March 20, 1883.

Application filed January .2, 1883. (No model.)

To all whom it may concern Be it known that I, JAMES A. MALONEY, of Washington city, in the District of Columbia, have invented certain new and useful Improvemerits in Receiving-Telephones, of which the following is a specification.

My invention has for its object to increase the efficiency of receiving-telephones. 1n the instrument devised by me there is combined to with the diaphragm an electro-rnagnet which is in the line-circuit, and is provided with a tubular longitudinally-slit soft-iron 'core. In other words, the core of the electro-inagnet, instead of being solid, is a hollow cylindrical shell, which is slit lengthwise on one side from end to end, the contiguous edges bounding the slit being out of contact with one another. A core having these characteristics acts to reproduce the voice with great distinctness, and renders the instrument sensitive and very efficient. Inasmuch as a soft-iron core elon gates when magnetized, and variations in magnetization or alternate magnetization and demagnetization will result in corresponding variations in its length, and, further, as it is reasonable to suppose that increase in its length is accompanied by corresponding decrease in its cross-section, and vice versa,it is not improbable that these changes in the tubular core are 0 permitted more readily and quickly to take place by slitting it lengthwise; but, however this may be, the fact remains that a core possessing the characteristics above stated is very much more efficient than and produces results that cannot be obtained by the employment under similar conditions of either an unslit tube or a solid core. In my receiving-instrument the electro-magnet is intermediate between the diaphragm and the ear opening or trumpet, and the tubular core thus acts in a measure as a resonator-tube. In practice I have found that the etficiency of the instrument is enhanced materially by forming in the tubular core, in addition to the continuous 5 longitudinal slit, a series of slits extending lengthwise from each end of the core toward its center in length-say about one-third of the length of the core, more or less. This construction allows the core to be polarized and depolarized more rapidly than otherwise would be the case.

The nature of my invention and the manner in which the same is ormay be carried into effect will be readily understood by reference to the accompanying drawings, in which- 5 Figure 1 is a longitudinal central section of the receiving-telephone. Fig. 2 is a section on line 00 m, Fig. 1. Fig. 3 is a section on line yy, Fig. 1. Fig. t is a perspective view of the instrument. Fig. 5 is a perspective view of the diaphragm and its rubber washer. Fig. 6 is a side elevation of the electro-magnei. Fig. 7 is a perspective view of the tubular longitudinally-slit core. Figs. 8 and 9 represent a modification ofthe core. Fig.8 shows in plan the 6 flat metal sheet, and Fig. 9 shows in perspective the core made by bending the sheet into cylindrical form.

The case of the instrument is made of nonconducting material in two parts, A B,'screwed together, and holding between them the me-. tallic diaphragm G and its rubber washer (r. The front part, A, has the opening to which the ear is applied, and which I term the eartrumpet, lettered I), and it is made hollow to 7 receive the electromagnet D. The latter consists of a coil of insulated wire wound on the wooden spool or bobbin 0 in the usual way, the coil being electrically connected to line through the binding-posts d c, with which its two ends are respectively connected, as indicated by dotted lines 1 and 2, Fig. 2. Within the bobbin is the tubular soft-iron core E, which, as shown in Fig. 7, has the form of a cylindrical shell longitudinally slit on one side from end to end, as indicated at f. In Fig. l the inner end of the core, for the purpose of showing the parts more plainly, is represented as separated by quite a space from the diaphragm. In practice, however, it is set up considerably nearer to, and, in fact, just out of contact with, the diaphragm, in which adjusted position it is maintained by suitable means.

The results obtained by me from the forego- 9 5 ing-described construction and arrangement of parts have been already stated, and need not besrepeated here. 1

In the modification represented in Figs. 8 and 9 the metal sheet from which the core is made is preliminarily divided at its ends into a number of teeth or narrow strips,'g, by a series of slits, which extend from each end for about one-third the length of the sheet. The length of the teeth may be Varied; but I find in practice than when they are made of the length stated I obtain on the whole the best results. The sheet thus preliminarily formed is bent or rolled up into the form of a tube, as indicated in Fig. 9, and in this way a tubular core is produced having, as in the other instance, the longitudinal slitf, but having also, in addition, ends composed of strips g. This core is to be adjusted and used in the same manner as the core shown in theother figures. Having described my improvements and the best way now known to me of carrying the same into effect, what I claim therein as new and of my own invention is- 1. In a receiving-telephone, the combina' tion, with the diaphragm, of an electromagnet provided with a tubular longitudinally-split soft-iron core, substantially as and for the pur- 2 5 poses hereinbefore set forth.

2. In a receiving-telephone, the combination,with the diaphragm and the ear-trumpet, of an intermediate electro-magnet provided with atubular lol'lgitudinally-split soft-iron 0 core, which constitutes the communicating passage from the diaphragm to the ear-trumpet, substantially as hereinbefore set forth. I

3. The intermediate electro-magnet, having its coil electrically connected to line and pro- 5 vided with a tubular longitudinally-split softiron core, in combination with the diaphragm and the ear-trumpet, substantially as set forth.

4. The electro-magnet core E, consisting of a soft-iron cylindrical shell, having the longi= 4o tudinal slitfand divided ends 9, substantially as and for the purposes hereinbefore set forth.

In testimony whereofI have hereunto set my hand this 2d day of January, 1883.

JAMES A. MALONEY.

Witnesses:

EWELL A. DIcK, J. WALTER BLANDFQRD.

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