US417009A - Joseph c - Google Patents

Description

(No Model.)

J. O. EIGHME'YER, TELEPHONE TRANS MITTE'R.

Patented DedQlO, 1889.

n. Prsns. Phokoiilbogmplmr. Wnhington. n c.

" UNITED STATES PATENT." Oriucn.

JOSEPH (J. EICHMEYER, OF UTICA, NEW YORK, ASSIGNOR OF NINE 'IEN'lI-IS TO FRANK J. CALLANEN, JOSEPH R. SYVAN, AND AUGUSTUS ll. PALMER,

ALL OF SAME PLACE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 417,009, dated December 10, 1889.

Application filed March 26, 1886. Renewed November 22, 1886. Again renewed July 27, 1887. Serial No. 245, modem T aZZ whom it may concern:

Be it known that I, JOSEPH. C. EICHMEYER, of Utica, in the county of Oneida and State of New York, have invented certain new and useful Improvements in Telephone -Transmitters; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this IO specification, and to the letters of reference marked thereon.

My invention relates to improvements in that class of telephone-transmitters in which the variations in the resistance of the circuit I 5 are produced by varying the pressure upon 'and contact-between fine particles of carbon placed in a suitable receptacle by vibrations communicated to them through the medium of a suitable diaphragm or other medium vibrated in accordance with sound waves;

and it consists in a certain improved construction, which I will now proceed to'describe.

In the drawings, Figure 1 is a longitudinal sectional View of a transmitter constructed in accordance with my invention. Fig. 2 is a top plan view of the same with the top of the casing removed. Fig. 3 is a view of a detail.

A represents the back piece or back, to which the box or chamber containing the operating parts of the instrument is fastened, adapted to be secured to the wall or other convenient support; and B represents the bottom board of the receptacle, secured to the back A, as shown, and having nearits center a large circular opening.

0 represents a plate, preferably of metal, adapted to be secured to the under side of the board B by means of a number of screws a, projecting downward through said board and plate and having nuts I) mounted on their lower ends for drawing the plate 0 up against the under side of board B. Near the center of the upper side of this plate, and preferably formed integral therewith, is a circular flange or ring D, closely fitting the opening in the board and extending up through about flush with its upper surface. On the inside of this ring is a slight annular shoulder or offset (Z, on which the diaphragm rest-s. The plate 0 is further provided near its center with an annular perforation 0, around which is secured the smaller end of the trumpet-shaped mouthpiece F, flaring outwardly, with the opening toward the front of the instrument.

G represents a conical button or plug, preferably of hard rubber, (though any other similar material will answer,) secured in the smaller end of the trumpet F with its point toward the opening and its upper side fiush with the inside of the plate 0, and provided on its periphery with aseries of small grooves ff, all as shown in Fig. 3.

II is the diaphragm, consisting, preferably, of a sheet of hard carbon resting upon the annular shoulder of the ring D over the opening in the plate 0, and adapted to be held down in place by means of a ring-follower H, of hard rubber or similar non-conducting material, fitting within the ring D and resting upon it. The upper end of this ring H is beveled toward the center, as shown, and upon the upper side of the ring D are three or more tapped lugs or proj ections e,in which are mounted pointed screws 6, the ends of the latter being in engagement with the incline or bevel on the ring 11, so that as they are screwedin they'will ride up the incline and press the ring and diaphragm firmly down in position.

Upon the upper side of the board 13 is secured a large metal plate I, having the circular opening, as shown, for accommodation of the rings D and H, and upon this plate at equal distances apart are secured in any suitable manner three supports or posts J, constructed preferably of metal, though any other material may be employed, if desired, having their upper ends bifurcated, and carbon pencils K are pivoted between the arms thus formed upon pins 7e, passed transversely through them, the pins It being free to move in their bearings in the arms. The longer end of each of the carbon rods or pencils extends down to near the center of the diaphragm, the endsbein g preferablymade poly onal, as shown, and, if desired, the faces thus I ble fastenin gs to the board B.

formed smoothed or polished. -A thin layer of. powdered carbon being placed upon the diaphragm, the ends of the carbon pencils are brought down and the remainder of the cup formed by the ring H and the diaphragm filled nearly to the top with powdered carbon, as shown in Fig. 1, so that the ends of the pencils will be embedded in it.

The posts J, that bear the carbon pencils, may be of metal and in electrical contact with the plate I, or of any other material, and, if non-conductors, connection may be made between the plate and pencils by means of a wire, or abetter connection may be made between the pencil and post by a wire ,2, as shown. The plateI is secured by any suita- A small screw m passes down through the board 13 and into the plate C, and a wire 00, connected to this screw at its upper end, forms the connection between the diaphragm and the battery. The connection between the plate I, on which the pencils are mounted, and the primary of the induction-coil is formed by the wire 1 as shown.

The operation of the instrument from the above description will now be apparent. The sound entering the trumpet F will pass upward and will split, so to speak, upon the end of the button G and pass through the corrugations on the periphery and be delivered into the chamber below the diaphragm and evenly distributed upon the surface of the latter in the form of a circle, thereby rendering it less liable to be convulsed by harsh or loud discordant sounds. By't'he vibrations of the diaphragm caused by the 'speakers voice the contact between the pulverized carbon on the diaphragm and the carbon sticks and the resistance of the circuit will be correspondingly varied, and the impulses transmitted over the line in the ordinary manner through the induction-coil and ground-connection.

It will be observed that the contact between the electrodes in my improved instrument is preserved at all times by an even and regular pressure caused by the weight of the carbon sticks, and by the vibrations of the diaphragm the pulverized carbon will be fed down between the pencils, which action, combined with the weight of carbons, will determine the ultimate position of the latter with respect to the diaphragm, and therefore the instrument will not be readily thrown out of adjustment, but is ready at all times to transmit the loudest or faintest sounds wit-h accuracy.

The faces of the pencils may be smooth and polished, if desired, so as to render the contact better.

It is obvious that various modifications can be devised without departing from the spirit of my invention, and therefore I do not desire to be limited to the exact construction shown and described herein. For instance, a metal diaphragm might be employed having its upper surface coated with carbon or even without the coating, or instead of the sticks of carbon metal rods might be used,

the main object being to provide a trans-- mitt-ing-instrument in which the contact between the electrodes, one of which is pulverized carbon or equivalent substance, is secured by means of gravity alone.

I claim as my invention.

1. In a telephone-transmitter, the combination, with the diaphragm and the-mass of finely divided semi conducting material mounted thereon,forming one terminal of an electric circuit, of one or more gravitating electrodes forming the other terminal, pivoted at their upper ends, and having their lower ends embedded in said semi-conducting material, being held in contact therewith by gravity alone, substantially as described.

2. In a telephone-transmitter, the combination, with the carbon diaphragm and the pulverized carbon thereon, forming one terminal of an electric circuit, of the pivoted gravitating carbon pencils having one end embedded in said pulverized carbon forming the other terminal of the circuit, substantially as described.

3. The combination, with the plate, the ring having the lugs and screws mounted thereon, the diaphragm, and the ring-follower having the beveled upper side, substantially as described.

4. The combination, with the plate, the ring having the lugs and pivoted screws therein, and the offset d, forming a seat for the diaphragm, and the diaphragm, of the ringfollower mounted on the diaphragm, having the beveled upper side with which the screws co-operate to clamp the latter securely in position, substantially as described.

JOSEPH C. EICHMEYER.

Witnesses:

J. G. GIBSON, JAMES W. WATTs.

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