US321323A - Henry s - Google Patents

Description

(No Model.)

H. S. THORNBBRRY.

TELEPHONE TRANSMITTER.

No. 321,328. Patented June 30,1885.

UNITED STnTns PATENT @rrrcn.

HENRY S. THOENBERRY, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE AMERICAX BELL TELEPHONE COMPANY, OF SAME PLACE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 321,323, dated June 30, 1885. Application filed July 5, 1884. (No modelJ To all whom it may concern:

Be it known that I, HENRY S. THORNBERRY, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain improvements in TelephoneTransmitters, of

which the following is a specification.

The object .of my invention is to improve the construction and to render more popular and effective that form of batterytransmitter in which particles of conducting material, in

a loose or free state, form the current-regulating medium.

The transmitter described in United States Letters Patent granted to Henry Hunnings,

1 No. 250,250, November 29, 1881, is of this class. In the practical operation of that transmitter ithas been found desirable in attaining the best results to hold the transmitter at a certain angle between the horizontal and vertical, and it has also been found that after such transmitter has been in frequent use the particles become moist and sticky. This is due, it is believed, to the moisture from the i breath of the operator, which reaches the par- 2 5 ticles around the edges of the diaphragm, the edges being, as customary, left freethat is to say, not permanently fastened to its seat, as by solder, but merely held against the same by greater or less pressure. In the ordinary o Hunnings transmitter, such as imported into this country, a circular chamber is made in a block of insulating material which contains the loose conducting particles. Above the latter is a very thin platinum diaphragm, and upon this a brass plate having a number of small holes. lVhen the sievelike brass plate is omitted, which is an improvement, and only the thin platinum diaphragm used, the rotating rubbing movement of the cap 0 which holds it down frequently wrinkles the edge of the disk, leaving-a passage sufficient for the moisture to reach the carbon particles. Sometimes a few of these particles will find their way between the disk and its seat and 5 prevent the latter from lying perfectly fiat. Thus, in one way or another, it will happen that if moisture is permitted to reach the disk it will find its way behind it. To obviate these diiiiculties I rigidly fix the chamber con lining the variable resistance of my transmitter at that angle from the horizontal in practice found most desirable, which angle might be slightly varied, and I place before the diaphragm a curved metal trumpet or mouthpiece, against the sides of which any moisture will strike and be precipitated,

My invention further consists in placing the vibrating diaphragm under the mass of conducting medium, or, inother words, placing the particles of conducting material on the diaphragm, where they are normally held by gravity and rendered more sensitive to soundvibrations than was formerly the case. I furtherimprove the effectiveness of the instrument by using a damper of a substance such as a thin sheet of rubber, cork, or animal tissue placed outside of the platinunrfoil diaphragm commonly in use.

My invention also consists in rendering the chamber in which the conductingparticles are confined adjustable, and in certain details of construction, to be described.

In the accompanying drawings, Figure 1 shows my transmitter complete. Fig. 2 shows a section of the trumpet, containing-chamber, and operative parts. Fig. 3 shows a modification. Fig. 4 shows details of construction.

T is a metal trumpet or mouth-piece curved and arranged, substantially as shown, so that the particles of moisture conveyed thereto from the month in speaking (such particles moving in straight lines) will strike the further side of the tube and be precipitated or retained and the conducting material will not be affected. Metal is the preferred material for the trumpet because, being a. better conductor of heat than wood, rubber, and other substances, the moisture will readily condense upon it. The upper end of Tis screw-threaded to receive a screw-thread, c, on the contain- 9 ing-chainber 0, preferably formed from some non-conducting substance, as vulcanized rubher.

0 is a collar firmly fixed to chamber 0 and screw-threaded to receive a metal ring, r.

S is a screw-plunger, the head of which enters the chamber N, wherein are placed particles of finely-divided conducting material a, as granulated retortcarbon. The enlarged end of S may be projected more or less into 109 chamber N to regulate the size of said chamber. Upon plunger S is fixed a set-screw, s,

to which one end of the battery-circuit is connected. The object of this construction is to enable the size of the containing-chamber for the finely-divided material to be changed at will. In transmitters of this class the best results .are obtained by filling the chamber about two-thirds full. Sometimes, however, a high normal resistance is required, and consequently a larger quantity of carbon or other particles are needed in the chamber. By turning the set-screw s in the proper direction the plunger S can be withdrawn, so as to enlarge the size of the chamber to admit the increased amount of conducting particles.

Over the aperture in ring ris placed a platinum diaphragm, p, andbetweenthis platinum diaphragm and the aperture of ring 1", I place a damper consisting of a thin sheet of animal tissue of a flexible nature, as d,- or it may bea thin sheet of rubber or cork,which I affiX to the platinum diaphragm by a drop of some adhesive substance, as sealing-wax, placed at or near the center thereof;

To avoid the possibility of injuring or changing the form of the damper, I place athin washer, w, Fig. at, outside thereof, against which the surface of ring rwillturn in screwing it on.

Instead of fixing the damper d to the diaphragm p by some adhesive substance, the damper and diaphragm may be held in contact by an adjustable spring, as a.

Around the inner orifice of the trumpetT a shoulder, as y, is turned up, against which the metal ring r presses when in position. The second end of the battery'circuit is connected to trumpet T, as at t, circuit passing via elements t T y r p, conductingparticles n, S, and s. This circuit may be the main circuit and battery or a local circuit and induction-coil, as is well-known. It will be noticed that at all points this circuit is of sufficient conductivity to avoid heating by any ordinary battery.

The apparatus so constructed is placed in position substantially as shownin Fig. 1. The case B is formed and intended-to be placed firmly in position, as upon a wall, and the location of trumpet T is such that the plane of either or both walls of the chamber N will be at an angle from the horizontal, preferably of from twenty to thirty degrees, this being found in practice the most advantageous position, since in this position it is believed that the conducting particles are not so likely to pack or solidify.

The operation of my transmitteris similar to others of its class.

What I claim, and desire tosecure by Let ters Patent, is-

1. A telephonic transmitter comprising a mass of finelydivided conducting particles confined and resting upon a diaphragm located at an angle between a horizontal and perpendicular.

2. In a telephone-transmitter, an adjustable chamber containingparticles of finely-divided conducting material resting upon a flexible diaphragm fixed at an angle between a horizontal and perpendicular.

3. In a telephonic transmitter wherein the means forvaryingthe circuit consists of a mass of finely-divided conducting particles, a chamber for containing such particles, and having means for regulating the size of said chamber to admit of a greater or less quantity of such particles.

4. The combination, in a telephone-transmitter, of a mass of finely-divided conducting material resting by gravity upon a metallic:

diaphragm, a damper consisting of a disk of animal tissue, cork, rubber, or similar material cemented to thediaphragm at or near its center, and clamped thereto at its periphery by a perforated cap or ring, with an intervening ring or washer to prevent displacement of the damper, substantially as described.

5. An electric telephonic transmitter comprising a mass of finely-divided conducting particles confined and resting upon a diaphragm located at an angle between a horizontal and perpendicular, and a damper consisting of a thin sheet of animal tissue, rubber, cork, or other like material.

6. The combination, in a telephone-transmitter, of an inclosin g chamber containing finely-divided conducting material resting upon a metallic diaphragm, with a damper consisting of a disk of animal tissue, cork, or rubber cemented to the diaphragm at or near the center thereof.

7. In a telephonic transmitter, the combination of a chamber for containing the currentvarying medium, means for varying the size of said chamber, a flexible metallic diaphragm upon which the said medium normally rests by gravity, a mouth-piece, and an inclosing-case, the whole arranged to permanently retain the diaphragm at an angle between a horizontal and perpendicular, substantially as described.

8. In a telephonic transmitter, the combination of the chamber 0, adjustable plunger S, conducting particles n, diaphragm p, damper (1, and trumpet or mouth-piece T.

In testimony whereof I have signed my name to this specification,in the presence of two sub: scribing witnesses, this 28th day of June, 1884.

H. S. THORNBERRY.

\Vitnesses:

WM. 13. VANSIZE, GEO. VVILLIs PIERoE.

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