US571399A - Telephone-transmitter - Google Patents

Description

(No Model.)

D. N. ROWAN. TELEPHONE TRANSMITTER.

Patented Nov. 17, 1896.

. UNITED STATES PATENT OFFICE.

DAVID NOBLE ROIVAN, OF IRVINGTON, NE\V YORK.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 571,399, dated November 1'7, 1896.

' Application fil d December 10,1895. Serial No. 571,701. (No model.)

To all whom it may concern:

Be it known that I, DAVID NOBLE ROWAN, a citizen of the United States, residing at Irvington, county of Westchestcr, State of New York, have invented a certain new and useful Improvement in Telephone-Transmitters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephone-transmitters with two electrodes, between which granulated or globular particles of conducting material is used to vary the electrical resistance, and adapted to short or long distance service.

I prefer to construct my transmitters by having a solid electrode in the rcar,with nonconducting shelves attached to its face,witl1 granular or globular conducting material suspended on the shelves between the electrodes.

My invention consists in the combination of fiexible-non-conducting shelves with sufficient granular or globular conducting material suspended on the shelves between the electrodes to produce the required varying resistance, first, in combination with a single diaphragm in contact with the shelves and the granular or globular conducting material regulated by a pressure device; second, in combination with a movable inner diaphragm in contact with the shelves and the granular or globular conducting material,with a fixed outer diaphragm, with a space between the diaphraglns, with a pressure device, for in stance, a screw and nut, for regulating the pressure of the inner diaphragm against the shelves and the granular or globular conducting material. These shelves may be madein various ways, but I have produced the best results with and prefer to use shelves, horizontal or circular, made of thin strips of mica or celluloid, as shown in my illustrations, which I can securely attach at any required angle to the face of the rear electrode. I prefer the use of mica forthe shelves because it is practically indestructible, not affected by the weather, and does not deteriorate by age, is not attacked by parasites, and possesses in the highest degree the quality of resiliency and responds to the vibrations of the diaphragm, and the granules are by each continuously moved by or agitated by the same process. It is impossible for the granules to pack on the shelves or against the electrodes.

I11 adjusting the workings of the transmitter when a single diaphragm is used I place the front electrode so that it presses against the projecting edges of theshelves, which keeps the granules from overflowing from one shelf to another or into the case and brings the granules in contact with the front electrode above the line of shelves. The ends of the shelves constructed to be horizontal when used are closed at each end by non-conducting material, and the circular shelves are continuous. Each shelf securely holdsthe granules therein placed. .Any adj ustment needed to produce the more perfect results can be made by moving the front electrode forward, pressing the flexible shelves and the granules, or drawingitback to relieve the pressure when the rear electrode is stationary, as, for instance, by a screw and nut, or by movingthe rear electrode to which the shelves are attached up to or back from the front electrode when the diaphragm is stationary. Another and preferable mode 'of constructing the front electrode is to cover the shelves attached to the rear electrode by a carbon or metal inner movable diaphragm or disk which sets in a case of non-conducting material which surrounds the back electrode and supports the inner diaphragm, having an outer fixed diaphragm, which may be of any suitable material, metal preferred, leaving a space between the outer diaphragm and the inner diaphragm or disk. The outer diaphragm is sustained by its edges, but free to vibrate, with a fixed adjustable nut attached to its center with a screw passing through the fixed nut and projecting through this diaphragm. The screw is smooth-pointed and worked from the front of the transmitter by a screw-driver orotherwise, so that the point of the screw touches the face of the inner diaphragm or disk, the result being that each vibration of the outer diaphragm instantaneously presses the point of the screw against the inner diaphragm or disk, which IOO vibrates it simultaneously with the outer diaphragm, the inner diaphragm or disk per forming the same functions as if directly acted upon by the voice, but more effectively. This screw also acts as an adjuster.

The accompanying drawings illustrate my invention. p v

Figure 1 is a side elevation of a telephonetransmitter embodying my invention when set up perpendicularly for commercial use. Fig. 2 is a sectional View of the rear electrode, showing myinvention when the shelves are placed horizontally with a single 'dia Fig. 3 is a sectional view of the phragm. same thing, showing my invention when the shelves are placed circular. Figs. 4 and 5 are views of the faces of Figs. 2 and 3, illustrating the two methods of arranging the shelves. of Fig. 1, showing my invention when I use horizontal shelves and asingle diaphragm. Fig. 7 is the same showing the circular shelves. Fig. 8 shows the same when I use an inner and outer diaphragm and shows the adj usting device. Fig. '9 is the same as Fig. 2-, showing its construction when I use a noncon'ductin'g diaphragm. 4

I will describe my'in'yention as illustrated.

"0. and a are the two parts of the ome case, which ma be of metal, glass, wood, hard rub her, or other composition. I prefer it made of non-conducting material, because if made of metalit requires a lining of non-conducting material. a p I 'Z; is the usual mouthpiece into which the user speaks.

c is the outer diaphragm, and c is the inne'r "diaphragm. Either'or both can bemade of metal or hard carbon or other suitable m-aterial. Y

dis the metal ring or plate to which the diaphragm c is attached when only one diaphragm is used, and when the outer dia'*-.

phragm c is not used forms the front electro'd'e from which contact is taken.

I Cl is the front electrode when the outer diaph'ragm cis used, and contact is taken from the adjusting-nut on the outer diaphragm c.

'e is the rear electrode, which can be made I prefer the latter, or it can be hard carbon electrotyped with metal to strengthen it,'which is fastened to a of metal or hard carbon.

by means of a screw or screws or clamp.

.f are the non-conducting vibrating shelves,

which I make of mica or any other suitable non-"conductin g material and firmly attach to willmove flexibly and vibrate.

g is a screw which passes through the center of the electrode 6 and case a, holding them together, and from which contact can 1 be taken to h, which is the contact-post of the rear electrode, and maybe used as an adjusting-screw to move the rear electrode.

1' is the contact-post of the front electrode (Z or cl,connected by means of a wire running through case a.

Fig. 6 is a vertical central s ction,

j is the granulated carbon between the elec trodes.

76 is the adj listing-screw to move the inner diaphragm 0 when two diaphragms are used.

Z is the insulation-band inclosing rear electrode e and forming the end of the horizontal shelves.

Z is the same when it covers 6 and insulates it from the metal ring 012.

m is a wide metal ring which I use in connection with and when I use a non-conduct ing diaphragm, such as wood or mica, with the horizontal shelves, which passes sufficiently over the rear electrode, separated therefrom by insulating material Z, such as mica or its equivalent, so that it will allow the diaphragm which is attached to its top or front end to come in contact with the shelves, and at the same time the inside of the metal ring forms the end of the shelves coming in contact with the granulated car'- bonformiig the front electrode. 7 v

' Although I show the two forms of flexible shelves which I prefer, the material and 001m positions may be varied to ope-rate in a similar manner for the same pujrpose in squares, diamonds, octagonal, and other shapes and at different angles. I have worked the shelves when placed from ten degrees to a right angleto the face of the rear electrode, but I prefer when I use circular shelves to place them at from twenty to thirty degrees to the face of the rear electrode, and when I use hori'zontalshelves to place them-at from fortyfive to fifty degrees to the face of the rear electrode. V 7

Having described the preferable forms of my deviceand different modifications thereof, I do not limit myself to the particular mechanism shown or described, because I found that modified {and different forms of shelves, while not producing as good results as the two forms which I prefer and have adopted for commercial purposes, were much better and cheaper than most of the transmitters now in use. V

The transmitter which I have described is adapted to short or long service, according to the amount of electrical force used in connection with it, and they are uniform in quality of transmission.

Having described my invention, I claim and desire to secure by Letters Patent-- 1-. In a telephone-transmitter, the combination of flexible, non-conducting shelves,

I I w electrodes, and granular conducting material the face of the rear electrode, so that they suspended on the shelves between the electrodes as described.

2. In a telephone-transmitter, the combination of flexible non-conducting shelves, granular conducting material thereon suspended on the shelves between electrodes, an inner diaphragm in contact with the shelves and the granular con ductin g material, a fixed outer diaphragm with a space between the diaphragms and a mechanical connection between the diaphragms, as described.

IIO

rial thereon suspended between the electrodes, an inner diaphragm in contact with the shelves andthe granular conducting material, a fixed outer diaphragm, with a space 15 between the diaphragms and a screw and nut for regulating the pressure of the inner diaphragm against the shelves and the granular conducting material thereon, as described.

In witness whereof I have hereunto set my 20 hand and seal this 30th day of November,

D. NOBLE ROWAN. [14. s.] Witnesses:

T. W. MOORE, WEBSTER GILLETTE.

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