US1551723A - Transmitter - Google Patents

Description

.Sept. 1, 1925. 1,551,723

F. H. N. WOHLERS TRANSMITTER Filed April 14. 1921 IIIIIIIIIII A TTORNEYJ.

Patented Sept. 1, 1925.

UNITED STATES 1,551,723 PATENT OFFICE.

FRIEDRICH H. N. WOHLERS, OF JAMAICA, NEW YORK, ASSIGNOR TO DICTOGRAPH PRODUCTS CORPORATION, A CORPORATION OF VIRGINIA.

TRANSMITTER.

Application filed April 14, 1921. Serial 110. 461,283.

To all whom it may concern:

Be it known that I, FRIEDRICH H. N. WOHLERS, a citizen of the United States, residing at Jamaica, in the county of Queens and State of New York, have invented certain new and useful Improvements in Transmitters, of which the following is a full, clear, and exact description.

In carbon ball transmitters utilizing a plurality of ets of a conducting element and engaged by a diaphragm, such as disclosed for example in U. S. Patent No. 844,635, it has been found that if the transmitter is subjected to jars or shocks such as are occasioned by dropping of the transmitter, the diaphragm often springs or flexes away from the conducting element or pockets sufliciently to allow the small balls to escape entirely from the pockets of the elements or to become wedged between the diaphragm and the 01'- tion of the conducting element surroun ing the pockets, with the result that the diaphragm either cannot vibrate at all or the absence of the balls from the pockets prevents or limits the passage of current between the diaphragm and the conducting element.

The object of my invention is to provide a carbon ball transmitter in which it is impossible for the balls to get out of place or lost, to generally improve and sim lify the construction of transmitters of t is type,

eleminate difficult and expensive machine work in their manufacture, and improve the attachment of the face cap to. the casing. Other objects and advantages will be ap parent from the following description and the novel features of my invention will be particularly pointed out in claims.

In carrying my invention into practice I support an abutment adjacent the face of the diaphragm and opposite the conducting element, but spaced therefrom sufiiciently to permit of the normal vibration of the diaphragm and acting to limit excessive movement of he diaphragm such as would release the b lls from the cavities of the conducting element. The same abutment is also preferably utilized as the support for the face cap of the instrument. The invention also com rises certain details and arrangements w ich will be hereinafter more particularly described in connection with the illustrated embodiment of my invention.

very small carbon balls in pock- In the drawings:

Fig. 1 is a front elevation of a transmitter constructed in accordance with my in- Vention;

Fig. 2 is a section of the same taken substantially along the line 2-2 of Fig. 1;

Fig. 3 is a plan of a detail of the transmitter, and

Fig. 4 is a plan of the cup carrying the conductin elements.

A suita le handle 1 is provided at one end with connections 2 fora twin cable 3 entering the same and by means of which the instrument is connected to any suitable external circuit. The opposite end of the handle terminates in a casing 4 having an open face in which is disposed the trans mitter mechanism proper. A cup 5 is removably disposed within the bottom of the casing 4 and carries a pair of carbon blocks 6 which are secured thereto by screws 7. Insulating pads 8 are interposed between the carbon blocks 6 and the bottom of the cup for insulating the blocks therefrom and suitable insulation 9 is interposed between the two blocks. A contact plate 10 is interposed between each block and its insulating pad and has an enlarged aperture 11" for,the passage of the securing screw 7.

insulating sleeve 12 surrounds each screw 7 so as to insulate it from the contact plate .10 and carbon block, the head of the screw bein countersunk below the face of the carbon lock. Each block is provided with a plurality of cavities or depressions 13 in its outer face, in which are disposed a plurality of small carbon balls 14. A diaphragm 15 of conducting material is clamped across the up er face of the cup at the periphery thereof by means of a suitable disk like element or member 16 which is threaded into the interior of the open end of casing 4, suitable gaskets 17 being interposed between the diaphragm and both the element 16 and the cup 5 so as to insulate the diaphragm from the casing. The depth of the on 5 is such as to cause the diaphragm to be isposed in a slightly spaced relation to the outer faces of the carbon blocks and retain the balls 14 within the cavities and at the same time be free to vibrate slightly without contacting with the carbon blocks. The disk-like element 16 has an o ening 18 in its central portion which is bri ged by arms 19 carrying at their junction 9. boss 20. The

necessary for its normal vibration and prevent movement to an extent sufficient to release the balls from the cavities. The boss is provided with a threaded aperture 21 which receives a threaded stem 22 of a cap plate 23 which closes the outer face of the casing 4. The cap plate is provided with mitter should be accidentally -ishes or suitable openings 24 for permitting entrance of the sound waves to the casing in order to actuate the diaphragm and through it vary the resistance of the circuit. The carbon blocks are connected through their contact plates 10 and wires 11 with the connections 2 in the opposite end of the handle.

The external circuit is connected to the instrument by cable/3, the current passing through one .of the wires 11 to one of the contact plates 10, the carbon block 6 carried thereby, the carbon balls in the pockets of that block, a diaphragm in contact therewith, through the diaphragm, then through the carbon balls of the other carbon block which are in contact therewith, the other carbon block, its contact plate 10 and the corresponding wire 11 back to the cable 3. As the sound waves enter the apertures 24 of the casing they impinge upon the diaphragm and set the latter in vibration. The diaphragm in vibrating displaces the .carbon balls in their pockets and by this displacement varies the resistance through the same and causes a fluctuation in the. current passing through the circuit described. This variation in the current in the circuit is utilized at another point in the circuit for the reproduction of the sound waves in a manner well known in the art. If the transdropped or subfected to severe shocks, the diaphragm Wll be prevented from moving away from the carbon blocks sufliciently to allow the balls to esca e from the pockets, owing to the contact 0 the diaphragm with the abutment 20 upon an excessive flexure of the diaphragm. The boss also acts as a support for the stem projecting from the cap which eliminates the necessity of threadmg the cap to fit the casing and enables the cap to stamped from sheet metal and the stem which can be inexpensively produced in automatic I machines can be attached thereto by riveting.

The ca can be produced in various fineslgns to match furniture or other fittings a d attached to a standard transmltter so as to eliminate the necessityof producing the entire transmitter in various particular finishes thus considerably lessenmeg-1 the cost and stock which should be carn It will be obvious that various details and changes in the construction herein described and illustrated may be made by those skilled in the art within the principle and scope of the invention.

I claim: 7

1. In a telephone transmitter, a block of conducting material having cavities in a face thereof, a diaphragm 1n juxtaposition to but slightly spaced from said block and cavities, a plurality of small balls confined in each of said cavities by the diaphragm, and an abutment adjacent to but slightly spaced from the face of the diaphragm opposite to the block whereby movement of the diaphragm away from the block sufficiently to release the balls from the cavities will be prevented without restricting normal vibratory movement of the diaphragm.

2. In a telephone transmitter, a conducting element having a cavity in a face thereof, a diaphragm supported in juxtaposition to but slightly spaced from the said face of the element, a plurality of small balls confined within the cavity by the diaphragm, and means permitting normal vibratory movement of the diaphragm but preventing an amplitude of movement of the same sufficient to release the balls from the cavity.

3.111 a telephone transmitter, a casing, a conducting element having a. cavity in a face thereof carried within the casing, a diaphragm supported in juxtaposition to but slightly spaced from the said face of the element, a plurality of small balls confined within the cavity by the diaphragm, and a membercarried by the casing for clamping the diaphragm and element in osition in the casing and having a portion 1n juxtaposition to but slightly spaced from the central portion of the diaphragm opposite the conducting element for preventing an amplitude of movement of the diaphragm sufficient to release the balls from the cavity.

4. In a telephone transmitter, a. casing, a conducting elementv having a cavity in a face thereof carried within the casing, a dia phragm supported in juxtaposition to but slightly spaced from the said face of the element, a plurality of small balls confined Within the cavity by the diaphragm, a member carried by the casing for clamping the diaphragm and element in osition in the casin and having a portion in juxtapd sition to ut slightly spaced from the central portion of the diaphragm opposite the conducting element for preventing an amplitude of movement of the diaphragm suf-- ficient to release the balls from the cavity, and a perforated cap for closing the casing carried by the member.

5. In a telephone transmitter, a casing, a conducting element having a cavity in a face thereof carried withln the casing, 11.

diaphragm supported in juxtaposition and member having apertures permitting passage of sound waves to the diaphragm from the exterior of the casing.

6. In a telephone transmitter, a casing having an open face, a cup removably disposed in the bottom of the casing and'open: ing toward the open face of the casing, a

' conducting element carried within the cup.

and-having a cavity in its outer face, a diaphragm closing the-open face of the cup and passing in uxtaposition to but spaced slightly from the said outer face of the conducting element, a plurality of small balls confined within the cavity by the diaphragm,

and a member adjustably engaging with the casing to' clamp the diaphragm against the edge of the cup and both againstvthe rear wall of the casing.

7. In a telephone transmitter, a casing having an open face, a-cup removablydis posed in the bottom of the casing and opening toward the open face of the casing, -.a conducting element carried within the cup and. having a cavity in its outer face, a diaphragm closing the open face of the cup and passing injux-taposition to but spaced slightly from the said outer face of the conducting element, a plurality of small balls x confined within the cavity by the diaphragm, and a member adjustably engaging with the casing to clamp the diaphragm .balls from the cavity.

against the edge of the cup and both against vthe rear wall, of the casing, said member having an opening for the passage of sound waves tothe diaphragm and also having a portion in juxtaposition to but slightly s aced from the central portion of the diap ragm for preventing movement of the diaphragm away from the conducting. element to an extent suflicient (to release the 8. In a telephone transmitte a casing having an open face,. a cup removably disosed in the bottom of the casing and openmg toward the open face of the casing, a conducting element carried within the cup and having a cavity in its outerface, a diaphragm closing the open face of the cup and passing in juxtaposition to but spaced slightly from the said outer face of the conducting element, a plurality of small balls confined within the cavity by the diaphragm, and a member adjustably engaging with the casing to clamp the diaphragm against the edge of the cup and both a 'ainst the rear -wall of the casing, and a per orated cap detachably carried by the member for closing the casing. r

9. In a telephone transmitter, a casing having an open'face, a on removably disposed in the bottom of the casing and open: ing toward the open face of the casing, a conducting element carried within the cup and having a cavity in its outer face, a dia hragm closing the open face of the cup an passing in juxtaposition to but spaced slightly from the said outer face of the conducting element, a plurality of small balls with the casing to clamp the diaphragm against the edge of the cup and both against the rear wall of the casing, said ,member having an opening for the passage of sound waves to the diaphragmand also having a portion in juxtaposition to but slightly s aced from-the central portion of the diap ragm for preventing movement of the diaphragm away from the conducting ele-' ment to an extent suflicientto release the,

balls from the cavity, and a perforated cap detachably carried by the member for closing the open face of the casin 10. In a telephone transmitter, a casing having anopen face,'a cup removably disposed in the bottom of the casing and openmg toward the open face of the casing, a conducting element carriedw-ithin the cup and having a cavity in its outer face, a diaphragm closing the open face of the cup and passing in juxtaposition to but, s aced slightly from the said outer face '0 the conducting element, a plurality of small balls confined within the cavitv hv the diaphragm, a member-adjustably engaging with thecasing to clamp the diaphragm against the edge of the cup and both against the rear Wall of the casing, said member carryconfined within the cavity by the dia 'phragm, a member adjustably engaging ing a boss at its central portion. in juxtaposition to but slightly-spaced from the central portion of the diaphragm for preventing movement of the diaphragm away from the conducting element to an extent sufficient to release the balls from,the-cavity, a cap for closing the casing and havingaa threaded stem projectingcentrally therefrom, said boss having a threadedapertureforflreceivingsaidthreaded stem thereby and detachably securing the cap to the casing, said cap and member havingopen portions permitting the passage of sound waves-from the exterior of the casingto the diaphragm.

In witness whereof I hereunto subscribe" my. signature.

FRIEDRIOH'I-I. N; .Wo'HmaRs.

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