(No Model.) E. BERLINER, . No. 234,744. Patented Nov. 23, 1880.

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N. Peters, Photo-LTHOGRAPHER, WASHINGTN, c UNITED STATES PATENT OFFICE.

EMILE BERLINER, OF , MASSACHUSETTS. MCRO PHONE.

SPECIFICATION forming part of Letters Patent No. 284,744, dated November 23, 1880. Application filed March 31, 1880. (No model.) Patented in France January 8, 1880, in Belgium January 9, 1880, in Italy February 15, 1880. To all whom it may concern: the plate D and bears upon a piece of soft Be it known that I, EMILE BERLINER, of rubber on the diaphragm B, and by means of Boston, in the county of Suffolk and State of this screw the distance of the lower extremity Massachusetts, have invented a certain new of the plate D from the vibrating diaphragm and useful Improvement in or can be varied at will to any desired extent. Contact-, of which the following is The pressure of the end of the screw on the a specification, reference being had to the ac vibrating diaphragm also acts to damp the 55 companying drawings. vibrations of the diaphragm, and it is obvious This relates to that form of mi that this pressure admits of adjustment. O crophone or contact- described and E is a permanent magnet, which is attached claimed in Letters Patent of the United States, to the plate D, and may either be a bar-mag No. 225,790, March 23, 1880, in which one elec net, as shown, or a horseshoe-magnet. trode forms part of or is attached to a pendu G is the pendulous weight, having a carbon lous weight, which is kept from reaching its tip in contact with the carbon block P, and to point of rest by contact with the other elec this weight is fixed a plate, H., of soft iron, trode; and the improvement consists, first, in which forms the armature of the magnet E, the combination, with said pendulous weight, and is attracted and held to the magnet by its of an adjusting device whereby its angle of edge, so that it is able to oscillate freely on inclination to the other electrode and pressure the same from its point of suspension. upon the same can be varied at will; second, A copper wire, K, may be used for retain in the combination, with the vibrating surface ing this weight in position. 7 O of the microphone or contact-telephone, of an One pole of the battery is connected to the elastic arm to which one of the electrodes is plate D by the screw, which is insulated from attached, and an adjusting-screw the point of the diaphragm, and from thence the current 25 which is in contact with said surface and forms passes through the magnet to the carbon elec a damper to the same; third, in suspending the trode on the pendulous weight, and the other 75 pendulous weight from a magnet which holds pole of the battery is connected by the metal the said weight by attraction; and, fourth, in lic strip R to the carbon block P. electroplating the surface of the said magnet. By raising or depressing the free end of the In the accompanying drawings, Figure 1 is plate D by means of the screw M, the angle of a view, in perspective, of the back of a micro inclination of the weight G to the surface of phone or contact-telephone containing my im the electrode P and its pressure upon the same provements herein described, that part of the can be varied at will, so as affect the contact instrument which contains the induction-coil between the two electrodes as may be desired, 35 having been removed; and Fig. 2 is a vertical to secure the proper transmission of sounds. section through the same. It has been found that in microphones or In these several figures the same letters re contact-telephones containing a frictional con fer to the same parts. tact it is advisable to have the surfaces in con A is the block which supports the vibrating tact as smooth as possible. In this device this 4.O diaphragm B; and Pis a block of carbon, form result is attained at the contact of the arma ing one electrode of the circuit, which block ture H with the magnet E by electroplating is suitably attached to the center of the dia the surface of the magnet at that point. 9o phragm. By the use of an adjustable second armature D is an elastic plate of metal, which is fixed upon the magnet E, the force of attraction ex 45 at one extremity, by a screw or in any other erted upon the armature H can be varied as suitable manner, to the top of the block A and may be desired. 95 is free at its other end. This end is made an What I claim as my invention, and desire nular, so as to surround the carbon electrodeP. to secure by Letters Patent of the United A screw, M, passes through the lower end of States, is h ) 234,744 1. A microphone or contact - telephone in said pendulous weight, substantially as and which one electrode is held in position by be for the purpose set forth. ing suspended from or attached to a perma 4. In a microphone or contact-telephone, the ment magnet by attraction, substantially as combination of the diaphragm B, carbon block and for the purpose set forth. P, adjustable weight G, plate H, forming an 2. In a microphone or contact-telephone, the armature-magnet, E, elastic plate L, and ad combinatiou of a vibrating surface, a damper justing-screw M, substantially as and for the 25 consisting of an elastic arm provided with an purpose set forth. adjusting-screw, the extreme point of which 5. In a telephonic apparatus, a magnet form. bears against the said vibrating surface, and ing an electric contact and electroplated on two electrodes in variable contact with one its face in contact, substantially as and for another, which are situated between said screw the purpose set forth. point and the edge of said vibrating surface. In witness whereof I have hereunto set my 3. In a microphone or contact-telephone, the hand in presence of the subscribing witnesses. combination of a vibrating surface forming EMILE BERLINER, one electrode of an electric current, a pendu Witnesses: lous weight forming the opposite electrode, CHAS. E. BURLING-AME, and a device for changing the inclination of ALEX. L. HAYES.