US1518744A - Radiophone amplifier - Google Patents

Description

Dec. 9, 1924- 1 3,144.

A. N. MARTIN v RADIOPHONE AMPLIFIER Filed April 21 1923 INVENTOR V many other distinctly disturbing and distor- Patented Dec. 9, 1924..

UNITED STATES Annual) n. .ZMARTIN, on NEW 1203?, NEW you.

BADIOPHONE AMPLIFIER.

Application filed April 21, 1923. Serial No. 633,649.

To all whom itmay concern:

Be it known that I, ALFRED N. MARTIN, a citizen of the United States, residing at New Dorp, Staten Island, in the county of Richmondand State of NewiYork, have in vented certain new and useful-Improvements in Radiophone Amplifiers, of which the following is a specification.

This invention relates tosound conduct ing and amplifying means of the receiving type pertinent to radio operations,

Havmg 1n mind numerous objections to v a p y g 'q p t deVlceS 110W Fig. 4 is a detail view of one of my imcommonly in use, suchas tinny, nasal, and

tive kinds of sounds, not traceable or chargeable to the original broadcasting of musical or-other sounds, in the development of this present equipment I contemplate a number of objectsamong which are the magnification or amplification of the transmitted sounds, whereby, I obtain not --0I1ly unusual volume but particularly pleasing elfects, free or practically free from annoying or undeing apparatus peculiarly constructed for the '.purpose of producing sweet or favorable sirable tonal eifects; to provide an amplifytonequalities and which moreover are subject to very delicate'or precise adjustment for thepurpose desired; to provide a system or apparatus for amplification of soundsat the receiving station which includes means for magnifying the tones-in a .variable adjustable manner that is equivalent in this amplifying construction to a rheostatand socket for tuning a vacum bulbin the now commonly used receiving set, that is, it not alone magnifies the sound, but by the balance or adjustment of the sound magnifier or microphone, it can be made to do duty in modifying and increasing the volume or intensity in the amplifying system in a peculiarly novel manner, and also another object of my-invention is to obtain by a new and peculiar combination of parts,"a result heretofore unknown, with respect especially to the volume and quality of the tonal effect.

With the foregoing and other, objects in view the invention consists in the arrangement and combination of'parts hereinafter described and claimed, and while my invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to theaccompanying drawings, inwhich like proved microphones or tone magnifiers.

Referring now more specifically to the drawings, but at the same time specifically asserting my intention not to be unnecessarily limited to the specific mechanism illustrated, I show a resonant body '10 which may be thought of as being somewhat similar in size and construction to the'body of a violincello but without a finger board or neck or other external attachments except possibly a handle 11 which may be employed in moving and manipulating the apparatus. This body 10 includes a top cover 12 connected removably by any suitable means to. the rim portion 13 and having also a bottom plate 14:.

The other main portion of-the supporting or casing construction is a hollow base or.

sub-support 15, the same being indicated as of generally rectangular form and-of rather shallow depth in proportion to its other dimensions. For convenience this base may be supported upon feet or legs 16- and 17, the latter being the shorter. The sub-support 15 except as now to be described is entirely closed and in itself constitutes a sound amplifying medium. The top portion or cover plate 18 is provided with a central opening 19 suitably shaped to receive therein the downwardly convexed central portion of the bottom of the body 10 which is clearly shown in Fig. 2. The len th and breadth of the sub-support 15 may e less or greater than the corresponding parts of the body 10, and these two main parts are in practice secured or anchored together by any suitable means, as for instance, the hooks 20 shown in Fig. 2. At any desired portions of the sub-support may be arranged sound vibration outlets each shown provided with a belllike sounder or extremity. For this purpose I show three of such members connected at and extending thence laterally sideways or I I and 23both of which are preferably of the nature of the commonly used B batteries for receiving sets. Within the body 10 I place a number of sound magnifiers or microphones of suitable construction and shown as four-in number at 24, one adjacent to each end of thebody and two others intermediate thereof, but all shown arranged in series or, if desired, parallel, and in the circuit with thetwo batteries just described. Whether the coupling be in series or parallel will depend upon the nature or make up of the receiving set. Also arranged in the same circuit are two loud speaking phones 25, one adjacent to each of the end microphones. The type of microphone best suited for this pur pose is as shown in Fig. 4, the same comprising a carbon base plate 26 and a tiltable or pivoted carbon stick 27 The stick is shown pivoted at 28 within a fork 29 of an insulated bracket 30 close adjacent to one side of the base plate 26. All the plates 26 are fixedg igidly to the bottom 14 of the body 19: One end of the-stick'27 is provided'with a series of fingers or teeth 31 having relav tively sharp points, and the stick is so 'designed that these points will rest with more or less heft upon the plates 26. The firmness of this contact between the stick and the plate is adapted to be varied or modified delicately or adjustably by means of a rider or weight 32v movable along the upper end of the-stick and adapted to be fixed in adjusted position by means of a set screw 33 or its equ valent. One connection of the circuit wire is made with the base plate 26 and the other with the stick, the latter connection being preferably through the pivot. It is the adjustable balance microphone feature of this invention that is relied upon, in connection with the B battery connections andloud speaking. phones 25, to produce the exceedingly well tuned-and well purified character tones, suitable for filling any reasonable room or auditorium, according to the. control at the adjustable receiving set. Of course-there is'nonecessity nor intention of employing head phones.

Located also preferably within the body '10 and-in close relation to the two intermediate microphones I provide' a number of other phones-34, preferably of the nature of loud speakin phones but which are coupled, indepen ently of the battery and head pieces.

wiring above described, to the receiving set in a manner similar to the usual coupling of The sounds received by and transmitted through the phones 5 and 34 pass through and are delivered from the sounding bodies 10 and 15 with a remarkable sweetness and purity of quality as Wellas depth of volume.

Variations may be resorted to within the spirit and scope of my invention and parts thereof used without others.

The microphone circuit is operated through the vibration of the adjustable microphones by the sounding body wherein they are contained, the vibrations of the sounding body being transmitted to the microphones 1 through the ,carbon base 26 attached to said body. These vibrations cause the resistance at 31 to vary so as to render the current flowing through the phones 25 a pulsating one, in unison with signals received through the primal set, causing them to operate so as to add to the total volume of sound to be amplified with- .in the sounding bodies 12 and 15.

I claim:

1. In a sound amplifying means, a body of violin form, a hollow resonant sub-support for said body which lies in direct contact therewith, a portion of the wall of one of which within the line of contact has been removed to allow the adjacentcontacting wall to form a single partition and common sounding board within said line, allowing the more ready transmission of sound therethrough for the purpose of amplification, and means to initiate sound vibrations to be amplified thereby.

2. Mechanism as set forth in claim -1 in which the resonant body is hollow and is provided with a convex bottom, and the sub-support is provided with an opening into which said convex bottom is fitted.

3. Mechanism'as set forth in claim 1 in which the sub-support is provided with a plurality of lateral openings.

4. In a sound amplifier as set forth, the combination of a hollow resonant body, a hollow resonant sub-supporting body therefor and to which the first mentloned body is secured in fixed position, a plurality of phones within one of the bodies operative from a radio receiving set to cause the vibration of the bodies, and microphone means within the body in an independent circuit for the purpose of amp ifying the sound emanating from the phones, said microphone means being operative by means of vibrations transmitted to the same at their points of attachment to the body.

5. The combination as set forth in claim 1 wherein the said means for initiating sound vibrations comprises a plurality of phones within one of the bodies operative from a receiving set to cause the vibration ofthe bodies, and microphone'meanswithin carbon base plate attached to said body, and 10 the same body in an independent circuit for a pivoted carbon stick one end of which the purpose of'amplifying the sound emamakes contact with the carbon base plate,

nating from the phones, said microphone the electrical resistance of said contact vai- 5 means being operative by means of vibra- 7 ing with the vibrations transmitted to t e .tions transmitted to the sweat their points microphone by the body. 15 of" attachment to the body. V Intestimony whereof I aflix my signature.

' 6. The combination asin claim 4 wherein the adjustable microphone consists of a r ALFRED N.'MA.RTIN.

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