US1531252A - Electrical reproducer for phonograph records - Google Patents

Description

March 24, 1925. 1,531,252

E. T. JONES ELECTRICAL REPRQDUCER FOR PHONOGRAPH RECORDS Filed Nov. 25, 1921 2 Sheets-She s; 1 l l' MA H j'l'IwL 1 H Illll J 30 gwuz'mkvc Y rmomwdam March 24, 1925. 1,531,252

E. T. JONES ELECTRICAL REPRODUCER FOR PHONOGRAPH RECORDS Filed Nov. 25, 1921 2 Sheets-Sheet 2 Qwucnfoz Edi ardjzamas Jnes Patented Mar, 24, 1925.

UNITED STATES PATENT OFFICE.

EDWARD THOMAS JONES, NEW ORLEANS, LOUISIANA ASSIG-NOR TO WIRED RADIO ING, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

ELECTRICAL REPRODUCER FOR PHONOGRAPH :anconns.

Application fil ed November 25, 1921. Serial No. 517,554.

To 1! wlzmnit may concern:

Be it known that I. EDWARD THOMAS Jones. a citizen of the United States, residing at New Orleans, inthe parish of Orleans and-State of Louisiana, have invented a certain new and useful Improvement in an Electrical Reproducer for Records, of which the following is a specification.

My invention relates broadly to phonographs and more particularly to means for reproducing phonograph records.

The object of my invention is to provide an electrical reproducer for phonograph records arranged to reproduce sound records at sufiicient amplitude to be heard throughout the area of largehalls, auditoriums and amphitheaters and in the open air and wherever the usualphonograph is incapable of reproducing sounds with sufiicient volume to satisfy such occasions.

A- further object of my invention 1s to provide an electrical; reproducer which eliminates scratching and other external mechanical noises due, among other things. to

the mechanical vibration of the parts of the usual sound box rep'roducer.

A still further object of my invention is to provide a phonograph wlth means by whiclrthe tone and the volume of the music' mav be varied at the will of the operator.

Heretofore in the reproduction of phonograph music by electrical reproducers, it has been proposed to employ amicrophone mounted upon the tone arm of the phonograph and actuated by the stylus of the reproducer. In other cases magneto inductive systems have been proposed in which the tracing stylus imparts vibrations to a metallic armature arrangedto vary themagnetic reluctance of the reproducing circuit.

All of these prior adaptations have inherent disadvantages due to complications in con-.

struction and in the case of the microphone transmitter inherently poor electrical characteristics.

The present invention will be more clearly understood by reference to the following specification and the accompanying drawings in which Figure 1 1s a-dlagrammatic view of my electrical reproducer system for honographs; Fig. 2 illustrates on an eniiirged scale a 'hill and dale out sound rec- 0rd; Fig. 3 shows on an enlarged scale a transversely cut groove of a phonograph Phonograph and that the specific embodiment illustrated and described herein is only indicative thereof.

Referring particularly to Fig. 1 of the drawings, reference character 1 represents a phonograph cabinet having a record table 2 supporting a disc record 3. Carried by a swivel mounting upon cabinet 1 is an electrical reproducer 4 comprising sty us point 5 secured in holder 6 and secured to lever 7 pivoted upon pivot member Sat 9 and 10 upon mounting 11. The lever 7 is arranged.

to .mechanicallyvibrate a wound armature 12 in accordance with the motion of stylus point '5. through a systemoflevers 36 and 37. The wound armature 12 comprises a large number of turns of fine wire supported on axis 39 mounted within a strong concentrated magnetic field of force emanating from field magnets 14 and 15 carried bv mounting 11. A stationary iron core 38 is mounted on the frame 11 within the'area covered by the swinging coil 12 to complete the magnetic circuit and increase the magnetic flux' cutting the coil. The axis 39 is pivotally mounted on springs 34 and 35 -which provide terminals for electrical connections to the armature. The field magnets 14 and 15 are energized by winding 16 and 17 respectively, by a source of energy 18 through adjustable rheostat 19.

Connections are taken from the wound a1.- mature 12 within the magnetic field to a primary winding 20 of transformer 21. the secondary 22 of which connects to the input circuit of vacuum tube 23 arranged to amplify the energy generated by the mechanical movement of armature 12 in the magnetic field of magnets 14 and 15. The vacu um tube 23 has its output circuit associated with the inputcircuit of vacuum tube amplifier 24' through transformer 25 forming a second stage of amplification of the'energy generated in armature winding'12. The outphonograplr'at opening 29.

put circuit of 'vacuum tube amplifier 24 is connected to a loud speaker reproducer 26' having'an external source of energy 27 for the adjustment of its field. The degree of incandescence of the filaments of the vacu um tubes 23 and 2% may be re, ted by rheostats '32 and 33 respectively, hereby the degree of amplification and volume of reproduced musiomay be Varied at will. The loud speaker reproducer 26 is mechanically mounted with reproducing horn 28 through which music is conveyed'from the The electrical reproducer' is adapted for operation with a record of either the vertically cut groove type as shown in Fig. 2, wherein the stylus 5 isvibrated mechanic-ally over the hill and dale surface 30; or the record may be of the transverselycut groove type indicated in Fig. 3, wherein the" stylus 5 is mechanically actuated by the walls 31 of the record groo ve. p

' The armaturc lQ may be provided at its terminals or through its amplifier leads with terminals A B and connections taken to difa. vibratory line recordpermits an indication of the varying frequency of the musical selection. A visible study of the variation and modulation'of the musical selection can be made by connecting a frequency meter at the terminals A B'interposing the necessary amplification in the line. The reproducer is particularly adapted for oflice dictating macate like parts in these figures as in Figure 1. The terminals of the wound armature 12. are brought out to binding posts 12 while the terminals of the field magnets are brought out to binding posts -16.

In the operation of this apparatus the stylus point 5 of the reproducer is mechanically vibrated in accordance with the impressions upon the phonograph record. The armature coil 12 is vibrated through .its system of levers and its windings cut the magnetic field of magnets 14 and 15. generating energy therein in accordance with the musical vibrations which energy is amplified by the vacuum tube amplifier and thrown out to an audience at great volume.

.Having thus described my invention what I claim and desire. to secure by Letters Fatcut of the United St-ates is:

In a phonograph transmitter, a casing carried by an arm pivotally mounted relative to a sound record, a pair of hearings on said casing, a motion multiplying lever pivotally mounted in said bearings, a stylus carried by said levcr'on-one side of said pivotal mounting, a coil vibrated by said lever on the opposite side of said pivotal mounting, a permanent magnetic field surrounding said coil, and means whereby saidstylus mechanically vibrates said coil and generates energy therein.

EDWARD THOMAS" JONES.

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