US1739228A - Electrical reproducer for phonograph records - Google Patents

Description

Dec; 10, 1929. L. D. :HARRIS ,739,228

ELECTRICAL REPR ODUGER FORPHONOGRAPH RECORDS Original F fi ed June 12 1926 2 Sheets-Sheet l Dec. 10, 1929. 1.. D. HARRIS I ELECTRICAL REPRODUCER FOR PHON OGRAPH RECORDS Original Filed June 12, 1926 2 Sheets-Sheer 2 I Patented Dec. 10, 1929 v UNITED STATES LELAND D. HARRIS, OI SALT LAKE CITY, UTAH ELECTRICAL .REPRODUCER FOR PHONOGRAPH RECOBDS Application filed June 12, 1926, Serial j This invention relates to and has for one of itsv objects the provision of an electrical reproducer and amplifier for phonograph records which will eliminate all rasping and other'mechanical noises, which will reproduce the record. in the clear natural tones used in the making of the same, and which will permit the tone and volume of the music to be varied at the will of the operator;

With theforegoing and other objects in View, the'na ture of which will become apparent as the description proceeds, the invention consists of the novel construction, combination and arrangement of parts hereinafter fully describedand claimed, and illustrated in the accompanying drawings,

wherein:

Figure 1 is a view partly in elevation and partly in vertical section of the electric generator and modulator of the device,

, Figure 2 is an elevational view looking at the electric generator from the side opposite that seen in Figure 1, p

. -Figure 3 is a'sectional view taken on the plane indicated by the line 3-3 of Figure 2, Figure 4 is a detail elevational view of the armature and coil of the electric generator, Figure 5'is a sectional view taken on the plane. indicated by the line 55 of Figure 4,

Figure 6 is a detail perspective view of the armature and supporting frame therefor,

Figure 7 is a detail perspective view of the pole pieces of the electric generator,

Figure 8 is a detail perspective view oi the core of the coil, and

Figure 9 is a diagrammatic view of the electric generator, modulator and amplifier. Corresponding and like parts are referred to in the following description, and vdesignated in the several views of the accompanying drawings, by similar reference characters.

The electric generator comprises semi-circular permanent magnets 1 and 2 which are arranged with their like poles opposite each other and are secured in any suitable manner within a case 3. Pole pieces 4 and 5 which extend diametrically of the magnets 1 and '2, have their outer ends secured as at 6 to the ends of the magnets. These ends of the pole No. 115,524,. Renewed April 12, 1228.

pieces 4-and 5 are notched to provide air gaps 7, and the inner ends thereof are of substantially U-form, as shown at 4 and 5", and arranged within the magnets 1 and 2. The ends of the magnets l and 2 are relatively spaced. The polepieces 4 and 5 are posi-. tioned at one side of the magnets 1 and 2, and the air gaps 7 of the pole pieces occupy a position between the ends of the magnets. The U-shaped ends 4 and 5 of the pole pieces 4 and 5 are arranged at right angles to the plane of the pole pieces to permit them to extend into the magnets 1 and 2 as stated. A coil 8 is arranged withintheendsl and 5 of the pole pieces 4 and 5, and is mounted on A a spool which consists of a hollow metallic core 9 and sides 10 of bakelite or other suitable insulating material. The core 9 is provided with lugs 11 which contact with the outer it'ac es of the sides 10 to hold it, the sides and the coil 8 together. An open frame 12 carried by the core 9 and adapted to be" inserted therein from an end ther'eof, is provided with shoulders 13 to limit the extent .of its insertion into the core. An armature 14 is, rockably supported within the frame '12 by a spindle 15, and is provided with an Y nected'to thelug 16 of the armature 14 by a link 23. The terminals 8 of the core 8 are secured to binding posts 24 carried py the ' pole pieces 4 and 5. The ends 4 and 5 of the pole pieces 4 and 5 contact with the frame 12, to hold it against casual movement The thickness of the frame 12 is greater than the corresponding dimension of the armature 14 is order to permit the latter to vi brate ireelyjin unison with the stylus 18 as the latter travels over the phonograph record 21.

The case 3 is carried by a hollow arm 25 which is adjustable lengthwise in a sleeve 26 r'ockably supported as at 27 on a post 28. A set screw 29-permits the arm 25 to be secore 33, a primary win ing cured in adjusted position. with res ect to the sleeve 26. The post 28 is swivel y, c0n-- nected as at 30 to a case 31 in which is mounted a transformer 32 com rising a laminated 34 and a SEC,- ondary winding 35. Leads 36 extending from the binding posts 24 and through the arm 25, are connected to the terminals of the primary winding 34, and leads 37 no tending from the secondary winding 35, are connected to binding posts 38 carried by the case 31. V

The secondary winding 35 of the trans former 32 is. connected to the amplifier 39 shown, diagrammatically in Figure 9. This amplifier comprises vacuum tubes 41, 42 and 43, high ratio transformers 44 and 45, an A battery 46, a B battery 47, adjustable resistance 48, filter condensers 49 and 50, a high resistance by pass coil 51, and adjustable grid resistance 52.- The secondary 35 of the transformer 32 has connected thereto a plug 53 which is ada ted to be inserted in the input socket 54 o the am lifier 39. The amplifier 39 is also provi ed with an output s0cke t'55 to receive a plug connected to a loud speaker, horn, telephone receiver or the like.

From the ioregoing description, taken in connection with t e accompanyin drawin s, it will be understood to those skilled in t e art to which this invention relates, that the vibration of the armature 14 by and as the result of the movement imparted to the stylus 18 by the phonogra h record 21, 'will generate electrical impu ses of varying intensity in the coil 8, that these impulses are am 11- fied by the transformer 32, and that t ey are further amplified by the amplifier 39. It will be further understood that the device will reproduce the music recorded on a phonograph record without the scratchin and other mechanical noises incident to t e use of the usual sound box rep'roducer,-and that the tone and volume of the music may be varied at the will of the operator through the medium of the adjustable grid resistance 52. A loud speaker especially adapted for use in connection with this device is shown in my copending application, filed 12th day of June, 1926, andserially numbered 115,523.

It should be understood that the drawings are merely illustrative and do not pretent to give exact proportions. Furthermore, the said drawings are illustrative of a preferred construction, it being my expectation that various changes and modifications may be made without departing from the spirit and scope of my invention.

What is claimed is r 1. An electrical reproducer embodying semi-circular permanent magnets, pole pleces arranged-diametricall of the magnets and having their outer en s secured to a side of bein v of substantially U-form and arranged para lel to the plane. of the pole pieces and extending into the magnets, a coil located within the inner ends of the pole ieces, a frame extending through and beyon the coil and engaged by the ends of the pole pieces to secure: it and the coil in place, and an armatare arranged within and rockably supported by the frame.

2. An electrical reproducer embodyin a permanent magnet, pole pieces connecte at their outer ends to the same side of the magnet and having inner ends of substantially U form with their open sides facing each other in a vertical plane, a coil located within the inner ends of the pole pieces, an open frame extending throu h and beyond the coil and engaged at points eyond the coil by the inner ends of the pole pieces to secure it and the coil in place, and an armature arranged within and rockably supported by the frame.

3. An electrical reproducerembodyin a permanent magnet, pole pieces connecte to the magnet, a coil associated with the mag net, sides for the coil, a hollow core passing through the coil and sides and provided with In contacting with the outer faces of the si es, an open frame supported within the core, and an armature rockably supported within the frame.

In testimony whereof I afiix my signature.

I LELAND D. HARRIS.

the magnets, the inner ends of the pole pieces

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