US1487371A - Reproducer for phonographs - Google Patents

Description

March 18, 192 1." 1,487,371

I C. E. BROWN REPRODUCERFOR PHONOGRAPHS Filed March 6, 1923 avwmtoz 0,5 .Brown l fter. id, 1924..

ltlTll STATES CORA. E. BROWN, OF WHITE PLAINS, NEW YORK.

REPRODUCER FOR PHONOGRAPHS.

Application filed March 6, 1923.

To all whom it may concern:

Be it known that I, Come E. BROWN, a citizen of the United States, and a. resident of lVhite Plains, in the county of West chester and State of New York, have invented certain new and useful Improvements in Reprodncers for Phonographs, of which the following is a specification.

The object of the present invention is to provide an improved form of reproducer, or similar device such as a recorder, for a pl'ionograph instrument, in which the sound waves or vibration from the diaphragm are permitted to pass directly from the outer portion of the diaphragm, into the connecting tube that leads these sounds or vibrations into the tone arm.

In the accompanying drawing illustrating one embodiment of my invention, Fig. 1 is a front elevation.

Fi 2 is a vertical section.

Fig. 3 is a bot-tom plan view, partly in section.

'Fi g. 4- shows the frame or casing.

l ig. 5 shows the connecting tube.

As shown in the drawing, the reproducer comprises a frame having an annular portion 2 and a rear plate 3, that may be integral if desired. The portion 3 suitably supports the diaphragm 4 that is shown as mounted between rubber rings 5, 5, secured by a ring At the lower portion of the finale ring 3 is pivoted a bracket 7 carrying the stylus arm 8 whose upper end 9 is secured at the center of the diaphragm 4. The bracket 7 also carries the stylus 10.

h rear plate, instead of having a small opening at the center, is provided with elongated narrow opening or slot that eX- tends from the edge of the plate inwardly toward the center. In the form shown I provide a slot 12 that extends radially inward from the margin of the rear plate to a place 13 a short distance beyond the center of the plate. This opening through the rear plate leads into a tube, that is mounted on the tone arm as usual, so that the bore of the tube will surround this slot 12. In the arran gement shown I provide a tube 14% having preferably a tapered bore 15 with a slot 16 in one side of the tube. This tube is so attached to the outer face of the rear plate that the slot 16 will register with the slot 12- in the rear plate. This tube is mounted on a flat supporting plate 16 that may be in- Serial No. 623,088.

tegral with the tube, and that extends be yond the tube for convenience in securing to the rear plate, as by screws 18, which rear plate 2 carries a block 21 similar to plate 17 A rubber gasket 19 is interposed between the plate 17 and the block 21.

The inner end of the tube bore is shown as rounded. The end portion 20, of this tube projects beyond the supporting plate 16 and is positioned a short distance beyond the rear plate, so that this end portion, that is tubular, can be attached to the end of the tone arm in any suitable manner.

From this arrangement it will be seen that the vibration in the stylus arm 8 imparted to the diaphragm a, will cause the sounds and vibrations to pass into the long slot 12, and it will be seen that the outer end of this slot is opposite the marginal portion of the diaphragm, while the slot extends to within a short distance of the center of the rear plate, and which is nearly opposite the center f the diaphragm. These vibrations will thereby pass through this slot in the rear plate, thence through the slot 16 in the tube into the bore of the tube. This bore is rounded at the inner end and the sound waves and the vibrations will find exit through the tapered tube, passing into the tone arm.

A reproducer made as set forth has been found to give very superior results. Where the sounds or vibration had to find exit through the small circular center opening in the rear plate, distortion was produced because the sound waves had to concentrate. With the new construction having the slot extending from the outer margin at the edge of the diaphragm, the tones and vibrations pass directly rearward without distortion, and this applies especially to the overtones and the high tones that pass rearward through the slot into the connecting tube, thence into the tone arm.

What I claim is A reproducer comprising a frame provided with a diaphragm and a stylus arm attached to the diaphragm, the frame having a rear plate provided with a comparativel narrow radial slot that extends from the margin inwardly and a connecting tube secured to the rear plate with its bore communicating with said slot.

CORA E. BROWN.

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