US1448090A - Phonographic sound box - Google Patents

Description

Mar. 13, 1923. 1,448,090

W. SCOTT -HONOGRAPHIC SOUND BOX Filed July 50, 1921 -l N VEN TOR.

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Patented .Mar. 13, 1923.

WALTER S COTT, OF SHERIDAN, WYOMING.

PHONOGRAPHIC SOUND BOX.

Application filed July 30, 1921. Serial No: 488,566.

. the accompanying drawings.

This invention relates to sound boxes for phonographs, telephones, and like instruments, and particularly to means for reinforcing and modifying the sound transmitted from the sound box to the amplifier.

The general object of the invention is to provide a sound box whether for phonographs or telephones having adjacent the diaphragm a plurality of stretched coiled springs extending transversely across the space behind the diaphragm, the sound waves acting to vibrate these springs and a being reinforced by, the vibrations of the springs.

A further object is to provide a sound modifier of this character which may be in.- serted in sound boxes.

And still another object is to so construct the sound box as to secure full vibration for the springs.

My invention is illustrated in the accompanying drawings, wherein Figure 1 is a front elevation of a sound box constructed in accordance with my invention;

Figure 2 is a like view to Figure 1, but with the diaphragms broken away and the bar 19 broken away;

Figure 3 is a section on the line 33 of Figure 1;

Figure 4 is a plan view of thespring supporting ring;

Figure 5 is a fragmentary sectional view of the spring supporting ring;

Figures 6 and 7 are face views of the two diaphragms. 1

Referring to these drawings, 10 designates the body of'the sound box which is formed to provide the usual sound chamber 11 and to provide aseat 12 for a gasket 13. Resting upon this gasket is a transversely extending diaphragm 14. whichextends diametrically across the sound chamber 11 andwhich has a uniform width except at the ends where it is rounded to fit the gasket,

this diaphra m thus leaving open. spaces on by a suitable gasket 15 is a second. diaphragm 16 which is circular in form so as to fit snugly within the circumferential wall of the sound box, this second diaphragm being spaced from the diaphragm 14 by the gasket 15 and being held in place by a gasket 17. Preferably this gasket 17 is engaged by an externally screw-threaded clamping ring 18 so that pressure may be applied to the gas kets and to the two diaphragms to hold the same in place.

The stylus bar is pivotally mounted upon the side wall'of the sound box, and to this end I provide a transversely extending supporting member 19 formed with an outwardly projecting lug 2O perforated for engagement with a stylus 21, this being held in place by a set screw. Attached to this member 19 is the arm 22 which is engaged with the diaphragm 16. The member 19 is held to the wall of the sound box. by two screws 22 which extend through relatively large apertures 23 in the member 19 so that the stylus barhas a rocking movement on these screws. Small rubber gaskets 23 are jacent wall of the sound box so that the member 19 has the least possible rocking engagement with the wall of the sound box.

The. inner end of the sound box is provided with the neck 25 having a gasket seat 26 defining a' central throat or opening 27.

Resting against this seat is a gasket 28, and i v disposed on this gasket is the outwardly flanged end of a slit tube 29. Resting against this flanged end is the gasket 30, this gasket being held in place by the annulus 31, through which screws 32, pass. The slit tube 29 is slitted at its outer end. The neck 25 is also slotted and a pin projects radially from the slit tube-into this slot or notch.

The means for modifying the sound and reinforcing the sound vibrations comprises a metallic ring 33, preferably of resilient material. whose ends are hook-shaped so that the ends of the ring may be engaged with each other, this ring being formed with a plurality of small, struck-up tongues 34'withwhich a plurality of transversely extending coiled contractile springs 35 are engaged.

These springs extend transversely across the sound box-preferably parallel to the arm 21 and at right. angles to the longer axis of the diaphragm 14;. The ring 33 is disposed on a seat 36 formed between the throat 27 of the sound box and the Seat 12. These springs in actual practice will have coils of approximately -3," in diameter more or less and will be very closely coiled. An ordinary sized sound box will have eight springs, the springs being set relatively close to each other so that the springs cannot fail to be vibrated by the pulsations of the air within the sound box and in the sound chamber.

I am aware of the fact that it has been proposed to reinforce sound vibrations in the sound boxes of telephones by the use of radially disposed coiled springs, which springs are supported, however, only at their inner ends and are not stretched strings, but I have found in actual practice that in order that these springs shall be stiff enough to stand radially outward that they will not be caused to vibrate by sound vi-v brations. Obviously, if any of these springs should at'their ends touch the diaphragm or touch the metal of the sound box, they would cause a rattling noise which would be unpleasant. Inasmuch as the springs in my device are supported at opposite ends and the springs are relatively taut or under tension, it follows that there can be no contact between the springs on either the diaphragm or the metal of the sound-box. I am also aware of the fact that it is common to provide stretched strings extending along the amplifiers of phonographs, these strings, however, not being coiled springs. Inasmuch as they are not stretched across the path of movement of the sound waves, they are not strongly affected by the sound waves or vibrations.

Particular attention is called to the fact that there are two diaphragms in my construction and that the inside one has its lateral edges cut away so that the diaphragm acts to .cause thesound waves to strike against the ends of the springs and cause the full vibration of the springs.

I do not wish to be limited to the use of this device with phonograph sound boxes,

as it may be also used in telephone soundboxes, megaphones, and the like.

I claim 1. In a sound transmitting instrument having a sound chamber, a series of coiled a series of coiled contractile springs extending parallel to each other and under tension, said springs of different lengths and extending diametrically across the sound chamber adjacent the diaphragm.

3. In a sound transmitting instrument having a sound chamber and a diaphragm and behind the same, a ring disposed within the sound chamber in spaced relation to the diaphragm, and a series of coiled contractile springs attached at their ends to said ring and extending diametrically across the ring and in the path of movement of the sound waves and under tension.

4:. As an article of manufacture, a sound modifier for sound transmitting instruments comprising a resiliently expansible ring, the ring being split, and a series of coiled contractile springs disposed closely adjacent each other and extending transversely across the space defined by the ring and connected at their extremities to the ring, the springs being under tension.

5. A phonographic sound box having a sound chamber, a diaphragm extending across the sound chamber, coiled springs extending, parallel to each other and under tension and disposed immediately behind the diaphragm and extending across the path of the sound waves, the rear wall of the diaphragm having an opening Whose axis is at right angles to the plane in which the springs are disposed.

6. As an article of manufacture, a sound modifier for sound transmitting instruments comprising a resiliently expansible ring having inwardly projecting, oppositely disposed tongues extending inward from the ring, and a series of coiled, contractile, stretched strings under slight tension having their ends engaged with said tongues and supported thereby, the springs extending parallel to each other and transversely across the ring. a

In testimony whereof I hereunto aflix my signature. WALTER SCOTT.

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