US904523A - Sound-box for talking-machines. - Google Patents

Description

A. FISCHER. SOUND BOX FOR TALKINGMAGHINES.

APPLICATION FILED THE. 3, 1908.

Patented Nov. 24, 1908.

" Tigaa Iiqill Unless these springs ALEX FISCHER, OF KENSINGTON, LONDON, ENGLAND.

SOUND-BOX FOR TALKING-MACHINES.

Specification of Letters Patent.

Patented Nov. 24, 1908.

Application filed February 3, 1908. Serial No. 414,070.

To all'wkom it may concern:

Be it known that I, ALEX Frsorinn, a subject of the King of England, residing at 16 Maelise road, K ensington, in the county of London, England, have invented certain new and useful Improvements in the Construction of Sound-Boxes for Talking-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable in the art to which'it apperta-ins to make and use the same.

. This invention relates to improvements in the construction of sound boxes for talking machines of the disk type.

Hitherto in nearly all sound boxes the plate carrying the stylus and stylus bar is placed on knife edges or points and is pressed against the same by springs or .by some other devices. These springs or other devices also perform the function of holding the stylus and the stylus bar in position. or other devices press the plate against the-knife edges etc, tightly, there jarring, when the sound box .is played and in consequence the reproduction is bad. But this pressure also makes the stylus and the stylus bar rigid and, therefore, they are not freeand sensitive'enough to react to fine impulses of the stylus produced by the turning record. To improve this, I place the spindle carrying the stylus bar on two sensitive hin es as hereinafter described or in the known form of simple hinges or on center points which enter center holes in the plate, and I form an arm on the spindle which takes between two spiral or other springs. By these means the spindle will be quite free to react to the finest impulses, the springs having no other function than to hold the stylus and the stylus bar inposition. The reproduction, therefore, becomes broad in tone, soft and natural and full of shading. There are, however, other advantages as well in this construction. The tension of the diaphragm can be regulated to a nicety by-pushing the arm backwards or forwards as it "is maintained in position by means of the springs. Both springs may be screwedtighter or looser according to the requirement of the recordto be played or the nature ofthe diaphragm. And in order that mysaid invention may be better understood Iwill now proceed to describe the-same with others skilledv reference to the drawings accompanying this specification, in which Figure 1 shows a front elevation of a sound box constructed according to my improved invention. Fig. 2 is a side view of the same, partly in section. F ig. 3 is an edge view thereof. Figs. 4.- to 13, inclusive, show modifications and details hereinafter referred to.

The same letters and numerals of reference are employed to denote the same parts in all the views.

a shows the shell of'the sound box. On this shell I mount two brackets b, I).

0 shows. a spindle passing through the brackets b, b. To the spindle c is connected (or it may be formed therewith) an arm 01,

to which the stylus bar 6 is fixed. Attached at right angles to the arm 01 is another arm 7, recessed at each side.

9-, g are two other brackets in which are screwed hollow nuts 71..

it, is are two compression springs, one end of each of which passes into the hollow nuts it, and the other ends bear against the arm f.

Attached to the under part of the spindle c is a needle holder 4.

The spindle c is formed circular or partly circular incross section, and the brackets b, b are oppositely beveled so that thebearing surface on the spindle c is reduced to a minimum. .The spindle c to which the stylus bar 6 and the needle holder 4 are attached is in this way sensitively hinged to the shell a of the sound box. The tension of the diaphragm can be regulated by the action of the springs 7c and the hollow nuts 12. on the arm f. By screwing the front hollow nut in or the back out, the stylus bar, which is fixed to the diaphragm, will pull it (the diaphragm) and 'thus increase the tension of same. By screwing the back hollow nut in or the front one out, the stylus bar will lieplislietl towards the diaphragm and lessen the tension on same. Screwing the two nuts equally in, will not alter the position of the stylus bar, but will only stiffenv the springs; while screwing them both out equally, will make the springs weaker without affecting the po* sition of the stylus 'bar in any way.

The brackets marked b-through which the ends ofthe spindle 0 pass may be made with a bevel bearing or may be made of a thin ring or its equivalent so as to give the spindle ca minimum amount of bearing surface. The bracket b would then be formed with a' hole of similar shape to the cross section of the aforesaid spindle 0, namely circular or partly circular and in this form I may have either a bevel bearing or a thin part ring as aforesaid.

Fig; 7 shows cross section of the end of the spindle, but it may be made of an entire circle or any part of a circle.

Figs. 8 to 13 'show several modified forms of bracket bearings; Figs; 8 and 9 show cross section and side view of thin ring bearing; Figs. 10 and 11 show end elevation and side view of a bevel bearing having a hole which may correspondto the cross section of the end of the spindle or it may be made circular or partly circular. Figs. 12 and 13 show two corresponding views to Figs. 10 and 11 but of a thin plate bearing.

Fig. 5 shows front elevation, partly in section, of a modified form of sound box using the compression springs. In this case the spindle c has two circular ends which work in a bevel guide bearing Z).

The spindle c has at each end recesses intowhich compression springs fit such compression springs being held in position by screw nuts [1, held by brackets .9 attached to the shell a of the sound box. The rest of the construction may be the same as that at Figs. 1 to 3, that is springs 70 may also be fitted on either side of the spindle It may herebe observed that in place of spiral-springs such as those marked 70 flat springs may in all cases be fitted if preferred or found desirable.

In sound boxes so constructed the spindle carrying the stylus bar and needle holder turns, as shown, on a correspondingly formed guide bearing in the brackets 1), whereas in all other known constructions of sound boxes the spindle ,does not turn but rocks on knife edges, points or the like, including the known construction wherethe spindle is provided with center holes and turns again on center points in those center holes.

I do not wish to limit myself to spiral springs, taking between them the small arm on the spindle, or to the use of hollow nuts, as these may be varied without departing from the principle of my invention. I may also use one tension adjusting spring on one side of the spindle only, instead of two, or one on each side, as described. I may also construct a cheaper form of sound box Without diaphragm tension adjustment, where the s indle will be hinged as described, without .consists in having the end of the spindle cylindrical or partly cylindrical turning on a suitably formed guide bearing olfering the minimum amount of surface.

Referring to Figs. 1 to 3, 1 shows the back plate of the sound box. This back plate is pro vided with an annularlgroove 8, into which a rubber washer 2? (preferably tubular) is placed. a, a show two small brackets attached to the back 9. 'v is a flanged tube forming the'sound exit tube fixed on to the back of the sound box by center screws 10 screwing through the brackets 24 and into two center holes 00 in the flange of the tube '1). In this position the flange of the ring 4) presses tightly against the hollow rubber ring t, making a flexible sound tight joint, which will allow the sound box a small turn around its vertical axis,v the center screws forming the turning axis. ()n the tube 0 I form a boss 3 into which a spring pin 2 is fitted, such spring pin being provided with a flange 2 to limit its action, so that the bottom of the pin may enter a hole in the tone arm or trumpet in order to attach thesound box firmly thereto. 5 is a cap screwed on the boss y to hold the spring in osition.

Fig. 4: shows a simplified form 0 spring for the pin. Instead of having the spiral spring and cap 5 screwed to the boss y, I 5 have a rubber ring '3 assing round the tube 1) and over the head 0 the pin. At its lower end the spring pin is soformed that the sound box can only be turned in one direc: tion, suitable means being employed to prevent the spring pin from turning round its vertical axis- Two holes (preferably opposite one another) are provided on the small end of the tone arm, on to which the sound box is pushed. In these holes the pin 2 springs, which will lock the sound box to the tone arm in the playing position, and

with a half turn the sound box will be brought in, position for changing the needle easily. The sprin pin at its lower end is out on the slant an will allow the sound box to be turned roundin the direction as indi- 'cated by the arrow (Fig. 4) while a turn in the opposite direction will be impossible. By turning the sound box the pin held down 1 15 by the spiral springs and cap or rubber ring will be pushed up, or slide upand ride on the top of the sound arm until the hole is reached again. An annular shallow groove may beprovided on the'tone arm connecting the two holes to form a guide for the pin to prevent the sound box from slipping off when not locked in the holes.

I may also use on the back of the sound box instead of the screws w, the brackets u, and the center holes a; on the flanged tube '0, other equivalent devices, say, hinging the flanged tube by simple hmges so as to allow a slight turn around its vertical axis.

In other respects the shelle and the back ofthe sound box are of known type, but I may in some cases construct them as shown in detail at Fig. 6, in which figure the back r of the sound box is formed in two portions, rtion 6 of which is fixed to the shell a oi the sound box. There is also a center portion 7 which is screwed or pushed into the ring portionfi and screwed therein or otherwise suitably fixedat any required distance from the diaphra This construction will allow variation of the air space between the diaphra m and the back l so form the shell part a in two (p'ortionamaking a separate ring portion an a ring 8 screwing into same. This construction also enables the pressure of the two rubber gaskets which hold the w diaphragm between them to be varied, by

of afcasing, a diaphra screwing the ring 8 into the shell portion a.

What I claim and desire to secure by Letters Patent of. the UnitedStates of America 13 lgln/a talking machine, the combination in said casing, a

pair of ide bearin srigid with said casing, a spin] leprovide with a circular side mounted in said guide bearings, a stylus bar attached to the said spindle and diaphragm, an arm carried by said spindle, a pair of brackets on said casing, a pair of springs, one on each side, of said arm, located between said arm and said brackets, in line with each other and pppositely located, and

to the said a needle holder attached to said spindle, substantially as described.

2. In a talking machine, the combination of a casing; a diaphragm in said casing; a pair of perforated brackets rigid with said casing; a spindle provided with a fiat and a circular side mounted in said brackets; a stylus bar attached to saidspindle and to said diaphragm; a pair of springs for controlling said bar; a pair of hollow nuts for controlling said springs; and a needle holder also attached to said spindle, substantially as described.

3. In a talking machine, the combination of a casing; a diaphragm in said casing; a pair of oppositely beveled perforated brackets rigid with said casing; a spindle provided with a fiat and a'circular side mounted in said brackets; a stylus bar attached to said spindle and to said diaphragm; a second pair of brackets on said casing; a pair of springs for controlling said bar; a pair of hollow, nuts for controlling said springs mounted on said second pair of brackets; and a needle holder also attached to said spindle, substantially as described.

In testimony whereof, I affix my signature, in presence of two witnesses.

ALEX 'rrscnna Witnesses I Lirrr SIMMONDS, A. Booms n.

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