US990973A - Sound-box for talking-machines. - Google Patents

Description

R. L. GIBSON. SOUND BOX FOR TALKING MACHINES. APPLICATION FILED NOV. 28, 1905.

WITNESSES Patented May 2, 1911.

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ROBERT L. GIBSON, F PHILADELPHIA, PENNSYLVANIA.

SOUND-BOX FOR TALKING-MACHINES.

Specification of Letters Patent.

Patented May 2, MPH.

,Application filed November 28, 1905. Serial No. 289,410.

means for supporting the stylus bar, and its object is to increase the sensitiveness and volume of the sounds transmitted without decreasing their timbre and sharpness.

In another application, Serial No. 284,640,

' liled October 27th, 1905, I have described a stylus bar support consisting-of a spring structure arranged at right angles to the plane of the diaphragm of the sound box, and the present invention relates to a supporting device of his general character.

More particularly the present invention relates to the employment in a supporting device of this kind of a leaf or llat spring supported at its ends transversely to the plane of the diaphragm and connected with the stylus bar between. its ends, so that, while great sensitiveness to direct vibration in the plane of the diaphragm is preserved,

the r sistance to lateral or torsional move ment incrcastal. not only is the construction ben ficial in increasing the amplitudes and accuracy of the sound transmitted, but it is simple, economical and easily applied.

ln the drawings: Figure l is an elevation of a talking machine embodying the invention; 2 is a front elevation of the sound box; Fig. 3 is an elevation of the upper edge of the sound box; and Fig. 4 is a transverse sectional view on the line X-X of Fig. 2 enlarged.

A is the rotating record carrying disk or table; it is the horn; (l is the swinging sound conveying arm; and .l) is the sound box suspended from the arm, with which'it may becohnected in any suitable manner.

While the particular construction of the sound l)0., .ide from the stylus bar support -is not material to my invention, I have, for purposes of illustration, shown a sound box of the gcl'ieral character shown in the Jones Patent No. (328,913, dated July 11th, 189$), in which the diaphragm 1 is clamped between flexible rings 1 F Within the head E of the sound box, and the tubular sleeve of the head G is .claniped between rings ll ll of nou-souiubconducting material. The stylus bar J is secured at one. end to the center of the diaphragm F the head.

in the usual manner and is provided atthe other end with a clamp K of any conven ient construction, tor holding the stylus or needle point.

The support for the stylus bar consists of a flat spring L, arrangedtransversely to the plane of the diaphragm and supported by It is connected with the stylus bar between its ends. In the construction shown, M is a frame carried by the head of the sound box and having notches m m into which the ends ofthe spring L are sprung, thereby curving the spring and putting it under tension. The bar J extends through the spring and frame M and may be secured to the former in any suitable manner, as by solder. lVith a spring support of: this kind extending transversely to the plane of the diaphragm, and hence to the plane of vibration of the point of connection between thestylus bar and diaphragm the stylus bar is made very sensitive to the direct vibration, while lateral or torsional vibration is practitatlly eliminated and this resistance to lateral or torsional movement is greatly increased by the use of the flat spring. This support, therefore, by reason oi its sensitive-ness to direct vibration and of its resistance to lateral or torsional movement transmits the sound Waves with great amplitude and accuracy, and not only increases the vol nine but preserves the timbre and tone.

\Vlrile it is not new to eoilnect the bar to a spring supported at its ends and arranged transversely to the plane of the diaphragm, in former constructions of this kind the spring is not the sole means of supporting and sustaining the stylus bar, but is the means of holding, the stylus bar on a fulcrum between a portion at the stylus bar and the head upon which the bar vibrates.

In my construction the spring arts not as a. means of holding the bar upon a stationary fulcrum but as the sole means of supporting the bar and the usual stationary fulcrum dispensed with. The bar vibrates at the point of connection with the spring and n on a stationary or fixed fulcrum.

What I claim as new and desire to se cure by Letters Patent, is as follows:

1. In a sound-box for talking machines, the combinationof a head or raise and diaphragm, a substantially rectangular tlat springsupported at its opposite ends only, said sole points of support and the spring being in a line transverse to the plane of the diaphragm, and'a stylus bar connected with the spring between the ends thereof, said spring having the function of a fulcrum and 'yieldingly'supporting and holding said bar in its normal position. v

2. In a sound-box for talking machines, the, combination of a head or case and diaphragm, a substantially rectangular flat Spring bent transversely to its length so as to be'under tension and supported at its opposite ends only, said sole points of support and the spring being in a line transverse to the plane of the diaphragm, and a stylus b? r connected with the spring between and in line with the ends thereof, said spring having the function of a fulcrum and yieldingly supporting and holding said bar in its normal position. v

3. In a sound-box for talking machines, the combination of a head or case and diaph'ragin, a supporting frame carried by the,

' yieldingly supporting said bar in its normal position.

4. In a sound box for talking maclnnes,

the combination of the head or-case and diaphragm, of a' transverse supporting frame M carried by the head and arranged transversely to the plane of the diaphragm,

the flat spring L havingits ends sprung into engagement with said support and extending transversely to the plane of the diaphragm and a stylus bar acting on the diaphragm and connected with said spring.

5. In a sound-box, a case having two supports arranged parallel toand at difierent distances from the diaphragm, a diaphragm located to one side of a plane through said supports, a fiat spring sprung between the supports so as to be under tension and in a plane at right angles to the plane of the diaphragm, and a stylus secured to the spring intermediate of its ends and supported wholly by the spring and-out of direct c0n- ROBERT L ernson.

Witnesses R. M. KELLY,

M. J. EYRE.

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