US1119920A - Sound-box. - Google Patents

Description

C. E. WOODS.

SOUND BOX.

APPLICATION FILED AUG.26,1913.

Patented Dec. 8, 1914.

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CLINTON-1E. woon's, ossmnesros'r, CGNNECTICUT, ASSIGNCR TO AMERICAN GRAPE!)- rnonn COMPANY, VIRGINIA.

on-Bn-InGsPon'r, CONNECTICUT, 2-. CORPORATION OF TEST SOUND-BOX.

1"; all whom it may concern Be it known. that l, (Lii'rox ll. \Vooos, of Bridgeport, Connecticut. ,have invented a new and-useful Improvement-in Sound- Boxes, which improvement is ,fi il-ly.set forth in the following specification.

'l-his invention.relates .to sound boxes intended for use with lat-erallv undulating or zig-zagdsound records;

Heretofore in sound boxes for talking machines, it has been proposed to mount the diaphragm between two rings or as b kets of elastic material composed-ofjasuitable length of small rubber tubi hen ito circular form, the Whole bean secured in position in the diaphragm head unde com pression. In wholesale ,niaiiufacturing op erations, these pieces of small rubberfti bing I i i an inch too long or too short, there iusing either an o cerlappingof their adiaeei'it ends or, failure of the ends to meet ,irhenjn in the sound-box, rMoneover,Whenthe parts are assembled, it has been found that inmany cases the compressionis not: uniform. ;-Any or all of these causes girc rise to variations and defects in. the character of the reproduction. I Inthe manufacture of sound boxes prior to, the present invention, 'various attempts have been made to secure the. most advantageous relationfbetween. the stylus bar and its needle on'the,onehanfhand the sound box and its diaphi ag-mon the other. ring 3 5, tension has beenla ppliediihone 'directibn' or the other, and it. haseven" been proposed to provide two opposing spring-rtensions-in order to produce an equilibrium. :But] in manufacturingsoundboxes on a large scale, ithas been found-iinpractical, because of the unavoidable variations (even though minute) in the quality-"of the sprin sandcorr sequentlv' their action upon the parts in volved, to secure the desired equilibrium. And this results in agreat variation in the quality of the complete sound box and the character of the reproduction secured there from. Furthermore, it has been found dithcult to secure the inner end of the stylus bar to the diaphragm in such a. manner to unite the same effectively to the diaphragm Without danger of separation therefrom and without affecting the diaphragm Specification of Letters Patent.

Patented Dec. 8,"i914.

Application filed August 26, i913. Serial No. 786,730.

' sueha manner as to injure or alter the reproduction or the vibration of the diaphragm under the influence of the undulatrons of the sound record. If the stylus bar secured to the diaphragmby cement, it is found that it is liable to break loose, and inoreorer the cement itself is liable to extend over diilcrent areas in different specimens. hen an edort is made to clamp the vlus bar to the diaphragm by a screw and nut construction, the tightening of the nut tends to distort the diaphragm and to place the same under a torsional strain at the point of union. These differences also tend to introoucc variations in the characterof the reproduction secured from sound boxes othervi'ise pxactly alike. In short, in sound bones as heretofore constructed, and particularly when manufactured in large numhers by a large number of workmen, it has been found exceedingly d iflicult to produce or" the reproduction which cause the sound box, when tested at the factory, to be'dis carded, and in actual operation it has been found that a very large percentage'of sound boxes, when tested, have to be discarded because of variations due to one or more of the causes mentioned above.

The object of the present invention is to provide a sound box which can be manu factured in Wholesale quantities and which shall nevertheless give uniform results in the quality of the reproduction obtainedthereby, which shall be simple in construction, easilv assembled and disassembled for inspection or repair, and which can be i anufactured at a minimum cost.

il'ith these objects in view, the invention ts of a diaphragm mounted in a single egral ring of eiastic material, such as soft rubber of inc quality, and secured in a head in the form of a cup by any suitable means, such as a screw ring, for imparting uniform compression to the ring of elastic material, and a stylus bar preferably formed of a single.- piece of forged metal of uniform texture and quality pivotally mounted upon the frame of the sound box and securely attached to the diaphragm without placing the latter under any torsional strain. Preferably the inner end of the'stylus bar is bent and screw-threaded and extended through a central opening in the diaphragm, with a small fiat washer onjeither side of the diaphragm, which washers with the interposed diaphragm 'are clampedbetween two nuts screw-threaded onto the end of the needle bar. By this means, a sound box'is secured which is'exceedingly simple in construction and'cheap to manufacture, but which never- 1 the-less may be manufactured in large numbers by, a large number of workmen withoutvariation in the diaphragm mounting or the needle bar mounting, or in the attachment of the needle bar to the diaphragm, with the resultthat discards-in the manufacture are view; Fig. 2 is a side elevation partly in section; Fig. '3 is an enlarged sectional detail showing'thc manner of mounting the diaphragm in the frame or support; and Figs. 4, and 6 are detail views showing the mannor of connecting the stylus bar to the diaphragm.

in said figures, in which like reference numerals indicate corresponding parts, 1 is the diaphragm frame or support, here shown in the form of a cup having formed integrally therewith a hub or neck 2 by means of which the sound boxis connected to the tone arm. In the form chosen for illustration in the drawings, the diaphragm frame or support is in the form of a cup whose side walls B-are arranged at right angles.

to the bottom of the cup, the upper portion of said walls being formed with interior screw-threads 4, and the diaphragm 5,

I formed of any suitable or desired material is mounted in a single integral ring 6 formed of any highly resilient material, as soft rubber, the diaphragm being seated in an interior groove or slit formed in the ring I 6-. whieh'ring is held in position by any'siiitable" means for slightly compressing it and securing it in the frame or suppo'rtl, such means being here shown in the form of a ring. or bezel 8, screw-threaded oh its exterior periphery to engage the threads 4 in the frame or support. Preferably the diaphragm supporting ring 6 has formed on its face-adjacent to the ring 8 a groo-ye 9 which, when the ring 8 is in position, forms an air, chamber. 'lhis groove 9 not only serves as an air cushion, but also provides a reduced portion'of the rubber ring 6 n either side ofthe groove, upon which tl e ring 8 presses 'and thus insures, by reason of the reduced surface, a closer contactand more uniform bearing of the ring 8 upon -the resilient ring 6. lVhile the ring 8 1s shown as-a screw-threaded ring, any other suitable means may be employed for com pressing and retaining the resilient ring 6 in position. v

The stylus bar 10 is composed of a single piece of material, as drop-forged steel for example, and has two hubs ll'extending laterally from the sides thereof, the wholeheing preferably soproportioned that the center of gravity of the stylus bar is on a line 'iassing through the center of its hubs,.

which hubs have countersunk recesses in their ends forming bearingsfor pivot pins which are screw-threaded into ears 12 formed on or secured to the margin of the diaphragm frame or support and having ctmiCfll point-s which'enter the countersunk hearings in the hubs 11 of the stylus barn These screw-threaded pins l-2 h ai'e lock nuts 13' screwed on the outer ends thereof which project through the cars 12, thus enabling the pivot hearings to be precisely positioned and then locked securely in such position. The stylus bar is provided with the usual stylus receiving socket and set-screw 14- for securing thestylus 15 therein. The inner end ofthe stylus bar is turned at right angles' to' the main portion of the inner arm 10 and at its extreme end screw-threaded to project through zLcentral opening in the diaphragm, the stylus bar being provided with a suitable abutment against which the diaphragm takes bearing; This abutment may be in the forin of a shoulder 16, either formed iptegrallywith the stylusbar, as shown in Fig. 4. or preferably formed by a washer 19 abutting a nut 17 on the stylus bar. which nut is provided with a reduced surface close to the bar, which reduction is preferably secured by forming the nut either conical or spherical, as shown at 18. A. washer-19 is then slipped over the stylus bar. which washer has a flat side adjacent to the diaphragm, the opposite side of the washer being either also flat or slightly convex, as shown in Fig. 6. A second washer corresponding to the washer 19 is then *fitted over the stylus bar with the flat slde. adjacent to the diaphragm. and the whole secured in position by a nut :30 serewthreaded onto the extreme end of the stylus bar, which nut has its spherical surface 18' adjacent the second washer it), which ond washer if ma have its side adjacent to the second nut 2U either tapas shown in Fig. 5, or convex, as shown in Fig. 1'. In case the flat shoulder in integral with the stylus bar. as shown in Fig. l. the. diaphragmbears against such flat faced shoulder and the washer i9 is then placed under the diaphragn'i and .the convex faced nut 20 is screw-hremlcd thereon as in Figs. 3 and (3. And in either case. it will be observed that the surface of the tightening nut which bears against the washer reduced to a minimum. thereby eliminating the liability of the nut imparting any turning action to the washer. consequently avoiding any ternlency of placing torsional strain upon the diaphragm when the nut is tightened to lock the stylus bar to the diaphragm.

By mounting the diaphragm in the integral ringpf soft rubber, the diaphragm evenly and uniformly supported throughout its periphery and entirely restrained from coming into contact at. any point with the metal of the frame or support, and as these rings can all be made in a suitable mold and of uniform material, all of the diaphragm (when the sound boxes are made in va ole sale quantities) will be mounted under iileir tically the same conditions. and thelarg'e body of resilient material constituting the ring supports the diaphragm yieldingiy in the head of the sound box and tends: to an sorb any unusual shock due to undulations of great amplitude. in the record groove. While at the same time transmitting with perfect accuracy the vibrations due to undulations of lesser amplitude. thcrebv avoid ing what is commonly known as in the reproduction. Moreover, the i cncy of the ring is materially enhan ed by the presence of the air chamber the groove. 9, and the effective the screw-threaded ring or bezel R with rubber ring is also increased. so threading the ring 8, means are pro whereby the compression of the ring :1 nu) be increased if found necessary for any rea conta t of son, such as the aging of the rubber.

The uniformity of construction and the texture of the metal formingthe stylu bar 10 is secured by drop-forging the bar. and the perfect equilibrium of the bar is secured by placing the axis or fulcrum of the bar on a line passing through the center of gravity of the bar. Moreover, the means; by which the said bar is secured to the dia phragm are such that there is no iangi cr of imparting any torsional or other to the diapln'agm, and therefore the par secured by phragm and the stylus bar are normally in a state of equilibrium free from any tension or strain. H

While, for the purpose of describing the invention, the same has been set forth with considerable particularity. it is not to be understood that the'invention is confined to the specific details of construction or proportion and arrangement of parts herein set forth, since the same. may be greatly varied within the limits of the appended claims, without departing from the invention.

hat is claimed is:

1. In a sound box for talking machines, the combination of a diaphragm frame or support, a diaphragm yieldingly mounted in said frame or support; a stylus-bar piv otaily mounted on said frame or support and extending parallel with said diaphragm with its inner end screw-threaded and bent at right angles to and extending through a central perforation in the diaphragm, a pair fiat n; 19.!51- on said stylus-bar and cmbracing d diaphragm, and two screwthreaded -.:iamping nuts with sphericai surfaces cage ing the washers and clamping them against the diaphragm.

2. in a sound box for talking machines, the combination of a diaphragm frame or support, a ring of elastic material mounted in said frame or support and having an, annular green? or slot formed in its interior wall to receive the diaphragm and an annuiar groove or air chamber on its outer face, a tllilplilfifjiil mounted in said interior fzfroovc or slot, and means retaining said ring in said frame or support under presaud sealing: said air chamber or groove.

in a sound box for talking machines, the combination of a diaphragm frame or support and a diaphragm yieldingly mounted therein, with a stylus-bar pivotallj. mounted on said frame or support and provided with a screw-threaded arm having a shoulder thereon, said arm extending thr ugh a. central perforation in the diaphragni with the said shoulder abutting one face of the diaphragm, a flat faced Washer on screwihrtmded arm and abutting the other face of the. diaphragm, and a nut on said arm and having a. spherical Fare. bearing against said washer.

45in 2 nd box for talking machines. the crunifination a diaphragm frame or io t. a rubber ring rectangular in .-%ut.i )li mounted in said frame or support and having an annular air-chamber in one of its lateral faces, a diaphragm carried in an interior annular slit in said ring, and means securing said ring in said frame or support.

' 5. In a sound box for talking-machines, the combination of a diaphragm frame or support in the form of a metallic cup, a ring of elastic material seated in said cup and provided with an interior annular slit or groove, a diaphragm seated in said slit or groove, means securing said ring in position in said cup under compression, a stylus-bar formed of a single piece of forged metal pivotally mounted on said frame or support, and a S})l1(.ll('2ll-ftl(ftl nut on said stylus-bar and clamping said bar to the diaphragm between two llat surfaces, one of which is engaged by the spherical face of said nut. v i

G. In a sound box for talking machines, a screw-threaded stylus-bar, a centrally perforated diaphragm through which said bar extends, two elements on said bar one on each side of the diaphragn'i and each having a flat face engaging said diaphragm, and a clamping nut on said bar and having a sphcrical surface engaging one of said elements.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

CLINTON E. WOODS Witnesses:

JOHN R. ln'rmn, JOHN S. GRIFFITH.

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