US1347113A - Turntable for phonographs - Google Patents

Description

J. G. MERR IAM.

TURNTABLE FOR PHONOGRAPHS.

Patented July 20, 1920.

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70.501074 GMerriam. %1 Mtozwew yaw 96 1. G. MERRIAM.

TURNTABLE FOR PHONOGRAPHS.

1,347, 1 13, f Patented July 20, 1920.

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' wow/to u :UNITED STATES; P T- JOSEPH e: MERRIAM, or MERIDnmcoNNEoTIcUT, AssIGNoR TO J. COMPANY, OF MERIDEN, ONNECTICUT, A FIRM COMPOSED or J.

A. W. FOSTER, AND MERRIAM.

TURNTABLE non PHONOGRAPHS.

Application filed June 22', 1917.

To all whom it may concern:

Be it known thatI, JOSEPH G. MERRIAM, a citizenof the United States, residing in Meriden, county of New Haven, and State of Connecticut, haveinvented a certain new and useful Turntable for Phonographs, of which the following is a specification.

This invention is a turn-table for phono graphs and relates to improvements in such devices, with a new to overcomlng defects well known to those skilled in the art.

. .Turn-tables, as now employed, are generally made in the formof grayiron castings, and, as they embody a comparatively thin, broad expanse, they are usually taken from the flask in a slightlywarped condition, due to unequal shrinkage during the cooling of the molten metal. It is the practice to thereafter place the turntable face down upon a truesurface andpeen thesame, 2'. 0., hammer the back of the casting, to, bring all parts of the face thereof into engagement with said true surface. This peening operation is generally carried on around the edge or circumference of the casting, and, in .order thatsaid casting Will maintain the position into which it is peened, the circumference thereof is generally provided with a downwardly extending flange and it is on this flange that the hammering is received.

Experience has shown that, when a turntable is peened in the manner described, the hammer leaves marksin the circumferential flange of the casting which render the same uneven, thereby .requiringthat the flange be trimmed or machined in order not tointerfere with the operation of the phonograph brake mechanism or leave an uneven surface which might cut the fingers of a person inadvertently touchingthe same when applying a record tothe turn-table. When the flange is machined as described, it is. neces sary to frequently cut sufficientmetal therefrom, before the hammer -marks are removed, to preclude said flange from carrying outitsfunctions. Thus,-after a casting has been properly peened,the. flange, after being trimmed, may be of insuflicient body to hold the casting in the true form-into whichit has been forced during the peening operation, with the result that, as the flange is cut away, the casting will: assume. its original, warped condition.

Specification of Letters Patent.

T OFFICE.

e. MERRIAM G. MERRIAM,

Serial No. 176,256.

Another well known disadvantage in turn-table construction is the extreme weight or ponderosity thereof. In operating a heavy turn-table, it. is necessary to employ a motor equal to the task, and thus, in many cases, large, cumbersome where, if the turn-table were lighter, a much smaller motor might be availed. of. This not only adds to the weight of the machine, but materially increases the cost thereof. Somev attempts have been made to overcome this dilfculty by counter boring holes in the pattern, but this operation does not reduce the turn-table to the required weight, and is laborious and costly..

lVith the foregoing considerations in mind, the object ofthe present invention is to provide a turn-table"embodying the usual cast plate with thecircumferential flange, but having associated therewith; an additional-flange positioned interior ofthe circumferential flange, which additional flange is adapted to receive the blows transmitted during the peening operation, and provides a sullicient mass of metal to maintain the casting in the position into which it is forced during this operation. Said. additional flange nny' also serve as a braking flange when employed with machines adapted to brake the. turn-table from the under side thereof. I

. A furtherobjectof the invention is to form the body, of the turn-table from a plurality of bands or ribs with intervening interstices, which bands or ribsare so placed that, when, the turn-table vis cast center, the flow of molten metal to all parts of the mold may be speedily ac complished because of the particular placement of the ribs and their holes or other defects in the casting will be obviated. In this manner, a very light, yet strong and rigid, turn-table is produced, with a great saving of metal and the obviating of the necessity of using relatively high power motors for the operation of the phonograph with which the turn-table is associated.

Features of the invention, other than those specified, as well as theadvantages, thereof, willbe apparent from the hereinafter detailed description taken in conjunction with the accompanying drawings.

Patented July 20, 1920.

motors .are used from its intersections, whereby blowr in the'flanges'c-andt to assure'rigidity of Another adva as brake in'this manner. V I e q ture", however, 'in the employment o'f-the flange'c is that the peripheral or circurn- -invention,-. and

In theaccomp'anying drawings, I have accordance with the present invention. v

i Fig. 2 is a-section on the line 2 -2 thereof. 7 Fig. 3 is a view similar to that of Fig. .1, but showing a slightly modified form of the Fig. 4; is fLSGCtlOIl on line 4& of Fig.

- Referring to the drawings, and more particularly. Figs. 1 and 2, A designates a turntableembodying a'relatively thin-plate, C of substantially flat, circular configuration,

providediat the center ofits under side with a'hub B. Theliub isapertured, as usual, to receive the operating shaft of a phonograph;

Plate Cis provided at its periphery with-a depending, circumferential flange'c, and im' mediately inside of said flange with a second,

lower and broader flange c, as shownin Fig. 2. Thus, plate C is bordered by flange is thickened immediately nterior of 0 and said flange by virtue of flange 0; Experiment-has shown that-flange c" is of considerable practical importance, since it allows of the peening operation, subsequently to the'casting'of' the platejon the face of the flange, which is normally concealed by the deeper flange 0. Moreover, said flange 0 may 'b'e'trimn ed'," after the peening opera tion, withoutcutting flange c or decreasing the mass of metal initially cast therein. Thus, after the plate has been trued-up, and

. the f ceof flange c trimmed, if necessary,

there still remains ample and suflicient metal the edge of the-plateand preclude the same from warping or returning to its initial, warped condition,"in which t may have been subsequent to the casting operation and be fore the peening operation.

with the adjacent vertical edge of flange c;

to-fori'n a brakingangle for 'such machines The salient feaferential portion of the plate is extremely e V rigid'and willrun'true, said flange serving 1 to withstand any tendency of the 'plateto Warp- 1 The incorporation of the flange, as'described, in turn-tables-as'now constructed e v V flowing from the employinent offlange c is that, when in use, 1 thelface of the flange furnishesa smooth V to ferred form, is of a sort of lattice-work formation, embodying intei'secting b ands'forining' diamond shaped .intersticesi The arran geri'ient ofthebands niay vary, "but a very practicalform of construction is shown in ,F ig. .1, where certain of the bands dextend radially from the central portion of the plate to the flange '0, while other of the bands d"extend.'o'bliquely from bands cZ so as to intersect .oneanother and terminate at the flange c. "This formation is one of the most satisfactory froma manufacturing standpointand' does notpossess merely es thetic attributes; It particularly recommends itself to the casting art, itbeing manifest that} a fconstruction of the character shown inay be readily molded and'thereafter cast from its center with-the best result's. This is for the reasonth'at there .are; 7

no blind alleys into which the molten metal passes. The metal'flows froni the cen ter of the moldina general outward direccrack usually providedbetween theflask'sec tions at the outer edges of molds, and will not become entrained in blind'f'alleys and cause blow-holes. 1 The turn-table shown similar in "constructionto that of Fig.1" 1, embodying a p'late C, ai hub B",-and flanges f and f, {correspondingtothe flanges i and 0', The main difference between the two structures is thatjwhile theouter edgeoff the plate inFigs". 1 andQ is shown as perpendicii'lar tothe face ofthe plate, the oiiter edgeof thestructure shown in Figsi8 and 4 is 'rounded ov'eif, andthe bands 6, which cor%' respond to the radial'bands d, are curved matador straight-. Furthermore, thebands e; which correspond to-the bands d", are 7 alsocurved longitudinally to harmonize with the curvature ofthe'bands 61:. In the construction of Figs. 3 and eat interstices e correspond tothe interstices cl of the preferred construction, are'alsosuhstantially diamon'dfshaped. 'However," be

tween each two ac'erit ba nds' e, which are curved n opposite directions; as shown, for

'the purpose ;.of dividing the plate into sector sh'aped motifs, the interstices J 0 are made substantially square or rhomboidal for-the pi' rpose 'ofobviating the-iematiom of blind alleysin the moldorpassages therein through which; a retrograde movement of the metal to fllltlie same would be required. In the modified emanation; thev flow of the metal during the-casting operation is free and uninterrupted, blind alleys are absent, and blow-holes are avoided, while the resulting structure is light and rigid.

A turn-table constructed in accordance with either embodiment of the invention described has the advantage of being eX- tremely light, yet very rigid, and, when provided with the double flanges c and 0, is so constituted that warping will not result, since the peripheral portion of the turntable is in the form of a rigid rim spaced from the hub by an open-work portion formed from diagonal bands. This will give maximum rigidity with a minimum tendency to warp during the casting operation as well asduring subsequent use. The placement of the bands is such that the plate will not even have a tendency to warp, though, if it should, the rigid rim will absolutely preclude such deflection.

In casting the foregoing structures, I prefer to use the usual flask, common to the art of casting, but, in conjunction therewith, I employ a match-plate and position the pattern on the match-plate, thereafter completing the molding and subsequently casting in the usual manner. So far as I am aware, I am the first to ever cast a turntable through the use of a match-plate fixed to produce the desired form of the turntable to give the desired weight through the use of a perforated pattern fastened to the back of the plate. When the turn-table is cast as described, the tendency of the casting to warp while solidifying is minimized. Notwithstanding the fact that match-plates are known to the casting art generally, they have never been employed in this manner in the production of phonograph turn-tables, the method of producing such devices being of a less eflicient nature. Experiment has shown that the old and well known methods heretofore employed are far surpassed by the use of a match-plate as described, both in efficiency and in the results achieved.

Having thus fully described the invention, what I claim as new, and desire to secure by Letters Patent, is:

1. A turn-table for phonographs embodying a relatively thin, circular, cast plate provided with a centrally disposed hub and having a relatively deep, narrow, faced flange depending from the outer circumference thereof, and a peening flange of less depth but greater width than the face of the circumferential flange also depending from the under side of the plate in a position directly adjacent the circumferential flange.

2. A turn-table for phonographs embodying a relatively thin, circular, cast plate provided with a centrally disposed hub and having a stepped flange depending from the circumference thereof, with the deepest step of said flange adjacent the circumference of the plate, the lower and inner step of the flange being relatively broad to provide a peening surface, and a deeper or outer step thereof being relatively narrow.

In testimony whereof I have signed my name to this specification.

JOSEPH G. MERRIAM.

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