US2078113A - Sound recording apparatus - Google Patents

Description

A ril 20, 1937. o. ZECHA SOUND RECORDING APPARATU S Filed 001/. 25, 1955 Patented Apr. 20, 1937 PATENT OFFICE SOUND RECORDING APPARATUS Otto Zecha, Vienna, Austria Application October 25, 1935, Serial No. 48,758.

In Austria February 14, 1935 4 Claim.

This invention relates to improvements in arrangements for cutting sound records by the employment of an ordinary talking machine of the kind in which the rotary movement of the centre 5 pin of the turntable of the talking machine rotates a screw threaded guide spindle which is supported in a bearing at one end only and is prevented from participating in the rotary movement of the centre pin of the turntable by a nut riding on said screw-threaded guide spindle and connected by a pivoted connection with the supporting arm of the sound box carrying the cutting needle.

The essential feature of the present invention consists in that the pivoted connection is attached to the supporting arm of the sound box by means of an intermediate member which is adjustably secured to said pivoted connection and is provided with means for its removable attachment to said supporting arm, in order to permit .the application of the arrangement to differently shaped sound box supporting arms.

In view of the provision of the adjustable intermediate member it is possible to use the arrangement for cutting sound records in connection with sound box arms of different shapes, e. g. bent sound box arms or straight sound box arms. In view of this construction it is possible to place the intermediate member at different angles with respect to the said pivoted connection, in order to safeguard the same distance between the sound box and the nut riding on the screw-threaded guide spindle no matter of the shape of the sound box arm. Thus the arrangement for cutting sound records can be used in connection with any type of talking machines and soundbox arms.

A form of construction embodying the invention is shown by way of example in the accom panying drawing, in which:

Fig. l is a perspective view of recording ap paratus according to the present invention.-

Fig. 2 shows a detail of the same. Figs. 3 and 4 are side elevations showing how the record disk is mounted on the turn-plate.

Referring to Fig. l, the sound recording apparatus according to the inventionconsists essentially of a two-part articulated guide rod 9 adapted for coupling by one end to a distancing piece 8 to which there is riveted an adjustable strap 1 for attachment to the sound-box arm 5 i of the gramophone. To the other end of the guide rod 9 there is secured a half-nut III which rides on the conveyor spindle II, the screw threading on the inside of the half-nut being in '56 engagement with the threading on the outside of the conveyor spindle. Spring means associated with the nut III or the inherent resiliency of the walls of this nut serve to retain these two parts, nut and spindle, firmly in engagement with each other. The one end of the spindle l I is supported in a casing l2 adapted to be fitted, by means of a slotted sleeve 13, over the centre pin integrally formed on the end of the main driving shaft of the gramophone. A helical spring l4 fitted over the sleeve l3 presses this sleeve into grippi g contact with the main driving shaft of the gramophone, and causes the rotary movement of this shaft to be transmitted from this sleeve, through the intermediary of bevel'or worm gearing housed in the casing l2, to the conveyor spindle H.

The record disk 3 does not lie directly upon the turn-plate l but upon an interposed facing disc 2 (see Fig. 3). This disc 2 is provided with a rough under surface 2' with which it bears against the turn-plate I, and on its upper side with prominences or studs 4 adapted to engage in suitable apertures in the record disk 3, so that the record disc and the facing disk constitute as it were a unit. The frictional resistance between the rough under surface 2 of the facing disk 2 and the tum-plate I is so great that it is certain to exseed that resulting from the pressure of the groove cutting needle. If desired the engaging studs or the like can be dispensed with, in which case the upper surface of the facing disk is also roughened or provided with a rough coating. This rough coating can be made to cover the entire surface of the facing disk, or may consist of single segments or otherwise shaped pieces or strips which may be radially or tangentially disposed or in the form of annuli. The conditions could of course also be reversed, the record disk being provided on its under side with a rough coating or engaging studs and thus anchored to the suitably constructed tum-plate or facing disk. If desired, the anchoring could also be effected by means of an annular or disc shaped attachment adapted to grip the record disk at its outer edge or at its centre by means of studs or the like and to engage in suitable holes or recesses in the facing disk or tm'n-plate.

In the form of construction shown in Fig. 1 the facing disk 2 is provided with studs 4 adapted to engage in holes in the recording disk. The end I! of the helical spring I is formed into a loop or 50 ring adapted to fit over one of the studs 0, thus still furtherincreasing the security of the hold between the recording disk 3 and the facing disk 2.

Before recording is commenced. the record disk 3 is placed upon the racing disk 2, and this then placed in position on the turn-plate l. The conveyor-spindle unit is then fitted by means of the sleeve H to the projecting end of the main driving 5 shaft of the gramophone which is firmly gripped by the action of the helical spring l4. On the other hand, the distancing piece 8 is attached to the sound-box arm 5 by means of the strap I. The distancing piece and the conveyor spindle 10 unit are then coupled together by means of the guide rod 9, by screwing the one end of the latter to the distancing piece 8 and placing the nut l0 in position on the spindle l I.

The provision of the distancing piece 8 ensures lo the applicability of the device irrespective of the shape and curvature of the sound-box arm. Thus, Fig. 1 shows a bent arm with an acoustic sound-box, and Fig. 2 a straight arm with an electric sound-box.

Further, the articulate guide rod 9 likewise permits oi the universal application of the device according to the invention, irrespective of the height of the sound-box, since it permits of keeping the flying spindle ll always in a horizontal position.

With disc records there is the danger of warping and buckling. This drawback is overcome, in accordance with the invention, by pressing the thin record disc upon its base, either at the outer edge or at the centre, by means of a ring or disk I of metal.

A form of construction embodying this feature is shown in Fig. 4.

If the record disc itself be provided on the under side with a rough coating or with studsor the like engaging elements, it becomes unnecessary to provide a separate facing disk, and the tum-plate can be furnished with the necessary counter engaging elements.-

40 One of the conditions that must be iulfllled ii a satisfactory record is to be obtained is that the cutting'taken by the style needle be of the same thickness throughout, that is to say that the sound groove out should be of exactly the same depth throughout. In order to make it easier for the novice to observe this. requirement, and to provide a visible check on its'iulfllment, the invention further provides for the use of record discs made up of layers of difierent colors. To a roundation disk for example of red color there are applied one or more delimited or merging, difierently colored layers. Assuming the proper thickness of the cutting to be for example just down to the red color, the bottom of the groove should always be of this color. It the bottom of the groove appears pink or if red parts appear in the cutting it will be seen at once that the groove is too shallow or too deep, respectively. The load on the cutting needle must then be altered or the turn-plate set to run accurately in one plane. In

any case the user is at once warned that the conditions are not right for obtaining satisfactory recording. Since, as is well known, the cutting runs inwards it is easy to keep the same under 5 observation, the more so since when studs are employed which project above the surface of the record disk the cutting becomes wound around these studs as on a reel.

'I claim: v

1. An arrangement for cutting sound records by the employment of an ordinary talking machine with turntable, comprising in combination a bearing, means on said bearing for securing it to the centre pin of the turntable of the talking machine, a screw threaded guide spindle supported in said bearing with one of its ends only, a nut riding on said guide spindle, connecting means pivoted to said nut, an intermediate member adjustably secured to said connecting means, and means on said intermediate member for its removable attachment to the supporting arm oi! the sound box of a talking machine.

2. An arrangement for cutting sound records by the employment of an ordinary talking machine with tumtable'comprising inv combination a bearing, means on said bearing for securing it to the centre pin oi the turntable of the talking machine, a screw-threaded guide spindle supported in said bearing with one of its ends only, a nut riding on said guide spindle, articulated connecting means pivoted to said nut, an intermediate member adjustably secured to said connecting means, and means on. said intermediate member for its removable attachment to the supporting arm oi the sound box of a talking machine.

3. An arrangement for cutting sound records by the employment oi an ordinary talking machine with turntable comprising in combination a slotted sleeve adapted to be placed on the centre pm of the turntable or the talking machine, a helical spring wound round said sleeve for pressing the sleeve into gripping engagement with said centre pin, a screw-threaded guide spindle supported in said bearing with one of its ends only, a nut riding onsaid guide spindle, connecting means pivoted to said nut, an intermediate member adiustably secured to said connecting means, and means on said intermediate member for its removable attachment to the'supporting arm of the sound box of a talking machine.

4. An arrangement for cutting sound records by the employment of an ordinary talking machine with turntable, comprising in combination a slotted sleeve adapted to be placed on the centre pin of the turntable, a stud projecting from said turntable, a helical spring wound round said sleeve for pressing the sleeve into grippin engagement with said centre pin, one end of said spring being secured to said sleeve and the other end of the spring being attached to said stud, a screw-threaded guide spindle supported in said bearing with one or its ends only, a nut riding on said guide spindle, connecting means pivoted to said nut, an intermediate member adjustably secured to said connecting means. and means on said intermediate member for its removable attachment to the supporting arm of the sound box of a talking machine.

O'I'IO ZICHA.

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