US1251828A - Sound-box adjustment for talking-machines. - Google Patents

Description

L. K SCOTFORD. v s0uN0 BOX Amusmzm F R TALKIN M H APPLICATION FILED OCT. 26. 1916.

24 26 a7 24 A v I j y I veigllv LOUIS K. SCOTFORD, OF CHICAGO, ILLINOIS.

SOUND-BOX. ADJ Il'STMEN'I FOR TALKING-MACHINES.

Specification ofletters Patent.

Patented J an. 1, 1918.

Application filed October 26, 1916. Serial No. 127,914.

To all whom it may 00n0e7'n:

Be it known that I, LOUIS K. Soo'rrom), a citizen of the United States, residing at Chlcago, in the county of Cook and State of namely, the vertically undulating or hilland-dale and the laterally undulating or' zig-zag types. For reproducing sounds with the vertically undulating type, it is essential that the diaphragm of the sound box be disposed in a plane extending'across or transversely to the longitudinal axis of the tone-arm so that the vertical undulations on the record disk will cause a movement of the stylus lever in a substantially vertical plane and a consequent movement of the diaphragm; where the grooves of the records are of the laterally undulating or zigzag. type, it is desirable that the diaphragm of the sound box be disposed in a plane extending substantially parallel to the longitudinal axis of the tone-arm and preferably in a vertical direction so that the lateral vibra tion of the stylus or needle will cause corresponding lateral vibrations of the diaphragm. It will be seen therefore that in order to reproduce sounds from these two types of records, the talking machines must differ in construction or they must be provided with adjustable means, whereby the sound box may be adjusted to suit the record being used. An attempt has been made heretofore to solve this difliculty by making the sound box adjustable on the tone-arm,

- but such attempts have not met with success for the reason that when the sound box is moved from one position to another, the stylus has been varied in its spaced relation to the pivotal axis of the tone-arm, so that in one of the two positions of the sound box.

the stylus is located at such a distance from the pivotal axis of the tone-arm that it cannot travel across the disk or record in the path most suitable for a perfect reproduction of the sounds, and most suitable for relleving the stress upon thestylus when the machine is in operation. In order to reduce the stresses upon the stylus or needle, other than those; produced by the recorded undulations of the record or disk such as are adapted to produce the vibrations which effect the reproduction of sound, it is desirable that the point of the stylus move in an are or path extendin across the disk or record through the axis of rotation thereof, so that.

the stylus is subjected at all times merely to the action of the undulations which constitute the record of the sounds, and not to any lateral stresses set-up by the edges of the grooves on the disk or other influences, which might set up other vibrations which would interfere with the proper reproduction of the recorded composition.

The principal object of the present invention is to provide an improved talking ma chine comprising means for adjusting the sound box and stylus to either of two operative positions, in either of which the point of the stylus is the same distance from the pivotal axis of the tone-arm about which the tone-arm moves as the stylus moves across the record. Another object '1 to provide means for adjusting the sound box in different positions on the tone-arm so that the diaphragm thereof may be disposed in the proper position for either of the two types of records above mentioned, and to provide means for effecting this adjustment while 'ma1nta1n1ng the stylus or needle and the bore of the needle holder coincident with the axis of the end of the tone-arm to which the sound box and parts carried thereby are attached. Still another object is to provide a sound box and tone-arm having a detachable coupling for connecting the same, whereby the sound box may be adjusted to either of two operative positions, in either of which the stylus will be coincident with the axis of the coupling by which the soundbox is connected to the tone-arm. A further object is to provldean improved adjustable sound box carrying a stylus which will be 10- cated at all times in a plane containing the pivotal axis of the tone-arm. A further object is to provide a tone-arm having a tubular extension telescopically engaging the same and connected to the soup d. box, whereby the telescoping parts may be disengaged to move the sound box from one to the other of two operative-positions of the same with specification taken in connection with the box and tone-arm When accompanying drawings, in which one embodimentof the invention is illustrated.

In the drawings-* Figure 1 shows a side elevation of a tone arm and sound box embodying the features of my invention, the sound box being in the position required for the reproduction of sounds from a record of the vertically undulating type.

Fig. 2 is a side elevation of the construction shown in Fig. 1 after the sound box has been moved to a positlon adapted to a reproduction of sounds from a record having grooves of the laterally undulating type.

Fig. 3 is a perspective view of the tele' scoping parts which form the detachable coupling, by means of which the sound box is adjusted in its relation to the tone-arm.

Fig. 4 shows an end elevation of the sound adjusted as shown in Fig. 1; and

Fig. 5 shows an end .elevation of the sound box and tone-arm when adjusted as shown in Fig. 2.

In the drawings the numeral 10 designates the tone-arm of a sound reproducing instrument, havin the enlarged transversely disposed end 10 1: ereof pivotally mounted in a suitable bearing 11 to swing about the pivotal axis 12, and having .adjacent the.

smaller end thereof an angularly disposed tubular part 13. The tone-arm is provided with a tubular extension 14, which is con- 4 nected at its lower or outer end to the sound box 15, and which is adapted to have a telescoping engagement at its upper end with the angularly'disposed part 13 of the tonearm. The lower extremity of the part 13 is thickened to form a rim or 'fiange 16, adapted to pass around the outside of the ex-.

tension 14 to-form a relatively tight frictional engagement therewith, the end of the extension 14 being adapted to engage the an nular shoulder 16 within the flange 16. This flange 16 is provided with two longitudinal slots 17 Which are disposed substantially 90 apart and which extend upwardly from. the end of the flange to receive the clamping thumb screw 18, which has a threaded engagement with the extremity of the extension .14, and which is adapted to pass into one of the slots 17 when the extension 14 is passed into a telescoping engagethe tone arm. The relative location of the slots 17 and of the sound box 15 on the extension 14 of thetonc-arm, is such that when the clamping screw 18 is engaging one of the slots, the diaphragm 19 of the sound box will be disposed in a plane extending across the longitudinal axis of the tone-arm; while, when the screw 18 is engaging the other of the slots 17, the diaphragm 19 will lie in an upwardly directed plane substantially parallel to the longitudinal axis of the tonearm.

The diaphragm of the sound box is actuated by and operatively connected to the stylus arm or lever 20, which comprises a hub 21 pivotally mounted between the lugs or flanges 22, 'inojecting downwardly from the sound box, by means of the bearing pins or screws 23. The hub 21 carries the needle holder 24 having a bore adapted to receive the needle or stylus 25 which may be held in fixed adjusted position in the needle holder by means of the locking nut 26 and which bears upon the record disk 27. These parts are so located and constructed that the bore of the needle holder 24 is disposed at an angle to the plane of the sound box and the diaphragm and lies in a plane con- I taining the arm 20 of the stylus lever. The plane of the diaphragm is also inclined to the axis 28 of the part 13 of the tone-arm. These parts are further so proportioned and arranged that when the sound box is in either of the two positions illustrated in Figs. 1 and 2, the bore of the needle holder and the needle or stylus carried thereby will be coincident with the axis 28 of the telescoping parts 12 and 13, which form the detachable coupling, by means of which the adjustment of the sound box on the tonearm is permitted. It will also be apparent that in either position of the sound box the point of the needle 25, which coacts with the record 27, will be the same distance from the vertical pivotal axis 12 of the tone-arm,

.about which axis the tone arm moves as the stylus travels over the record during the operation of the sound reproducing machine, and that the needle and needle holder will always lie in a plane containing the pivotal axis 12 of the tone arm.

In the operation of this improvement, the sound box may be adjusted with respect to the tone-arm in order to p ovide the proper fixed relation for use with the particular kind of record being used. In either position of the sound box and stylus or needle, the axis of the needle will be coincident'with the axis of the tubular extension 1e and angularly disposed part 13, and the point of the needle will be at a constant distance from and in a plane containing the pivotal axis 12 of the tone-arm, so that if'the parts are suitably proportioned and located in the initial construction, the point of the needle will always travel across the record in a path passing substantially through the center of the record regardless of the kind of record being used.

Although I have shown and described a particular form of the invention for purposes of illustration, it will be understood that itgmay be embodied in various other forms without departing from the spirit of the invention as defined in the appended claims.

What I claim is:

1. In a talking machine, a tone-arm having a tubular extension, a sound box connected to said tubular extension and containing va diaphragm, a co'upling for permitting said sound box to be movedto either of two operative positions with respect to the tone-arm, the plane of said diaphragm being inclined with respect to the axis of said tubular extension, a needle holder having a bore to receive a needle, said bore I phragm.

2. In a talking machine, a tone-armhaving a tubular extension, a sound box having a diaphragm-therein inclined with respect to the axis of saidtubular extension, at tuj bular member attached to said sound box,

said tubular member and said tubular'extension on the tone-afmhaving a telescopic engagement, one of said last "mentioned members being provided ,with two slots 'extending substantially l n'gitudinallyof said tubular member, a clailiiping membercarried by theother of said embers and adapted to engage eitherof said slots, thereby per-' I mitting said tubular member to be removed from saidtubular extension and replaced thereon with said clamping member engaging either of said slots, a needle holder hav- 1n be ng inclined with respect to the plane of a bore to receive a needle, said bore said diaphragm and alining'with the axis of said tubular extension in both positions of the sound box, and means for operatively connecting said needle holder and diaphragm.

In testimony whereof I have subscribedmy name.

Images