US2164199A - Phonograph style - Google Patents

Description

t a :1 June 27, 1939. J, JR 2,164,199

PRONOGRAPH STYLE Filed June 9, 1937 Patented June 2-7, 1939 UNITED STATES PATENT. orrica ZClaims.

'l'his invention relates to an improved style or needle for use with sound-reproducing instruments such as phonographs and the like.

One object of the invention is to provide a needle of the type indicated which will play a large number of records without distortion in the sound reproduced thereby.

Another object of the invention is to provide a needle of the type indicated which will play a large number of records without abrading or scoring the records to cause distortion of the sound reproduced thereby.

Another object of the invention is to provide a novel form of style or needle which will follow bearing against the upper edges thereof or on the top. of the record to cause wear thereon.

Another object of the invention is to provide a one-piece style or needle of the type indicated having a substantially flat-sided, pointed end of a thickness to fit the groove in the record in such manner as to prevent wearing shoulders on the needle.

Another object of the invention is to provide a style or needle having its record-engagng portion of concave-convex shape in cross-section formed to the mean radius of the record groove to adapt the needle to traverse the latter without scratching or scoring and providing for a more sensitive response to the undulations of the sound-track.

Further objects of the improvement are set forth in the following specification which describes a preferred form of construction of the style or needle as illustrated in the accompanying drawing. In the drawing:

Fig. 1 is an elevational view of the sound-box of a conventional type of phonograph showing the present improved needle applied to the socket thereof with its point engaging the soundtrack of a record-on the turntable of the phonor ph;

Fig. 2 is an enlarged transverse sectional view of the sound-box support or socket for the needle taken on line 2-4 of Fig. 1 and showing the needle in place therein with its point engaging the sound-track of the record, also illustrated in section;

Fig. 3 is a fragmentary plan view of the record shown as greatly enlarged and illustrating the concavo-convex shape of the pointed blade of the needle'in section on line 3-3 of Fig. 2;.

Fig. 4 is a greatly enlarged view of the improved needle showing the flat-sided blade at its point; and

Fig. 5 is a similar view looking towards the thin edge of the flat blade of the needle.

The commonly used style or needle for phonographs and like sound-reproducing instruments is formed of cylindrical steel .rod or wire tapered the sound-track or groove of the record withoutto apoint at one end to adapt it to enter the groove orsound-track of the record. The life of such a form of needle is very short, it being advisable to discard and replace the needle after the playing of each record in order not to spoil the record by the abrasive action of the needle thereon. Considerable friction is engendered during the traverse of the needle in the soundtrack and as the material of the record is relatively hard and flinty it causes abnormal wear.

on the sides of the point of the needle. That is to say, the point is worn down on its sides which causes the formation of shoulders and these shoulders bear against'and scrape the top of the record to cause damage thereto. Moreover, the shoulders eventually prevent the point of the needle from bottoming in the sound-track orv groove of the record and therefore accurate and true-toned reproduction is impossible with such a worn needle.

The present invention has for one of its objects to provide a needle not subject to wear and the forming of shoulders on its sides liable to abrade and scratch the top of the record. To accomplish this result the point of the needle is flatted on opposite sides or, preferably, made substantially flat with a concavo-convex shape in cross-section as later more fully explained. My improved needle is thus rendered capable of playing more than a hundredrecords without being worn away on the sides of its point to form shoulders liable to damage the record or to interfere with the proper reproduction of the sound. The present improved needle is therefore well adapted for use in phonographs having automatic record-changing mechanisms as it can be used repeatedly for more than a hundred records without replacement as is necessary with most types of needles. Heretofore, automatic record-changing instruments have usually required the use of a special form of needle having a tip of harder metal or, in some cases, a jewel point to resist wear during its use. Such a type of needle is expensive to manufacture while my present improved needle is relatively cheap to produce and has practically all the advantages of the hard-tipped needle.

Referring first to Fig. l of the accompanying drawing, 2 designates the sound-box at the end of the tone-arm 3 of a conventional type of phonograph comprising the usual rotary turntable l. The rector, designated R, rests on the turntable 4 and the needle 5 is shown as held in a socket 6 on the sound-box 2 by means of the usual thumbscrew 1, see also Fig. 2.

Referring to Figs. 4 and 5, the present improved needle comprises a body portion III of substantially cylindrical shape adapted to seat in the hollow of the sound-box socket 6 and to be clamped in place by the end of the set-screw I terminating in the point i2. At a distance downwardly from the joinder of the shank with the tapered portion ii the needle is ground or otherwise flatted on its sides to form a relatively thin tapered blade it. Preferably, instead oi grinding or forming the sides oi the point in flat planes the blade H is shaped to concavo-convex form in cross-section, as shown in Fig. 3, on a radius corresponding substantially to' the mean radius of the sound-track on the record with which it is to be used. The purpose of this concavo-convex formation of the pointed end oi" the needle is to provide that it will conform substan tially to the curvature of the sound-track which it traverses during the rotation of the record.

It will be noted by reference to Fig. 5 01' the drawing that the two opposite sides of the fiatted or concavo-convex shaped blade it of the needle are parallel. The blade H is made on! slightly less thickness than the width of the groove or sound-track, indicated at t in Figs. 2

and 3, so that the needle may have a slight clearwith the flatted sides of its blade-portion ill 8X- tending longitudinally of the sound track or groove 1 in the record, see Figs. 1, 2 and needle is clamped in place by screwing the thumb-screw against its side and, preferably, the

body or cylindrical portion i 0 of the needle isflat ted oi! on its side corresponding to one of the fiatted sides of its blade-portion i 4 to insure that it is properly placed in the sound-box socket.

The point of the needle is placed in the soundtrack t of the record R and as the latter is rotated with the turntable 4 the needle will traverse the sound-track or groove t with a smooth undulatory motion without any tendency to scrape the of the groove or to impinge against the upper edges thereof. That is to-say, theblacleportion. it of the needle will conform substantially to the curvature e sound-traclr or groove t to travel smoo 3 therein without scratching or abrading the. walls of the groove. Moreover. as the tip I2 oi the needle point wears down the blade-portion H of the needle simply sink deeper into thegroove t of the record without contacting the upper edges of the wells of the groove. In this way the point of the neo die is relieved of any wear tending to form shoulders on its sides and consequently it will always bottom in I the groove even after considerable wear on its point. By preventing the formation of shoulders on the sides of the needle the upper edges oi the groove in the record are saved from abrasive action and consequently the record will not be damaged by repeated use oi? the same as is the case when needles of the type corn- .ily used are employed for playing more than one record. It will thus be seen that the present improved needle may be used repeatedly in the phonograph or other sound-reproducing iml rument without deterioration. and without The' reproduction and without abrasive action or wear 7 on the record.

As another important feature of improvement in the present needle it will be noted that the frusto-conical or tapered portion ii which erztends between its main body ill and the blade to is of substantial structure to prevent undue vi bration in that part of the needle which projects below the socket S of the sound-box. In other words, the blade-portion ll of the needle is relatively short as compared with the length oi its supporting portion ii and this latter portion has the effect to stiffen the point of the needle to prevent vibrations which would distort the sound being reproduced.

From the foregoing it will be observed that the present invention provides an improved. form of style or needle for phonograph; and lilre soundreproducing instruments which 'is much more durable in use than common types of needles heretofore used; which may be used repeatedly without undue wear or injury to the record; and the use of which results in more perfect, tone reproduction from the record being played.

While the improved style or needle is herein shown in a preferred form of construction, it is to be understood that slight changes may be made in its shape and proportions without departing from the spirit or scope of the invention. Therefore, without limiting myself in this respect, I claim:

1; A phonograph styleor needle for cooperation with records having hili-and-dale sound track grooves, saidneedle constructed with a body portion oi cylindrical form and a portion extend,

ing downwardly therefrom and gradually tapered to a point, a considerable proportion of the length of said tapered extension being cut away on its sides to form a relatively thin blade, said blade being of somewhat less thickness than the width oi the groove in the record with which it is used to adapt it to fit between the sides of the groove with a slight clearance and of a length greater than the depth oi the groove to adapt its pointed end tobottom therein, one side of the blade portion being concave and the other side being convex on a radius conforming substantially to the mean radius of the groove in the record.

2. A phonograph style or needle for cooperation with records having hill-and-dale sound tracl: grooves, said needle consisting in a cylindrical body-portion continued downwardly in an extension tapering gradually to a point with a considerable proportion oi the length of the tapered extension cut away on its sides to provide a thin blade with substantially flat parallel faces, said. blade being of a length greater than the depth of the sound grooves in the record to adapt its pointed end to bottom thereinwith its sides conforming to the sides of the groove, and the body portion oi the needle having a flat iace parallel with the flat sides of the blade to adapt it to be engaged by the set-screw in the socket oi the sound-Too to hold the flat sides of the blade in position parallel with sides of the sound traclr K groove oi the record whereof the needle may travel smoothly therein with its point engaging; the bottom of groove.

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