US1739201A - Phonograph needle - Google Patents

Description

Dec. 10,v 1929. c. A. AHLsTRoM PHONOGRPH NEEDLE Filed Jan. 31, 1928 Patented Dec. 10, 1929 UNITED STATES' PATENT OFFICE rHoNoGaAPH NEEDLE Original application med December 9, 1925, Serial No. 74,345. Divided and this application led January 31, 1928.

and the primary object'thereof is to provide a needle which eliminates static and surfaces noises resultant from any ofthe metallic parts, or contact of the needle or stylus tip with the record, or disturbances of atmospheric, magnetic or mechanical origin.

A further object of the invention is to provide a needle which eliminates metallic vibrations and the static shock that effects distortion of the sound being reproduced and which also clarifies and isolates 'indiy vidual voices and accompaniment instruments.

Still further the invention aims to amplify or increase the sound to its natural volume and quality and to preserve the natural purity thereof.

The invention has still further and other objects which will be later set forth and manifested in the course of the following description.

In the drawings Fig. 1 is a side elevation of a reproducer with the present invention applied thereto;

Fig. 2 is a section on line 2 2 of Fig. 1;

Fig. 3 is a side edge elevation of the nee-v dle, with a static shock and surface noise absorbing device in section;

Fig. 4 is a front elevation of Fig. 3 and Fig. 5 is a section on line 5 5 of Fig. 1.

As disclosed in my aforesaid application, the sound box or reproducer 1 has the usual diaphragm V2 to which the stylus bar 3 is secured at its inner end. This stylus bar is thinned or flattened at its central portion as indicated at 4. The outer end of the stylus bar is securedto the -stylus plate 5 that engages theV pivot points 6.

The needle 7 as shown in Figs. 3 and 4 has a thinned and curved portion 8 so as to provide a flexible undulating shock absorbing tip, which bears upon the record R as depicted in Fig. 1 of the drawings, and wherein it will be noted that the concave side.of the concavo-(nexjthinned part 8 Serial No. 250,815.

directly faces the record so as to resiliently support'the sound box from the record.

As depicted in Figs. 2, 3, 4 and 5, a static shock and surface noise absorbing device is provided consisting of a metal U-sha ed clip or clamp 15 having tubular rub er pieces 16 covering the arms of the clamp. The shock and surface noise absorber is applied to the thinned central part 8 of the stylus bar and a similar device is applied to the curved and rounded needle tip, shown in Fig. 3.

The present invention therefore substitutes for 'the round, rigid needle, a flexible needle having a rounded sharp tip 8 with its lower po tion directly above the rounded point expan ed and flattened very-'thin in atransverse parallel line with the face of vthe record, to create a flexibility when used for sound reproduction, the expanded flattened portion having an un lulating form,

' with its rounded sharp tip 8 curved slightly downward toward the record for engaging every minute indentation inthe record, and for reproducing every inflection in the sound as erfectly and as naturally as it exists in.t e record.

-The stylus bar and .the rigid shank of the needle as depicted in Fig. .1, are disposed at approximately 45 to the plane of the record, while the record engaging tip of the needel is disposed at approximately to the plane of the record, so that the said tip is approximately at 15 to the axis of the Shank of the needle.

With the above construction, the needle is absolutely resistent to movement laterally of the groove, while still permitted to yield or flex in a plane which is at right angles to the plane of the record. With this confined movement, distortion of the sound resultant from the shock of the present day ri `d needle is eliminated.

y virtue of applicants structure of needle, whereinJs'ame' can yield at right angles to the plane of the record, a quicker and truer response to the laterals is had. Otherwise expressed, the needle is free to respond to the laterals and follow the groove more perfectly, thus obtaining true reproduction.

From the foregoing it will be seen that the present invention involves a needle which has a straight and rigid shank, one end of the shank being thinned to provide a flexible part terminating in a. record engaging tip, the thinned part having a compound curvature throughout its length so as to dispose the ti pv substantially more perpendicularly to the plane of the reeord, It Ais essential that the shank be rigid and straight so as to confine the flexibility to the end portion only of needle. It is also essential in reproduction, according to the present invention, that the flexibility of the record engaging tip he in the direction of the groove and not laterally .of the groove.

The stylus bar having a thin, expanded s central section counteracts the stalc shock and interfering sounds from being repre duced throu h the diaphragm, that have not been fully a rbed by the exible undulating portion of the needle or stylus The static shock and surfface noise abs'bing clamp .attached to 1the 'thin central seetion of t e stylus 'bar and to the stylus tip absorbs and arrests static shocks and metallic vibrations and surface noise emanating from the needle tip in its travel in the groove of the necord, and pmvents auch interfering sounds from being ifeproduced' through the y diaphragm.

To facilitate .the adaptability of the needle to the various forms of reprodurs to zonorm to any particular 'angle of the st s vbar with the plane oftheseoond, the straight shank of the needle caribe placed at any 'ven angle to dispose -the tip of the needle ou the record at approximately 60 to the plane of the record. o

lVhat is claimed is l. A needle for use with a stylus bar .and phonograph record, composed of a straight rigid shank 'having a thinned end of approximately uniform thickness to pnovide a. flexible part which latter terminates in an integral record engaging tip portion, said thinned part being of gradual compound curvature throughout its length and formed to extend toward the record and with the axis of the tip portion at substantially i60-deto the Yplane of the record 2. A needle for use with a stylus bar and phonograph record, composed ni a straight rigid shank having ,a thinned :end of apnfoximately uniform thickne to provide 'a (lexmately uniform thickness to provide a iiexible part which latter terminates in an integral record engaging tip portion, said thinned part being of gradual compound curvature throu hout its length, and means to support the lank from the stylus bar so as to dispose the axis of the ,tipI portion at approximately 60 degrees to the plane of the repond.

In testimony whereof affix my si nature.

CHARLES A. AHLST OM.

ible part which hitter terminates :in an iu` iegral record ,engaging tip portion, said thinned part being :of gradual com Y curva-tune throughput its length and fomed to extend toward the -reeold and having the axis of its said tip-portion at approximately L5 'degrees to fthe axis ef :the shank.

f3. A needie'foruse with astylus bar and ,phenagraph record, composed of a straight rigid Shank hating a thinned and of approxi-

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