US2614848A - Phonograph needle - Google Patents

Description

fiwwzz arazdd 177/(efzevz5g dffawm/ae (a.

esley w E KIDD ETAL PHONOGRAPH NEEDLE F led Oct s 1947 Oct. 21, 1952 Patented Oct. 21, i952 fl'HO NOGRAPH NEEDLE Wesley E. Kidd and Robert L. Metz'enberg, cm-

cago, Ill., assignors to Sears; Roebuck and 00., Chicago, 111., a corporation of New York Application Qctober 6, 1947, Serial No. 778,102

It is well known that in the audible reproduc-.

tion of sound recordings through the medium f a tone arm pickup device, incidental noise characteristics in the sound groove as wellas other extraneous sound disturbances are sometimes superimposed onto the recorded sound transmission frequencies. Among such are vibrational resonance efiects usually accompanying high frequency notes as well as scratch noises usually audible with lower notes or soft note combinations. The overall result of such disturbances is to distract from the pure tonal qualities of music and to impart harsh mechanical sound characteristics, as a result of which musical reproductions or recordings are often too manifestly distinguishable from original music or voice.

Various devices have been tried to overcome these and other mechanical or foreign sound characteristics which accompany .the reproduc tion of subject matterrecorded and such have included a wide range or application incident to the electrical and mechanical features of sound reproducing apparatus. The present invention concerns itself with improvements toward inhibiting the transmission of mechanical reproduction noises through the medium of damping them out at the initial sensing element, the sound track coursing needle.

Towards this end there is proposed herewith an. improved type of phonograph needle characterized .by the provision of a graduated taper throughout its shank portioncoupled .jwith a significant angular offset or displacement near the lower region of the shank and having located within the displace portion or neck of the needle a series of parallel disc damping vanes equally spaced one from the other and of identical circular pattern. The location of these discs has been determined experimentally in relation to the other structural characteristics of the needle whereby their efiect is to damp out recording scratches, vibrational overtones, and secondary tonal effects and to materially eliminate or reduce these effects until they are inaudible to human perception. The way in which this phenomenon is believed to be ac- 2 Claims. (01. 274-48) complis-hed through the medium of the aforementioned damping discs is an effect in the nature of countering the vibrational sound disturbances by reflecting against the side of the vanes cancelling out frequencies of similar wave characteristics.

For a more comprehensive understanding of the present invention reference will now be had to the accompanying drawing and to the following detailed specification in which like reference characters designate corresponding parts throughout and in which: a

Fig. l is a side elevation of a portion of a horizontal turntable mounted for vertical axis rotation having a tone arm pickup which carries a needle designed according to the present invention,

Fig. 2 is an enlarged side elevational view of the needle featured in Fig. 1 showing the pickup head in dotted phantom, Fig. 3 is an enlarged transverse sectional view taken approximately on line 3-3 of Fig. 2, and Fig. is a furtherenlarged transverse sectional view through the jewel point needle socket extremity indicating the needle surface curvature and its manner of securement.

Attention is now directed more specifically to Fig. 1 wherein the reference numeral H designates a base within which there may be housed any of various types of turntable rotating'mechanism. Through this base there protrudes a vertical spindle l2 which may beof considerable length, as in the case of well known types of multiple record playing apparatus, or of shorter length in the case of single operation apparatus. Carried by the spindle l2, usually in splined close fitting alignment, is a turntable collar 13 integrally associated with the turntable disc 14, the surface [5 of which is covered by a felted fabric so as to insure against marring or scratching of the record disc it placed thereon for sound reproduction. r

The turntable rotates in a clockwise direction as viewed in plan so that the flange I! will be passing from right to left as viewed in Fig. l, the spiral cutting in the surface of the recording disc I6 is accordingly an involute approaching the center during clockwise tracking of its course.

The pickup arm I8 is customarily supported on a horizontal pivot, weighted and balanced preferably so as to bear with its needle end at a slight preponderance of weight ranging from one and one-half to six ounces by reason of which the extremity of the needle 2| is made to follow in the sound groove of the disc IS. The element within which the anchor shank 22 of the needle 2| is carried is preferably one which is possessed of sound transmitting characteristics between its point of engagement with the needle shank 22 and its point of communication with an amplifier device either mechanical or electrical. I

The needle receptacle or anchoring media is customarily provided with a tightening screw 23 to integrate the two elements in a sound transmission sense. The angle of inclination of the shank 22 as manifested in Figs. 2 and4 is 'the conventional angle and is the same as that of the jewel carrying socket extremity 24. mediate the shank portion 22 and socket 24 is a special type of damping beam 25 formed as an integral portion with the shank 2| and neck 24 and constituted principally of a continuation of th taper which begins at approximately the point 26 of the shank and which continuesat a very gradual rate of slope to the extremity of the needle. Thedamping beam 25 merges with the shank 2| at an angle of curvature approximately similar to that at which the same beam merges with the point extremity 24 but near the center, longitudinally speaking, of the beam 25 there are formed three identical spaced disc flanges indicated 26, 21, and 28. The adjacent sides of the discs 26 through 28 are preferably parallel or as nearly so as manufacturing methods will permit, so that certain sound frequencies striking the sides of the discs will rebound at the same frequency cancelling out the initial eii'ectsand resulting in a muting or scratch sound inhibiting characteristic.

These flanges are equally spaced one from the other as best shown in Fig.2, The edges of said discs are preferably flattened as at 29. These damping vanes 26 to 28 not only serve the functional purpose of damping vibration and casual noises from being transmitted ;at an audible amplitude through the shank .of the needle 2| but also as an alignment of identical height protruding engagement elements these flanges afford a means whereby the needle may be more effectively grasped, held, and placed for critical adlustment in the tone arm needle socket.

In conjunction with the aforedescribed damping implementation, it has been found expedient and economically advantageous to provide this type of needle with a permanent jewel hard extremity. Accordingly the end of the needle is drilled as at 3| and thereinto is placed a shaped sapphire point 32, retention being effected by cementation, and the point being profiled in correspondence with intersecting asymptotes, the effect of which has been found to contribute towards a lesser Wearing of the side surfaces of recording grooves consistent with a more faithful response to the sound characteristics.

While the present invention has been explained Inter 4 and described with reference to a specific embodiment, it is to be understood nevertheless that numerous modifications and variations may be incorporated without departing from the essential spirit or scope thereof. It is accordingly not intended that the breadth of the invention be construed in terms of the specific disclosure of the accompanying drawings'fnor by the words of the foregoing detailed description; but instead to be accorded a latitude of interpretation as indicated by the hereunto appended claims.

The invention claimed is:

l. A phonograph needle comprising, a principal shaft tapering progressively smaller from a securement shank portion diameter to a sensing but in different planes, an intermediate portion Number of said shaft having substantially identical angularity with said shank portion and with said point portion, and a series of substantially parallel damping vanes integral with and perpendicular to the axial center of said intermediate portion. 2. An oiiset type phonograph needle which comprises, a shank shaped as-a tapering cylindrical metal rod bent into three portions of which a first or securing portion is of largest diameter, a second or vane-supporting portion is of progressively diminishing diameter ranging from the diameter -ofsaid first portion, and of which a third is of further progressively smaller di ameter ranging from that of said second portion, said first and thirdportions being substantially parallel to each other, and said second portion forming an angle with respect to said first-and third portions, "and a plurality of-similar damping vanes secured to said second portion having flat sides parallel to each other and spaced from one another whereby there is produced a sound damping effect limited to scratch noise levels of sound frequency.

E. Kinn, ROBERT L. METZENBERG.

REFERENCES CITED The following references are of record in the file of this patent: i

UNITED. STATES PA'I'ENT'S liame Date 1,039,208 ,Steinert Sept. 24,1912 1,084,573 Claussen Jan. 13, 1914 2328. 8 Capps Sept. "7, 1 4 2,342,813 Mason s Feb. z9,, 944 2,495,934 Kondrath Jan. 31, 1950,

FOREIGN PATENTS Number Country Date 8,562 Great Britain Apr. 8, 1999 202,493 Great Britain Aug. 23, 1923 350,887

Great Britain June 18. 1931

Images