US2553822A - Phonograph needle - Google Patents

Description

May 22, 1951 F. c. HLTZ, JR 2,553,822

PHoNoGRAPH NEEDLE Filed April lO, 1948 Patented May 22, 1951 PHONOGRAPH NEEDLE Frederick C. Holtz, Jr., Wadsworth, Ill., assignor to Pfanstiehl Chemical Company, a, corporation of Illinois Application April 10, 1948, Serial No. 20,327

7 Claims.

This invention relates to a phonograph needle, and more particularly to a phonograph needle having a tip portion offset from the shank of the needle.

One feature of this invention is that it provides an improved phonograph needle; another feature of this invention is that it provides a phonograph needle having improved vertical compliance; a further feature of this invention is that it provides a phonograph needle having compliance in the direction of all forces encountered during operation; still another feature of this invention is that it provides a phonograph needle having a ,protective device which guards the needle and the record against damage without increasing the mass or inertia of the needle or tone arm; yet a further feature of this invention is that it provides a phonograph needle having a tip portion extending below the shank of the needle and spaced from a projection of the-axis of said shank; and yet another feature of this invention is that it provides a phonograph needle having a resilient member in the form of an open ended loop, one end of which terminates in a tip Dortion which extends below the end of the shank of the needle outside but closely adjacent the periphery of a projection of the end face of said shank so that the tip of the needle and the end face of the shank retain substantially the same positions relative to the surface of the record regardless of the height of the surface of the record with respect to the pivotally mounted base of the tone arm.

Other features and advantages of this invention will be apparent from the following specification and from the drawings in which:

Fig. 1 is a fragmentary side elevation of a tone arm carrying a. needle constructed in accordance With the invention, the tip of said needle engaging the surface of a record;

Fig 2 is an enlarged side elevation of the needle of Fig. 1 removed from the tone arm;

Fig. 3 is a bottom plan view of the needle shown in Fig. 2;

Fig. 4 is a fragmentary elevation of a modified form of needle;

Fig. 5 is a bottom plan view of the needle shown in Fig. 4;

Fig. 6 is a fragmentary side elevation similar to Fig. 4, but of still another modified form of needle; and

Fig. '7 is a bottom plan View of the needle of Fig. 6.

In the reproduction of sound from a phonograph record, particularly from a laterally cut record in which the undulations representing the sound to be reproduced project into the record groove from the side walls thereof, a needle having compliance or yieldability in a vertical direction (speaking of the parts in the position in which they are illustrated in the drawings and in the position which they conventionally assume during operation) will eliminate much of the undesirable scratching which is ordinarily transmitted through the amplifying and transducing apparatus of a phonograph which employs a rigid needle. 1n addition, a needle having such compliance will also lessen so-called needle talk and other surface noises which reach the ear directly from the needle without being transmitted through the amplifying system associated with the phonograph. To achieve compliance in a vertical direction the needle which carries vibrations from the record to the crystal or other translating device must have a iiexible portion which is thin compared to its length in a plane substantially parallel to thel planeof the record surface. In order to protect such a needle from deformation or breakage it is desirable that the needle be guarded so that in the event the tone arm is dropped too hard the flexible portion of the needle will not be bent beyond its limit of elasticity. In the past this has been accomplished by incorporating a separate guard device as a part of the pickup structure, or by adding an extending foot to the needle shank, the end of the foot extending from the shank and terminating closely adjacent the record engaging tip of the needle. This arrangement adds eXtra mass and inertia to the needle so that the needle becomes insensitive, as the added mass absorbs some of the sound vibrations.

In the past attempts have been made to provide phonograph needles having vertical compliance by osetting the record engaging tip at the end of a relatively long spring member which extends from the shank. One disadvantage of such earlier arrangements is that if a guard is provided it must comprise an additional foot or bumper extending out from the shank of the needle. Another disadvantage of such arrangements is that since the record engaging tip is spaced a considerable distance from the shank, a change in the angle of the tone arm changes the relative positions of the guard and tip with regard to the surface of the record. For example, in a phonograph having an automatic record changer the records are stacked one on top of the other during operation, and the height of the record surface changes with regard to the pivotal .3 point of the base o the tone cuently when only one or two record turntable the relative position of th needle tip and guard with respect to the record urface will be diffe than when ten or twelve or more records are on the turntable. This change in relative position changes the eii'e iveness of any bumper guard which iight be provided.

I have devised and am herewith disclosing and claiming an improved phonograph needle which possesses the features earlier set forth and eliminates the disadvantages found in earier offset type needles.

Referring now to the drawings, in Fig. l a tone arm l carries a needle designated generally at l! in a chuck (not shown), and the record engaging tip of the needle rides in the groove upon the surface of a record I2. The needle is responsive to undulations in the groove and transmits them translating device. In conventional operation the vibrations are translated into electrical variu ations, are ampliiied, and reproduced by means of a speaker or other transducer.

In Figs. 2 and 3, which illustrate the preferred embodiment of the invention, the needle of Fig. l is shown enlarged and removed from the tone arm chuck. The needle comprises an elongated shank member i3 which may be made of a suitable metal or other material. The shank is geneially cylindrical in shape and has a flattened portion i4 which extends from the upper end of the shank along one sideJ for a substantial portion of the length of the shank. This flattened portion serves to indicate the front side of the shank so that the shank may properly positioned in the tone arm chuck, and in addition the shank cooperates with the holding end of a set screw or other holding device on the tone arm so that the needle is held immovabiy in the tono arm chuck.

A liexible member designated generally at l5 is mounted on the shank adjacent one end thereof. In Fig. l, one end of the flexible member is shown as being forced through an opening in the shank, and the member may be held immovable in the shank by welding, sweating, etc. The iiexible member It is in the form of an open ended elongated loop and has a portion 55a which extends away from the shank. The member is bent at 15b to form a portion 50 substantially parallel to the portion lim and which extends back toward the shank, and the member l5 is bent downwardly to form a terminal tip portion 15d which extends below the end of the shank. The tip may itself be adapted to engage the surface of a record, in which event the tip may or may not be of the same material as is the rest of the member l5; or if desired the record engaging portion of the tip may comprise a different metal piece mounted on the member l5, or a jewel or any other device suitable for use as a record engaging tip.

The member l5 is preferably formed of resilient wire, and as shown in Fig. 3, the wire may be flattened to provide additional flexibility.

Figs. d and 5, wherein reference characters ten higher than those used in Figs. 2 and 3 designate similar parts, shows a modiied form o needle comprising an elongated shank member d3 which is attened along part of one side as shown at 24, and at the end of which mounted a iiexible member designated generally at 25. In both Figs. 2 and 4 the exible member is in the form of an open ended elongated loop extending away from and conseare on the as vibrations to a crystal or other the shank in a direction counter to the direction of record movement, and in both of said figures the portion of the resilient member which extends away from said loop is relatively long, being at least or" the order of twice as long as the spacing between the portion of the loop which extends away from the shank and the portion of the loop which extends back toward the shank. Also in Figs. 2 and el the record engaging tip extends bclow the end of the shank and is spaced from a projection or the axis of the shank, said tip being located outside but closely adjacent the periphery of a projection of the end face of the shank. Whereas in Fig. 2 the elliptical loop is formed in a plane transverse of the record surface, in Fig. 4 the loop is formed in a plane substantially parallel to the plane ol the record surface, and consequently in the structure of Fig. 4 the resilient member may be mounted directly at the end of the shank. The substantially horizontally formed loop of Fig. 4 is similar in formation to the vertically formed loop of Fig. 2, resilient member 25 in Fig. 4 having a portion 25a which extends away from the shank, and being bent at 25h to form a portion 25e which extends back toward the shank substantially parallel to the long portion 25a. The ilexible member is then downwardly turned and terminates in a tip portion 25d. While the resilient member 25 may be ilattened if desired, it is here illustrated as a wire or round cross section.

Figs. 6 and 'l illustrate another modification of the invention, reference characters twenty higher than those used in Fig. 2 designating similar parts. A shank 33 is provided similar to -the shank I3, the shank 33 having a flattened portion 34 to engage a set screw or other holding means in a tone arm chuck. A flexible member designated generally at 35 is mounted on the shank adjacent one end thereof, this member being formed as an elongated loop having a portion 35a which extends away from the shank and is bent at 35h to form a portion 35o which extends back toward the shank substantially parallel with the portion 35a. A downwardly'turned terminal tip portion Std extends below the end of the shank 3. rThe portion 35o is flattened to provide additional flexibility.

It will be noted that in each form of the invention the resilient member extends away from the shank in a direction substantially parallel to the plane of the record and to the direction of record movement. In Figs. 2 and 4 the loop extends away from the shank in a direction counter to the direction of record movement, while in Fig. 6 the loop extends away from the shank in the direction of record movement.

In the operation of the device the shank is mounted in a tone arm chuck and extends below the tone arm as shown in Fig. 1. Conventionally the axis of the shank makes an angle of about 211/2 with the vertical when the tone arm is in its normal position with only al few records on the turntable. In this position it will be seen that the record engaging tip rides uponvthe surface of the record while therend of the shank 3 is spaced from the surface of the record. However, should the tone arm be dropped or should abnormal pressure be put upon the tone arm, the resilient member will bend so that the end of the shank i3 is brought into engagement with the record surface before the flexible portion has been ilexed beyond its elastic limit, and without any bottoming of any part of the ilexible portion, thereby protecting the resilient `member against breakage and protecting the undulations in the record grooves against damage. Furthermore, in all forms of the invention the record tip is spaced from a projection of the axis of the shank, being located outside but closely adjacent the periphery of a projection of the end face of the shank. Consequently a relatively long, thin resilient member is provided while at the same time if the angle of the tone arm changes, as if a large number of records are placed on the turntable, the relative positions of the shank end and the record engaging tip are not appreciably changed with reference to the record surface so that the end of the shank acts as a bumper under all conditions upon flexure which is substantially identical despite Variations in tone arm angle. As may be seen in the drawings the loop into which the resilient member is formed extends upwardly slightly above the end of the shank so that there is no posibility that the end of the loop will drag on the record surface.

The relatively long resilient member provides greater improved vertical compliance, and also provides compliance in allV directions in which e force may be exerted on the needle in operation. For example, an irregularity in the bottom of 'the record groove will impart not only a vertical force to the record tip, but also a horizontal force in the direction of motion of the record, and the resultant force will be the vector sum of these two forces. While a needle which has compliance only in a vertical direction would tend to minimize only the vertical component of this resultant force, the needle disclosed herein minimizes both the vertical and horizontal components and consequently renders the resultant force practically negligible since the bend at the outer end of the loop causes the nedle to yield in a horizontal direction.

A needle which is compliant to horizontal forces only in the direction of record movement and not transverse thereto would operate to distort high frequencies, since the high frequency undulations in the record grove project from the groove wall at a very sharp angle. However, no noticeable distortion is present in a needle constructed in accordance with this invention since the relatively long, narrow flexible portion ren ders the needle compliant to all forces in a horizontal plane as well as vertical forces and con- Sequently the needle provides desirably rapid attenuation of high frequency signals, as for example rapid attenuation of frequencies above 5,000 cycles per second. At lower frequencies the undulations project from the groove wall at a smaller angle so no distortion is present.

Furthermore, it will be noted that the guarding of the exible member is accomplished without the use of an extending foot on the shank. Such a foot would increase the mass and inertia of the needle and thereby render it relatively insensitive and increase the cost of manufacture.

In constructing the needle in accordance with this invention, I prefer to form a steel-bodied needle having a record engaging tip of a precious metal alloy, as for example an osmium-ruthemum-platinum alioy composed principally of osmium. The loop into which the resilient member is formed should be elongated and, whether the loop is formed in a vertical plane or in a substantially horizontal plane, the opposite sides of the loop (as for example the portions a and 25o) should be relatively close together when compared with the length of the loop in order to avoid distortion in reproduction. I have also found that the loop should extend from the shank in a direction parallel to the direction of record travel, since a loop extending transverse to the direction of record movement has too little lateral compliance. In the form of the inventionv illustrated in Figs. 4 and 5 the loop should be kept relatively small if whistle and other noises directly from the needle are to be avoided, and in the form of the invention illustrated in Figs. 6 and 7 the loop should be formed in a plane substantially horizontal to the plane of the record surface if whistle is to be avoided.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

l. A phonograph. needle of the character described, comprising: an elongated shank member; and a resilient member in the form of an open ended elongated loop having one end mounted on the shank adjacent one end thereof, Said loop having a relatively long portion extending away from said shank, a portion substantially parallel to said long portion extending back toward said shank, and a terminal downwardly extending tip portion extending below the end oi said shank, both thetip portion and the last mentioned loop portion being outside the periphery of a projection of the end face of said shank.

2. Apparatus of the character claimed in claim l, wherein the length of the portion extending away from said shank is at least of the order of twice the spacing between the portion extending away irom said shank and the portion extending back toward said shank, and the tip portion is closely adjacent the periphery of a projection of the end face of said shank.

3. A phonograph needle of the character described, comprising: an elongated shank member; and a resilient wire member in the form of an open ended elongated loop having one end mounted on the shank adjacent one end thereof, said loop having a relatively long portion extending away from said shank in a direction substantially parallel to the direction of record movement, a portion substantially parallel to said long portion extending back toward but not beneath the periphery of a projection of the end face of said shank, and a terminal downwardly extending tip portion extending below the end of said shank and closely spaced from a projection of the axis of said shank.

4. A phonograph needle of the character described, comprising: an elongated shank member; and a resilient wire member in the form of an open ended elongated loop having one end mounted on the shank adjacent one end thereof, said loop having a relatively long portion extending away from said shank in a direction counter to the direction of record movement, a portion substantially parallel to said long portion extending back towards said shank, and a terminal downwardly extending tip portion extending below the end of said Shank, both the tip portion and the last mentioned loop portion being outside but closely adjacent the periphery of a projection of the end face of said shank, said loop beingformed in a plane transverse to the plane ci the record surface and the length of `the portion extendingr away from saidshank beanopen ended elongated loop` having one end mounted on the shank at one end thereof, said loop havinga relatively long portion extending away from said vshank in a direction counter to the direction of record movement, a portion substantially parallel .to said long portion extending back toward butnot beneath the periphery of a projection voi the end face `of said shank, and a .terminal downwardly extending tip portion extending below the end of said shank and closely spaced from a projection of the axis Vof said shank, said loop being 'formed'ina plane substantially parallel to the plane of therecord surface and the lengthvof the portion extending away from said shank being at least of the order of twice the spacing. between the portion extending away from said shank and the portion extending back toward said shank.

V6. A phonograph needle of the character described, comprising: an elongated shank memn ber; and a resilient wire member in the form o'i an open ended elongated loop having one end mounted on the shank adjacent one end thereof, said loop having a relatively long portion extendingv away from said shank in the direction of record movement, a portion substantially parallel to said long portion extending back towards' said shank, anda terminal downwardly extending tip portion extending below the end of said shank, both the tip portion and the last mentioned loop portion being outside but closely ad- `jacenttlfie.periphery voiV a projection. of the end :faceof said shank, said loopbeing formed in a plane vsubstantially parallel to the plane `of the record surface and said loop having a flattened portion forincreasing the exibility of saidloop.

7. AA phonograph needle of the character described, comprising: an elongated shank section; aljexible section -carried onA said shank,I said flexible sectionhaving a portion extending away from said shank and a portion extending back toward but notbeneath the periphery of aprojectionoi theendfaceof said shank; and aterminal tip section carried on said exible section and extending substantially parallel to a projection of the axis of the shank belowA the end of said shank outside theperiphery of a projection of the'end face-of said shank.

FREDERICK C. HOLTZ, JR.

REFERENCES CITED The following references are 'of record inthe le of this patent:

UNITED STATES PATENTS Number v Name Date 1,160,146 Dayan Nov. 16, 1915 1,185,266 Vesey May 30, 1916 1,435,095 Adams Nov. 7, 1922 2,320,416 Dally June 1, 1943 2,325,343 Semple July 27, 1943 2,432,444 Roberts Dec. 9,1947

v2,438,111 Campbell Mar. 23, 1948 2,452,304 Hutter Oct. 26, 1948 2,499,196 Mencke Feb. 28, 1950 FOREIGN PATENTS Number Country Date 350,887 Great .Britain June 18, 1931

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