US1478192A - Phonographic stylus - Google Patents

Description

Dec. 18,1923. 1,478,192

v R. c. WADE PHONOGRAPHIC STYLUS Filed Sent. 1919 reams Dec. is, 1923.;

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ROBERT C. WADE}, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE TdIJOFONE COITIPANY, A

CORPORATION OF ILLINOIS.

PHONOGRAPHIC STYLUS.

Application filed September 2, 1919. Serial No. 321,218.

To aZZ whom it may concern:

Be it known that 1, ROBERT C. WADE, a citizen of the United States, residing at the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Phonographic Styli, of which the following is a specification.

uniform rigidity My invention relates to the devices by which sound records are made audible in sound reproducing machines and it has particularly to do with the needles or styli which are used in that connection, and with the construction and character thereof.

The effect of all standard needles or styli as attached to the sound box of a sound reproducing machine is that of a substantially throughout their length the bearing end thereof operating in the record groove which has an almost infinite number of projections or undulations.- And there has been theory and practice to the effect that the bearing end should be of hard material relatively to the reproduction inequalities of the sound record. But while that portion of a stylus which is clamped to the sound box should be adapted to solid and nonvibrating connection therewith, T have discovered that it is also important that the sound reproducing portion, that which comes in operative contact with the sound record, Should be soft in quality and resilient in action.

In my invention I have, therefore, provided a composite stylus in which the shank or holding member and the point 'or reproducing member have esentially difierent physical characteristics. That portion which is in immediate relation to the record is adapted to conform itself to the general style of groove used, and it is also elastic or resilient so that it will follow tions on the records of any standard construction.

That portion of the stylus in which the bearing end is mounted is a relatively large and rigid structure and its action is not that of conforming itself to the inequalities or undulations of the record but of receiving and transmitting the vibrations of the resilient member to the sound box.

- The principles of my invention are illustrated in the drawings in which Fig. 1 represents my improved stylus in approximately natural size. Fig. 2shows the same the undulaof within certain greatly enlarged, Fig. 3 represents the resilient member still further enlarged in relation to a section of a phonographic record.

Further describing my invention with reference to the drawings, 1 is the resilient member which is in contact with the record and is adapted to ride in the grooves thereof. It is securely fastened into the holding member or shank 2, which further may provided with the head 3 and flange 4:- The stylus may be constructed in many ways, but

it is important to secure the sensitive resilient point in the nonresilient and relativelylarge and heavy shank to which for further solidity may be added the enlarged portions of the head and flange.

It is diflicult to illustrate graphically the great disparity of thickness and weight between the resilient point and the portion on which it is mounted. I willhowever, say that in practice the resilient member consists of spring wire of suitable character as to softness and of a diameter approximately .007 of an inch. The shank wire which is adapted for general use and to be received within the clamping members of sound boxes as ordinarily constructed may be any suitable material of a diameter approx1- mately .067 of an inc I prefer to make the shank of brass or copper wire and to so treat it that it will be very soft in quality. This is for the double purpose of causing it to form readily and securely about the vinserted point and of eliminating any springiness which might give rise to external vibrations, and without interferin with -its sound conductivity. This quality aids materially in eliminatng the so-called needle sing which is present in styli which are of homogeneous quality throughout their length.

In the process of manufacture the members are united in any suitable way. A slit, indentation or other opening may be in the soft metal blank from which the shank is made. One end of the resilient member is inserted in the opening and the edges of the shank member are then swaged in suitable dies down upon the resilient member. I prefer to have the dies so constructed that the thickness of the-shank adjacent to the inserted member is substantially increased forming the head 3.- The formation of this head is not absolutely essential and the size therelimits is not greatly material, but it does add stren to the construction and it a and non-vibrative character of the structure relatively to the resilient member mounted thereon. In practice I prefer to make the greatest diameter of the head 3 about .09 of an inch in diameter and that of the flange 4 about .125 of an inch.

It further should be noted that the resilient member should be made of wire of uniform diameter cut squarely across the lower end so that the'latter shall form a h and security ds to the weight of this portion plane at substantially right angles to the should be of such which would escape'a more longitudinal axis of the W1re. The reproducing styliof sound reproducing machines are usually inclined to the record at an angle of about The spring or elastic contactmember of my invention is of a diameter fairly corresponding to the width of the record grooves. Its relation thereto is illustrated in .Fig. 3 in which 6 is the plane face of the elastic member 1 As the record is started'moving under the stylus the latter will ride upon the thin edges 7 of the plane face.

The material of the contact member quality as to softness that it will readily be shaped to the general formation of the record groove by the abrasive properties of the record material. When the record starts revolving, the spring contact member will immediately assume the proper form and settle into the groove. It is immaterial whether the roove is of the vertical or lateral type.' fts elasticity .will enable it, while the record is revolving, to follow the exact contour of the grooves III'QSPGOiJiVG of the class to which the groove belongs. That is, it will traverse the exact profile of each undulation therein and thus conduct through the shank to the sound box, the reproduction of every original sound vibration as recorded by such undulations.

vAn even and uniform tone is thus produced,

and matter in the sound record is developed rigid reproduc- And the character of the mation point.-

prevent the scratching sounds terial will which are and by those which are comparatively inflexible in character.

As the contact member is of uniform diameter a large number of records may be played before the available length of the contact member is exhausted. In fact, the entire wire may be jury to the record which may be played to such time as the soft metal shank will ride on the surface of the record. But this is not advisable or contemplated in my invention, for the resilient quality of the contact member will be lost when it becomes excessively shortened by wear.

1. In a phonograph stylus, a highly resilient tip member adapted to engage the sound record record, the pro ecting portion of said tip member being of comparatively great length and of a diameter substantially corresponding to the width of the widest part of the record groove, said resilient member being of soft material capable of being readily shaped to the grooves of a phonograph record.

2. phonograph stylus comprising a highly resilient tip member adapted to engage the sound record groove of a phonograph record, the projecting portion of said tip member being of comparatively great length and of a diameter substantially corresponding to the width of the widest part of the record groove, said resilient member being of soft material capable of being readily shaped to the grooves of a phonograph record, and a shank of relative] softnonvibrative material in which said tip member is axially fixed.

In witness whereof, I have hereunto subscribed my name this 29th day of August, 1919, at Chicago, Cook Count Illinois.

ROBERT C. WADE.

produced by solid stylus points worn away without ingroove of a phonograph

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