US958412A - Stylus for sound-reproducing machines. - Google Patents

Description

S. LEVIN. STYLUS FOR SOUND. REPRODUUING MAGHINES. APPLICATION FILED JUNE 15, 1909.

958,412. Patented May 17, 1910.

.anuzntoz SAMUEL LEVIIT, OF HIGHLAND PARK, ILLINOIS.

STYLUS FOR SOUND-BEPRODUCING MACHINES.

Specification of Letters Patent. Patented 'Mjay 1'1 1910.

application flledjune 15, 1909. Serial No. 502,297.

To all whom it may concern:

Be it known that I, SAMUEL LEVIN, a citizen of the United States, residing at High land Park, in the county of Lake and State of Illinois, have invented a new and useful Stylus for Sound Reproducing Machines, of which the following is a specification.

This invention has reference to improvements in styli for sound reproducing machines and is designed more especial y for use in connection with-the disk or gramophone type of sound reproducing machine.

In the gramophone type of sound reproducing'maohine the sound record is in the form of a sinuous groove of even depth and the diaphragm of the reproducing sound box is vibrated by the engagement of the'side walls of the groove with the stylus, the action of the groove on the stylus being usually from both walls of the record groove, but one wall receives more of the wear from the stylus than the other because in this type of machine the sound record groove itself is utilized for feeding the sound box' across the record tablet. The stylus most generally employed in connection with sound reproducing machines of the gramophone type is in the, form of a steel needle point which enters and substantially fills the groove from wall to wall, or if not, quickly becomes worn to the proper shape, but the continual wear of the record groove against the steel needle, though most pronounced on the needle, is still noticeable after a number of reproductions upon the record tablet itself. This is particularly true should the operator omit to change the stylus for each new tablet reproduced or after one or two reproductions of the same tablet. The necessity of changing the stylus for .each reproduction becomes onerous or the chan ing of the stylus isnegleetedthrough care essness. It is the object of the present invention to avoid these troubles and at the same time rovide a stylus which after. being once adjusted to the sound box may be used again and again indefinitely without the necessity of change and without material wear upon the sound record tablet.

It has long been recognized that a ewel point because of its hardness and wear resisting qualities as well as its rlgidlty would make an ideal reproducing stylus for the gramophone type of sound tablet. However such jewel ,points have been patterned after the usual steel needle point used in c0nnection with sound reproducing machines of the gramophone type, but because of the brittleness of the material used, such stylihave not proved successful since the points become qulckly broken and the sharp edges thus produced are very destructive to the record tablet. 7

By the present invention the styli are made with jewels for the activev end and these jewels are so constructed as to no longer be fragile while ractieal tests have shown that the life of 1; esestyli is almost unlimited. 7

The invention will be best understood from a consideration of the following detail description taken in connection with the accompanying drawings forming a part of this specification, in which drawings,

Figure 1 is an elevation of astylus constructed in accordance with the present invention. Fig. 2 is a longitudinal section thereof. Fig. 3 is a bottom plan view, and

Fig. 4 is a view of a somewhat. modified form.

In accordance with the resent invention the stylus is made of a bo y portion in the shape of a tube 1 ex anded at one end into a holder 2 of suitab e shape to receive and retain a substantially plano-convex jewel 3. This jewel may be of any suitable material, but it is preferably made of garnet, though sapphire or any of the other jewels used in connection with sound reproducing machines may be utilized if so desired The material employed forms no necessary part of the present invention- The head 2 may be soshaped as to grasp the jewel 3 so firmly that the latter is incapable of inde endent movement with relation to the hea or the stem 1.

Of course it will be understood that the The stem 1 being tubular may be" rein-- forced by a central core- 4 of steel or other hard resisting material,- or the stem 1 and head 2 may be made of a solid piece of metal, such as steel and the jewel 3 may be set therein in firm engagement with the head 2. The core 4 may be omitted from the tubular stem for soft efi'ects, while for loud effects the core may be used or the stem maiy be solid.

' one face substantially flat and the other face convex.

The stylus as a whole is made of about the size of the ordinary steel styli used in the gramophone ty e of sound. reproducing machines, the showing of the drawings being enlarged.

When the stylus is in place in the sound box the convex side of the stylus is against the feeding wall of the sound groove while the flat side of the stylus is toward the nonfeeding wall of the groove.

.The walls of the recordgroove are either curved on arcs described about the center of the tablet as an axis or these walls are in the form of sharper curves due to the sinuosities of the groove corresponding to sound waves.

' The convex side of the jewel point 3 en gages against the active wall of the groove,

' and being rounded has no wearing effect upon the wall of the groove such as occurs from the tongue at the end of the steel ne dle which is formed on the needle stylus asvgoon asthe tablet has made a few turns. ec'ause of the plane surface of the stylus presented to the inactive wall of the groove there is no material wearing of this wall.

By making the jewel nearly or quite cir-.

cular so far as the projecting portion of the jewel is concernedit may be made quite bulky and .corres ondingly strong and in i this manner the ragility of jewel styli as heretofore provided for the gramophone type of reproducing machines is avoided and t e stylus becomes a practical device.

-stiffening the same.

What is claimed is 1. A reproducin stylus for sound reproducing machines of the gramophone or disk type, having its active end formed of a plano-convex jewel with the plane and convex surfaces joined by a rounded edge.

2. A stylus for sound reproducing machines of the gramophone or disk type elongated in the direction of travel ofthe sound record groove and 'having the face against which the propellingwall of the sound record groove acts convex.

3. A stylus for sound reproducing machines of the gramophone or disk type elongated in the direction of travel of the sound record groove and having the face against which the propelling wall of the sound recordgroove acts-convex and the opposite face plane.

4. A stylus for sound reproducing machines, comprising a metallic stem terminating in a head, and a piano-convex jewel mounted in said head and constituting the active end of the stylus, the convex side of the jewel bein adapted to receive the feed ing thrust of t e sound record groove.

5. A stylus for sound reproducing machines comprising an' active end formed of a jewel, a tubular stem having one end formed to'receive and retain the jewel point, and a core within the tubular stem for 6. A stylus for sound reproducing machines having an active end in the form of a jewel of reater extent in the direct-ion of the length o the sound record groove than in the direction of the width of the groove, and

having a rounded edge adapted to be en-' gaged by the propelling wall of the groove.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature in the presence of two witnesses.

I SAMUEL LEVIN.

Witnesses:

FRED SCHAEFER, H. L. BOWEN.

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