US2502661A - Phonograph stylus - Google Patents

Description

April 4, 1950 M- A. MILLER 2,502,661

PHONOGRAPH STYLUS Filed March 8, 1948 IN V EN TOR.

Patented Apr. 4, 1950 UNITED STATES attend rem OFFICE 4 Claims.

My invention relates to a stylus for tracking in the grooves of a phonograph disc record. More particularly I am here concerned with certain details of construction in which three parts are inseparably united to provide an improved stylus having certain advantages as will hereafter be noted.

Referring now to the drawing which illustrates two embodiments of my invention Figure 1 is a longitudinal section through the bottom cap and a portion of the shank which is comprised in the stylus, the needle element being shown in elevation;

Fig. 2 is a bottom plan view thereof;

Fig. 3 is an exploded perspective view of the parts entering into the construction of Fig. 1;

Fig. 4, which is a view similar to Fig. 1, shows a modification in the form of the needle element and its manner of connection with the associated parts;

Fig. 5 is a bottom plan view thereof; and

Fig. 6 is an exploded view in perspective of the parts entering into the construction of Fig. 4.

The stylus here shown is of the type which includes a shank S having in its upper end portion a flatted face ii! to receive pressure from the usual retaining screw when the stylus is applied to a reproducer of approved form. In the form of Figs. 1-3, the shank is bent at I! so that its two end portions are angularly related to each other. Throughout its lower end region I2, commencing with a shoulder E3, the shank is reduced in diameter to receive thereupon a shoe l4 which reaches upwardly to abut the shoulder l3, as shown clearly in Fig. 1. A bead l5 extends circumferentially of the shank in its lower end region I2, and the shoe when forced thereover will be frictionally locked thereto over the bottom end of the shank.

Through the shoe and lower end region l2 of the shank, and close to the bottom end thereof, is a transverse passageway l6 formed as by a boring operation for receiving the shank ll of a needle N. As shown in Fig. 1, the shank of this needle extends through the shoe and stylus shank in a plane which is perpendicular to the axis thereof. The needle may be secured in this position by a friction fit as will be hereinafter explained. At the point about where it emerges from the shoe the needle shank is bent as at i8 so that it may incline downwardly and present its laterally-turned pointed end l9 directly toward a disc record for tracking in the grooves thereof.

In this construction the shoe is desirably made Cl. Wi l-38) of some composition material such as nylon or other suitable plastic. When fitted in place it becomes an inseparable part of the stylus shank. Desirably the shoe is rounded off at its bottom end so that, if it should drop onto a record in position for play, there will be no sharp corner to engage therewith. It also provides a bearing of enlarged radius for supporting the needle in its mounting. In operation, vibrations transmitted through the needle are largely dampened by the plastic shoe so that transmission of such vibrations through the stylus shank to the reproducer is stopped or greatly minimized.

Referring now to Figs. 4-6, the construction of this stylus is the same as that already described in that it comprises the same three major elements, viz., a shank S with fiat face 28 and a lower end portion 22 of reduced diameter, together with a shoe Z lwhich is fitted thereover and inseparably secured thereto with the aid of one or more beads 25 circumferentially thereof; also a needle N, which is entered through a transverse opening 26 in the shoe 24 and lower end portion of the stylus shank, is supported thereby in operative position for tracking in the grooves of a phonograph record. In this construction, however, the stylus shank is straight so that the shoe 24 will be coaxial therewith for its entire length. The transverse bore 26 through the shoe and shank, however, is not perpendicular to the axis of these parts, but is oblique thereto whereby the needle N is downwardly pointed as it emerges from the shoe. A curve 28 may be given to the needle to further direct its acting end 29 downwardly whereby to engage with the phonograph record at a desired angle. Except for the changes noted, this construction is the same as the one previously described.

The stylus shank, in each of the illustrated constructions, is metallic, steel or aluminum (preferably the latter) being suggested as most suitable. The transverse hole It or 25, as the case may be, is initially round, but the preferred cross-sectional form of the needle N is otherwise. As best shown in Fig. 3, the needle is flattened top and bottom for substantially its entire length whereby to reduce its vertical dimension. When the needle so formed is forced within the round hole It of the shank S, there is a tendency for the softer metal, i. e., the aluminum, to be cut somewhat in order to accommodate the angular corners of the needle which is made of a harder metal. As suitable for this purpose I would suggest stainless steel which has spring properties to a substantial degree. When the flattened needle N is thus forced into the transverse round opening 16 of the stylus shank, it remains locked against rotation and with its acting end l9 pointed downwardly, as shown. Since the vertical crosssectional dimension of the needle is substantially less than is its horizontal dimension, the resiliency of the needle is enhanced, so that it will readily flex in a vertical plane if and when it meets with a sudden shock while in engagement with the disc record. Should the stylus, while held in the reproduce-r, be dropped suddenly onto the record, the needle will then flex upwardly as to obviate damage to the record; and if the shock be sufficiently great the bottom end of the shoe will descend into engagement with the record, but without any appreciable damage thereto.

The present stylus is advantageous in the several respects noted. It may also be produced to sell at an attractive price, since the cost of its manufacture is not excessive. Initially the shoe is frictionally locked to the stylus shank lower end region, but after the needle has been anchored in its tranverse opening Hi, this lock will become positive. Accordingly there will be no liability of disassembly of any of the three stylus elements, one from another, so that operation of the multi-piece stylus may be assured for an extended period in the usual way.

I claim:

1. A stylus in which is comprised a metallic shank with a transverse bore therethrough, a plastic shoe fitted over and surrounding the shank lower end and extending upwardly therealong past the transverse bore and formed therethrough with a bore in continuation of that in the shank, and a metallic needle anchored in the transverse bore of the shank and shoe and extended outwardly and downwardly therefrom for engaging with agrooved record.

2. A stylus according to claim 1 in which the transverse bore is round and the needle is nonround in cross-section and of a size adapted for anchorage within the bore when some of the engaged metal of one of these parts is displaced by forcibly advancing the needle endwise into the bore.

3. A stylus according to claim 1 in which the transverse bore is round and the needle is nonround in .cross section and formed of a metal that is harder than that composing the shank and of a size adapted for an anchorage within the bore when the metal surrounding the latter is displaced by forcibly advancing the needle endwise into the bore.

4. A stylus in which is comprised a metallic shank having a lower end portion of reduced diameter and provided thereon with a circumferential bead, a plastic shoe fitted over and surrounding the lower shank end of reduced diameter and extending upwardly therealong to engage with the bead, there being a transverse bore formed through the shank and shoe, and the bottom end of the shoe being rounded at its juncture with the peripheral side walls thereof, and a metallic needle anchored in the transverse bore of the shank and shoe and extending therefrom in one direction only both outwardly and downwardly for engaging with the groove of a record.

MELVILLE A. MILLER.

REFERENCES CITED UNITED STATES PATENTS Name Date Andres Aug. 10, 1943 Number

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